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 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017 Christopher Allan Webber@*
49 Copyright @copyright{} 2017, 2018, 2019, 2020 Marius Bakke@*
50 Copyright @copyright{} 2017, 2019, 2020 Hartmut Goebel@*
51 Copyright @copyright{} 2017, 2019, 2020 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019, 2020 Tobias Geerinckx-Rice@*
53 Copyright @copyright{} 2017 George Clemmer@*
54 Copyright @copyright{} 2017 Andy Wingo@*
55 Copyright @copyright{} 2017, 2018, 2019, 2020 Arun Isaac@*
56 Copyright @copyright{} 2017 nee@*
57 Copyright @copyright{} 2018 Rutger Helling@*
58 Copyright @copyright{} 2018, 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 the
146 @uref{https://translationproject.org/domain/guix-manual.html, Translation
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.
251 * Invoking guix environment:: Setting up development environments.
252 * Invoking guix pack:: Creating software bundles.
253 * The GCC toolchain:: Working with languages supported by GCC.
254 * Invoking guix git authenticate:: Authenticating Git repositories.
256 Programming Interface
258 * Package Modules:: Packages from the programmer's viewpoint.
259 * Defining Packages:: Defining new packages.
260 * Defining Package Variants:: Customizing packages.
261 * Build Systems:: Specifying how packages are built.
262 * Build Phases:: Phases of the build process of a package.
263 * Build Utilities:: Helpers for your package definitions and more.
264 * The Store:: Manipulating the package store.
265 * Derivations:: Low-level interface to package derivations.
266 * The Store Monad:: Purely functional interface to the store.
267 * G-Expressions:: Manipulating build expressions.
268 * Invoking guix repl:: Programming Guix in Guile.
272 * package Reference:: The package data type.
273 * origin Reference:: The origin data type.
277 * Invoking guix build:: Building packages from the command line.
278 * Invoking guix edit:: Editing package definitions.
279 * Invoking guix download:: Downloading a file and printing its hash.
280 * Invoking guix hash:: Computing the cryptographic hash of a file.
281 * Invoking guix import:: Importing package definitions.
282 * Invoking guix refresh:: Updating package definitions.
283 * Invoking guix lint:: Finding errors in package definitions.
284 * Invoking guix size:: Profiling disk usage.
285 * Invoking guix graph:: Visualizing the graph of packages.
286 * Invoking guix publish:: Sharing substitutes.
287 * Invoking guix challenge:: Challenging substitute servers.
288 * Invoking guix copy:: Copying to and from a remote store.
289 * Invoking guix container:: Process isolation.
290 * Invoking guix weather:: Assessing substitute availability.
291 * Invoking guix processes:: Listing client processes.
293 Invoking @command{guix build}
295 * Common Build Options:: Build options for most commands.
296 * Package Transformation Options:: Creating variants of packages.
297 * Additional Build Options:: Options specific to 'guix build'.
298 * Debugging Build Failures:: Real life packaging experience.
302 * Using the Configuration System:: Customizing your GNU system.
303 * operating-system Reference:: Detail of operating-system declarations.
304 * File Systems:: Configuring file system mounts.
305 * Mapped Devices:: Block device extra processing.
306 * User Accounts:: Specifying user accounts.
307 * Keyboard Layout:: How the system interprets key strokes.
308 * Locales:: Language and cultural convention settings.
309 * Services:: Specifying system services.
310 * Setuid Programs:: Programs running with root privileges.
311 * X.509 Certificates:: Authenticating HTTPS servers.
312 * Name Service Switch:: Configuring libc's name service switch.
313 * Initial RAM Disk:: Linux-Libre bootstrapping.
314 * Bootloader Configuration:: Configuring the boot loader.
315 * Invoking guix system:: Instantiating a system configuration.
316 * Invoking guix deploy:: Deploying a system configuration to a remote host.
317 * Running Guix in a VM:: How to run Guix System in a virtual machine.
318 * Defining Services:: Adding new service definitions.
322 * Base Services:: Essential system services.
323 * Scheduled Job Execution:: The mcron service.
324 * Log Rotation:: The rottlog service.
325 * Networking Services:: Network setup, SSH daemon, etc.
326 * Unattended Upgrades:: Automated system upgrades.
327 * X Window:: Graphical display.
328 * Printing Services:: Local and remote printer support.
329 * Desktop Services:: D-Bus and desktop services.
330 * Sound Services:: ALSA and Pulseaudio services.
331 * Database Services:: SQL databases, key-value stores, etc.
332 * Mail Services:: IMAP, POP3, SMTP, and all that.
333 * Messaging Services:: Messaging services.
334 * Telephony Services:: Telephony services.
335 * Monitoring Services:: Monitoring services.
336 * Kerberos Services:: Kerberos services.
337 * LDAP Services:: LDAP services.
338 * Web Services:: Web servers.
339 * Certificate Services:: TLS certificates via Let's Encrypt.
340 * DNS Services:: DNS daemons.
341 * VPN Services:: VPN daemons.
342 * Network File System:: NFS related services.
343 * Continuous Integration:: The Cuirass service.
344 * Power Management Services:: Extending battery life.
345 * Audio Services:: The MPD.
346 * Virtualization Services:: Virtualization services.
347 * Version Control Services:: Providing remote access to Git repositories.
348 * Game Services:: Game servers.
349 * PAM Mount Service:: Service to mount volumes when logging in.
350 * Guix Services:: Services relating specifically to Guix.
351 * Linux Services:: Services tied to the Linux kernel.
352 * Hurd Services:: Services specific for a Hurd System.
353 * Miscellaneous Services:: Other services.
357 * Service Composition:: The model for composing services.
358 * Service Types and Services:: Types and services.
359 * Service Reference:: API reference.
360 * Shepherd Services:: A particular type of service.
362 Installing Debugging Files
364 * Separate Debug Info:: Installing 'debug' outputs.
365 * Rebuilding Debug Info:: Building missing debug info.
369 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
370 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
375 @c *********************************************************************
377 @chapter Introduction
380 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
381 using the international phonetic alphabet (IPA).} is a package
382 management tool for and distribution of the GNU system.
383 Guix makes it easy for unprivileged
384 users to install, upgrade, or remove software packages, to roll back to a
385 previous package set, to build packages from source, and generally
386 assists with the creation and maintenance of software environments.
389 @cindex GuixSD, now Guix System
390 @cindex Guix System Distribution, now Guix System
391 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
392 complements the available tools without interference (@pxref{Installation}),
393 or you can use it as a standalone operating system distribution,
394 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
395 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
396 group everything under the ``Guix'' banner since, after all, Guix System is
397 readily available through the @command{guix system} command, even if you're
398 using a different distro underneath!}. @xref{GNU Distribution}.
401 * Managing Software the Guix Way:: What's special.
402 * GNU Distribution:: The packages and tools.
405 @node Managing Software the Guix Way
406 @section Managing Software the Guix Way
408 @cindex user interfaces
409 Guix provides a command-line package management interface
410 (@pxref{Package Management}), tools to help with software development
411 (@pxref{Development}), command-line utilities for more advanced usage
412 (@pxref{Utilities}), as well as Scheme programming interfaces
413 (@pxref{Programming Interface}).
415 Its @dfn{build daemon} is responsible for building packages on behalf of
416 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
417 binaries from authorized sources (@pxref{Substitutes}).
419 @cindex extensibility of the distribution
420 @cindex customization, of packages
421 Guix includes package definitions for many GNU and non-GNU packages, all
422 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
423 user's computing freedom}. It is @emph{extensible}: users can write
424 their own package definitions (@pxref{Defining Packages}) and make them
425 available as independent package modules (@pxref{Package Modules}). It
426 is also @emph{customizable}: users can @emph{derive} specialized package
427 definitions from existing ones, including from the command line
428 (@pxref{Package Transformation Options}).
430 @cindex functional package management
432 Under the hood, Guix implements the @dfn{functional package management}
433 discipline pioneered by Nix (@pxref{Acknowledgments}).
434 In Guix, the package build and installation process is seen
435 as a @emph{function}, in the mathematical sense. That function takes inputs,
436 such as build scripts, a compiler, and libraries, and
437 returns an installed package. As a pure function, its result depends
438 solely on its inputs---for instance, it cannot refer to software or
439 scripts that were not explicitly passed as inputs. A build function
440 always produces the same result when passed a given set of inputs. It
441 cannot alter the environment of the running system in
442 any way; for instance, it cannot create, modify, or delete files outside
443 of its build and installation directories. This is achieved by running
444 build processes in isolated environments (or @dfn{containers}), where only their
445 explicit inputs are visible.
448 The result of package build functions is @dfn{cached} in the file
449 system, in a special directory called @dfn{the store} (@pxref{The
450 Store}). Each package is installed in a directory of its own in the
451 store---by default under @file{/gnu/store}. The directory name contains
452 a hash of all the inputs used to build that package; thus, changing an
453 input yields a different directory name.
455 This approach is the foundation for the salient features of Guix: support
456 for transactional package upgrade and rollback, per-user installation, and
457 garbage collection of packages (@pxref{Features}).
460 @node GNU Distribution
461 @section GNU Distribution
464 Guix comes with a distribution of the GNU system consisting entirely of
465 free software@footnote{The term ``free'' here refers to the
466 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
467 users of that software}.}. The
468 distribution can be installed on its own (@pxref{System Installation}),
469 but it is also possible to install Guix as a package manager on top of
470 an installed GNU/Linux system (@pxref{Installation}). When we need to
471 distinguish between the two, we refer to the standalone distribution as
474 The distribution provides core GNU packages such as GNU libc, GCC, and
475 Binutils, as well as many GNU and non-GNU applications. The complete
476 list of available packages can be browsed
477 @url{https://www.gnu.org/software/guix/packages,on-line} or by
478 running @command{guix package} (@pxref{Invoking guix package}):
481 guix package --list-available
484 Our goal is to provide a practical 100% free software distribution of
485 Linux-based and other variants of GNU, with a focus on the promotion and
486 tight integration of GNU components, and an emphasis on programs and
487 tools that help users exert that freedom.
489 Packages are currently available on the following platforms:
494 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel.
497 Intel 32-bit architecture (IA32), Linux-Libre kernel.
500 ARMv7-A architecture with hard float, Thumb-2 and NEON,
501 using the EABI hard-float application binary interface (ABI),
502 and Linux-Libre kernel.
505 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
508 @uref{https://hurd.gnu.org, GNU/Hurd} on the Intel 32-bit architecture
511 This configuration is experimental and under development. The easiest
512 way for you to give it a try is by setting up an instance of
513 @code{hurd-vm-service-type} on your GNU/Linux machine
514 (@pxref{transparent-emulation-qemu, @code{hurd-vm-service-type}}).
515 @xref{Contributing}, on how to help!
517 @item mips64el-linux (deprecated)
518 little-endian 64-bit MIPS processors, specifically the Loongson series,
519 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
520 supported; in particular, there is no ongoing work to ensure that this
521 architecture still works. Should someone decide they wish to revive this
522 architecture then the code is still available.
526 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
527 configuration and Guix takes care of instantiating the configuration in a
528 transactional, reproducible, and stateless fashion (@pxref{System
529 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
530 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
531 Manual}), the well-known GNU utilities and tool chain, as well as the
532 graphical environment or system services of your choice.
534 Guix System is available on all the above platforms except
535 @code{mips64el-linux}.
538 For information on porting to other architectures or kernels,
541 Building this distribution is a cooperative effort, and you are invited
542 to join! @xref{Contributing}, for information about how you can help.
545 @c *********************************************************************
547 @chapter Installation
549 @cindex installing Guix
552 We recommend the use of this
553 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
554 shell installer script} to install Guix on top of a running GNU/Linux system,
555 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
556 with the installation of the package manager, which can be done on top of a
557 running GNU/Linux system. If, instead, you want to install the complete GNU
558 operating system, @pxref{System Installation}.} The script automates the
559 download, installation, and initial configuration of Guix. It should be run
563 @cindex foreign distro
564 @cindex directories related to foreign distro
565 When installed on a foreign distro, GNU@tie{}Guix complements the available
566 tools without interference. Its data lives exclusively in two directories,
567 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
568 such as @file{/etc}, are left untouched.
570 Once installed, Guix can be updated by running @command{guix pull}
571 (@pxref{Invoking guix pull}).
573 If you prefer to perform the installation steps manually or want to tweak
574 them, you may find the following subsections useful. They describe the
575 software requirements of Guix, as well as how to install it manually and get
579 * Binary Installation:: Getting Guix running in no time!
580 * Requirements:: Software needed to build and run Guix.
581 * Running the Test Suite:: Testing Guix.
582 * Setting Up the Daemon:: Preparing the build daemon's environment.
583 * Invoking guix-daemon:: Running the build daemon.
584 * Application Setup:: Application-specific setup.
585 * Upgrading Guix:: Upgrading Guix and its build daemon.
588 @node Binary Installation
589 @section Binary Installation
591 @cindex installing Guix from binaries
592 @cindex installer script
593 This section describes how to install Guix on an arbitrary system from a
594 self-contained tarball providing binaries for Guix and for all its
595 dependencies. This is often quicker than installing from source, which
596 is described in the next sections. The only requirement is to have
599 @c Note duplicated from the ``Installation'' node.
601 We recommend the use of this
602 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
603 shell installer script}. The script automates the download, installation, and
604 initial configuration steps described below. It should be run as the root
605 user. As root, you can thus run this:
609 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
610 chmod +x guix-install.sh
614 When you're done, @pxref{Application Setup} for extra configuration you
615 might need, and @ref{Getting Started} for your first steps!
618 Installing goes along these lines:
622 @cindex downloading Guix binary
623 Download the binary tarball from
624 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
625 where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
626 @code{i686} (32-bits) machine already running the kernel Linux, and so on
627 (@pxref{GNU Distribution}).
629 @c The following is somewhat duplicated in ``System Installation''.
630 Make sure to download the associated @file{.sig} file and to verify the
631 authenticity of the tarball against it, along these lines:
634 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
635 $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
638 If that command fails because you do not have the required public key,
639 then run this command to import it:
642 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
643 -qO - | gpg --import -
647 and rerun the @code{gpg --verify} command.
649 Take note that a warning like ``This key is not certified with a trusted
650 signature!'' is normal.
652 @c end authentication part
655 Now, you need to become the @code{root} user. Depending on your distribution,
656 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
660 # tar --warning=no-timestamp -xf \
661 /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
662 # mv var/guix /var/ && mv gnu /
665 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
666 The latter contains a ready-to-use profile for @code{root} (see next
669 Do @emph{not} unpack the tarball on a working Guix system since that
670 would overwrite its own essential files.
672 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
673 not emit warnings about ``implausibly old time stamps'' (such
674 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
676 They stem from the fact that all the
677 files in the archive have their modification time set to 1 (which
678 means January 1st, 1970). This is done on purpose to make sure the
679 archive content is independent of its creation time, thus making it
683 Make the profile available under @file{~root/.config/guix/current}, which is
684 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
687 # mkdir -p ~root/.config/guix
688 # ln -sf /var/guix/profiles/per-user/root/current-guix \
689 ~root/.config/guix/current
692 Source @file{etc/profile} to augment @env{PATH} and other relevant
693 environment variables:
696 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
697 source $GUIX_PROFILE/etc/profile
701 Create the group and user accounts for build users as explained below
702 (@pxref{Build Environment Setup}).
705 Run the daemon, and set it to automatically start on boot.
707 If your host distro uses the systemd init system, this can be achieved
710 @c Versions of systemd that supported symlinked service files are not
711 @c yet widely deployed, so we should suggest that users copy the service
714 @c See this thread for more information:
715 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
718 # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
719 ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
721 # systemctl enable --now gnu-store.mount guix-daemon
724 If your host distro uses the Upstart init system:
727 # initctl reload-configuration
728 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
733 Otherwise, you can still start the daemon manually with:
736 # ~root/.config/guix/current/bin/guix-daemon \
737 --build-users-group=guixbuild
741 Make the @command{guix} command available to other users on the machine,
745 # mkdir -p /usr/local/bin
747 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
750 It is also a good idea to make the Info version of this manual available
754 # mkdir -p /usr/local/share/info
755 # cd /usr/local/share/info
756 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
760 That way, assuming @file{/usr/local/share/info} is in the search path,
761 running @command{info guix} will open this manual (@pxref{Other Info
762 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
766 @cindex substitutes, authorization thereof
767 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
768 (@pxref{Substitutes}), authorize them:
771 # guix archive --authorize < \
772 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
776 Each user may need to perform a few additional steps to make their Guix
777 environment ready for use, @pxref{Application Setup}.
780 Voilà, the installation is complete!
782 You can confirm that Guix is working by installing a sample package into
789 The binary installation tarball can be (re)produced and verified simply
790 by running the following command in the Guix source tree:
793 make guix-binary.@var{system}.tar.xz
797 ...@: which, in turn, runs:
800 guix pack -s @var{system} --localstatedir \
801 --profile-name=current-guix guix
804 @xref{Invoking guix pack}, for more info on this handy tool.
807 @section Requirements
809 This section lists requirements when building Guix from source. The
810 build procedure for Guix is the same as for other GNU software, and is
811 not covered here. Please see the files @file{README} and @file{INSTALL}
812 in the Guix source tree for additional details.
814 @cindex official website
815 GNU Guix is available for download from its website at
816 @url{https://www.gnu.org/software/guix/}.
818 GNU Guix depends on the following packages:
821 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
823 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
826 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
827 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
828 Guile,, gnutls-guile, GnuTLS-Guile});
830 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
832 @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib};
833 @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
834 @item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi};
836 @c FIXME: Specify a version number once a release has been made.
837 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.3.0
839 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
841 @item @url{https://www.gnu.org/software/make/, GNU Make}.
844 The following dependencies are optional:
848 @c Note: We need at least 0.13.0 for #:nodelay.
849 Support for build offloading (@pxref{Daemon Offload Setup}) and
850 @command{guix copy} (@pxref{Invoking guix copy}) depends on
851 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
852 version 0.13.0 or later.
855 @uref{https://notabug.org/guile-zstd/guile-zstd, Guile-zstd}, for zstd
856 compression and decompression in @command{guix publish} and for
857 substitutes (@pxref{Invoking guix publish}).
860 @uref{https://ngyro.com/software/guile-semver.html, Guile-Semver} for
861 the @code{crate} importer (@pxref{Invoking guix import}).
864 When @url{http://www.bzip.org, libbz2} is available,
865 @command{guix-daemon} can use it to compress build logs.
868 Unless @option{--disable-daemon} was passed to @command{configure}, the
869 following packages are also needed:
872 @item @url{https://gnupg.org/, GNU libgcrypt};
873 @item @url{https://sqlite.org, SQLite 3};
874 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
878 @cindex state directory
879 When configuring Guix on a system that already has a Guix installation,
880 be sure to specify the same state directory as the existing installation
881 using the @option{--localstatedir} option of the @command{configure}
882 script (@pxref{Directory Variables, @code{localstatedir},, standards,
883 GNU Coding Standards}). Usually, this @var{localstatedir} option is
884 set to the value @file{/var}. The @command{configure} script protects
885 against unintended misconfiguration of @var{localstatedir} so you do not
886 inadvertently corrupt your store (@pxref{The Store}).
888 @node Running the Test Suite
889 @section Running the Test Suite
892 After a successful @command{configure} and @code{make} run, it is a good
893 idea to run the test suite. It can help catch issues with the setup or
894 environment, or bugs in Guix itself---and really, reporting test
895 failures is a good way to help improve the software. To run the test
902 Test cases can run in parallel: you can use the @code{-j} option of
903 GNU@tie{}make to speed things up. The first run may take a few minutes
904 on a recent machine; subsequent runs will be faster because the store
905 that is created for test purposes will already have various things in
908 It is also possible to run a subset of the tests by defining the
909 @code{TESTS} makefile variable as in this example:
912 make check TESTS="tests/store.scm tests/cpio.scm"
915 By default, tests results are displayed at a file level. In order to
916 see the details of every individual test cases, it is possible to define
917 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
920 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
923 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
924 @file{test-suite.log} file. Please specify the Guix version being used
925 as well as version numbers of the dependencies (@pxref{Requirements}) in
928 Guix also comes with a whole-system test suite that tests complete
929 Guix System instances. It can only run on systems where
930 Guix is already installed, using:
937 or, again, by defining @code{TESTS} to select a subset of tests to run:
940 make check-system TESTS="basic mcron"
943 These system tests are defined in the @code{(gnu tests @dots{})}
944 modules. They work by running the operating systems under test with
945 lightweight instrumentation in a virtual machine (VM). They can be
946 computationally intensive or rather cheap, depending on whether
947 substitutes are available for their dependencies (@pxref{Substitutes}).
948 Some of them require a lot of storage space to hold VM images.
950 Again in case of test failures, please send @email{bug-guix@@gnu.org}
953 @node Setting Up the Daemon
954 @section Setting Up the Daemon
957 Operations such as building a package or running the garbage collector
958 are all performed by a specialized process, the @dfn{build daemon}, on
959 behalf of clients. Only the daemon may access the store and its
960 associated database. Thus, any operation that manipulates the store
961 goes through the daemon. For instance, command-line tools such as
962 @command{guix package} and @command{guix build} communicate with the
963 daemon (@i{via} remote procedure calls) to instruct it what to do.
965 The following sections explain how to prepare the build daemon's
966 environment. See also @ref{Substitutes}, for information on how to allow
967 the daemon to download pre-built binaries.
970 * Build Environment Setup:: Preparing the isolated build environment.
971 * Daemon Offload Setup:: Offloading builds to remote machines.
972 * SELinux Support:: Using an SELinux policy for the daemon.
975 @node Build Environment Setup
976 @subsection Build Environment Setup
978 @cindex build environment
979 In a standard multi-user setup, Guix and its daemon---the
980 @command{guix-daemon} program---are installed by the system
981 administrator; @file{/gnu/store} is owned by @code{root} and
982 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
983 Guix tools to build packages or otherwise access the store, and the
984 daemon will do it on their behalf, ensuring that the store is kept in a
985 consistent state, and allowing built packages to be shared among users.
988 When @command{guix-daemon} runs as @code{root}, you may not want package
989 build processes themselves to run as @code{root} too, for obvious
990 security reasons. To avoid that, a special pool of @dfn{build users}
991 should be created for use by build processes started by the daemon.
992 These build users need not have a shell and a home directory: they will
993 just be used when the daemon drops @code{root} privileges in build
994 processes. Having several such users allows the daemon to launch
995 distinct build processes under separate UIDs, which guarantees that they
996 do not interfere with each other---an essential feature since builds are
997 regarded as pure functions (@pxref{Introduction}).
999 On a GNU/Linux system, a build user pool may be created like this (using
1000 Bash syntax and the @code{shadow} commands):
1002 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
1003 @c for why `-G' is needed.
1005 # groupadd --system guixbuild
1006 # for i in `seq -w 1 10`;
1008 useradd -g guixbuild -G guixbuild \
1009 -d /var/empty -s `which nologin` \
1010 -c "Guix build user $i" --system \
1016 The number of build users determines how many build jobs may run in
1017 parallel, as specified by the @option{--max-jobs} option
1018 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
1019 @command{guix system vm} and related commands, you may need to add the
1020 build users to the @code{kvm} group so they can access @file{/dev/kvm},
1021 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
1022 (@pxref{Invoking guix system}).
1024 The @code{guix-daemon} program may then be run as @code{root} with the
1025 following command@footnote{If your machine uses the systemd init system,
1026 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
1027 file in @file{/etc/systemd/system} will ensure that
1028 @command{guix-daemon} is automatically started. Similarly, if your
1029 machine uses the Upstart init system, drop the
1030 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
1031 file in @file{/etc/init}.}:
1034 # guix-daemon --build-users-group=guixbuild
1039 This way, the daemon starts build processes in a chroot, under one of
1040 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
1041 environment contains nothing but:
1043 @c Keep this list in sync with libstore/build.cc! -----------------------
1046 a minimal @code{/dev} directory, created mostly independently from the
1047 host @code{/dev}@footnote{``Mostly'', because while the set of files
1048 that appear in the chroot's @code{/dev} is fixed, most of these files
1049 can only be created if the host has them.};
1052 the @code{/proc} directory; it only shows the processes of the container
1053 since a separate PID name space is used;
1056 @file{/etc/passwd} with an entry for the current user and an entry for
1060 @file{/etc/group} with an entry for the user's group;
1063 @file{/etc/hosts} with an entry that maps @code{localhost} to
1067 a writable @file{/tmp} directory.
1070 You can influence the directory where the daemon stores build trees
1071 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1072 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1073 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1074 This way, the value of @env{TMPDIR} does not leak inside build
1075 environments, which avoids discrepancies in cases where build processes
1076 capture the name of their build tree.
1080 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1081 environment variables for HTTP and HTTPS downloads it performs, be it
1082 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1083 (@pxref{Substitutes}).
1085 If you are installing Guix as an unprivileged user, it is still possible
1086 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1087 However, build processes will not be isolated from one another, and not
1088 from the rest of the system. Thus, build processes may interfere with
1089 each other, and may access programs, libraries, and other files
1090 available on the system---making it much harder to view them as
1091 @emph{pure} functions.
1094 @node Daemon Offload Setup
1095 @subsection Using the Offload Facility
1099 When desired, the build daemon can @dfn{offload} derivation builds to
1100 other machines running Guix, using the @code{offload} @dfn{build
1101 hook}@footnote{This feature is available only when
1102 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1103 present.}. When that feature is enabled, a list of user-specified build
1104 machines is read from @file{/etc/guix/machines.scm}; every time a build
1105 is requested, for instance via @code{guix build}, the daemon attempts to
1106 offload it to one of the machines that satisfy the constraints of the
1107 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1108 A single machine can have multiple system types, either because its
1109 architecture natively supports it, via emulation
1110 (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
1111 or both. Missing prerequisites for the build are
1112 copied over SSH to the target machine, which then proceeds with the
1113 build; upon success the output(s) of the build are copied back to the
1114 initial machine. The offload facility comes with a basic scheduler that
1115 attempts to select the best machine. The best machine is chosen among
1116 the available machines based on criteria such as:
1120 The availability of a build slot. A build machine can have as many
1121 build slots (connections) as the value of the @code{parallel-builds}
1122 field of its @code{build-machine} object.
1125 Its relative speed, as defined via the @code{speed} field of its
1126 @code{build-machine} object.
1129 Its load. The normalized machine load must be lower than a threshold
1130 value, configurable via the @code{overload-threshold} field of its
1131 @code{build-machine} object.
1134 Disk space availability. More than a 100 MiB must be available.
1137 The @file{/etc/guix/machines.scm} file typically looks like this:
1140 (list (build-machine
1141 (name "eightysix.example.org")
1142 (systems (list "x86_64-linux" "i686-linux"))
1143 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1145 (speed 2.)) ;incredibly fast!
1148 (name "armeight.example.org")
1149 (systems (list "aarch64-linux"))
1150 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1153 (string-append (getenv "HOME")
1154 "/.ssh/identity-for-guix"))))
1158 In the example above we specify a list of two build machines, one for
1159 the @code{x86_64} and @code{i686} architectures and one for the
1160 @code{aarch64} architecture.
1162 In fact, this file is---not surprisingly!---a Scheme file that is
1163 evaluated when the @code{offload} hook is started. Its return value
1164 must be a list of @code{build-machine} objects. While this example
1165 shows a fixed list of build machines, one could imagine, say, using
1166 DNS-SD to return a list of potential build machines discovered in the
1167 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1168 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1171 @deftp {Data Type} build-machine
1172 This data type represents build machines to which the daemon may offload
1173 builds. The important fields are:
1178 The host name of the remote machine.
1181 The system types the remote machine supports---e.g., @code{(list
1182 "x86_64-linux" "i686-linux")}.
1185 The user account to use when connecting to the remote machine over SSH.
1186 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1187 allow non-interactive logins.
1190 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1191 This is used to authenticate the machine when we connect to it. It is a
1192 long string that looks like this:
1195 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1198 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1199 key can be found in a file such as
1200 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1202 If the machine is running the SSH daemon of GNU@tie{}lsh,
1203 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1204 similar file. It can be converted to the OpenSSH format using
1205 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1208 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1209 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1214 A number of optional fields may be specified:
1218 @item @code{port} (default: @code{22})
1219 Port number of SSH server on the machine.
1221 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1222 The SSH private key file to use when connecting to the machine, in
1223 OpenSSH format. This key must not be protected with a passphrase.
1225 Note that the default value is the private key @emph{of the root
1226 account}. Make sure it exists if you use the default.
1228 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1229 @itemx @code{compression-level} (default: @code{3})
1230 The SSH-level compression methods and compression level requested.
1232 Note that offloading relies on SSH compression to reduce bandwidth usage
1233 when transferring files to and from build machines.
1235 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1236 File name of the Unix-domain socket @command{guix-daemon} is listening
1239 @item @code{overload-threshold} (default: @code{0.6})
1240 The load threshold above which a potential offload machine is
1241 disregarded by the offload scheduler. The value roughly translates to
1242 the total processor usage of the build machine, ranging from 0.0 (0%) to
1243 1.0 (100%). It can also be disabled by setting
1244 @code{overload-threshold} to @code{#f}.
1246 @item @code{parallel-builds} (default: @code{1})
1247 The number of builds that may run in parallel on the machine.
1249 @item @code{speed} (default: @code{1.0})
1250 A ``relative speed factor''. The offload scheduler will tend to prefer
1251 machines with a higher speed factor.
1253 @item @code{features} (default: @code{'()})
1254 A list of strings denoting specific features supported by the machine.
1255 An example is @code{"kvm"} for machines that have the KVM Linux modules
1256 and corresponding hardware support. Derivations can request features by
1257 name, and they will be scheduled on matching build machines.
1262 The @command{guix} command must be in the search path on the build
1263 machines. You can check whether this is the case by running:
1266 ssh build-machine guix repl --version
1269 There is one last thing to do once @file{machines.scm} is in place. As
1270 explained above, when offloading, files are transferred back and forth
1271 between the machine stores. For this to work, you first need to
1272 generate a key pair on each machine to allow the daemon to export signed
1273 archives of files from the store (@pxref{Invoking guix archive}):
1276 # guix archive --generate-key
1280 Each build machine must authorize the key of the master machine so that
1281 it accepts store items it receives from the master:
1284 # guix archive --authorize < master-public-key.txt
1288 Likewise, the master machine must authorize the key of each build machine.
1290 All the fuss with keys is here to express pairwise mutual trust
1291 relations between the master and the build machines. Concretely, when
1292 the master receives files from a build machine (and @i{vice versa}), its
1293 build daemon can make sure they are genuine, have not been tampered
1294 with, and that they are signed by an authorized key.
1296 @cindex offload test
1297 To test whether your setup is operational, run this command on the
1304 This will attempt to connect to each of the build machines specified in
1305 @file{/etc/guix/machines.scm}, make sure Guix is
1306 available on each machine, attempt to export to the machine and import
1307 from it, and report any error in the process.
1309 If you want to test a different machine file, just specify it on the
1313 # guix offload test machines-qualif.scm
1316 Last, you can test the subset of the machines whose name matches a
1317 regular expression like this:
1320 # guix offload test machines.scm '\.gnu\.org$'
1323 @cindex offload status
1324 To display the current load of all build hosts, run this command on the
1328 # guix offload status
1332 @node SELinux Support
1333 @subsection SELinux Support
1335 @cindex SELinux, daemon policy
1336 @cindex mandatory access control, SELinux
1337 @cindex security, guix-daemon
1338 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1339 can be installed on a system where SELinux is enabled, in order to label
1340 Guix files and to specify the expected behavior of the daemon. Since
1341 Guix System does not provide an SELinux base policy, the daemon policy cannot
1342 be used on Guix System.
1344 @subsubsection Installing the SELinux policy
1345 @cindex SELinux, policy installation
1346 To install the policy run this command as root:
1349 semodule -i etc/guix-daemon.cil
1352 Then relabel the file system with @code{restorecon} or by a different
1353 mechanism provided by your system.
1355 Once the policy is installed, the file system has been relabeled, and
1356 the daemon has been restarted, it should be running in the
1357 @code{guix_daemon_t} context. You can confirm this with the following
1361 ps -Zax | grep guix-daemon
1364 Monitor the SELinux log files as you run a command like @code{guix build
1365 hello} to convince yourself that SELinux permits all necessary
1368 @subsubsection Limitations
1369 @cindex SELinux, limitations
1371 This policy is not perfect. Here is a list of limitations or quirks
1372 that should be considered when deploying the provided SELinux policy for
1377 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1378 operations involve contexts that have anything to do with
1379 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1380 but it would be preferrable to define socket rules for only this label.
1383 @code{guix gc} cannot access arbitrary links to profiles. By design,
1384 the file label of the destination of a symlink is independent of the
1385 file label of the link itself. Although all profiles under
1386 $localstatedir are labelled, the links to these profiles inherit the
1387 label of the directory they are in. For links in the user’s home
1388 directory this will be @code{user_home_t}. But for links from the root
1389 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1390 directory, etc, this won’t work. @code{guix gc} would be prevented from
1391 reading and following these links.
1394 The daemon’s feature to listen for TCP connections might no longer work.
1395 This might require extra rules, because SELinux treats network sockets
1396 differently from files.
1399 Currently all files with a name matching the regular expression
1400 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1401 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1402 that name in any profile would be permitted to run in the
1403 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1404 build a package that provides this executable and convince a user to
1405 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1406 At that point SELinux could not prevent it from accessing files that are
1407 allowed for processes in that domain.
1409 You will need to relabel the store directory after all upgrades to
1410 @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
1411 store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
1412 or by other means provided by your operating system.
1414 We could generate a much more restrictive policy at installation time,
1415 so that only the @emph{exact} file name of the currently installed
1416 @code{guix-daemon} executable would be labelled with
1417 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1418 The downside is that root would have to install or upgrade the policy at
1419 installation time whenever the Guix package that provides the
1420 effectively running @code{guix-daemon} executable is upgraded.
1423 @node Invoking guix-daemon
1424 @section Invoking @command{guix-daemon}
1426 The @command{guix-daemon} program implements all the functionality to
1427 access the store. This includes launching build processes, running the
1428 garbage collector, querying the availability of a build result, etc. It
1429 is normally run as @code{root} like this:
1432 # guix-daemon --build-users-group=guixbuild
1436 For details on how to set it up, @pxref{Setting Up the Daemon}.
1439 @cindex container, build environment
1440 @cindex build environment
1441 @cindex reproducible builds
1442 By default, @command{guix-daemon} launches build processes under
1443 different UIDs, taken from the build group specified with
1444 @option{--build-users-group}. In addition, each build process is run in a
1445 chroot environment that only contains the subset of the store that the
1446 build process depends on, as specified by its derivation
1447 (@pxref{Programming Interface, derivation}), plus a set of specific
1448 system directories. By default, the latter contains @file{/dev} and
1449 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1450 @dfn{container}: in addition to having its own file system tree, it has
1451 a separate mount name space, its own PID name space, network name space,
1452 etc. This helps achieve reproducible builds (@pxref{Features}).
1454 When the daemon performs a build on behalf of the user, it creates a
1455 build directory under @file{/tmp} or under the directory specified by
1456 its @env{TMPDIR} environment variable. This directory is shared with
1457 the container for the duration of the build, though within the container,
1458 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1460 The build directory is automatically deleted upon completion, unless the
1461 build failed and the client specified @option{--keep-failed}
1462 (@pxref{Invoking guix build, @option{--keep-failed}}).
1464 The daemon listens for connections and spawns one sub-process for each session
1465 started by a client (one of the @command{guix} sub-commands). The
1466 @command{guix processes} command allows you to get an overview of the activity
1467 on your system by viewing each of the active sessions and clients.
1468 @xref{Invoking guix processes}, for more information.
1470 The following command-line options are supported:
1473 @item --build-users-group=@var{group}
1474 Take users from @var{group} to run build processes (@pxref{Setting Up
1475 the Daemon, build users}).
1477 @item --no-substitutes
1479 Do not use substitutes for build products. That is, always build things
1480 locally instead of allowing downloads of pre-built binaries
1481 (@pxref{Substitutes}).
1483 When the daemon runs with @option{--no-substitutes}, clients can still
1484 explicitly enable substitution @i{via} the @code{set-build-options}
1485 remote procedure call (@pxref{The Store}).
1487 @anchor{daemon-substitute-urls}
1488 @item --substitute-urls=@var{urls}
1489 Consider @var{urls} the default whitespace-separated list of substitute
1490 source URLs. When this option is omitted,
1491 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1493 This means that substitutes may be downloaded from @var{urls}, as long
1494 as they are signed by a trusted signature (@pxref{Substitutes}).
1496 @xref{Getting Substitutes from Other Servers}, for more information on
1497 how to configure the daemon to get substitutes from other servers.
1501 Do not use offload builds to other machines (@pxref{Daemon Offload
1502 Setup}). That is, always build things locally instead of offloading
1503 builds to remote machines.
1505 @item --cache-failures
1506 Cache build failures. By default, only successful builds are cached.
1508 When this option is used, @command{guix gc --list-failures} can be used
1509 to query the set of store items marked as failed; @command{guix gc
1510 --clear-failures} removes store items from the set of cached failures.
1511 @xref{Invoking guix gc}.
1513 @item --cores=@var{n}
1515 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1518 The default value is @code{0}, but it may be overridden by clients, such
1519 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1522 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1523 in the build process, which can then use it to exploit internal
1524 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1526 @item --max-jobs=@var{n}
1528 Allow at most @var{n} build jobs in parallel. The default value is
1529 @code{1}. Setting it to @code{0} means that no builds will be performed
1530 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1531 Setup}), or simply fail.
1533 @item --max-silent-time=@var{seconds}
1534 When the build or substitution process remains silent for more than
1535 @var{seconds}, terminate it and report a build failure.
1537 The default value is @code{0}, which disables the timeout.
1539 The value specified here can be overridden by clients (@pxref{Common
1540 Build Options, @option{--max-silent-time}}).
1542 @item --timeout=@var{seconds}
1543 Likewise, when the build or substitution process lasts for more than
1544 @var{seconds}, terminate it and report a build failure.
1546 The default value is @code{0}, which disables the timeout.
1548 The value specified here can be overridden by clients (@pxref{Common
1549 Build Options, @option{--timeout}}).
1551 @item --rounds=@var{N}
1552 Build each derivation @var{n} times in a row, and raise an error if
1553 consecutive build results are not bit-for-bit identical. Note that this
1554 setting can be overridden by clients such as @command{guix build}
1555 (@pxref{Invoking guix build}).
1557 When used in conjunction with @option{--keep-failed}, the differing
1558 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1559 This makes it easy to look for differences between the two results.
1562 Produce debugging output.
1564 This is useful to debug daemon start-up issues, but then it may be
1565 overridden by clients, for example the @option{--verbosity} option of
1566 @command{guix build} (@pxref{Invoking guix build}).
1568 @item --chroot-directory=@var{dir}
1569 Add @var{dir} to the build chroot.
1571 Doing this may change the result of build processes---for instance if
1572 they use optional dependencies found in @var{dir} when it is available,
1573 and not otherwise. For that reason, it is not recommended to do so.
1574 Instead, make sure that each derivation declares all the inputs that it
1577 @item --disable-chroot
1578 Disable chroot builds.
1580 Using this option is not recommended since, again, it would allow build
1581 processes to gain access to undeclared dependencies. It is necessary,
1582 though, when @command{guix-daemon} is running under an unprivileged user
1585 @item --log-compression=@var{type}
1586 Compress build logs according to @var{type}, one of @code{gzip},
1587 @code{bzip2}, or @code{none}.
1589 Unless @option{--lose-logs} is used, all the build logs are kept in the
1590 @var{localstatedir}. To save space, the daemon automatically compresses
1591 them with Bzip2 by default.
1593 @item --discover[=yes|no]
1594 Whether to discover substitute servers on the local network using mDNS
1597 This feature is still experimental. However, here are a few
1602 It might be faster/less expensive than fetching from remote servers;
1604 There are no security risks, only genuine substitutes will be used
1605 (@pxref{Substitute Authentication});
1607 An attacker advertising @command{guix publish} on your LAN cannot serve
1608 you malicious binaries, but they can learn what software you’re
1611 Servers may serve substitute over HTTP, unencrypted, so anyone on the
1612 LAN can see what software you’re installing.
1615 It is also possible to enable or disable substitute server discovery at
1616 run-time by running:
1619 herd discover guix-daemon on
1620 herd discover guix-daemon off
1623 @item --disable-deduplication
1624 @cindex deduplication
1625 Disable automatic file ``deduplication'' in the store.
1627 By default, files added to the store are automatically ``deduplicated'':
1628 if a newly added file is identical to another one found in the store,
1629 the daemon makes the new file a hard link to the other file. This can
1630 noticeably reduce disk usage, at the expense of slightly increased
1631 input/output load at the end of a build process. This option disables
1634 @item --gc-keep-outputs[=yes|no]
1635 Tell whether the garbage collector (GC) must keep outputs of live
1639 @cindex garbage collector roots
1640 When set to @code{yes}, the GC will keep the outputs of any live
1641 derivation available in the store---the @file{.drv} files. The default
1642 is @code{no}, meaning that derivation outputs are kept only if they are
1643 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1646 @item --gc-keep-derivations[=yes|no]
1647 Tell whether the garbage collector (GC) must keep derivations
1648 corresponding to live outputs.
1650 When set to @code{yes}, as is the case by default, the GC keeps
1651 derivations---i.e., @file{.drv} files---as long as at least one of their
1652 outputs is live. This allows users to keep track of the origins of
1653 items in their store. Setting it to @code{no} saves a bit of disk
1656 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1657 liveness to flow from outputs to derivations, and setting
1658 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1659 derivations to outputs. When both are set to @code{yes}, the effect is
1660 to keep all the build prerequisites (the sources, compiler, libraries,
1661 and other build-time tools) of live objects in the store, regardless of
1662 whether these prerequisites are reachable from a GC root. This is
1663 convenient for developers since it saves rebuilds or downloads.
1665 @item --impersonate-linux-2.6
1666 On Linux-based systems, impersonate Linux 2.6. This means that the
1667 kernel's @command{uname} system call will report 2.6 as the release number.
1669 This might be helpful to build programs that (usually wrongfully) depend
1670 on the kernel version number.
1673 Do not keep build logs. By default they are kept under
1674 @file{@var{localstatedir}/guix/log}.
1676 @item --system=@var{system}
1677 Assume @var{system} as the current system type. By default it is the
1678 architecture/kernel pair found at configure time, such as
1679 @code{x86_64-linux}.
1681 @item --listen=@var{endpoint}
1682 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1683 as the file name of a Unix-domain socket if it starts with
1684 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1685 host name or host name and port to listen to. Here are a few examples:
1688 @item --listen=/gnu/var/daemon
1689 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1690 creating it if needed.
1692 @item --listen=localhost
1693 @cindex daemon, remote access
1694 @cindex remote access to the daemon
1695 @cindex daemon, cluster setup
1696 @cindex clusters, daemon setup
1697 Listen for TCP connections on the network interface corresponding to
1698 @code{localhost}, on port 44146.
1700 @item --listen=128.0.0.42:1234
1701 Listen for TCP connections on the network interface corresponding to
1702 @code{128.0.0.42}, on port 1234.
1705 This option can be repeated multiple times, in which case
1706 @command{guix-daemon} accepts connections on all the specified
1707 endpoints. Users can tell client commands what endpoint to connect to
1708 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1709 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1712 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1713 @option{--listen=@var{host}} is suitable on local networks, such as
1714 clusters, where only trusted nodes may connect to the build daemon. In
1715 other cases where remote access to the daemon is needed, we recommend
1716 using Unix-domain sockets along with SSH.
1719 When @option{--listen} is omitted, @command{guix-daemon} listens for
1720 connections on the Unix-domain socket located at
1721 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1725 @node Application Setup
1726 @section Application Setup
1728 @cindex foreign distro
1729 When using Guix on top of GNU/Linux distribution other than Guix System---a
1730 so-called @dfn{foreign distro}---a few additional steps are needed to
1731 get everything in place. Here are some of them.
1735 @anchor{locales-and-locpath}
1736 @cindex locales, when not on Guix System
1738 @vindex GUIX_LOCPATH
1739 Packages installed @i{via} Guix will not use the locale data of the
1740 host system. Instead, you must first install one of the locale packages
1741 available with Guix and then define the @env{GUIX_LOCPATH} environment
1745 $ guix install glibc-locales
1746 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1749 Note that the @code{glibc-locales} package contains data for all the
1750 locales supported by the GNU@tie{}libc and weighs in at around
1751 917@tie{}MiB. Alternatively, the @code{glibc-utf8-locales} is smaller but
1752 limited to a few UTF-8 locales.
1754 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1755 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1756 Manual}). There are two important differences though:
1760 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1761 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1762 to make sure the programs of the foreign distro will not end up loading
1763 incompatible locale data.
1766 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1767 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1768 should your Guix profile contain a mixture of programs linked against
1769 different libc version, each libc version will only try to load locale
1770 data in the right format.
1773 This is important because the locale data format used by different libc
1774 versions may be incompatible.
1776 @subsection Name Service Switch
1778 @cindex name service switch, glibc
1779 @cindex NSS (name service switch), glibc
1780 @cindex nscd (name service caching daemon)
1781 @cindex name service caching daemon (nscd)
1782 When using Guix on a foreign distro, we @emph{strongly recommend} that
1783 the system run the GNU C library's @dfn{name service cache daemon},
1784 @command{nscd}, which should be listening on the
1785 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1786 installed with Guix may fail to look up host names or user accounts, or
1787 may even crash. The next paragraphs explain why.
1789 @cindex @file{nsswitch.conf}
1790 The GNU C library implements a @dfn{name service switch} (NSS), which is
1791 an extensible mechanism for ``name lookups'' in general: host name
1792 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1793 The GNU C Library Reference Manual}).
1795 @cindex Network information service (NIS)
1796 @cindex NIS (Network information service)
1797 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1798 lookup implementations: for example, the @code{nss-mdns} plugin allow
1799 resolution of @code{.local} host names, the @code{nis} plugin allows
1800 user account lookup using the Network information service (NIS), and so
1801 on. These extra ``lookup services'' are configured system-wide in
1802 @file{/etc/nsswitch.conf}, and all the programs running on the system
1803 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1806 When they perform a name lookup---for instance by calling the
1807 @code{getaddrinfo} function in C---applications first try to connect to
1808 the nscd; on success, nscd performs name lookups on their behalf. If
1809 the nscd is not running, then they perform the name lookup by
1810 themselves, by loading the name lookup services into their own address
1811 space and running it. These name lookup services---the
1812 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1813 the host system's C library, rather than from the C library the
1814 application is linked against (the C library coming from Guix).
1816 And this is where the problem is: if your application is linked against
1817 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1818 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1819 likely crash or have its name lookups fail unexpectedly.
1821 Running @command{nscd} on the system, among other advantages, eliminates
1822 this binary incompatibility problem because those @code{libnss_*.so}
1823 files are loaded in the @command{nscd} process, not in applications
1826 @subsection X11 Fonts
1829 The majority of graphical applications use Fontconfig to locate and
1830 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1831 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1832 by default. Thus, to allow graphical applications installed with Guix
1833 to display fonts, you have to install fonts with Guix as well.
1834 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1835 @code{font-gnu-freefont}.
1837 @cindex @code{fc-cache}
1839 Once you have installed or removed fonts, or when you notice an
1840 application that does not find fonts, you may need to install Fontconfig
1841 and to force an update of its font cache by running:
1844 guix install fontconfig
1848 To display text written in Chinese languages, Japanese, or Korean in
1849 graphical applications, consider installing
1850 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1851 has multiple outputs, one per language family (@pxref{Packages with
1852 Multiple Outputs}). For instance, the following command installs fonts
1853 for Chinese languages:
1856 guix install font-adobe-source-han-sans:cn
1859 @cindex @code{xterm}
1860 Older programs such as @command{xterm} do not use Fontconfig and instead
1861 rely on server-side font rendering. Such programs require to specify a
1862 full name of a font using XLFD (X Logical Font Description), like this:
1865 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1868 To be able to use such full names for the TrueType fonts installed in
1869 your Guix profile, you need to extend the font path of the X server:
1871 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1872 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1874 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1877 @cindex @code{xlsfonts}
1878 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1879 to make sure your TrueType fonts are listed there.
1882 @subsection X.509 Certificates
1884 @cindex @code{nss-certs}
1885 The @code{nss-certs} package provides X.509 certificates, which allow
1886 programs to authenticate Web servers accessed over HTTPS.
1888 When using Guix on a foreign distro, you can install this package and
1889 define the relevant environment variables so that packages know where to
1890 look for certificates. @xref{X.509 Certificates}, for detailed
1893 @subsection Emacs Packages
1895 @cindex @code{emacs}
1896 When you install Emacs packages with Guix, the Elisp files are placed
1897 under the @file{share/emacs/site-lisp/} directory of the profile in
1898 which they are installed. The Elisp libraries are made available to
1899 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1900 set when installing Emacs itself.
1902 Additionally, autoload definitions are automatically evaluated at the
1903 initialization of Emacs, by the Guix-specific
1904 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1905 want to avoid auto-loading the Emacs packages installed with Guix, you
1906 can do so by running Emacs with the @option{--no-site-file} option
1907 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1910 @node Upgrading Guix
1911 @section Upgrading Guix
1913 @cindex Upgrading Guix, on a foreign distro
1915 To upgrade Guix, run:
1921 @xref{Invoking guix pull}, for more information.
1923 @cindex upgrading Guix for the root user, on a foreign distro
1924 @cindex upgrading the Guix daemon, on a foreign distro
1925 @cindex @command{guix pull} for the root user, on a foreign distro
1927 On a foreign distro, you can upgrade the build daemon by running:
1934 followed by (assuming your distro uses the systemd service management
1938 systemctl restart guix-daemon.service
1941 On Guix System, upgrading the daemon is achieved by reconfiguring the
1942 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1946 @c *********************************************************************
1947 @node System Installation
1948 @chapter System Installation
1950 @cindex installing Guix System
1951 @cindex Guix System, installation
1952 This section explains how to install Guix System
1953 on a machine. Guix, as a package manager, can
1954 also be installed on top of a running GNU/Linux system,
1955 @pxref{Installation}.
1959 @c This paragraph is for people reading this from tty2 of the
1960 @c installation image.
1961 You are reading this documentation with an Info reader. For details on
1962 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
1963 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
1964 Info}. Hit @kbd{l} afterwards to come back here.
1966 Alternatively, run @command{info info} in another tty to keep the manual
1972 * Limitations:: What you can expect.
1973 * Hardware Considerations:: Supported hardware.
1974 * USB Stick and DVD Installation:: Preparing the installation medium.
1975 * Preparing for Installation:: Networking, partitioning, etc.
1976 * Guided Graphical Installation:: Easy graphical installation.
1977 * Manual Installation:: Manual installation for wizards.
1978 * After System Installation:: When installation succeeded.
1979 * Installing Guix in a VM:: Guix System playground.
1980 * Building the Installation Image:: How this comes to be.
1984 @section Limitations
1986 We consider Guix System to be ready for a wide range of ``desktop'' and server
1987 use cases. The reliability guarantees it provides---transactional upgrades
1988 and rollbacks, reproducibility---make it a solid foundation.
1990 Nevertheless, before you proceed with the installation, be aware of the
1991 following noteworthy limitations applicable to version @value{VERSION}:
1995 More and more system services are provided (@pxref{Services}), but some
1999 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
2000 as well as a number of X11 window managers. However, KDE is currently
2004 More than a disclaimer, this is an invitation to report issues (and success
2005 stories!), and to join us in improving it. @xref{Contributing}, for more
2009 @node Hardware Considerations
2010 @section Hardware Considerations
2012 @cindex hardware support on Guix System
2013 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
2014 builds around the kernel Linux-libre, which means that only hardware for
2015 which free software drivers and firmware exist is supported. Nowadays,
2016 a wide range of off-the-shelf hardware is supported on
2017 GNU/Linux-libre---from keyboards to graphics cards to scanners and
2018 Ethernet controllers. Unfortunately, there are still areas where
2019 hardware vendors deny users control over their own computing, and such
2020 hardware is not supported on Guix System.
2022 @cindex WiFi, hardware support
2023 One of the main areas where free drivers or firmware are lacking is WiFi
2024 devices. WiFi devices known to work include those using Atheros chips
2025 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
2026 driver, and those using Broadcom/AirForce chips (BCM43xx with
2027 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
2028 Linux-libre driver. Free firmware exists for both and is available
2029 out-of-the-box on Guix System, as part of @code{%base-firmware}
2030 (@pxref{operating-system Reference, @code{firmware}}).
2032 @cindex RYF, Respects Your Freedom
2033 The @uref{https://www.fsf.org/, Free Software Foundation} runs
2034 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
2035 certification program for hardware products that respect your freedom
2036 and your privacy and ensure that you have control over your device. We
2037 encourage you to check the list of RYF-certified devices.
2039 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
2040 web site. It contains a catalog of hardware devices with information
2041 about their support in GNU/Linux.
2044 @node USB Stick and DVD Installation
2045 @section USB Stick and DVD Installation
2047 An ISO-9660 installation image that can be written to a USB stick or
2048 burnt to a DVD can be downloaded from
2049 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
2050 where you can replace @code{x86_64-linux} with one of:
2054 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
2057 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
2060 @c start duplication of authentication part from ``Binary Installation''
2061 Make sure to download the associated @file{.sig} file and to verify the
2062 authenticity of the image against it, along these lines:
2065 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2066 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2069 If that command fails because you do not have the required public key,
2070 then run this command to import it:
2073 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
2074 -qO - | gpg --import -
2078 and rerun the @code{gpg --verify} command.
2080 Take note that a warning like ``This key is not certified with a trusted
2081 signature!'' is normal.
2085 This image contains the tools necessary for an installation.
2086 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
2088 @unnumberedsubsec Copying to a USB Stick
2090 To copy the image to a USB stick, follow these steps:
2094 Decompress the image using the @command{xz} command:
2097 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2101 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
2102 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
2103 copy the image with:
2106 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
2110 Access to @file{/dev/sdX} usually requires root privileges.
2113 @unnumberedsubsec Burning on a DVD
2115 To copy the image to a DVD, follow these steps:
2119 Decompress the image using the @command{xz} command:
2122 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2126 Insert a blank DVD into your machine, and determine
2127 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2128 copy the image with:
2131 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2134 Access to @file{/dev/srX} usually requires root privileges.
2137 @unnumberedsubsec Booting
2139 Once this is done, you should be able to reboot the system and boot from
2140 the USB stick or DVD. The latter usually requires you to get in the
2141 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2142 In order to boot from Libreboot, switch to the command mode by pressing
2143 the @kbd{c} key and type @command{search_grub usb}.
2145 @xref{Installing Guix in a VM}, if, instead, you would like to install
2146 Guix System in a virtual machine (VM).
2149 @node Preparing for Installation
2150 @section Preparing for Installation
2152 Once you have booted, you can use the guided graphical installer, which makes
2153 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2154 if you are already familiar with GNU/Linux and if you want more control than
2155 what the graphical installer provides, you can choose the ``manual''
2156 installation process (@pxref{Manual Installation}).
2158 The graphical installer is available on TTY1. You can obtain root shells on
2159 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2160 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2161 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2162 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2163 which allows you to select text with the left mouse button and to paste it
2164 with the middle button.
2167 Installation requires access to the Internet so that any missing
2168 dependencies of your system configuration can be downloaded. See the
2169 ``Networking'' section below.
2172 @node Guided Graphical Installation
2173 @section Guided Graphical Installation
2175 The graphical installer is a text-based user interface. It will guide you,
2176 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2178 The first dialog boxes allow you to set up the system as you use it during the
2179 installation: you can choose the language, keyboard layout, and set up
2180 networking, which will be used during the installation. The image below shows
2181 the networking dialog.
2183 @image{images/installer-network,5in,, networking setup with the graphical installer}
2185 Later steps allow you to partition your hard disk, as shown in the image
2186 below, to choose whether or not to use encrypted file systems, to enter the
2187 host name and root password, and to create an additional account, among other
2190 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2192 Note that, at any time, the installer allows you to exit the current
2193 installation step and resume at a previous step, as show in the image below.
2195 @image{images/installer-resume,5in,, resuming the installation process}
2197 Once you're done, the installer produces an operating system configuration and
2198 displays it (@pxref{Using the Configuration System}). At that point you can
2199 hit ``OK'' and installation will proceed. On success, you can reboot into the
2200 new system and enjoy. @xref{After System Installation}, for what's next!
2203 @node Manual Installation
2204 @section Manual Installation
2206 This section describes how you would ``manually'' install GNU@tie{}Guix System
2207 on your machine. This option requires familiarity with GNU/Linux, with the
2208 shell, and with common administration tools. If you think this is not for
2209 you, consider using the guided graphical installer (@pxref{Guided Graphical
2212 The installation system provides root shells on TTYs 3 to 6; press
2213 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2214 many common tools needed to install the system. But it is also a full-blown
2215 Guix System, which means that you can install additional packages, should you
2216 need it, using @command{guix package} (@pxref{Invoking guix package}).
2219 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2220 * Proceeding with the Installation:: Installing.
2223 @node Keyboard Layout and Networking and Partitioning
2224 @subsection Keyboard Layout, Networking, and Partitioning
2226 Before you can install the system, you may want to adjust the keyboard layout,
2227 set up networking, and partition your target hard disk. This section will
2228 guide you through this.
2230 @subsubsection Keyboard Layout
2232 @cindex keyboard layout
2233 The installation image uses the US qwerty keyboard layout. If you want
2234 to change it, you can use the @command{loadkeys} command. For example,
2235 the following command selects the Dvorak keyboard layout:
2241 See the files under @file{/run/current-system/profile/share/keymaps} for
2242 a list of available keyboard layouts. Run @command{man loadkeys} for
2245 @subsubsection Networking
2247 Run the following command to see what your network interfaces are called:
2254 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2260 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2261 Wired interfaces have a name starting with @samp{e}; for example, the
2262 interface corresponding to the first on-board Ethernet controller is
2263 called @samp{eno1}. Wireless interfaces have a name starting with
2264 @samp{w}, like @samp{w1p2s0}.
2267 @item Wired connection
2268 To configure a wired network run the following command, substituting
2269 @var{interface} with the name of the wired interface you want to use.
2272 ifconfig @var{interface} up
2276 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2279 ip link set @var{interface} up
2282 @item Wireless connection
2285 To configure wireless networking, you can create a configuration file
2286 for the @command{wpa_supplicant} configuration tool (its location is not
2287 important) using one of the available text editors such as
2291 nano wpa_supplicant.conf
2294 As an example, the following stanza can go to this file and will work
2295 for many wireless networks, provided you give the actual SSID and
2296 passphrase for the network you are connecting to:
2300 ssid="@var{my-ssid}"
2302 psk="the network's secret passphrase"
2306 Start the wireless service and run it in the background with the
2307 following command (substitute @var{interface} with the name of the
2308 network interface you want to use):
2311 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2314 Run @command{man wpa_supplicant} for more information.
2318 At this point, you need to acquire an IP address. On a network where IP
2319 addresses are automatically assigned @i{via} DHCP, you can run:
2322 dhclient -v @var{interface}
2325 Try to ping a server to see if networking is up and running:
2331 Setting up network access is almost always a requirement because the
2332 image does not contain all the software and tools that may be needed.
2334 @cindex proxy, during system installation
2335 If you need HTTP and HTTPS access to go through a proxy, run the
2339 herd set-http-proxy guix-daemon @var{URL}
2343 where @var{URL} is the proxy URL, for example
2344 @code{http://example.org:8118}.
2346 @cindex installing over SSH
2347 If you want to, you can continue the installation remotely by starting
2351 herd start ssh-daemon
2354 Make sure to either set a password with @command{passwd}, or configure
2355 OpenSSH public key authentication before logging in.
2357 @subsubsection Disk Partitioning
2359 Unless this has already been done, the next step is to partition, and
2360 then format the target partition(s).
2362 The installation image includes several partitioning tools, including
2363 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2364 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2365 the partition layout you want:
2371 If your disk uses the GUID Partition Table (GPT) format and you plan to
2372 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2373 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2376 @cindex EFI, installation
2377 @cindex UEFI, installation
2378 @cindex ESP, EFI system partition
2379 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2380 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2381 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2384 parted /dev/sda set 1 esp on
2388 @vindex grub-bootloader
2389 @vindex grub-efi-bootloader
2390 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2391 @file{/sys/firmware/efi} exists in the installation image, then you should
2392 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2393 Otherwise you should use the BIOS-based GRUB, known as
2394 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2398 Once you are done partitioning the target hard disk drive, you have to
2399 create a file system on the relevant partition(s)@footnote{Currently
2400 Guix System only supports ext4, btrfs, JFS, and F2FS file systems. In
2401 particular, code that reads file system UUIDs and labels only works for these
2402 file system types.}. For the ESP, if you have one and assuming it is
2403 @file{/dev/sda1}, run:
2406 mkfs.fat -F32 /dev/sda1
2409 For the root file system, ext4 is the most widely used format. Other
2410 file systems, such as Btrfs, support compression, which is reported to
2411 nicely complement file deduplication that the daemon performs
2412 independently of the file system (@pxref{Invoking guix-daemon,
2415 Preferably, assign file systems a label so that you can easily and
2416 reliably refer to them in @code{file-system} declarations (@pxref{File
2417 Systems}). This is typically done using the @code{-L} option of
2418 @command{mkfs.ext4} and related commands. So, assuming the target root
2419 partition lives at @file{/dev/sda2}, a file system with the label
2420 @code{my-root} can be created with:
2423 mkfs.ext4 -L my-root /dev/sda2
2426 @cindex encrypted disk
2427 If you are instead planning to encrypt the root partition, you can use
2428 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2429 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2430 @code{man cryptsetup}} for more information). Assuming you want to
2431 store the root partition on @file{/dev/sda2}, the command sequence would
2432 be along these lines:
2435 cryptsetup luksFormat /dev/sda2
2436 cryptsetup open --type luks /dev/sda2 my-partition
2437 mkfs.ext4 -L my-root /dev/mapper/my-partition
2440 Once that is done, mount the target file system under @file{/mnt}
2441 with a command like (again, assuming @code{my-root} is the label of the
2445 mount LABEL=my-root /mnt
2448 Also mount any other file systems you would like to use on the target
2449 system relative to this path. If you have opted for @file{/boot/efi} as an
2450 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2451 found by @code{guix system init} afterwards.
2453 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2454 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2455 sure to initialize them with @command{mkswap}. Assuming you have one
2456 swap partition on @file{/dev/sda3}, you would run:
2463 Alternatively, you may use a swap file. For example, assuming that in
2464 the new system you want to use the file @file{/swapfile} as a swap file,
2465 you would run@footnote{This example will work for many types of file
2466 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2467 btrfs), the required steps may be different. For details, see the
2468 manual pages for @command{mkswap} and @command{swapon}.}:
2471 # This is 10 GiB of swap space. Adjust "count" to change the size.
2472 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2473 # For security, make the file readable and writable only by root.
2474 chmod 600 /mnt/swapfile
2475 mkswap /mnt/swapfile
2476 swapon /mnt/swapfile
2479 Note that if you have encrypted the root partition and created a swap
2480 file in its file system as described above, then the encryption also
2481 protects the swap file, just like any other file in that file system.
2483 @node Proceeding with the Installation
2484 @subsection Proceeding with the Installation
2486 With the target partitions ready and the target root mounted on
2487 @file{/mnt}, we're ready to go. First, run:
2490 herd start cow-store /mnt
2493 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2494 during the installation phase are written to the target disk on @file{/mnt}
2495 rather than kept in memory. This is necessary because the first phase of
2496 the @command{guix system init} command (see below) entails downloads or
2497 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2499 Next, you have to edit a file and
2500 provide the declaration of the operating system to be installed. To
2501 that end, the installation system comes with three text editors. We
2502 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2503 supports syntax highlighting and parentheses matching; other editors
2504 include GNU Zile (an Emacs clone), and
2505 nvi (a clone of the original BSD @command{vi} editor).
2506 We strongly recommend storing that file on the target root file system, say,
2507 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2508 configuration file once you have rebooted into the newly-installed system.
2510 @xref{Using the Configuration System}, for an overview of the
2511 configuration file. The example configurations discussed in that
2512 section are available under @file{/etc/configuration} in the
2513 installation image. Thus, to get started with a system configuration
2514 providing a graphical display server (a ``desktop'' system), you can run
2515 something along these lines:
2519 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2520 # nano /mnt/etc/config.scm
2523 You should pay attention to what your configuration file contains, and
2528 Make sure the @code{bootloader-configuration} form refers to the target
2529 you want to install GRUB on. It should mention @code{grub-bootloader} if
2530 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2531 for newer UEFI systems. For legacy systems, the @code{target} field
2532 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2533 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2534 currently mounted and a @code{file-system} entry is specified in your
2538 Be sure that your file system labels match the value of their respective
2539 @code{device} fields in your @code{file-system} configuration, assuming
2540 your @code{file-system} configuration uses the @code{file-system-label}
2541 procedure in its @code{device} field.
2544 If there are encrypted or RAID partitions, make sure to add a
2545 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2548 Once you are done preparing the configuration file, the new system must
2549 be initialized (remember that the target root file system is mounted
2553 guix system init /mnt/etc/config.scm /mnt
2557 This copies all the necessary files and installs GRUB on
2558 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2559 more information, @pxref{Invoking guix system}. This command may trigger
2560 downloads or builds of missing packages, which can take some time.
2562 Once that command has completed---and hopefully succeeded!---you can run
2563 @command{reboot} and boot into the new system. The @code{root} password
2564 in the new system is initially empty; other users' passwords need to be
2565 initialized by running the @command{passwd} command as @code{root},
2566 unless your configuration specifies otherwise
2567 (@pxref{user-account-password, user account passwords}).
2568 @xref{After System Installation}, for what's next!
2571 @node After System Installation
2572 @section After System Installation
2574 Success, you've now booted into Guix System! From then on, you can update the
2575 system whenever you want by running, say:
2579 sudo guix system reconfigure /etc/config.scm
2583 This builds a new system generation with the latest packages and services
2584 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2585 your system includes the latest security updates (@pxref{Security Updates}).
2587 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2589 @cindex sudo vs. @command{guix pull}
2590 Note that @command{sudo guix} runs your user's @command{guix} command and
2591 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2592 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2594 The difference matters here, because @command{guix pull} updates
2595 the @command{guix} command and package definitions only for the user it is ran
2596 as. This means that if you choose to use @command{guix system reconfigure} in
2597 root's login shell, you'll need to @command{guix pull} separately.
2600 Now, @pxref{Getting Started}, and
2601 join us on @code{#guix} on the Freenode IRC network or on
2602 @email{guix-devel@@gnu.org} to share your experience!
2605 @node Installing Guix in a VM
2606 @section Installing Guix in a Virtual Machine
2608 @cindex virtual machine, Guix System installation
2609 @cindex virtual private server (VPS)
2610 @cindex VPS (virtual private server)
2611 If you'd like to install Guix System in a virtual machine (VM) or on a
2612 virtual private server (VPS) rather than on your beloved machine, this
2615 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2616 disk image, follow these steps:
2620 First, retrieve and decompress the Guix system installation image as
2621 described previously (@pxref{USB Stick and DVD Installation}).
2624 Create a disk image that will hold the installed system. To make a
2625 qcow2-formatted disk image, use the @command{qemu-img} command:
2628 qemu-img create -f qcow2 guix-system.img 50G
2631 The resulting file will be much smaller than 50 GB (typically less than
2632 1 MB), but it will grow as the virtualized storage device is filled up.
2635 Boot the USB installation image in an VM:
2638 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2639 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2640 -drive file=guix-system.img \
2641 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2644 @code{-enable-kvm} is optional, but significantly improves performance,
2645 @pxref{Running Guix in a VM}.
2648 You're now root in the VM, proceed with the installation process.
2649 @xref{Preparing for Installation}, and follow the instructions.
2652 Once installation is complete, you can boot the system that's on your
2653 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2656 @node Building the Installation Image
2657 @section Building the Installation Image
2659 @cindex installation image
2660 The installation image described above was built using the @command{guix
2661 system} command, specifically:
2664 guix system disk-image -t iso9660 gnu/system/install.scm
2667 Have a look at @file{gnu/system/install.scm} in the source tree,
2668 and see also @ref{Invoking guix system} for more information
2669 about the installation image.
2671 @section Building the Installation Image for ARM Boards
2673 Many ARM boards require a specific variant of the
2674 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2676 If you build a disk image and the bootloader is not available otherwise
2677 (on another boot drive etc), it's advisable to build an image that
2678 includes the bootloader, specifically:
2681 guix system disk-image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2684 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2685 board, a list of possible boards will be printed.
2687 @c *********************************************************************
2688 @node Getting Started
2689 @chapter Getting Started
2691 Presumably, you've reached this section because either you have
2692 installed Guix on top of another distribution (@pxref{Installation}), or
2693 you've installed the standalone Guix System (@pxref{System
2694 Installation}). It's time for you to get started using Guix and this
2695 section aims to help you do that and give you a feel of what it's like.
2697 Guix is about installing software, so probably the first thing you'll
2698 want to do is to actually look for software. Let's say you're looking
2699 for a text editor, you can run:
2702 guix search text editor
2705 This command shows you a number of matching @dfn{packages}, each time
2706 showing the package's name, version, a description, and additional info.
2707 Once you've found out the one you want to use, let's say Emacs (ah ha!),
2708 you can go ahead and install it (run this command as a regular user,
2709 @emph{no need for root privileges}!):
2715 You've installed your first package, congrats! In the process, you've
2716 probably noticed that Guix downloaded pre-built binaries; or, if you
2717 explicitly chose to @emph{not} use pre-built binaries, then probably
2718 Guix is still building software (@pxref{Substitutes}, for more info).
2720 Unless you're using Guix System, the @command{guix install} command must
2721 have printed this hint:
2724 hint: Consider setting the necessary environment variables by running:
2726 GUIX_PROFILE="$HOME/.guix-profile"
2727 . "$GUIX_PROFILE/etc/profile"
2729 Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
2732 Indeed, you must now tell your shell where @command{emacs} and other
2733 programs installed with Guix are to be found. Pasting the two lines
2734 above will do just that: it will add
2735 @code{$HOME/.guix-profile/bin}---which is where the installed package
2736 is---to the @code{PATH} environment variable. You can paste these two
2737 lines in your shell so they take effect right away, but more importantly
2738 you should add them to @file{~/.bash_profile} (or equivalent file if you
2739 do not use Bash) so that environment variables are set next time you
2740 spawn a shell. You only need to do this once and other search paths
2741 environment variables will be taken care of similarly---e.g., if you
2742 eventually install @code{python} and Python libraries, @code{PYTHONPATH}
2745 You can go on installing packages at your will. To list installed
2749 guix package --list-installed
2752 To remove a package, you would unsurprisingly run @command{guix remove}.
2753 A distinguishing feature is the ability to @dfn{roll back} any operation
2754 you made---installation, removal, upgrade---by simply typing:
2757 guix package --roll-back
2760 This is because each operation is in fact a @dfn{transaction} that
2761 creates a new @dfn{generation}. These generations and the difference
2762 between them can be displayed by running:
2765 guix package --list-generations
2768 Now you know the basics of package management!
2770 @quotation Going further
2771 @xref{Package Management}, for more about package management. You may
2772 like @dfn{declarative} package management with @command{guix package
2773 --manifest}, managing separate @dfn{profiles} with @option{--profile},
2774 deleting old generations, collecting garbage, and other nifty features
2775 that will come in handy as you become more familiar with Guix. If you
2776 are a developer, @pxref{Development} for additional tools. And if
2777 you're curious, @pxref{Features}, to peek under the hood.
2780 Once you've installed a set of packages, you will want to periodically
2781 @emph{upgrade} them to the latest and greatest version. To do that, you
2782 will first pull the latest revision of Guix and its package collection:
2788 The end result is a new @command{guix} command, under
2789 @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
2790 first time you run @command{guix pull}, be sure to follow the hint that
2791 the command prints and, similar to what we saw above, paste these two
2792 lines in your terminal and @file{.bash_profile}:
2795 GUIX_PROFILE="$HOME/.config/guix/current"
2796 . "$GUIX_PROFILE/etc/profile"
2800 You must also instruct your shell to point to this new @command{guix}:
2806 At this point, you're running a brand new Guix. You can thus go ahead
2807 and actually upgrade all the packages you previously installed:
2813 As you run this command, you will see that binaries are downloaded (or
2814 perhaps some packages are built), and eventually you end up with the
2815 upgraded packages. Should one of these upgraded packages not be to your
2816 liking, remember you can always roll back!
2818 You can display the exact revision of Guix you're currently using by
2825 The information it displays is @emph{all it takes to reproduce the exact
2826 same Guix}, be it at a different point in time or on a different
2829 @quotation Going further
2830 @xref{Invoking guix pull}, for more information. @xref{Channels}, on
2831 how to specify additional @dfn{channels} to pull packages from, how to
2832 replicate Guix, and more. You may also find @command{time-machine}
2833 handy (@pxref{Invoking guix time-machine}).
2836 If you installed Guix System, one of the first things you'll want to do
2837 is to upgrade your system. Once you've run @command{guix pull} to get
2838 the latest Guix, you can upgrade the system like this:
2841 sudo guix system reconfigure /etc/config.scm
2844 Upon completion, the system runs the latest versions of its software
2845 packages. When you eventually reboot, you'll notice a sub-menu in the
2846 bootloader that reads ``Old system generations'': it's what allows you
2847 to boot @emph{an older generation of your system}, should the latest
2848 generation be ``broken'' or otherwise unsatisfying. Just like for
2849 packages, you can always @emph{roll back} to a previous generation
2850 @emph{of the whole system}:
2853 sudo guix system roll-back
2856 There are many things you'll probably want to tweak on your system:
2857 adding new user accounts, adding new system services, fiddling with the
2858 configuration of those services, etc. The system configuration is
2859 @emph{entirely} described in the @file{/etc/config.scm} file.
2860 @xref{Using the Configuration System}, to learn how to change it.
2862 Now you know enough to get started!
2864 @quotation Resources
2865 The rest of this manual provides a reference for all things Guix. Here
2866 are some additional resources you may find useful:
2870 @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
2871 ``how-to'' style of recipes for a variety of applications.
2874 The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
2875 Card} lists in two pages most of the commands and options you'll ever
2879 The web site contains @uref{https://guix.gnu.org/en/videos/,
2880 instructional videos} covering topics such as everyday use of Guix, how
2881 to get help, and how to become a contributor.
2884 @xref{Documentation}, to learn how to access documentation on your
2888 We hope you will enjoy Guix as much as the community enjoys building it!
2891 @c *********************************************************************
2892 @node Package Management
2893 @chapter Package Management
2896 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2897 remove software packages, without having to know about their build
2898 procedures or dependencies. Guix also goes beyond this obvious set of
2901 This chapter describes the main features of Guix, as well as the
2902 package management tools it provides. Along with the command-line
2903 interface described below (@pxref{Invoking guix package, @code{guix
2904 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2905 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2906 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2910 guix install emacs-guix
2914 * Features:: How Guix will make your life brighter.
2915 * Invoking guix package:: Package installation, removal, etc.
2916 * Substitutes:: Downloading pre-built binaries.
2917 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2918 * Invoking guix gc:: Running the garbage collector.
2919 * Invoking guix pull:: Fetching the latest Guix and distribution.
2920 * Invoking guix time-machine:: Running an older revision of Guix.
2921 * Inferiors:: Interacting with another revision of Guix.
2922 * Invoking guix describe:: Display information about your Guix revision.
2923 * Invoking guix archive:: Exporting and importing store files.
2929 Here we assume you've already made your first steps with Guix
2930 (@pxref{Getting Started}) and would like to get an overview about what's
2931 going on under the hood.
2933 When using Guix, each package ends up in the @dfn{package store}, in its
2934 own directory---something that resembles
2935 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2937 Instead of referring to these directories, users have their own
2938 @dfn{profile}, which points to the packages that they actually want to
2939 use. These profiles are stored within each user's home directory, at
2940 @code{$HOME/.guix-profile}.
2942 For example, @code{alice} installs GCC 4.7.2. As a result,
2943 @file{/home/alice/.guix-profile/bin/gcc} points to
2944 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
2945 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
2946 simply continues to point to
2947 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
2948 coexist on the same system without any interference.
2950 The @command{guix package} command is the central tool to manage
2951 packages (@pxref{Invoking guix package}). It operates on the per-user
2952 profiles, and can be used @emph{with normal user privileges}.
2954 @cindex transactions
2955 The command provides the obvious install, remove, and upgrade
2956 operations. Each invocation is actually a @emph{transaction}: either
2957 the specified operation succeeds, or nothing happens. Thus, if the
2958 @command{guix package} process is terminated during the transaction,
2959 or if a power outage occurs during the transaction, then the user's
2960 profile remains in its previous state, and remains usable.
2962 In addition, any package transaction may be @emph{rolled back}. So, if,
2963 for example, an upgrade installs a new version of a package that turns
2964 out to have a serious bug, users may roll back to the previous instance
2965 of their profile, which was known to work well. Similarly, the global
2966 system configuration on Guix is subject to
2967 transactional upgrades and roll-back
2968 (@pxref{Using the Configuration System}).
2970 All packages in the package store may be @emph{garbage-collected}.
2971 Guix can determine which packages are still referenced by user
2972 profiles, and remove those that are provably no longer referenced
2973 (@pxref{Invoking guix gc}). Users may also explicitly remove old
2974 generations of their profile so that the packages they refer to can be
2977 @cindex reproducibility
2978 @cindex reproducible builds
2979 Guix takes a @dfn{purely functional} approach to package
2980 management, as described in the introduction (@pxref{Introduction}).
2981 Each @file{/gnu/store} package directory name contains a hash of all the
2982 inputs that were used to build that package---compiler, libraries, build
2983 scripts, etc. This direct correspondence allows users to make sure a
2984 given package installation matches the current state of their
2985 distribution. It also helps maximize @dfn{build reproducibility}:
2986 thanks to the isolated build environments that are used, a given build
2987 is likely to yield bit-identical files when performed on different
2988 machines (@pxref{Invoking guix-daemon, container}).
2991 This foundation allows Guix to support @dfn{transparent binary/source
2992 deployment}. When a pre-built binary for a @file{/gnu/store} item is
2993 available from an external source---a @dfn{substitute}, Guix just
2994 downloads it and unpacks it;
2995 otherwise, it builds the package from source, locally
2996 (@pxref{Substitutes}). Because build results are usually bit-for-bit
2997 reproducible, users do not have to trust servers that provide
2998 substitutes: they can force a local build and @emph{challenge} providers
2999 (@pxref{Invoking guix challenge}).
3001 Control over the build environment is a feature that is also useful for
3002 developers. The @command{guix environment} command allows developers of
3003 a package to quickly set up the right development environment for their
3004 package, without having to manually install the dependencies of the
3005 package into their profile (@pxref{Invoking guix environment}).
3007 @cindex replication, of software environments
3008 @cindex provenance tracking, of software artifacts
3009 All of Guix and its package definitions is version-controlled, and
3010 @command{guix pull} allows you to ``travel in time'' on the history of Guix
3011 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
3012 Guix instance on a different machine or at a later point in time, which in
3013 turn allows you to @emph{replicate complete software environments}, while
3014 retaining precise @dfn{provenance tracking} of the software.
3016 @node Invoking guix package
3017 @section Invoking @command{guix package}
3019 @cindex installing packages
3020 @cindex removing packages
3021 @cindex package installation
3022 @cindex package removal
3023 The @command{guix package} command is the tool that allows users to
3024 install, upgrade, and remove packages, as well as rolling back to
3025 previous configurations. It operates only on the user's own profile,
3026 and works with normal user privileges (@pxref{Features}). Its syntax
3030 guix package @var{options}
3033 @cindex transactions
3034 Primarily, @var{options} specifies the operations to be performed during
3035 the transaction. Upon completion, a new profile is created, but
3036 previous @dfn{generations} of the profile remain available, should the user
3039 For example, to remove @code{lua} and install @code{guile} and
3040 @code{guile-cairo} in a single transaction:
3043 guix package -r lua -i guile guile-cairo
3046 @cindex aliases, for @command{guix package}
3047 For your convenience, we also provide the following aliases:
3051 @command{guix search} is an alias for @command{guix package -s},
3053 @command{guix install} is an alias for @command{guix package -i},
3055 @command{guix remove} is an alias for @command{guix package -r},
3057 @command{guix upgrade} is an alias for @command{guix package -u},
3059 and @command{guix show} is an alias for @command{guix package --show=}.
3062 These aliases are less expressive than @command{guix package} and provide
3063 fewer options, so in some cases you'll probably want to use @command{guix
3066 @command{guix package} also supports a @dfn{declarative approach}
3067 whereby the user specifies the exact set of packages to be available and
3068 passes it @i{via} the @option{--manifest} option
3069 (@pxref{profile-manifest, @option{--manifest}}).
3072 For each user, a symlink to the user's default profile is automatically
3073 created in @file{$HOME/.guix-profile}. This symlink always points to the
3074 current generation of the user's default profile. Thus, users can add
3075 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
3076 variable, and so on.
3077 @cindex search paths
3078 If you are not using Guix System, consider adding the
3079 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
3080 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
3081 shells get all the right environment variable definitions:
3084 GUIX_PROFILE="$HOME/.guix-profile" ; \
3085 source "$HOME/.guix-profile/etc/profile"
3088 In a multi-user setup, user profiles are stored in a place registered as
3089 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
3090 to (@pxref{Invoking guix gc}). That directory is normally
3091 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
3092 @var{localstatedir} is the value passed to @code{configure} as
3093 @option{--localstatedir}, and @var{user} is the user name. The
3094 @file{per-user} directory is created when @command{guix-daemon} is
3095 started, and the @var{user} sub-directory is created by @command{guix
3098 The @var{options} can be among the following:
3102 @item --install=@var{package} @dots{}
3103 @itemx -i @var{package} @dots{}
3104 Install the specified @var{package}s.
3106 Each @var{package} may specify either a simple package name, such as
3107 @code{guile}, or a package name followed by an at-sign and version number,
3108 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
3109 case, the newest version prefixed by @code{1.8} is selected).
3111 If no version number is specified, the
3112 newest available version will be selected. In addition, @var{package}
3113 may contain a colon, followed by the name of one of the outputs of the
3114 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
3115 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
3116 name (and optionally version) are searched for among the GNU
3117 distribution modules (@pxref{Package Modules}).
3119 @cindex propagated inputs
3120 Sometimes packages have @dfn{propagated inputs}: these are dependencies
3121 that automatically get installed along with the required package
3122 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
3123 @code{package} objects}, for information about propagated inputs in
3124 package definitions).
3126 @anchor{package-cmd-propagated-inputs}
3127 An example is the GNU MPC library: its C header files refer to those of
3128 the GNU MPFR library, which in turn refer to those of the GMP library.
3129 Thus, when installing MPC, the MPFR and GMP libraries also get installed
3130 in the profile; removing MPC also removes MPFR and GMP---unless they had
3131 also been explicitly installed by the user.
3133 Besides, packages sometimes rely on the definition of environment
3134 variables for their search paths (see explanation of
3135 @option{--search-paths} below). Any missing or possibly incorrect
3136 environment variable definitions are reported here.
3138 @item --install-from-expression=@var{exp}
3140 Install the package @var{exp} evaluates to.
3142 @var{exp} must be a Scheme expression that evaluates to a
3143 @code{<package>} object. This option is notably useful to disambiguate
3144 between same-named variants of a package, with expressions such as
3145 @code{(@@ (gnu packages base) guile-final)}.
3147 Note that this option installs the first output of the specified
3148 package, which may be insufficient when needing a specific output of a
3149 multiple-output package.
3151 @item --install-from-file=@var{file}
3152 @itemx -f @var{file}
3153 Install the package that the code within @var{file} evaluates to.
3155 As an example, @var{file} might contain a definition like this
3156 (@pxref{Defining Packages}):
3159 @include package-hello.scm
3162 Developers may find it useful to include such a @file{guix.scm} file
3163 in the root of their project source tree that can be used to test
3164 development snapshots and create reproducible development environments
3165 (@pxref{Invoking guix environment}).
3167 The @var{file} may also contain a JSON representation of one or more
3168 package definitions. Running @code{guix package -f} on
3169 @file{hello.json} with the following contents would result in installing
3170 the package @code{greeter} after building @code{myhello}:
3173 @verbatiminclude package-hello.json
3176 @item --remove=@var{package} @dots{}
3177 @itemx -r @var{package} @dots{}
3178 Remove the specified @var{package}s.
3180 As for @option{--install}, each @var{package} may specify a version number
3181 and/or output name in addition to the package name. For instance,
3182 @samp{-r glibc:debug} would remove the @code{debug} output of
3185 @item --upgrade[=@var{regexp} @dots{}]
3186 @itemx -u [@var{regexp} @dots{}]
3187 @cindex upgrading packages
3188 Upgrade all the installed packages. If one or more @var{regexp}s are
3189 specified, upgrade only installed packages whose name matches a
3190 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
3192 Note that this upgrades package to the latest version of packages found
3193 in the distribution currently installed. To update your distribution,
3194 you should regularly run @command{guix pull} (@pxref{Invoking guix
3197 @cindex package transformations, upgrades
3198 When upgrading, package transformations that were originally applied
3199 when creating the profile are automatically re-applied (@pxref{Package
3200 Transformation Options}). For example, assume you first installed Emacs
3201 from the tip of its development branch with:
3204 guix install emacs-next --with-branch=emacs-next=master
3207 Next time you run @command{guix upgrade}, Guix will again pull the tip
3208 of the Emacs development branch and build @code{emacs-next} from that
3211 Note that transformation options such as @option{--with-branch} and
3212 @option{--with-source} depend on external state; it is up to you to
3213 ensure that they work as expected. You can also discard a
3214 transformations that apply to a package by running:
3217 guix install @var{package}
3220 @item --do-not-upgrade[=@var{regexp} @dots{}]
3221 When used together with the @option{--upgrade} option, do @emph{not}
3222 upgrade any packages whose name matches a @var{regexp}. For example, to
3223 upgrade all packages in the current profile except those containing the
3224 substring ``emacs'':
3227 $ guix package --upgrade . --do-not-upgrade emacs
3230 @item @anchor{profile-manifest}--manifest=@var{file}
3231 @itemx -m @var{file}
3232 @cindex profile declaration
3233 @cindex profile manifest
3234 Create a new generation of the profile from the manifest object
3235 returned by the Scheme code in @var{file}. This option can be repeated
3236 several times, in which case the manifests are concatenated.
3238 This allows you to @emph{declare} the profile's contents rather than
3239 constructing it through a sequence of @option{--install} and similar
3240 commands. The advantage is that @var{file} can be put under version
3241 control, copied to different machines to reproduce the same profile, and
3244 @c FIXME: Add reference to (guix profile) documentation when available.
3245 @var{file} must return a @dfn{manifest} object, which is roughly a list
3248 @findex packages->manifest
3250 (use-package-modules guile emacs)
3255 ;; Use a specific package output.
3256 (list guile-2.0 "debug")))
3259 @findex specifications->manifest
3260 In this example we have to know which modules define the @code{emacs}
3261 and @code{guile-2.0} variables to provide the right
3262 @code{use-package-modules} line, which can be cumbersome. We can
3263 instead provide regular package specifications and let
3264 @code{specifications->manifest} look up the corresponding package
3268 (specifications->manifest
3269 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
3273 @cindex rolling back
3274 @cindex undoing transactions
3275 @cindex transactions, undoing
3276 Roll back to the previous @dfn{generation} of the profile---i.e., undo
3277 the last transaction.
3279 When combined with options such as @option{--install}, roll back occurs
3280 before any other actions.
3282 When rolling back from the first generation that actually contains
3283 installed packages, the profile is made to point to the @dfn{zeroth
3284 generation}, which contains no files apart from its own metadata.
3286 After having rolled back, installing, removing, or upgrading packages
3287 overwrites previous future generations. Thus, the history of the
3288 generations in a profile is always linear.
3290 @item --switch-generation=@var{pattern}
3291 @itemx -S @var{pattern}
3293 Switch to a particular generation defined by @var{pattern}.
3295 @var{pattern} may be either a generation number or a number prefixed
3296 with ``+'' or ``-''. The latter means: move forward/backward by a
3297 specified number of generations. For example, if you want to return to
3298 the latest generation after @option{--roll-back}, use
3299 @option{--switch-generation=+1}.
3301 The difference between @option{--roll-back} and
3302 @option{--switch-generation=-1} is that @option{--switch-generation} will
3303 not make a zeroth generation, so if a specified generation does not
3304 exist, the current generation will not be changed.
3306 @item --search-paths[=@var{kind}]
3307 @cindex search paths
3308 Report environment variable definitions, in Bash syntax, that may be
3309 needed in order to use the set of installed packages. These environment
3310 variables are used to specify @dfn{search paths} for files used by some
3311 of the installed packages.
3313 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
3314 environment variables to be defined so it can look for headers and
3315 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
3316 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
3317 library are installed in the profile, then @option{--search-paths} will
3318 suggest setting these variables to @file{@var{profile}/include} and
3319 @file{@var{profile}/lib}, respectively.
3321 The typical use case is to define these environment variables in the
3325 $ eval `guix package --search-paths`
3328 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
3329 meaning that the returned environment variable definitions will either
3330 be exact settings, or prefixes or suffixes of the current value of these
3331 variables. When omitted, @var{kind} defaults to @code{exact}.
3333 This option can also be used to compute the @emph{combined} search paths
3334 of several profiles. Consider this example:
3337 $ guix package -p foo -i guile
3338 $ guix package -p bar -i guile-json
3339 $ guix package -p foo -p bar --search-paths
3342 The last command above reports about the @env{GUILE_LOAD_PATH}
3343 variable, even though, taken individually, neither @file{foo} nor
3344 @file{bar} would lead to that recommendation.
3347 @item --profile=@var{profile}
3348 @itemx -p @var{profile}
3349 Use @var{profile} instead of the user's default profile.
3351 @var{profile} must be the name of a file that will be created upon
3352 completion. Concretely, @var{profile} will be a mere symbolic link
3353 (``symlink'') pointing to the actual profile where packages are
3357 $ guix install hello -p ~/code/my-profile
3359 $ ~/code/my-profile/bin/hello
3363 All it takes to get rid of the profile is to remove this symlink and its
3364 siblings that point to specific generations:
3367 $ rm ~/code/my-profile ~/code/my-profile-*-link
3370 @item --list-profiles
3371 List all the user's profiles:
3374 $ guix package --list-profiles
3375 /home/charlie/.guix-profile
3376 /home/charlie/code/my-profile
3377 /home/charlie/code/devel-profile
3378 /home/charlie/tmp/test
3381 When running as root, list all the profiles of all the users.
3383 @cindex collisions, in a profile
3384 @cindex colliding packages in profiles
3385 @cindex profile collisions
3386 @item --allow-collisions
3387 Allow colliding packages in the new profile. Use at your own risk!
3389 By default, @command{guix package} reports as an error @dfn{collisions}
3390 in the profile. Collisions happen when two or more different versions
3391 or variants of a given package end up in the profile.
3394 Use the bootstrap Guile to build the profile. This option is only
3395 useful to distribution developers.
3399 In addition to these actions, @command{guix package} supports the
3400 following options to query the current state of a profile, or the
3401 availability of packages:
3405 @item --search=@var{regexp}
3406 @itemx -s @var{regexp}
3407 @anchor{guix-search}
3408 @cindex searching for packages
3409 List the available packages whose name, synopsis, or description matches
3410 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3411 Print all the metadata of matching packages in
3412 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3413 GNU recutils manual}).
3415 This allows specific fields to be extracted using the @command{recsel}
3416 command, for instance:
3419 $ guix package -s malloc | recsel -p name,version,relevance
3433 Similarly, to show the name of all the packages available under the
3434 terms of the GNU@tie{}LGPL version 3:
3437 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3444 It is also possible to refine search results using several @code{-s} flags to
3445 @command{guix package}, or several arguments to @command{guix search}. For
3446 example, the following command returns a list of board games (this time using
3447 the @command{guix search} alias):
3450 $ guix search '\<board\>' game | recsel -p name
3455 If we were to omit @code{-s game}, we would also get software packages
3456 that deal with printed circuit boards; removing the angle brackets
3457 around @code{board} would further add packages that have to do with
3460 And now for a more elaborate example. The following command searches
3461 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3462 libraries, and prints the name and synopsis of the matching packages:
3465 $ guix search crypto library | \
3466 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3470 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3471 information on @dfn{selection expressions} for @code{recsel -e}.
3473 @item --show=@var{package}
3474 Show details about @var{package}, taken from the list of available packages, in
3475 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3479 $ guix package --show=python | recsel -p name,version
3487 You may also specify the full name of a package to only get details about a
3488 specific version of it (this time using the @command{guix show} alias):
3490 $ guix show python@@3.4 | recsel -p name,version
3497 @item --list-installed[=@var{regexp}]
3498 @itemx -I [@var{regexp}]
3499 List the currently installed packages in the specified profile, with the
3500 most recently installed packages shown last. When @var{regexp} is
3501 specified, list only installed packages whose name matches @var{regexp}.
3503 For each installed package, print the following items, separated by
3504 tabs: the package name, its version string, the part of the package that
3505 is installed (for instance, @code{out} for the default output,
3506 @code{include} for its headers, etc.), and the path of this package in
3509 @item --list-available[=@var{regexp}]
3510 @itemx -A [@var{regexp}]
3511 List packages currently available in the distribution for this system
3512 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3513 available packages whose name matches @var{regexp}.
3515 For each package, print the following items separated by tabs: its name,
3516 its version string, the parts of the package (@pxref{Packages with
3517 Multiple Outputs}), and the source location of its definition.
3519 @item --list-generations[=@var{pattern}]
3520 @itemx -l [@var{pattern}]
3522 Return a list of generations along with their creation dates; for each
3523 generation, show the installed packages, with the most recently
3524 installed packages shown last. Note that the zeroth generation is never
3527 For each installed package, print the following items, separated by
3528 tabs: the name of a package, its version string, the part of the package
3529 that is installed (@pxref{Packages with Multiple Outputs}), and the
3530 location of this package in the store.
3532 When @var{pattern} is used, the command returns only matching
3533 generations. Valid patterns include:
3536 @item @emph{Integers and comma-separated integers}. Both patterns denote
3537 generation numbers. For instance, @option{--list-generations=1} returns
3540 And @option{--list-generations=1,8,2} outputs three generations in the
3541 specified order. Neither spaces nor trailing commas are allowed.
3543 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3544 specified generations and everything in between. Note that the start of
3545 a range must be smaller than its end.
3547 It is also possible to omit the endpoint. For example,
3548 @option{--list-generations=2..}, returns all generations starting from the
3551 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3552 or months by passing an integer along with the first letter of the
3553 duration. For example, @option{--list-generations=20d} lists generations
3554 that are up to 20 days old.
3557 @item --delete-generations[=@var{pattern}]
3558 @itemx -d [@var{pattern}]
3559 When @var{pattern} is omitted, delete all generations except the current
3562 This command accepts the same patterns as @option{--list-generations}.
3563 When @var{pattern} is specified, delete the matching generations. When
3564 @var{pattern} specifies a duration, generations @emph{older} than the
3565 specified duration match. For instance, @option{--delete-generations=1m}
3566 deletes generations that are more than one month old.
3568 If the current generation matches, it is @emph{not} deleted. Also, the
3569 zeroth generation is never deleted.
3571 Note that deleting generations prevents rolling back to them.
3572 Consequently, this command must be used with care.
3576 Finally, since @command{guix package} may actually start build
3577 processes, it supports all the common build options (@pxref{Common Build
3578 Options}). It also supports package transformation options, such as
3579 @option{--with-source} (@pxref{Package Transformation Options}).
3580 However, note that package transformations are lost when upgrading; to
3581 preserve transformations across upgrades, you should define your own
3582 package variant in a Guile module and add it to @env{GUIX_PACKAGE_PATH}
3583 (@pxref{Defining Packages}).
3586 @section Substitutes
3589 @cindex pre-built binaries
3590 Guix supports transparent source/binary deployment, which means that it
3591 can either build things locally, or download pre-built items from a
3592 server, or both. We call these pre-built items @dfn{substitutes}---they
3593 are substitutes for local build results. In many cases, downloading a
3594 substitute is much faster than building things locally.
3596 Substitutes can be anything resulting from a derivation build
3597 (@pxref{Derivations}). Of course, in the common case, they are
3598 pre-built package binaries, but source tarballs, for instance, which
3599 also result from derivation builds, can be available as substitutes.
3602 * Official Substitute Server:: One particular source of substitutes.
3603 * Substitute Server Authorization:: How to enable or disable substitutes.
3604 * Getting Substitutes from Other Servers:: Substitute diversity.
3605 * Substitute Authentication:: How Guix verifies substitutes.
3606 * Proxy Settings:: How to get substitutes via proxy.
3607 * Substitution Failure:: What happens when substitution fails.
3608 * On Trusting Binaries:: How can you trust that binary blob?
3611 @node Official Substitute Server
3612 @subsection Official Substitute Server
3615 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3616 that builds packages from Guix continuously for some
3617 architectures, and makes them available as substitutes. This is the
3618 default source of substitutes; it can be overridden by passing the
3619 @option{--substitute-urls} option either to @command{guix-daemon}
3620 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3621 or to client tools such as @command{guix package}
3622 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3625 Substitute URLs can be either HTTP or HTTPS.
3626 HTTPS is recommended because communications are encrypted; conversely,
3627 using HTTP makes all communications visible to an eavesdropper, who
3628 could use the information gathered to determine, for instance, whether
3629 your system has unpatched security vulnerabilities.
3631 Substitutes from the official build farm are enabled by default when
3632 using Guix System (@pxref{GNU Distribution}). However,
3633 they are disabled by default when using Guix on a foreign distribution,
3634 unless you have explicitly enabled them via one of the recommended
3635 installation steps (@pxref{Installation}). The following paragraphs
3636 describe how to enable or disable substitutes for the official build
3637 farm; the same procedure can also be used to enable substitutes for any
3638 other substitute server.
3640 @node Substitute Server Authorization
3641 @subsection Substitute Server Authorization
3644 @cindex substitutes, authorization thereof
3645 @cindex access control list (ACL), for substitutes
3646 @cindex ACL (access control list), for substitutes
3647 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3649 must add its public key to the access control list (ACL) of archive
3650 imports, using the @command{guix archive} command (@pxref{Invoking guix
3651 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3652 be compromised and to serve genuine substitutes.
3655 If you are using Guix System, you can skip this section: Guix System
3656 authorizes substitutes from @code{@value{SUBSTITUTE-SERVER}} by default.
3659 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3660 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3661 the installation prefix of Guix. If you installed Guix from source,
3662 make sure you checked the GPG signature of
3663 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3664 Then, you can run something like this:
3667 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3670 Once this is in place, the output of a command like @code{guix build}
3671 should change from something like:
3674 $ guix build emacs --dry-run
3675 The following derivations would be built:
3676 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3677 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3678 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3679 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3687 $ guix build emacs --dry-run
3688 112.3 MB would be downloaded:
3689 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3690 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3691 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3692 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3697 The text changed from ``The following derivations would be built'' to
3698 ``112.3 MB would be downloaded''. This indicates that substitutes from
3699 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3700 possible, for future builds.
3702 @cindex substitutes, how to disable
3703 The substitute mechanism can be disabled globally by running
3704 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3705 guix-daemon}). It can also be disabled temporarily by passing the
3706 @option{--no-substitutes} option to @command{guix package},
3707 @command{guix build}, and other command-line tools.
3709 @node Getting Substitutes from Other Servers
3710 @subsection Getting Substitutes from Other Servers
3712 @cindex substitute servers, adding more
3713 Guix can look up and fetch substitutes from several servers. This is
3714 useful when you are using packages from additional channels for which
3715 the official server does not have substitutes but another server
3716 provides them. Another situation where this is useful is when you would
3717 prefer to download from your organization's substitute server, resorting
3718 to the official server only as a fallback or dismissing it altogether.
3720 You can give Guix a list of substitute server URLs and it will check
3721 them in the specified order. You also need to explicitly authorize the
3722 public keys of substitute servers to instruct Guix to accept the
3723 substitutes they sign.
3725 On Guix System, this is achieved by modifying the configuration of the
3726 @code{guix} service. Since the @code{guix} service is part of the
3727 default lists of services, @code{%base-services} and
3728 @code{%desktop-services}, you can use @code{modify-services} to change
3729 its configuration and add the URLs and substitute keys that you want
3730 (@pxref{Service Reference, @code{modify-services}}).
3732 As an example, suppose you want to fetch substitutes from
3733 @code{guix.example.org} and to authorize the signing key of that server,
3734 in addition to the default @code{@value{SUBSTITUTE-SERVER}}. The
3735 resulting operating system configuration will look something like:
3741 ;; Assume we're starting from '%desktop-services'. Replace it
3742 ;; with the list of services you're actually using.
3743 (modify-services %desktop-services
3744 (guix-service-type config =>
3748 (append (list "https://guix.example.org")
3749 %default-substitute-urls))
3751 (append (list (local-file "./key.pub"))
3752 %default-authorized-guix-keys)))))))
3755 This assumes that the file @file{key.pub} contains the signing key of
3756 @code{guix.example.org}. With this change in place in your operating
3757 system configuration file (say @file{/etc/config.scm}), you can
3758 reconfigure and restart the @code{guix-daemon} service or reboot so the
3759 changes take effect:
3762 $ sudo guix system reconfigure /etc/config.scm
3763 $ sudo herd restart guix-daemon
3766 If you're running Guix on a ``foreign distro'', you would instead take
3767 the following steps to get substitutes from additional servers:
3771 Edit the service configuration file for @code{guix-daemon}; when using
3772 systemd, this is normally
3773 @file{/etc/systemd/system/guix-daemon.service}. Add the
3774 @option{--substitute-urls} option on the @command{guix-daemon} command
3775 line and list the URLs of interest (@pxref{daemon-substitute-urls,
3776 @code{guix-daemon --substitute-urls}}):
3779 @dots{} --substitute-urls='https://guix.example.org https://@value{SUBSTITUTE-SERVER}'
3783 Restart the daemon. For systemd, it goes like this:
3786 systemctl daemon-reload
3787 systemctl restart guix-daemon.service
3791 Authorize the key of the new server (@pxref{Invoking guix archive}):
3794 guix archive --authorize < key.pub
3797 Again this assumes @file{key.pub} contains the public key that
3798 @code{guix.example.org} uses to sign substitutes.
3801 Now you're all set! Substitutes will be preferably taken from
3802 @code{https://guix.example.org}, using @code{@value{SUBSTITUTE-SERVER}}
3803 as a fallback. Of course you can list as many substitute servers as you
3804 like, with the caveat that substitute lookup can be slowed down if too
3805 many servers need to be contacted.
3807 Note that there are also situations where one may want to add the URL of
3808 a substitute server @emph{without} authorizing its key.
3809 @xref{Substitute Authentication}, to understand this fine point.
3811 @node Substitute Authentication
3812 @subsection Substitute Authentication
3814 @cindex digital signatures
3815 Guix detects and raises an error when attempting to use a substitute
3816 that has been tampered with. Likewise, it ignores substitutes that are
3817 not signed, or that are not signed by one of the keys listed in the ACL.
3819 There is one exception though: if an unauthorized server provides
3820 substitutes that are @emph{bit-for-bit identical} to those provided by
3821 an authorized server, then the unauthorized server becomes eligible for
3822 downloads. For example, assume we have chosen two substitute servers
3826 --substitute-urls="https://a.example.org https://b.example.org"
3830 @cindex reproducible builds
3831 If the ACL contains only the key for @samp{b.example.org}, and if
3832 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3833 then Guix will download substitutes from @samp{a.example.org} because it
3834 comes first in the list and can be considered a mirror of
3835 @samp{b.example.org}. In practice, independent build machines usually
3836 produce the same binaries, thanks to bit-reproducible builds (see
3839 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3840 (in other words, the server is not authenticated), contrary to what
3841 HTTPS clients such as Web browsers usually do. This is because Guix
3842 authenticates substitute information itself, as explained above, which
3843 is what we care about (whereas X.509 certificates are about
3844 authenticating bindings between domain names and public keys).
3846 @node Proxy Settings
3847 @subsection Proxy Settings
3851 Substitutes are downloaded over HTTP or HTTPS. The @env{http_proxy} and
3852 @env{https_proxy} environment variables can be set in the environment of
3853 @command{guix-daemon} and are honored for downloads of substitutes.
3854 Note that the value of those environment variables in the environment
3855 where @command{guix build}, @command{guix package}, and other client
3856 commands are run has @emph{absolutely no effect}.
3858 @node Substitution Failure
3859 @subsection Substitution Failure
3861 Even when a substitute for a derivation is available, sometimes the
3862 substitution attempt will fail. This can happen for a variety of
3863 reasons: the substitute server might be offline, the substitute may
3864 recently have been deleted, the connection might have been interrupted,
3867 When substitutes are enabled and a substitute for a derivation is
3868 available, but the substitution attempt fails, Guix will attempt to
3869 build the derivation locally depending on whether or not
3870 @option{--fallback} was given (@pxref{fallback-option,, common build
3871 option @option{--fallback}}). Specifically, if @option{--fallback} was
3872 omitted, then no local build will be performed, and the derivation is
3873 considered to have failed. However, if @option{--fallback} was given,
3874 then Guix will attempt to build the derivation locally, and the success
3875 or failure of the derivation depends on the success or failure of the
3876 local build. Note that when substitutes are disabled or no substitute
3877 is available for the derivation in question, a local build will
3878 @emph{always} be performed, regardless of whether or not
3879 @option{--fallback} was given.
3881 To get an idea of how many substitutes are available right now, you can
3882 try running the @command{guix weather} command (@pxref{Invoking guix
3883 weather}). This command provides statistics on the substitutes provided
3886 @node On Trusting Binaries
3887 @subsection On Trusting Binaries
3889 @cindex trust, of pre-built binaries
3890 Today, each individual's control over their own computing is at the
3891 mercy of institutions, corporations, and groups with enough power and
3892 determination to subvert the computing infrastructure and exploit its
3893 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3894 convenient, we encourage users to also build on their own, or even run
3895 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3896 interesting target. One way to help is by publishing the software you
3897 build using @command{guix publish} so that others have one more choice
3898 of server to download substitutes from (@pxref{Invoking guix publish}).
3900 Guix has the foundations to maximize build reproducibility
3901 (@pxref{Features}). In most cases, independent builds of a given
3902 package or derivation should yield bit-identical results. Thus, through
3903 a diverse set of independent package builds, we can strengthen the
3904 integrity of our systems. The @command{guix challenge} command aims to
3905 help users assess substitute servers, and to assist developers in
3906 finding out about non-deterministic package builds (@pxref{Invoking guix
3907 challenge}). Similarly, the @option{--check} option of @command{guix
3908 build} allows users to check whether previously-installed substitutes
3909 are genuine by rebuilding them locally (@pxref{build-check,
3910 @command{guix build --check}}).
3912 In the future, we want Guix to have support to publish and retrieve
3913 binaries to/from other users, in a peer-to-peer fashion. If you would
3914 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
3916 @node Packages with Multiple Outputs
3917 @section Packages with Multiple Outputs
3919 @cindex multiple-output packages
3920 @cindex package outputs
3923 Often, packages defined in Guix have a single @dfn{output}---i.e., the
3924 source package leads to exactly one directory in the store. When running
3925 @command{guix install glibc}, one installs the default output of the
3926 GNU libc package; the default output is called @code{out}, but its name
3927 can be omitted as shown in this command. In this particular case, the
3928 default output of @code{glibc} contains all the C header files, shared
3929 libraries, static libraries, Info documentation, and other supporting
3932 Sometimes it is more appropriate to separate the various types of files
3933 produced from a single source package into separate outputs. For
3934 instance, the GLib C library (used by GTK+ and related packages)
3935 installs more than 20 MiB of reference documentation as HTML pages.
3936 To save space for users who do not need it, the documentation goes to a
3937 separate output, called @code{doc}. To install the main GLib output,
3938 which contains everything but the documentation, one would run:
3944 @cindex documentation
3945 The command to install its documentation is:
3948 guix install glib:doc
3951 Some packages install programs with different ``dependency footprints''.
3952 For instance, the WordNet package installs both command-line tools and
3953 graphical user interfaces (GUIs). The former depend solely on the C
3954 library, whereas the latter depend on Tcl/Tk and the underlying X
3955 libraries. In this case, we leave the command-line tools in the default
3956 output, whereas the GUIs are in a separate output. This allows users
3957 who do not need the GUIs to save space. The @command{guix size} command
3958 can help find out about such situations (@pxref{Invoking guix size}).
3959 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
3961 There are several such multiple-output packages in the GNU distribution.
3962 Other conventional output names include @code{lib} for libraries and
3963 possibly header files, @code{bin} for stand-alone programs, and
3964 @code{debug} for debugging information (@pxref{Installing Debugging
3965 Files}). The outputs of a packages are listed in the third column of
3966 the output of @command{guix package --list-available} (@pxref{Invoking
3970 @node Invoking guix gc
3971 @section Invoking @command{guix gc}
3973 @cindex garbage collector
3975 Packages that are installed, but not used, may be @dfn{garbage-collected}.
3976 The @command{guix gc} command allows users to explicitly run the garbage
3977 collector to reclaim space from the @file{/gnu/store} directory. It is
3978 the @emph{only} way to remove files from @file{/gnu/store}---removing
3979 files or directories manually may break it beyond repair!
3982 @cindex garbage collector roots
3983 The garbage collector has a set of known @dfn{roots}: any file under
3984 @file{/gnu/store} reachable from a root is considered @dfn{live} and
3985 cannot be deleted; any other file is considered @dfn{dead} and may be
3986 deleted. The set of garbage collector roots (``GC roots'' for short)
3987 includes default user profiles; by default, the symlinks under
3988 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
3989 added with @command{guix build --root}, for example (@pxref{Invoking
3990 guix build}). The @command{guix gc --list-roots} command lists them.
3992 Prior to running @code{guix gc --collect-garbage} to make space, it is
3993 often useful to remove old generations from user profiles; that way, old
3994 package builds referenced by those generations can be reclaimed. This
3995 is achieved by running @code{guix package --delete-generations}
3996 (@pxref{Invoking guix package}).
3998 Our recommendation is to run a garbage collection periodically, or when
3999 you are short on disk space. For instance, to guarantee that at least
4000 5@tie{}GB are available on your disk, simply run:
4006 It is perfectly safe to run as a non-interactive periodic job
4007 (@pxref{Scheduled Job Execution}, for how to set up such a job).
4008 Running @command{guix gc} with no arguments will collect as
4009 much garbage as it can, but that is often inconvenient: you may find
4010 yourself having to rebuild or re-download software that is ``dead'' from
4011 the GC viewpoint but that is necessary to build other pieces of
4012 software---e.g., the compiler tool chain.
4014 The @command{guix gc} command has three modes of operation: it can be
4015 used to garbage-collect any dead files (the default), to delete specific
4016 files (the @option{--delete} option), to print garbage-collector
4017 information, or for more advanced queries. The garbage collection
4018 options are as follows:
4021 @item --collect-garbage[=@var{min}]
4022 @itemx -C [@var{min}]
4023 Collect garbage---i.e., unreachable @file{/gnu/store} files and
4024 sub-directories. This is the default operation when no option is
4027 When @var{min} is given, stop once @var{min} bytes have been collected.
4028 @var{min} may be a number of bytes, or it may include a unit as a
4029 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
4030 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
4032 When @var{min} is omitted, collect all the garbage.
4034 @item --free-space=@var{free}
4035 @itemx -F @var{free}
4036 Collect garbage until @var{free} space is available under
4037 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
4038 as @code{500MiB}, as described above.
4040 When @var{free} or more is already available in @file{/gnu/store}, do
4041 nothing and exit immediately.
4043 @item --delete-generations[=@var{duration}]
4044 @itemx -d [@var{duration}]
4045 Before starting the garbage collection process, delete all the generations
4046 older than @var{duration}, for all the user profiles; when run as root, this
4047 applies to all the profiles @emph{of all the users}.
4049 For example, this command deletes all the generations of all your profiles
4050 that are older than 2 months (except generations that are current), and then
4051 proceeds to free space until at least 10 GiB are available:
4054 guix gc -d 2m -F 10G
4059 Attempt to delete all the store files and directories specified as
4060 arguments. This fails if some of the files are not in the store, or if
4061 they are still live.
4063 @item --list-failures
4064 List store items corresponding to cached build failures.
4066 This prints nothing unless the daemon was started with
4067 @option{--cache-failures} (@pxref{Invoking guix-daemon,
4068 @option{--cache-failures}}).
4071 List the GC roots owned by the user; when run as root, list @emph{all} the GC
4075 List store items in use by currently running processes. These store
4076 items are effectively considered GC roots: they cannot be deleted.
4078 @item --clear-failures
4079 Remove the specified store items from the failed-build cache.
4081 Again, this option only makes sense when the daemon is started with
4082 @option{--cache-failures}. Otherwise, it does nothing.
4085 Show the list of dead files and directories still present in the
4086 store---i.e., files and directories no longer reachable from any root.
4089 Show the list of live store files and directories.
4093 In addition, the references among existing store files can be queried:
4099 @cindex package dependencies
4100 List the references (respectively, the referrers) of store files given
4106 List the requisites of the store files passed as arguments. Requisites
4107 include the store files themselves, their references, and the references
4108 of these, recursively. In other words, the returned list is the
4109 @dfn{transitive closure} of the store files.
4111 @xref{Invoking guix size}, for a tool to profile the size of the closure
4112 of an element. @xref{Invoking guix graph}, for a tool to visualize
4113 the graph of references.
4117 Return the derivation(s) leading to the given store items
4118 (@pxref{Derivations}).
4120 For example, this command:
4123 guix gc --derivers `guix package -I ^emacs$ | cut -f4`
4127 returns the @file{.drv} file(s) leading to the @code{emacs} package
4128 installed in your profile.
4130 Note that there may be zero matching @file{.drv} files, for instance
4131 because these files have been garbage-collected. There can also be more
4132 than one matching @file{.drv} due to fixed-output derivations.
4135 Lastly, the following options allow you to check the integrity of the
4136 store and to control disk usage.
4140 @item --verify[=@var{options}]
4141 @cindex integrity, of the store
4142 @cindex integrity checking
4143 Verify the integrity of the store.
4145 By default, make sure that all the store items marked as valid in the
4146 database of the daemon actually exist in @file{/gnu/store}.
4148 When provided, @var{options} must be a comma-separated list containing one
4149 or more of @code{contents} and @code{repair}.
4151 When passing @option{--verify=contents}, the daemon computes the
4152 content hash of each store item and compares it against its hash in the
4153 database. Hash mismatches are reported as data corruptions. Because it
4154 traverses @emph{all the files in the store}, this command can take a
4155 long time, especially on systems with a slow disk drive.
4157 @cindex repairing the store
4158 @cindex corruption, recovering from
4159 Using @option{--verify=repair} or @option{--verify=contents,repair}
4160 causes the daemon to try to repair corrupt store items by fetching
4161 substitutes for them (@pxref{Substitutes}). Because repairing is not
4162 atomic, and thus potentially dangerous, it is available only to the
4163 system administrator. A lightweight alternative, when you know exactly
4164 which items in the store are corrupt, is @command{guix build --repair}
4165 (@pxref{Invoking guix build}).
4168 @cindex deduplication
4169 Optimize the store by hard-linking identical files---this is
4170 @dfn{deduplication}.
4172 The daemon performs deduplication after each successful build or archive
4173 import, unless it was started with @option{--disable-deduplication}
4174 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
4175 this option is primarily useful when the daemon was running with
4176 @option{--disable-deduplication}.
4180 @node Invoking guix pull
4181 @section Invoking @command{guix pull}
4183 @cindex upgrading Guix
4184 @cindex updating Guix
4185 @cindex @command{guix pull}
4187 @cindex security, @command{guix pull}
4188 @cindex authenticity, of code obtained with @command{guix pull}
4189 Packages are installed or upgraded to the latest version available in
4190 the distribution currently available on your local machine. To update
4191 that distribution, along with the Guix tools, you must run @command{guix
4192 pull}: the command downloads the latest Guix source code and package
4193 descriptions, and deploys it. Source code is downloaded from a
4194 @uref{https://git-scm.com, Git} repository, by default the official
4195 GNU@tie{}Guix repository, though this can be customized. @command{guix
4196 pull} ensures that the code it downloads is @emph{authentic} by
4197 verifying that commits are signed by Guix developers.
4199 Specifically, @command{guix pull} downloads code from the @dfn{channels}
4200 (@pxref{Channels}) specified by one of the followings, in this order:
4204 the @option{--channels} option;
4206 the user's @file{~/.config/guix/channels.scm} file;
4208 the system-wide @file{/etc/guix/channels.scm} file;
4210 the built-in default channels specified in the @code{%default-channels}
4214 On completion, @command{guix package} will use packages and package
4215 versions from this just-retrieved copy of Guix. Not only that, but all
4216 the Guix commands and Scheme modules will also be taken from that latest
4217 version. New @command{guix} sub-commands added by the update also
4220 Any user can update their Guix copy using @command{guix pull}, and the
4221 effect is limited to the user who ran @command{guix pull}. For
4222 instance, when user @code{root} runs @command{guix pull}, this has no
4223 effect on the version of Guix that user @code{alice} sees, and vice
4226 The result of running @command{guix pull} is a @dfn{profile} available
4227 under @file{~/.config/guix/current} containing the latest Guix. Thus,
4228 make sure to add it to the beginning of your search path so that you use
4229 the latest version, and similarly for the Info manual
4230 (@pxref{Documentation}):
4233 export PATH="$HOME/.config/guix/current/bin:$PATH"
4234 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
4237 The @option{--list-generations} or @option{-l} option lists past generations
4238 produced by @command{guix pull}, along with details about their provenance:
4242 Generation 1 Jun 10 2018 00:18:18
4244 repository URL: https://git.savannah.gnu.org/git/guix.git
4245 branch: origin/master
4246 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
4248 Generation 2 Jun 11 2018 11:02:49
4250 repository URL: https://git.savannah.gnu.org/git/guix.git
4251 branch: origin/master
4252 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
4253 2 new packages: keepalived, libnfnetlink
4254 6 packages upgraded: emacs-nix-mode@@2.0.4,
4255 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
4256 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
4258 Generation 3 Jun 13 2018 23:31:07 (current)
4260 repository URL: https://git.savannah.gnu.org/git/guix.git
4261 branch: origin/master
4262 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
4263 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
4264 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
4267 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
4268 describe the current status of Guix.
4270 This @code{~/.config/guix/current} profile works exactly like the profiles
4271 created by @command{guix package} (@pxref{Invoking guix package}). That
4272 is, you can list generations, roll back to the previous
4273 generation---i.e., the previous Guix---and so on:
4276 $ guix pull --roll-back
4277 switched from generation 3 to 2
4278 $ guix pull --delete-generations=1
4279 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4282 You can also use @command{guix package} (@pxref{Invoking guix package})
4283 to manage the profile by naming it explicitly:
4285 $ guix package -p ~/.config/guix/current --roll-back
4286 switched from generation 3 to 2
4287 $ guix package -p ~/.config/guix/current --delete-generations=1
4288 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4291 The @command{guix pull} command is usually invoked with no arguments,
4292 but it supports the following options:
4295 @item --url=@var{url}
4296 @itemx --commit=@var{commit}
4297 @itemx --branch=@var{branch}
4298 Download code for the @code{guix} channel from the specified @var{url}, at the
4299 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4300 string), or @var{branch}.
4302 @cindex @file{channels.scm}, configuration file
4303 @cindex configuration file for channels
4304 These options are provided for convenience, but you can also specify your
4305 configuration in the @file{~/.config/guix/channels.scm} file or using the
4306 @option{--channels} option (see below).
4308 @item --channels=@var{file}
4309 @itemx -C @var{file}
4310 Read the list of channels from @var{file} instead of
4311 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
4312 @var{file} must contain Scheme code that
4313 evaluates to a list of channel objects. @xref{Channels}, for more
4316 @cindex channel news
4319 Display the list of packages added or upgraded since the previous
4320 generation, as well as, occasionally, news written by channel authors
4321 for their users (@pxref{Channels, Writing Channel News}).
4323 The package information is the same as displayed upon @command{guix
4324 pull} completion, but without ellipses; it is also similar to the output
4325 of @command{guix pull -l} for the last generation (see below).
4327 @item --list-generations[=@var{pattern}]
4328 @itemx -l [@var{pattern}]
4329 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
4330 is provided, the subset of generations that match @var{pattern}.
4331 The syntax of @var{pattern} is the same as with @code{guix package
4332 --list-generations} (@pxref{Invoking guix package}).
4335 @cindex rolling back
4336 @cindex undoing transactions
4337 @cindex transactions, undoing
4338 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
4339 undo the last transaction.
4341 @item --switch-generation=@var{pattern}
4342 @itemx -S @var{pattern}
4344 Switch to a particular generation defined by @var{pattern}.
4346 @var{pattern} may be either a generation number or a number prefixed
4347 with ``+'' or ``-''. The latter means: move forward/backward by a
4348 specified number of generations. For example, if you want to return to
4349 the latest generation after @option{--roll-back}, use
4350 @option{--switch-generation=+1}.
4352 @item --delete-generations[=@var{pattern}]
4353 @itemx -d [@var{pattern}]
4354 When @var{pattern} is omitted, delete all generations except the current
4357 This command accepts the same patterns as @option{--list-generations}.
4358 When @var{pattern} is specified, delete the matching generations. When
4359 @var{pattern} specifies a duration, generations @emph{older} than the
4360 specified duration match. For instance, @option{--delete-generations=1m}
4361 deletes generations that are more than one month old.
4363 If the current generation matches, it is @emph{not} deleted.
4365 Note that deleting generations prevents rolling back to them.
4366 Consequently, this command must be used with care.
4368 @xref{Invoking guix describe}, for a way to display information about the
4369 current generation only.
4371 @item --profile=@var{profile}
4372 @itemx -p @var{profile}
4373 Use @var{profile} instead of @file{~/.config/guix/current}.
4377 Show which channel commit(s) would be used and what would be built or
4378 substituted but do not actually do it.
4380 @item --allow-downgrades
4381 Allow pulling older or unrelated revisions of channels than those
4384 @cindex downgrade attacks, protection against
4385 By default, @command{guix pull} protects against so-called ``downgrade
4386 attacks'' whereby the Git repository of a channel would be reset to an
4387 earlier or unrelated revision of itself, potentially leading you to
4388 install older, known-vulnerable versions of software packages.
4391 Make sure you understand its security implications before using
4392 @option{--allow-downgrades}.
4395 @item --disable-authentication
4396 Allow pulling channel code without authenticating it.
4398 @cindex authentication, of channel code
4399 By default, @command{guix pull} authenticates code downloaded from
4400 channels by verifying that its commits are signed by authorized
4401 developers, and raises an error if this is not the case. This option
4402 instructs it to not perform any such verification.
4405 Make sure you understand its security implications before using
4406 @option{--disable-authentication}.
4409 @item --system=@var{system}
4410 @itemx -s @var{system}
4411 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4412 the system type of the build host.
4415 Use the bootstrap Guile to build the latest Guix. This option is only
4416 useful to Guix developers.
4419 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
4420 repository and branch to pull from, as well as @emph{additional} repositories
4421 containing package modules that should be deployed. @xref{Channels}, for more
4424 In addition, @command{guix pull} supports all the common build options
4425 (@pxref{Common Build Options}).
4427 @node Invoking guix time-machine
4428 @section Invoking @command{guix time-machine}
4430 @cindex @command{guix time-machine}
4431 @cindex pinning, channels
4432 @cindex replicating Guix
4433 @cindex reproducibility, of Guix
4435 The @command{guix time-machine} command provides access to other
4436 revisions of Guix, for example to install older versions of packages,
4437 or to reproduce a computation in an identical environment. The revision
4438 of Guix to be used is defined by a commit or by a channel
4439 description file created by @command{guix describe}
4440 (@pxref{Invoking guix describe}).
4442 The general syntax is:
4445 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4448 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4449 @command{guix} command of the specified revision. The @var{options} that define
4450 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4453 @item --url=@var{url}
4454 @itemx --commit=@var{commit}
4455 @itemx --branch=@var{branch}
4456 Use the @code{guix} channel from the specified @var{url}, at the
4457 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4458 string), or @var{branch}.
4460 @item --channels=@var{file}
4461 @itemx -C @var{file}
4462 Read the list of channels from @var{file}. @var{file} must contain
4463 Scheme code that evaluates to a list of channel objects.
4464 @xref{Channels} for more information.
4467 As for @command{guix pull}, the absence of any options means that the
4468 latest commit on the master branch will be used. The command
4471 guix time-machine -- build hello
4474 will thus build the package @code{hello} as defined in the master branch,
4475 which is in general a newer revision of Guix than you have installed.
4476 Time travel works in both directions!
4478 Note that @command{guix time-machine} can trigger builds of channels and
4479 their dependencies, and these are controlled by the standard build
4480 options (@pxref{Common Build Options}).
4485 @c TODO: Remove this once we're more confident about API stability.
4487 The functionality described here is a ``technology preview'' as of version
4488 @value{VERSION}. As such, the interface is subject to change.
4492 @cindex composition of Guix revisions
4493 Sometimes you might need to mix packages from the revision of Guix you're
4494 currently running with packages available in a different revision of Guix.
4495 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4496 revisions in arbitrary ways.
4498 @cindex inferior packages
4499 Technically, an ``inferior'' is essentially a separate Guix process connected
4500 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4501 @code{(guix inferior)} module allows you to create inferiors and to
4502 communicate with them. It also provides a high-level interface to browse and
4503 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4505 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4506 to interact with a separate revision of Guix. For example, let's assume you
4507 want to install in your profile the current @code{guile} package, along with
4508 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4509 because the newer @code{guile-json} has an incompatible API and you want to
4510 run your code against the old API@. To do that, you could write a manifest for
4511 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4512 manifest, you would create an inferior for that old Guix revision you care
4513 about, and you would look up the @code{guile-json} package in the inferior:
4516 (use-modules (guix inferior) (guix channels)
4517 (srfi srfi-1)) ;for 'first'
4520 ;; This is the old revision from which we want to
4521 ;; extract guile-json.
4524 (url "https://git.savannah.gnu.org/git/guix.git")
4526 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4529 ;; An inferior representing the above revision.
4530 (inferior-for-channels channels))
4532 ;; Now create a manifest with the current "guile" package
4533 ;; and the old "guile-json" package.
4535 (list (first (lookup-inferior-packages inferior "guile-json"))
4536 (specification->package "guile")))
4539 On its first run, @command{guix package --manifest} might have to build the
4540 channel you specified before it can create the inferior; subsequent runs will
4541 be much faster because the Guix revision will be cached.
4543 The @code{(guix inferior)} module provides the following procedures to open an
4546 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4547 [#:cache-directory] [#:ttl]
4548 Return an inferior for @var{channels}, a list of channels. Use the cache at
4549 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4550 This procedure opens a new connection to the build daemon.
4552 As a side effect, this procedure may build or substitute binaries for
4553 @var{channels}, which can take time.
4556 @deffn {Scheme Procedure} open-inferior @var{directory} @
4557 [#:command "bin/guix"]
4558 Open the inferior Guix in @var{directory}, running
4559 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4560 the inferior could not be launched.
4563 @cindex inferior packages
4564 The procedures listed below allow you to obtain and manipulate inferior
4567 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4568 Return the list of packages known to @var{inferior}.
4571 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4573 Return the sorted list of inferior packages matching @var{name} in
4574 @var{inferior}, with highest version numbers first. If @var{version} is true,
4575 return only packages with a version number prefixed by @var{version}.
4578 @deffn {Scheme Procedure} inferior-package? @var{obj}
4579 Return true if @var{obj} is an inferior package.
4582 @deffn {Scheme Procedure} inferior-package-name @var{package}
4583 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4584 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4585 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4586 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4587 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4588 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4589 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4590 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4591 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4592 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4593 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4594 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4595 These procedures are the counterpart of package record accessors
4596 (@pxref{package Reference}). Most of them work by querying the inferior
4597 @var{package} comes from, so the inferior must still be live when you call
4601 Inferior packages can be used transparently like any other package or
4602 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4603 transparently handled by the @code{packages->manifest} procedure, which is
4604 commonly use in manifests (@pxref{Invoking guix package, the
4605 @option{--manifest} option of @command{guix package}}). Thus you can insert
4606 an inferior package pretty much anywhere you would insert a regular package:
4607 in manifests, in the @code{packages} field of your @code{operating-system}
4608 declaration, and so on.
4610 @node Invoking guix describe
4611 @section Invoking @command{guix describe}
4613 @cindex reproducibility
4614 @cindex replicating Guix
4615 Often you may want to answer questions like: ``Which revision of Guix am I
4616 using?'' or ``Which channels am I using?'' This is useful information in many
4617 situations: if you want to @emph{replicate} an environment on a different
4618 machine or user account, if you want to report a bug or to determine what
4619 change in the channels you are using caused it, or if you want to record your
4620 system state for reproducibility purposes. The @command{guix describe}
4621 command answers these questions.
4623 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4624 displays the channel(s) that it was built from, including their repository URL
4625 and commit IDs (@pxref{Channels}):
4629 Generation 10 Sep 03 2018 17:32:44 (current)
4631 repository URL: https://git.savannah.gnu.org/git/guix.git
4633 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4636 If you're familiar with the Git version control system, this is similar in
4637 spirit to @command{git describe}; the output is also similar to that of
4638 @command{guix pull --list-generations}, but limited to the current generation
4639 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4640 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4641 information is all it takes to describe the revision of Guix you're using, and
4642 also to replicate it.
4644 To make it easier to replicate Guix, @command{guix describe} can also be asked
4645 to return a list of channels instead of the human-readable description above:
4648 $ guix describe -f channels
4651 (url "https://git.savannah.gnu.org/git/guix.git")
4653 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4655 (make-channel-introduction
4656 "9edb3f66fd807b096b48283debdcddccfea34bad"
4657 (openpgp-fingerprint
4658 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4662 You can save this to a file and feed it to @command{guix pull -C} on some
4663 other machine or at a later point in time, which will instantiate @emph{this
4664 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4665 From there on, since you're able to deploy the same revision of Guix, you can
4666 just as well @emph{replicate a complete software environment}. We humbly
4667 think that this is @emph{awesome}, and we hope you'll like it too!
4669 The details of the options supported by @command{guix describe} are as
4673 @item --format=@var{format}
4674 @itemx -f @var{format}
4675 Produce output in the specified @var{format}, one of:
4679 produce human-readable output;
4681 produce a list of channel specifications that can be passed to @command{guix
4682 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4684 @item channels-sans-intro
4685 like @code{channels}, but omit the @code{introduction} field; use it to
4686 produce a channel specification suitable for Guix version 1.1.0 or
4687 earlier---the @code{introduction} field has to do with channel
4688 authentication (@pxref{Channels, Channel Authentication}) and is not
4689 supported by these older versions;
4692 produce a list of channel specifications in JSON format;
4694 produce a list of channel specifications in Recutils format.
4697 @item --list-formats
4698 Display available formats for @option{--format} option.
4700 @item --profile=@var{profile}
4701 @itemx -p @var{profile}
4702 Display information about @var{profile}.
4705 @node Invoking guix archive
4706 @section Invoking @command{guix archive}
4708 @cindex @command{guix archive}
4710 The @command{guix archive} command allows users to @dfn{export} files
4711 from the store into a single archive, and to later @dfn{import} them on
4712 a machine that runs Guix.
4713 In particular, it allows store files to be transferred from one machine
4714 to the store on another machine.
4717 If you're looking for a way to produce archives in a format suitable for
4718 tools other than Guix, @pxref{Invoking guix pack}.
4721 @cindex exporting store items
4722 To export store files as an archive to standard output, run:
4725 guix archive --export @var{options} @var{specifications}...
4728 @var{specifications} may be either store file names or package
4729 specifications, as for @command{guix package} (@pxref{Invoking guix
4730 package}). For instance, the following command creates an archive
4731 containing the @code{gui} output of the @code{git} package and the main
4732 output of @code{emacs}:
4735 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4738 If the specified packages are not built yet, @command{guix archive}
4739 automatically builds them. The build process may be controlled with the
4740 common build options (@pxref{Common Build Options}).
4742 To transfer the @code{emacs} package to a machine connected over SSH,
4746 guix archive --export -r emacs | ssh the-machine guix archive --import
4750 Similarly, a complete user profile may be transferred from one machine
4751 to another like this:
4754 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4755 ssh the-machine guix archive --import
4759 However, note that, in both examples, all of @code{emacs} and the
4760 profile as well as all of their dependencies are transferred (due to
4761 @option{-r}), regardless of what is already available in the store on
4762 the target machine. The @option{--missing} option can help figure out
4763 which items are missing from the target store. The @command{guix copy}
4764 command simplifies and optimizes this whole process, so this is probably
4765 what you should use in this case (@pxref{Invoking guix copy}).
4767 @cindex nar, archive format
4768 @cindex normalized archive (nar)
4769 @cindex nar bundle, archive format
4770 Each store item is written in the @dfn{normalized archive} or @dfn{nar}
4771 format (described below), and the output of @command{guix archive
4772 --export} (and input of @command{guix archive --import}) is a @dfn{nar
4776 comparable in spirit to `tar', but with differences
4777 that make it more appropriate for our purposes. First, rather than
4778 recording all Unix metadata for each file, the nar format only mentions
4779 the file type (regular, directory, or symbolic link); Unix permissions
4780 and owner/group are dismissed. Second, the order in which directory
4781 entries are stored always follows the order of file names according to
4782 the C locale collation order. This makes archive production fully
4785 That nar bundle format is essentially the concatenation of zero or more
4786 nars along with metadata for each store item it contains: its file name,
4787 references, corresponding derivation, and a digital signature.
4789 When exporting, the daemon digitally signs the contents of the archive,
4790 and that digital signature is appended. When importing, the daemon
4791 verifies the signature and rejects the import in case of an invalid
4792 signature or if the signing key is not authorized.
4793 @c FIXME: Add xref to daemon doc about signatures.
4795 The main options are:
4799 Export the specified store files or packages (see below). Write the
4800 resulting archive to the standard output.
4802 Dependencies are @emph{not} included in the output, unless
4803 @option{--recursive} is passed.
4807 When combined with @option{--export}, this instructs @command{guix archive}
4808 to include dependencies of the given items in the archive. Thus, the
4809 resulting archive is self-contained: it contains the closure of the
4810 exported store items.
4813 Read an archive from the standard input, and import the files listed
4814 therein into the store. Abort if the archive has an invalid digital
4815 signature, or if it is signed by a public key not among the authorized
4816 keys (see @option{--authorize} below).
4819 Read a list of store file names from the standard input, one per line,
4820 and write on the standard output the subset of these files missing from
4823 @item --generate-key[=@var{parameters}]
4824 @cindex signing, archives
4825 Generate a new key pair for the daemon. This is a prerequisite before
4826 archives can be exported with @option{--export}. This
4827 operation is usually instantaneous but it can take time if the system's
4828 entropy pool needs to be refilled. On Guix System,
4829 @code{guix-service-type} takes care of generating this key pair the
4832 The generated key pair is typically stored under @file{/etc/guix}, in
4833 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4834 key, which must be kept secret). When @var{parameters} is omitted,
4835 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4836 versions before 1.6.0, it is a 4096-bit RSA key.
4837 Alternatively, @var{parameters} can specify
4838 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4839 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4840 Libgcrypt Reference Manual}).
4843 @cindex authorizing, archives
4844 Authorize imports signed by the public key passed on standard input.
4845 The public key must be in ``s-expression advanced format''---i.e., the
4846 same format as the @file{signing-key.pub} file.
4848 The list of authorized keys is kept in the human-editable file
4849 @file{/etc/guix/acl}. The file contains
4850 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4851 s-expressions''} and is structured as an access-control list in the
4852 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4855 @item --extract=@var{directory}
4856 @itemx -x @var{directory}
4857 Read a single-item archive as served by substitute servers
4858 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4859 low-level operation needed in only very narrow use cases; see below.
4861 For example, the following command extracts the substitute for Emacs
4862 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4866 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4867 | gunzip | guix archive -x /tmp/emacs
4870 Single-item archives are different from multiple-item archives produced
4871 by @command{guix archive --export}; they contain a single store item,
4872 and they do @emph{not} embed a signature. Thus this operation does
4873 @emph{no} signature verification and its output should be considered
4876 The primary purpose of this operation is to facilitate inspection of
4877 archive contents coming from possibly untrusted substitute servers
4878 (@pxref{Invoking guix challenge}).
4882 Read a single-item archive as served by substitute servers
4883 (@pxref{Substitutes}) and print the list of files it contains, as in
4888 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4889 | lzip -d | guix archive -t
4894 @c *********************************************************************
4899 @cindex @file{channels.scm}, configuration file
4900 @cindex configuration file for channels
4901 @cindex @command{guix pull}, configuration file
4902 @cindex configuration of @command{guix pull}
4903 Guix and its package collection are updated by running @command{guix pull}
4904 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
4905 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
4906 customized by defining @dfn{channels} in the
4907 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
4908 of a Git repository to be deployed, and @command{guix pull} can be instructed
4909 to pull from one or more channels. In other words, channels can be used
4910 to @emph{customize} and to @emph{extend} Guix, as we will see below.
4911 Guix is able to take into account security concerns and deal with authenticated
4915 * Specifying Additional Channels:: Extending the package collection.
4916 * Using a Custom Guix Channel:: Using a customized Guix.
4917 * Replicating Guix:: Running the @emph{exact same} Guix.
4918 * Channel Authentication:: How Guix verifies what it fetches.
4919 * Creating a Channel:: How to write your custom channel.
4920 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
4921 * Declaring Channel Dependencies:: How to depend on other channels.
4922 * Specifying Channel Authorizations:: Defining channel authors authorizations.
4923 * Primary URL:: Distinguishing mirror to original.
4924 * Writing Channel News:: Communicating information to channel's users.
4927 @node Specifying Additional Channels
4928 @section Specifying Additional Channels
4930 @cindex extending the package collection (channels)
4931 @cindex variant packages (channels)
4932 You can specify @emph{additional channels} to pull from. To use a channel, write
4933 @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
4934 @emph{in addition} to the default Guix channel(s):
4936 @vindex %default-channels
4938 ;; Add variant packages to those Guix provides.
4940 (name 'variant-packages)
4941 (url "https://example.org/variant-packages.git"))
4946 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
4947 add a channel the list of channels that the variable @code{%default-channels}
4948 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
4949 Manual}). With this file in place, @command{guix pull} builds not only Guix
4950 but also the package modules from your own repository. The result in
4951 @file{~/.config/guix/current} is the union of Guix with your own package
4955 $ guix pull --list-generations
4957 Generation 19 Aug 27 2018 16:20:48
4959 repository URL: https://git.savannah.gnu.org/git/guix.git
4961 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
4962 variant-packages dd3df5e
4963 repository URL: https://example.org/variant-packages.git
4965 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
4966 11 new packages: variant-gimp, variant-emacs-with-cool-features, @dots{}
4967 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
4971 The output of @command{guix pull} above shows that Generation@tie{}19 includes
4972 both Guix and packages from the @code{variant-personal-packages} channel. Among
4973 the new and upgraded packages that are listed, some like @code{variant-gimp} and
4974 @code{variant-emacs-with-cool-features} might come from
4975 @code{variant-packages}, while others come from the Guix default channel.
4977 @node Using a Custom Guix Channel
4978 @section Using a Custom Guix Channel
4980 The channel called @code{guix} specifies where Guix itself---its command-line
4981 tools as well as its package collection---should be downloaded. For instance,
4982 suppose you want to update from another copy of the Guix repository at
4983 @code{example.org}, and specifically the @code{super-hacks} branch, you can
4984 write in @code{~/.config/guix/channels.scm} this specification:
4987 ;; Tell 'guix pull' to use another repo.
4990 (url "https://example.org/another-guix.git")
4991 (branch "super-hacks")))
4995 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
4996 branch of the repository at @code{example.org}. The authentication concern is
4997 addressed below ((@pxref{Channel Authentication}).
4999 @node Replicating Guix
5000 @section Replicating Guix
5002 @cindex pinning, channels
5003 @cindex replicating Guix
5004 @cindex reproducibility, of Guix
5005 The @command{guix pull --list-generations} output above shows precisely which
5006 commits were used to build this instance of Guix. We can thus replicate it,
5007 say, on another machine, by providing a channel specification in
5008 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
5011 ;; Deploy specific commits of my channels of interest.
5014 (url "https://git.savannah.gnu.org/git/guix.git")
5015 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
5017 (name 'variant-packages)
5018 (url "https://example.org/variant-packages.git")
5019 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
5022 The @command{guix describe --format=channels} command can even generate this
5023 list of channels directly (@pxref{Invoking guix describe}). The resulting
5024 file can be used with the -C options of @command{guix pull}
5025 (@pxref{Invoking guix pull}) or @command{guix time-machine}
5026 (@pxref{Invoking guix time-machine}).
5028 At this point the two machines run the @emph{exact same Guix}, with access to
5029 the @emph{exact same packages}. The output of @command{guix build gimp} on
5030 one machine will be exactly the same, bit for bit, as the output of the same
5031 command on the other machine. It also means both machines have access to all
5032 the source code of Guix and, transitively, to all the source code of every
5035 This gives you super powers, allowing you to track the provenance of binary
5036 artifacts with very fine grain, and to reproduce software environments at
5037 will---some sort of ``meta reproducibility'' capabilities, if you will.
5038 @xref{Inferiors}, for another way to take advantage of these super powers.
5040 @node Channel Authentication
5041 @section Channel Authentication
5043 @anchor{channel-authentication}
5044 @cindex authentication, of channel code
5045 The @command{guix pull} and @command{guix time-machine} commands
5046 @dfn{authenticate} the code retrieved from channels: they make sure each
5047 commit that is fetched is signed by an authorized developer. The goal
5048 is to protect from unauthorized modifications to the channel that would
5049 lead users to run malicious code.
5051 As a user, you must provide a @dfn{channel introduction} in your
5052 channels file so that Guix knows how to authenticate its first commit.
5053 A channel specification, including its introduction, looks something
5058 (name 'some-channel)
5059 (url "https://example.org/some-channel.git")
5061 (make-channel-introduction
5062 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
5063 (openpgp-fingerprint
5064 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5067 The specification above shows the name and URL of the channel. The call
5068 to @code{make-channel-introduction} above specifies that authentication
5069 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
5070 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
5072 For the main channel, called @code{guix}, you automatically get that
5073 information from your Guix installation. For other channels, include
5074 the channel introduction provided by the channel authors in your
5075 @file{channels.scm} file. Make sure you retrieve the channel
5076 introduction from a trusted source since that is the root of your trust.
5078 If you're curious about the authentication mechanics, read on!
5080 @node Creating a Channel
5081 @section Creating a Channel
5083 @cindex personal packages (channels)
5084 @cindex channels, for personal packages
5085 Let's say you have a bunch of custom package variants or personal packages
5086 that you think would make little sense to contribute to the Guix project, but
5087 would like to have these packages transparently available to you at the
5088 command line. You would first write modules containing those package
5089 definitions (@pxref{Package Modules}), maintain them in a Git repository, and
5090 then you and anyone else can use it as an additional channel to get packages
5093 @c What follows stems from discussions at
5094 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
5095 @c earlier discussions on guix-devel@gnu.org.
5097 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
5098 publish your personal channel to the world, we would like to share a few words
5103 Before publishing a channel, please consider contributing your package
5104 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
5105 to free software of all sorts, and packages in Guix proper are readily
5106 available to all Guix users and benefit from the project's quality assurance
5110 When you maintain package definitions outside Guix, we, Guix developers,
5111 consider that @emph{the compatibility burden is on you}. Remember that
5112 package modules and package definitions are just Scheme code that uses various
5113 programming interfaces (APIs). We want to remain free to change these APIs to
5114 keep improving Guix, possibly in ways that break your channel. We never
5115 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
5119 Corollary: if you're using an external channel and that channel breaks, please
5120 @emph{report the issue to the channel authors}, not to the Guix project.
5123 You've been warned! Having said this, we believe external channels are a
5124 practical way to exert your freedom to augment Guix' package collection and to
5125 share your improvements, which are basic tenets of
5126 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
5127 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
5130 To create a channel, create a Git repository containing your own package
5131 modules and make it available. The repository can contain anything, but a
5132 useful channel will contain Guile modules that export packages. Once you
5133 start using a channel, Guix will behave as if the root directory of that
5134 channel's Git repository has been added to the Guile load path (@pxref{Load
5135 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
5136 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
5137 module, then the module will be available under the name @code{(my-packages
5138 my-tools)}, and you will be able to use it like any other module
5139 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
5141 As a channel author, consider bundling authentication material with your
5142 channel so that users can authenticate it. @xref{Channel
5143 Authentication}, and @ref{Specifying Channel Authorizations}, for info
5147 @node Package Modules in a Sub-directory
5148 @section Package Modules in a Sub-directory
5150 @cindex subdirectory, channels
5151 As a channel author, you may want to keep your channel modules in a
5152 sub-directory. If your modules are in the sub-directory @file{guix}, you must
5153 add a meta-data file @file{.guix-channel} that contains:
5161 @node Declaring Channel Dependencies
5162 @section Declaring Channel Dependencies
5164 @cindex dependencies, channels
5165 @cindex meta-data, channels
5166 Channel authors may decide to augment a package collection provided by other
5167 channels. They can declare their channel to be dependent on other channels in
5168 a meta-data file @file{.guix-channel}, which is to be placed in the root of
5169 the channel repository.
5171 The meta-data file should contain a simple S-expression like this:
5178 (name 'some-collection)
5179 (url "https://example.org/first-collection.git")
5181 ;; The 'introduction' bit below is optional: you would
5182 ;; provide it for dependencies that can be authenticated.
5184 (channel-introduction
5186 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
5187 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5189 (name 'some-other-collection)
5190 (url "https://example.org/second-collection.git")
5191 (branch "testing"))))
5194 In the above example this channel is declared to depend on two other channels,
5195 which will both be fetched automatically. The modules provided by the channel
5196 will be compiled in an environment where the modules of all these declared
5197 channels are available.
5199 For the sake of reliability and maintainability, you should avoid dependencies
5200 on channels that you don't control, and you should aim to keep the number of
5201 dependencies to a minimum.
5203 @node Specifying Channel Authorizations
5204 @section Specifying Channel Authorizations
5206 @cindex channel authorizations
5207 @anchor{channel-authorizations}
5208 As we saw above, Guix ensures the source code it pulls from channels
5209 comes from authorized developers. As a channel author, you need to
5210 specify the list of authorized developers in the
5211 @file{.guix-authorizations} file in the channel's Git repository. The
5212 authentication rule is simple: each commit must be signed by a key
5213 listed in the @file{.guix-authorizations} file of its parent
5214 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
5215 (DAG). Each commit can have zero or more parents; ``regular'' commits
5216 have one parent and merge commits have two parent commits. Read
5217 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
5218 for Computer Scientists}} for a great overview.} The
5219 @file{.guix-authorizations} file looks like this:
5222 ;; Example '.guix-authorizations' file.
5225 (version 0) ;current file format version
5227 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
5229 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
5231 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
5235 Each fingerprint is followed by optional key/value pairs, as in the
5236 example above. Currently these key/value pairs are ignored.
5238 This authentication rule creates a chicken-and-egg issue: how do we
5239 authenticate the first commit? Related to that: how do we deal with
5240 channels whose repository history contains unsigned commits and lack
5241 @file{.guix-authorizations}? And how do we fork existing channels?
5243 @cindex channel introduction
5244 Channel introductions answer these questions by describing the first
5245 commit of a channel that should be authenticated. The first time a
5246 channel is fetched with @command{guix pull} or @command{guix
5247 time-machine}, the command looks up the introductory commit and verifies
5248 that it is signed by the specified OpenPGP key. From then on, it
5249 authenticates commits according to the rule above.
5251 Additionally, your channel must provide all the OpenPGP keys that were
5252 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
5253 files, which can be either binary or ``ASCII-armored''. By default,
5254 those @file{.key} files are searched for in the branch named
5255 @code{keyring} but you can specify a different branch name in
5256 @code{.guix-channel} like so:
5261 (keyring-reference "my-keyring-branch"))
5264 To summarize, as the author of a channel, there are three things you have
5265 to do to allow users to authenticate your code:
5269 Export the OpenPGP keys of past and present committers with @command{gpg
5270 --export} and store them in @file{.key} files, by default in a branch
5271 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
5274 Introduce an initial @file{.guix-authorizations} in the channel's
5275 repository. Do that in a signed commit (@pxref{Commit Access}, for
5276 information on how to sign Git commits.)
5279 Advertise the channel introduction, for instance on your channel's web
5280 page. The channel introduction, as we saw above, is the commit/key
5281 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
5282 the fingerprint of the OpenPGP used to sign it.
5285 Before pushing to your public Git repository, you can run @command{guix
5286 git-authenticate} to verify that you did sign all the commits you are
5287 about to push with an authorized key:
5290 guix git authenticate @var{commit} @var{signer}
5294 where @var{commit} and @var{signer} are your channel introduction.
5295 @xref{Invoking guix git authenticate}, for details.
5297 Publishing a signed channel requires discipline: any mistake, such as an
5298 unsigned commit or a commit signed by an unauthorized key, will prevent
5299 users from pulling from your channel---well, that's the whole point of
5300 authentication! Pay attention to merges in particular: merge commits
5301 are considered authentic if and only if they are signed by a key present
5302 in the @file{.guix-authorizations} file of @emph{both} branches.
5305 @section Primary URL
5307 @cindex primary URL, channels
5308 Channel authors can indicate the primary URL of their channel's Git
5309 repository in the @file{.guix-channel} file, like so:
5314 (url "https://example.org/guix.git"))
5317 This allows @command{guix pull} to determine whether it is pulling code
5318 from a mirror of the channel; when that is the case, it warns the user
5319 that the mirror might be stale and displays the primary URL. That way,
5320 users cannot be tricked into fetching code from a stale mirror that does
5321 not receive security updates.
5323 This feature only makes sense for authenticated repositories, such as
5324 the official @code{guix} channel, for which @command{guix pull} ensures
5325 the code it fetches is authentic.
5327 @node Writing Channel News
5328 @section Writing Channel News
5330 @cindex news, for channels
5331 Channel authors may occasionally want to communicate to their users
5332 information about important changes in the channel. You'd send them all
5333 an email, but that's not convenient.
5335 Instead, channels can provide a @dfn{news file}; when the channel users
5336 run @command{guix pull}, that news file is automatically read and
5337 @command{guix pull --news} can display the announcements that correspond
5338 to the new commits that have been pulled, if any.
5340 To do that, channel authors must first declare the name of the news file
5341 in their @file{.guix-channel} file:
5346 (news-file "etc/news.txt"))
5349 The news file itself, @file{etc/news.txt} in this example, must look
5350 something like this:
5355 (entry (tag "the-bug-fix")
5356 (title (en "Fixed terrible bug")
5358 (body (en "@@emph@{Good news@}! It's fixed!")
5359 (eo "Certe ĝi pli bone funkcias nun!")))
5360 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
5361 (title (en "Added a great package")
5362 (ca "Què vol dir guix?"))
5363 (body (en "Don't miss the @@code@{hello@} package!"))))
5366 While the news file is using the Scheme syntax, avoid naming it with a
5367 @file{.scm} extension or else it will get picked up when building the
5368 channel and yield an error since it is not a valid module.
5369 Alternatively, you can move the channel module to a subdirectory and
5370 store the news file in another directory.
5372 The file consists of a list of @dfn{news entries}. Each entry is
5373 associated with a commit or tag: it describes changes made in this
5374 commit, possibly in preceding commits as well. Users see entries only
5375 the first time they obtain the commit the entry refers to.
5377 The @code{title} field should be a one-line summary while @code{body}
5378 can be arbitrarily long, and both can contain Texinfo markup
5379 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
5380 a list of language tag/message tuples, which allows @command{guix pull}
5381 to display news in the language that corresponds to the user's locale.
5383 If you want to translate news using a gettext-based workflow, you can
5384 extract translatable strings with @command{xgettext} (@pxref{xgettext
5385 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
5386 you write news entries in English first, the command below creates a PO
5387 file containing the strings to translate:
5390 xgettext -o news.po -l scheme -ken etc/news.txt
5393 To sum up, yes, you could use your channel as a blog. But beware, this
5394 is @emph{not quite} what your users might expect.
5397 @c *********************************************************************
5399 @chapter Development
5401 @cindex software development
5402 If you are a software developer, Guix provides tools that you should find
5403 helpful---independently of the language you're developing in. This is what
5404 this chapter is about.
5406 The @command{guix environment} command provides a convenient way to set up
5407 @dfn{development environments} containing all the dependencies and tools
5408 necessary to work on the software package of your choice. The @command{guix
5409 pack} command allows you to create @dfn{application bundles} that can be
5410 easily distributed to users who do not run Guix.
5413 * Invoking guix environment:: Setting up development environments.
5414 * Invoking guix pack:: Creating software bundles.
5415 * The GCC toolchain:: Working with languages supported by GCC.
5416 * Invoking guix git authenticate:: Authenticating Git repositories.
5419 @node Invoking guix environment
5420 @section Invoking @command{guix environment}
5422 @cindex reproducible build environments
5423 @cindex development environments
5424 @cindex @command{guix environment}
5425 @cindex environment, package build environment
5426 The purpose of @command{guix environment} is to assist hackers in
5427 creating reproducible development environments without polluting their
5428 package profile. The @command{guix environment} tool takes one or more
5429 packages, builds all of their inputs, and creates a shell
5430 environment to use them.
5432 The general syntax is:
5435 guix environment @var{options} @var{package}@dots{}
5438 The following example spawns a new shell set up for the development of
5442 guix environment guile
5445 If the needed dependencies are not built yet, @command{guix environment}
5446 automatically builds them. The environment of the new shell is an
5447 augmented version of the environment that @command{guix environment} was
5448 run in. It contains the necessary search paths for building the given
5449 package added to the existing environment variables. To create
5450 a ``pure'' environment, in which the original environment variables have
5451 been unset, use the @option{--pure} option@footnote{Users sometimes
5452 wrongfully augment environment variables such as @env{PATH} in their
5453 @file{~/.bashrc} file. As a consequence, when @command{guix
5454 environment} launches it, Bash may read @file{~/.bashrc}, thereby
5455 introducing ``impurities'' in these environment variables. It is an
5456 error to define such environment variables in @file{.bashrc}; instead,
5457 they should be defined in @file{.bash_profile}, which is sourced only by
5458 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
5459 Manual}, for details on Bash start-up files.}.
5461 @vindex GUIX_ENVIRONMENT
5462 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
5463 variable in the shell it spawns; its value is the file name of the
5464 profile of this environment. This allows users to, say, define a
5465 specific prompt for development environments in their @file{.bashrc}
5466 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5469 if [ -n "$GUIX_ENVIRONMENT" ]
5471 export PS1="\u@@\h \w [dev]\$ "
5476 ...@: or to browse the profile:
5479 $ ls "$GUIX_ENVIRONMENT/bin"
5482 Additionally, more than one package may be specified, in which case the
5483 union of the inputs for the given packages are used. For example, the
5484 command below spawns a shell where all of the dependencies of both Guile
5485 and Emacs are available:
5488 guix environment guile emacs
5491 Sometimes an interactive shell session is not desired. An arbitrary
5492 command may be invoked by placing the @code{--} token to separate the
5493 command from the rest of the arguments:
5496 guix environment guile -- make -j4
5499 In other situations, it is more convenient to specify the list of
5500 packages needed in the environment. For example, the following command
5501 runs @command{python} from an environment containing Python@tie{}2.7 and
5505 guix environment --ad-hoc python2-numpy python-2.7 -- python
5508 Furthermore, one might want the dependencies of a package and also some
5509 additional packages that are not build-time or runtime dependencies, but
5510 are useful when developing nonetheless. Because of this, the
5511 @option{--ad-hoc} flag is positional. Packages appearing before
5512 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5513 added to the environment. Packages appearing after are interpreted as
5514 packages that will be added to the environment directly. For example,
5515 the following command creates a Guix development environment that
5516 additionally includes Git and strace:
5519 guix environment --pure guix --ad-hoc git strace
5523 Sometimes it is desirable to isolate the environment as much as
5524 possible, for maximal purity and reproducibility. In particular, when
5525 using Guix on a host distro that is not Guix System, it is desirable to
5526 prevent access to @file{/usr/bin} and other system-wide resources from
5527 the development environment. For example, the following command spawns
5528 a Guile REPL in a ``container'' where only the store and the current
5529 working directory are mounted:
5532 guix environment --ad-hoc --container guile -- guile
5536 The @option{--container} option requires Linux-libre 3.19 or newer.
5539 @cindex certificates
5540 Another typical use case for containers is to run security-sensitive
5541 applications such as a web browser. To run Eolie, we must expose and
5542 share some files and directories; we include @code{nss-certs} and expose
5543 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5544 @env{DISPLAY} environment variable since containerized graphical
5545 applications won't display without it.
5548 guix environment --preserve='^DISPLAY$' --container --network \
5549 --expose=/etc/machine-id \
5550 --expose=/etc/ssl/certs/ \
5551 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5552 --ad-hoc eolie nss-certs dbus -- eolie
5555 The available options are summarized below.
5558 @item --root=@var{file}
5559 @itemx -r @var{file}
5560 @cindex persistent environment
5561 @cindex garbage collector root, for environments
5562 Make @var{file} a symlink to the profile for this environment, and
5563 register it as a garbage collector root.
5565 This is useful if you want to protect your environment from garbage
5566 collection, to make it ``persistent''.
5568 When this option is omitted, the environment is protected from garbage
5569 collection only for the duration of the @command{guix environment}
5570 session. This means that next time you recreate the same environment,
5571 you could have to rebuild or re-download packages. @xref{Invoking guix
5572 gc}, for more on GC roots.
5574 @item --expression=@var{expr}
5575 @itemx -e @var{expr}
5576 Create an environment for the package or list of packages that
5577 @var{expr} evaluates to.
5579 For example, running:
5582 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5585 starts a shell with the environment for this specific variant of the
5591 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5594 starts a shell with all the base system packages available.
5596 The above commands only use the default output of the given packages.
5597 To select other outputs, two element tuples can be specified:
5600 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5603 @item --load=@var{file}
5604 @itemx -l @var{file}
5605 Create an environment for the package or list of packages that the code
5606 within @var{file} evaluates to.
5608 As an example, @var{file} might contain a definition like this
5609 (@pxref{Defining Packages}):
5612 @verbatiminclude environment-gdb.scm
5615 @item --manifest=@var{file}
5616 @itemx -m @var{file}
5617 Create an environment for the packages contained in the manifest object
5618 returned by the Scheme code in @var{file}. This option can be repeated
5619 several times, in which case the manifests are concatenated.
5621 This is similar to the same-named option in @command{guix package}
5622 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5626 Include all specified packages in the resulting environment, as if an
5627 @i{ad hoc} package were defined with them as inputs. This option is
5628 useful for quickly creating an environment without having to write a
5629 package expression to contain the desired inputs.
5631 For instance, the command:
5634 guix environment --ad-hoc guile guile-sdl -- guile
5637 runs @command{guile} in an environment where Guile and Guile-SDL are
5640 Note that this example implicitly asks for the default output of
5641 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5642 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5643 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5645 This option may be composed with the default behavior of @command{guix
5646 environment}. Packages appearing before @option{--ad-hoc} are
5647 interpreted as packages whose dependencies will be added to the
5648 environment, the default behavior. Packages appearing after are
5649 interpreted as packages that will be added to the environment directly.
5652 Unset existing environment variables when building the new environment, except
5653 those specified with @option{--preserve} (see below). This has the effect of
5654 creating an environment in which search paths only contain package inputs.
5656 @item --preserve=@var{regexp}
5657 @itemx -E @var{regexp}
5658 When used alongside @option{--pure}, preserve the environment variables
5659 matching @var{regexp}---in other words, put them on a ``white list'' of
5660 environment variables that must be preserved. This option can be repeated
5664 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5668 This example runs @command{mpirun} in a context where the only environment
5669 variables defined are @env{PATH}, environment variables whose name starts
5670 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5673 @item --search-paths
5674 Display the environment variable definitions that make up the
5677 @item --system=@var{system}
5678 @itemx -s @var{system}
5679 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5684 Run @var{command} within an isolated container. The current working
5685 directory outside the container is mapped inside the container.
5686 Additionally, unless overridden with @option{--user}, a dummy home
5687 directory is created that matches the current user's home directory, and
5688 @file{/etc/passwd} is configured accordingly.
5690 The spawned process runs as the current user outside the container. Inside
5691 the container, it has the same UID and GID as the current user, unless
5692 @option{--user} is passed (see below).
5696 For containers, share the network namespace with the host system.
5697 Containers created without this flag only have access to the loopback
5700 @item --link-profile
5702 For containers, link the environment profile to @file{~/.guix-profile}
5703 within the container and set @code{GUIX_ENVIRONMENT} to that.
5704 This is equivalent to making @file{~/.guix-profile} a symlink to the
5705 actual profile within the container.
5706 Linking will fail and abort the environment if the directory already
5707 exists, which will certainly be the case if @command{guix environment}
5708 was invoked in the user's home directory.
5710 Certain packages are configured to look in @file{~/.guix-profile} for
5711 configuration files and data;@footnote{For example, the
5712 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5713 for additional fonts.} @option{--link-profile} allows these programs to
5714 behave as expected within the environment.
5716 @item --user=@var{user}
5717 @itemx -u @var{user}
5718 For containers, use the username @var{user} in place of the current
5719 user. The generated @file{/etc/passwd} entry within the container will
5720 contain the name @var{user}, the home directory will be
5721 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5722 the UID and GID inside the container are 1000. @var{user}
5723 need not exist on the system.
5725 Additionally, any shared or exposed path (see @option{--share} and
5726 @option{--expose} respectively) whose target is within the current user's
5727 home directory will be remapped relative to @file{/home/USER}; this
5728 includes the automatic mapping of the current working directory.
5731 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5733 guix environment --container --user=foo \
5734 --expose=$HOME/test \
5735 --expose=/tmp/target=$HOME/target
5738 While this will limit the leaking of user identity through home paths
5739 and each of the user fields, this is only one useful component of a
5740 broader privacy/anonymity solution---not one in and of itself.
5743 For containers, the default behavior is to share the current working
5744 directory with the isolated container and immediately change to that
5745 directory within the container. If this is undesirable,
5746 @option{--no-cwd} will cause the current working directory to @emph{not}
5747 be automatically shared and will change to the user's home directory
5748 within the container instead. See also @option{--user}.
5750 @item --expose=@var{source}[=@var{target}]
5751 @itemx --share=@var{source}[=@var{target}]
5752 For containers, @option{--expose} (resp. @option{--share}) exposes the
5753 file system @var{source} from the host system as the read-only
5754 (resp. writable) file system @var{target} within the container. If
5755 @var{target} is not specified, @var{source} is used as the target mount
5756 point in the container.
5758 The example below spawns a Guile REPL in a container in which the user's
5759 home directory is accessible read-only via the @file{/exchange}
5763 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5768 @command{guix environment}
5769 also supports all of the common build options that @command{guix
5770 build} supports (@pxref{Common Build Options}) as well as package
5771 transformation options (@pxref{Package Transformation Options}).
5773 @node Invoking guix pack
5774 @section Invoking @command{guix pack}
5776 Occasionally you want to pass software to people who are not (yet!)
5777 lucky enough to be using Guix. You'd tell them to run @command{guix
5778 package -i @var{something}}, but that's not possible in this case. This
5779 is where @command{guix pack} comes in.
5782 If you are looking for ways to exchange binaries among machines that
5783 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5784 publish}, and @ref{Invoking guix archive}.
5789 @cindex application bundle
5790 @cindex software bundle
5791 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5792 @dfn{software bundle}: it creates a tarball or some other archive
5793 containing the binaries of the software you're interested in, and all
5794 its dependencies. The resulting archive can be used on any machine that
5795 does not have Guix, and people can run the exact same binaries as those
5796 you have with Guix. The pack itself is created in a bit-reproducible
5797 fashion, so anyone can verify that it really contains the build results
5798 that you pretend to be shipping.
5800 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5801 their dependencies, you can run:
5804 $ guix pack guile emacs geiser
5806 /gnu/store/@dots{}-pack.tar.gz
5809 The result here is a tarball containing a @file{/gnu/store} directory
5810 with all the relevant packages. The resulting tarball contains a
5811 @dfn{profile} with the three packages of interest; the profile is the
5812 same as would be created by @command{guix package -i}. It is this
5813 mechanism that is used to create Guix's own standalone binary tarball
5814 (@pxref{Binary Installation}).
5816 Users of this pack would have to run
5817 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5818 find inconvenient. To work around it, you can create, say, a
5819 @file{/opt/gnu/bin} symlink to the profile:
5822 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5826 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5828 @cindex relocatable binaries, with @command{guix pack}
5829 What if the recipient of your pack does not have root privileges on
5830 their machine, and thus cannot unpack it in the root file system? In
5831 that case, you will want to use the @option{--relocatable} option (see
5832 below). This option produces @dfn{relocatable binaries}, meaning they
5833 they can be placed anywhere in the file system hierarchy: in the example
5834 above, users can unpack your tarball in their home directory and
5835 directly run @file{./opt/gnu/bin/guile}.
5837 @cindex Docker, build an image with guix pack
5838 Alternatively, you can produce a pack in the Docker image format using
5839 the following command:
5842 guix pack -f docker -S /bin=bin guile guile-readline
5846 The result is a tarball that can be passed to the @command{docker load}
5847 command, followed by @code{docker run}:
5850 docker load < @var{file}
5851 docker run -ti guile-guile-readline /bin/guile
5855 where @var{file} is the image returned by @var{guix pack}, and
5856 @code{guile-guile-readline} is its ``image tag''. See the
5857 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5858 documentation} for more information.
5860 @cindex Singularity, build an image with guix pack
5861 @cindex SquashFS, build an image with guix pack
5862 Yet another option is to produce a SquashFS image with the following
5866 guix pack -f squashfs bash guile emacs geiser
5870 The result is a SquashFS file system image that can either be mounted or
5871 directly be used as a file system container image with the
5872 @uref{https://www.sylabs.io/docs/, Singularity container execution
5873 environment}, using commands like @command{singularity shell} or
5874 @command{singularity exec}.
5876 Several command-line options allow you to customize your pack:
5879 @item --format=@var{format}
5880 @itemx -f @var{format}
5881 Produce a pack in the given @var{format}.
5883 The available formats are:
5887 This is the default format. It produces a tarball containing all the
5888 specified binaries and symlinks.
5891 This produces a tarball that follows the
5892 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
5893 Docker Image Specification}. The ``repository name'' as it appears in
5894 the output of the @command{docker images} command is computed from
5895 package names passed on the command line or in the manifest file.
5898 This produces a SquashFS image containing all the specified binaries and
5899 symlinks, as well as empty mount points for virtual file systems like
5903 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
5904 For that reason, @command{guix pack -f squashfs} always implies @code{-S
5905 /bin=bin}. Thus, your @command{guix pack} invocation must always start
5906 with something like:
5909 guix pack -f squashfs bash @dots{}
5912 If you forget the @code{bash} (or similar) package, @command{singularity
5913 run} and @command{singularity exec} will fail with an unhelpful ``no
5914 such file or directory'' message.
5918 @cindex relocatable binaries
5921 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
5922 anywhere in the file system hierarchy and run from there.
5924 When this option is passed once, the resulting binaries require support for
5925 @dfn{user namespaces} in the kernel Linux; when passed
5926 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
5927 PRoot support, can be thought of as the abbreviation of ``Really
5928 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
5929 other techniques if user namespaces are unavailable, and essentially
5930 work anywhere---see below for the implications.
5932 For example, if you create a pack containing Bash with:
5935 guix pack -RR -S /mybin=bin bash
5939 ...@: you can copy that pack to a machine that lacks Guix, and from your
5940 home directory as a normal user, run:
5948 In that shell, if you type @code{ls /gnu/store}, you'll notice that
5949 @file{/gnu/store} shows up and contains all the dependencies of
5950 @code{bash}, even though the machine actually lacks @file{/gnu/store}
5951 altogether! That is probably the simplest way to deploy Guix-built
5952 software on a non-Guix machine.
5955 By default, relocatable binaries rely on the @dfn{user namespace} feature of
5956 the kernel Linux, which allows unprivileged users to mount or change root.
5957 Old versions of Linux did not support it, and some GNU/Linux distributions
5960 To produce relocatable binaries that work even in the absence of user
5961 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
5962 case, binaries will try user namespace support and fall back to another
5963 @dfn{execution engine} if user namespaces are not supported. The
5964 following execution engines are supported:
5968 Try user namespaces and fall back to PRoot if user namespaces are not
5969 supported (see below).
5972 Try user namespaces and fall back to Fakechroot if user namespaces are
5973 not supported (see below).
5976 Run the program through user namespaces and abort if they are not
5980 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
5981 provides the necessary
5982 support for file system virtualization. It achieves that by using the
5983 @code{ptrace} system call on the running program. This approach has the
5984 advantage to work without requiring special kernel support, but it incurs
5985 run-time overhead every time a system call is made.
5988 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
5989 Fakechroot} virtualizes file system accesses by intercepting calls to C
5990 library functions such as @code{open}, @code{stat}, @code{exec}, and so
5991 on. Unlike PRoot, it incurs very little overhead. However, it does not
5992 always work: for example, some file system accesses made from within the
5993 C library are not intercepted, and file system accesses made @i{via}
5994 direct syscalls are not intercepted either, leading to erratic behavior.
5997 @vindex GUIX_EXECUTION_ENGINE
5998 When running a wrapped program, you can explicitly request one of the
5999 execution engines listed above by setting the
6000 @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
6003 @cindex entry point, for Docker images
6004 @item --entry-point=@var{command}
6005 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
6006 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
6007 support it. @var{command} must be relative to the profile contained in the
6010 The entry point specifies the command that tools like @code{docker run} or
6011 @code{singularity run} automatically start by default. For example, you can
6015 guix pack -f docker --entry-point=bin/guile guile
6018 The resulting pack can easily be loaded and @code{docker run} with no extra
6019 arguments will spawn @code{bin/guile}:
6022 docker load -i pack.tar.gz
6023 docker run @var{image-id}
6026 @item --expression=@var{expr}
6027 @itemx -e @var{expr}
6028 Consider the package @var{expr} evaluates to.
6030 This has the same purpose as the same-named option in @command{guix
6031 build} (@pxref{Additional Build Options, @option{--expression} in
6032 @command{guix build}}).
6034 @item --manifest=@var{file}
6035 @itemx -m @var{file}
6036 Use the packages contained in the manifest object returned by the Scheme
6037 code in @var{file}. This option can be repeated several times, in which
6038 case the manifests are concatenated.
6040 This has a similar purpose as the same-named option in @command{guix
6041 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
6042 same manifest files. It allows you to define a collection of packages
6043 once and use it both for creating profiles and for creating archives
6044 for use on machines that do not have Guix installed. Note that you can
6045 specify @emph{either} a manifest file @emph{or} a list of packages,
6048 @item --system=@var{system}
6049 @itemx -s @var{system}
6050 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6051 the system type of the build host.
6053 @item --target=@var{triplet}
6054 @cindex cross-compilation
6055 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6056 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
6057 configuration triplets,, autoconf, Autoconf}).
6059 @item --compression=@var{tool}
6060 @itemx -C @var{tool}
6061 Compress the resulting tarball using @var{tool}---one of @code{gzip},
6062 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
6065 @item --symlink=@var{spec}
6066 @itemx -S @var{spec}
6067 Add the symlinks specified by @var{spec} to the pack. This option can
6068 appear several times.
6070 @var{spec} has the form @code{@var{source}=@var{target}}, where
6071 @var{source} is the symlink that will be created and @var{target} is the
6074 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
6075 symlink pointing to the @file{bin} sub-directory of the profile.
6077 @item --save-provenance
6078 Save provenance information for the packages passed on the command line.
6079 Provenance information includes the URL and commit of the channels in use
6082 Provenance information is saved in the
6083 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
6084 usual package metadata---the name and version of each package, their
6085 propagated inputs, and so on. It is useful information to the recipient of
6086 the pack, who then knows how the pack was (supposedly) obtained.
6088 This option is not enabled by default because, like timestamps, provenance
6089 information contributes nothing to the build process. In other words, there
6090 is an infinity of channel URLs and commit IDs that can lead to the same pack.
6091 Recording such ``silent'' metadata in the output thus potentially breaks the
6092 source-to-binary bitwise reproducibility property.
6094 @item --root=@var{file}
6095 @itemx -r @var{file}
6096 @cindex garbage collector root, for packs
6097 Make @var{file} a symlink to the resulting pack, and register it as a garbage
6100 @item --localstatedir
6101 @itemx --profile-name=@var{name}
6102 Include the ``local state directory'', @file{/var/guix}, in the resulting
6103 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
6104 profile---by default @var{name} is @code{guix-profile}, which corresponds to
6105 @file{~root/.guix-profile}.
6107 @file{/var/guix} contains the store database (@pxref{The Store}) as well
6108 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
6109 the pack means that the store is ``complete'' and manageable by Guix;
6110 not providing it pack means that the store is ``dead'': items cannot be
6111 added to it or removed from it after extraction of the pack.
6113 One use case for this is the Guix self-contained binary tarball
6114 (@pxref{Binary Installation}).
6118 Print the name of the derivation that builds the pack.
6121 Use the bootstrap binaries to build the pack. This option is only
6122 useful to Guix developers.
6125 In addition, @command{guix pack} supports all the common build options
6126 (@pxref{Common Build Options}) and all the package transformation
6127 options (@pxref{Package Transformation Options}).
6130 @node The GCC toolchain
6131 @section The GCC toolchain
6135 @cindex linker wrapper
6136 @cindex toolchain, for C development
6137 @cindex toolchain, for Fortran development
6139 If you need a complete toolchain for compiling and linking C or C++
6140 source code, use the @code{gcc-toolchain} package. This package
6141 provides a complete GCC toolchain for C/C++ development, including GCC
6142 itself, the GNU C Library (headers and binaries, plus debugging symbols
6143 in the @code{debug} output), Binutils, and a linker wrapper.
6145 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
6146 passed to the linker, add corresponding @code{-rpath} arguments, and
6147 invoke the actual linker with this new set of arguments. You can instruct the
6148 wrapper to refuse to link against libraries not in the store by setting the
6149 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
6151 The package @code{gfortran-toolchain} provides a complete GCC toolchain
6152 for Fortran development. For other languages, please use
6153 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
6156 @node Invoking guix git authenticate
6157 @section Invoking @command{guix git authenticate}
6159 The @command{guix git authenticate} command authenticates a Git checkout
6160 following the same rule as for channels (@pxref{channel-authentication,
6161 channel authentication}). That is, starting from a given commit, it
6162 ensures that all subsequent commits are signed by an OpenPGP key whose
6163 fingerprint appears in the @file{.guix-authorizations} file of its
6166 You will find this command useful if you maintain a channel. But in
6167 fact, this authentication mechanism is useful in a broader context, so
6168 you might want to use it for Git repositories that have nothing to do
6171 The general syntax is:
6174 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
6177 By default, this command authenticates the Git checkout in the current
6178 directory; it outputs nothing and exits with exit code zero on success
6179 and non-zero on failure. @var{commit} above denotes the first commit
6180 where authentication takes place, and @var{signer} is the OpenPGP
6181 fingerprint of public key used to sign @var{commit}. Together, they
6182 form a ``channel introduction'' (@pxref{channel-authentication, channel
6183 introduction}). The options below allow you to fine-tune the process.
6186 @item --repository=@var{directory}
6187 @itemx -r @var{directory}
6188 Open the Git repository in @var{directory} instead of the current
6191 @item --keyring=@var{reference}
6192 @itemx -k @var{reference}
6193 Load OpenPGP keyring from @var{reference}, the reference of a branch
6194 such as @code{origin/keyring} or @code{my-keyring}. The branch must
6195 contain OpenPGP public keys in @file{.key} files, either in binary form
6196 or ``ASCII-armored''. By default the keyring is loaded from the branch
6197 named @code{keyring}.
6200 Display commit signing statistics upon completion.
6202 @item --cache-key=@var{key}
6203 Previously-authenticated commits are cached in a file under
6204 @file{~/.cache/guix/authentication}. This option forces the cache to be
6205 stored in file @var{key} in that directory.
6207 @item --historical-authorizations=@var{file}
6208 By default, any commit whose parent commit(s) lack the
6209 @file{.guix-authorizations} file is considered inauthentic. In
6210 contrast, this option considers the authorizations in @var{file} for any
6211 commit that lacks @file{.guix-authorizations}. The format of @var{file}
6212 is the same as that of @file{.guix-authorizations}
6213 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
6217 @c *********************************************************************
6218 @node Programming Interface
6219 @chapter Programming Interface
6221 GNU Guix provides several Scheme programming interfaces (APIs) to
6222 define, build, and query packages. The first interface allows users to
6223 write high-level package definitions. These definitions refer to
6224 familiar packaging concepts, such as the name and version of a package,
6225 its build system, and its dependencies. These definitions can then be
6226 turned into concrete build actions.
6228 Build actions are performed by the Guix daemon, on behalf of users. In a
6229 standard setup, the daemon has write access to the store---the
6230 @file{/gnu/store} directory---whereas users do not. The recommended
6231 setup also has the daemon perform builds in chroots, under specific
6232 build users, to minimize interference with the rest of the system.
6235 Lower-level APIs are available to interact with the daemon and the
6236 store. To instruct the daemon to perform a build action, users actually
6237 provide it with a @dfn{derivation}. A derivation is a low-level
6238 representation of the build actions to be taken, and the environment in
6239 which they should occur---derivations are to package definitions what
6240 assembly is to C programs. The term ``derivation'' comes from the fact
6241 that build results @emph{derive} from them.
6243 This chapter describes all these APIs in turn, starting from high-level
6244 package definitions.
6247 * Package Modules:: Packages from the programmer's viewpoint.
6248 * Defining Packages:: Defining new packages.
6249 * Defining Package Variants:: Customizing packages.
6250 * Build Systems:: Specifying how packages are built.
6251 * Build Phases:: Phases of the build process of a package.
6252 * Build Utilities:: Helpers for your package definitions and more.
6253 * The Store:: Manipulating the package store.
6254 * Derivations:: Low-level interface to package derivations.
6255 * The Store Monad:: Purely functional interface to the store.
6256 * G-Expressions:: Manipulating build expressions.
6257 * Invoking guix repl:: Programming Guix in Guile
6260 @node Package Modules
6261 @section Package Modules
6263 From a programming viewpoint, the package definitions of the
6264 GNU distribution are provided by Guile modules in the @code{(gnu packages
6265 @dots{})} name space@footnote{Note that packages under the @code{(gnu
6266 packages @dots{})} module name space are not necessarily ``GNU
6267 packages''. This module naming scheme follows the usual Guile module
6268 naming convention: @code{gnu} means that these modules are distributed
6269 as part of the GNU system, and @code{packages} identifies modules that
6270 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
6271 Reference Manual}). For instance, the @code{(gnu packages emacs)}
6272 module exports a variable named @code{emacs}, which is bound to a
6273 @code{<package>} object (@pxref{Defining Packages}).
6275 The @code{(gnu packages @dots{})} module name space is
6276 automatically scanned for packages by the command-line tools. For
6277 instance, when running @code{guix install emacs}, all the @code{(gnu
6278 packages @dots{})} modules are scanned until one that exports a package
6279 object whose name is @code{emacs} is found. This package search
6280 facility is implemented in the @code{(gnu packages)} module.
6282 @cindex customization, of packages
6283 @cindex package module search path
6284 Users can store package definitions in modules with different
6285 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
6286 name and module name must match. For instance, the @code{(my-packages
6287 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
6288 relative to the load path specified with @option{--load-path} or
6289 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
6290 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
6291 these package definitions visible to the user interfaces:
6295 By adding the directory containing your package modules to the search path
6296 with the @code{-L} flag of @command{guix package} and other commands
6297 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6298 environment variable described below.
6301 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6302 pulls from it. A channel is essentially a Git repository containing package
6303 modules. @xref{Channels}, for more information on how to define and use
6307 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6309 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6310 This is a colon-separated list of directories to search for additional
6311 package modules. Directories listed in this variable take precedence
6312 over the own modules of the distribution.
6315 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6316 each package is built based solely on other packages in the
6317 distribution. The root of this dependency graph is a small set of
6318 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6319 bootstrap)} module. For more information on bootstrapping,
6320 @pxref{Bootstrapping}.
6322 @node Defining Packages
6323 @section Defining Packages
6325 The high-level interface to package definitions is implemented in the
6326 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6327 example, the package definition, or @dfn{recipe}, for the GNU Hello
6328 package looks like this:
6331 (define-module (gnu packages hello)
6332 #:use-module (guix packages)
6333 #:use-module (guix download)
6334 #:use-module (guix build-system gnu)
6335 #:use-module (guix licenses)
6336 #:use-module (gnu packages gawk))
6338 (define-public hello
6344 (uri (string-append "mirror://gnu/hello/hello-" version
6348 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6349 (build-system gnu-build-system)
6350 (arguments '(#:configure-flags '("--enable-silent-rules")))
6351 (inputs `(("gawk" ,gawk)))
6352 (synopsis "Hello, GNU world: An example GNU package")
6353 (description "Guess what GNU Hello prints!")
6354 (home-page "https://www.gnu.org/software/hello/")
6359 Without being a Scheme expert, the reader may have guessed the meaning
6360 of the various fields here. This expression binds the variable
6361 @code{hello} to a @code{<package>} object, which is essentially a record
6362 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6363 This package object can be inspected using procedures found in the
6364 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6365 returns---surprise!---@code{"hello"}.
6367 With luck, you may be able to import part or all of the definition of
6368 the package you are interested in from another repository, using the
6369 @code{guix import} command (@pxref{Invoking guix import}).
6371 In the example above, @code{hello} is defined in a module of its own,
6372 @code{(gnu packages hello)}. Technically, this is not strictly
6373 necessary, but it is convenient to do so: all the packages defined in
6374 modules under @code{(gnu packages @dots{})} are automatically known to
6375 the command-line tools (@pxref{Package Modules}).
6377 There are a few points worth noting in the above package definition:
6381 The @code{source} field of the package is an @code{<origin>} object
6382 (@pxref{origin Reference}, for the complete reference).
6383 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6384 meaning that the source is a file to be downloaded over FTP or HTTP.
6386 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6387 the GNU mirrors defined in @code{(guix download)}.
6389 The @code{sha256} field specifies the expected SHA256 hash of the file
6390 being downloaded. It is mandatory, and allows Guix to check the
6391 integrity of the file. The @code{(base32 @dots{})} form introduces the
6392 base32 representation of the hash. You can obtain this information with
6393 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6394 hash} (@pxref{Invoking guix hash}).
6397 When needed, the @code{origin} form can also have a @code{patches} field
6398 listing patches to be applied, and a @code{snippet} field giving a
6399 Scheme expression to modify the source code.
6402 @cindex GNU Build System
6403 The @code{build-system} field specifies the procedure to build the
6404 package (@pxref{Build Systems}). Here, @code{gnu-build-system}
6405 represents the familiar GNU Build System, where packages may be
6406 configured, built, and installed with the usual @code{./configure &&
6407 make && make check && make install} command sequence.
6409 When you start packaging non-trivial software, you may need tools to
6410 manipulate those build phases, manipulate files, and so on. @xref{Build
6411 Utilities}, for more on this.
6414 The @code{arguments} field specifies options for the build system
6415 (@pxref{Build Systems}). Here it is interpreted by
6416 @code{gnu-build-system} as a request run @file{configure} with the
6417 @option{--enable-silent-rules} flag.
6423 What about these quote (@code{'}) characters? They are Scheme syntax to
6424 introduce a literal list; @code{'} is synonymous with @code{quote}.
6425 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6426 for details. Here the value of the @code{arguments} field is a list of
6427 arguments passed to the build system down the road, as with @code{apply}
6428 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6431 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6432 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6433 @code{#:configure-flags} is a keyword used to pass a keyword argument
6434 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6438 The @code{inputs} field specifies inputs to the build process---i.e.,
6439 build-time or run-time dependencies of the package. Here, we define an
6440 input called @code{"gawk"} whose value is that of the @code{gawk}
6441 variable; @code{gawk} is itself bound to a @code{<package>} object.
6443 @cindex backquote (quasiquote)
6446 @cindex comma (unquote)
6450 @findex unquote-splicing
6451 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6452 us to introduce a literal list in the @code{inputs} field, while
6453 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6454 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6457 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6458 be specified as inputs here. Instead, @code{gnu-build-system} takes care
6459 of ensuring that they are present (@pxref{Build Systems}).
6461 However, any other dependencies need to be specified in the
6462 @code{inputs} field. Any dependency not specified here will simply be
6463 unavailable to the build process, possibly leading to a build failure.
6466 @xref{package Reference}, for a full description of possible fields.
6468 Once a package definition is in place, the
6469 package may actually be built using the @code{guix build} command-line
6470 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6471 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6472 package definition using the @command{guix edit} command
6473 (@pxref{Invoking guix edit}).
6474 @xref{Packaging Guidelines}, for
6475 more information on how to test package definitions, and
6476 @ref{Invoking guix lint}, for information on how to check a definition
6477 for style conformance.
6478 @vindex GUIX_PACKAGE_PATH
6479 Lastly, @pxref{Channels}, for information
6480 on how to extend the distribution by adding your own package definitions
6483 Finally, updating the package definition to a new upstream version
6484 can be partly automated by the @command{guix refresh} command
6485 (@pxref{Invoking guix refresh}).
6487 Behind the scenes, a derivation corresponding to the @code{<package>}
6488 object is first computed by the @code{package-derivation} procedure.
6489 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6490 The build actions it prescribes may then be realized by using the
6491 @code{build-derivations} procedure (@pxref{The Store}).
6493 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6494 Return the @code{<derivation>} object of @var{package} for @var{system}
6495 (@pxref{Derivations}).
6497 @var{package} must be a valid @code{<package>} object, and @var{system}
6498 must be a string denoting the target system type---e.g.,
6499 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6500 must be a connection to the daemon, which operates on the store
6501 (@pxref{The Store}).
6505 @cindex cross-compilation
6506 Similarly, it is possible to compute a derivation that cross-builds a
6507 package for some other system:
6509 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6510 @var{package} @var{target} [@var{system}]
6511 Return the @code{<derivation>} object of @var{package} cross-built from
6512 @var{system} to @var{target}.
6514 @var{target} must be a valid GNU triplet denoting the target hardware
6515 and operating system, such as @code{"aarch64-linux-gnu"}
6516 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6519 Once you have package definitions, you can easily define @emph{variants}
6520 of those packages. @xref{Defining Package Variants}, for more on that.
6523 * package Reference:: The package data type.
6524 * origin Reference:: The origin data type.
6528 @node package Reference
6529 @subsection @code{package} Reference
6531 This section summarizes all the options available in @code{package}
6532 declarations (@pxref{Defining Packages}).
6534 @deftp {Data Type} package
6535 This is the data type representing a package recipe.
6539 The name of the package, as a string.
6541 @item @code{version}
6542 The version of the package, as a string.
6545 An object telling how the source code for the package should be
6546 acquired. Most of the time, this is an @code{origin} object, which
6547 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6548 can also be any other ``file-like'' object such as a @code{local-file},
6549 which denotes a file from the local file system (@pxref{G-Expressions,
6550 @code{local-file}}).
6552 @item @code{build-system}
6553 The build system that should be used to build the package (@pxref{Build
6556 @item @code{arguments} (default: @code{'()})
6557 The arguments that should be passed to the build system. This is a
6558 list, typically containing sequential keyword-value pairs.
6560 @item @code{inputs} (default: @code{'()})
6561 @itemx @code{native-inputs} (default: @code{'()})
6562 @itemx @code{propagated-inputs} (default: @code{'()})
6563 @cindex inputs, of packages
6564 These fields list dependencies of the package. Each one is a list of
6565 tuples, where each tuple has a label for the input (a string) as its
6566 first element, a package, origin, or derivation as its second element,
6567 and optionally the name of the output thereof that should be used, which
6568 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6569 more on package outputs). For example, the list below specifies three
6573 `(("libffi" ,libffi)
6574 ("libunistring" ,libunistring)
6575 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6578 @cindex cross compilation, package dependencies
6579 The distinction between @code{native-inputs} and @code{inputs} is
6580 necessary when considering cross-compilation. When cross-compiling,
6581 dependencies listed in @code{inputs} are built for the @emph{target}
6582 architecture; conversely, dependencies listed in @code{native-inputs}
6583 are built for the architecture of the @emph{build} machine.
6585 @code{native-inputs} is typically used to list tools needed at
6586 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6587 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6588 this area (@pxref{Invoking guix lint}).
6590 @anchor{package-propagated-inputs}
6591 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6592 specified packages will be automatically installed to profiles
6593 (@pxref{Features, the role of profiles in Guix}) alongside the package
6594 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6595 package}}, for information on how @command{guix package} deals with
6598 For example this is necessary when packaging a C/C++ library that needs
6599 headers of another library to compile, or when a pkg-config file refers
6600 to another one @i{via} its @code{Requires} field.
6602 Another example where @code{propagated-inputs} is useful is for languages
6603 that lack a facility to record the run-time search path akin to the
6604 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6605 more. When packaging libraries written in those languages, ensure they
6606 can find library code they depend on at run time by listing run-time
6607 dependencies in @code{propagated-inputs} rather than @code{inputs}.
6609 @item @code{outputs} (default: @code{'("out")})
6610 The list of output names of the package. @xref{Packages with Multiple
6611 Outputs}, for typical uses of additional outputs.
6613 @item @code{native-search-paths} (default: @code{'()})
6614 @itemx @code{search-paths} (default: @code{'()})
6615 A list of @code{search-path-specification} objects describing
6616 search-path environment variables honored by the package.
6618 @item @code{replacement} (default: @code{#f})
6619 This must be either @code{#f} or a package object that will be used as a
6620 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6623 @item @code{synopsis}
6624 A one-line description of the package.
6626 @item @code{description}
6627 A more elaborate description of the package.
6629 @item @code{license}
6630 @cindex license, of packages
6631 The license of the package; a value from @code{(guix licenses)},
6632 or a list of such values.
6634 @item @code{home-page}
6635 The URL to the home-page of the package, as a string.
6637 @item @code{supported-systems} (default: @code{%supported-systems})
6638 The list of systems supported by the package, as strings of the form
6639 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6641 @item @code{location} (default: source location of the @code{package} form)
6642 The source location of the package. It is useful to override this when
6643 inheriting from another package, in which case this field is not
6644 automatically corrected.
6648 @deffn {Scheme Syntax} this-package
6649 When used in the @emph{lexical scope} of a package field definition, this
6650 identifier resolves to the package being defined.
6652 The example below shows how to add a package as a native input of itself when
6660 ;; When cross-compiled, Guile, for example, depends on
6661 ;; a native version of itself. Add it here.
6662 (native-inputs (if (%current-target-system)
6663 `(("self" ,this-package))
6667 It is an error to refer to @code{this-package} outside a package definition.
6670 Because packages are regular Scheme objects that capture a complete
6671 dependency graph and associated build procedures, it is often useful to
6672 write procedures that take a package and return a modified version
6673 thereof according to some parameters. Below are a few examples.
6675 @cindex tool chain, choosing a package's tool chain
6676 @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
6677 Return a variant of @var{package} that uses @var{toolchain} instead of
6678 the default GNU C/C++ toolchain. @var{toolchain} must be a list of
6679 inputs (label/package tuples) providing equivalent functionality, such
6680 as the @code{gcc-toolchain} package.
6682 The example below returns a variant of the @code{hello} package built
6683 with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
6684 GNU C Library) instead of the default tool chain:
6687 (let ((toolchain (specification->package "gcc-toolchain@@10")))
6688 (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
6691 The build tool chain is part of the @dfn{implicit inputs} of
6692 packages---it's usually not listed as part of the various ``inputs''
6693 fields and is instead pulled in by the build system. Consequently, this
6694 procedure works by changing the build system of @var{package} so that it
6695 pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
6696 for more on build systems.
6699 @node origin Reference
6700 @subsection @code{origin} Reference
6702 This section documents @dfn{origins}. An @code{origin} declaration
6703 specifies data that must be ``produced''---downloaded, usually---and
6704 whose content hash is known in advance. Origins are primarily used to
6705 represent the source code of packages (@pxref{Defining Packages}). For
6706 that reason, the @code{origin} form allows you to declare patches to
6707 apply to the original source code as well as code snippets to modify it.
6709 @deftp {Data Type} origin
6710 This is the data type representing a source code origin.
6714 An object containing the URI of the source. The object type depends on
6715 the @code{method} (see below). For example, when using the
6716 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6717 values are: a URL represented as a string, or a list thereof.
6719 @cindex fixed-output derivations, for download
6721 A monadic procedure that handles the given URI. The procedure must
6722 accept at least three arguments: the value of the @code{uri} field and
6723 the hash algorithm and hash value specified by the @code{hash} field.
6724 It must return a store item or a derivation in the store monad
6725 (@pxref{The Store Monad}); most methods return a fixed-output derivation
6726 (@pxref{Derivations}).
6728 Commonly used methods include @code{url-fetch}, which fetches data from
6729 a URL, and @code{git-fetch}, which fetches data from a Git repository
6733 A bytevector containing the SHA-256 hash of the source. This is
6734 equivalent to providing a @code{content-hash} SHA256 object in the
6735 @code{hash} field described below.
6738 The @code{content-hash} object of the source---see below for how to use
6739 @code{content-hash}.
6741 You can obtain this information using @code{guix download}
6742 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6745 @item @code{file-name} (default: @code{#f})
6746 The file name under which the source code should be saved. When this is
6747 @code{#f}, a sensible default value will be used in most cases. In case
6748 the source is fetched from a URL, the file name from the URL will be
6749 used. For version control checkouts, it is recommended to provide the
6750 file name explicitly because the default is not very descriptive.
6752 @item @code{patches} (default: @code{'()})
6753 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6754 file-like objects}) pointing to patches to be applied to the source.
6756 This list of patches must be unconditional. In particular, it cannot
6757 depend on the value of @code{%current-system} or
6758 @code{%current-target-system}.
6760 @item @code{snippet} (default: @code{#f})
6761 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6762 in the source directory. This is a convenient way to modify the source,
6763 sometimes more convenient than a patch.
6765 @item @code{patch-flags} (default: @code{'("-p1")})
6766 A list of command-line flags that should be passed to the @code{patch}
6769 @item @code{patch-inputs} (default: @code{#f})
6770 Input packages or derivations to the patching process. When this is
6771 @code{#f}, the usual set of inputs necessary for patching are provided,
6772 such as GNU@tie{}Patch.
6774 @item @code{modules} (default: @code{'()})
6775 A list of Guile modules that should be loaded during the patching
6776 process and while running the code in the @code{snippet} field.
6778 @item @code{patch-guile} (default: @code{#f})
6779 The Guile package that should be used in the patching process. When
6780 this is @code{#f}, a sensible default is used.
6784 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6785 Construct a content hash object for the given @var{algorithm}, and with
6786 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6787 it is @code{sha256}.
6789 @var{value} can be a literal string, in which case it is base32-decoded,
6790 or it can be a bytevector.
6792 The following forms are all equivalent:
6795 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6796 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6798 (content-hash (base32
6799 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6800 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6804 Technically, @code{content-hash} is currently implemented as a macro.
6805 It performs sanity checks at macro-expansion time, when possible, such
6806 as ensuring that @var{value} has the right size for @var{algorithm}.
6809 As we have seen above, how exactly the data an origin refers to is
6810 retrieved is determined by its @code{method} field. The @code{(guix
6811 download)} module provides the most common method, @code{url-fetch},
6814 @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
6815 [name] [#:executable? #f]
6816 Return a fixed-output derivation that fetches data from @var{url} (a
6817 string, or a list of strings denoting alternate URLs), which is expected
6818 to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
6819 the file name is the base name of URL; optionally, @var{name} can
6820 specify a different file name. When @var{executable?} is true, make the
6821 downloaded file executable.
6823 When one of the URL starts with @code{mirror://}, then its host part is
6824 interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
6826 Alternatively, when URL starts with @code{file://}, return the
6827 corresponding file name in the store.
6830 Likewise, the @code{(guix git-download)} module defines the
6831 @code{git-fetch} origin method, which fetches data from a Git version
6832 control repository, and the @code{git-reference} data type to describe
6833 the repository and revision to fetch.
6835 @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
6836 Return a fixed-output derivation that fetches @var{ref}, a
6837 @code{<git-reference>} object. The output is expected to have recursive
6838 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6839 the file name, or a generic name if @code{#f}.
6842 @deftp {Data Type} git-reference
6843 This data type represents a Git reference for @code{git-fetch} to
6848 The URL of the Git repository to clone.
6851 This string denotes either the commit to fetch (a hexadecimal string,
6852 either the full SHA1 commit or a ``short'' commit string; the latter is
6853 not recommended) or the tag to fetch.
6855 @item @code{recursive?} (default: @code{#f})
6856 This Boolean indicates whether to recursively fetch Git sub-modules.
6859 The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
6864 (url "https://git.savannah.gnu.org/git/hello.git")
6868 This is equivalent to the reference below, which explicitly names the
6873 (url "https://git.savannah.gnu.org/git/hello.git")
6874 (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
6878 For Mercurial repositories, the module @code{(guix hg-download)} defines
6879 the @code{hg-fetch} origin method and @code{hg-reference} data type for
6880 support of the Mercurial version control system.
6882 @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
6884 Return a fixed-output derivation that fetches @var{ref}, a
6885 @code{<hg-reference>} object. The output is expected to have recursive
6886 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6887 the file name, or a generic name if @code{#false}.
6890 @node Defining Package Variants
6891 @section Defining Package Variants
6893 @cindex customizing packages
6894 @cindex variants, of packages
6895 One of the nice things with Guix is that, given a package definition,
6896 you can easily @emph{derive} variants of that package---for a different
6897 upstream version, with different dependencies, different compilation
6898 options, and so on. Some of these custom packages can be defined
6899 straight from the command line (@pxref{Package Transformation Options}).
6900 This section describes how to define package variants in code. This can
6901 be useful in ``manifests'' (@pxref{profile-manifest,
6902 @option{--manifest}}) and in your own package collection
6903 (@pxref{Creating a Channel}), among others!
6905 @cindex inherit, for package definitions
6906 As discussed earlier, packages are first-class objects in the Scheme
6907 language. The @code{(guix packages)} module provides the @code{package}
6908 construct to define new package objects (@pxref{package Reference}).
6909 The easiest way to define a package variant is using the @code{inherit}
6910 keyword together with @code{package}. This allows you to inherit from a
6911 package definition while overriding the fields you want.
6913 For example, given the @code{hello} variable, which contains a
6914 definition for the current version of GNU@tie{}Hello, here's how you
6915 would define a variant for version 2.2 (released in 2006, it's
6919 (use-modules (gnu packages base)) ;for 'hello'
6927 (uri (string-append "mirror://gnu/hello/hello-" version
6931 "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
6934 The example above corresponds to what the @option{--with-source} package
6935 transformation option does. Essentially @code{hello-2.2} preserves all
6936 the fields of @code{hello}, except @code{version} and @code{source},
6937 which it overrides. Note that the original @code{hello} variable is
6938 still there, in the @code{(gnu packages base)} module, unchanged. When
6939 you define a custom package like this, you are really @emph{adding} a
6940 new package definition; the original one remains available.
6942 You can just as well define variants with a different set of
6943 dependencies than the original package. For example, the default
6944 @code{gdb} package depends on @code{guile}, but since that is an
6945 optional dependency, you can define a variant that removes that
6949 (use-modules (gnu packages gdb) ;for 'gdb'
6950 (srfi srfi-1)) ;for 'alist-delete'
6952 (define gdb-sans-guile
6955 (inputs (alist-delete "guile"
6956 (package-inputs gdb)))))
6959 The @code{alist-delete} call above removes the tuple from the
6960 @code{inputs} field that has @code{"guile"} as its first element
6961 (@pxref{SRFI-1 Association Lists,,, guile, GNU Guile Reference
6964 In some cases, you may find it useful to write functions
6965 (``procedures'', in Scheme parlance) that return a package based on some
6966 parameters. For example, consider the @code{luasocket} library for the
6967 Lua programming language. We want to create @code{luasocket} packages
6968 for major versions of Lua. One way to do that is to define a procedure
6969 that takes a Lua package and returns a @code{luasocket} package that
6973 (define (make-lua-socket name lua)
6974 ;; Return a luasocket package built with LUA.
6978 ;; several fields omitted
6981 (synopsis "Socket library for Lua")))
6983 (define-public lua5.1-socket
6984 (make-lua-socket "lua5.1-socket" lua-5.1))
6986 (define-public lua5.2-socket
6987 (make-lua-socket "lua5.2-socket" lua-5.2))
6990 Here we have defined packages @code{lua5.1-socket} and
6991 @code{lua5.2-socket} by calling @code{make-lua-socket} with different
6992 arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
6993 more info on procedures. Having top-level public definitions for these
6994 two packages means that they can be referred to from the command line
6995 (@pxref{Package Modules}).
6997 @cindex package transformations
6998 These are pretty simple package variants. As a convenience, the
6999 @code{(guix transformations)} module provides a high-level interface
7000 that directly maps to the more sophisticated package transformation
7001 options (@pxref{Package Transformation Options}):
7003 @deffn {Scheme Procedure} options->transformation @var{opts}
7004 Return a procedure that, when passed an object to build (package,
7005 derivation, etc.), applies the transformations specified by @var{opts} and returns
7006 the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
7009 ((with-branch . "guile-gcrypt=master")
7010 (without-tests . "libgcrypt"))
7013 Each symbol names a transformation and the corresponding string is an argument
7014 to that transformation.
7017 For instance, a manifest equivalent to this command:
7021 --with-branch=guile-gcrypt=master \
7022 --with-debug-info=zlib
7026 ... would look like this:
7029 (use-modules (guix transformations))
7032 ;; The package transformation procedure.
7033 (options->transformation
7034 '((with-branch . "guile-gcrypt=master")
7035 (with-debug-info . "zlib"))))
7038 (list (transform (specification->package "guix"))))
7041 @cindex input rewriting
7042 @cindex dependency graph rewriting
7043 The @code{options->transformation} procedure is convenient, but it's
7044 perhaps also not as flexible as you may like. How is it implemented?
7045 The astute reader probably noticed that most package transformation
7046 options go beyond the superficial changes shown in the first examples of
7047 this section: they involve @dfn{input rewriting}, whereby the dependency
7048 graph of a package is rewritten by replacing specific inputs by others.
7050 Dependency graph rewriting, for the purposes of swapping packages in the
7051 graph, is what the @code{package-input-rewriting} procedure in
7052 @code{(guix packages)} implements.
7054 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
7055 [@var{rewrite-name}] [#:deep? #t]
7056 Return a procedure that, when passed a package, replaces its direct and
7057 indirect dependencies, including implicit inputs when @var{deep?} is
7058 true, according to @var{replacements}. @var{replacements} is a list of
7059 package pairs; the first element of each pair is the package to replace,
7060 and the second one is the replacement.
7062 Optionally, @var{rewrite-name} is a one-argument procedure that takes
7063 the name of a package and returns its new name after rewrite.
7067 Consider this example:
7070 (define libressl-instead-of-openssl
7071 ;; This is a procedure to replace OPENSSL by LIBRESSL,
7073 (package-input-rewriting `((,openssl . ,libressl))))
7075 (define git-with-libressl
7076 (libressl-instead-of-openssl git))
7080 Here we first define a rewriting procedure that replaces @var{openssl}
7081 with @var{libressl}. Then we use it to define a @dfn{variant} of the
7082 @var{git} package that uses @var{libressl} instead of @var{openssl}.
7083 This is exactly what the @option{--with-input} command-line option does
7084 (@pxref{Package Transformation Options, @option{--with-input}}).
7086 The following variant of @code{package-input-rewriting} can match packages to
7087 be replaced by name rather than by identity.
7089 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
7090 Return a procedure that, given a package, applies the given
7091 @var{replacements} to all the package graph, including implicit inputs
7092 unless @var{deep?} is false. @var{replacements} is a list of
7093 spec/procedures pair; each spec is a package specification such as
7094 @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
7095 package and returns a replacement for that package.
7098 The example above could be rewritten this way:
7101 (define libressl-instead-of-openssl
7102 ;; Replace all the packages called "openssl" with LibreSSL.
7103 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
7106 The key difference here is that, this time, packages are matched by spec and
7107 not by identity. In other words, any package in the graph that is called
7108 @code{openssl} will be replaced.
7110 A more generic procedure to rewrite a package dependency graph is
7111 @code{package-mapping}: it supports arbitrary changes to nodes in the
7114 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
7115 Return a procedure that, given a package, applies @var{proc} to all the packages
7116 depended on and returns the resulting package. The procedure stops recursion
7117 when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
7118 applied to implicit inputs as well.
7123 @section Build Systems
7125 @cindex build system
7126 Each package definition specifies a @dfn{build system} and arguments for
7127 that build system (@pxref{Defining Packages}). This @code{build-system}
7128 field represents the build procedure of the package, as well as implicit
7129 dependencies of that build procedure.
7131 Build systems are @code{<build-system>} objects. The interface to
7132 create and manipulate them is provided by the @code{(guix build-system)}
7133 module, and actual build systems are exported by specific modules.
7135 @cindex bag (low-level package representation)
7136 Under the hood, build systems first compile package objects to
7137 @dfn{bags}. A @dfn{bag} is like a package, but with less
7138 ornamentation---in other words, a bag is a lower-level representation of
7139 a package, which includes all the inputs of that package, including some
7140 that were implicitly added by the build system. This intermediate
7141 representation is then compiled to a derivation (@pxref{Derivations}).
7142 The @code{package-with-c-toolchain} is an example of a way to change the
7143 implicit inputs that a package's build system pulls in (@pxref{package
7144 Reference, @code{package-with-c-toolchain}}).
7146 Build systems accept an optional list of @dfn{arguments}. In package
7147 definitions, these are passed @i{via} the @code{arguments} field
7148 (@pxref{Defining Packages}). They are typically keyword arguments
7149 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
7150 Guile Reference Manual}). The value of these arguments is usually
7151 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
7152 by the daemon (@pxref{Derivations}).
7154 The main build system is @code{gnu-build-system}, which implements the
7155 standard build procedure for GNU and many other packages. It
7156 is provided by the @code{(guix build-system gnu)} module.
7158 @defvr {Scheme Variable} gnu-build-system
7159 @code{gnu-build-system} represents the GNU Build System, and variants
7160 thereof (@pxref{Configuration, configuration and makefile conventions,,
7161 standards, GNU Coding Standards}).
7163 @cindex build phases
7164 In a nutshell, packages using it are configured, built, and installed with
7165 the usual @code{./configure && make && make check && make install}
7166 command sequence. In practice, a few additional steps are often needed.
7167 All these steps are split up in separate @dfn{phases},
7168 notably@footnote{Please see the @code{(guix build gnu-build-system)}
7169 modules for more details about the build phases.}:
7173 Unpack the source tarball, and change the current directory to the
7174 extracted source tree. If the source is actually a directory, copy it
7175 to the build tree, and enter that directory.
7177 @item patch-source-shebangs
7178 Patch shebangs encountered in source files so they refer to the right
7179 store file names. For instance, this changes @code{#!/bin/sh} to
7180 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
7183 Run the @file{configure} script with a number of default options, such
7184 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
7185 by the @code{#:configure-flags} argument.
7188 Run @code{make} with the list of flags specified with
7189 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
7190 (the default), build with @code{make -j}.
7193 Run @code{make check}, or some other target specified with
7194 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
7195 @code{#:parallel-tests?} argument is true (the default), run @code{make
7199 Run @code{make install} with the flags listed in @code{#:make-flags}.
7201 @item patch-shebangs
7202 Patch shebangs on the installed executable files.
7205 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
7206 is false), copying them to the @code{debug} output when available
7207 (@pxref{Installing Debugging Files}).
7210 @vindex %standard-phases
7211 The build-side module @code{(guix build gnu-build-system)} defines
7212 @code{%standard-phases} as the default list of build phases.
7213 @code{%standard-phases} is a list of symbol/procedure pairs, where the
7214 procedure implements the actual phase.
7216 @xref{Build Phases}, for more info on build phases and ways to customize
7219 In addition, this build system ensures that the ``standard'' environment
7220 for GNU packages is available. This includes tools such as GCC, libc,
7221 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
7222 build-system gnu)} module for a complete list). We call these the
7223 @dfn{implicit inputs} of a package, because package definitions do not
7224 have to mention them.
7227 Other @code{<build-system>} objects are defined to support other
7228 conventions and tools used by free software packages. They inherit most
7229 of @code{gnu-build-system}, and differ mainly in the set of inputs
7230 implicitly added to the build process, and in the list of phases
7231 executed. Some of these build systems are listed below.
7233 @defvr {Scheme Variable} ant-build-system
7234 This variable is exported by @code{(guix build-system ant)}. It
7235 implements the build procedure for Java packages that can be built with
7236 @url{https://ant.apache.org/, Ant build tool}.
7238 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
7239 provided by the @code{icedtea} package to the set of inputs. Different
7240 packages can be specified with the @code{#:ant} and @code{#:jdk}
7241 parameters, respectively.
7243 When the original package does not provide a suitable Ant build file,
7244 the parameter @code{#:jar-name} can be used to generate a minimal Ant
7245 build file @file{build.xml} with tasks to build the specified jar
7246 archive. In this case the parameter @code{#:source-dir} can be used to
7247 specify the source sub-directory, defaulting to ``src''.
7249 The @code{#:main-class} parameter can be used with the minimal ant
7250 buildfile to specify the main class of the resulting jar. This makes the
7251 jar file executable. The @code{#:test-include} parameter can be used to
7252 specify the list of junit tests to run. It defaults to
7253 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
7254 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
7255 because abstract classes cannot be run as tests.
7257 The parameter @code{#:build-target} can be used to specify the Ant task
7258 that should be run during the @code{build} phase. By default the
7259 ``jar'' task will be run.
7263 @defvr {Scheme Variable} android-ndk-build-system
7264 @cindex Android distribution
7265 @cindex Android NDK build system
7266 This variable is exported by @code{(guix build-system android-ndk)}. It
7267 implements a build procedure for Android NDK (native development kit)
7268 packages using a Guix-specific build process.
7270 The build system assumes that packages install their public interface
7271 (header) files to the subdirectory @file{include} of the @code{out} output and
7272 their libraries to the subdirectory @file{lib} the @code{out} output.
7274 It's also assumed that the union of all the dependencies of a package
7275 has no conflicting files.
7277 For the time being, cross-compilation is not supported - so right now
7278 the libraries and header files are assumed to be host tools.
7282 @defvr {Scheme Variable} asdf-build-system/source
7283 @defvrx {Scheme Variable} asdf-build-system/sbcl
7284 @defvrx {Scheme Variable} asdf-build-system/ecl
7286 These variables, exported by @code{(guix build-system asdf)}, implement
7287 build procedures for Common Lisp packages using
7288 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
7289 definition facility for Common Lisp programs and libraries.
7291 The @code{asdf-build-system/source} system installs the packages in
7292 source form, and can be loaded using any common lisp implementation, via
7293 ASDF. The others, such as @code{asdf-build-system/sbcl}, install binary
7294 systems in the format which a particular implementation understands.
7295 These build systems can also be used to produce executable programs, or
7296 lisp images which contain a set of packages pre-loaded.
7298 The build system uses naming conventions. For binary packages, the
7299 package name should be prefixed with the lisp implementation, such as
7300 @code{sbcl-} for @code{asdf-build-system/sbcl}.
7302 Additionally, the corresponding source package should be labeled using
7303 the same convention as python packages (see @ref{Python Modules}), using
7304 the @code{cl-} prefix.
7306 In order to create executable programs and images, the build-side
7307 procedures @code{build-program} and @code{build-image} can be used.
7308 They should be called in a build phase after the
7309 @code{create-asdf-configuration} phase, so that the system which was
7310 just built can be used within the resulting image. @code{build-program}
7311 requires a list of Common Lisp expressions to be passed as the
7312 @code{#:entry-program} argument.
7314 By default, all the @file{.asd} files present in the sources are read to
7315 find system definitions. The @code{#:asd-files} parameter can be used
7316 to specify the list of @file{.asd} files to read. Furthermore, if the
7317 package defines a system for its tests in a separate file, it will be
7318 loaded before the tests are run if it is specified by the
7319 @code{#:test-asd-file} parameter. If it is not set, the files
7320 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
7321 and @code{test.asd} will be tried if they exist.
7323 If for some reason the package must be named in a different way than the
7324 naming conventions suggest, or if several systems must be compiled, the
7325 @code{#:asd-systems} parameter can be used to specify the list of system
7330 @defvr {Scheme Variable} cargo-build-system
7331 @cindex Rust programming language
7332 @cindex Cargo (Rust build system)
7333 This variable is exported by @code{(guix build-system cargo)}. It
7334 supports builds of packages using Cargo, the build tool of the
7335 @uref{https://www.rust-lang.org, Rust programming language}.
7337 It adds @code{rustc} and @code{cargo} to the set of inputs.
7338 A different Rust package can be specified with the @code{#:rust} parameter.
7340 Regular cargo dependencies should be added to the package definition via the
7341 @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
7342 spec can be a package or a source definition. Note that the spec must
7343 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
7344 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
7345 should be added to the package definition via the
7346 @code{#:cargo-development-inputs} parameter.
7348 In its @code{configure} phase, this build system will make any source inputs
7349 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
7350 parameters available to cargo. It will also remove an included
7351 @code{Cargo.lock} file to be recreated by @code{cargo} during the
7352 @code{build} phase. The @code{install} phase installs the binaries
7353 defined by the crate.
7356 @defvr {Scheme Variable} chicken-build-system
7357 This variable is exported by @code{(guix build-system chicken)}. It
7358 builds @uref{https://call-cc.org/, CHICKEN Scheme} modules, also called
7359 ``eggs'' or ``extensions''. CHICKEN generates C source code, which then
7360 gets compiled by a C compiler, in this case GCC.
7362 This build system adds @code{chicken} to the package inputs, as well as
7363 the packages of @code{gnu-build-system}.
7365 The build system can't (yet) deduce the egg's name automatically, so just like
7366 with @code{go-build-system} and its @code{#:import-path}, you should define
7367 @code{#:egg-name} in the package's @code{arguments} field.
7369 For example, if you are packaging the @code{srfi-1} egg:
7372 (arguments '(#:egg-name "srfi-1"))
7375 Egg dependencies must be defined in @code{propagated-inputs}, not @code{inputs}
7376 because CHICKEN doesn't embed absolute references in compiled eggs.
7377 Test dependencies should go to @code{native-inputs}, as usual.
7380 @defvr {Scheme Variable} copy-build-system
7381 This variable is exported by @code{(guix build-system copy)}. It
7382 supports builds of simple packages that don't require much compiling,
7383 mostly just moving files around.
7385 It adds much of the @code{gnu-build-system} packages to the set of
7386 inputs. Because of this, the @code{copy-build-system} does not require
7387 all the boilerplate code often needed for the
7388 @code{trivial-build-system}.
7390 To further simplify the file installation process, an
7391 @code{#:install-plan} argument is exposed to let the packager specify
7392 which files go where. The install plan is a list of @code{(@var{source}
7393 @var{target} [@var{filters}])}. @var{filters} are optional.
7396 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
7398 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
7399 @item Otherwise install @var{source} as @var{target}.
7402 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
7403 the trailing slash of @var{target} is implied with the same meaning
7406 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
7407 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
7408 @code{#:exclude-regexp}, only select files are installed depending on
7409 the filters. Each filters is specified by a list of strings.
7411 @item With @code{#:include}, install all the files which the path suffix matches
7412 at least one of the elements in the given list.
7413 @item With @code{#:include-regexp}, install all the files which the
7414 subpaths match at least one of the regular expressions in the given
7416 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
7417 are the complement of their inclusion counterpart. Without @code{#:include} flags,
7418 install all files but those matching the exclusion filters.
7419 If both inclusions and exclusions are specified, the exclusions are done
7420 on top of the inclusions.
7423 In all cases, the paths relative to @var{source} are preserved within
7430 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
7431 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
7432 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
7433 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
7434 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
7435 @file{share/my-app/sub/file}.
7436 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
7437 @file{share/my-app/file}.
7442 @cindex Clojure (programming language)
7443 @cindex simple Clojure build system
7444 @defvr {Scheme Variable} clojure-build-system
7445 This variable is exported by @code{(guix build-system clojure)}. It implements
7446 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
7447 using plain old @code{compile} in Clojure. Cross-compilation is not supported
7450 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
7451 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
7452 @code{#:zip} parameters, respectively.
7454 A list of source directories, test directories and jar names can be specified
7455 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
7456 parameters, respectively. Compile directory and main class can be specified
7457 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
7458 Other parameters are documented below.
7460 This build system is an extension of @code{ant-build-system}, but with the
7461 following phases changed:
7466 This phase calls @code{compile} in Clojure to compile source files and runs
7467 @command{jar} to create jars from both source files and compiled files
7468 according to the include list and exclude list specified in
7469 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
7470 has priority over the include list. These lists consist of symbols
7471 representing Clojure libraries or the special keyword @code{#:all} representing
7472 all Clojure libraries found under the source directories. The parameter
7473 @code{#:omit-source?} decides if source should be included into the jars.
7476 This phase runs tests according to the include list and exclude list specified
7477 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
7478 meanings are analogous to that of @code{#:aot-include} and
7479 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
7480 stands for all Clojure libraries found under the test directories. The
7481 parameter @code{#:tests?} decides if tests should be run.
7484 This phase installs all jars built previously.
7487 Apart from the above, this build system also contains an additional phase:
7492 This phase installs all top-level files with base name matching
7493 @code{%doc-regex}. A different regex can be specified with the
7494 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
7495 directories specified in @code{#:doc-dirs} are installed as well.
7499 @defvr {Scheme Variable} cmake-build-system
7500 This variable is exported by @code{(guix build-system cmake)}. It
7501 implements the build procedure for packages using the
7502 @url{https://www.cmake.org, CMake build tool}.
7504 It automatically adds the @code{cmake} package to the set of inputs.
7505 Which package is used can be specified with the @code{#:cmake}
7508 The @code{#:configure-flags} parameter is taken as a list of flags
7509 passed to the @command{cmake} command. The @code{#:build-type}
7510 parameter specifies in abstract terms the flags passed to the compiler;
7511 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
7512 debugging information''), which roughly means that code is compiled with
7513 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
7516 @defvr {Scheme Variable} dune-build-system
7517 This variable is exported by @code{(guix build-system dune)}. It
7518 supports builds of packages using @uref{https://dune.build/, Dune}, a build
7519 tool for the OCaml programming language. It is implemented as an extension
7520 of the @code{ocaml-build-system} which is described below. As such, the
7521 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
7524 It automatically adds the @code{dune} package to the set of inputs.
7525 Which package is used can be specified with the @code{#:dune}
7528 There is no @code{configure} phase because dune packages typically don't
7529 need to be configured. The @code{#:build-flags} parameter is taken as a
7530 list of flags passed to the @code{dune} command during the build.
7532 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
7533 command instead of the more recent @code{dune} command while building
7534 a package. Its default value is @code{#f}.
7536 The @code{#:package} parameter can be passed to specify a package name, which
7537 is useful when a package contains multiple packages and you want to build
7538 only one of them. This is equivalent to passing the @code{-p} argument to
7542 @defvr {Scheme Variable} go-build-system
7543 This variable is exported by @code{(guix build-system go)}. It
7544 implements a build procedure for Go packages using the standard
7545 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
7546 Go build mechanisms}.
7548 The user is expected to provide a value for the key @code{#:import-path}
7549 and, in some cases, @code{#:unpack-path}. The
7550 @url{https://golang.org/doc/code.html#ImportPaths, import path}
7551 corresponds to the file system path expected by the package's build
7552 scripts and any referring packages, and provides a unique way to
7553 refer to a Go package. It is typically based on a combination of the
7554 package source code's remote URI and file system hierarchy structure. In
7555 some cases, you will need to unpack the package's source code to a
7556 different directory structure than the one indicated by the import path,
7557 and @code{#:unpack-path} should be used in such cases.
7559 Packages that provide Go libraries should install their source code into
7560 the built output. The key @code{#:install-source?}, which defaults to
7561 @code{#t}, controls whether or not the source code is installed. It can
7562 be set to @code{#f} for packages that only provide executable files.
7565 @defvr {Scheme Variable} glib-or-gtk-build-system
7566 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
7567 is intended for use with packages making use of GLib or GTK+.
7569 This build system adds the following two phases to the ones defined by
7570 @code{gnu-build-system}:
7573 @item glib-or-gtk-wrap
7574 The phase @code{glib-or-gtk-wrap} ensures that programs in
7575 @file{bin/} are able to find GLib ``schemas'' and
7576 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
7577 modules}. This is achieved by wrapping the programs in launch scripts
7578 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
7579 environment variables.
7581 It is possible to exclude specific package outputs from that wrapping
7582 process by listing their names in the
7583 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7584 when an output is known not to contain any GLib or GTK+ binaries, and
7585 where wrapping would gratuitously add a dependency of that output on
7588 @item glib-or-gtk-compile-schemas
7589 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7590 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7591 GSettings schemas} of GLib are compiled. Compilation is performed by the
7592 @command{glib-compile-schemas} program. It is provided by the package
7593 @code{glib:bin} which is automatically imported by the build system.
7594 The @code{glib} package providing @command{glib-compile-schemas} can be
7595 specified with the @code{#:glib} parameter.
7598 Both phases are executed after the @code{install} phase.
7601 @defvr {Scheme Variable} guile-build-system
7602 This build system is for Guile packages that consist exclusively of Scheme
7603 code and that are so lean that they don't even have a makefile, let alone a
7604 @file{configure} script. It compiles Scheme code using @command{guild
7605 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7606 installs the @file{.scm} and @file{.go} files in the right place. It also
7607 installs documentation.
7609 This build system supports cross-compilation by using the
7610 @option{--target} option of @samp{guild compile}.
7612 Packages built with @code{guile-build-system} must provide a Guile package in
7613 their @code{native-inputs} field.
7616 @defvr {Scheme Variable} julia-build-system
7617 This variable is exported by @code{(guix build-system julia)}. It
7618 implements the build procedure used by @uref{https://julialang.org/,
7619 julia} packages, which essentially is similar to running @samp{julia -e
7620 'using Pkg; Pkg.add(package)'} in an environment where
7621 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7622 Tests are run with @code{Pkg.test}.
7624 Julia packages require the source @code{file-name} to be the real name of the
7625 package, correctly capitalized.
7627 For packages requiring shared library dependencies, you may need to write the
7628 @file{/deps/deps.jl} file manually. It's usually a line of @code{const
7629 variable = /gnu/store/library.so} for each dependency, plus a void function
7630 @code{check_deps() = nothing}.
7632 Some older packages that aren't using @file{Package.toml} yet, will require
7633 this file to be created, too. The function @code{julia-create-package-toml}
7634 helps creating the file. You need to pass the outputs and the source of the
7635 package, it's name (the same as the @code{file-name} parameter), the package
7636 uuid, the package version, and a list of dependencies specified by their name
7640 @defvr {Scheme Variable} maven-build-system
7641 This variable is exported by @code{(guix build-system maven)}. It implements
7642 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7643 is a dependency and lifecycle management tool for Java. A user of Maven
7644 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7645 When Maven does not have one of the dependencies or plugins in its repository,
7646 it will download them and use them to build the package.
7648 The maven build system ensures that maven will not try to download any
7649 dependency by running in offline mode. Maven will fail if a dependency is
7650 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7651 modified to specify the version of dependencies and plugins that match the
7652 versions available in the guix build environment. Dependencies and plugins
7653 must be installed in the fake maven repository at @file{lib/m2}, and are
7654 symlinked into a proper repository before maven is run. Maven is instructed
7655 to use that repository for the build and installs built artifacts there.
7656 Changed files are copied to the @file{lib/m2} directory of the package output.
7658 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7659 or let the build system use the default @file{pom.xml} file in the sources.
7661 In case you need to specify a dependency's version manually, you can use the
7662 @code{#:local-packages} argument. It takes an association list where the key
7663 is the groupId of the package and its value is an association list where the
7664 key is the artifactId of the package and its value is the version you want to
7665 override in the @file{pom.xml}.
7667 Some packages use dependencies or plugins that are not useful at runtime nor
7668 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7669 using the @code{#:exclude} argument. Its value is an association list where
7670 the key is the groupId of the plugin or dependency you want to remove, and
7671 the value is a list of artifactId you want to remove.
7673 You can override the default @code{jdk} and @code{maven} packages with the
7674 corresponding argument, @code{#:jdk} and @code{#:maven}.
7676 The @code{#:maven-plugins} argument is a list of maven plugins used during
7677 the build, with the same format as the @code{inputs} fields of the package
7678 declaration. Its default value is @code{(default-maven-plugins)} which is
7682 @defvr {Scheme Variable} minify-build-system
7683 This variable is exported by @code{(guix build-system minify)}. It
7684 implements a minification procedure for simple JavaScript packages.
7686 It adds @code{uglify-js} to the set of inputs and uses it to compress
7687 all JavaScript files in the @file{src} directory. A different minifier
7688 package can be specified with the @code{#:uglify-js} parameter, but it
7689 is expected that the package writes the minified code to the standard
7692 When the input JavaScript files are not all located in the @file{src}
7693 directory, the parameter @code{#:javascript-files} can be used to
7694 specify a list of file names to feed to the minifier.
7697 @defvr {Scheme Variable} ocaml-build-system
7698 This variable is exported by @code{(guix build-system ocaml)}. It implements
7699 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7700 of choosing the correct set of commands to run for each package. OCaml
7701 packages can expect many different commands to be run. This build system will
7704 When the package has a @file{setup.ml} file present at the top-level, it will
7705 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7706 @code{ocaml setup.ml -install}. The build system will assume that this file
7707 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7708 care of setting the prefix and enabling tests if they are not disabled. You
7709 can pass configure and build flags with the @code{#:configure-flags} and
7710 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7711 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7712 bypass this system in the build and install phases.
7714 When the package has a @file{configure} file, it is assumed that it is a
7715 hand-made configure script that requires a different argument format than
7716 in the @code{gnu-build-system}. You can add more flags with the
7717 @code{#:configure-flags} key.
7719 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7720 @code{#t}), it will be used and more flags can be passed to the build and
7721 install phases with the @code{#:make-flags} key.
7723 Finally, some packages do not have these files and use a somewhat standard
7724 location for its build system. In that case, the build system will run
7725 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7726 providing the path to the required findlib module. Additional flags can
7727 be passed via the @code{#:build-flags} key. Install is taken care of by
7728 @command{opam-installer}. In this case, the @code{opam} package must
7729 be added to the @code{native-inputs} field of the package definition.
7731 Note that most OCaml packages assume they will be installed in the same
7732 directory as OCaml, which is not what we want in guix. In particular, they
7733 will install @file{.so} files in their module's directory, which is usually
7734 fine because it is in the OCaml compiler directory. In guix though, these
7735 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7736 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7737 @file{.so} libraries should be installed.
7740 @defvr {Scheme Variable} python-build-system
7741 This variable is exported by @code{(guix build-system python)}. It
7742 implements the more or less standard build procedure used by Python
7743 packages, which consists in running @code{python setup.py build} and
7744 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7746 For packages that install stand-alone Python programs under @code{bin/},
7747 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7748 environment variable points to all the Python libraries they depend on.
7750 Which Python package is used to perform the build can be specified with
7751 the @code{#:python} parameter. This is a useful way to force a package
7752 to be built for a specific version of the Python interpreter, which
7753 might be necessary if the package is only compatible with a single
7754 interpreter version.
7756 By default guix calls @code{setup.py} under control of
7757 @code{setuptools}, much like @command{pip} does. Some packages are not
7758 compatible with setuptools (and pip), thus you can disable this by
7759 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7762 @defvr {Scheme Variable} perl-build-system
7763 This variable is exported by @code{(guix build-system perl)}. It
7764 implements the standard build procedure for Perl packages, which either
7765 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7766 followed by @code{Build} and @code{Build install}; or in running
7767 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7768 @code{make} and @code{make install}, depending on which of
7769 @code{Build.PL} or @code{Makefile.PL} is present in the package
7770 distribution. Preference is given to the former if both @code{Build.PL}
7771 and @code{Makefile.PL} exist in the package distribution. This
7772 preference can be reversed by specifying @code{#t} for the
7773 @code{#:make-maker?} parameter.
7775 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7776 passes flags specified by the @code{#:make-maker-flags} or
7777 @code{#:module-build-flags} parameter, respectively.
7779 Which Perl package is used can be specified with @code{#:perl}.
7782 @defvr {Scheme Variable} qt-build-system
7783 This variable is exported by @code{(guix build-system qt)}. It
7784 is intended for use with applications using Qt or KDE.
7786 This build system adds the following two phases to the ones defined by
7787 @code{cmake-build-system}:
7791 The phase @code{check-setup} prepares the environment for running
7792 the checks as commonly used by Qt test programs.
7793 For now this only sets some environment variables:
7794 @code{QT_QPA_PLATFORM=offscreen},
7795 @code{DBUS_FATAL_WARNINGS=0} and
7796 @code{CTEST_OUTPUT_ON_FAILURE=1}.
7798 This phase is added before the @code{check} phase.
7799 It's a separate phase to ease adjusting if necessary.
7802 The phase @code{qt-wrap}
7803 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
7804 and output. In case some path is found, all programs in the output's
7805 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
7806 are wrapped in scripts defining the necessary environment variables.
7808 It is possible to exclude specific package outputs from that wrapping process
7809 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
7810 This is useful when an output is known not to contain any Qt binaries, and
7811 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
7814 This phase is added after the @code{install} phase.
7818 @defvr {Scheme Variable} r-build-system
7819 This variable is exported by @code{(guix build-system r)}. It
7820 implements the build procedure used by @uref{https://r-project.org, R}
7821 packages, which essentially is little more than running @samp{R CMD
7822 INSTALL --library=/gnu/store/@dots{}} in an environment where
7823 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
7824 run after installation using the R function
7825 @code{tools::testInstalledPackage}.
7828 @defvr {Scheme Variable} rakudo-build-system
7829 This variable is exported by @code{(guix build-system rakudo)}. It
7830 implements the build procedure used by @uref{https://rakudo.org/,
7831 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
7832 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
7833 installs the binaries, library files and the resources, as well as wrap
7834 the files under the @code{bin/} directory. Tests can be skipped by
7835 passing @code{#f} to the @code{tests?} parameter.
7837 Which rakudo package is used can be specified with @code{rakudo}.
7838 Which perl6-tap-harness package used for the tests can be specified with
7839 @code{#:prove6} or removed by passing @code{#f} to the
7840 @code{with-prove6?} parameter.
7841 Which perl6-zef package used for tests and installing can be specified
7842 with @code{#:zef} or removed by passing @code{#f} to the
7843 @code{with-zef?} parameter.
7846 @defvr {Scheme Variable} texlive-build-system
7847 This variable is exported by @code{(guix build-system texlive)}. It is
7848 used to build TeX packages in batch mode with a specified engine. The
7849 build system sets the @env{TEXINPUTS} variable to find all TeX source
7850 files in the inputs.
7852 By default it runs @code{luatex} on all files ending on @code{ins}. A
7853 different engine and format can be specified with the
7854 @code{#:tex-format} argument. Different build targets can be specified
7855 with the @code{#:build-targets} argument, which expects a list of file
7856 names. The build system adds only @code{texlive-bin} and
7857 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
7858 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
7859 and @code{#:texlive-latex-base}, respectively.
7861 The @code{#:tex-directory} parameter tells the build system where to
7862 install the built files under the texmf tree.
7865 @defvr {Scheme Variable} ruby-build-system
7866 This variable is exported by @code{(guix build-system ruby)}. It
7867 implements the RubyGems build procedure used by Ruby packages, which
7868 involves running @code{gem build} followed by @code{gem install}.
7870 The @code{source} field of a package that uses this build system
7871 typically references a gem archive, since this is the format that Ruby
7872 developers use when releasing their software. The build system unpacks
7873 the gem archive, potentially patches the source, runs the test suite,
7874 repackages the gem, and installs it. Additionally, directories and
7875 tarballs may be referenced to allow building unreleased gems from Git or
7876 a traditional source release tarball.
7878 Which Ruby package is used can be specified with the @code{#:ruby}
7879 parameter. A list of additional flags to be passed to the @command{gem}
7880 command can be specified with the @code{#:gem-flags} parameter.
7883 @defvr {Scheme Variable} waf-build-system
7884 This variable is exported by @code{(guix build-system waf)}. It
7885 implements a build procedure around the @code{waf} script. The common
7886 phases---@code{configure}, @code{build}, and @code{install}---are
7887 implemented by passing their names as arguments to the @code{waf}
7890 The @code{waf} script is executed by the Python interpreter. Which
7891 Python package is used to run the script can be specified with the
7892 @code{#:python} parameter.
7895 @defvr {Scheme Variable} scons-build-system
7896 This variable is exported by @code{(guix build-system scons)}. It
7897 implements the build procedure used by the SCons software construction
7898 tool. This build system runs @code{scons} to build the package,
7899 @code{scons test} to run tests, and then @code{scons install} to install
7902 Additional flags to be passed to @code{scons} can be specified with the
7903 @code{#:scons-flags} parameter. The default build and install targets
7904 can be overridden with @code{#:build-targets} and
7905 @code{#:install-targets} respectively. The version of Python used to
7906 run SCons can be specified by selecting the appropriate SCons package
7907 with the @code{#:scons} parameter.
7910 @defvr {Scheme Variable} haskell-build-system
7911 This variable is exported by @code{(guix build-system haskell)}. It
7912 implements the Cabal build procedure used by Haskell packages, which
7913 involves running @code{runhaskell Setup.hs configure
7914 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
7915 Instead of installing the package by running @code{runhaskell Setup.hs
7916 install}, to avoid trying to register libraries in the read-only
7917 compiler store directory, the build system uses @code{runhaskell
7918 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
7919 addition, the build system generates the package documentation by
7920 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
7921 is passed. Optional Haddock parameters can be passed with the help of
7922 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
7923 not found, the build system looks for @code{Setup.lhs} instead.
7925 Which Haskell compiler is used can be specified with the @code{#:haskell}
7926 parameter which defaults to @code{ghc}.
7929 @defvr {Scheme Variable} dub-build-system
7930 This variable is exported by @code{(guix build-system dub)}. It
7931 implements the Dub build procedure used by D packages, which
7932 involves running @code{dub build} and @code{dub run}.
7933 Installation is done by copying the files manually.
7935 Which D compiler is used can be specified with the @code{#:ldc}
7936 parameter which defaults to @code{ldc}.
7939 @anchor{emacs-build-system}
7940 @defvr {Scheme Variable} emacs-build-system
7941 This variable is exported by @code{(guix build-system emacs)}. It
7942 implements an installation procedure similar to the packaging system
7943 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
7945 It first creates the @code{@code{package}-autoloads.el} file, then it
7946 byte compiles all Emacs Lisp files. Differently from the Emacs
7947 packaging system, the Info documentation files are moved to the standard
7948 documentation directory and the @file{dir} file is deleted. The Elisp
7949 package files are installed directly under @file{share/emacs/site-lisp}.
7952 @defvr {Scheme Variable} font-build-system
7953 This variable is exported by @code{(guix build-system font)}. It
7954 implements an installation procedure for font packages where upstream
7955 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
7956 need to be copied into place. It copies font files to standard
7957 locations in the output directory.
7960 @defvr {Scheme Variable} meson-build-system
7961 This variable is exported by @code{(guix build-system meson)}. It
7962 implements the build procedure for packages that use
7963 @url{https://mesonbuild.com, Meson} as their build system.
7965 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
7966 of inputs, and they can be changed with the parameters @code{#:meson}
7967 and @code{#:ninja} if needed. The default Meson is
7968 @code{meson-for-build}, which is special because it doesn't clear the
7969 @code{RUNPATH} of binaries and libraries when they are installed.
7971 This build system is an extension of @code{gnu-build-system}, but with the
7972 following phases changed to some specific for Meson:
7977 The phase runs @code{meson} with the flags specified in
7978 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
7979 @code{debugoptimized} unless something else is specified in
7980 @code{#:build-type}.
7983 The phase runs @code{ninja} to build the package in parallel by default, but
7984 this can be changed with @code{#:parallel-build?}.
7987 The phase runs @code{ninja} with the target specified in @code{#:test-target},
7988 which is @code{"test"} by default.
7991 The phase runs @code{ninja install} and can not be changed.
7994 Apart from that, the build system also adds the following phases:
7999 This phase ensures that all binaries can find the libraries they need.
8000 It searches for required libraries in subdirectories of the package being
8001 built, and adds those to @code{RUNPATH} where needed. It also removes
8002 references to libraries left over from the build phase by
8003 @code{meson-for-build}, such as test dependencies, that aren't actually
8004 required for the program to run.
8006 @item glib-or-gtk-wrap
8007 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8008 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8010 @item glib-or-gtk-compile-schemas
8011 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8012 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8016 @defvr {Scheme Variable} linux-module-build-system
8017 @code{linux-module-build-system} allows building Linux kernel modules.
8019 @cindex build phases
8020 This build system is an extension of @code{gnu-build-system}, but with the
8021 following phases changed:
8026 This phase configures the environment so that the Linux kernel's Makefile
8027 can be used to build the external kernel module.
8030 This phase uses the Linux kernel's Makefile in order to build the external
8034 This phase uses the Linux kernel's Makefile in order to install the external
8038 It is possible and useful to specify the Linux kernel to use for building
8039 the module (in the @code{arguments} form of a package using the
8040 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
8043 @defvr {Scheme Variable} node-build-system
8044 This variable is exported by @code{(guix build-system node)}. It
8045 implements the build procedure used by @uref{https://nodejs.org,
8046 Node.js}, which implements an approximation of the @code{npm install}
8047 command, followed by an @code{npm test} command.
8049 Which Node.js package is used to interpret the @code{npm} commands can
8050 be specified with the @code{#:node} parameter which defaults to
8054 Lastly, for packages that do not need anything as sophisticated, a
8055 ``trivial'' build system is provided. It is trivial in the sense that
8056 it provides basically no support: it does not pull any implicit inputs,
8057 and does not have a notion of build phases.
8059 @defvr {Scheme Variable} trivial-build-system
8060 This variable is exported by @code{(guix build-system trivial)}.
8062 This build system requires a @code{#:builder} argument. This argument
8063 must be a Scheme expression that builds the package output(s)---as
8064 with @code{build-expression->derivation} (@pxref{Derivations,
8065 @code{build-expression->derivation}}).
8069 @section Build Phases
8071 @cindex build phases, for packages
8072 Almost all package build systems implement a notion @dfn{build phases}:
8073 a sequence of actions that the build system executes, when you build the
8074 package, leading to the installed byproducts in the store. A notable
8075 exception is the ``bare-bones'' @code{trivial-build-system}
8076 (@pxref{Build Systems}).
8078 As discussed in the previous section, those build systems provide a
8079 standard list of phases. For @code{gnu-build-system}, the standard
8080 phases include an @code{unpack} phase to unpack the source code tarball,
8081 a @command{configure} phase to run @code{./configure}, a @code{build}
8082 phase to run @command{make}, and (among others) an @code{install} phase
8083 to run @command{make install}; @pxref{Build Systems}, for a more
8084 detailed view of these phases. Likewise, @code{cmake-build-system}
8085 inherits these phases, but its @code{configure} phase runs
8086 @command{cmake} instead of @command{./configure}. Other build systems,
8087 such as @code{python-build-system}, have a wholly different list of
8088 standard phases. All this code runs on the @dfn{build side}: it is
8089 evaluated when you actually build the package, in a dedicated build
8090 process spawned by the build daemon (@pxref{Invoking guix-daemon}).
8092 Build phases are represented as association lists or ``alists''
8093 (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
8094 each key is a symbol for the name of the phase and the associated value
8095 is a procedure that accepts an arbitrary number of arguments. By
8096 convention, those procedures receive information about the build in the
8097 form of @dfn{keyword parameters}, which they can use or ignore.
8099 For example, here is how @code{(guix build gnu-build-system)} defines
8100 @code{%standard-phases}, the variable holding its alist of build
8101 phases@footnote{We present a simplified view of those build phases, but
8102 do take a look at @code{(guix build gnu-build-system)} to see all the
8106 ;; The build phases of 'gnu-build-system'.
8108 (define* (unpack #:key source #:allow-other-keys)
8109 ;; Extract the source tarball.
8110 (invoke "tar" "xvf" source))
8112 (define* (configure #:key outputs #:allow-other-keys)
8113 ;; Run the 'configure' script. Install to output "out".
8114 (let ((out (assoc-ref outputs "out")))
8115 (invoke "./configure"
8116 (string-append "--prefix=" out))))
8118 (define* (build #:allow-other-keys)
8122 (define* (check #:key (test-target "check") (tests? #true)
8124 ;; Run the test suite.
8126 (invoke "make" test-target)
8127 (display "test suite not run\n")))
8129 (define* (install #:allow-other-keys)
8130 ;; Install files to the prefix 'configure' specified.
8131 (invoke "make" "install"))
8133 (define %standard-phases
8134 ;; The list of standard phases (quite a few are omitted
8135 ;; for brevity). Each element is a symbol/procedure pair.
8136 (list (cons 'unpack unpack)
8137 (cons 'configure configure)
8140 (cons 'install install)))
8143 This shows how @code{%standard-phases} is defined as a list of
8144 symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
8145 Manual}). The first pair associates the @code{unpack} procedure with
8146 the @code{unpack} symbol---a name; the second pair defines the
8147 @code{configure} phase similarly, and so on. When building a package
8148 that uses @code{gnu-build-system} with its default list of phases, those
8149 phases are executed sequentially. You can see the name of each phase
8150 started and completed in the build log of packages that you build.
8152 Let's now look at the procedures themselves. Each one is defined with
8153 @code{define*}: @code{#:key} lists keyword parameters the procedure
8154 accepts, possibly with a default value, and @code{#:allow-other-keys}
8155 specifies that other keyword parameters are ignored (@pxref{Optional
8156 Arguments,,, guile, GNU Guile Reference Manual}).
8158 The @code{unpack} procedure honors the @code{source} parameter, which
8159 the build system uses to pass the file name of the source tarball (or
8160 version control checkout), and it ignores other parameters. The
8161 @code{configure} phase only cares about the @code{outputs} parameter, an
8162 alist mapping package output names to their store file name
8163 (@pxref{Packages with Multiple Outputs}). It extracts the file name of
8164 for @code{out}, the default output, and passes it to
8165 @command{./configure} as the installation prefix, meaning that
8166 @command{make install} will eventually copy all the files in that
8167 directory (@pxref{Configuration, configuration and makefile
8168 conventions,, standards, GNU Coding Standards}). @code{build} and
8169 @code{install} ignore all their arguments. @code{check} honors the
8170 @code{test-target} argument, which specifies the name of the Makefile
8171 target to run tests; it prints a message and skips tests when
8172 @code{tests?} is false.
8174 @cindex build phases, customizing
8175 The list of phases used for a particular package can be changed with the
8176 @code{#:phases} parameter of the build system. Changing the set of
8177 build phases boils down to building a new alist of phases based on the
8178 @code{%standard-phases} alist described above. This can be done with
8179 standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
8180 Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
8181 more convenient to do so with @code{modify-phases} (@pxref{Build
8182 Utilities, @code{modify-phases}}).
8184 Here is an example of a package definition that removes the
8185 @code{configure} phase of @code{%standard-phases} and inserts a new
8186 phase before the @code{build} phase, called
8187 @code{set-prefix-in-makefile}:
8190 (define-public example
8193 ;; other fields omitted
8194 (build-system gnu-build-system)
8196 '(#:phases (modify-phases %standard-phases
8198 (add-before 'build 'set-prefix-in-makefile
8199 (lambda* (#:key outputs #:allow-other-keys)
8200 ;; Modify the makefile so that its
8201 ;; 'PREFIX' variable points to "out".
8202 (let ((out (assoc-ref outputs "out")))
8203 (substitute* "Makefile"
8205 (string-append "PREFIX = "
8210 The new phase that is inserted is written as an anonymous procedure,
8211 introduced with @code{lambda*}; it honors the @code{outputs} parameter
8212 we have seen before. @xref{Build Utilities}, for more about the helpers
8213 used by this phase, and for more examples of @code{modify-phases}.
8215 @cindex code staging
8216 @cindex staging, of code
8217 Keep in mind that build phases are code evaluated at the time the
8218 package is actually built. This explains why the whole
8219 @code{modify-phases} expression above is quoted (it comes after the
8220 @code{'} or apostrophe): it is @dfn{staged} for later execution.
8221 @xref{G-Expressions}, for an explanation of code staging and the
8222 @dfn{code strata} involved.
8224 @node Build Utilities
8225 @section Build Utilities
8227 As soon as you start writing non-trivial package definitions
8228 (@pxref{Defining Packages}) or other build actions
8229 (@pxref{G-Expressions}), you will likely start looking for helpers for
8230 ``shell-like'' actions---creating directories, copying and deleting
8231 files recursively, manipulating build phases, and so on. The
8232 @code{(guix build utils)} module provides such utility procedures.
8234 Most build systems load @code{(guix build utils)} (@pxref{Build
8235 Systems}). Thus, when writing custom build phases for your package
8236 definitions, you can usually assume those procedures are in scope.
8238 When writing G-expressions, you can import @code{(guix build utils)} on
8239 the ``build side'' using @code{with-imported-modules} and then put it in
8240 scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
8241 guile, GNU Guile Reference Manual}):
8244 (with-imported-modules '((guix build utils)) ;import it
8245 (computed-file "empty-tree"
8248 (use-modules (guix build utils))
8250 ;; Happily use its 'mkdir-p' procedure.
8251 (mkdir-p (string-append #$output "/a/b/c")))))
8254 The remainder of this section is the reference for most of the utility
8255 procedures provided by @code{(guix build utils)}.
8257 @c TODO Document what's missing.
8259 @subsection Dealing with Store File Names
8261 This section documents procedures that deal with store file names.
8263 @deffn {Scheme Procedure} %store-directory
8264 Return the directory name of the store.
8267 @deffn {Scheme Procedure} store-file-name? @var{file}
8268 Return true if @var{file} is in the store.
8271 @deffn {Scheme Procedure} strip-store-file-name @var{file}
8272 Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
8273 The result is typically a @code{"@var{package}-@var{version}"} string.
8276 @deffn {Scheme Procedure} package-name->name+version @var{name}
8277 Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
8278 values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
8279 unavailable, @var{name} and @code{#f} are returned. The first hyphen
8280 followed by a digit is considered to introduce the version part.
8283 @subsection File Types
8285 The procedures below deal with files and file types.
8287 @deffn {Scheme Procedure} directory-exists? @var{dir}
8288 Return @code{#t} if @var{dir} exists and is a directory.
8291 @deffn {Scheme Procedure} executable-file? @var{file}
8292 Return @code{#t} if @var{file} exists and is executable.
8295 @deffn {Scheme Procedure} symbolic-link? @var{file}
8296 Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
8299 @deffn {Scheme Procedure} elf-file? @var{file}
8300 @deffnx {Scheme Procedure} ar-file? @var{file}
8301 @deffnx {Scheme Procedure} gzip-file? @var{file}
8302 Return @code{#t} if @var{file} is, respectively, an ELF file, an
8303 @code{ar} archive (such as a @file{.a} static library), or a gzip file.
8306 @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
8307 If @var{file} is a gzip file, reset its embedded timestamp (as with
8308 @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
8309 When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
8312 @subsection File Manipulation
8314 The following procedures and macros help create, modify, and delete
8315 files. They provide functionality comparable to common shell utilities
8316 such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
8317 @command{sed}. They complement Guile's extensive, but low-level, file
8318 system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
8320 @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
8321 Run @var{body} with @var{directory} as the process's current directory.
8323 Essentially, this macro changes the current directory to @var{directory}
8324 before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
8325 guile, GNU Guile Reference Manual}). It changes back to the initial
8326 directory when the dynamic extent of @var{body} is left, be it @i{via}
8327 normal procedure return or @i{via} a non-local exit such as an
8331 @deffn {Scheme Procedure} mkdir-p @var{dir}
8332 Create directory @var{dir} and all its ancestors.
8335 @deffn {Scheme Procedure} install-file @var{file} @var{directory}
8336 Create @var{directory} if it does not exist and copy @var{file} in there
8337 under the same name.
8340 @deffn {Scheme Procedure} make-file-writable @var{file}
8341 Make @var{file} writable for its owner.
8344 @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
8345 [#:log (current-output-port)] [#:follow-symlinks? #f] [#:keep-mtime? #f]
8346 Copy @var{source} directory to @var{destination}. Follow symlinks if
8347 @var{follow-symlinks?} is true; otherwise, just preserve them. When
8348 @var{keep-mtime?} is true, keep the modification time of the files in
8349 @var{source} on those of @var{destination}. Write verbose output to the
8353 @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
8354 [#:follow-mounts? #f]
8355 Delete @var{dir} recursively, like @command{rm -rf}, without following
8356 symlinks. Don't follow mount points either, unless @var{follow-mounts?}
8357 is true. Report but ignore errors.
8360 @deffn {Scheme Syntax} substitute* @var{file} @
8361 ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
8362 Substitute @var{regexp} in @var{file} by the string returned by
8363 @var{body}. @var{body} is evaluated with each @var{match-var} bound to
8364 the corresponding positional regexp sub-expression. For example:
8370 (("foo([a-z]+)bar(.*)$" all letters end)
8371 (string-append "baz" letter end)))
8374 Here, anytime a line of @var{file} contains @code{hello}, it is replaced
8375 by @code{good morning}. Anytime a line of @var{file} matches the second
8376 regexp, @code{all} is bound to the complete match, @code{letters} is bound
8377 to the first sub-expression, and @code{end} is bound to the last one.
8379 When one of the @var{match-var} is @code{_}, no variable is bound to the
8380 corresponding match substring.
8382 Alternatively, @var{file} may be a list of file names, in which case
8383 they are all subject to the substitutions.
8385 Be careful about using @code{$} to match the end of a line; by itself it
8386 won't match the terminating newline of a line.
8389 @subsection File Search
8391 @cindex file, searching
8392 This section documents procedures to search and filter files.
8394 @deffn {Scheme Procedure} file-name-predicate @var{regexp}
8395 Return a predicate that returns true when passed a file name whose base
8396 name matches @var{regexp}.
8399 @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
8400 [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
8401 Return the lexicographically sorted list of files under @var{dir} for
8402 which @var{pred} returns true. @var{pred} is passed two arguments: the
8403 absolute file name, and its stat buffer; the default predicate always
8404 returns true. @var{pred} can also be a regular expression, in which
8405 case it is equivalent to @code{(file-name-predicate @var{pred})}.
8406 @var{stat} is used to obtain file information; using @code{lstat} means
8407 that symlinks are not followed. If @var{directories?} is true, then
8408 directories will also be included. If @var{fail-on-error?} is true,
8409 raise an exception upon error.
8412 Here are a few examples where we assume that the current directory is
8413 the root of the Guix source tree:
8416 ;; List all the regular files in the current directory.
8418 @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
8420 ;; List all the .scm files under gnu/services.
8421 (find-files "gnu/services" "\\.scm$")
8422 @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
8424 ;; List ar files in the current directory.
8425 (find-files "." (lambda (file stat) (ar-file? file)))
8426 @result{} ("./libformat.a" "./libstore.a" @dots{})
8429 @deffn {Scheme Procedure} which @var{program}
8430 Return the complete file name for @var{program} as found in
8431 @code{$PATH}, or @code{#f} if @var{program} could not be found.
8434 @subsection Build Phases
8436 @cindex build phases
8437 The @code{(guix build utils)} also contains tools to manipulate build
8438 phases as used by build systems (@pxref{Build Systems}). Build phases
8439 are represented as association lists or ``alists'' (@pxref{Association
8440 Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
8441 naming the phase and the associated value is a procedure (@pxref{Build
8444 Guile core and the @code{(srfi srfi-1)} module both provide tools to
8445 manipulate alists. The @code{(guix build utils)} module complements
8446 those with tools written with build phases in mind.
8448 @cindex build phases, modifying
8449 @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
8450 Modify @var{phases} sequentially as per each @var{clause}, which may
8451 have one of the following forms:
8454 (delete @var{old-phase-name})
8455 (replace @var{old-phase-name} @var{new-phase})
8456 (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8457 (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8460 Where every @var{phase-name} above is an expression evaluating to a
8461 symbol, and @var{new-phase} an expression evaluating to a procedure.
8464 The example below is taken from the definition of the @code{grep}
8465 package. It adds a phase to run after the @code{install} phase, called
8466 @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
8467 is for anonymous procedures) that takes a @code{#:outputs} keyword
8468 argument and ignores extra keyword arguments (@pxref{Optional
8469 Arguments,,, guile, GNU Guile Reference Manual}, for more on
8470 @code{lambda*} and optional and keyword arguments.) The phase uses
8471 @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
8472 scripts so that they refer to @code{grep} by its absolute file name:
8475 (modify-phases %standard-phases
8476 (add-after 'install 'fix-egrep-and-fgrep
8477 ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
8478 ;; absolute file name instead of searching for it in $PATH.
8479 (lambda* (#:key outputs #:allow-other-keys)
8480 (let* ((out (assoc-ref outputs "out"))
8481 (bin (string-append out "/bin")))
8482 (substitute* (list (string-append bin "/egrep")
8483 (string-append bin "/fgrep"))
8485 (string-append "exec " bin "/grep")))
8489 In the example below, phases are modified in two ways: the standard
8490 @code{configure} phase is deleted, presumably because the package does
8491 not have a @file{configure} script or anything similar, and the default
8492 @code{install} phase is replaced by one that manually copies the
8493 executable files to be installed:
8496 (modify-phases %standard-phases
8497 (delete 'configure) ;no 'configure' script
8499 (lambda* (#:key outputs #:allow-other-keys)
8500 ;; The package's Makefile doesn't provide an "install"
8501 ;; rule so do it by ourselves.
8502 (let ((bin (string-append (assoc-ref outputs "out")
8504 (install-file "footswitch" bin)
8505 (install-file "scythe" bin)
8509 @c TODO: Add more examples.
8518 Conceptually, the @dfn{store} is the place where derivations that have
8519 been built successfully are stored---by default, @file{/gnu/store}.
8520 Sub-directories in the store are referred to as @dfn{store items} or
8521 sometimes @dfn{store paths}. The store has an associated database that
8522 contains information such as the store paths referred to by each store
8523 path, and the list of @emph{valid} store items---results of successful
8524 builds. This database resides in @file{@var{localstatedir}/guix/db},
8525 where @var{localstatedir} is the state directory specified @i{via}
8526 @option{--localstatedir} at configure time, usually @file{/var}.
8528 The store is @emph{always} accessed by the daemon on behalf of its clients
8529 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
8530 connect to the daemon over a Unix-domain socket, send requests to it,
8531 and read the result---these are remote procedure calls, or RPCs.
8534 Users must @emph{never} modify files under @file{/gnu/store} directly.
8535 This would lead to inconsistencies and break the immutability
8536 assumptions of Guix's functional model (@pxref{Introduction}).
8538 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
8539 how to check the integrity of the store and attempt recovery from
8540 accidental modifications.
8543 The @code{(guix store)} module provides procedures to connect to the
8544 daemon, and to perform RPCs. These are described below. By default,
8545 @code{open-connection}, and thus all the @command{guix} commands,
8546 connect to the local daemon or to the URI specified by the
8547 @env{GUIX_DAEMON_SOCKET} environment variable.
8549 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
8550 When set, the value of this variable should be a file name or a URI
8551 designating the daemon endpoint. When it is a file name, it denotes a
8552 Unix-domain socket to connect to. In addition to file names, the
8553 supported URI schemes are:
8558 These are for Unix-domain sockets.
8559 @code{file:///var/guix/daemon-socket/socket} is equivalent to
8560 @file{/var/guix/daemon-socket/socket}.
8563 @cindex daemon, remote access
8564 @cindex remote access to the daemon
8565 @cindex daemon, cluster setup
8566 @cindex clusters, daemon setup
8567 These URIs denote connections over TCP/IP, without encryption nor
8568 authentication of the remote host. The URI must specify the host name
8569 and optionally a port number (by default port 44146 is used):
8572 guix://master.guix.example.org:1234
8575 This setup is suitable on local networks, such as clusters, where only
8576 trusted nodes may connect to the build daemon at
8577 @code{master.guix.example.org}.
8579 The @option{--listen} option of @command{guix-daemon} can be used to
8580 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
8581 @option{--listen}}).
8584 @cindex SSH access to build daemons
8585 These URIs allow you to connect to a remote daemon over SSH. This
8586 feature requires Guile-SSH (@pxref{Requirements}) and a working
8587 @command{guile} binary in @env{PATH} on the destination machine. It
8588 supports public key and GSSAPI authentication. A typical URL might look
8592 ssh://charlie@@guix.example.org:22
8595 As for @command{guix copy}, the usual OpenSSH client configuration files
8596 are honored (@pxref{Invoking guix copy}).
8599 Additional URI schemes may be supported in the future.
8601 @c XXX: Remove this note when the protocol incurs fewer round trips
8602 @c and when (guix derivations) no longer relies on file system access.
8604 The ability to connect to remote build daemons is considered
8605 experimental as of @value{VERSION}. Please get in touch with us to
8606 share any problems or suggestions you may have (@pxref{Contributing}).
8610 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
8611 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
8612 @var{reserve-space?} is true, instruct it to reserve a little bit of
8613 extra space on the file system so that the garbage collector can still
8614 operate should the disk become full. Return a server object.
8616 @var{file} defaults to @code{%default-socket-path}, which is the normal
8617 location given the options that were passed to @command{configure}.
8620 @deffn {Scheme Procedure} close-connection @var{server}
8621 Close the connection to @var{server}.
8624 @defvr {Scheme Variable} current-build-output-port
8625 This variable is bound to a SRFI-39 parameter, which refers to the port
8626 where build and error logs sent by the daemon should be written.
8629 Procedures that make RPCs all take a server object as their first
8632 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
8633 @cindex invalid store items
8634 Return @code{#t} when @var{path} designates a valid store item and
8635 @code{#f} otherwise (an invalid item may exist on disk but still be
8636 invalid, for instance because it is the result of an aborted or failed
8639 A @code{&store-protocol-error} condition is raised if @var{path} is not
8640 prefixed by the store directory (@file{/gnu/store}).
8643 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
8644 Add @var{text} under file @var{name} in the store, and return its store
8645 path. @var{references} is the list of store paths referred to by the
8646 resulting store path.
8649 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
8651 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
8652 file names, or derivation/output pairs, using the specified
8653 @var{mode}---@code{(build-mode normal)} by default.
8656 Note that the @code{(guix monads)} module provides a monad as well as
8657 monadic versions of the above procedures, with the goal of making it
8658 more convenient to work with code that accesses the store (@pxref{The
8662 @i{This section is currently incomplete.}
8665 @section Derivations
8668 Low-level build actions and the environment in which they are performed
8669 are represented by @dfn{derivations}. A derivation contains the
8670 following pieces of information:
8674 The outputs of the derivation---derivations produce at least one file or
8675 directory in the store, but may produce more.
8678 @cindex build-time dependencies
8679 @cindex dependencies, build-time
8680 The inputs of the derivations---i.e., its build-time dependencies---which may
8681 be other derivations or plain files in the store (patches, build scripts,
8685 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
8688 The file name of a build script in the store, along with the arguments
8692 A list of environment variables to be defined.
8696 @cindex derivation path
8697 Derivations allow clients of the daemon to communicate build actions to
8698 the store. They exist in two forms: as an in-memory representation,
8699 both on the client- and daemon-side, and as files in the store whose
8700 name end in @file{.drv}---these files are referred to as @dfn{derivation
8701 paths}. Derivations paths can be passed to the @code{build-derivations}
8702 procedure to perform the build actions they prescribe (@pxref{The
8705 @cindex fixed-output derivations
8706 Operations such as file downloads and version-control checkouts for
8707 which the expected content hash is known in advance are modeled as
8708 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
8709 of a fixed-output derivation are independent of its inputs---e.g., a
8710 source code download produces the same result regardless of the download
8711 method and tools being used.
8714 @cindex run-time dependencies
8715 @cindex dependencies, run-time
8716 The outputs of derivations---i.e., the build results---have a set of
8717 @dfn{references}, as reported by the @code{references} RPC or the
8718 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
8719 are the set of run-time dependencies of the build results. References are a
8720 subset of the inputs of the derivation; this subset is automatically computed
8721 by the build daemon by scanning all the files in the outputs.
8723 The @code{(guix derivations)} module provides a representation of
8724 derivations as Scheme objects, along with procedures to create and
8725 otherwise manipulate derivations. The lowest-level primitive to create
8726 a derivation is the @code{derivation} procedure:
8728 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
8729 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8730 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
8731 [#:system (%current-system)] [#:references-graphs #f] @
8732 [#:allowed-references #f] [#:disallowed-references #f] @
8733 [#:leaked-env-vars #f] [#:local-build? #f] @
8734 [#:substitutable? #t] [#:properties '()]
8735 Build a derivation with the given arguments, and return the resulting
8736 @code{<derivation>} object.
8738 When @var{hash} and @var{hash-algo} are given, a
8739 @dfn{fixed-output derivation} is created---i.e., one whose result is
8740 known in advance, such as a file download. If, in addition,
8741 @var{recursive?} is true, then that fixed output may be an executable
8742 file or a directory and @var{hash} must be the hash of an archive
8743 containing this output.
8745 When @var{references-graphs} is true, it must be a list of file
8746 name/store path pairs. In that case, the reference graph of each store
8747 path is exported in the build environment in the corresponding file, in
8748 a simple text format.
8750 When @var{allowed-references} is true, it must be a list of store items
8751 or outputs that the derivation's output may refer to. Likewise,
8752 @var{disallowed-references}, if true, must be a list of things the
8753 outputs may @emph{not} refer to.
8755 When @var{leaked-env-vars} is true, it must be a list of strings
8756 denoting environment variables that are allowed to ``leak'' from the
8757 daemon's environment to the build environment. This is only applicable
8758 to fixed-output derivations---i.e., when @var{hash} is true. The main
8759 use is to allow variables such as @code{http_proxy} to be passed to
8760 derivations that download files.
8762 When @var{local-build?} is true, declare that the derivation is not a
8763 good candidate for offloading and should rather be built locally
8764 (@pxref{Daemon Offload Setup}). This is the case for small derivations
8765 where the costs of data transfers would outweigh the benefits.
8767 When @var{substitutable?} is false, declare that substitutes of the
8768 derivation's output should not be used (@pxref{Substitutes}). This is
8769 useful, for instance, when building packages that capture details of the
8770 host CPU instruction set.
8772 @var{properties} must be an association list describing ``properties'' of the
8773 derivation. It is kept as-is, uninterpreted, in the derivation.
8777 Here's an example with a shell script as its builder, assuming
8778 @var{store} is an open connection to the daemon, and @var{bash} points
8779 to a Bash executable in the store:
8782 (use-modules (guix utils)
8786 (let ((builder ; add the Bash script to the store
8787 (add-text-to-store store "my-builder.sh"
8788 "echo hello world > $out\n" '())))
8789 (derivation store "foo"
8790 bash `("-e" ,builder)
8791 #:inputs `((,bash) (,builder))
8792 #:env-vars '(("HOME" . "/homeless"))))
8793 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
8796 As can be guessed, this primitive is cumbersome to use directly. A
8797 better approach is to write build scripts in Scheme, of course! The
8798 best course of action for that is to write the build code as a
8799 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
8800 information, @pxref{G-Expressions}.
8802 Once upon a time, @code{gexp->derivation} did not exist and constructing
8803 derivations with build code written in Scheme was achieved with
8804 @code{build-expression->derivation}, documented below. This procedure
8805 is now deprecated in favor of the much nicer @code{gexp->derivation}.
8807 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
8808 @var{name} @var{exp} @
8809 [#:system (%current-system)] [#:inputs '()] @
8810 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8811 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8812 [#:references-graphs #f] [#:allowed-references #f] @
8813 [#:disallowed-references #f] @
8814 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
8815 Return a derivation that executes Scheme expression @var{exp} as a
8816 builder for derivation @var{name}. @var{inputs} must be a list of
8817 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
8818 @code{"out"} is assumed. @var{modules} is a list of names of Guile
8819 modules from the current search path to be copied in the store,
8820 compiled, and made available in the load path during the execution of
8821 @var{exp}---e.g., @code{((guix build utils) (guix build
8822 gnu-build-system))}.
8824 @var{exp} is evaluated in an environment where @code{%outputs} is bound
8825 to a list of output/path pairs, and where @code{%build-inputs} is bound
8826 to a list of string/output-path pairs made from @var{inputs}.
8827 Optionally, @var{env-vars} is a list of string pairs specifying the name
8828 and value of environment variables visible to the builder. The builder
8829 terminates by passing the result of @var{exp} to @code{exit}; thus, when
8830 @var{exp} returns @code{#f}, the build is considered to have failed.
8832 @var{exp} is built using @var{guile-for-build} (a derivation). When
8833 @var{guile-for-build} is omitted or is @code{#f}, the value of the
8834 @code{%guile-for-build} fluid is used instead.
8836 See the @code{derivation} procedure for the meaning of
8837 @var{references-graphs}, @var{allowed-references},
8838 @var{disallowed-references}, @var{local-build?}, and
8839 @var{substitutable?}.
8843 Here's an example of a single-output derivation that creates a directory
8844 containing one file:
8847 (let ((builder '(let ((out (assoc-ref %outputs "out")))
8848 (mkdir out) ; create /gnu/store/@dots{}-goo
8849 (call-with-output-file (string-append out "/test")
8851 (display '(hello guix) p))))))
8852 (build-expression->derivation store "goo" builder))
8854 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
8858 @node The Store Monad
8859 @section The Store Monad
8863 The procedures that operate on the store described in the previous
8864 sections all take an open connection to the build daemon as their first
8865 argument. Although the underlying model is functional, they either have
8866 side effects or depend on the current state of the store.
8868 The former is inconvenient: the connection to the build daemon has to be
8869 carried around in all those functions, making it impossible to compose
8870 functions that do not take that parameter with functions that do. The
8871 latter can be problematic: since store operations have side effects
8872 and/or depend on external state, they have to be properly sequenced.
8874 @cindex monadic values
8875 @cindex monadic functions
8876 This is where the @code{(guix monads)} module comes in. This module
8877 provides a framework for working with @dfn{monads}, and a particularly
8878 useful monad for our uses, the @dfn{store monad}. Monads are a
8879 construct that allows two things: associating ``context'' with values
8880 (in our case, the context is the store), and building sequences of
8881 computations (here computations include accesses to the store). Values
8882 in a monad---values that carry this additional context---are called
8883 @dfn{monadic values}; procedures that return such values are called
8884 @dfn{monadic procedures}.
8886 Consider this ``normal'' procedure:
8889 (define (sh-symlink store)
8890 ;; Return a derivation that symlinks the 'bash' executable.
8891 (let* ((drv (package-derivation store bash))
8892 (out (derivation->output-path drv))
8893 (sh (string-append out "/bin/bash")))
8894 (build-expression->derivation store "sh"
8895 `(symlink ,sh %output))))
8898 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
8899 as a monadic function:
8902 (define (sh-symlink)
8903 ;; Same, but return a monadic value.
8904 (mlet %store-monad ((drv (package->derivation bash)))
8905 (gexp->derivation "sh"
8906 #~(symlink (string-append #$drv "/bin/bash")
8910 There are several things to note in the second version: the @code{store}
8911 parameter is now implicit and is ``threaded'' in the calls to the
8912 @code{package->derivation} and @code{gexp->derivation} monadic
8913 procedures, and the monadic value returned by @code{package->derivation}
8914 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
8916 As it turns out, the call to @code{package->derivation} can even be
8917 omitted since it will take place implicitly, as we will see later
8918 (@pxref{G-Expressions}):
8921 (define (sh-symlink)
8922 (gexp->derivation "sh"
8923 #~(symlink (string-append #$bash "/bin/bash")
8928 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
8929 @c for the funny quote.
8930 Calling the monadic @code{sh-symlink} has no effect. As someone once
8931 said, ``you exit a monad like you exit a building on fire: by running''.
8932 So, to exit the monad and get the desired effect, one must use
8933 @code{run-with-store}:
8936 (run-with-store (open-connection) (sh-symlink))
8937 @result{} /gnu/store/...-sh-symlink
8940 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
8941 new ``meta-commands'' to make it easier to deal with monadic procedures:
8942 @code{run-in-store}, and @code{enter-store-monad}. The former is used
8943 to ``run'' a single monadic value through the store:
8946 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
8947 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
8950 The latter enters a recursive REPL, where all the return values are
8951 automatically run through the store:
8954 scheme@@(guile-user)> ,enter-store-monad
8955 store-monad@@(guile-user) [1]> (package->derivation hello)
8956 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
8957 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
8958 $3 = "/gnu/store/@dots{}-foo"
8959 store-monad@@(guile-user) [1]> ,q
8960 scheme@@(guile-user)>
8964 Note that non-monadic values cannot be returned in the
8965 @code{store-monad} REPL.
8967 The main syntactic forms to deal with monads in general are provided by
8968 the @code{(guix monads)} module and are described below.
8970 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
8971 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
8975 @deffn {Scheme Syntax} return @var{val}
8976 Return a monadic value that encapsulates @var{val}.
8979 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
8980 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
8981 procedures @var{mproc}@dots{}@footnote{This operation is commonly
8982 referred to as ``bind'', but that name denotes an unrelated procedure in
8983 Guile. Thus we use this somewhat cryptic symbol inherited from the
8984 Haskell language.}. There can be one @var{mproc} or several of them, as
8989 (with-monad %state-monad
8991 (lambda (x) (return (+ 1 x)))
8992 (lambda (x) (return (* 2 x)))))
8996 @result{} some-state
9000 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
9002 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
9004 Bind the variables @var{var} to the monadic values @var{mval} in
9005 @var{body}, which is a sequence of expressions. As with the bind
9006 operator, this can be thought of as ``unpacking'' the raw, non-monadic
9007 value ``contained'' in @var{mval} and making @var{var} refer to that
9008 raw, non-monadic value within the scope of the @var{body}. The form
9009 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
9010 @var{val}, as per @code{let}. The binding operations occur in sequence
9011 from left to right. The last expression of @var{body} must be a monadic
9012 expression, and its result will become the result of the @code{mlet} or
9013 @code{mlet*} when run in the @var{monad}.
9015 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
9016 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
9019 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
9020 Bind @var{mexp} and the following monadic expressions in sequence,
9021 returning the result of the last expression. Every expression in the
9022 sequence must be a monadic expression.
9024 This is akin to @code{mlet}, except that the return values of the
9025 monadic expressions are ignored. In that sense, it is analogous to
9026 @code{begin}, but applied to monadic expressions.
9029 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
9030 When @var{condition} is true, evaluate the sequence of monadic
9031 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9032 @var{condition} is false, return @code{*unspecified*} in the current
9033 monad. Every expression in the sequence must be a monadic expression.
9036 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
9037 When @var{condition} is false, evaluate the sequence of monadic
9038 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9039 @var{condition} is true, return @code{*unspecified*} in the current
9040 monad. Every expression in the sequence must be a monadic expression.
9044 The @code{(guix monads)} module provides the @dfn{state monad}, which
9045 allows an additional value---the state---to be @emph{threaded} through
9046 monadic procedure calls.
9048 @defvr {Scheme Variable} %state-monad
9049 The state monad. Procedures in the state monad can access and change
9050 the state that is threaded.
9052 Consider the example below. The @code{square} procedure returns a value
9053 in the state monad. It returns the square of its argument, but also
9054 increments the current state value:
9058 (mlet %state-monad ((count (current-state)))
9059 (mbegin %state-monad
9060 (set-current-state (+ 1 count))
9063 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
9068 When ``run'' through @code{%state-monad}, we obtain that additional state
9069 value, which is the number of @code{square} calls.
9072 @deffn {Monadic Procedure} current-state
9073 Return the current state as a monadic value.
9076 @deffn {Monadic Procedure} set-current-state @var{value}
9077 Set the current state to @var{value} and return the previous state as a
9081 @deffn {Monadic Procedure} state-push @var{value}
9082 Push @var{value} to the current state, which is assumed to be a list,
9083 and return the previous state as a monadic value.
9086 @deffn {Monadic Procedure} state-pop
9087 Pop a value from the current state and return it as a monadic value.
9088 The state is assumed to be a list.
9091 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
9092 Run monadic value @var{mval} starting with @var{state} as the initial
9093 state. Return two values: the resulting value, and the resulting state.
9096 The main interface to the store monad, provided by the @code{(guix
9097 store)} module, is as follows.
9099 @defvr {Scheme Variable} %store-monad
9100 The store monad---an alias for @code{%state-monad}.
9102 Values in the store monad encapsulate accesses to the store. When its
9103 effect is needed, a value of the store monad must be ``evaluated'' by
9104 passing it to the @code{run-with-store} procedure (see below).
9107 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
9108 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
9109 open store connection.
9112 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
9113 Return as a monadic value the absolute file name in the store of the file
9114 containing @var{text}, a string. @var{references} is a list of store items that the
9115 resulting text file refers to; it defaults to the empty list.
9118 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
9119 Return as a monadic value the absolute file name in the store of the file
9120 containing @var{data}, a bytevector. @var{references} is a list of store
9121 items that the resulting binary file refers to; it defaults to the empty list.
9124 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
9125 [#:recursive? #t] [#:select? (const #t)]
9126 Return the name of @var{file} once interned in the store. Use
9127 @var{name} as its store name, or the basename of @var{file} if
9128 @var{name} is omitted.
9130 When @var{recursive?} is true, the contents of @var{file} are added
9131 recursively; if @var{file} designates a flat file and @var{recursive?}
9132 is true, its contents are added, and its permission bits are kept.
9134 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9135 @var{stat})} for each directory entry, where @var{file} is the entry's
9136 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9137 entries for which @var{select?} does not return true.
9139 The example below adds a file to the store, under two different names:
9142 (run-with-store (open-connection)
9143 (mlet %store-monad ((a (interned-file "README"))
9144 (b (interned-file "README" "LEGU-MIN")))
9145 (return (list a b))))
9147 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
9152 The @code{(guix packages)} module exports the following package-related
9155 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
9156 [#:system (%current-system)] [#:target #f] @
9159 value in the absolute file name of @var{file} within the @var{output}
9160 directory of @var{package}. When @var{file} is omitted, return the name
9161 of the @var{output} directory of @var{package}. When @var{target} is
9162 true, use it as a cross-compilation target triplet.
9164 Note that this procedure does @emph{not} build @var{package}. Thus, the
9165 result might or might not designate an existing file. We recommend not
9166 using this procedure unless you know what you are doing.
9169 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
9170 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
9171 @var{target} [@var{system}]
9172 Monadic version of @code{package-derivation} and
9173 @code{package-cross-derivation} (@pxref{Defining Packages}).
9178 @section G-Expressions
9180 @cindex G-expression
9181 @cindex build code quoting
9182 So we have ``derivations'', which represent a sequence of build actions
9183 to be performed to produce an item in the store (@pxref{Derivations}).
9184 These build actions are performed when asking the daemon to actually
9185 build the derivations; they are run by the daemon in a container
9186 (@pxref{Invoking guix-daemon}).
9188 @cindex code staging
9189 @cindex staging, of code
9190 @cindex strata of code
9191 It should come as no surprise that we like to write these build actions
9192 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
9193 code@footnote{The term @dfn{stratum} in this context was coined by
9194 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
9195 Kiselyov, who has written insightful
9196 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
9197 on this topic}, refers to this kind of code generation as
9198 @dfn{staging}.}: the ``host code''---code that defines packages, talks
9199 to the daemon, etc.---and the ``build code''---code that actually
9200 performs build actions, such as making directories, invoking
9201 @command{make}, and so on (@pxref{Build Phases}).
9203 To describe a derivation and its build actions, one typically needs to
9204 embed build code inside host code. It boils down to manipulating build
9205 code as data, and the homoiconicity of Scheme---code has a direct
9206 representation as data---comes in handy for that. But we need more than
9207 the normal @code{quasiquote} mechanism in Scheme to construct build
9210 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
9211 S-expressions adapted to build expressions. G-expressions, or
9212 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
9213 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
9214 @code{#$}, and @code{#$@@}), which are comparable to
9215 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
9216 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
9217 GNU Guile Reference Manual}). However, there are major differences:
9221 Gexps are meant to be written to a file and run or manipulated by other
9225 When a high-level object such as a package or derivation is unquoted
9226 inside a gexp, the result is as if its output file name had been
9230 Gexps carry information about the packages or derivations they refer to,
9231 and these dependencies are automatically added as inputs to the build
9232 processes that use them.
9235 @cindex lowering, of high-level objects in gexps
9236 This mechanism is not limited to package and derivation
9237 objects: @dfn{compilers} able to ``lower'' other high-level objects to
9238 derivations or files in the store can be defined,
9239 such that these objects can also be inserted
9240 into gexps. For example, a useful type of high-level objects that can be
9241 inserted in a gexp is ``file-like objects'', which make it easy to
9242 add files to the store and to refer to them in
9243 derivations and such (see @code{local-file} and @code{plain-file}
9246 To illustrate the idea, here is an example of a gexp:
9253 (symlink (string-append #$coreutils "/bin/ls")
9257 This gexp can be passed to @code{gexp->derivation}; we obtain a
9258 derivation that builds a directory containing exactly one symlink to
9259 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
9262 (gexp->derivation "the-thing" build-exp)
9265 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
9266 substituted to the reference to the @var{coreutils} package in the
9267 actual build code, and @var{coreutils} is automatically made an input to
9268 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
9269 output)}) is replaced by a string containing the directory name of the
9270 output of the derivation.
9272 @cindex cross compilation
9273 In a cross-compilation context, it is useful to distinguish between
9274 references to the @emph{native} build of a package---that can run on the
9275 host---versus references to cross builds of a package. To that end, the
9276 @code{#+} plays the same role as @code{#$}, but is a reference to a
9277 native package build:
9280 (gexp->derivation "vi"
9283 (mkdir (string-append #$output "/bin"))
9284 (system* (string-append #+coreutils "/bin/ln")
9286 (string-append #$emacs "/bin/emacs")
9287 (string-append #$output "/bin/vi")))
9288 #:target "aarch64-linux-gnu")
9292 In the example above, the native build of @var{coreutils} is used, so
9293 that @command{ln} can actually run on the host; but then the
9294 cross-compiled build of @var{emacs} is referenced.
9296 @cindex imported modules, for gexps
9297 @findex with-imported-modules
9298 Another gexp feature is @dfn{imported modules}: sometimes you want to be
9299 able to use certain Guile modules from the ``host environment'' in the
9300 gexp, so those modules should be imported in the ``build environment''.
9301 The @code{with-imported-modules} form allows you to express that:
9304 (let ((build (with-imported-modules '((guix build utils))
9306 (use-modules (guix build utils))
9307 (mkdir-p (string-append #$output "/bin"))))))
9308 (gexp->derivation "empty-dir"
9311 (display "success!\n")
9316 In this example, the @code{(guix build utils)} module is automatically
9317 pulled into the isolated build environment of our gexp, such that
9318 @code{(use-modules (guix build utils))} works as expected.
9320 @cindex module closure
9321 @findex source-module-closure
9322 Usually you want the @emph{closure} of the module to be imported---i.e.,
9323 the module itself and all the modules it depends on---rather than just
9324 the module; failing to do that, attempts to use the module will fail
9325 because of missing dependent modules. The @code{source-module-closure}
9326 procedure computes the closure of a module by looking at its source file
9327 headers, which comes in handy in this case:
9330 (use-modules (guix modules)) ;for 'source-module-closure'
9332 (with-imported-modules (source-module-closure
9333 '((guix build utils)
9335 (gexp->derivation "something-with-vms"
9337 (use-modules (guix build utils)
9342 @cindex extensions, for gexps
9343 @findex with-extensions
9344 In the same vein, sometimes you want to import not just pure-Scheme
9345 modules, but also ``extensions'' such as Guile bindings to C libraries
9346 or other ``full-blown'' packages. Say you need the @code{guile-json}
9347 package available on the build side, here's how you would do it:
9350 (use-modules (gnu packages guile)) ;for 'guile-json'
9352 (with-extensions (list guile-json)
9353 (gexp->derivation "something-with-json"
9355 (use-modules (json))
9359 The syntactic form to construct gexps is summarized below.
9361 @deffn {Scheme Syntax} #~@var{exp}
9362 @deffnx {Scheme Syntax} (gexp @var{exp})
9363 Return a G-expression containing @var{exp}. @var{exp} may contain one
9364 or more of the following forms:
9368 @itemx (ungexp @var{obj})
9369 Introduce a reference to @var{obj}. @var{obj} may have one of the
9370 supported types, for example a package or a
9371 derivation, in which case the @code{ungexp} form is replaced by its
9372 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
9374 If @var{obj} is a list, it is traversed and references to supported
9375 objects are substituted similarly.
9377 If @var{obj} is another gexp, its contents are inserted and its
9378 dependencies are added to those of the containing gexp.
9380 If @var{obj} is another kind of object, it is inserted as is.
9382 @item #$@var{obj}:@var{output}
9383 @itemx (ungexp @var{obj} @var{output})
9384 This is like the form above, but referring explicitly to the
9385 @var{output} of @var{obj}---this is useful when @var{obj} produces
9386 multiple outputs (@pxref{Packages with Multiple Outputs}).
9389 @itemx #+@var{obj}:output
9390 @itemx (ungexp-native @var{obj})
9391 @itemx (ungexp-native @var{obj} @var{output})
9392 Same as @code{ungexp}, but produces a reference to the @emph{native}
9393 build of @var{obj} when used in a cross compilation context.
9395 @item #$output[:@var{output}]
9396 @itemx (ungexp output [@var{output}])
9397 Insert a reference to derivation output @var{output}, or to the main
9398 output when @var{output} is omitted.
9400 This only makes sense for gexps passed to @code{gexp->derivation}.
9403 @itemx (ungexp-splicing @var{lst})
9404 Like the above, but splices the contents of @var{lst} inside the
9408 @itemx (ungexp-native-splicing @var{lst})
9409 Like the above, but refers to native builds of the objects listed in
9414 G-expressions created by @code{gexp} or @code{#~} are run-time objects
9415 of the @code{gexp?} type (see below).
9418 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
9419 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
9420 in their execution environment.
9422 Each item in @var{modules} can be the name of a module, such as
9423 @code{(guix build utils)}, or it can be a module name, followed by an
9424 arrow, followed by a file-like object:
9427 `((guix build utils)
9429 ((guix config) => ,(scheme-file "config.scm"
9430 #~(define-module @dots{}))))
9434 In the example above, the first two modules are taken from the search
9435 path, and the last one is created from the given file-like object.
9437 This form has @emph{lexical} scope: it has an effect on the gexps
9438 directly defined in @var{body}@dots{}, but not on those defined, say, in
9439 procedures called from @var{body}@dots{}.
9442 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
9443 Mark the gexps defined in @var{body}@dots{} as requiring
9444 @var{extensions} in their build and execution environment.
9445 @var{extensions} is typically a list of package objects such as those
9446 defined in the @code{(gnu packages guile)} module.
9448 Concretely, the packages listed in @var{extensions} are added to the
9449 load path while compiling imported modules in @var{body}@dots{}; they
9450 are also added to the load path of the gexp returned by
9454 @deffn {Scheme Procedure} gexp? @var{obj}
9455 Return @code{#t} if @var{obj} is a G-expression.
9458 G-expressions are meant to be written to disk, either as code building
9459 some derivation, or as plain files in the store. The monadic procedures
9460 below allow you to do that (@pxref{The Store Monad}, for more
9461 information about monads).
9463 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
9464 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
9465 [#:hash #f] [#:hash-algo #f] @
9466 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
9467 [#:module-path @code{%load-path}] @
9468 [#:effective-version "2.2"] @
9469 [#:references-graphs #f] [#:allowed-references #f] @
9470 [#:disallowed-references #f] @
9471 [#:leaked-env-vars #f] @
9472 [#:script-name (string-append @var{name} "-builder")] @
9473 [#:deprecation-warnings #f] @
9474 [#:local-build? #f] [#:substitutable? #t] @
9475 [#:properties '()] [#:guile-for-build #f]
9476 Return a derivation @var{name} that runs @var{exp} (a gexp) with
9477 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
9478 stored in a file called @var{script-name}. When @var{target} is true,
9479 it is used as the cross-compilation target triplet for packages referred
9482 @var{modules} is deprecated in favor of @code{with-imported-modules}.
9484 make @var{modules} available in the evaluation context of @var{exp};
9485 @var{modules} is a list of names of Guile modules searched in
9486 @var{module-path} to be copied in the store, compiled, and made available in
9487 the load path during the execution of @var{exp}---e.g., @code{((guix
9488 build utils) (guix build gnu-build-system))}.
9490 @var{effective-version} determines the string to use when adding extensions of
9491 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
9493 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
9496 When @var{references-graphs} is true, it must be a list of tuples of one of the
9500 (@var{file-name} @var{package})
9501 (@var{file-name} @var{package} @var{output})
9502 (@var{file-name} @var{derivation})
9503 (@var{file-name} @var{derivation} @var{output})
9504 (@var{file-name} @var{store-item})
9507 The right-hand-side of each element of @var{references-graphs} is automatically made
9508 an input of the build process of @var{exp}. In the build environment, each
9509 @var{file-name} contains the reference graph of the corresponding item, in a simple
9512 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
9513 In the latter case, the list denotes store items that the result is allowed to
9514 refer to. Any reference to another store item will lead to a build error.
9515 Similarly for @var{disallowed-references}, which can list items that must not be
9516 referenced by the outputs.
9518 @var{deprecation-warnings} determines whether to show deprecation warnings while
9519 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
9521 The other arguments are as for @code{derivation} (@pxref{Derivations}).
9524 @cindex file-like objects
9525 The @code{local-file}, @code{plain-file}, @code{computed-file},
9526 @code{program-file}, and @code{scheme-file} procedures below return
9527 @dfn{file-like objects}. That is, when unquoted in a G-expression,
9528 these objects lead to a file in the store. Consider this G-expression:
9531 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
9532 #$(local-file "/tmp/my-nscd.conf"))
9535 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
9536 to the store. Once expanded, for instance @i{via}
9537 @code{gexp->derivation}, the G-expression refers to that copy under
9538 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
9539 does not have any effect on what the G-expression does.
9540 @code{plain-file} can be used similarly; it differs in that the file
9541 content is directly passed as a string.
9543 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
9544 [#:recursive? #f] [#:select? (const #t)]
9545 Return an object representing local file @var{file} to add to the store;
9546 this object can be used in a gexp. If @var{file} is a literal string
9547 denoting a relative file name, it is looked up relative to the source
9548 file where it appears; if @var{file} is not a literal string, it is
9549 looked up relative to the current working directory at run time.
9550 @var{file} will be added to the store under @var{name}--by default the
9551 base name of @var{file}.
9553 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
9554 designates a flat file and @var{recursive?} is true, its contents are added, and its
9555 permission bits are kept.
9557 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9558 @var{stat})} for each directory entry, where @var{file} is the entry's
9559 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9560 entries for which @var{select?} does not return true.
9562 This is the declarative counterpart of the @code{interned-file} monadic
9563 procedure (@pxref{The Store Monad, @code{interned-file}}).
9566 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
9567 Return an object representing a text file called @var{name} with the given
9568 @var{content} (a string or a bytevector) to be added to the store.
9570 This is the declarative counterpart of @code{text-file}.
9573 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
9576 Return an object representing the store item @var{name}, a file or
9577 directory computed by @var{gexp}. When @var{local-build?} is true (the
9578 default), the derivation is built locally. @var{options} is a list of
9579 additional arguments to pass to @code{gexp->derivation}.
9581 This is the declarative counterpart of @code{gexp->derivation}.
9584 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
9585 [#:guile (default-guile)] [#:module-path %load-path] @
9586 [#:system (%current-system)] [#:target #f]
9587 Return an executable script @var{name} that runs @var{exp} using
9588 @var{guile}, with @var{exp}'s imported modules in its search path.
9589 Look up @var{exp}'s modules in @var{module-path}.
9591 The example below builds a script that simply invokes the @command{ls}
9595 (use-modules (guix gexp) (gnu packages base))
9597 (gexp->script "list-files"
9598 #~(execl #$(file-append coreutils "/bin/ls")
9602 When ``running'' it through the store (@pxref{The Store Monad,
9603 @code{run-with-store}}), we obtain a derivation that produces an
9604 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
9607 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
9609 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
9613 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
9614 [#:guile #f] [#:module-path %load-path]
9615 Return an object representing the executable store item @var{name} that
9616 runs @var{gexp}. @var{guile} is the Guile package used to execute that
9617 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
9619 This is the declarative counterpart of @code{gexp->script}.
9622 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
9623 [#:set-load-path? #t] [#:module-path %load-path] @
9625 [#:guile (default-guile)]
9626 Return a derivation that builds a file @var{name} containing @var{exp}.
9627 When @var{splice?} is true, @var{exp} is considered to be a list of
9628 expressions that will be spliced in the resulting file.
9630 When @var{set-load-path?} is true, emit code in the resulting file to
9631 set @code{%load-path} and @code{%load-compiled-path} to honor
9632 @var{exp}'s imported modules. Look up @var{exp}'s modules in
9635 The resulting file holds references to all the dependencies of @var{exp}
9636 or a subset thereof.
9639 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
9640 [#:splice? #f] [#:set-load-path? #t]
9641 Return an object representing the Scheme file @var{name} that contains
9644 This is the declarative counterpart of @code{gexp->file}.
9647 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
9648 Return as a monadic value a derivation that builds a text file
9649 containing all of @var{text}. @var{text} may list, in addition to
9650 strings, objects of any type that can be used in a gexp: packages,
9651 derivations, local file objects, etc. The resulting store file holds
9652 references to all these.
9654 This variant should be preferred over @code{text-file} anytime the file
9655 to create will reference items from the store. This is typically the
9656 case when building a configuration file that embeds store file names,
9660 (define (profile.sh)
9661 ;; Return the name of a shell script in the store that
9662 ;; initializes the 'PATH' environment variable.
9663 (text-file* "profile.sh"
9664 "export PATH=" coreutils "/bin:"
9665 grep "/bin:" sed "/bin\n"))
9668 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
9669 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
9670 preventing them from being garbage-collected during its lifetime.
9673 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
9674 Return an object representing store file @var{name} containing
9675 @var{text}. @var{text} is a sequence of strings and file-like objects,
9679 (mixed-text-file "profile"
9680 "export PATH=" coreutils "/bin:" grep "/bin")
9683 This is the declarative counterpart of @code{text-file*}.
9686 @deffn {Scheme Procedure} file-union @var{name} @var{files}
9687 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
9688 Each item in @var{files} must be a two-element list where the first element is the
9689 file name to use in the new directory, and the second element is a gexp
9690 denoting the target file. Here's an example:
9694 `(("hosts" ,(plain-file "hosts"
9695 "127.0.0.1 localhost"))
9696 ("bashrc" ,(plain-file "bashrc"
9697 "alias ls='ls --color=auto'"))))
9700 This yields an @code{etc} directory containing these two files.
9703 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
9704 Return a directory that is the union of @var{things}, where @var{things} is a list of
9705 file-like objects denoting directories. For example:
9708 (directory-union "guile+emacs" (list guile emacs))
9711 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
9714 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
9715 Return a file-like object that expands to the concatenation of @var{obj}
9716 and @var{suffix}, where @var{obj} is a lowerable object and each
9717 @var{suffix} is a string.
9719 As an example, consider this gexp:
9722 (gexp->script "run-uname"
9723 #~(system* #$(file-append coreutils
9727 The same effect could be achieved with:
9730 (gexp->script "run-uname"
9731 #~(system* (string-append #$coreutils
9735 There is one difference though: in the @code{file-append} case, the
9736 resulting script contains the absolute file name as a string, whereas in
9737 the second case, the resulting script contains a @code{(string-append
9738 @dots{})} expression to construct the file name @emph{at run time}.
9741 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
9742 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
9743 Bind @var{system} to the currently targeted system---e.g.,
9744 @code{"x86_64-linux"}---within @var{body}.
9746 In the second case, additionally bind @var{target} to the current
9747 cross-compilation target---a GNU triplet such as
9748 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
9751 @code{let-system} is useful in the occasional case where the object
9752 spliced into the gexp depends on the target system, as in this example:
9756 #+(let-system system
9757 (cond ((string-prefix? "armhf-" system)
9758 (file-append qemu "/bin/qemu-system-arm"))
9759 ((string-prefix? "x86_64-" system)
9760 (file-append qemu "/bin/qemu-system-x86_64"))
9763 "-net" "user" #$image)
9767 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
9768 This macro is similar to the @code{parameterize} form for
9769 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
9770 Guile Reference Manual}). The key difference is that it takes effect
9771 when the file-like object returned by @var{exp} is lowered to a
9772 derivation or store item.
9774 A typical use of @code{with-parameters} is to force the system in effect
9778 (with-parameters ((%current-system "i686-linux"))
9782 The example above returns an object that corresponds to the i686 build
9783 of Coreutils, regardless of the current value of @code{%current-system}.
9787 Of course, in addition to gexps embedded in ``host'' code, there are
9788 also modules containing build tools. To make it clear that they are
9789 meant to be used in the build stratum, these modules are kept in the
9790 @code{(guix build @dots{})} name space.
9792 @cindex lowering, of high-level objects in gexps
9793 Internally, high-level objects are @dfn{lowered}, using their compiler,
9794 to either derivations or store items. For instance, lowering a package
9795 yields a derivation, and lowering a @code{plain-file} yields a store
9796 item. This is achieved using the @code{lower-object} monadic procedure.
9798 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
9800 Return as a value in @code{%store-monad} the derivation or store item
9801 corresponding to @var{obj} for @var{system}, cross-compiling for
9802 @var{target} if @var{target} is true. @var{obj} must be an object that
9803 has an associated gexp compiler, such as a @code{<package>}.
9806 @node Invoking guix repl
9807 @section Invoking @command{guix repl}
9809 @cindex REPL, read-eval-print loop, script
9810 The @command{guix repl} command makes it easier to program Guix in Guile
9811 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
9812 programming (@pxref{Using Guile Interactively,,, guile,
9813 GNU Guile Reference Manual}), or by running Guile scripts
9814 (@pxref{Running Guile Scripts,,, guile,
9815 GNU Guile Reference Manual}).
9816 Compared to just launching the @command{guile}
9817 command, @command{guix repl} guarantees that all the Guix modules and all its
9818 dependencies are available in the search path.
9820 The general syntax is:
9823 guix repl @var{options} [@var{file} @var{args}]
9826 When a @var{file} argument is provided, @var{file} is
9827 executed as a Guile scripts:
9830 guix repl my-script.scm
9833 To pass arguments to the script, use @code{--} to prevent them from
9834 being interpreted as arguments to @command{guix repl} itself:
9837 guix repl -- my-script.scm --input=foo.txt
9840 To make a script executable directly from the shell, using the guix
9841 executable that is on the user's search path, add the following two
9842 lines at the top of the script:
9845 @code{#!/usr/bin/env -S guix repl --}
9849 Without a file name argument, a Guile REPL is started:
9853 scheme@@(guile-user)> ,use (gnu packages base)
9854 scheme@@(guile-user)> coreutils
9855 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
9859 In addition, @command{guix repl} implements a simple machine-readable REPL
9860 protocol for use by @code{(guix inferior)}, a facility to interact with
9861 @dfn{inferiors}, separate processes running a potentially different revision
9864 The available options are as follows:
9867 @item --type=@var{type}
9868 @itemx -t @var{type}
9869 Start a REPL of the given @var{TYPE}, which can be one of the following:
9873 This is default, and it spawns a standard full-featured Guile REPL.
9875 Spawn a REPL that uses the machine-readable protocol. This is the protocol
9876 that the @code{(guix inferior)} module speaks.
9879 @item --listen=@var{endpoint}
9880 By default, @command{guix repl} reads from standard input and writes to
9881 standard output. When this option is passed, it will instead listen for
9882 connections on @var{endpoint}. Here are examples of valid options:
9885 @item --listen=tcp:37146
9886 Accept connections on localhost on port 37146.
9888 @item --listen=unix:/tmp/socket
9889 Accept connections on the Unix-domain socket @file{/tmp/socket}.
9892 @item --load-path=@var{directory}
9893 @itemx -L @var{directory}
9894 Add @var{directory} to the front of the package module search path
9895 (@pxref{Package Modules}).
9897 This allows users to define their own packages and make them visible to
9901 Inhibit loading of the @file{~/.guile} file. By default, that
9902 configuration file is loaded when spawning a @code{guile} REPL.
9905 @c *********************************************************************
9909 This section describes Guix command-line utilities. Some of them are
9910 primarily targeted at developers and users who write new package
9911 definitions, while others are more generally useful. They complement
9912 the Scheme programming interface of Guix in a convenient way.
9915 * Invoking guix build:: Building packages from the command line.
9916 * Invoking guix edit:: Editing package definitions.
9917 * Invoking guix download:: Downloading a file and printing its hash.
9918 * Invoking guix hash:: Computing the cryptographic hash of a file.
9919 * Invoking guix import:: Importing package definitions.
9920 * Invoking guix refresh:: Updating package definitions.
9921 * Invoking guix lint:: Finding errors in package definitions.
9922 * Invoking guix size:: Profiling disk usage.
9923 * Invoking guix graph:: Visualizing the graph of packages.
9924 * Invoking guix publish:: Sharing substitutes.
9925 * Invoking guix challenge:: Challenging substitute servers.
9926 * Invoking guix copy:: Copying to and from a remote store.
9927 * Invoking guix container:: Process isolation.
9928 * Invoking guix weather:: Assessing substitute availability.
9929 * Invoking guix processes:: Listing client processes.
9932 @node Invoking guix build
9933 @section Invoking @command{guix build}
9935 @cindex package building
9936 @cindex @command{guix build}
9937 The @command{guix build} command builds packages or derivations and
9938 their dependencies, and prints the resulting store paths. Note that it
9939 does not modify the user's profile---this is the job of the
9940 @command{guix package} command (@pxref{Invoking guix package}). Thus,
9941 it is mainly useful for distribution developers.
9943 The general syntax is:
9946 guix build @var{options} @var{package-or-derivation}@dots{}
9949 As an example, the following command builds the latest versions of Emacs
9950 and of Guile, displays their build logs, and finally displays the
9951 resulting directories:
9954 guix build emacs guile
9957 Similarly, the following command builds all the available packages:
9960 guix build --quiet --keep-going \
9961 `guix package -A | cut -f1,2 --output-delimiter=@@`
9964 @var{package-or-derivation} may be either the name of a package found in
9965 the software distribution such as @code{coreutils} or
9966 @code{coreutils@@8.20}, or a derivation such as
9967 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
9968 package with the corresponding name (and optionally version) is searched
9969 for among the GNU distribution modules (@pxref{Package Modules}).
9971 Alternatively, the @option{--expression} option may be used to specify a
9972 Scheme expression that evaluates to a package; this is useful when
9973 disambiguating among several same-named packages or package variants is
9976 There may be zero or more @var{options}. The available options are
9977 described in the subsections below.
9980 * Common Build Options:: Build options for most commands.
9981 * Package Transformation Options:: Creating variants of packages.
9982 * Additional Build Options:: Options specific to 'guix build'.
9983 * Debugging Build Failures:: Real life packaging experience.
9986 @node Common Build Options
9987 @subsection Common Build Options
9989 A number of options that control the build process are common to
9990 @command{guix build} and other commands that can spawn builds, such as
9991 @command{guix package} or @command{guix archive}. These are the
9996 @item --load-path=@var{directory}
9997 @itemx -L @var{directory}
9998 Add @var{directory} to the front of the package module search path
9999 (@pxref{Package Modules}).
10001 This allows users to define their own packages and make them visible to
10002 the command-line tools.
10004 @item --keep-failed
10006 Keep the build tree of failed builds. Thus, if a build fails, its build
10007 tree is kept under @file{/tmp}, in a directory whose name is shown at
10008 the end of the build log. This is useful when debugging build issues.
10009 @xref{Debugging Build Failures}, for tips and tricks on how to debug
10012 This option implies @option{--no-offload}, and it has no effect when
10013 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
10014 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
10018 Keep going when some of the derivations fail to build; return only once
10019 all the builds have either completed or failed.
10021 The default behavior is to stop as soon as one of the specified
10022 derivations has failed.
10026 Do not build the derivations.
10028 @anchor{fallback-option}
10030 When substituting a pre-built binary fails, fall back to building
10031 packages locally (@pxref{Substitution Failure}).
10033 @item --substitute-urls=@var{urls}
10034 @anchor{client-substitute-urls}
10035 Consider @var{urls} the whitespace-separated list of substitute source
10036 URLs, overriding the default list of URLs of @command{guix-daemon}
10037 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
10039 This means that substitutes may be downloaded from @var{urls}, provided
10040 they are signed by a key authorized by the system administrator
10041 (@pxref{Substitutes}).
10043 When @var{urls} is the empty string, substitutes are effectively
10046 @item --no-substitutes
10047 Do not use substitutes for build products. That is, always build things
10048 locally instead of allowing downloads of pre-built binaries
10049 (@pxref{Substitutes}).
10052 Do not ``graft'' packages. In practice, this means that package updates
10053 available as grafts are not applied. @xref{Security Updates}, for more
10054 information on grafts.
10056 @item --rounds=@var{n}
10057 Build each derivation @var{n} times in a row, and raise an error if
10058 consecutive build results are not bit-for-bit identical.
10060 This is a useful way to detect non-deterministic builds processes.
10061 Non-deterministic build processes are a problem because they make it
10062 practically impossible for users to @emph{verify} whether third-party
10063 binaries are genuine. @xref{Invoking guix challenge}, for more.
10065 When used in conjunction with @option{--keep-failed}, the differing
10066 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10067 This makes it easy to look for differences between the two results.
10070 Do not use offload builds to other machines (@pxref{Daemon Offload
10071 Setup}). That is, always build things locally instead of offloading
10072 builds to remote machines.
10074 @item --max-silent-time=@var{seconds}
10075 When the build or substitution process remains silent for more than
10076 @var{seconds}, terminate it and report a build failure.
10078 By default, the daemon's setting is honored (@pxref{Invoking
10079 guix-daemon, @option{--max-silent-time}}).
10081 @item --timeout=@var{seconds}
10082 Likewise, when the build or substitution process lasts for more than
10083 @var{seconds}, terminate it and report a build failure.
10085 By default, the daemon's setting is honored (@pxref{Invoking
10086 guix-daemon, @option{--timeout}}).
10088 @c Note: This option is actually not part of %standard-build-options but
10089 @c most programs honor it.
10090 @cindex verbosity, of the command-line tools
10091 @cindex build logs, verbosity
10092 @item -v @var{level}
10093 @itemx --verbosity=@var{level}
10094 Use the given verbosity @var{level}, an integer. Choosing 0 means that no
10095 output is produced, 1 is for quiet output, and 2 shows all the build log
10096 output on standard error.
10098 @item --cores=@var{n}
10100 Allow the use of up to @var{n} CPU cores for the build. The special
10101 value @code{0} means to use as many CPU cores as available.
10103 @item --max-jobs=@var{n}
10105 Allow at most @var{n} build jobs in parallel. @xref{Invoking
10106 guix-daemon, @option{--max-jobs}}, for details about this option and the
10107 equivalent @command{guix-daemon} option.
10109 @item --debug=@var{level}
10110 Produce debugging output coming from the build daemon. @var{level} must be an
10111 integer between 0 and 5; higher means more verbose output. Setting a level of
10112 4 or more may be helpful when debugging setup issues with the build daemon.
10116 Behind the scenes, @command{guix build} is essentially an interface to
10117 the @code{package-derivation} procedure of the @code{(guix packages)}
10118 module, and to the @code{build-derivations} procedure of the @code{(guix
10119 derivations)} module.
10121 In addition to options explicitly passed on the command line,
10122 @command{guix build} and other @command{guix} commands that support
10123 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
10125 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
10126 Users can define this variable to a list of command line options that
10127 will automatically be used by @command{guix build} and other
10128 @command{guix} commands that can perform builds, as in the example
10132 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
10135 These options are parsed independently, and the result is appended to
10136 the parsed command-line options.
10140 @node Package Transformation Options
10141 @subsection Package Transformation Options
10143 @cindex package variants
10144 Another set of command-line options supported by @command{guix build}
10145 and also @command{guix package} are @dfn{package transformation
10146 options}. These are options that make it possible to define @dfn{package
10147 variants}---for instance, packages built from different source code.
10148 This is a convenient way to create customized packages on the fly
10149 without having to type in the definitions of package variants
10150 (@pxref{Defining Packages}).
10152 Package transformation options are preserved across upgrades:
10153 @command{guix upgrade} attempts to apply transformation options
10154 initially used when creating the profile to the upgraded packages.
10156 The available options are listed below. Most commands support them and
10157 also support a @option{--help-transform} option that lists all the
10158 available options and a synopsis (these options are not shown in the
10159 @option{--help} output for brevity).
10163 @item --with-source=@var{source}
10164 @itemx --with-source=@var{package}=@var{source}
10165 @itemx --with-source=@var{package}@@@var{version}=@var{source}
10166 Use @var{source} as the source of @var{package}, and @var{version} as
10167 its version number.
10168 @var{source} must be a file name or a URL, as for @command{guix
10169 download} (@pxref{Invoking guix download}).
10171 When @var{package} is omitted,
10172 it is taken to be the package name specified on the
10173 command line that matches the base of @var{source}---e.g.,
10174 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
10175 package is @code{guile}.
10177 Likewise, when @var{version} is omitted, the version string is inferred from
10178 @var{source}; in the previous example, it is @code{2.0.10}.
10180 This option allows users to try out versions of packages other than the
10181 one provided by the distribution. The example below downloads
10182 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
10183 the @code{ed} package:
10186 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
10189 As a developer, @option{--with-source} makes it easy to test release
10193 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
10196 @dots{} or to build from a checkout in a pristine environment:
10199 $ git clone git://git.sv.gnu.org/guix.git
10200 $ guix build guix --with-source=guix@@1.0=./guix
10203 @item --with-input=@var{package}=@var{replacement}
10204 Replace dependency on @var{package} by a dependency on
10205 @var{replacement}. @var{package} must be a package name, and
10206 @var{replacement} must be a package specification such as @code{guile}
10207 or @code{guile@@1.8}.
10209 For instance, the following command builds Guix, but replaces its
10210 dependency on the current stable version of Guile with a dependency on
10211 the legacy version of Guile, @code{guile@@2.0}:
10214 guix build --with-input=guile=guile@@2.0 guix
10217 This is a recursive, deep replacement. So in this example, both
10218 @code{guix} and its dependency @code{guile-json} (which also depends on
10219 @code{guile}) get rebuilt against @code{guile@@2.0}.
10221 This is implemented using the @code{package-input-rewriting} Scheme
10222 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
10224 @item --with-graft=@var{package}=@var{replacement}
10225 This is similar to @option{--with-input} but with an important difference:
10226 instead of rebuilding the whole dependency chain, @var{replacement} is
10227 built and then @dfn{grafted} onto the binaries that were initially
10228 referring to @var{package}. @xref{Security Updates}, for more
10229 information on grafts.
10231 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
10232 and all its dependencies, replacing references to the version of GnuTLS
10233 they currently refer to:
10236 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
10239 This has the advantage of being much faster than rebuilding everything.
10240 But there is a caveat: it works if and only if @var{package} and
10241 @var{replacement} are strictly compatible---for example, if they provide
10242 a library, the application binary interface (ABI) of those libraries
10243 must be compatible. If @var{replacement} is somehow incompatible with
10244 @var{package}, then the resulting package may be unusable. Use with
10247 @cindex debugging info, rebuilding
10248 @item --with-debug-info=@var{package}
10249 Build @var{package} in a way that preserves its debugging info and graft
10250 it onto packages that depend on it. This is useful if @var{package}
10251 does not already provide debugging info as a @code{debug} output
10252 (@pxref{Installing Debugging Files}).
10254 For example, suppose you're experiencing a crash in Inkscape and would
10255 like to see what's up in GLib, a library deep down in Inkscape's
10256 dependency graph. GLib lacks a @code{debug} output, so debugging is
10257 tough. Fortunately, you rebuild GLib with debugging info and tack it on
10261 guix install inkscape --with-debug-info=glib
10264 Only GLib needs to be recompiled so this takes a reasonable amount of
10265 time. @xref{Installing Debugging Files}, for more info.
10268 Under the hood, this option works by passing the @samp{#:strip-binaries?
10269 #f} to the build system of the package of interest (@pxref{Build
10270 Systems}). Most build systems support that option but some do not. In
10271 that case, an error is raised.
10273 Likewise, if a C/C++ package is built without @code{-g} (which is rarely
10274 the case), debugging info will remain unavailable even when
10275 @code{#:strip-binaries?} is false.
10278 @cindex tool chain, changing the build tool chain of a package
10279 @item --with-c-toolchain=@var{package}=@var{toolchain}
10280 This option changes the compilation of @var{package} and everything that
10281 depends on it so that they get built with @var{toolchain} instead of the
10282 default GNU tool chain for C/C++.
10284 Consider this example:
10287 guix build octave-cli \
10288 --with-c-toolchain=fftw=gcc-toolchain@@10 \
10289 --with-c-toolchain=fftwf=gcc-toolchain@@10
10292 The command above builds a variant of the @code{fftw} and @code{fftwf}
10293 packages using version 10 of @code{gcc-toolchain} instead of the default
10294 tool chain, and then builds a variant of the GNU@tie{}Octave
10295 command-line interface using them. GNU@tie{}Octave itself is also built
10296 with @code{gcc-toolchain@@10}.
10298 This other example builds the Hardware Locality (@code{hwloc}) library
10299 and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
10303 guix build --with-c-toolchain=hwloc=clang-toolchain \
10304 intel-mpi-benchmarks
10308 There can be application binary interface (ABI) incompatibilities among
10309 tool chains. This is particularly true of the C++ standard library and
10310 run-time support libraries such as that of OpenMP. By rebuilding all
10311 dependents with the same tool chain, @option{--with-c-toolchain} minimizes
10312 the risks of incompatibility but cannot entirely eliminate them. Choose
10313 @var{package} wisely.
10316 @item --with-git-url=@var{package}=@var{url}
10317 @cindex Git, using the latest commit
10318 @cindex latest commit, building
10319 Build @var{package} from the latest commit of the @code{master} branch of the
10320 Git repository at @var{url}. Git sub-modules of the repository are fetched,
10323 For example, the following command builds the NumPy Python library against the
10324 latest commit of the master branch of Python itself:
10327 guix build python-numpy \
10328 --with-git-url=python=https://github.com/python/cpython
10331 This option can also be combined with @option{--with-branch} or
10332 @option{--with-commit} (see below).
10334 @cindex continuous integration
10335 Obviously, since it uses the latest commit of the given branch, the result of
10336 such a command varies over time. Nevertheless it is a convenient way to
10337 rebuild entire software stacks against the latest commit of one or more
10338 packages. This is particularly useful in the context of continuous
10341 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
10342 consecutive accesses to the same repository. You may want to clean it up once
10343 in a while to save disk space.
10345 @item --with-branch=@var{package}=@var{branch}
10346 Build @var{package} from the latest commit of @var{branch}. If the
10347 @code{source} field of @var{package} is an origin with the @code{git-fetch}
10348 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
10349 repository URL is taken from that @code{source}. Otherwise you have to use
10350 @option{--with-git-url} to specify the URL of the Git repository.
10352 For instance, the following command builds @code{guile-sqlite3} from the
10353 latest commit of its @code{master} branch, and then builds @code{guix} (which
10354 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
10355 specific @code{guile-sqlite3} build:
10358 guix build --with-branch=guile-sqlite3=master cuirass
10361 @item --with-commit=@var{package}=@var{commit}
10362 This is similar to @option{--with-branch}, except that it builds from
10363 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
10364 Git commit SHA1 identifier or a tag.
10366 @item --with-patch=@var{package}=@var{file}
10367 Add @var{file} to the list of patches applied to @var{package}, where
10368 @var{package} is a spec such as @code{python@@3.8} or @code{glibc}.
10369 @var{file} must contain a patch; it is applied with the flags specified
10370 in the @code{origin} of @var{package} (@pxref{origin Reference}), which
10371 by default includes @code{-p1} (@pxref{patch Directories,,, diffutils,
10372 Comparing and Merging Files}).
10374 As an example, the command below rebuilds Coreutils with the GNU C
10375 Library (glibc) patched with the given patch:
10378 guix build coreutils --with-patch=glibc=./glibc-frob.patch
10381 In this example, glibc itself as well as everything that leads to
10382 Coreutils in the dependency graph is rebuilt.
10384 @cindex test suite, skipping
10385 @item --without-tests=@var{package}
10386 Build @var{package} without running its tests. This can be useful in
10387 situations where you want to skip the lengthy test suite of a
10388 intermediate package, or if a package's test suite fails in a
10389 non-deterministic fashion. It should be used with care because running
10390 the test suite is a good way to ensure a package is working as intended.
10392 Turning off tests leads to a different store item. Consequently, when
10393 using this option, anything that depends on @var{package} must be
10394 rebuilt, as in this example:
10397 guix install --without-tests=python python-notebook
10400 The command above installs @code{python-notebook} on top of
10401 @code{python} built without running its test suite. To do so, it also
10402 rebuilds everything that depends on @code{python}, including
10403 @code{python-notebook} itself.
10405 Internally, @option{--without-tests} relies on changing the
10406 @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
10407 Systems}). Note that some packages use a customized @code{check} phase
10408 that does not respect a @code{#:tests? #f} setting. Therefore,
10409 @option{--without-tests} has no effect on these packages.
10413 Wondering how to achieve the same effect using Scheme code, for example
10414 in your manifest, or how to write your own package transformation?
10415 @xref{Defining Package Variants}, for an overview of the programming
10416 interfaces available.
10418 @node Additional Build Options
10419 @subsection Additional Build Options
10421 The command-line options presented below are specific to @command{guix
10428 Build quietly, without displaying the build log; this is equivalent to
10429 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
10430 (or similar) and can always be retrieved using the @option{--log-file} option.
10432 @item --file=@var{file}
10433 @itemx -f @var{file}
10434 Build the package, derivation, or other file-like object that the code within
10435 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
10437 As an example, @var{file} might contain a package definition like this
10438 (@pxref{Defining Packages}):
10441 @include package-hello.scm
10444 The @var{file} may also contain a JSON representation of one or more
10445 package definitions. Running @code{guix build -f} on @file{hello.json}
10446 with the following contents would result in building the packages
10447 @code{myhello} and @code{greeter}:
10450 @verbatiminclude package-hello.json
10453 @item --manifest=@var{manifest}
10454 @itemx -m @var{manifest}
10455 Build all packages listed in the given @var{manifest}
10456 (@pxref{profile-manifest, @option{--manifest}}).
10458 @item --expression=@var{expr}
10459 @itemx -e @var{expr}
10460 Build the package or derivation @var{expr} evaluates to.
10462 For example, @var{expr} may be @code{(@@ (gnu packages guile)
10463 guile-1.8)}, which unambiguously designates this specific variant of
10464 version 1.8 of Guile.
10466 Alternatively, @var{expr} may be a G-expression, in which case it is used
10467 as a build program passed to @code{gexp->derivation}
10468 (@pxref{G-Expressions}).
10470 Lastly, @var{expr} may refer to a zero-argument monadic procedure
10471 (@pxref{The Store Monad}). The procedure must return a derivation as a
10472 monadic value, which is then passed through @code{run-with-store}.
10476 Build the source derivations of the packages, rather than the packages
10479 For instance, @code{guix build -S gcc} returns something like
10480 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
10483 The returned source tarball is the result of applying any patches and
10484 code snippets specified in the package @code{origin} (@pxref{Defining
10487 @cindex source, verification
10488 As with other derivations, the result of building a source derivation
10489 can be verified using the @option{--check} option (@pxref{build-check}).
10490 This is useful to validate that a (potentially already built or
10491 substituted, thus cached) package source matches against its declared
10494 Note that @command{guix build -S} compiles the sources only of the
10495 specified packages. They do not include the sources of statically
10496 linked dependencies and by themselves are insufficient for reproducing
10500 Fetch and return the source of @var{package-or-derivation} and all their
10501 dependencies, recursively. This is a handy way to obtain a local copy
10502 of all the source code needed to build @var{packages}, allowing you to
10503 eventually build them even without network access. It is an extension
10504 of the @option{--source} option and can accept one of the following
10505 optional argument values:
10509 This value causes the @option{--sources} option to behave in the same way
10510 as the @option{--source} option.
10513 Build the source derivations of all packages, including any source that
10514 might be listed as @code{inputs}. This is the default value.
10517 $ guix build --sources tzdata
10518 The following derivations will be built:
10519 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
10520 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10524 Build the source derivations of all packages, as well of all transitive
10525 inputs to the packages. This can be used e.g.@: to
10526 prefetch package source for later offline building.
10529 $ guix build --sources=transitive tzdata
10530 The following derivations will be built:
10531 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10532 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
10533 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
10534 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
10535 /gnu/store/@dots{}-make-4.1.tar.xz.drv
10536 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
10542 @item --system=@var{system}
10543 @itemx -s @var{system}
10544 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
10545 the system type of the build host. The @command{guix build} command allows
10546 you to repeat this option several times, in which case it builds for all the
10547 specified systems; other commands ignore extraneous @option{-s} options.
10550 The @option{--system} flag is for @emph{native} compilation and must not
10551 be confused with cross-compilation. See @option{--target} below for
10552 information on cross-compilation.
10555 An example use of this is on Linux-based systems, which can emulate
10556 different personalities. For instance, passing
10557 @option{--system=i686-linux} on an @code{x86_64-linux} system or
10558 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
10559 you to build packages in a complete 32-bit environment.
10562 Building for an @code{armhf-linux} system is unconditionally enabled on
10563 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
10564 allow for this functionality, notably the ThunderX.
10567 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
10568 is enabled (@pxref{Virtualization Services,
10569 @code{qemu-binfmt-service-type}}), you can build for any system for
10570 which a QEMU @code{binfmt_misc} handler is installed.
10572 Builds for a system other than that of the machine you are using can
10573 also be offloaded to a remote machine of the right architecture.
10574 @xref{Daemon Offload Setup}, for more information on offloading.
10576 @item --target=@var{triplet}
10577 @cindex cross-compilation
10578 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
10579 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
10580 configuration triplets,, autoconf, Autoconf}).
10582 @anchor{build-check}
10584 @cindex determinism, checking
10585 @cindex reproducibility, checking
10586 Rebuild @var{package-or-derivation}, which are already available in the
10587 store, and raise an error if the build results are not bit-for-bit
10590 This mechanism allows you to check whether previously installed
10591 substitutes are genuine (@pxref{Substitutes}), or whether the build result
10592 of a package is deterministic. @xref{Invoking guix challenge}, for more
10593 background information and tools.
10595 When used in conjunction with @option{--keep-failed}, the differing
10596 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10597 This makes it easy to look for differences between the two results.
10600 @cindex repairing store items
10601 @cindex corruption, recovering from
10602 Attempt to repair the specified store items, if they are corrupt, by
10603 re-downloading or rebuilding them.
10605 This operation is not atomic and thus restricted to @code{root}.
10607 @item --derivations
10609 Return the derivation paths, not the output paths, of the given
10612 @item --root=@var{file}
10613 @itemx -r @var{file}
10614 @cindex GC roots, adding
10615 @cindex garbage collector roots, adding
10616 Make @var{file} a symlink to the result, and register it as a garbage
10619 Consequently, the results of this @command{guix build} invocation are
10620 protected from garbage collection until @var{file} is removed. When
10621 that option is omitted, build results are eligible for garbage
10622 collection as soon as the build completes. @xref{Invoking guix gc}, for
10626 @cindex build logs, access
10627 Return the build log file names or URLs for the given
10628 @var{package-or-derivation}, or raise an error if build logs are
10631 This works regardless of how packages or derivations are specified. For
10632 instance, the following invocations are equivalent:
10635 guix build --log-file `guix build -d guile`
10636 guix build --log-file `guix build guile`
10637 guix build --log-file guile
10638 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
10641 If a log is unavailable locally, and unless @option{--no-substitutes} is
10642 passed, the command looks for a corresponding log on one of the
10643 substitute servers (as specified with @option{--substitute-urls}).
10645 So for instance, imagine you want to see the build log of GDB on MIPS,
10646 but you are actually on an @code{x86_64} machine:
10649 $ guix build --log-file gdb -s aarch64-linux
10650 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
10653 You can freely access a huge library of build logs!
10656 @node Debugging Build Failures
10657 @subsection Debugging Build Failures
10659 @cindex build failures, debugging
10660 When defining a new package (@pxref{Defining Packages}), you will
10661 probably find yourself spending some time debugging and tweaking the
10662 build until it succeeds. To do that, you need to operate the build
10663 commands yourself in an environment as close as possible to the one the
10666 To that end, the first thing to do is to use the @option{--keep-failed}
10667 or @option{-K} option of @command{guix build}, which will keep the
10668 failed build tree in @file{/tmp} or whatever directory you specified as
10669 @env{TMPDIR} (@pxref{Invoking guix build, @option{--keep-failed}}).
10671 From there on, you can @command{cd} to the failed build tree and source
10672 the @file{environment-variables} file, which contains all the
10673 environment variable definitions that were in place when the build
10674 failed. So let's say you're debugging a build failure in package
10675 @code{foo}; a typical session would look like this:
10678 $ guix build foo -K
10679 @dots{} @i{build fails}
10680 $ cd /tmp/guix-build-foo.drv-0
10681 $ source ./environment-variables
10685 Now, you can invoke commands as if you were the daemon (almost) and
10686 troubleshoot your build process.
10688 Sometimes it happens that, for example, a package's tests pass when you
10689 run them manually but they fail when the daemon runs them. This can
10690 happen because the daemon runs builds in containers where, unlike in our
10691 environment above, network access is missing, @file{/bin/sh} does not
10692 exist, etc. (@pxref{Build Environment Setup}).
10694 In such cases, you may need to run inspect the build process from within
10695 a container similar to the one the build daemon creates:
10698 $ guix build -K foo
10700 $ cd /tmp/guix-build-foo.drv-0
10701 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
10702 [env]# source ./environment-variables
10706 Here, @command{guix environment -C} creates a container and spawns a new
10707 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
10708 strace gdb} part adds the @command{strace} and @command{gdb} commands to
10709 the container, which you may find handy while debugging. The
10710 @option{--no-grafts} option makes sure we get the exact same
10711 environment, with ungrafted packages (@pxref{Security Updates}, for more
10714 To get closer to a container like that used by the build daemon, we can
10715 remove @file{/bin/sh}:
10721 (Don't worry, this is harmless: this is all happening in the throw-away
10722 container created by @command{guix environment}.)
10724 The @command{strace} command is probably not in the search path, but we
10728 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
10731 In this way, not only you will have reproduced the environment variables
10732 the daemon uses, you will also be running the build process in a container
10733 similar to the one the daemon uses.
10736 @node Invoking guix edit
10737 @section Invoking @command{guix edit}
10739 @cindex @command{guix edit}
10740 @cindex package definition, editing
10741 So many packages, so many source files! The @command{guix edit} command
10742 facilitates the life of users and packagers by pointing their editor at
10743 the source file containing the definition of the specified packages.
10747 guix edit gcc@@4.9 vim
10751 launches the program specified in the @env{VISUAL} or in the
10752 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
10755 If you are using a Guix Git checkout (@pxref{Building from Git}), or
10756 have created your own packages on @env{GUIX_PACKAGE_PATH}
10757 (@pxref{Package Modules}), you will be able to edit the package
10758 recipes. In other cases, you will be able to examine the read-only recipes
10759 for packages currently in the store.
10761 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
10762 @option{--load-path=@var{directory}} (or in short @option{-L
10763 @var{directory}}) allows you to add @var{directory} to the front of the
10764 package module search path and so make your own packages visible.
10766 @node Invoking guix download
10767 @section Invoking @command{guix download}
10769 @cindex @command{guix download}
10770 @cindex downloading package sources
10771 When writing a package definition, developers typically need to download
10772 a source tarball, compute its SHA256 hash, and write that
10773 hash in the package definition (@pxref{Defining Packages}). The
10774 @command{guix download} tool helps with this task: it downloads a file
10775 from the given URI, adds it to the store, and prints both its file name
10776 in the store and its SHA256 hash.
10778 The fact that the downloaded file is added to the store saves bandwidth:
10779 when the developer eventually tries to build the newly defined package
10780 with @command{guix build}, the source tarball will not have to be
10781 downloaded again because it is already in the store. It is also a
10782 convenient way to temporarily stash files, which may be deleted
10783 eventually (@pxref{Invoking guix gc}).
10785 The @command{guix download} command supports the same URIs as used in
10786 package definitions. In particular, it supports @code{mirror://} URIs.
10787 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
10788 Guile bindings for GnuTLS are available in the user's environment; when
10789 they are not available, an error is raised. @xref{Guile Preparations,
10790 how to install the GnuTLS bindings for Guile,, gnutls-guile,
10791 GnuTLS-Guile}, for more information.
10793 @command{guix download} verifies HTTPS server certificates by loading
10794 the certificates of X.509 authorities from the directory pointed to by
10795 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
10796 Certificates}), unless @option{--no-check-certificate} is used.
10798 The following options are available:
10801 @item --hash=@var{algorithm}
10802 @itemx -H @var{algorithm}
10803 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
10804 hash}, for more information.
10806 @item --format=@var{fmt}
10807 @itemx -f @var{fmt}
10808 Write the hash in the format specified by @var{fmt}. For more
10809 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
10811 @item --no-check-certificate
10812 Do not validate the X.509 certificates of HTTPS servers.
10814 When using this option, you have @emph{absolutely no guarantee} that you
10815 are communicating with the authentic server responsible for the given
10816 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
10818 @item --output=@var{file}
10819 @itemx -o @var{file}
10820 Save the downloaded file to @var{file} instead of adding it to the
10824 @node Invoking guix hash
10825 @section Invoking @command{guix hash}
10827 @cindex @command{guix hash}
10828 The @command{guix hash} command computes the hash of a file.
10829 It is primarily a convenience tool for anyone contributing to the
10830 distribution: it computes the cryptographic hash of a file, which can be
10831 used in the definition of a package (@pxref{Defining Packages}).
10833 The general syntax is:
10836 guix hash @var{option} @var{file}
10839 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
10840 hash of data read from standard input. @command{guix hash} has the
10845 @item --hash=@var{algorithm}
10846 @itemx -H @var{algorithm}
10847 Compute a hash using the specified @var{algorithm}, @code{sha256} by
10850 @var{algorithm} must the name of a cryptographic hash algorithm
10851 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
10852 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
10853 Reference Manual}).
10855 @item --format=@var{fmt}
10856 @itemx -f @var{fmt}
10857 Write the hash in the format specified by @var{fmt}.
10859 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
10860 (@code{hex} and @code{hexadecimal} can be used as well).
10862 If the @option{--format} option is not specified, @command{guix hash}
10863 will output the hash in @code{nix-base32}. This representation is used
10864 in the definitions of packages.
10868 Compute the hash on @var{file} recursively.
10870 In this case, the hash is computed on an archive containing @var{file},
10871 including its children if it is a directory. Some of the metadata of
10872 @var{file} is part of the archive; for instance, when @var{file} is a
10873 regular file, the hash is different depending on whether @var{file} is
10874 executable or not. Metadata such as time stamps has no impact on the
10875 hash (@pxref{Invoking guix archive}).
10876 @c FIXME: Replace xref above with xref to an ``Archive'' section when
10879 @item --exclude-vcs
10881 When combined with @option{--recursive}, exclude version control system
10882 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
10885 As an example, here is how you would compute the hash of a Git checkout,
10886 which is useful when using the @code{git-fetch} method (@pxref{origin
10890 $ git clone http://example.org/foo.git
10896 @node Invoking guix import
10897 @section Invoking @command{guix import}
10899 @cindex importing packages
10900 @cindex package import
10901 @cindex package conversion
10902 @cindex Invoking @command{guix import}
10903 The @command{guix import} command is useful for people who would like to
10904 add a package to the distribution with as little work as
10905 possible---a legitimate demand. The command knows of a few
10906 repositories from which it can ``import'' package metadata. The result
10907 is a package definition, or a template thereof, in the format we know
10908 (@pxref{Defining Packages}).
10910 The general syntax is:
10913 guix import @var{importer} @var{options}@dots{}
10916 @var{importer} specifies the source from which to import package
10917 metadata, and @var{options} specifies a package identifier and other
10918 options specific to @var{importer}.
10920 Some of the importers rely on the ability to run the @command{gpgv} command.
10921 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
10924 Currently, the available ``importers'' are:
10928 Import metadata for the given GNU package. This provides a template
10929 for the latest version of that GNU package, including the hash of its
10930 source tarball, and its canonical synopsis and description.
10932 Additional information such as the package dependencies and its
10933 license needs to be figured out manually.
10935 For example, the following command returns a package definition for
10939 guix import gnu hello
10942 Specific command-line options are:
10945 @item --key-download=@var{policy}
10946 As for @command{guix refresh}, specify the policy to handle missing
10947 OpenPGP keys when verifying the package signature. @xref{Invoking guix
10948 refresh, @option{--key-download}}.
10953 Import metadata from the @uref{https://pypi.python.org/, Python Package
10954 Index}. Information is taken from the JSON-formatted description
10955 available at @code{pypi.python.org} and usually includes all the relevant
10956 information, including package dependencies. For maximum efficiency, it
10957 is recommended to install the @command{unzip} utility, so that the
10958 importer can unzip Python wheels and gather data from them.
10960 The command below imports metadata for the @code{itsdangerous} Python
10964 guix import pypi itsdangerous
10970 Traverse the dependency graph of the given upstream package recursively
10971 and generate package expressions for all those packages that are not yet
10977 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
10978 is taken from the JSON-formatted description available at
10979 @code{rubygems.org} and includes most relevant information, including
10980 runtime dependencies. There are some caveats, however. The metadata
10981 doesn't distinguish between synopses and descriptions, so the same string
10982 is used for both fields. Additionally, the details of non-Ruby
10983 dependencies required to build native extensions is unavailable and left
10984 as an exercise to the packager.
10986 The command below imports metadata for the @code{rails} Ruby package:
10989 guix import gem rails
10995 Traverse the dependency graph of the given upstream package recursively
10996 and generate package expressions for all those packages that are not yet
11002 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
11003 Information is taken from the JSON-formatted metadata provided through
11004 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
11005 relevant information, such as module dependencies. License information
11006 should be checked closely. If Perl is available in the store, then the
11007 @code{corelist} utility will be used to filter core modules out of the
11008 list of dependencies.
11010 The command command below imports metadata for the Acme::Boolean Perl
11014 guix import cpan Acme::Boolean
11019 @cindex Bioconductor
11020 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
11021 central repository for the @uref{https://r-project.org, GNU@tie{}R
11022 statistical and graphical environment}.
11024 Information is extracted from the @file{DESCRIPTION} file of the package.
11026 The command command below imports metadata for the Cairo R package:
11029 guix import cran Cairo
11032 When @option{--recursive} is added, the importer will traverse the
11033 dependency graph of the given upstream package recursively and generate
11034 package expressions for all those packages that are not yet in Guix.
11036 When @option{--style=specification} is added, the importer will generate
11037 package definitions whose inputs are package specifications instead of
11038 references to package variables. This is useful when generated package
11039 definitions are to be appended to existing user modules, as the list of
11040 used package modules need not be changed. The default is
11041 @option{--style=variable}.
11043 When @option{--archive=bioconductor} is added, metadata is imported from
11044 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
11045 packages for the analysis and comprehension of high-throughput
11046 genomic data in bioinformatics.
11048 Information is extracted from the @file{DESCRIPTION} file contained in the
11051 The command below imports metadata for the GenomicRanges R package:
11054 guix import cran --archive=bioconductor GenomicRanges
11057 Finally, you can also import R packages that have not yet been published on
11058 CRAN or Bioconductor as long as they are in a git repository. Use
11059 @option{--archive=git} followed by the URL of the git repository:
11062 guix import cran --archive=git https://github.com/immunogenomics/harmony
11068 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
11069 comprehensive TeX archive network for TeX packages that are part of the
11070 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
11072 Information about the package is obtained through the XML API provided
11073 by CTAN, while the source code is downloaded from the SVN repository of
11074 the Tex Live project. This is done because the CTAN does not keep
11075 versioned archives.
11077 The command command below imports metadata for the @code{fontspec}
11081 guix import texlive fontspec
11084 When @option{--archive=@var{directory}} is added, the source code is
11085 downloaded not from the @file{latex} sub-directory of the
11086 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
11087 the specified sibling @var{directory} under the same root.
11089 The command below imports metadata for the @code{ifxetex} package from
11090 CTAN while fetching the sources from the directory
11091 @file{texmf/source/generic}:
11094 guix import texlive --archive=generic ifxetex
11098 @cindex JSON, import
11099 Import package metadata from a local JSON file. Consider the following
11100 example package definition in JSON format:
11106 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
11107 "build-system": "gnu",
11108 "home-page": "https://www.gnu.org/software/hello/",
11109 "synopsis": "Hello, GNU world: An example GNU package",
11110 "description": "GNU Hello prints a greeting.",
11111 "license": "GPL-3.0+",
11112 "native-inputs": ["gettext"]
11116 The field names are the same as for the @code{<package>} record
11117 (@xref{Defining Packages}). References to other packages are provided
11118 as JSON lists of quoted package specification strings such as
11119 @code{guile} or @code{guile@@2.0}.
11121 The importer also supports a more explicit source definition using the
11122 common fields for @code{<origin>} records:
11128 "method": "url-fetch",
11129 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
11131 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
11138 The command below reads metadata from the JSON file @code{hello.json}
11139 and outputs a package expression:
11142 guix import json hello.json
11146 Import metadata from a local copy of the source of the
11147 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
11148 relies on the @command{nix-instantiate} command of
11149 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
11150 typically written in a mixture of Nix-language and Bash code. This
11151 command only imports the high-level package structure that is written in
11152 the Nix language. It normally includes all the basic fields of a
11153 package definition.
11155 When importing a GNU package, the synopsis and descriptions are replaced
11156 by their canonical upstream variant.
11158 Usually, you will first need to do:
11161 export NIX_REMOTE=daemon
11165 so that @command{nix-instantiate} does not try to open the Nix database.
11167 As an example, the command below imports the package definition of
11168 LibreOffice (more precisely, it imports the definition of the package
11169 bound to the @code{libreoffice} top-level attribute):
11172 guix import nix ~/path/to/nixpkgs libreoffice
11177 Import metadata from the Haskell community's central package archive
11178 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
11179 Cabal files and includes all the relevant information, including package
11182 Specific command-line options are:
11187 Read a Cabal file from standard input.
11188 @item --no-test-dependencies
11190 Do not include dependencies required only by the test suites.
11191 @item --cabal-environment=@var{alist}
11192 @itemx -e @var{alist}
11193 @var{alist} is a Scheme alist defining the environment in which the
11194 Cabal conditionals are evaluated. The accepted keys are: @code{os},
11195 @code{arch}, @code{impl} and a string representing the name of a flag.
11196 The value associated with a flag has to be either the symbol
11197 @code{true} or @code{false}. The value associated with other keys
11198 has to conform to the Cabal file format definition. The default value
11199 associated with the keys @code{os}, @code{arch} and @code{impl} is
11200 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
11203 Traverse the dependency graph of the given upstream package recursively
11204 and generate package expressions for all those packages that are not yet
11208 The command below imports metadata for the latest version of the
11209 HTTP Haskell package without including test dependencies and
11210 specifying the value of the flag @samp{network-uri} as @code{false}:
11213 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
11216 A specific package version may optionally be specified by following the
11217 package name by an at-sign and a version number as in the following example:
11220 guix import hackage mtl@@2.1.3.1
11225 The @code{stackage} importer is a wrapper around the @code{hackage} one.
11226 It takes a package name, looks up the package version included in a
11227 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
11228 release and uses the @code{hackage} importer to retrieve its metadata.
11229 Note that it is up to you to select an LTS release compatible with the
11230 GHC compiler used by Guix.
11232 Specific command-line options are:
11235 @item --no-test-dependencies
11237 Do not include dependencies required only by the test suites.
11238 @item --lts-version=@var{version}
11239 @itemx -l @var{version}
11240 @var{version} is the desired LTS release version. If omitted the latest
11244 Traverse the dependency graph of the given upstream package recursively
11245 and generate package expressions for all those packages that are not yet
11249 The command below imports metadata for the HTTP Haskell package
11250 included in the LTS Stackage release version 7.18:
11253 guix import stackage --lts-version=7.18 HTTP
11258 Import metadata from an Emacs Lisp Package Archive (ELPA) package
11259 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
11261 Specific command-line options are:
11264 @item --archive=@var{repo}
11265 @itemx -a @var{repo}
11266 @var{repo} identifies the archive repository from which to retrieve the
11267 information. Currently the supported repositories and their identifiers
11271 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
11272 identifier. This is the default.
11274 Packages from @code{elpa.gnu.org} are signed with one of the keys
11275 contained in the GnuPG keyring at
11276 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
11277 @code{emacs} package (@pxref{Package Installation, ELPA package
11278 signatures,, emacs, The GNU Emacs Manual}).
11281 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
11282 @code{melpa-stable} identifier.
11285 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
11291 Traverse the dependency graph of the given upstream package recursively
11292 and generate package expressions for all those packages that are not yet
11298 Import metadata from the crates.io Rust package repository
11299 @uref{https://crates.io, crates.io}, as in this example:
11302 guix import crate blake2-rfc
11305 The crate importer also allows you to specify a version string:
11308 guix import crate constant-time-eq@@0.1.0
11311 Additional options include:
11316 Traverse the dependency graph of the given upstream package recursively
11317 and generate package expressions for all those packages that are not yet
11324 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
11325 repository used by the OCaml community.
11327 Additional options include:
11332 Traverse the dependency graph of the given upstream package recursively
11333 and generate package expressions for all those packages that are not yet
11336 Select the given repository (a repository name). Possible values include:
11338 @item @code{opam}, the default opam repository,
11339 @item @code{coq} or @code{coq-released}, the stable repository for coq packages,
11340 @item @code{coq-core-dev}, the repository that contains development versions of coq,
11341 @item @code{coq-extra-dev}, the repository that contains development versions
11347 The structure of the @command{guix import} code is modular. It would be
11348 useful to have more importers for other package formats, and your help
11349 is welcome here (@pxref{Contributing}).
11351 @node Invoking guix refresh
11352 @section Invoking @command{guix refresh}
11354 @cindex @command {guix refresh}
11355 The primary audience of the @command{guix refresh} command is developers
11356 of the GNU software distribution. By default, it reports any packages
11357 provided by the distribution that are outdated compared to the latest
11358 upstream version, like this:
11362 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
11363 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
11366 Alternatively, one can specify packages to consider, in which case a
11367 warning is emitted for packages that lack an updater:
11370 $ guix refresh coreutils guile guile-ssh
11371 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
11372 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
11375 @command{guix refresh} browses the upstream repository of each package and determines
11376 the highest version number of the releases therein. The command
11377 knows how to update specific types of packages: GNU packages, ELPA
11378 packages, etc.---see the documentation for @option{--type} below. There
11379 are many packages, though, for which it lacks a method to determine
11380 whether a new upstream release is available. However, the mechanism is
11381 extensible, so feel free to get in touch with us to add a new method!
11386 Consider the packages specified, and all the packages upon which they depend.
11389 $ guix refresh --recursive coreutils
11390 gnu/packages/acl.scm:35:2: warning: no updater for acl
11391 gnu/packages/m4.scm:30:12: info: 1.4.18 is already the latest version of m4
11392 gnu/packages/xml.scm:68:2: warning: no updater for expat
11393 gnu/packages/multiprecision.scm:40:12: info: 6.1.2 is already the latest version of gmp
11399 Sometimes the upstream name differs from the package name used in Guix,
11400 and @command{guix refresh} needs a little help. Most updaters honor the
11401 @code{upstream-name} property in package definitions, which can be used
11405 (define-public network-manager
11407 (name "network-manager")
11409 (properties '((upstream-name . "NetworkManager")))))
11412 When passed @option{--update}, it modifies distribution source files to
11413 update the version numbers and source tarball hashes of those package
11414 recipes (@pxref{Defining Packages}). This is achieved by downloading
11415 each package's latest source tarball and its associated OpenPGP
11416 signature, authenticating the downloaded tarball against its signature
11417 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
11418 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
11421 key used to sign the tarball is missing from the user's keyring, an
11422 attempt is made to automatically retrieve it from a public key server;
11423 when this is successful, the key is added to the user's keyring; otherwise,
11424 @command{guix refresh} reports an error.
11426 The following options are supported:
11430 @item --expression=@var{expr}
11431 @itemx -e @var{expr}
11432 Consider the package @var{expr} evaluates to.
11434 This is useful to precisely refer to a package, as in this example:
11437 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
11440 This command lists the dependents of the ``final'' libc (essentially all
11445 Update distribution source files (package recipes) in place. This is
11446 usually run from a checkout of the Guix source tree (@pxref{Running
11447 Guix Before It Is Installed}):
11450 $ ./pre-inst-env guix refresh -s non-core -u
11453 @xref{Defining Packages}, for more information on package definitions.
11455 @item --select=[@var{subset}]
11456 @itemx -s @var{subset}
11457 Select all the packages in @var{subset}, one of @code{core} or
11460 The @code{core} subset refers to all the packages at the core of the
11461 distribution---i.e., packages that are used to build ``everything
11462 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
11463 changing one of these packages in the distribution entails a rebuild of
11464 all the others. Thus, such updates are an inconvenience to users in
11465 terms of build time or bandwidth used to achieve the upgrade.
11467 The @code{non-core} subset refers to the remaining packages. It is
11468 typically useful in cases where an update of the core packages would be
11471 @item --manifest=@var{file}
11472 @itemx -m @var{file}
11473 Select all the packages from the manifest in @var{file}. This is useful to
11474 check if any packages of the user manifest can be updated.
11476 @item --type=@var{updater}
11477 @itemx -t @var{updater}
11478 Select only packages handled by @var{updater} (may be a comma-separated
11479 list of updaters). Currently, @var{updater} may be one of:
11483 the updater for GNU packages;
11485 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
11487 the updater for GNOME packages;
11489 the updater for KDE packages;
11491 the updater for X.org packages;
11493 the updater for packages hosted on kernel.org;
11495 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
11497 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
11499 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
11501 the updater for @uref{https://www.cpan.org/, CPAN} packages;
11503 the updater for @uref{https://pypi.python.org, PyPI} packages.
11505 the updater for @uref{https://rubygems.org, RubyGems} packages.
11507 the updater for @uref{https://github.com, GitHub} packages.
11509 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
11511 the updater for @uref{https://www.stackage.org, Stackage} packages.
11513 the updater for @uref{https://crates.io, Crates} packages.
11515 the updater for @uref{https://launchpad.net, Launchpad} packages.
11518 For instance, the following command only checks for updates of Emacs
11519 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
11522 $ guix refresh --type=elpa,cran
11523 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
11524 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
11529 In addition, @command{guix refresh} can be passed one or more package
11530 names, as in this example:
11533 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
11537 The command above specifically updates the @code{emacs} and
11538 @code{idutils} packages. The @option{--select} option would have no
11539 effect in this case.
11541 When considering whether to upgrade a package, it is sometimes
11542 convenient to know which packages would be affected by the upgrade and
11543 should be checked for compatibility. For this the following option may
11544 be used when passing @command{guix refresh} one or more package names:
11548 @item --list-updaters
11550 List available updaters and exit (see @option{--type} above).
11552 For each updater, display the fraction of packages it covers; at the
11553 end, display the fraction of packages covered by all these updaters.
11555 @item --list-dependent
11557 List top-level dependent packages that would need to be rebuilt as a
11558 result of upgrading one or more packages.
11560 @xref{Invoking guix graph, the @code{reverse-package} type of
11561 @command{guix graph}}, for information on how to visualize the list of
11562 dependents of a package.
11566 Be aware that the @option{--list-dependent} option only
11567 @emph{approximates} the rebuilds that would be required as a result of
11568 an upgrade. More rebuilds might be required under some circumstances.
11571 $ guix refresh --list-dependent flex
11572 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
11573 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
11576 The command above lists a set of packages that could be built to check
11577 for compatibility with an upgraded @code{flex} package.
11581 @item --list-transitive
11582 List all the packages which one or more packages depend upon.
11585 $ guix refresh --list-transitive flex
11586 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
11587 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{}
11592 The command above lists a set of packages which, when changed, would cause
11593 @code{flex} to be rebuilt.
11595 The following options can be used to customize GnuPG operation:
11599 @item --gpg=@var{command}
11600 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
11601 for in @code{$PATH}.
11603 @item --keyring=@var{file}
11604 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
11605 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
11606 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
11607 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
11608 information on a tool to manipulate keybox files).
11610 When this option is omitted, @command{guix refresh} uses
11611 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
11612 signing keys. OpenPGP signatures are checked against keys from this keyring;
11613 missing keys are downloaded to this keyring as well (see
11614 @option{--key-download} below).
11616 You can export keys from your default GPG keyring into a keybox file using
11617 commands like this one:
11620 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
11623 Likewise, you can fetch keys to a specific keybox file like this:
11626 gpg --no-default-keyring --keyring mykeyring.kbx \
11627 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
11630 @ref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
11631 Privacy Guard}, for more information on GPG's @option{--keyring} option.
11633 @item --key-download=@var{policy}
11634 Handle missing OpenPGP keys according to @var{policy}, which may be one
11639 Always download missing OpenPGP keys from the key server, and add them
11640 to the user's GnuPG keyring.
11643 Never try to download missing OpenPGP keys. Instead just bail out.
11646 When a package signed with an unknown OpenPGP key is encountered, ask
11647 the user whether to download it or not. This is the default behavior.
11650 @item --key-server=@var{host}
11651 Use @var{host} as the OpenPGP key server when importing a public key.
11653 @item --load-path=@var{directory}
11654 Add @var{directory} to the front of the package module search path
11655 (@pxref{Package Modules}).
11657 This allows users to define their own packages and make them visible to
11658 the command-line tools.
11662 The @code{github} updater uses the
11663 @uref{https://developer.github.com/v3/, GitHub API} to query for new
11664 releases. When used repeatedly e.g.@: when refreshing all packages,
11665 GitHub will eventually refuse to answer any further API requests. By
11666 default 60 API requests per hour are allowed, and a full refresh on all
11667 GitHub packages in Guix requires more than this. Authentication with
11668 GitHub through the use of an API token alleviates these limits. To use
11669 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
11670 token procured from @uref{https://github.com/settings/tokens} or
11674 @node Invoking guix lint
11675 @section Invoking @command{guix lint}
11677 @cindex @command{guix lint}
11678 @cindex package, checking for errors
11679 The @command{guix lint} command is meant to help package developers avoid
11680 common errors and use a consistent style. It runs a number of checks on
11681 a given set of packages in order to find common mistakes in their
11682 definitions. Available @dfn{checkers} include (see
11683 @option{--list-checkers} for a complete list):
11688 Validate certain typographical and stylistic rules about package
11689 descriptions and synopses.
11691 @item inputs-should-be-native
11692 Identify inputs that should most likely be native inputs.
11698 @itemx source-file-name
11699 Probe @code{home-page} and @code{source} URLs and report those that are
11700 invalid. Suggest a @code{mirror://} URL when applicable. If the
11701 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
11702 URL. Check that the source file name is meaningful, e.g.@: is not just a
11703 version number or ``git-checkout'', without a declared @code{file-name}
11704 (@pxref{origin Reference}).
11706 @item source-unstable-tarball
11707 Parse the @code{source} URL to determine if a tarball from GitHub is
11708 autogenerated or if it is a release tarball. Unfortunately GitHub's
11709 autogenerated tarballs are sometimes regenerated.
11712 Check that the derivation of the given packages can be successfully
11713 computed for all the supported systems (@pxref{Derivations}).
11715 @item profile-collisions
11716 Check whether installing the given packages in a profile would lead to
11717 collisions. Collisions occur when several packages with the same name
11718 but a different version or a different store file name are propagated.
11719 @xref{package Reference, @code{propagated-inputs}}, for more information
11720 on propagated inputs.
11723 @cindex Software Heritage, source code archive
11724 @cindex archival of source code, Software Heritage
11725 Checks whether the package's source code is archived at
11726 @uref{https://www.softwareheritage.org, Software Heritage}.
11728 When the source code that is not archived comes from a version-control system
11729 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
11730 ``save'' request so that it eventually archives it. This ensures that the
11731 source will remain available in the long term, and that Guix can fall back to
11732 Software Heritage should the source code disappear from its original host.
11733 The status of recent ``save'' requests can be
11734 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
11736 When source code is a tarball obtained with @code{url-fetch}, simply print a
11737 message when it is not archived. As of this writing, Software Heritage does
11738 not allow requests to save arbitrary tarballs; we are working on ways to
11739 ensure that non-VCS source code is also archived.
11742 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
11743 request rate per IP address}. When the limit is reached, @command{guix lint}
11744 prints a message and the @code{archival} checker stops doing anything until
11745 that limit has been reset.
11748 @cindex security vulnerabilities
11749 @cindex CVE, Common Vulnerabilities and Exposures
11750 Report known vulnerabilities found in the Common Vulnerabilities and
11751 Exposures (CVE) databases of the current and past year
11752 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
11755 To view information about a particular vulnerability, visit pages such as:
11759 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
11761 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
11765 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
11766 @code{CVE-2015-7554}.
11768 Package developers can specify in package recipes the
11769 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
11770 name and version of the package when they differ from the name or version
11771 that Guix uses, as in this example:
11777 ;; CPE calls this package "grub2".
11778 (properties '((cpe-name . "grub2")
11779 (cpe-version . "2.3"))))
11782 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
11783 Some entries in the CVE database do not specify which version of a
11784 package they apply to, and would thus ``stick around'' forever. Package
11785 developers who found CVE alerts and verified they can be ignored can
11786 declare them as in this example:
11792 ;; These CVEs no longer apply and can be safely ignored.
11793 (properties `((lint-hidden-cve . ("CVE-2011-0433"
11796 "CVE-2011-5244")))))
11800 Warn about obvious source code formatting issues: trailing white space,
11801 use of tabulations, etc.
11804 The general syntax is:
11807 guix lint @var{options} @var{package}@dots{}
11810 If no package is given on the command line, then all packages are checked.
11811 The @var{options} may be zero or more of the following:
11814 @item --list-checkers
11816 List and describe all the available checkers that will be run on packages
11821 Only enable the checkers specified in a comma-separated list using the
11822 names returned by @option{--list-checkers}.
11826 Only disable the checkers specified in a comma-separated list using the
11827 names returned by @option{--list-checkers}.
11831 Only enable the checkers that do not depend on Internet access.
11833 @item --load-path=@var{directory}
11834 @itemx -L @var{directory}
11835 Add @var{directory} to the front of the package module search path
11836 (@pxref{Package Modules}).
11838 This allows users to define their own packages and make them visible to
11839 the command-line tools.
11843 @node Invoking guix size
11844 @section Invoking @command{guix size}
11847 @cindex package size
11849 @cindex @command{guix size}
11850 The @command{guix size} command helps package developers profile the
11851 disk usage of packages. It is easy to overlook the impact of an
11852 additional dependency added to a package, or the impact of using a
11853 single output for a package that could easily be split (@pxref{Packages
11854 with Multiple Outputs}). Such are the typical issues that
11855 @command{guix size} can highlight.
11857 The command can be passed one or more package specifications
11858 such as @code{gcc@@4.8}
11859 or @code{guile:debug}, or a file name in the store. Consider this
11863 $ guix size coreutils
11864 store item total self
11865 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
11866 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
11867 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
11868 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
11869 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
11870 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
11871 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
11872 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
11877 The store items listed here constitute the @dfn{transitive closure} of
11878 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
11879 would be returned by:
11882 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
11885 Here the output shows three columns next to store items. The first column,
11886 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
11887 the store item---that is, its own size plus the size of all its
11888 dependencies. The next column, labeled ``self'', shows the size of the
11889 item itself. The last column shows the ratio of the size of the item
11890 itself to the space occupied by all the items listed here.
11892 In this example, we see that the closure of Coreutils weighs in at
11893 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
11894 libraries. (That libc and GCC's libraries represent a large fraction of
11895 the closure is not a problem @i{per se} because they are always available
11896 on the system anyway.)
11898 Since the command also accepts store file names, assessing the size of
11899 a build result is straightforward:
11902 guix size $(guix system build config.scm)
11905 When the package(s) passed to @command{guix size} are available in the
11906 store@footnote{More precisely, @command{guix size} looks for the
11907 @emph{ungrafted} variant of the given package(s), as returned by
11908 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
11909 for information on grafts.}, @command{guix size} queries the daemon to determine its
11910 dependencies, and measures its size in the store, similar to @command{du
11911 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
11914 When the given packages are @emph{not} in the store, @command{guix size}
11915 reports information based on the available substitutes
11916 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
11917 store items that are not even on disk, only available remotely.
11919 You can also specify several package names:
11922 $ guix size coreutils grep sed bash
11923 store item total self
11924 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
11925 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
11926 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
11927 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
11933 In this example we see that the combination of the four packages takes
11934 102.3@tie{}MiB in total, which is much less than the sum of each closure
11935 since they have a lot of dependencies in common.
11937 When looking at the profile returned by @command{guix size}, you may
11938 find yourself wondering why a given package shows up in the profile at
11939 all. To understand it, you can use @command{guix graph --path -t
11940 references} to display the shortest path between the two packages
11941 (@pxref{Invoking guix graph}).
11943 The available options are:
11947 @item --substitute-urls=@var{urls}
11948 Use substitute information from @var{urls}.
11949 @xref{client-substitute-urls, the same option for @code{guix build}}.
11951 @item --sort=@var{key}
11952 Sort lines according to @var{key}, one of the following options:
11956 the size of each item (the default);
11958 the total size of the item's closure.
11961 @item --map-file=@var{file}
11962 Write a graphical map of disk usage in PNG format to @var{file}.
11964 For the example above, the map looks like this:
11966 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
11967 produced by @command{guix size}}
11969 This option requires that
11970 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
11971 installed and visible in Guile's module search path. When that is not
11972 the case, @command{guix size} fails as it tries to load it.
11974 @item --system=@var{system}
11975 @itemx -s @var{system}
11976 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
11978 @item --load-path=@var{directory}
11979 @itemx -L @var{directory}
11980 Add @var{directory} to the front of the package module search path
11981 (@pxref{Package Modules}).
11983 This allows users to define their own packages and make them visible to
11984 the command-line tools.
11987 @node Invoking guix graph
11988 @section Invoking @command{guix graph}
11991 @cindex @command{guix graph}
11992 @cindex package dependencies
11993 Packages and their dependencies form a @dfn{graph}, specifically a
11994 directed acyclic graph (DAG). It can quickly become difficult to have a
11995 mental model of the package DAG, so the @command{guix graph} command
11996 provides a visual representation of the DAG. By default,
11997 @command{guix graph} emits a DAG representation in the input format of
11998 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
11999 directly to the @command{dot} command of Graphviz. It can also emit an
12000 HTML page with embedded JavaScript code to display a ``chord diagram''
12001 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
12002 emit Cypher queries to construct a graph in a graph database supporting
12003 the @uref{https://www.opencypher.org/, openCypher} query language. With
12004 @option{--path}, it simply displays the shortest path between two
12005 packages. The general syntax is:
12008 guix graph @var{options} @var{package}@dots{}
12011 For example, the following command generates a PDF file representing the
12012 package DAG for the GNU@tie{}Core Utilities, showing its build-time
12016 guix graph coreutils | dot -Tpdf > dag.pdf
12019 The output looks like this:
12021 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
12023 Nice little graph, no?
12025 You may find it more pleasant to navigate the graph interactively with
12026 @command{xdot} (from the @code{xdot} package):
12029 guix graph coreutils | xdot -
12032 But there is more than one graph! The one above is concise: it is the
12033 graph of package objects, omitting implicit inputs such as GCC, libc,
12034 grep, etc. It is often useful to have such a concise graph, but
12035 sometimes one may want to see more details. @command{guix graph} supports
12036 several types of graphs, allowing you to choose the level of detail:
12040 This is the default type used in the example above. It shows the DAG of
12041 package objects, excluding implicit dependencies. It is concise, but
12042 filters out many details.
12044 @item reverse-package
12045 This shows the @emph{reverse} DAG of packages. For example:
12048 guix graph --type=reverse-package ocaml
12051 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
12052 you are also interested in cases where OCaml is an implicit dependency, see
12053 @code{reverse-bag} below).
12055 Note that for core packages this can yield huge graphs. If all you want
12056 is to know the number of packages that depend on a given package, use
12057 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
12058 @option{--list-dependent}}).
12061 This is the package DAG, @emph{including} implicit inputs.
12063 For instance, the following command:
12066 guix graph --type=bag-emerged coreutils
12069 ...@: yields this bigger graph:
12071 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
12073 At the bottom of the graph, we see all the implicit inputs of
12074 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
12076 Now, note that the dependencies of these implicit inputs---that is, the
12077 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
12078 here, for conciseness.
12081 Similar to @code{bag-emerged}, but this time including all the bootstrap
12084 @item bag-with-origins
12085 Similar to @code{bag}, but also showing origins and their dependencies.
12088 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
12089 it also takes implicit dependencies into account. For example:
12092 guix graph -t reverse-bag dune
12096 ...@: yields the graph of all packages that depend on Dune, directly or
12097 indirectly. Since Dune is an @emph{implicit} dependency of many packages
12098 @i{via} @code{dune-build-system}, this shows a large number of packages,
12099 whereas @code{reverse-package} would show very few if any.
12102 This is the most detailed representation: It shows the DAG of
12103 derivations (@pxref{Derivations}) and plain store items. Compared to
12104 the above representation, many additional nodes are visible, including
12105 build scripts, patches, Guile modules, etc.
12107 For this type of graph, it is also possible to pass a @file{.drv} file
12108 name instead of a package name, as in:
12111 guix graph -t derivation `guix system build -d my-config.scm`
12115 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
12116 For example, the following command shows the graph for the package
12117 module that defines the @code{guile} package:
12120 guix graph -t module guile | xdot -
12124 All the types above correspond to @emph{build-time dependencies}. The
12125 following graph type represents the @emph{run-time dependencies}:
12129 This is the graph of @dfn{references} of a package output, as returned
12130 by @command{guix gc --references} (@pxref{Invoking guix gc}).
12132 If the given package output is not available in the store, @command{guix
12133 graph} attempts to obtain dependency information from substitutes.
12135 Here you can also pass a store file name instead of a package name. For
12136 example, the command below produces the reference graph of your profile
12137 (which can be big!):
12140 guix graph -t references `readlink -f ~/.guix-profile`
12144 This is the graph of the @dfn{referrers} of a store item, as returned by
12145 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
12147 This relies exclusively on local information from your store. For
12148 instance, let us suppose that the current Inkscape is available in 10
12149 profiles on your machine; @command{guix graph -t referrers inkscape}
12150 will show a graph rooted at Inkscape and with those 10 profiles linked
12153 It can help determine what is preventing a store item from being garbage
12158 @cindex shortest path, between packages
12159 Often, the graph of the package you are interested in does not fit on
12160 your screen, and anyway all you want to know is @emph{why} that package
12161 actually depends on some seemingly unrelated package. The
12162 @option{--path} option instructs @command{guix graph} to display the
12163 shortest path between two packages (or derivations, or store items,
12167 $ guix graph --path emacs libunistring
12170 libunistring@@0.9.10
12171 $ guix graph --path -t derivation emacs libunistring
12172 /gnu/store/@dots{}-emacs-26.3.drv
12173 /gnu/store/@dots{}-mailutils-3.9.drv
12174 /gnu/store/@dots{}-libunistring-0.9.10.drv
12175 $ guix graph --path -t references emacs libunistring
12176 /gnu/store/@dots{}-emacs-26.3
12177 /gnu/store/@dots{}-libidn2-2.2.0
12178 /gnu/store/@dots{}-libunistring-0.9.10
12181 The available options are the following:
12184 @item --type=@var{type}
12185 @itemx -t @var{type}
12186 Produce a graph output of @var{type}, where @var{type} must be one of
12187 the values listed above.
12190 List the supported graph types.
12192 @item --backend=@var{backend}
12193 @itemx -b @var{backend}
12194 Produce a graph using the selected @var{backend}.
12196 @item --list-backends
12197 List the supported graph backends.
12199 Currently, the available backends are Graphviz and d3.js.
12202 Display the shortest path between two nodes of the type specified by
12203 @option{--type}. The example below shows the shortest path between
12204 @code{libreoffice} and @code{llvm} according to the references of
12205 @code{libreoffice}:
12208 $ guix graph --path -t references libreoffice llvm
12209 /gnu/store/@dots{}-libreoffice-6.4.2.2
12210 /gnu/store/@dots{}-libepoxy-1.5.4
12211 /gnu/store/@dots{}-mesa-19.3.4
12212 /gnu/store/@dots{}-llvm-9.0.1
12215 @item --expression=@var{expr}
12216 @itemx -e @var{expr}
12217 Consider the package @var{expr} evaluates to.
12219 This is useful to precisely refer to a package, as in this example:
12222 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
12225 @item --system=@var{system}
12226 @itemx -s @var{system}
12227 Display the graph for @var{system}---e.g., @code{i686-linux}.
12229 The package dependency graph is largely architecture-independent, but there
12230 are some architecture-dependent bits that this option allows you to visualize.
12232 @item --load-path=@var{directory}
12233 @itemx -L @var{directory}
12234 Add @var{directory} to the front of the package module search path
12235 (@pxref{Package Modules}).
12237 This allows users to define their own packages and make them visible to
12238 the command-line tools.
12241 On top of that, @command{guix graph} supports all the usual package
12242 transformation options (@pxref{Package Transformation Options}). This
12243 makes it easy to view the effect of a graph-rewriting transformation
12244 such as @option{--with-input}. For example, the command below outputs
12245 the graph of @code{git} once @code{openssl} has been replaced by
12246 @code{libressl} everywhere in the graph:
12249 guix graph git --with-input=openssl=libressl
12252 So many possibilities, so much fun!
12254 @node Invoking guix publish
12255 @section Invoking @command{guix publish}
12257 @cindex @command{guix publish}
12258 The purpose of @command{guix publish} is to enable users to easily share
12259 their store with others, who can then use it as a substitute server
12260 (@pxref{Substitutes}).
12262 When @command{guix publish} runs, it spawns an HTTP server which allows
12263 anyone with network access to obtain substitutes from it. This means
12264 that any machine running Guix can also act as if it were a build farm,
12265 since the HTTP interface is compatible with Cuirass, the software behind
12266 the @code{@value{SUBSTITUTE-SERVER}} build farm.
12268 For security, each substitute is signed, allowing recipients to check
12269 their authenticity and integrity (@pxref{Substitutes}). Because
12270 @command{guix publish} uses the signing key of the system, which is only
12271 readable by the system administrator, it must be started as root; the
12272 @option{--user} option makes it drop root privileges early on.
12274 The signing key pair must be generated before @command{guix publish} is
12275 launched, using @command{guix archive --generate-key} (@pxref{Invoking
12278 When the @option{--advertise} option is passed, the server advertises
12279 its availability on the local network using multicast DNS (mDNS) and DNS
12280 service discovery (DNS-SD), currently @i{via} Guile-Avahi (@pxref{Top,,,
12281 guile-avahi, Using Avahi in Guile Scheme Programs}).
12283 The general syntax is:
12286 guix publish @var{options}@dots{}
12289 Running @command{guix publish} without any additional arguments will
12290 spawn an HTTP server on port 8080:
12296 Once a publishing server has been authorized, the daemon may download
12297 substitutes from it. @xref{Getting Substitutes from Other Servers}.
12299 By default, @command{guix publish} compresses archives on the fly as it
12300 serves them. This ``on-the-fly'' mode is convenient in that it requires
12301 no setup and is immediately available. However, when serving lots of
12302 clients, we recommend using the @option{--cache} option, which enables
12303 caching of the archives before they are sent to clients---see below for
12304 details. The @command{guix weather} command provides a handy way to
12305 check what a server provides (@pxref{Invoking guix weather}).
12307 As a bonus, @command{guix publish} also serves as a content-addressed
12308 mirror for source files referenced in @code{origin} records
12309 (@pxref{origin Reference}). For instance, assuming @command{guix
12310 publish} is running on @code{example.org}, the following URL returns the
12311 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
12312 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
12315 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
12318 Obviously, these URLs only work for files that are in the store; in
12319 other cases, they return 404 (``Not Found'').
12321 @cindex build logs, publication
12322 Build logs are available from @code{/log} URLs like:
12325 http://example.org/log/gwspk@dots{}-guile-2.2.3
12329 When @command{guix-daemon} is configured to save compressed build logs,
12330 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
12331 URLs return the compressed log as-is, with an appropriate
12332 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
12333 running @command{guix-daemon} with @option{--log-compression=gzip} since
12334 Web browsers can automatically decompress it, which is not the case with
12337 The following options are available:
12340 @item --port=@var{port}
12341 @itemx -p @var{port}
12342 Listen for HTTP requests on @var{port}.
12344 @item --listen=@var{host}
12345 Listen on the network interface for @var{host}. The default is to
12346 accept connections from any interface.
12348 @item --user=@var{user}
12349 @itemx -u @var{user}
12350 Change privileges to @var{user} as soon as possible---i.e., once the
12351 server socket is open and the signing key has been read.
12353 @item --compression[=@var{method}[:@var{level}]]
12354 @itemx -C [@var{method}[:@var{level}]]
12355 Compress data using the given @var{method} and @var{level}. @var{method} is
12356 one of @code{lzip}, @code{zstd}, and @code{gzip}; when @var{method} is
12357 omitted, @code{gzip} is used.
12359 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
12360 to different compression levels: 1 is the fastest, and 9 is the best
12361 (CPU-intensive). The default is 3.
12363 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a
12364 small increase in CPU usage; see
12365 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip
12366 Web page}. However, @code{lzip} achieves low decompression throughput
12367 (on the order of 50@tie{}MiB/s on modern hardware), which can be a
12368 bottleneck for someone who downloads over a fast network connection.
12370 The compression ratio of @code{zstd} is between that of @code{lzip} and
12371 that of @code{gzip}; its main advantage is a
12372 @uref{https://facebook.github.io/zstd/,high decompression speed}.
12374 Unless @option{--cache} is used, compression occurs on the fly and
12375 the compressed streams are not
12376 cached. Thus, to reduce load on the machine that runs @command{guix
12377 publish}, it may be a good idea to choose a low compression level, to
12378 run @command{guix publish} behind a caching proxy, or to use
12379 @option{--cache}. Using @option{--cache} has the advantage that it
12380 allows @command{guix publish} to add @code{Content-Length} HTTP header
12383 This option can be repeated, in which case every substitute gets compressed
12384 using all the selected methods, and all of them are advertised. This is
12385 useful when users may not support all the compression methods: they can select
12386 the one they support.
12388 @item --cache=@var{directory}
12389 @itemx -c @var{directory}
12390 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
12391 and only serve archives that are in cache.
12393 When this option is omitted, archives and meta-data are created
12394 on-the-fly. This can reduce the available bandwidth, especially when
12395 compression is enabled, since this may become CPU-bound. Another
12396 drawback of the default mode is that the length of archives is not known
12397 in advance, so @command{guix publish} does not add a
12398 @code{Content-Length} HTTP header to its responses, which in turn
12399 prevents clients from knowing the amount of data being downloaded.
12401 Conversely, when @option{--cache} is used, the first request for a store
12402 item (@i{via} a @code{.narinfo} URL) triggers a
12403 background process to @dfn{bake} the archive---computing its
12404 @code{.narinfo} and compressing the archive, if needed. Once the
12405 archive is cached in @var{directory}, subsequent requests succeed and
12406 are served directly from the cache, which guarantees that clients get
12407 the best possible bandwidth.
12409 That first @code{.narinfo} request nonetheless returns 200, provided the
12410 requested store item is ``small enough'', below the cache bypass
12411 threshold---see @option{--cache-bypass-threshold} below. That way,
12412 clients do not have to wait until the archive is baked. For larger
12413 store items, the first @code{.narinfo} request returns 404, meaning that
12414 clients have to wait until the archive is baked.
12416 The ``baking'' process is performed by worker threads. By default, one
12417 thread per CPU core is created, but this can be customized. See
12418 @option{--workers} below.
12420 When @option{--ttl} is used, cached entries are automatically deleted
12421 when they have expired.
12423 @item --workers=@var{N}
12424 When @option{--cache} is used, request the allocation of @var{N} worker
12425 threads to ``bake'' archives.
12427 @item --ttl=@var{ttl}
12428 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
12429 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
12430 days, @code{1m} means 1 month, and so on.
12432 This allows the user's Guix to keep substitute information in cache for
12433 @var{ttl}. However, note that @code{guix publish} does not itself
12434 guarantee that the store items it provides will indeed remain available
12435 for as long as @var{ttl}.
12437 Additionally, when @option{--cache} is used, cached entries that have
12438 not been accessed for @var{ttl} and that no longer have a corresponding
12439 item in the store, may be deleted.
12441 @item --cache-bypass-threshold=@var{size}
12442 When used in conjunction with @option{--cache}, store items smaller than
12443 @var{size} are immediately available, even when they are not yet in
12444 cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
12445 for megabytes and so on. The default is @code{10M}.
12447 ``Cache bypass'' allows you to reduce the publication delay for clients
12448 at the expense of possibly additional I/O and CPU use on the server
12449 side: depending on the client access patterns, those store items can end
12450 up being baked several times until a copy is available in cache.
12452 Increasing the threshold may be useful for sites that have few users, or
12453 to guarantee that users get substitutes even for store items that are
12456 @item --nar-path=@var{path}
12457 Use @var{path} as the prefix for the URLs of ``nar'' files
12458 (@pxref{Invoking guix archive, normalized archives}).
12460 By default, nars are served at a URL such as
12461 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
12462 change the @code{/nar} part to @var{path}.
12464 @item --public-key=@var{file}
12465 @itemx --private-key=@var{file}
12466 Use the specific @var{file}s as the public/private key pair used to sign
12467 the store items being published.
12469 The files must correspond to the same key pair (the private key is used
12470 for signing and the public key is merely advertised in the signature
12471 metadata). They must contain keys in the canonical s-expression format
12472 as produced by @command{guix archive --generate-key} (@pxref{Invoking
12473 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
12474 @file{/etc/guix/signing-key.sec} are used.
12476 @item --repl[=@var{port}]
12477 @itemx -r [@var{port}]
12478 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
12479 Reference Manual}) on @var{port} (37146 by default). This is used
12480 primarily for debugging a running @command{guix publish} server.
12483 Enabling @command{guix publish} on Guix System is a one-liner: just
12484 instantiate a @code{guix-publish-service-type} service in the @code{services} field
12485 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
12486 @code{guix-publish-service-type}}).
12488 If you are instead running Guix on a ``foreign distro'', follow these
12493 If your host distro uses the systemd init system:
12496 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
12497 /etc/systemd/system/
12498 # systemctl start guix-publish && systemctl enable guix-publish
12502 If your host distro uses the Upstart init system:
12505 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
12506 # start guix-publish
12510 Otherwise, proceed similarly with your distro's init system.
12513 @node Invoking guix challenge
12514 @section Invoking @command{guix challenge}
12516 @cindex reproducible builds
12517 @cindex verifiable builds
12518 @cindex @command{guix challenge}
12520 Do the binaries provided by this server really correspond to the source
12521 code it claims to build? Is a package build process deterministic?
12522 These are the questions the @command{guix challenge} command attempts to
12525 The former is obviously an important question: Before using a substitute
12526 server (@pxref{Substitutes}), one had better @emph{verify} that it
12527 provides the right binaries, and thus @emph{challenge} it. The latter
12528 is what enables the former: If package builds are deterministic, then
12529 independent builds of the package should yield the exact same result,
12530 bit for bit; if a server provides a binary different from the one
12531 obtained locally, it may be either corrupt or malicious.
12533 We know that the hash that shows up in @file{/gnu/store} file names is
12534 the hash of all the inputs of the process that built the file or
12535 directory---compilers, libraries, build scripts,
12536 etc. (@pxref{Introduction}). Assuming deterministic build processes,
12537 one store file name should map to exactly one build output.
12538 @command{guix challenge} checks whether there is, indeed, a single
12539 mapping by comparing the build outputs of several independent builds of
12540 any given store item.
12542 The command output looks like this:
12545 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12546 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
12547 updating list of substitutes from 'https://guix.example.org'... 100.0%
12548 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
12549 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12550 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12551 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
12553 /lib/libcrypto.so.1.1
12556 /gnu/store/@dots{}-git-2.5.0 contents differ:
12557 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
12558 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
12559 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
12561 /libexec/git-core/git-fsck
12563 /gnu/store/@dots{}-pius-2.1.1 contents differ:
12564 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12565 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12566 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
12568 /share/man/man1/pius.1.gz
12572 6,406 store items were analyzed:
12573 - 4,749 (74.1%) were identical
12574 - 525 (8.2%) differed
12575 - 1,132 (17.7%) were inconclusive
12579 In this example, @command{guix challenge} first scans the store to
12580 determine the set of locally-built derivations---as opposed to store
12581 items that were downloaded from a substitute server---and then queries
12582 all the substitute servers. It then reports those store items for which
12583 the servers obtained a result different from the local build.
12585 @cindex non-determinism, in package builds
12586 As an example, @code{guix.example.org} always gets a different answer.
12587 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
12588 case of Git. This might indicate that the build process of Git is
12589 non-deterministic, meaning that its output varies as a function of
12590 various things that Guix does not fully control, in spite of building
12591 packages in isolated environments (@pxref{Features}). Most common
12592 sources of non-determinism include the addition of timestamps in build
12593 results, the inclusion of random numbers, and directory listings sorted
12594 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
12597 To find out what is wrong with this Git binary, the easiest approach is
12601 guix challenge git \
12602 --diff=diffoscope \
12603 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12606 This automatically invokes @command{diffoscope}, which displays detailed
12607 information about files that differ.
12609 Alternatively, we can do something along these lines (@pxref{Invoking guix
12613 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
12614 | lzip -d | guix archive -x /tmp/git
12615 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
12618 This command shows the difference between the files resulting from the
12619 local build, and the files resulting from the build on
12620 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
12621 diffutils, Comparing and Merging Files}). The @command{diff} command
12622 works great for text files. When binary files differ, a better option
12623 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
12624 visualize differences for all kinds of files.
12626 Once you have done that work, you can tell whether the differences are due
12627 to a non-deterministic build process or to a malicious server. We try
12628 hard to remove sources of non-determinism in packages to make it easier
12629 to verify substitutes, but of course, this is a process that
12630 involves not just Guix, but a large part of the free software community.
12631 In the meantime, @command{guix challenge} is one tool to help address
12634 If you are writing packages for Guix, you are encouraged to check
12635 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
12636 same build result as you did with:
12639 $ guix challenge @var{package}
12643 where @var{package} is a package specification such as
12644 @code{guile@@2.0} or @code{glibc:debug}.
12646 The general syntax is:
12649 guix challenge @var{options} [@var{packages}@dots{}]
12652 When a difference is found between the hash of a locally-built item and
12653 that of a server-provided substitute, or among substitutes provided by
12654 different servers, the command displays it as in the example above and
12655 its exit code is 2 (other non-zero exit codes denote other kinds of
12658 The one option that matters is:
12662 @item --substitute-urls=@var{urls}
12663 Consider @var{urls} the whitespace-separated list of substitute source
12664 URLs to compare to.
12666 @item --diff=@var{mode}
12667 Upon mismatches, show differences according to @var{mode}, one of:
12670 @item @code{simple} (the default)
12671 Show the list of files that differ.
12673 @item @code{diffoscope}
12674 @itemx @var{command}
12675 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
12676 two directories whose contents do not match.
12678 When @var{command} is an absolute file name, run @var{command} instead
12682 Do not show further details about the differences.
12685 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
12686 downloads the store items from the given substitute servers so that it
12691 Show details about matches (identical contents) in addition to
12692 information about mismatches.
12696 @node Invoking guix copy
12697 @section Invoking @command{guix copy}
12699 @cindex copy, of store items, over SSH
12700 @cindex SSH, copy of store items
12701 @cindex sharing store items across machines
12702 @cindex transferring store items across machines
12703 The @command{guix copy} command copies items from the store of one
12704 machine to that of another machine over a secure shell (SSH)
12705 connection@footnote{This command is available only when Guile-SSH was
12706 found. @xref{Requirements}, for details.}. For example, the following
12707 command copies the @code{coreutils} package, the user's profile, and all
12708 their dependencies over to @var{host}, logged in as @var{user}:
12711 guix copy --to=@var{user}@@@var{host} \
12712 coreutils `readlink -f ~/.guix-profile`
12715 If some of the items to be copied are already present on @var{host},
12716 they are not actually sent.
12718 The command below retrieves @code{libreoffice} and @code{gimp} from
12719 @var{host}, assuming they are available there:
12722 guix copy --from=@var{host} libreoffice gimp
12725 The SSH connection is established using the Guile-SSH client, which is
12726 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
12727 @file{~/.ssh/config}, and uses the SSH agent for authentication.
12729 The key used to sign items that are sent must be accepted by the remote
12730 machine. Likewise, the key used by the remote machine to sign items you
12731 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
12732 own daemon. @xref{Invoking guix archive}, for more information about
12733 store item authentication.
12735 The general syntax is:
12738 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
12741 You must always specify one of the following options:
12744 @item --to=@var{spec}
12745 @itemx --from=@var{spec}
12746 Specify the host to send to or receive from. @var{spec} must be an SSH
12747 spec such as @code{example.org}, @code{charlie@@example.org}, or
12748 @code{charlie@@example.org:2222}.
12751 The @var{items} can be either package names, such as @code{gimp}, or
12752 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
12754 When specifying the name of a package to send, it is first built if
12755 needed, unless @option{--dry-run} was specified. Common build options
12756 are supported (@pxref{Common Build Options}).
12759 @node Invoking guix container
12760 @section Invoking @command{guix container}
12762 @cindex @command{guix container}
12764 As of version @value{VERSION}, this tool is experimental. The interface
12765 is subject to radical change in the future.
12768 The purpose of @command{guix container} is to manipulate processes
12769 running within an isolated environment, commonly known as a
12770 ``container'', typically created by the @command{guix environment}
12771 (@pxref{Invoking guix environment}) and @command{guix system container}
12772 (@pxref{Invoking guix system}) commands.
12774 The general syntax is:
12777 guix container @var{action} @var{options}@dots{}
12780 @var{action} specifies the operation to perform with a container, and
12781 @var{options} specifies the context-specific arguments for the action.
12783 The following actions are available:
12787 Execute a command within the context of a running container.
12792 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
12795 @var{pid} specifies the process ID of the running container.
12796 @var{program} specifies an executable file name within the root file
12797 system of the container. @var{arguments} are the additional options that
12798 will be passed to @var{program}.
12800 The following command launches an interactive login shell inside a
12801 Guix system container, started by @command{guix system container}, and whose
12802 process ID is 9001:
12805 guix container exec 9001 /run/current-system/profile/bin/bash --login
12808 Note that the @var{pid} cannot be the parent process of a container. It
12809 must be PID 1 of the container or one of its child processes.
12813 @node Invoking guix weather
12814 @section Invoking @command{guix weather}
12816 Occasionally you're grumpy because substitutes are lacking and you end
12817 up building packages by yourself (@pxref{Substitutes}). The
12818 @command{guix weather} command reports on substitute availability on the
12819 specified servers so you can have an idea of whether you'll be grumpy
12820 today. It can sometimes be useful info as a user, but it is primarily
12821 useful to people running @command{guix publish} (@pxref{Invoking guix
12824 @cindex statistics, for substitutes
12825 @cindex availability of substitutes
12826 @cindex substitute availability
12827 @cindex weather, substitute availability
12828 Here's a sample run:
12831 $ guix weather --substitute-urls=https://guix.example.org
12832 computing 5,872 package derivations for x86_64-linux...
12833 looking for 6,128 store items on https://guix.example.org..
12834 updating list of substitutes from 'https://guix.example.org'... 100.0%
12835 https://guix.example.org
12836 43.4% substitutes available (2,658 out of 6,128)
12837 7,032.5 MiB of nars (compressed)
12838 19,824.2 MiB on disk (uncompressed)
12839 0.030 seconds per request (182.9 seconds in total)
12840 33.5 requests per second
12842 9.8% (342 out of 3,470) of the missing items are queued
12844 x86_64-linux: 518 (59.7%)
12845 i686-linux: 221 (25.5%)
12846 aarch64-linux: 128 (14.8%)
12847 build rate: 23.41 builds per hour
12848 x86_64-linux: 11.16 builds per hour
12849 i686-linux: 6.03 builds per hour
12850 aarch64-linux: 6.41 builds per hour
12853 @cindex continuous integration, statistics
12854 As you can see, it reports the fraction of all the packages for which
12855 substitutes are available on the server---regardless of whether
12856 substitutes are enabled, and regardless of whether this server's signing
12857 key is authorized. It also reports the size of the compressed archives
12858 (``nars'') provided by the server, the size the corresponding store
12859 items occupy in the store (assuming deduplication is turned off), and
12860 the server's throughput. The second part gives continuous integration
12861 (CI) statistics, if the server supports it. In addition, using the
12862 @option{--coverage} option, @command{guix weather} can list ``important''
12863 package substitutes missing on the server (see below).
12865 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
12866 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
12867 challenge}, it ignores signatures on those substitutes, which is
12868 innocuous since the command only gathers statistics and cannot install
12871 The general syntax is:
12874 guix weather @var{options}@dots{} [@var{packages}@dots{}]
12877 When @var{packages} is omitted, @command{guix weather} checks the availability
12878 of substitutes for @emph{all} the packages, or for those specified with
12879 @option{--manifest}; otherwise it only considers the specified packages. It
12880 is also possible to query specific system types with @option{--system}.
12881 @command{guix weather} exits with a non-zero code when the fraction of
12882 available substitutes is below 100%.
12884 The available options are listed below.
12887 @item --substitute-urls=@var{urls}
12888 @var{urls} is the space-separated list of substitute server URLs to
12889 query. When this option is omitted, the default set of substitute
12890 servers is queried.
12892 @item --system=@var{system}
12893 @itemx -s @var{system}
12894 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
12895 option can be repeated, in which case @command{guix weather} will query
12896 substitutes for several system types.
12898 @item --manifest=@var{file}
12899 Instead of querying substitutes for all the packages, only ask for those
12900 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
12901 with the @code{-m} option of @command{guix package} (@pxref{Invoking
12904 This option can be repeated several times, in which case the manifests
12907 @item --coverage[=@var{count}]
12908 @itemx -c [@var{count}]
12909 Report on substitute coverage for packages: list packages with at least
12910 @var{count} dependents (zero by default) for which substitutes are
12911 unavailable. Dependent packages themselves are not listed: if @var{b} depends
12912 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
12913 @var{b} usually lacks substitutes as well. The result looks like this:
12916 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
12917 computing 8,983 package derivations for x86_64-linux...
12918 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
12919 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
12920 @value{SUBSTITUTE-URL}
12921 64.7% substitutes available (6,047 out of 9,343)
12923 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
12924 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
12925 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
12926 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
12930 What this example shows is that @code{kcoreaddons} and presumably the 58
12931 packages that depend on it have no substitutes at
12932 @code{@value{SUBSTITUTE-SERVER}}; likewise for @code{qgpgme} and the 46
12933 packages that depend on it.
12935 If you are a Guix developer, or if you are taking care of this build farm,
12936 you'll probably want to have a closer look at these packages: they may simply
12939 @item --display-missing
12940 Display the list of store items for which substitutes are missing.
12943 @node Invoking guix processes
12944 @section Invoking @command{guix processes}
12946 The @command{guix processes} command can be useful to developers and system
12947 administrators, especially on multi-user machines and on build farms: it lists
12948 the current sessions (connections to the daemon), as well as information about
12949 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
12950 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
12951 listed.}. Here's an example of the information it returns:
12954 $ sudo guix processes
12957 ClientCommand: guix environment --ad-hoc python
12961 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
12965 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
12966 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
12967 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
12968 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
12970 ChildCommand: guix offload x86_64-linux 7200 1 28800
12972 ChildCommand: guix offload x86_64-linux 7200 1 28800
12974 ChildCommand: guix offload x86_64-linux 7200 1 28800
12977 In this example we see that @command{guix-daemon} has three clients:
12978 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
12979 integration tool; their process identifier (PID) is given by the
12980 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
12981 @command{guix-daemon} sub-process of this particular session.
12983 The @code{LockHeld} fields show which store items are currently locked
12984 by this session, which corresponds to store items being built or
12985 substituted (the @code{LockHeld} field is not displayed when
12986 @command{guix processes} is not running as root). Last, by looking at
12987 the @code{ChildPID} and @code{ChildCommand} fields, we understand that
12988 these three builds are being offloaded (@pxref{Daemon Offload Setup}).
12990 The output is in Recutils format so we can use the handy @command{recsel}
12991 command to select sessions of interest (@pxref{Selection Expressions,,,
12992 recutils, GNU recutils manual}). As an example, the command shows the command
12993 line and PID of the client that triggered the build of a Perl package:
12996 $ sudo guix processes | \
12997 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
12999 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
13002 Additional options are listed below.
13005 @item --format=@var{format}
13006 @itemx -f @var{format}
13007 Produce output in the specified @var{format}, one of:
13011 The default option. It outputs a set of Session recutils records
13012 that include each @code{ChildProcess} as a field.
13015 Normalize the output records into record sets (@pxref{Record Sets,,,
13016 recutils, GNU recutils manual}). Normalizing into record sets allows
13017 joins across record types. The example below lists the PID of each
13018 @code{ChildProcess} and the associated PID for @code{Session} that
13019 spawned the @code{ChildProcess} where the @code{Session} was started
13020 using @command{guix build}.
13023 $ guix processes --format=normalized | \
13027 -p Session.PID,PID \
13028 -e 'Session.ClientCommand ~ "guix build"'
13041 @node System Configuration
13042 @chapter System Configuration
13044 @cindex system configuration
13045 Guix System supports a consistent whole-system configuration
13046 mechanism. By that we mean that all aspects of the global system
13047 configuration---such as the available system services, timezone and
13048 locale settings, user accounts---are declared in a single place. Such
13049 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
13051 One of the advantages of putting all the system configuration under the
13052 control of Guix is that it supports transactional system upgrades, and
13053 makes it possible to roll back to a previous system instantiation,
13054 should something go wrong with the new one (@pxref{Features}). Another
13055 advantage is that it makes it easy to replicate the exact same configuration
13056 across different machines, or at different points in time, without
13057 having to resort to additional administration tools layered on top of
13058 the own tools of the system.
13059 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
13061 This section describes this mechanism. First we focus on the system
13062 administrator's viewpoint---explaining how the system is configured and
13063 instantiated. Then we show how this mechanism can be extended, for
13064 instance to support new system services.
13067 * Using the Configuration System:: Customizing your GNU system.
13068 * operating-system Reference:: Detail of operating-system declarations.
13069 * File Systems:: Configuring file system mounts.
13070 * Mapped Devices:: Block device extra processing.
13071 * User Accounts:: Specifying user accounts.
13072 * Keyboard Layout:: How the system interprets key strokes.
13073 * Locales:: Language and cultural convention settings.
13074 * Services:: Specifying system services.
13075 * Setuid Programs:: Programs running with root privileges.
13076 * X.509 Certificates:: Authenticating HTTPS servers.
13077 * Name Service Switch:: Configuring libc's name service switch.
13078 * Initial RAM Disk:: Linux-Libre bootstrapping.
13079 * Bootloader Configuration:: Configuring the boot loader.
13080 * Invoking guix system:: Instantiating a system configuration.
13081 * Invoking guix deploy:: Deploying a system configuration to a remote host.
13082 * Running Guix in a VM:: How to run Guix System in a virtual machine.
13083 * Defining Services:: Adding new service definitions.
13086 @node Using the Configuration System
13087 @section Using the Configuration System
13089 The operating system is configured by providing an
13090 @code{operating-system} declaration in a file that can then be passed to
13091 the @command{guix system} command (@pxref{Invoking guix system}). A
13092 simple setup, with the default system services, the default Linux-Libre
13093 kernel, initial RAM disk, and boot loader looks like this:
13095 @findex operating-system
13097 @include os-config-bare-bones.texi
13100 This example should be self-describing. Some of the fields defined
13101 above, such as @code{host-name} and @code{bootloader}, are mandatory.
13102 Others, such as @code{packages} and @code{services}, can be omitted, in
13103 which case they get a default value.
13105 Below we discuss the effect of some of the most important fields
13106 (@pxref{operating-system Reference}, for details about all the available
13107 fields), and how to @dfn{instantiate} the operating system using
13108 @command{guix system}.
13110 @unnumberedsubsec Bootloader
13112 @cindex legacy boot, on Intel machines
13113 @cindex BIOS boot, on Intel machines
13116 The @code{bootloader} field describes the method that will be used to boot
13117 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
13118 mode, as in the example above. However, more recent machines rely instead on
13119 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
13120 the @code{bootloader} field should contain something along these lines:
13123 (bootloader-configuration
13124 (bootloader grub-efi-bootloader)
13125 (target "/boot/efi"))
13128 @xref{Bootloader Configuration}, for more information on the available
13129 configuration options.
13131 @unnumberedsubsec Globally-Visible Packages
13133 @vindex %base-packages
13134 The @code{packages} field lists packages that will be globally visible
13135 on the system, for all user accounts---i.e., in every user's @env{PATH}
13136 environment variable---in addition to the per-user profiles
13137 (@pxref{Invoking guix package}). The @code{%base-packages} variable
13138 provides all the tools one would expect for basic user and administrator
13139 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
13140 the GNU Zile lightweight text editor, @command{find}, @command{grep},
13141 etc. The example above adds GNU@tie{}Screen to those,
13142 taken from the @code{(gnu packages screen)}
13143 module (@pxref{Package Modules}). The
13144 @code{(list package output)} syntax can be used to add a specific output
13148 (use-modules (gnu packages))
13149 (use-modules (gnu packages dns))
13153 (packages (cons (list bind "utils")
13157 @findex specification->package
13158 Referring to packages by variable name, like @code{bind} above, has
13159 the advantage of being unambiguous; it also allows typos and such to be
13160 diagnosed right away as ``unbound variables''. The downside is that one
13161 needs to know which module defines which package, and to augment the
13162 @code{use-package-modules} line accordingly. To avoid that, one can use
13163 the @code{specification->package} procedure of the @code{(gnu packages)}
13164 module, which returns the best package for a given name or name and
13168 (use-modules (gnu packages))
13172 (packages (append (map specification->package
13173 '("tcpdump" "htop" "gnupg@@2.0"))
13177 @unnumberedsubsec System Services
13180 @vindex %base-services
13181 The @code{services} field lists @dfn{system services} to be made
13182 available when the system starts (@pxref{Services}).
13183 The @code{operating-system} declaration above specifies that, in
13184 addition to the basic services, we want the OpenSSH secure shell
13185 daemon listening on port 2222 (@pxref{Networking Services,
13186 @code{openssh-service-type}}). Under the hood,
13187 @code{openssh-service-type} arranges so that @command{sshd} is started with the
13188 right command-line options, possibly with supporting configuration files
13189 generated as needed (@pxref{Defining Services}).
13191 @cindex customization, of services
13192 @findex modify-services
13193 Occasionally, instead of using the base services as is, you will want to
13194 customize them. To do this, use @code{modify-services} (@pxref{Service
13195 Reference, @code{modify-services}}) to modify the list.
13197 For example, suppose you want to modify @code{guix-daemon} and Mingetty
13198 (the console log-in) in the @code{%base-services} list (@pxref{Base
13199 Services, @code{%base-services}}). To do that, you can write the
13200 following in your operating system declaration:
13203 (define %my-services
13204 ;; My very own list of services.
13205 (modify-services %base-services
13206 (guix-service-type config =>
13207 (guix-configuration
13209 ;; Fetch substitutes from example.org.
13211 (list "https://example.org/guix"
13212 "https://ci.guix.gnu.org"))))
13213 (mingetty-service-type config =>
13214 (mingetty-configuration
13216 ;; Automatially log in as "guest".
13217 (auto-login "guest")))))
13221 (services %my-services))
13224 This changes the configuration---i.e., the service parameters---of the
13225 @code{guix-service-type} instance, and that of all the
13226 @code{mingetty-service-type} instances in the @code{%base-services} list.
13227 Observe how this is accomplished: first, we arrange for the original
13228 configuration to be bound to the identifier @code{config} in the
13229 @var{body}, and then we write the @var{body} so that it evaluates to the
13230 desired configuration. In particular, notice how we use @code{inherit}
13231 to create a new configuration which has the same values as the old
13232 configuration, but with a few modifications.
13234 @cindex encrypted disk
13235 The configuration for a typical ``desktop'' usage, with an encrypted
13236 root partition, the X11 display
13237 server, GNOME and Xfce (users can choose which of these desktop
13238 environments to use at the log-in screen by pressing @kbd{F1}), network
13239 management, power management, and more, would look like this:
13242 @include os-config-desktop.texi
13245 A graphical system with a choice of lightweight window managers
13246 instead of full-blown desktop environments would look like this:
13249 @include os-config-lightweight-desktop.texi
13252 This example refers to the @file{/boot/efi} file system by its UUID,
13253 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
13254 as returned by the @command{blkid} command.
13256 @xref{Desktop Services}, for the exact list of services provided by
13257 @code{%desktop-services}. @xref{X.509 Certificates}, for background
13258 information about the @code{nss-certs} package that is used here.
13260 Again, @code{%desktop-services} is just a list of service objects. If
13261 you want to remove services from there, you can do so using the
13262 procedures for list filtering (@pxref{SRFI-1 Filtering and
13263 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
13264 following expression returns a list that contains all the services in
13265 @code{%desktop-services} minus the Avahi service:
13268 (remove (lambda (service)
13269 (eq? (service-kind service) avahi-service-type))
13273 @unnumberedsubsec Instantiating the System
13275 Assuming the @code{operating-system} declaration
13276 is stored in the @file{my-system-config.scm}
13277 file, the @command{guix system reconfigure my-system-config.scm} command
13278 instantiates that configuration, and makes it the default GRUB boot
13279 entry (@pxref{Invoking guix system}).
13281 The normal way to change the system configuration is by updating this
13282 file and re-running @command{guix system reconfigure}. One should never
13283 have to touch files in @file{/etc} or to run commands that modify the
13284 system state such as @command{useradd} or @command{grub-install}. In
13285 fact, you must avoid that since that would not only void your warranty
13286 but also prevent you from rolling back to previous versions of your
13287 system, should you ever need to.
13289 @cindex roll-back, of the operating system
13290 Speaking of roll-back, each time you run @command{guix system
13291 reconfigure}, a new @dfn{generation} of the system is created---without
13292 modifying or deleting previous generations. Old system generations get
13293 an entry in the bootloader boot menu, allowing you to boot them in case
13294 something went wrong with the latest generation. Reassuring, no? The
13295 @command{guix system list-generations} command lists the system
13296 generations available on disk. It is also possible to roll back the
13297 system via the commands @command{guix system roll-back} and
13298 @command{guix system switch-generation}.
13300 Although the @command{guix system reconfigure} command will not modify
13301 previous generations, you must take care when the current generation is not
13302 the latest (e.g., after invoking @command{guix system roll-back}), since
13303 the operation might overwrite a later generation (@pxref{Invoking guix
13306 @unnumberedsubsec The Programming Interface
13308 At the Scheme level, the bulk of an @code{operating-system} declaration
13309 is instantiated with the following monadic procedure (@pxref{The Store
13312 @deffn {Monadic Procedure} operating-system-derivation os
13313 Return a derivation that builds @var{os}, an @code{operating-system}
13314 object (@pxref{Derivations}).
13316 The output of the derivation is a single directory that refers to all
13317 the packages, configuration files, and other supporting files needed to
13318 instantiate @var{os}.
13321 This procedure is provided by the @code{(gnu system)} module. Along
13322 with @code{(gnu services)} (@pxref{Services}), this module contains the
13323 guts of Guix System. Make sure to visit it!
13326 @node operating-system Reference
13327 @section @code{operating-system} Reference
13329 This section summarizes all the options available in
13330 @code{operating-system} declarations (@pxref{Using the Configuration
13333 @deftp {Data Type} operating-system
13334 This is the data type representing an operating system configuration.
13335 By that, we mean all the global system configuration, not per-user
13336 configuration (@pxref{Using the Configuration System}).
13339 @item @code{kernel} (default: @code{linux-libre})
13340 The package object of the operating system kernel to
13341 use@footnote{Currently only the Linux-libre kernel is fully supported.
13342 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
13343 available when building a virtual machine disk image.}.
13346 @item @code{hurd} (default: @code{#f})
13347 The package object of the Hurd to be started by the kernel. When this
13348 field is set, produce a GNU/Hurd operating system. In that case,
13349 @code{kernel} must also be set to the @code{gnumach} package---the
13350 microkernel the Hurd runs on.
13353 This feature is experimental and only supported for disk images.
13356 @item @code{kernel-loadable-modules} (default: '())
13357 A list of objects (usually packages) to collect loadable kernel modules
13358 from--e.g. @code{(list ddcci-driver-linux)}.
13360 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
13361 List of strings or gexps representing additional arguments to pass on
13362 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
13364 @item @code{bootloader}
13365 The system bootloader configuration object. @xref{Bootloader Configuration}.
13368 This is the label (a string) as it appears in the bootloader's menu entry.
13369 The default label includes the kernel name and version.
13371 @item @code{keyboard-layout} (default: @code{#f})
13372 This field specifies the keyboard layout to use in the console. It can be
13373 either @code{#f}, in which case the default keyboard layout is used (usually
13374 US English), or a @code{<keyboard-layout>} record. @xref{Keyboard Layout},
13375 for more information.
13377 This keyboard layout is in effect as soon as the kernel has booted. For
13378 instance, it is the keyboard layout in effect when you type a passphrase if
13379 your root file system is on a @code{luks-device-mapping} mapped device
13380 (@pxref{Mapped Devices}).
13383 This does @emph{not} specify the keyboard layout used by the bootloader, nor
13384 that used by the graphical display server. @xref{Bootloader Configuration},
13385 for information on how to specify the bootloader's keyboard layout. @xref{X
13386 Window}, for information on how to specify the keyboard layout used by the X
13390 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
13392 @cindex initial RAM disk
13393 The list of Linux kernel modules that need to be available in the
13394 initial RAM disk. @xref{Initial RAM Disk}.
13396 @item @code{initrd} (default: @code{base-initrd})
13397 A procedure that returns an initial RAM disk for the Linux
13398 kernel. This field is provided to support low-level customization and
13399 should rarely be needed for casual use. @xref{Initial RAM Disk}.
13401 @item @code{firmware} (default: @code{%base-firmware})
13403 List of firmware packages loadable by the operating system kernel.
13405 The default includes firmware needed for Atheros- and Broadcom-based
13406 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
13407 respectively). @xref{Hardware Considerations}, for more info on
13408 supported hardware.
13410 @item @code{host-name}
13413 @item @code{hosts-file}
13415 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
13416 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
13417 Reference Manual}). The default is a file with entries for
13418 @code{localhost} and @var{host-name}.
13420 @item @code{mapped-devices} (default: @code{'()})
13421 A list of mapped devices. @xref{Mapped Devices}.
13423 @item @code{file-systems}
13424 A list of file systems. @xref{File Systems}.
13426 @cindex swap devices
13428 @item @code{swap-devices} (default: @code{'()})
13429 A list of UUIDs, file system labels, or strings identifying devices or
13430 files to be used for ``swap
13431 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
13432 Manual}). Here are some examples:
13435 @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
13436 Use the swap partition with the given UUID. You can learn the UUID of a
13437 Linux swap partition by running @command{swaplabel @var{device}}, where
13438 @var{device} is the @file{/dev} file name of that partition.
13440 @item (list (file-system-label "swap"))
13441 Use the partition with label @code{swap}. Again, the
13442 @command{swaplabel} command allows you to view and change the label of a
13443 Linux swap partition.
13445 @item (list "/swapfile")
13446 Use the file @file{/swapfile} as swap space.
13448 @item (list "/dev/sda3" "/dev/sdb2")
13449 Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
13450 We recommend referring to swap devices by UUIDs or labels as shown above
13454 It is possible to specify a swap file in a file system on a mapped
13455 device (under @file{/dev/mapper}), provided that the necessary device
13456 mapping and file system are also specified. @xref{Mapped Devices} and
13457 @ref{File Systems}.
13459 @item @code{users} (default: @code{%base-user-accounts})
13460 @itemx @code{groups} (default: @code{%base-groups})
13461 List of user accounts and groups. @xref{User Accounts}.
13463 If the @code{users} list lacks a user account with UID@tie{}0, a
13464 ``root'' account with UID@tie{}0 is automatically added.
13466 @item @code{skeletons} (default: @code{(default-skeletons)})
13467 A list of target file name/file-like object tuples (@pxref{G-Expressions,
13468 file-like objects}). These are the skeleton files that will be added to
13469 the home directory of newly-created user accounts.
13471 For instance, a valid value may look like this:
13474 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
13475 (".guile" ,(plain-file "guile"
13476 "(use-modules (ice-9 readline))
13477 (activate-readline)")))
13480 @item @code{issue} (default: @code{%default-issue})
13481 A string denoting the contents of the @file{/etc/issue} file, which is
13482 displayed when users log in on a text console.
13484 @item @code{packages} (default: @code{%base-packages})
13485 A list of packages to be installed in the global profile, which is accessible
13486 at @file{/run/current-system/profile}. Each element is either a package
13487 variable or a package/output tuple. Here's a simple example of both:
13490 (cons* git ; the default "out" output
13491 (list git "send-email") ; another output of git
13492 %base-packages) ; the default set
13495 The default set includes core utilities and it is good practice to
13496 install non-core utilities in user profiles (@pxref{Invoking guix
13499 @item @code{timezone}
13500 A timezone identifying string---e.g., @code{"Europe/Paris"}.
13502 You can run the @command{tzselect} command to find out which timezone
13503 string corresponds to your region. Choosing an invalid timezone name
13504 causes @command{guix system} to fail.
13506 @item @code{locale} (default: @code{"en_US.utf8"})
13507 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
13508 Library Reference Manual}). @xref{Locales}, for more information.
13510 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
13511 The list of locale definitions to be compiled and that may be used at
13512 run time. @xref{Locales}.
13514 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
13515 The list of GNU@tie{}libc packages whose locale data and tools are used
13516 to build the locale definitions. @xref{Locales}, for compatibility
13517 considerations that justify this option.
13519 @item @code{name-service-switch} (default: @code{%default-nss})
13520 Configuration of the libc name service switch (NSS)---a
13521 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
13524 @item @code{services} (default: @code{%base-services})
13525 A list of service objects denoting system services. @xref{Services}.
13527 @cindex essential services
13528 @item @code{essential-services} (default: ...)
13529 The list of ``essential services''---i.e., things like instances of
13530 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
13531 Reference}), which are derived from the operating system definition itself.
13532 As a user you should @emph{never} need to touch this field.
13534 @item @code{pam-services} (default: @code{(base-pam-services)})
13536 @cindex pluggable authentication modules
13537 Linux @dfn{pluggable authentication module} (PAM) services.
13538 @c FIXME: Add xref to PAM services section.
13540 @item @code{setuid-programs} (default: @code{%setuid-programs})
13541 List of string-valued G-expressions denoting setuid programs.
13542 @xref{Setuid Programs}.
13544 @item @code{sudoers-file} (default: @code{%sudoers-specification})
13545 @cindex sudoers file
13546 The contents of the @file{/etc/sudoers} file as a file-like object
13547 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
13549 This file specifies which users can use the @command{sudo} command, what
13550 they are allowed to do, and what privileges they may gain. The default
13551 is that only @code{root} and members of the @code{wheel} group may use
13556 @deffn {Scheme Syntax} this-operating-system
13557 When used in the @emph{lexical scope} of an operating system field definition,
13558 this identifier resolves to the operating system being defined.
13560 The example below shows how to refer to the operating system being defined in
13561 the definition of the @code{label} field:
13564 (use-modules (gnu) (guix))
13568 (label (package-full-name
13569 (operating-system-kernel this-operating-system))))
13572 It is an error to refer to @code{this-operating-system} outside an operating
13579 @section File Systems
13581 The list of file systems to be mounted is specified in the
13582 @code{file-systems} field of the operating system declaration
13583 (@pxref{Using the Configuration System}). Each file system is declared
13584 using the @code{file-system} form, like this:
13588 (mount-point "/home")
13589 (device "/dev/sda3")
13593 As usual, some of the fields are mandatory---those shown in the example
13594 above---while others can be omitted. These are described below.
13596 @deftp {Data Type} file-system
13597 Objects of this type represent file systems to be mounted. They
13598 contain the following members:
13602 This is a string specifying the type of the file system---e.g.,
13605 @item @code{mount-point}
13606 This designates the place where the file system is to be mounted.
13608 @item @code{device}
13609 This names the ``source'' of the file system. It can be one of three
13610 things: a file system label, a file system UUID, or the name of a
13611 @file{/dev} node. Labels and UUIDs offer a way to refer to file
13612 systems without having to hard-code their actual device
13613 name@footnote{Note that, while it is tempting to use
13614 @file{/dev/disk/by-uuid} and similar device names to achieve the same
13615 result, this is not recommended: These special device nodes are created
13616 by the udev daemon and may be unavailable at the time the device is
13619 @findex file-system-label
13620 File system labels are created using the @code{file-system-label}
13621 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
13622 plain strings. Here's an example of a file system referred to by its
13623 label, as shown by the @command{e2label} command:
13627 (mount-point "/home")
13629 (device (file-system-label "my-home")))
13633 UUIDs are converted from their string representation (as shown by the
13634 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
13635 @code{uuid} form expects 16-byte UUIDs as defined in
13636 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
13637 form of UUID used by the ext2 family of file systems and others, but it
13638 is different from ``UUIDs'' found in FAT file systems, for instance.},
13643 (mount-point "/home")
13645 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
13648 When the source of a file system is a mapped device (@pxref{Mapped
13649 Devices}), its @code{device} field @emph{must} refer to the mapped
13650 device name---e.g., @file{"/dev/mapper/root-partition"}.
13651 This is required so that
13652 the system knows that mounting the file system depends on having the
13653 corresponding device mapping established.
13655 @item @code{flags} (default: @code{'()})
13656 This is a list of symbols denoting mount flags. Recognized flags
13657 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
13658 access to special files), @code{no-suid} (ignore setuid and setgid
13659 bits), @code{no-atime} (do not update file access times),
13660 @code{strict-atime} (update file access time), @code{lazy-time} (only
13661 update time on the in-memory version of the file inode), and
13662 @code{no-exec} (disallow program execution).
13663 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
13664 Manual}, for more information on these flags.
13666 @item @code{options} (default: @code{#f})
13667 This is either @code{#f}, or a string denoting mount options passed to
13668 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
13669 Library Reference Manual}, for details and run @command{man 8 mount} for
13670 options for various file systems. Note that the
13671 @code{file-system-options->alist} and @code{alist->file-system-options}
13672 procedures from @code{(gnu system file-systems)} can be used to convert
13673 file system options given as an association list to the string
13674 representation, and vice-versa.
13676 @item @code{mount?} (default: @code{#t})
13677 This value indicates whether to automatically mount the file system when
13678 the system is brought up. When set to @code{#f}, the file system gets
13679 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
13680 is not automatically mounted.
13682 @item @code{needed-for-boot?} (default: @code{#f})
13683 This Boolean value indicates whether the file system is needed when
13684 booting. If that is true, then the file system is mounted when the
13685 initial RAM disk (initrd) is loaded. This is always the case, for
13686 instance, for the root file system.
13688 @item @code{check?} (default: @code{#t})
13689 This Boolean indicates whether the file system needs to be checked for
13690 errors before being mounted.
13692 @item @code{create-mount-point?} (default: @code{#f})
13693 When true, the mount point is created if it does not exist yet.
13695 @item @code{mount-may-fail?} (default: @code{#f})
13696 When true, this indicates that mounting this file system can fail but
13697 that should not be considered an error. This is useful in unusual
13698 cases; an example of this is @code{efivarfs}, a file system that can
13699 only be mounted on EFI/UEFI systems.
13701 @item @code{dependencies} (default: @code{'()})
13702 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
13703 representing file systems that must be mounted or mapped devices that
13704 must be opened before (and unmounted or closed after) this one.
13706 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
13707 a dependency of @file{/sys/fs/cgroup/cpu} and
13708 @file{/sys/fs/cgroup/memory}.
13710 Another example is a file system that depends on a mapped device, for
13711 example for an encrypted partition (@pxref{Mapped Devices}).
13715 @deffn {Scheme Procedure} file-system-label @var{str}
13716 This procedure returns an opaque file system label from @var{str}, a
13720 (file-system-label "home")
13721 @result{} #<file-system-label "home">
13724 File system labels are used to refer to file systems by label rather
13725 than by device name. See above for examples.
13728 The @code{(gnu system file-systems)} exports the following useful
13731 @defvr {Scheme Variable} %base-file-systems
13732 These are essential file systems that are required on normal systems,
13733 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
13734 below). Operating system declarations should always contain at least
13738 @defvr {Scheme Variable} %pseudo-terminal-file-system
13739 This is the file system to be mounted as @file{/dev/pts}. It supports
13740 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
13741 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
13742 Manual}). Pseudo-terminals are used by terminal emulators such as
13746 @defvr {Scheme Variable} %shared-memory-file-system
13747 This file system is mounted as @file{/dev/shm} and is used to support
13748 memory sharing across processes (@pxref{Memory-mapped I/O,
13749 @code{shm_open},, libc, The GNU C Library Reference Manual}).
13752 @defvr {Scheme Variable} %immutable-store
13753 This file system performs a read-only ``bind mount'' of
13754 @file{/gnu/store}, making it read-only for all the users including
13755 @code{root}. This prevents against accidental modification by software
13756 running as @code{root} or by system administrators.
13758 The daemon itself is still able to write to the store: it remounts it
13759 read-write in its own ``name space.''
13762 @defvr {Scheme Variable} %binary-format-file-system
13763 The @code{binfmt_misc} file system, which allows handling of arbitrary
13764 executable file types to be delegated to user space. This requires the
13765 @code{binfmt.ko} kernel module to be loaded.
13768 @defvr {Scheme Variable} %fuse-control-file-system
13769 The @code{fusectl} file system, which allows unprivileged users to mount
13770 and unmount user-space FUSE file systems. This requires the
13771 @code{fuse.ko} kernel module to be loaded.
13774 The @code{(gnu system uuid)} module provides tools to deal with file
13775 system ``unique identifiers'' (UUIDs).
13777 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
13778 Return an opaque UUID (unique identifier) object of the given @var{type}
13779 (a symbol) by parsing @var{str} (a string):
13782 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
13783 @result{} #<<uuid> type: dce bv: @dots{}>
13785 (uuid "1234-ABCD" 'fat)
13786 @result{} #<<uuid> type: fat bv: @dots{}>
13789 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
13790 @code{ntfs}, or one of the commonly found synonyms for these.
13792 UUIDs are another way to unambiguously refer to file systems in
13793 operating system configuration. See the examples above.
13797 @node Btrfs file system
13798 @subsection Btrfs file system
13800 The Btrfs has special features, such as subvolumes, that merit being
13801 explained in more details. The following section attempts to cover
13802 basic as well as complex uses of a Btrfs file system with the Guix
13805 In its simplest usage, a Btrfs file system can be described, for
13810 (mount-point "/home")
13812 (device (file-system-label "my-home")))
13815 The example below is more complex, as it makes use of a Btrfs
13816 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
13817 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
13818 dependency on @code{mapped-devices}):
13822 (device (file-system-label "my-btrfs-pool"))
13825 (options "subvol=rootfs")
13826 (dependencies mapped-devices))
13829 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
13830 top level during the early boot, and rely on their configuration to
13831 refer to the correct subvolume path within that top level. The
13832 bootloaders operating in this way typically produce their configuration
13833 on a running system where the Btrfs partitions are already mounted and
13834 where the subvolume information is readily available. As an example,
13835 @command{grub-mkconfig}, the configuration generator command shipped
13836 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
13837 path of a subvolume.
13839 The Guix System produces a bootloader configuration using the operating
13840 system configuration as its sole input; it is therefore necessary to
13841 extract the subvolume name on which @file{/gnu/store} lives (if any)
13842 from that operating system configuration. To better illustrate,
13843 consider a subvolume named 'rootfs' which contains the root file system
13844 data. In such situation, the GRUB bootloader would only see the top
13845 level of the root Btrfs partition, e.g.:
13849 ├── rootfs (subvolume directory)
13850 ├── gnu (normal directory)
13851 ├── store (normal directory)
13855 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
13856 of the kernel, initrd binaries and any other files referred to in the
13857 GRUB configuration that must be found during the early boot.
13859 The next example shows a nested hierarchy of subvolumes and
13864 ├── rootfs (subvolume)
13865 ├── gnu (normal directory)
13866 ├── store (subvolume)
13870 This scenario would work without mounting the 'store' subvolume.
13871 Mounting 'rootfs' is sufficient, since the subvolume name matches its
13872 intended mount point in the file system hierarchy. Alternatively, the
13873 'store' subvolume could be referred to by setting the @code{subvol}
13874 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
13876 Finally, a more contrived example of nested subvolumes:
13880 ├── root-snapshots (subvolume)
13881 ├── root-current (subvolume)
13882 ├── guix-store (subvolume)
13886 Here, the 'guix-store' subvolume doesn't match its intended mount point,
13887 so it is necessary to mount it. The subvolume must be fully specified,
13888 by passing its file name to the @code{subvol} option. To illustrate,
13889 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
13890 a file system declaration such as:
13894 (device (file-system-label "btrfs-pool-1"))
13895 (mount-point "/gnu/store")
13897 (options "subvol=root-snapshots/root-current/guix-store,\
13898 compress-force=zstd,space_cache=v2"))
13901 @node Mapped Devices
13902 @section Mapped Devices
13904 @cindex device mapping
13905 @cindex mapped devices
13906 The Linux kernel has a notion of @dfn{device mapping}: a block device,
13907 such as a hard disk partition, can be @dfn{mapped} into another device,
13908 usually in @code{/dev/mapper/},
13909 with additional processing over the data that flows through
13910 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
13911 concept of a ``mapped device'' and that of a file system: both boil down
13912 to @emph{translating} input/output operations made on a file to
13913 operations on its backing store. Thus, the Hurd implements mapped
13914 devices, like file systems, using the generic @dfn{translator} mechanism
13915 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
13916 typical example is encryption device mapping: all writes to the mapped
13917 device are encrypted, and all reads are deciphered, transparently.
13918 Guix extends this notion by considering any device or set of devices that
13919 are @dfn{transformed} in some way to create a new device; for instance,
13920 RAID devices are obtained by @dfn{assembling} several other devices, such
13921 as hard disks or partitions, into a new one that behaves as one partition.
13923 Mapped devices are declared using the @code{mapped-device} form,
13924 defined as follows; for examples, see below.
13926 @deftp {Data Type} mapped-device
13927 Objects of this type represent device mappings that will be made when
13928 the system boots up.
13932 This is either a string specifying the name of the block device to be mapped,
13933 such as @code{"/dev/sda3"}, or a list of such strings when several devices
13934 need to be assembled for creating a new one. In case of LVM this is a
13935 string specifying name of the volume group to be mapped.
13938 This string specifies the name of the resulting mapped device. For
13939 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
13940 specifying @code{"my-partition"} leads to the creation of
13941 the @code{"/dev/mapper/my-partition"} device.
13942 For RAID devices of type @code{raid-device-mapping}, the full device name
13943 such as @code{"/dev/md0"} needs to be given.
13944 LVM logical volumes of type @code{lvm-device-mapping} need to
13945 be specified as @code{"VGNAME-LVNAME"}.
13948 This list of strings specifies names of the resulting mapped devices in case
13949 there are several. The format is identical to @var{target}.
13952 This must be a @code{mapped-device-kind} object, which specifies how
13953 @var{source} is mapped to @var{target}.
13957 @defvr {Scheme Variable} luks-device-mapping
13958 This defines LUKS block device encryption using the @command{cryptsetup}
13959 command from the package with the same name. It relies on the
13960 @code{dm-crypt} Linux kernel module.
13963 @defvr {Scheme Variable} raid-device-mapping
13964 This defines a RAID device, which is assembled using the @code{mdadm}
13965 command from the package with the same name. It requires a Linux kernel
13966 module for the appropriate RAID level to be loaded, such as @code{raid456}
13967 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
13970 @cindex LVM, logical volume manager
13971 @defvr {Scheme Variable} lvm-device-mapping
13972 This defines one or more logical volumes for the Linux
13973 @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
13974 The volume group is activated by the @command{vgchange} command from the
13975 @code{lvm2} package.
13978 @cindex disk encryption
13980 The following example specifies a mapping from @file{/dev/sda3} to
13981 @file{/dev/mapper/home} using LUKS---the
13982 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
13983 standard mechanism for disk encryption.
13984 The @file{/dev/mapper/home}
13985 device can then be used as the @code{device} of a @code{file-system}
13986 declaration (@pxref{File Systems}).
13990 (source "/dev/sda3")
13992 (type luks-device-mapping))
13995 Alternatively, to become independent of device numbering, one may obtain
13996 the LUKS UUID (@dfn{unique identifier}) of the source device by a
14000 cryptsetup luksUUID /dev/sda3
14003 and use it as follows:
14007 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
14009 (type luks-device-mapping))
14012 @cindex swap encryption
14013 It is also desirable to encrypt swap space, since swap space may contain
14014 sensitive data. One way to accomplish that is to use a swap file in a
14015 file system on a device mapped via LUKS encryption. In this way, the
14016 swap file is encrypted because the entire device is encrypted.
14017 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
14019 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
14020 may be declared as follows:
14024 (source (list "/dev/sda1" "/dev/sdb1"))
14025 (target "/dev/md0")
14026 (type raid-device-mapping))
14029 The @file{/dev/md0} device can then be used as the @code{device} of a
14030 @code{file-system} declaration (@pxref{File Systems}).
14031 Note that the RAID level need not be given; it is chosen during the
14032 initial creation and formatting of the RAID device and is determined
14033 automatically later.
14035 LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
14036 be declared as follows:
14041 (target (list "vg0-alpha" "vg0-beta"))
14042 (type lvm-device-mapping))
14045 Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
14046 then be used as the @code{device} of a @code{file-system} declaration
14047 (@pxref{File Systems}).
14049 @node User Accounts
14050 @section User Accounts
14054 @cindex user accounts
14055 User accounts and groups are entirely managed through the
14056 @code{operating-system} declaration. They are specified with the
14057 @code{user-account} and @code{user-group} forms:
14063 (supplementary-groups '("wheel" ;allow use of sudo, etc.
14064 "audio" ;sound card
14065 "video" ;video devices such as webcams
14066 "cdrom")) ;the good ol' CD-ROM
14067 (comment "Bob's sister"))
14070 Here's a user account that uses a different shell and a custom home
14071 directory (the default would be @file{"/home/bob"}):
14077 (comment "Alice's bro")
14078 (shell (file-append zsh "/bin/zsh"))
14079 (home-directory "/home/robert"))
14082 When booting or upon completion of @command{guix system reconfigure},
14083 the system ensures that only the user accounts and groups specified in
14084 the @code{operating-system} declaration exist, and with the specified
14085 properties. Thus, account or group creations or modifications made by
14086 directly invoking commands such as @command{useradd} are lost upon
14087 reconfiguration or reboot. This ensures that the system remains exactly
14090 @deftp {Data Type} user-account
14091 Objects of this type represent user accounts. The following members may
14096 The name of the user account.
14100 This is the name (a string) or identifier (a number) of the user group
14101 this account belongs to.
14103 @item @code{supplementary-groups} (default: @code{'()})
14104 Optionally, this can be defined as a list of group names that this
14105 account belongs to.
14107 @item @code{uid} (default: @code{#f})
14108 This is the user ID for this account (a number), or @code{#f}. In the
14109 latter case, a number is automatically chosen by the system when the
14110 account is created.
14112 @item @code{comment} (default: @code{""})
14113 A comment about the account, such as the account owner's full name.
14115 @item @code{home-directory}
14116 This is the name of the home directory for the account.
14118 @item @code{create-home-directory?} (default: @code{#t})
14119 Indicates whether the home directory of this account should be created
14120 if it does not exist yet.
14122 @item @code{shell} (default: Bash)
14123 This is a G-expression denoting the file name of a program to be used as
14124 the shell (@pxref{G-Expressions}). For example, you would refer to the
14125 Bash executable like this:
14128 (file-append bash "/bin/bash")
14132 ... and to the Zsh executable like that:
14135 (file-append zsh "/bin/zsh")
14138 @item @code{system?} (default: @code{#f})
14139 This Boolean value indicates whether the account is a ``system''
14140 account. System accounts are sometimes treated specially; for instance,
14141 graphical login managers do not list them.
14143 @anchor{user-account-password}
14144 @cindex password, for user accounts
14145 @item @code{password} (default: @code{#f})
14146 You would normally leave this field to @code{#f}, initialize user
14147 passwords as @code{root} with the @command{passwd} command, and then let
14148 users change it with @command{passwd}. Passwords set with
14149 @command{passwd} are of course preserved across reboot and
14152 If you @emph{do} want to set an initial password for an account, then
14153 this field must contain the encrypted password, as a string. You can use the
14154 @code{crypt} procedure for this purpose:
14161 ;; Specify a SHA-512-hashed initial password.
14162 (password (crypt "InitialPassword!" "$6$abc")))
14166 The hash of this initial password will be available in a file in
14167 @file{/gnu/store}, readable by all the users, so this method must be used with
14171 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
14172 more information on password encryption, and @ref{Encryption,,, guile, GNU
14173 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
14179 User group declarations are even simpler:
14182 (user-group (name "students"))
14185 @deftp {Data Type} user-group
14186 This type is for, well, user groups. There are just a few fields:
14190 The name of the group.
14192 @item @code{id} (default: @code{#f})
14193 The group identifier (a number). If @code{#f}, a new number is
14194 automatically allocated when the group is created.
14196 @item @code{system?} (default: @code{#f})
14197 This Boolean value indicates whether the group is a ``system'' group.
14198 System groups have low numerical IDs.
14200 @item @code{password} (default: @code{#f})
14201 What, user groups can have a password? Well, apparently yes. Unless
14202 @code{#f}, this field specifies the password of the group.
14207 For convenience, a variable lists all the basic user groups one may
14210 @defvr {Scheme Variable} %base-groups
14211 This is the list of basic user groups that users and/or packages expect
14212 to be present on the system. This includes groups such as ``root'',
14213 ``wheel'', and ``users'', as well as groups used to control access to
14214 specific devices such as ``audio'', ``disk'', and ``cdrom''.
14217 @defvr {Scheme Variable} %base-user-accounts
14218 This is the list of basic system accounts that programs may expect to
14219 find on a GNU/Linux system, such as the ``nobody'' account.
14221 Note that the ``root'' account is not included here. It is a
14222 special-case and is automatically added whether or not it is specified.
14225 @node Keyboard Layout
14226 @section Keyboard Layout
14228 @cindex keyboard layout
14230 To specify what each key of your keyboard does, you need to tell the operating
14231 system what @dfn{keyboard layout} you want to use. The default, when nothing
14232 is specified, is the US English QWERTY layout for 105-key PC keyboards.
14233 However, German speakers will usually prefer the German QWERTZ layout, French
14234 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
14235 or bépo, and they might even want to further customize the effect of some of
14236 the keys. This section explains how to get that done.
14238 @cindex keyboard layout, definition
14239 There are three components that will want to know about your keyboard layout:
14243 The @emph{bootloader} may want to know what keyboard layout you want to use
14244 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
14245 you want, for instance, to make sure that you can type the passphrase of your
14246 encrypted root partition using the right layout.
14249 The @emph{operating system kernel}, Linux, will need that so that the console
14250 is properly configured (@pxref{operating-system Reference,
14251 @code{keyboard-layout}}).
14254 The @emph{graphical display server}, usually Xorg, also has its own idea of
14255 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
14258 Guix allows you to configure all three separately but, fortunately, it allows
14259 you to share the same keyboard layout for all three components.
14261 @cindex XKB, keyboard layouts
14262 Keyboard layouts are represented by records created by the
14263 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
14264 the X Keyboard extension (XKB), each layout has four attributes: a name (often
14265 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
14266 optional variant name, an optional keyboard model name, and a possibly empty
14267 list of additional options. In most cases the layout name is all you care
14270 @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
14271 [#:model] [#:options '()]
14272 Return a new keyboard layout with the given @var{name} and @var{variant}.
14274 @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
14275 string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
14276 @code{xkeyboard-config} package for valid options.
14279 Here are a few examples:
14282 ;; The German QWERTZ layout. Here we assume a standard
14283 ;; "pc105" keyboard model.
14284 (keyboard-layout "de")
14286 ;; The bépo variant of the French layout.
14287 (keyboard-layout "fr" "bepo")
14289 ;; The Catalan layout.
14290 (keyboard-layout "es" "cat")
14292 ;; Arabic layout with "Alt-Shift" to switch to US layout.
14293 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
14295 ;; The Latin American Spanish layout. In addition, the
14296 ;; "Caps Lock" key is used as an additional "Ctrl" key,
14297 ;; and the "Menu" key is used as a "Compose" key to enter
14298 ;; accented letters.
14299 (keyboard-layout "latam"
14300 #:options '("ctrl:nocaps" "compose:menu"))
14302 ;; The Russian layout for a ThinkPad keyboard.
14303 (keyboard-layout "ru" #:model "thinkpad")
14305 ;; The "US international" layout, which is the US layout plus
14306 ;; dead keys to enter accented characters. This is for an
14307 ;; Apple MacBook keyboard.
14308 (keyboard-layout "us" "intl" #:model "macbook78")
14311 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
14312 for a complete list of supported layouts, variants, and models.
14314 @cindex keyboard layout, configuration
14315 Let's say you want your system to use the Turkish keyboard layout throughout
14316 your system---bootloader, console, and Xorg. Here's what your system
14317 configuration would look like:
14319 @findex set-xorg-configuration
14321 ;; Using the Turkish layout for the bootloader, the console,
14326 (keyboard-layout (keyboard-layout "tr")) ;for the console
14327 (bootloader (bootloader-configuration
14328 (bootloader grub-efi-bootloader)
14329 (target "/boot/efi")
14330 (keyboard-layout keyboard-layout))) ;for GRUB
14331 (services (cons (set-xorg-configuration
14332 (xorg-configuration ;for Xorg
14333 (keyboard-layout keyboard-layout)))
14334 %desktop-services)))
14337 In the example above, for GRUB and for Xorg, we just refer to the
14338 @code{keyboard-layout} field defined above, but we could just as well refer to
14339 a different layout. The @code{set-xorg-configuration} procedure communicates
14340 the desired Xorg configuration to the graphical log-in manager, by default
14343 We've discussed how to specify the @emph{default} keyboard layout of your
14344 system when it starts, but you can also adjust it at run time:
14348 If you're using GNOME, its settings panel has a ``Region & Language'' entry
14349 where you can select one or more keyboard layouts.
14352 Under Xorg, the @command{setxkbmap} command (from the same-named package)
14353 allows you to change the current layout. For example, this is how you would
14354 change the layout to US Dvorak:
14357 setxkbmap us dvorak
14361 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
14362 console. However, note that @code{loadkeys} does @emph{not} use the XKB
14363 keyboard layout categorization described above. The command below loads the
14364 French bépo layout:
14375 A @dfn{locale} defines cultural conventions for a particular language
14376 and region of the world (@pxref{Locales,,, libc, The GNU C Library
14377 Reference Manual}). Each locale has a name that typically has the form
14378 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
14379 @code{fr_LU.utf8} designates the locale for the French language, with
14380 cultural conventions from Luxembourg, and using the UTF-8 encoding.
14382 @cindex locale definition
14383 Usually, you will want to specify the default locale for the machine
14384 using the @code{locale} field of the @code{operating-system} declaration
14385 (@pxref{operating-system Reference, @code{locale}}).
14387 The selected locale is automatically added to the @dfn{locale
14388 definitions} known to the system if needed, with its codeset inferred
14389 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
14390 @code{UTF-8} codeset. Additional locale definitions can be specified in
14391 the @code{locale-definitions} slot of @code{operating-system}---this is
14392 useful, for instance, if the codeset could not be inferred from the
14393 locale name. The default set of locale definitions includes some widely
14394 used locales, but not all the available locales, in order to save space.
14396 For instance, to add the North Frisian locale for Germany, the value of
14400 (cons (locale-definition
14401 (name "fy_DE.utf8") (source "fy_DE"))
14402 %default-locale-definitions)
14405 Likewise, to save space, one might want @code{locale-definitions} to
14406 list only the locales that are actually used, as in:
14409 (list (locale-definition
14410 (name "ja_JP.eucjp") (source "ja_JP")
14411 (charset "EUC-JP")))
14415 The compiled locale definitions are available at
14416 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
14417 version, which is the default location where the GNU@tie{}libc provided
14418 by Guix looks for locale data. This can be overridden using the
14419 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
14420 @env{LOCPATH} and locale packages}).
14422 The @code{locale-definition} form is provided by the @code{(gnu system
14423 locale)} module. Details are given below.
14425 @deftp {Data Type} locale-definition
14426 This is the data type of a locale definition.
14431 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
14432 Reference Manual}, for more information on locale names.
14434 @item @code{source}
14435 The name of the source for that locale. This is typically the
14436 @code{@var{language}_@var{territory}} part of the locale name.
14438 @item @code{charset} (default: @code{"UTF-8"})
14439 The ``character set'' or ``code set'' for that locale,
14440 @uref{https://www.iana.org/assignments/character-sets, as defined by
14446 @defvr {Scheme Variable} %default-locale-definitions
14447 A list of commonly used UTF-8 locales, used as the default
14448 value of the @code{locale-definitions} field of @code{operating-system}
14451 @cindex locale name
14452 @cindex normalized codeset in locale names
14453 These locale definitions use the @dfn{normalized codeset} for the part
14454 that follows the dot in the name (@pxref{Using gettextized software,
14455 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
14456 instance it has @code{uk_UA.utf8} but @emph{not}, say,
14457 @code{uk_UA.UTF-8}.
14460 @subsection Locale Data Compatibility Considerations
14462 @cindex incompatibility, of locale data
14463 @code{operating-system} declarations provide a @code{locale-libcs} field
14464 to specify the GNU@tie{}libc packages that are used to compile locale
14465 declarations (@pxref{operating-system Reference}). ``Why would I
14466 care?'', you may ask. Well, it turns out that the binary format of
14467 locale data is occasionally incompatible from one libc version to
14470 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
14471 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
14472 For instance, a program linked against libc version 2.21 is unable to
14473 read locale data produced with libc 2.22; worse, that program
14474 @emph{aborts} instead of simply ignoring the incompatible locale
14475 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
14476 the incompatible locale data, which is already an improvement.}.
14477 Similarly, a program linked against libc 2.22 can read most, but not
14478 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
14479 data is incompatible); thus calls to @code{setlocale} may fail, but
14480 programs will not abort.
14482 The ``problem'' with Guix is that users have a lot of freedom: They can
14483 choose whether and when to upgrade software in their profiles, and might
14484 be using a libc version different from the one the system administrator
14485 used to build the system-wide locale data.
14487 Fortunately, unprivileged users can also install their own locale data
14488 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
14489 @env{GUIX_LOCPATH} and locale packages}).
14491 Still, it is best if the system-wide locale data at
14492 @file{/run/current-system/locale} is built for all the libc versions
14493 actually in use on the system, so that all the programs can access
14494 it---this is especially crucial on a multi-user system. To do that, the
14495 administrator can specify several libc packages in the
14496 @code{locale-libcs} field of @code{operating-system}:
14499 (use-package-modules base)
14503 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
14506 This example would lead to a system containing locale definitions for
14507 both libc 2.21 and the current version of libc in
14508 @file{/run/current-system/locale}.
14514 @cindex system services
14515 An important part of preparing an @code{operating-system} declaration is
14516 listing @dfn{system services} and their configuration (@pxref{Using the
14517 Configuration System}). System services are typically daemons launched
14518 when the system boots, or other actions needed at that time---e.g.,
14519 configuring network access.
14521 Guix has a broad definition of ``service'' (@pxref{Service
14522 Composition}), but many services are managed by the GNU@tie{}Shepherd
14523 (@pxref{Shepherd Services}). On a running system, the @command{herd}
14524 command allows you to list the available services, show their status,
14525 start and stop them, or do other specific operations (@pxref{Jump
14526 Start,,, shepherd, The GNU Shepherd Manual}). For example:
14532 The above command, run as @code{root}, lists the currently defined
14533 services. The @command{herd doc} command shows a synopsis of the given
14534 service and its associated actions:
14538 Run libc's name service cache daemon (nscd).
14540 # herd doc nscd action invalidate
14541 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
14544 The @command{start}, @command{stop}, and @command{restart} sub-commands
14545 have the effect you would expect. For instance, the commands below stop
14546 the nscd service and restart the Xorg display server:
14550 Service nscd has been stopped.
14551 # herd restart xorg-server
14552 Service xorg-server has been stopped.
14553 Service xorg-server has been started.
14556 The following sections document the available services, starting with
14557 the core services, that may be used in an @code{operating-system}
14561 * Base Services:: Essential system services.
14562 * Scheduled Job Execution:: The mcron service.
14563 * Log Rotation:: The rottlog service.
14564 * Networking Services:: Network setup, SSH daemon, etc.
14565 * Unattended Upgrades:: Automated system upgrades.
14566 * X Window:: Graphical display.
14567 * Printing Services:: Local and remote printer support.
14568 * Desktop Services:: D-Bus and desktop services.
14569 * Sound Services:: ALSA and Pulseaudio services.
14570 * Database Services:: SQL databases, key-value stores, etc.
14571 * Mail Services:: IMAP, POP3, SMTP, and all that.
14572 * Messaging Services:: Messaging services.
14573 * Telephony Services:: Telephony services.
14574 * Monitoring Services:: Monitoring services.
14575 * Kerberos Services:: Kerberos services.
14576 * LDAP Services:: LDAP services.
14577 * Web Services:: Web servers.
14578 * Certificate Services:: TLS certificates via Let's Encrypt.
14579 * DNS Services:: DNS daemons.
14580 * VPN Services:: VPN daemons.
14581 * Network File System:: NFS related services.
14582 * Continuous Integration:: The Cuirass service.
14583 * Power Management Services:: Extending battery life.
14584 * Audio Services:: The MPD.
14585 * Virtualization Services:: Virtualization services.
14586 * Version Control Services:: Providing remote access to Git repositories.
14587 * Game Services:: Game servers.
14588 * PAM Mount Service:: Service to mount volumes when logging in.
14589 * Guix Services:: Services relating specifically to Guix.
14590 * Linux Services:: Services tied to the Linux kernel.
14591 * Hurd Services:: Services specific for a Hurd System.
14592 * Miscellaneous Services:: Other services.
14595 @node Base Services
14596 @subsection Base Services
14598 The @code{(gnu services base)} module provides definitions for the basic
14599 services that one expects from the system. The services exported by
14600 this module are listed below.
14602 @defvr {Scheme Variable} %base-services
14603 This variable contains a list of basic services (@pxref{Service Types
14604 and Services}, for more information on service objects) one would
14605 expect from the system: a login service (mingetty) on each tty, syslogd,
14606 the libc name service cache daemon (nscd), the udev device manager, and
14609 This is the default value of the @code{services} field of
14610 @code{operating-system} declarations. Usually, when customizing a
14611 system, you will want to append services to @code{%base-services}, like
14615 (append (list (service avahi-service-type)
14616 (service openssh-service-type))
14621 @defvr {Scheme Variable} special-files-service-type
14622 This is the service that sets up ``special files'' such as
14623 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
14625 The value associated with @code{special-files-service-type} services
14626 must be a list of tuples where the first element is the ``special file''
14627 and the second element is its target. By default it is:
14629 @cindex @file{/bin/sh}
14630 @cindex @file{sh}, in @file{/bin}
14632 `(("/bin/sh" ,(file-append bash "/bin/sh")))
14635 @cindex @file{/usr/bin/env}
14636 @cindex @file{env}, in @file{/usr/bin}
14637 If you want to add, say, @code{/usr/bin/env} to your system, you can
14641 `(("/bin/sh" ,(file-append bash "/bin/sh"))
14642 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
14645 Since this is part of @code{%base-services}, you can use
14646 @code{modify-services} to customize the set of special files
14647 (@pxref{Service Reference, @code{modify-services}}). But the simple way
14648 to add a special file is @i{via} the @code{extra-special-file} procedure
14652 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
14653 Use @var{target} as the ``special file'' @var{file}.
14655 For example, adding the following lines to the @code{services} field of
14656 your operating system declaration leads to a @file{/usr/bin/env}
14660 (extra-special-file "/usr/bin/env"
14661 (file-append coreutils "/bin/env"))
14665 @deffn {Scheme Procedure} host-name-service @var{name}
14666 Return a service that sets the host name to @var{name}.
14669 @defvr {Scheme Variable} console-font-service-type
14670 Install the given fonts on the specified ttys (fonts are per
14671 virtual console on the kernel Linux). The value of this service is a list of
14672 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
14673 package or any valid argument to @command{setfont}, as in this example:
14676 `(("tty1" . "LatGrkCyr-8x16")
14677 ("tty2" . ,(file-append
14679 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
14680 ("tty3" . ,(file-append
14682 "/share/consolefonts/ter-132n"))) ; for HDPI
14686 @deffn {Scheme Procedure} login-service @var{config}
14687 Return a service to run login according to @var{config}, a
14688 @code{<login-configuration>} object, which specifies the message of the day,
14689 among other things.
14692 @deftp {Data Type} login-configuration
14693 This is the data type representing the configuration of login.
14698 @cindex message of the day
14699 A file-like object containing the ``message of the day''.
14701 @item @code{allow-empty-passwords?} (default: @code{#t})
14702 Allow empty passwords by default so that first-time users can log in when
14703 the 'root' account has just been created.
14708 @deffn {Scheme Procedure} mingetty-service @var{config}
14709 Return a service to run mingetty according to @var{config}, a
14710 @code{<mingetty-configuration>} object, which specifies the tty to run, among
14714 @deftp {Data Type} mingetty-configuration
14715 This is the data type representing the configuration of Mingetty, which
14716 provides the default implementation of virtual console log-in.
14721 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
14723 @item @code{auto-login} (default: @code{#f})
14724 When true, this field must be a string denoting the user name under
14725 which the system automatically logs in. When it is @code{#f}, a
14726 user name and password must be entered to log in.
14728 @item @code{login-program} (default: @code{#f})
14729 This must be either @code{#f}, in which case the default log-in program
14730 is used (@command{login} from the Shadow tool suite), or a gexp denoting
14731 the name of the log-in program.
14733 @item @code{login-pause?} (default: @code{#f})
14734 When set to @code{#t} in conjunction with @var{auto-login}, the user
14735 will have to press a key before the log-in shell is launched.
14737 @item @code{clear-on-logout?} (default: @code{#t})
14738 When set to @code{#t}, the screen will be cleared after logout.
14740 @item @code{mingetty} (default: @var{mingetty})
14741 The Mingetty package to use.
14746 @deffn {Scheme Procedure} agetty-service @var{config}
14747 Return a service to run agetty according to @var{config}, an
14748 @code{<agetty-configuration>} object, which specifies the tty to run,
14749 among other things.
14752 @deftp {Data Type} agetty-configuration
14753 This is the data type representing the configuration of agetty, which
14754 implements virtual and serial console log-in. See the @code{agetty(8)}
14755 man page for more information.
14760 The name of the console this agetty runs on, as a string---e.g.,
14761 @code{"ttyS0"}. This argument is optional, it will default to
14762 a reasonable default serial port used by the kernel Linux.
14764 For this, if there is a value for an option @code{agetty.tty} in the kernel
14765 command line, agetty will extract the device name of the serial port
14766 from it and use that.
14768 If not and if there is a value for an option @code{console} with a tty in
14769 the Linux command line, agetty will extract the device name of the
14770 serial port from it and use that.
14772 In both cases, agetty will leave the other serial device settings
14773 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
14776 @item @code{baud-rate} (default: @code{#f})
14777 A string containing a comma-separated list of one or more baud rates, in
14780 @item @code{term} (default: @code{#f})
14781 A string containing the value used for the @env{TERM} environment
14784 @item @code{eight-bits?} (default: @code{#f})
14785 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
14788 @item @code{auto-login} (default: @code{#f})
14789 When passed a login name, as a string, the specified user will be logged
14790 in automatically without prompting for their login name or password.
14792 @item @code{no-reset?} (default: @code{#f})
14793 When @code{#t}, don't reset terminal cflags (control modes).
14795 @item @code{host} (default: @code{#f})
14796 This accepts a string containing the ``login_host'', which will be written
14797 into the @file{/var/run/utmpx} file.
14799 @item @code{remote?} (default: @code{#f})
14800 When set to @code{#t} in conjunction with @var{host}, this will add an
14801 @code{-r} fakehost option to the command line of the login program
14802 specified in @var{login-program}.
14804 @item @code{flow-control?} (default: @code{#f})
14805 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
14807 @item @code{no-issue?} (default: @code{#f})
14808 When set to @code{#t}, the contents of the @file{/etc/issue} file will
14809 not be displayed before presenting the login prompt.
14811 @item @code{init-string} (default: @code{#f})
14812 This accepts a string that will be sent to the tty or modem before
14813 sending anything else. It can be used to initialize a modem.
14815 @item @code{no-clear?} (default: @code{#f})
14816 When set to @code{#t}, agetty will not clear the screen before showing
14819 @item @code{login-program} (default: (file-append shadow "/bin/login"))
14820 This must be either a gexp denoting the name of a log-in program, or
14821 unset, in which case the default value is the @command{login} from the
14824 @item @code{local-line} (default: @code{#f})
14825 Control the CLOCAL line flag. This accepts one of three symbols as
14826 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
14827 the default value chosen by agetty is @code{'auto}.
14829 @item @code{extract-baud?} (default: @code{#f})
14830 When set to @code{#t}, instruct agetty to try to extract the baud rate
14831 from the status messages produced by certain types of modems.
14833 @item @code{skip-login?} (default: @code{#f})
14834 When set to @code{#t}, do not prompt the user for a login name. This
14835 can be used with @var{login-program} field to use non-standard login
14838 @item @code{no-newline?} (default: @code{#f})
14839 When set to @code{#t}, do not print a newline before printing the
14840 @file{/etc/issue} file.
14842 @c Is this dangerous only when used with login-program, or always?
14843 @item @code{login-options} (default: @code{#f})
14844 This option accepts a string containing options that are passed to the
14845 login program. When used with the @var{login-program}, be aware that a
14846 malicious user could try to enter a login name containing embedded
14847 options that could be parsed by the login program.
14849 @item @code{login-pause} (default: @code{#f})
14850 When set to @code{#t}, wait for any key before showing the login prompt.
14851 This can be used in conjunction with @var{auto-login} to save memory by
14852 lazily spawning shells.
14854 @item @code{chroot} (default: @code{#f})
14855 Change root to the specified directory. This option accepts a directory
14858 @item @code{hangup?} (default: @code{#f})
14859 Use the Linux system call @code{vhangup} to do a virtual hangup of the
14860 specified terminal.
14862 @item @code{keep-baud?} (default: @code{#f})
14863 When set to @code{#t}, try to keep the existing baud rate. The baud
14864 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
14867 @item @code{timeout} (default: @code{#f})
14868 When set to an integer value, terminate if no user name could be read
14869 within @var{timeout} seconds.
14871 @item @code{detect-case?} (default: @code{#f})
14872 When set to @code{#t}, turn on support for detecting an uppercase-only
14873 terminal. This setting will detect a login name containing only
14874 uppercase letters as indicating an uppercase-only terminal and turn on
14875 some upper-to-lower case conversions. Note that this will not support
14876 Unicode characters.
14878 @item @code{wait-cr?} (default: @code{#f})
14879 When set to @code{#t}, wait for the user or modem to send a
14880 carriage-return or linefeed character before displaying
14881 @file{/etc/issue} or login prompt. This is typically used with the
14882 @var{init-string} option.
14884 @item @code{no-hints?} (default: @code{#f})
14885 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
14888 @item @code{no-hostname?} (default: @code{#f})
14889 By default, the hostname is printed. When this option is set to
14890 @code{#t}, no hostname will be shown at all.
14892 @item @code{long-hostname?} (default: @code{#f})
14893 By default, the hostname is only printed until the first dot. When this
14894 option is set to @code{#t}, the fully qualified hostname by
14895 @code{gethostname} or @code{getaddrinfo} is shown.
14897 @item @code{erase-characters} (default: @code{#f})
14898 This option accepts a string of additional characters that should be
14899 interpreted as backspace when the user types their login name.
14901 @item @code{kill-characters} (default: @code{#f})
14902 This option accepts a string that should be interpreted to mean ``ignore
14903 all previous characters'' (also called a ``kill'' character) when the user
14904 types their login name.
14906 @item @code{chdir} (default: @code{#f})
14907 This option accepts, as a string, a directory path that will be changed
14910 @item @code{delay} (default: @code{#f})
14911 This options accepts, as an integer, the number of seconds to sleep
14912 before opening the tty and displaying the login prompt.
14914 @item @code{nice} (default: @code{#f})
14915 This option accepts, as an integer, the nice value with which to run the
14916 @command{login} program.
14918 @item @code{extra-options} (default: @code{'()})
14919 This option provides an ``escape hatch'' for the user to provide arbitrary
14920 command-line arguments to @command{agetty} as a list of strings.
14925 @deffn {Scheme Procedure} kmscon-service-type @var{config}
14926 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
14927 according to @var{config}, a @code{<kmscon-configuration>} object, which
14928 specifies the tty to run, among other things.
14931 @deftp {Data Type} kmscon-configuration
14932 This is the data type representing the configuration of Kmscon, which
14933 implements virtual console log-in.
14937 @item @code{virtual-terminal}
14938 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
14940 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
14941 A gexp denoting the name of the log-in program. The default log-in program is
14942 @command{login} from the Shadow tool suite.
14944 @item @code{login-arguments} (default: @code{'("-p")})
14945 A list of arguments to pass to @command{login}.
14947 @item @code{auto-login} (default: @code{#f})
14948 When passed a login name, as a string, the specified user will be logged
14949 in automatically without prompting for their login name or password.
14951 @item @code{hardware-acceleration?} (default: #f)
14952 Whether to use hardware acceleration.
14954 @item @code{kmscon} (default: @var{kmscon})
14955 The Kmscon package to use.
14960 @cindex name service cache daemon
14962 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
14963 [#:name-services '()]
14964 Return a service that runs the libc name service cache daemon (nscd) with the
14965 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
14966 Service Switch}, for an example.
14968 For convenience, the Shepherd service for nscd provides the following actions:
14972 @cindex cache invalidation, nscd
14973 @cindex nscd, cache invalidation
14974 This invalidate the given cache. For instance, running:
14977 herd invalidate nscd hosts
14981 invalidates the host name lookup cache of nscd.
14984 Running @command{herd statistics nscd} displays information about nscd usage
14990 @defvr {Scheme Variable} %nscd-default-configuration
14991 This is the default @code{<nscd-configuration>} value (see below) used
14992 by @code{nscd-service}. It uses the caches defined by
14993 @code{%nscd-default-caches}; see below.
14996 @deftp {Data Type} nscd-configuration
14997 This is the data type representing the name service cache daemon (nscd)
15002 @item @code{name-services} (default: @code{'()})
15003 List of packages denoting @dfn{name services} that must be visible to
15004 the nscd---e.g., @code{(list @var{nss-mdns})}.
15006 @item @code{glibc} (default: @var{glibc})
15007 Package object denoting the GNU C Library providing the @command{nscd}
15010 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
15011 Name of the nscd log file. This is where debugging output goes when
15012 @code{debug-level} is strictly positive.
15014 @item @code{debug-level} (default: @code{0})
15015 Integer denoting the debugging levels. Higher numbers mean that more
15016 debugging output is logged.
15018 @item @code{caches} (default: @code{%nscd-default-caches})
15019 List of @code{<nscd-cache>} objects denoting things to be cached; see
15025 @deftp {Data Type} nscd-cache
15026 Data type representing a cache database of nscd and its parameters.
15030 @item @code{database}
15031 This is a symbol representing the name of the database to be cached.
15032 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
15033 @code{services}, which designate the corresponding NSS database
15034 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
15036 @item @code{positive-time-to-live}
15037 @itemx @code{negative-time-to-live} (default: @code{20})
15038 A number representing the number of seconds during which a positive or
15039 negative lookup result remains in cache.
15041 @item @code{check-files?} (default: @code{#t})
15042 Whether to check for updates of the files corresponding to
15045 For instance, when @var{database} is @code{hosts}, setting this flag
15046 instructs nscd to check for updates in @file{/etc/hosts} and to take
15049 @item @code{persistent?} (default: @code{#t})
15050 Whether the cache should be stored persistently on disk.
15052 @item @code{shared?} (default: @code{#t})
15053 Whether the cache should be shared among users.
15055 @item @code{max-database-size} (default: 32@tie{}MiB)
15056 Maximum size in bytes of the database cache.
15058 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
15059 @c settings, so leave them out.
15064 @defvr {Scheme Variable} %nscd-default-caches
15065 List of @code{<nscd-cache>} objects used by default by
15066 @code{nscd-configuration} (see above).
15068 It enables persistent and aggressive caching of service and host name
15069 lookups. The latter provides better host name lookup performance,
15070 resilience in the face of unreliable name servers, and also better
15071 privacy---often the result of host name lookups is in local cache, so
15072 external name servers do not even need to be queried.
15075 @anchor{syslog-configuration-type}
15078 @deftp {Data Type} syslog-configuration
15079 This data type represents the configuration of the syslog daemon.
15082 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
15083 The syslog daemon to use.
15085 @item @code{config-file} (default: @code{%default-syslog.conf})
15086 The syslog configuration file to use.
15091 @anchor{syslog-service}
15093 @deffn {Scheme Procedure} syslog-service @var{config}
15094 Return a service that runs a syslog daemon according to @var{config}.
15096 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
15097 information on the configuration file syntax.
15100 @defvr {Scheme Variable} guix-service-type
15101 This is the type of the service that runs the build daemon,
15102 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
15103 @code{guix-configuration} record as described below.
15106 @anchor{guix-configuration-type}
15107 @deftp {Data Type} guix-configuration
15108 This data type represents the configuration of the Guix build daemon.
15109 @xref{Invoking guix-daemon}, for more information.
15112 @item @code{guix} (default: @var{guix})
15113 The Guix package to use.
15115 @item @code{build-group} (default: @code{"guixbuild"})
15116 Name of the group for build user accounts.
15118 @item @code{build-accounts} (default: @code{10})
15119 Number of build user accounts to create.
15121 @item @code{authorize-key?} (default: @code{#t})
15122 @cindex substitutes, authorization thereof
15123 Whether to authorize the substitute keys listed in
15124 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
15125 (@pxref{Substitutes}).
15127 When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
15128 changed by invoking @command{guix archive --authorize}. You must
15129 instead adjust @code{guix-configuration} as you wish and reconfigure the
15130 system. This ensures that your operating system configuration file is
15134 When booting or reconfiguring to a system where @code{authorize-key?}
15135 is true, the existing @file{/etc/guix/acl} file is backed up as
15136 @file{/etc/guix/acl.bak} if it was determined to be a manually modified
15137 file. This is to facilitate migration from earlier versions, which
15138 allowed for in-place modifications to @file{/etc/guix/acl}.
15141 @vindex %default-authorized-guix-keys
15142 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
15143 The list of authorized key files for archive imports, as a list of
15144 string-valued gexps (@pxref{Invoking guix archive}). By default, it
15145 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
15146 See @code{substitute-urls} below for an example on how to change it.
15148 @item @code{use-substitutes?} (default: @code{#t})
15149 Whether to use substitutes.
15151 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
15152 The list of URLs where to look for substitutes by default.
15154 Suppose you would like to fetch substitutes from @code{guix.example.org}
15155 in addition to @code{@value{SUBSTITUTE-SERVER}}. You will need to do
15156 two things: (1) add @code{guix.example.org} to @code{substitute-urls},
15157 and (2) authorize its signing key, having done appropriate checks
15158 (@pxref{Substitute Server Authorization}). The configuration below does
15162 (guix-configuration
15164 (append (list "https://guix.example.org")
15165 %default-substitute-urls))
15167 (append (list (local-file "./guix.example.org-key.pub"))
15168 %default-authorized-guix-keys)))
15171 This example assumes that the file @file{./guix.example.org-key.pub}
15172 contains the public key that @code{guix.example.org} uses to sign
15175 @item @code{max-silent-time} (default: @code{0})
15176 @itemx @code{timeout} (default: @code{0})
15177 The number of seconds of silence and the number of seconds of activity,
15178 respectively, after which a build process times out. A value of zero
15179 disables the timeout.
15181 @item @code{log-compression} (default: @code{'bzip2})
15182 The type of compression used for build logs---one of @code{gzip},
15183 @code{bzip2}, or @code{none}.
15185 @item @code{discover?} (default: @code{#f})
15186 Whether to discover substitute servers on the local network using mDNS
15189 @item @code{extra-options} (default: @code{'()})
15190 List of extra command-line options for @command{guix-daemon}.
15192 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
15193 File where @command{guix-daemon}'s standard output and standard error
15196 @cindex HTTP proxy, for @code{guix-daemon}
15197 @cindex proxy, for @code{guix-daemon} HTTP access
15198 @item @code{http-proxy} (default: @code{#f})
15199 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
15200 derivations and substitutes.
15202 It is also possible to change the daemon's proxy at run time through the
15203 @code{set-http-proxy} action, which restarts it:
15206 herd set-http-proxy guix-daemon http://localhost:8118
15209 To clear the proxy settings, run:
15212 herd set-http-proxy guix-daemon
15215 @item @code{tmpdir} (default: @code{#f})
15216 A directory path where the @command{guix-daemon} will perform builds.
15221 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
15222 Run @var{udev}, which populates the @file{/dev} directory dynamically.
15223 udev rules can be provided as a list of files through the @var{rules}
15224 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
15225 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
15226 creation of such rule files.
15228 The @command{herd rules udev} command, as root, returns the name of the
15229 directory containing all the active udev rules.
15232 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
15233 Return a udev-rule file named @var{file-name} containing the rules
15234 defined by the @var{contents} literal.
15236 In the following example, a rule for a USB device is defined to be
15237 stored in the file @file{90-usb-thing.rules}. The rule runs a script
15238 upon detecting a USB device with a given product identifier.
15241 (define %example-udev-rule
15243 "90-usb-thing.rules"
15244 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
15245 "ATTR@{product@}==\"Example\", "
15246 "RUN+=\"/path/to/script\"")))
15250 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
15251 [#:groups @var{groups}]
15252 Return a service that extends @code{udev-service-type } with @var{rules}
15253 and @code{account-service-type} with @var{groups} as system groups.
15254 This works by creating a singleton service type
15255 @code{@var{name}-udev-rules}, of which the returned service is an
15258 Here we show how it can be used to extend @code{udev-service-type} with the
15259 previously defined rule @code{%example-udev-rule}.
15265 (cons (udev-rules-service 'usb-thing %example-udev-rule)
15266 %desktop-services)))
15270 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
15271 Return a udev file named @var{file-name} containing the rules defined
15272 within @var{file}, a file-like object.
15274 The following example showcases how we can use an existing rule file.
15277 (use-modules (guix download) ;for url-fetch
15278 (guix packages) ;for origin
15281 (define %android-udev-rules
15283 "51-android-udev.rules"
15284 (let ((version "20170910"))
15287 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
15288 "android-udev-rules/" version "/51-android.rules"))
15290 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
15294 Additionally, Guix package definitions can be included in @var{rules} in
15295 order to extend the udev rules with the definitions found under their
15296 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
15297 @var{file->udev-rule} example, we could have used the
15298 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
15299 packages android)} module.
15301 The following example shows how to use the @var{android-udev-rules}
15302 package so that the Android tool @command{adb} can detect devices
15303 without root privileges. It also details how to create the
15304 @code{adbusers} group, which is required for the proper functioning of
15305 the rules defined within the @code{android-udev-rules} package. To
15306 create such a group, we must define it both as part of the
15307 @code{supplementary-groups} of our @code{user-account} declaration, as
15308 well as in the @var{groups} of the @code{udev-rules-service} procedure.
15311 (use-modules (gnu packages android) ;for android-udev-rules
15312 (gnu system shadow) ;for user-group
15317 (users (cons (user-account
15319 (supplementary-groups
15320 '("adbusers" ;for adb
15321 "wheel" "netdev" "audio" "video")))))
15324 (cons (udev-rules-service 'android android-udev-rules
15325 #:groups '("adbusers"))
15326 %desktop-services)))
15329 @defvr {Scheme Variable} urandom-seed-service-type
15330 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
15331 when rebooting. It also tries to seed @file{/dev/urandom} from
15332 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
15336 @defvr {Scheme Variable} %random-seed-file
15337 This is the name of the file where some random bytes are saved by
15338 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
15339 It defaults to @file{/var/lib/random-seed}.
15344 @defvr {Scheme Variable} gpm-service-type
15345 This is the type of the service that runs GPM, the @dfn{general-purpose
15346 mouse daemon}, which provides mouse support to the Linux console. GPM
15347 allows users to use the mouse in the console, notably to select, copy,
15350 The value for services of this type must be a @code{gpm-configuration}
15351 (see below). This service is not part of @code{%base-services}.
15354 @deftp {Data Type} gpm-configuration
15355 Data type representing the configuration of GPM.
15358 @item @code{options} (default: @code{%default-gpm-options})
15359 Command-line options passed to @command{gpm}. The default set of
15360 options instruct @command{gpm} to listen to mouse events on
15361 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
15364 @item @code{gpm} (default: @code{gpm})
15365 The GPM package to use.
15370 @anchor{guix-publish-service-type}
15371 @deffn {Scheme Variable} guix-publish-service-type
15372 This is the service type for @command{guix publish} (@pxref{Invoking
15373 guix publish}). Its value must be a @code{guix-publish-configuration}
15374 object, as described below.
15376 This assumes that @file{/etc/guix} already contains a signing key pair as
15377 created by @command{guix archive --generate-key} (@pxref{Invoking guix
15378 archive}). If that is not the case, the service will fail to start.
15381 @deftp {Data Type} guix-publish-configuration
15382 Data type representing the configuration of the @code{guix publish}
15386 @item @code{guix} (default: @code{guix})
15387 The Guix package to use.
15389 @item @code{port} (default: @code{80})
15390 The TCP port to listen for connections.
15392 @item @code{host} (default: @code{"localhost"})
15393 The host (and thus, network interface) to listen to. Use
15394 @code{"0.0.0.0"} to listen on all the network interfaces.
15396 @item @code{advertise?} (default: @code{#f})
15397 When true, advertise the service on the local network @i{via} the DNS-SD
15398 protocol, using Avahi.
15400 This allows neighboring Guix devices with discovery on (see
15401 @code{guix-configuration} above) to discover this @command{guix publish}
15402 instance and to automatically download substitutes from it.
15404 @item @code{compression} (default: @code{'(("gzip" 3))})
15405 This is a list of compression method/level tuple used when compressing
15406 substitutes. For example, to compress all substitutes with @emph{both} lzip
15407 at level 7 and gzip at level 9, write:
15410 '(("lzip" 7) ("gzip" 9))
15413 Level 9 achieves the best compression ratio at the expense of increased CPU
15414 usage, whereas level 1 achieves fast compression. @xref{Invoking guix
15415 publish}, for more information on the available compression methods and
15416 the tradeoffs involved.
15418 An empty list disables compression altogether.
15420 @item @code{nar-path} (default: @code{"nar"})
15421 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
15422 publish, @option{--nar-path}}, for details.
15424 @item @code{cache} (default: @code{#f})
15425 When it is @code{#f}, disable caching and instead generate archives on
15426 demand. Otherwise, this should be the name of a directory---e.g.,
15427 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
15428 archives and meta-data ready to be sent. @xref{Invoking guix publish,
15429 @option{--cache}}, for more information on the tradeoffs involved.
15431 @item @code{workers} (default: @code{#f})
15432 When it is an integer, this is the number of worker threads used for
15433 caching; when @code{#f}, the number of processors is used.
15434 @xref{Invoking guix publish, @option{--workers}}, for more information.
15436 @item @code{cache-bypass-threshold} (default: 10 MiB)
15437 When @code{cache} is true, this is the maximum size in bytes of a store
15438 item for which @command{guix publish} may bypass its cache in case of a
15439 cache miss. @xref{Invoking guix publish,
15440 @option{--cache-bypass-threshold}}, for more information.
15442 @item @code{ttl} (default: @code{#f})
15443 When it is an integer, this denotes the @dfn{time-to-live} in seconds
15444 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
15445 for more information.
15449 @anchor{rngd-service}
15450 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
15451 [#:device "/dev/hwrng"]
15452 Return a service that runs the @command{rngd} program from @var{rng-tools}
15453 to add @var{device} to the kernel's entropy pool. The service will fail if
15454 @var{device} does not exist.
15457 @anchor{pam-limits-service}
15458 @cindex session limits
15463 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
15465 Return a service that installs a configuration file for the
15466 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
15467 @code{pam_limits} module}. The procedure optionally takes a list of
15468 @code{pam-limits-entry} values, which can be used to specify
15469 @code{ulimit} limits and nice priority limits to user sessions.
15471 The following limits definition sets two hard and soft limits for all
15472 login sessions of users in the @code{realtime} group:
15475 (pam-limits-service
15477 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
15478 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
15481 The first entry increases the maximum realtime priority for
15482 non-privileged processes; the second entry lifts any restriction of the
15483 maximum address space that can be locked in memory. These settings are
15484 commonly used for real-time audio systems.
15487 @node Scheduled Job Execution
15488 @subsection Scheduled Job Execution
15492 @cindex scheduling jobs
15493 The @code{(gnu services mcron)} module provides an interface to
15494 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
15495 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
15496 Unix @command{cron} daemon; the main difference is that it is
15497 implemented in Guile Scheme, which provides a lot of flexibility when
15498 specifying the scheduling of jobs and their actions.
15500 The example below defines an operating system that runs the
15501 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
15502 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
15503 well as the @command{mkid} command on behalf of an unprivileged user
15504 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
15505 gexps to introduce job definitions that are passed to mcron
15506 (@pxref{G-Expressions}).
15509 (use-modules (guix) (gnu) (gnu services mcron))
15510 (use-package-modules base idutils)
15512 (define updatedb-job
15513 ;; Run 'updatedb' at 3AM every day. Here we write the
15514 ;; job's action as a Scheme procedure.
15515 #~(job '(next-hour '(3))
15517 (execl (string-append #$findutils "/bin/updatedb")
15519 "--prunepaths=/tmp /var/tmp /gnu/store"))))
15521 (define garbage-collector-job
15522 ;; Collect garbage 5 minutes after midnight every day.
15523 ;; The job's action is a shell command.
15524 #~(job "5 0 * * *" ;Vixie cron syntax
15527 (define idutils-job
15528 ;; Update the index database as user "charlie" at 12:15PM
15529 ;; and 19:15PM. This runs from the user's home directory.
15530 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
15531 (string-append #$idutils "/bin/mkid src")
15537 ;; %BASE-SERVICES already includes an instance of
15538 ;; 'mcron-service-type', which we extend with additional
15539 ;; jobs using 'simple-service'.
15540 (services (cons (simple-service 'my-cron-jobs
15542 (list garbage-collector-job
15548 For more complex jobs defined in Scheme where you need control over the top
15549 level, for instance to introduce a @code{use-modules} form, you can move your
15550 code to a separate program using the @code{program-file} procedure of the
15551 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
15555 (define %battery-alert-job
15556 ;; Beep when the battery percentage falls below %MIN-LEVEL.
15558 '(next-minute (range 0 60 1))
15560 "battery-alert.scm"
15561 (with-imported-modules (source-module-closure
15562 '((guix build utils)))
15564 (use-modules (guix build utils)
15567 (ice-9 textual-ports)
15570 (define %min-level 20)
15572 (setenv "LC_ALL" "C") ;ensure English output
15573 (and-let* ((input-pipe (open-pipe*
15575 #$(file-append acpi "/bin/acpi")))
15576 (output (get-string-all input-pipe))
15577 (m (string-match "Discharging, ([0-9]+)%" output))
15578 (level (string->number (match:substring m 1)))
15579 ((< level %min-level)))
15580 (format #t "warning: Battery level is low (~a%)~%" level)
15581 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
15584 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
15585 for more information on mcron job specifications. Below is the
15586 reference of the mcron service.
15588 On a running system, you can use the @code{schedule} action of the service to
15589 visualize the mcron jobs that will be executed next:
15592 # herd schedule mcron
15596 The example above lists the next five tasks that will be executed, but you can
15597 also specify the number of tasks to display:
15600 # herd schedule mcron 10
15603 @defvr {Scheme Variable} mcron-service-type
15604 This is the type of the @code{mcron} service, whose value is an
15605 @code{mcron-configuration} object.
15607 This service type can be the target of a service extension that provides
15608 it additional job specifications (@pxref{Service Composition}). In
15609 other words, it is possible to define services that provide additional
15613 @deftp {Data Type} mcron-configuration
15614 Data type representing the configuration of mcron.
15617 @item @code{mcron} (default: @var{mcron})
15618 The mcron package to use.
15621 This is a list of gexps (@pxref{G-Expressions}), where each gexp
15622 corresponds to an mcron job specification (@pxref{Syntax, mcron job
15623 specifications,, mcron, GNU@tie{}mcron}).
15629 @subsection Log Rotation
15632 @cindex log rotation
15634 Log files such as those found in @file{/var/log} tend to grow endlessly,
15635 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
15636 their contents in separate files, possibly compressed. The @code{(gnu
15637 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
15638 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
15640 This service is part of @code{%base-services}, and thus enabled by
15641 default, with the default settings, for commonly encountered log files.
15642 The example below shows how to extend it with an additional
15643 @dfn{rotation}, should you need to do that (usually, services that
15644 produce log files already take care of that):
15647 (use-modules (guix) (gnu))
15648 (use-service-modules admin)
15650 (define my-log-files
15651 ;; Log files that I want to rotate.
15652 '("/var/log/something.log" "/var/log/another.log"))
15656 (services (cons (simple-service 'rotate-my-stuff
15657 rottlog-service-type
15658 (list (log-rotation
15660 (files my-log-files))))
15664 @defvr {Scheme Variable} rottlog-service-type
15665 This is the type of the Rottlog service, whose value is a
15666 @code{rottlog-configuration} object.
15668 Other services can extend this one with new @code{log-rotation} objects
15669 (see below), thereby augmenting the set of files to be rotated.
15671 This service type can define mcron jobs (@pxref{Scheduled Job
15672 Execution}) to run the rottlog service.
15675 @deftp {Data Type} rottlog-configuration
15676 Data type representing the configuration of rottlog.
15679 @item @code{rottlog} (default: @code{rottlog})
15680 The Rottlog package to use.
15682 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
15683 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
15684 rottlog, GNU Rot[t]log Manual}).
15686 @item @code{rotations} (default: @code{%default-rotations})
15687 A list of @code{log-rotation} objects as defined below.
15690 This is a list of gexps where each gexp corresponds to an mcron job
15691 specification (@pxref{Scheduled Job Execution}).
15695 @deftp {Data Type} log-rotation
15696 Data type representing the rotation of a group of log files.
15698 Taking an example from the Rottlog manual (@pxref{Period Related File
15699 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
15705 (files '("/var/log/apache/*"))
15706 (options '("storedir apache-archives"
15712 The list of fields is as follows:
15715 @item @code{frequency} (default: @code{'weekly})
15716 The log rotation frequency, a symbol.
15719 The list of files or file glob patterns to rotate.
15721 @item @code{options} (default: @code{'()})
15722 The list of rottlog options for this rotation (@pxref{Configuration
15723 parameters,,, rottlog, GNU Rot[t]lg Manual}).
15725 @item @code{post-rotate} (default: @code{#f})
15726 Either @code{#f} or a gexp to execute once the rotation has completed.
15730 @defvr {Scheme Variable} %default-rotations
15731 Specifies weekly rotation of @code{%rotated-files} and of
15732 @file{/var/log/guix-daemon.log}.
15735 @defvr {Scheme Variable} %rotated-files
15736 The list of syslog-controlled files to be rotated. By default it is:
15737 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
15738 "/var/log/maillog")}.
15741 @node Networking Services
15742 @subsection Networking Services
15744 The @code{(gnu services networking)} module provides services to configure
15745 the network interface.
15747 @cindex DHCP, networking service
15748 @defvr {Scheme Variable} dhcp-client-service-type
15749 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
15750 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
15751 is the DHCP client package to use, @code{isc-dhcp} by default.
15754 @deffn {Scheme Procedure} dhcpd-service-type
15755 This type defines a service that runs a DHCP daemon. To create a
15756 service of this type, you must supply a @code{<dhcpd-configuration>}.
15760 (service dhcpd-service-type
15761 (dhcpd-configuration
15762 (config-file (local-file "my-dhcpd.conf"))
15763 (interfaces '("enp0s25"))))
15767 @deftp {Data Type} dhcpd-configuration
15769 @item @code{package} (default: @code{isc-dhcp})
15770 The package that provides the DHCP daemon. This package is expected to
15771 provide the daemon at @file{sbin/dhcpd} relative to its output
15772 directory. The default package is the
15773 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
15774 @item @code{config-file} (default: @code{#f})
15775 The configuration file to use. This is required. It will be passed to
15776 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
15777 object (@pxref{G-Expressions, file-like objects}). See @code{man
15778 dhcpd.conf} for details on the configuration file syntax.
15779 @item @code{version} (default: @code{"4"})
15780 The DHCP version to use. The ISC DHCP server supports the values ``4'',
15781 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
15782 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
15784 @item @code{run-directory} (default: @code{"/run/dhcpd"})
15785 The run directory to use. At service activation time, this directory
15786 will be created if it does not exist.
15787 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
15788 The PID file to use. This corresponds to the @code{-pf} option of
15789 @code{dhcpd}. See @code{man dhcpd} for details.
15790 @item @code{interfaces} (default: @code{'()})
15791 The names of the network interfaces on which dhcpd should listen for
15792 broadcasts. If this list is not empty, then its elements (which must be
15793 strings) will be appended to the @code{dhcpd} invocation when starting
15794 the daemon. It may not be necessary to explicitly specify any
15795 interfaces here; see @code{man dhcpd} for details.
15799 @defvr {Scheme Variable} static-networking-service-type
15800 This is the type for statically-configured network interfaces.
15801 @c TODO Document <static-networking> data structures.
15804 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
15805 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
15806 [#:requirement @code{'(udev)}]
15807 Return a service that starts @var{interface} with address @var{ip}. If
15808 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
15809 it must be a string specifying the default network gateway. @var{requirement}
15810 can be used to declare a dependency on another service before configuring the
15813 This procedure can be called several times, one for each network
15814 interface of interest. Behind the scenes what it does is extend
15815 @code{static-networking-service-type} with additional network interfaces
15821 (static-networking-service "eno1" "192.168.1.82"
15822 #:gateway "192.168.1.2"
15823 #:name-servers '("192.168.1.2"))
15830 @cindex network management
15831 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
15832 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
15833 management daemon that aims to simplify wired and wireless networking.
15835 This service adds the @var{wicd} package to the global profile, providing
15836 several commands to interact with the daemon and configure networking:
15837 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
15838 and @command{wicd-curses} user interfaces.
15841 @cindex ModemManager
15843 @defvr {Scheme Variable} modem-manager-service-type
15844 This is the service type for the
15845 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
15846 service. The value for this service type is a
15847 @code{modem-manager-configuration} record.
15849 This service is part of @code{%desktop-services} (@pxref{Desktop
15853 @deftp {Data Type} modem-manager-configuration
15854 Data type representing the configuration of ModemManager.
15857 @item @code{modem-manager} (default: @code{modem-manager})
15858 The ModemManager package to use.
15863 @cindex USB_ModeSwitch
15864 @cindex Modeswitching
15866 @defvr {Scheme Variable} usb-modeswitch-service-type
15867 This is the service type for the
15868 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch}
15869 service. The value for this service type is
15870 a @code{usb-modeswitch-configuration} record.
15872 When plugged in, some USB modems (and other USB devices) initially present
15873 themselves as a read-only storage medium and not as a modem. They need to be
15874 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
15875 installs udev rules to automatically modeswitch these devices when they are
15878 This service is part of @code{%desktop-services} (@pxref{Desktop
15882 @deftp {Data Type} usb-modeswitch-configuration
15883 Data type representing the configuration of USB_ModeSwitch.
15886 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
15887 The USB_ModeSwitch package providing the binaries for modeswitching.
15889 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
15890 The package providing the device data and udev rules file used by
15893 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
15894 Which config file to use for the USB_ModeSwitch dispatcher. By default the
15895 config file shipped with USB_ModeSwitch is used which disables logging to
15896 @file{/var/log} among other default settings. If set to @code{#f}, no config
15902 @cindex NetworkManager
15904 @defvr {Scheme Variable} network-manager-service-type
15905 This is the service type for the
15906 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
15907 service. The value for this service type is a
15908 @code{network-manager-configuration} record.
15910 This service is part of @code{%desktop-services} (@pxref{Desktop
15914 @deftp {Data Type} network-manager-configuration
15915 Data type representing the configuration of NetworkManager.
15918 @item @code{network-manager} (default: @code{network-manager})
15919 The NetworkManager package to use.
15921 @item @code{dns} (default: @code{"default"})
15922 Processing mode for DNS, which affects how NetworkManager uses the
15923 @code{resolv.conf} configuration file.
15927 NetworkManager will update @code{resolv.conf} to reflect the nameservers
15928 provided by currently active connections.
15931 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
15932 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
15933 then update @code{resolv.conf} to point to the local nameserver.
15935 With this setting, you can share your network connection. For example when
15936 you want to share your network connection to another laptop @i{via} an
15937 Ethernet cable, you can open @command{nm-connection-editor} and configure the
15938 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
15939 and reestablish the connection (or reboot).
15941 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
15942 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
15943 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
15944 browser on your host system, or connect to the VM @i{via} SSH
15945 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
15946 host-to-guest connection, run this command once:
15949 nmcli connection add type tun \
15950 connection.interface-name tap0 \
15951 tun.mode tap tun.owner $(id -u) \
15952 ipv4.method shared \
15953 ipv4.addresses 172.28.112.1/24
15956 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
15957 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
15958 @command{qemu-system-...}.
15961 NetworkManager will not modify @code{resolv.conf}.
15964 @item @code{vpn-plugins} (default: @code{'()})
15965 This is the list of available plugins for virtual private networks
15966 (VPNs). An example of this is the @code{network-manager-openvpn}
15967 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
15973 @deffn {Scheme Variable} connman-service-type
15974 This is the service type to run @url{https://01.org/connman,Connman},
15975 a network connection manager.
15977 Its value must be an
15978 @code{connman-configuration} record as in this example:
15981 (service connman-service-type
15982 (connman-configuration
15983 (disable-vpn? #t)))
15986 See below for details about @code{connman-configuration}.
15989 @deftp {Data Type} connman-configuration
15990 Data Type representing the configuration of connman.
15993 @item @code{connman} (default: @var{connman})
15994 The connman package to use.
15996 @item @code{disable-vpn?} (default: @code{#f})
15997 When true, disable connman's vpn plugin.
16001 @cindex WPA Supplicant
16002 @defvr {Scheme Variable} wpa-supplicant-service-type
16003 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
16004 supplicant}, an authentication daemon required to authenticate against
16005 encrypted WiFi or ethernet networks.
16008 @deftp {Data Type} wpa-supplicant-configuration
16009 Data type representing the configuration of WPA Supplicant.
16011 It takes the following parameters:
16014 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
16015 The WPA Supplicant package to use.
16017 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
16018 List of services that should be started before WPA Supplicant starts.
16020 @item @code{dbus?} (default: @code{#t})
16021 Whether to listen for requests on D-Bus.
16023 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
16024 Where to store the PID file.
16026 @item @code{interface} (default: @code{#f})
16027 If this is set, it must specify the name of a network interface that
16028 WPA supplicant will control.
16030 @item @code{config-file} (default: @code{#f})
16031 Optional configuration file to use.
16033 @item @code{extra-options} (default: @code{'()})
16034 List of additional command-line arguments to pass to the daemon.
16038 @cindex hostapd service, for Wi-Fi access points
16039 @cindex Wi-Fi access points, hostapd service
16040 @defvr {Scheme Variable} hostapd-service-type
16041 This is the service type to run the @uref{https://w1.fi/hostapd/,
16042 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
16043 authentication servers. Its associated value must be a
16044 @code{hostapd-configuration} as shown below:
16047 ;; Use wlan1 to run the access point for "My Network".
16048 (service hostapd-service-type
16049 (hostapd-configuration
16050 (interface "wlan1")
16051 (ssid "My Network")
16056 @deftp {Data Type} hostapd-configuration
16057 This data type represents the configuration of the hostapd service, with
16058 the following fields:
16061 @item @code{package} (default: @code{hostapd})
16062 The hostapd package to use.
16064 @item @code{interface} (default: @code{"wlan0"})
16065 The network interface to run the WiFi access point.
16068 The SSID (@dfn{service set identifier}), a string that identifies this
16071 @item @code{broadcast-ssid?} (default: @code{#t})
16072 Whether to broadcast this SSID.
16074 @item @code{channel} (default: @code{1})
16075 The WiFi channel to use.
16077 @item @code{driver} (default: @code{"nl80211"})
16078 The driver interface type. @code{"nl80211"} is used with all Linux
16079 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
16080 RADIUS server that does # not control any wireless/wired driver.
16082 @item @code{extra-settings} (default: @code{""})
16083 Extra settings to append as-is to the hostapd configuration file. See
16084 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
16085 configuration file reference.
16089 @defvr {Scheme Variable} simulated-wifi-service-type
16090 This is the type of a service to simulate WiFi networking, which can be
16091 useful in virtual machines for testing purposes. The service loads the
16093 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
16094 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
16095 network that can be seen on @code{wlan0}, by default.
16097 The service's value is a @code{hostapd-configuration} record.
16101 @defvr {Scheme Variable} iptables-service-type
16102 This is the service type to set up an iptables configuration. iptables is a
16103 packet filtering framework supported by the Linux kernel. This service
16104 supports configuring iptables for both IPv4 and IPv6. A simple example
16105 configuration rejecting all incoming connections except those to the ssh port
16109 (service iptables-service-type
16110 (iptables-configuration
16111 (ipv4-rules (plain-file "iptables.rules" "*filter
16115 -A INPUT -p tcp --dport 22 -j ACCEPT
16116 -A INPUT -j REJECT --reject-with icmp-port-unreachable
16119 (ipv6-rules (plain-file "ip6tables.rules" "*filter
16123 -A INPUT -p tcp --dport 22 -j ACCEPT
16124 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
16130 @deftp {Data Type} iptables-configuration
16131 The data type representing the configuration of iptables.
16134 @item @code{iptables} (default: @code{iptables})
16135 The iptables package that provides @code{iptables-restore} and
16136 @code{ip6tables-restore}.
16137 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
16138 The iptables rules to use. It will be passed to @code{iptables-restore}.
16139 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16141 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
16142 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
16143 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16149 @defvr {Scheme Variable} nftables-service-type
16150 This is the service type to set up a nftables configuration. nftables is a
16151 netfilter project that aims to replace the existing iptables, ip6tables,
16152 arptables and ebtables framework. It provides a new packet filtering
16153 framework, a new user-space utility @command{nft}, and a compatibility layer
16154 for iptables. This service comes with a default ruleset
16155 @code{%default-nftables-ruleset} that rejecting all incomming connections
16156 except those to the ssh port 22. To use it, simply write:
16159 (service nftables-service-type)
16163 @deftp {Data Type} nftables-configuration
16164 The data type representing the configuration of nftables.
16167 @item @code{package} (default: @code{nftables})
16168 The nftables package that provides @command{nft}.
16169 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
16170 The nftables ruleset to use. This may be any ``file-like'' object
16171 (@pxref{G-Expressions, file-like objects}).
16175 @cindex NTP (Network Time Protocol), service
16176 @cindex ntpd, service for the Network Time Protocol daemon
16177 @cindex real time clock
16178 @defvr {Scheme Variable} ntp-service-type
16179 This is the type of the service running the @uref{https://www.ntp.org,
16180 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
16181 system clock synchronized with that of the specified NTP servers.
16183 The value of this service is an @code{ntpd-configuration} object, as described
16187 @deftp {Data Type} ntp-configuration
16188 This is the data type for the NTP service configuration.
16191 @item @code{servers} (default: @code{%ntp-servers})
16192 This is the list of servers (@code{<ntp-server>} records) with which
16193 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
16196 @item @code{allow-large-adjustment?} (default: @code{#t})
16197 This determines whether @command{ntpd} is allowed to make an initial
16198 adjustment of more than 1,000 seconds.
16200 @item @code{ntp} (default: @code{ntp})
16201 The NTP package to use.
16205 @defvr {Scheme Variable} %ntp-servers
16206 List of host names used as the default NTP servers. These are servers of the
16207 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
16210 @deftp {Data Type} ntp-server
16211 The data type representing the configuration of a NTP server.
16214 @item @code{type} (default: @code{'server})
16215 The type of the NTP server, given as a symbol. One of @code{'pool},
16216 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
16218 @item @code{address}
16219 The address of the server, as a string.
16221 @item @code{options}
16222 NTPD options to use with that specific server, given as a list of option names
16223 and/or of option names and values tuples. The following example define a server
16224 to use with the options @option{iburst} and @option{prefer}, as well as
16225 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
16230 (address "some.ntp.server.org")
16231 (options `(iburst (version 3) (maxpoll 16) prefer))))
16237 @deffn {Scheme Procedure} openntpd-service-type
16238 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
16239 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
16240 clock synchronized with that of the given servers.
16244 openntpd-service-type
16245 (openntpd-configuration
16246 (listen-on '("127.0.0.1" "::1"))
16247 (sensor '("udcf0 correction 70000"))
16248 (constraint-from '("www.gnu.org"))
16249 (constraints-from '("https://www.google.com/"))))
16254 @defvr {Scheme Variable} %openntpd-servers
16255 This variable is a list of the server addresses defined in
16256 @code{%ntp-servers}.
16259 @deftp {Data Type} openntpd-configuration
16261 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
16262 The openntpd executable to use.
16263 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
16264 A list of local IP addresses or hostnames the ntpd daemon should listen on.
16265 @item @code{query-from} (default: @code{'()})
16266 A list of local IP address the ntpd daemon should use for outgoing queries.
16267 @item @code{sensor} (default: @code{'()})
16268 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
16269 will listen to each sensor that actually exists and ignore non-existent ones.
16270 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
16272 @item @code{server} (default: @code{'()})
16273 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
16274 @item @code{servers} (default: @code{%openntp-servers})
16275 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
16276 @item @code{constraint-from} (default: @code{'()})
16277 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
16278 This time information is not used for precision but acts as an authenticated
16279 constraint, thereby reducing the impact of unauthenticated NTP
16280 man-in-the-middle attacks.
16281 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
16283 @item @code{constraints-from} (default: @code{'()})
16284 As with constraint from, specify a list of URLs, IP addresses or hostnames of
16285 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
16286 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
16291 @deffn {Scheme variable} inetd-service-type
16292 This service runs the @command{inetd} (@pxref{inetd invocation,,,
16293 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
16294 connections on internet sockets, and lazily starts the specified server
16295 program when a connection is made on one of these sockets.
16297 The value of this service is an @code{inetd-configuration} object. The
16298 following example configures the @command{inetd} daemon to provide the
16299 built-in @command{echo} service, as well as an smtp service which
16300 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
16301 gateway @code{hostname}:
16306 (inetd-configuration
16310 (socket-type 'stream)
16317 (socket-type 'stream)
16321 (program (file-append openssh "/bin/ssh"))
16323 '("ssh" "-qT" "-i" "/path/to/ssh_key"
16324 "-W" "smtp-server:25" "user@@hostname")))))))
16327 See below for more details about @code{inetd-configuration}.
16330 @deftp {Data Type} inetd-configuration
16331 Data type representing the configuration of @command{inetd}.
16334 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
16335 The @command{inetd} executable to use.
16337 @item @code{entries} (default: @code{'()})
16338 A list of @command{inetd} service entries. Each entry should be created
16339 by the @code{inetd-entry} constructor.
16343 @deftp {Data Type} inetd-entry
16344 Data type representing an entry in the @command{inetd} configuration.
16345 Each entry corresponds to a socket where @command{inetd} will listen for
16349 @item @code{node} (default: @code{#f})
16350 Optional string, a comma-separated list of local addresses
16351 @command{inetd} should use when listening for this service.
16352 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
16353 description of all options.
16355 A string, the name must correspond to an entry in @code{/etc/services}.
16356 @item @code{socket-type}
16357 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
16359 @item @code{protocol}
16360 A string, must correspond to an entry in @code{/etc/protocols}.
16361 @item @code{wait?} (default: @code{#t})
16362 Whether @command{inetd} should wait for the server to exit before
16363 listening to new service requests.
16365 A string containing the user (and, optionally, group) name of the user
16366 as whom the server should run. The group name can be specified in a
16367 suffix, separated by a colon or period, i.e.@: @code{"user"},
16368 @code{"user:group"} or @code{"user.group"}.
16369 @item @code{program} (default: @code{"internal"})
16370 The server program which will serve the requests, or @code{"internal"}
16371 if @command{inetd} should use a built-in service.
16372 @item @code{arguments} (default: @code{'()})
16373 A list strings or file-like objects, which are the server program's
16374 arguments, starting with the zeroth argument, i.e.@: the name of the
16375 program itself. For @command{inetd}'s internal services, this entry
16376 must be @code{'()} or @code{'("internal")}.
16379 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
16380 detailed discussion of each configuration field.
16384 @defvr {Scheme Variable} tor-service-type
16385 This is the type for a service that runs the @uref{https://torproject.org,
16386 Tor} anonymous networking daemon. The service is configured using a
16387 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
16388 @code{tor} unprivileged user, which is a member of the @code{tor} group.
16392 @deftp {Data Type} tor-configuration
16394 @item @code{tor} (default: @code{tor})
16395 The package that provides the Tor daemon. This package is expected to provide
16396 the daemon at @file{bin/tor} relative to its output directory. The default
16397 package is the @uref{https://www.torproject.org, Tor Project's}
16400 @item @code{config-file} (default: @code{(plain-file "empty" "")})
16401 The configuration file to use. It will be appended to a default configuration
16402 file, and the final configuration file will be passed to @code{tor} via its
16403 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
16404 file-like objects}). See @code{man tor} for details on the configuration file
16407 @item @code{hidden-services} (default: @code{'()})
16408 The list of @code{<hidden-service>} records to use. For any hidden service
16409 you include in this list, appropriate configuration to enable the hidden
16410 service will be automatically added to the default configuration file. You
16411 may conveniently create @code{<hidden-service>} records using the
16412 @code{tor-hidden-service} procedure described below.
16414 @item @code{socks-socket-type} (default: @code{'tcp})
16415 The default socket type that Tor should use for its SOCKS socket. This must
16416 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
16417 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
16418 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
16419 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
16422 If you want to customize the SOCKS socket in more detail, leave
16423 @code{socks-socket-type} at its default value of @code{'tcp} and use
16424 @code{config-file} to override the default by providing your own
16425 @code{SocksPort} option.
16429 @cindex hidden service
16430 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
16431 Define a new Tor @dfn{hidden service} called @var{name} and implementing
16432 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
16435 '((22 "127.0.0.1:22")
16436 (80 "127.0.0.1:8080"))
16439 In this example, port 22 of the hidden service is mapped to local port 22, and
16440 port 80 is mapped to local port 8080.
16442 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
16443 the @file{hostname} file contains the @code{.onion} host name for the hidden
16446 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
16447 project's documentation} for more information.
16450 The @code{(gnu services rsync)} module provides the following services:
16452 You might want an rsync daemon if you have files that you want available
16453 so anyone (or just yourself) can download existing files or upload new
16456 @deffn {Scheme Variable} rsync-service-type
16457 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
16458 The value for this service type is a
16459 @command{rsync-configuration} record as in this example:
16462 (service rsync-service-type)
16465 See below for details about @code{rsync-configuration}.
16468 @deftp {Data Type} rsync-configuration
16469 Data type representing the configuration for @code{rsync-service}.
16472 @item @code{package} (default: @var{rsync})
16473 @code{rsync} package to use.
16475 @item @code{port-number} (default: @code{873})
16476 TCP port on which @command{rsync} listens for incoming connections. If port
16477 is less than @code{1024} @command{rsync} needs to be started as the
16478 @code{root} user and group.
16480 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
16481 Name of the file where @command{rsync} writes its PID.
16483 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
16484 Name of the file where @command{rsync} writes its lock file.
16486 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
16487 Name of the file where @command{rsync} writes its log file.
16489 @item @code{use-chroot?} (default: @var{#t})
16490 Whether to use chroot for @command{rsync} shared directory.
16492 @item @code{share-path} (default: @file{/srv/rsync})
16493 Location of the @command{rsync} shared directory.
16495 @item @code{share-comment} (default: @code{"Rsync share"})
16496 Comment of the @command{rsync} shared directory.
16498 @item @code{read-only?} (default: @var{#f})
16499 Read-write permissions to shared directory.
16501 @item @code{timeout} (default: @code{300})
16502 I/O timeout in seconds.
16504 @item @code{user} (default: @var{"root"})
16505 Owner of the @code{rsync} process.
16507 @item @code{group} (default: @var{"root"})
16508 Group of the @code{rsync} process.
16510 @item @code{uid} (default: @var{"rsyncd"})
16511 User name or user ID that file transfers to and from that module should take
16512 place as when the daemon was run as @code{root}.
16514 @item @code{gid} (default: @var{"rsyncd"})
16515 Group name or group ID that will be used when accessing the module.
16520 The @code{(gnu services syncthing)} module provides the following services:
16523 You might want a syncthing daemon if you have files between two or more
16524 computers and want to sync them in real time, safely protected from
16527 @deffn {Scheme Variable} syncthing-service-type
16528 This is the service type for the @uref{https://syncthing.net/,
16529 syncthing} daemon, The value for this service type is a
16530 @command{syncthing-configuration} record as in this example:
16533 (service syncthing-service-type
16534 (syncthing-configuration (user "alice")))
16537 See below for details about @code{syncthing-configuration}.
16539 @deftp {Data Type} syncthing-configuration
16540 Data type representing the configuration for @code{syncthing-service-type}.
16543 @item @code{syncthing} (default: @var{syncthing})
16544 @code{syncthing} package to use.
16546 @item @code{arguments} (default: @var{'()})
16547 List of command-line arguments passing to @code{syncthing} binary.
16549 @item @code{logflags} (default: @var{0})
16550 Sum of loging flags, see
16551 @uref{https://docs.syncthing.net/users/syncthing.html#cmdoption-logflags, Syncthing documentation logflags}.
16553 @item @code{user} (default: @var{#f})
16554 The user as which the Syncthing service is to be run.
16555 This assumes that the specified user exists.
16557 @item @code{group} (default: @var{"users"})
16558 The group as which the Syncthing service is to be run.
16559 This assumes that the specified group exists.
16561 @item @code{home} (default: @var{#f})
16562 Common configuration and data directory. The default configuration
16563 directory is @file{$HOME} of the specified Syncthing @code{user}.
16569 Furthermore, @code{(gnu services ssh)} provides the following services.
16573 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
16574 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
16575 [#:allow-empty-passwords? #f] [#:root-login? #f] @
16576 [#:syslog-output? #t] [#:x11-forwarding? #t] @
16577 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
16578 [#:public-key-authentication? #t] [#:initialize? #t]
16579 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
16580 @var{host-key} must designate a file containing the host key, and readable
16583 When @var{daemonic?} is true, @command{lshd} will detach from the
16584 controlling terminal and log its output to syslogd, unless one sets
16585 @var{syslog-output?} to false. Obviously, it also makes lsh-service
16586 depend on existence of syslogd service. When @var{pid-file?} is true,
16587 @command{lshd} writes its PID to the file called @var{pid-file}.
16589 When @var{initialize?} is true, automatically create the seed and host key
16590 upon service activation if they do not exist yet. This may take long and
16591 require interaction.
16593 When @var{initialize?} is false, it is up to the user to initialize the
16594 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
16595 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
16596 basics,,, lsh, LSH Manual}).
16598 When @var{interfaces} is empty, lshd listens for connections on all the
16599 network interfaces; otherwise, @var{interfaces} must be a list of host names
16602 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
16603 passwords, and @var{root-login?} specifies whether to accept log-ins as
16606 The other options should be self-descriptive.
16611 @deffn {Scheme Variable} openssh-service-type
16612 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
16613 shell daemon, @command{sshd}. Its value must be an
16614 @code{openssh-configuration} record as in this example:
16617 (service openssh-service-type
16618 (openssh-configuration
16619 (x11-forwarding? #t)
16620 (permit-root-login 'without-password)
16622 `(("alice" ,(local-file "alice.pub"))
16623 ("bob" ,(local-file "bob.pub"))))))
16626 See below for details about @code{openssh-configuration}.
16628 This service can be extended with extra authorized keys, as in this
16632 (service-extension openssh-service-type
16633 (const `(("charlie"
16634 ,(local-file "charlie.pub")))))
16638 @deftp {Data Type} openssh-configuration
16639 This is the configuration record for OpenSSH's @command{sshd}.
16642 @item @code{openssh} (default @var{openssh})
16643 The Openssh package to use.
16645 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
16646 Name of the file where @command{sshd} writes its PID.
16648 @item @code{port-number} (default: @code{22})
16649 TCP port on which @command{sshd} listens for incoming connections.
16651 @item @code{permit-root-login} (default: @code{#f})
16652 This field determines whether and when to allow logins as root. If
16653 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
16654 If it's the symbol @code{'without-password}, then root logins are
16655 permitted but not with password-based authentication.
16657 @item @code{allow-empty-passwords?} (default: @code{#f})
16658 When true, users with empty passwords may log in. When false, they may
16661 @item @code{password-authentication?} (default: @code{#t})
16662 When true, users may log in with their password. When false, they have
16663 other authentication methods.
16665 @item @code{public-key-authentication?} (default: @code{#t})
16666 When true, users may log in using public key authentication. When
16667 false, users have to use other authentication method.
16669 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
16670 This is used only by protocol version 2.
16672 @item @code{x11-forwarding?} (default: @code{#f})
16673 When true, forwarding of X11 graphical client connections is
16674 enabled---in other words, @command{ssh} options @option{-X} and
16675 @option{-Y} will work.
16677 @item @code{allow-agent-forwarding?} (default: @code{#t})
16678 Whether to allow agent forwarding.
16680 @item @code{allow-tcp-forwarding?} (default: @code{#t})
16681 Whether to allow TCP forwarding.
16683 @item @code{gateway-ports?} (default: @code{#f})
16684 Whether to allow gateway ports.
16686 @item @code{challenge-response-authentication?} (default: @code{#f})
16687 Specifies whether challenge response authentication is allowed (e.g.@: via
16690 @item @code{use-pam?} (default: @code{#t})
16691 Enables the Pluggable Authentication Module interface. If set to
16692 @code{#t}, this will enable PAM authentication using
16693 @code{challenge-response-authentication?} and
16694 @code{password-authentication?}, in addition to PAM account and session
16695 module processing for all authentication types.
16697 Because PAM challenge response authentication usually serves an
16698 equivalent role to password authentication, you should disable either
16699 @code{challenge-response-authentication?} or
16700 @code{password-authentication?}.
16702 @item @code{print-last-log?} (default: @code{#t})
16703 Specifies whether @command{sshd} should print the date and time of the
16704 last user login when a user logs in interactively.
16706 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
16707 Configures external subsystems (e.g.@: file transfer daemon).
16709 This is a list of two-element lists, each of which containing the
16710 subsystem name and a command (with optional arguments) to execute upon
16713 The command @command{internal-sftp} implements an in-process SFTP
16714 server. Alternatively, one can specify the @command{sftp-server} command:
16716 (service openssh-service-type
16717 (openssh-configuration
16719 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
16722 @item @code{accepted-environment} (default: @code{'()})
16723 List of strings describing which environment variables may be exported.
16725 Each string gets on its own line. See the @code{AcceptEnv} option in
16726 @code{man sshd_config}.
16728 This example allows ssh-clients to export the @env{COLORTERM} variable.
16729 It is set by terminal emulators, which support colors. You can use it in
16730 your shell's resource file to enable colors for the prompt and commands
16731 if this variable is set.
16734 (service openssh-service-type
16735 (openssh-configuration
16736 (accepted-environment '("COLORTERM"))))
16739 @item @code{authorized-keys} (default: @code{'()})
16740 @cindex authorized keys, SSH
16741 @cindex SSH authorized keys
16742 This is the list of authorized keys. Each element of the list is a user
16743 name followed by one or more file-like objects that represent SSH public
16747 (openssh-configuration
16749 `(("rekado" ,(local-file "rekado.pub"))
16750 ("chris" ,(local-file "chris.pub"))
16751 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
16755 registers the specified public keys for user accounts @code{rekado},
16756 @code{chris}, and @code{root}.
16758 Additional authorized keys can be specified @i{via}
16759 @code{service-extension}.
16761 Note that this does @emph{not} interfere with the use of
16762 @file{~/.ssh/authorized_keys}.
16764 @item @code{log-level} (default: @code{'info})
16765 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
16766 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
16767 page for @file{sshd_config} for the full list of level names.
16769 @item @code{extra-content} (default: @code{""})
16770 This field can be used to append arbitrary text to the configuration file. It
16771 is especially useful for elaborate configurations that cannot be expressed
16772 otherwise. This configuration, for example, would generally disable root
16773 logins, but permit them from one specific IP address:
16776 (openssh-configuration
16778 Match Address 192.168.0.1
16779 PermitRootLogin yes"))
16785 @deffn {Scheme Procedure} dropbear-service [@var{config}]
16786 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
16787 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
16790 For example, to specify a Dropbear service listening on port 1234, add
16791 this call to the operating system's @code{services} field:
16794 (dropbear-service (dropbear-configuration
16795 (port-number 1234)))
16799 @deftp {Data Type} dropbear-configuration
16800 This data type represents the configuration of a Dropbear SSH daemon.
16803 @item @code{dropbear} (default: @var{dropbear})
16804 The Dropbear package to use.
16806 @item @code{port-number} (default: 22)
16807 The TCP port where the daemon waits for incoming connections.
16809 @item @code{syslog-output?} (default: @code{#t})
16810 Whether to enable syslog output.
16812 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
16813 File name of the daemon's PID file.
16815 @item @code{root-login?} (default: @code{#f})
16816 Whether to allow @code{root} logins.
16818 @item @code{allow-empty-passwords?} (default: @code{#f})
16819 Whether to allow empty passwords.
16821 @item @code{password-authentication?} (default: @code{#t})
16822 Whether to enable password-based authentication.
16827 @deffn {Scheme Variable} autossh-service-type
16828 This is the type for the @uref{https://www.harding.motd.ca/autossh,
16829 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
16830 restarting it as necessary should it die or stop passing traffic.
16831 AutoSSH can be run manually from the command-line by passing arguments
16832 to the binary @command{autossh} from the package @code{autossh}, but it
16833 can also be run as a Guix service. This latter use case is documented
16836 AutoSSH can be used to forward local traffic to a remote machine using
16837 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
16840 For example, to specify a service running autossh as the user
16841 @code{pino} and forwarding all local connections to port @code{8081} to
16842 @code{remote:8081} using an SSH tunnel, add this call to the operating
16843 system's @code{services} field:
16846 (service autossh-service-type
16847 (autossh-configuration
16849 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
16853 @deftp {Data Type} autossh-configuration
16854 This data type represents the configuration of an AutoSSH service.
16858 @item @code{user} (default @code{"autossh"})
16859 The user as which the AutoSSH service is to be run.
16860 This assumes that the specified user exists.
16862 @item @code{poll} (default @code{600})
16863 Specifies the connection poll time in seconds.
16865 @item @code{first-poll} (default @code{#f})
16866 Specifies how many seconds AutoSSH waits before the first connection
16867 test. After this first test, polling is resumed at the pace defined in
16868 @code{poll}. When set to @code{#f}, the first poll is not treated
16869 specially and will also use the connection poll specified in
16872 @item @code{gate-time} (default @code{30})
16873 Specifies how many seconds an SSH connection must be active before it is
16874 considered successful.
16876 @item @code{log-level} (default @code{1})
16877 The log level, corresponding to the levels used by syslog---so @code{0}
16878 is the most silent while @code{7} is the chattiest.
16880 @item @code{max-start} (default @code{#f})
16881 The maximum number of times SSH may be (re)started before AutoSSH exits.
16882 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
16884 @item @code{message} (default @code{""})
16885 The message to append to the echo message sent when testing connections.
16887 @item @code{port} (default @code{"0"})
16888 The ports used for monitoring the connection. When set to @code{"0"},
16889 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
16890 a positive integer, ports @var{n} and @var{n}+1 are used for
16891 monitoring the connection, such that port @var{n} is the base
16892 monitoring port and @code{n+1} is the echo port. When set to
16893 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
16894 integers, the ports @var{n} and @var{m} are used for monitoring the
16895 connection, such that port @var{n} is the base monitoring port and
16896 @var{m} is the echo port.
16898 @item @code{ssh-options} (default @code{'()})
16899 The list of command-line arguments to pass to @command{ssh} when it is
16900 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
16901 may cause undefined behaviour.
16907 @deffn {Scheme Variable} webssh-service-type
16908 This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
16909 program that runs a web SSH client. WebSSH can be run manually from the
16910 command-line by passing arguments to the binary @command{wssh} from the
16911 package @code{webssh}, but it can also be run as a Guix service. This
16912 latter use case is documented here.
16914 For example, to specify a service running WebSSH on loopback interface
16915 on port @code{8888} with reject policy with a list of allowed to
16916 connection hosts, and NGINX as a reverse-proxy to this service listening
16917 for HTTPS connection, add this call to the operating system's
16918 @code{services} field:
16921 (service webssh-service-type
16922 (webssh-configuration (address "127.0.0.1")
16925 (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
16926 "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
16928 (service nginx-service-type
16929 (nginx-configuration
16932 (nginx-server-configuration
16933 (inherit %webssh-configuration-nginx)
16934 (server-name '("webssh.example.com"))
16935 (listen '("443 ssl"))
16936 (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
16937 (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
16939 (cons (nginx-location-configuration
16940 (uri "/.well-known")
16941 (body '("root /var/www;")))
16942 (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
16946 @deftp {Data Type} webssh-configuration
16947 Data type representing the configuration for @code{webssh-service}.
16950 @item @code{package} (default: @var{webssh})
16951 @code{webssh} package to use.
16953 @item @code{user-name} (default: @var{"webssh"})
16954 User name or user ID that file transfers to and from that module should take
16957 @item @code{group-name} (default: @var{"webssh"})
16958 Group name or group ID that will be used when accessing the module.
16960 @item @code{address} (default: @var{#f})
16961 IP address on which @command{webssh} listens for incoming connections.
16963 @item @code{port} (default: @var{8888})
16964 TCP port on which @command{webssh} listens for incoming connections.
16966 @item @code{policy} (default: @var{#f})
16967 Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
16969 @item @code{known-hosts} (default: @var{'()})
16970 List of hosts which allowed for SSH connection from @command{webssh}.
16972 @item @code{log-file} (default: @file{"/var/log/webssh.log"})
16973 Name of the file where @command{webssh} writes its log file.
16975 @item @code{log-level} (default: @var{#f})
16981 @defvr {Scheme Variable} %facebook-host-aliases
16982 This variable contains a string for use in @file{/etc/hosts}
16983 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
16984 line contains a entry that maps a known server name of the Facebook
16985 on-line service---e.g., @code{www.facebook.com}---to the local
16986 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
16988 This variable is typically used in the @code{hosts-file} field of an
16989 @code{operating-system} declaration (@pxref{operating-system Reference,
16990 @file{/etc/hosts}}):
16993 (use-modules (gnu) (guix))
16996 (host-name "mymachine")
16999 ;; Create a /etc/hosts file with aliases for "localhost"
17000 ;; and "mymachine", as well as for Facebook servers.
17001 (plain-file "hosts"
17002 (string-append (local-host-aliases host-name)
17003 %facebook-host-aliases))))
17006 This mechanism can prevent programs running locally, such as Web
17007 browsers, from accessing Facebook.
17010 The @code{(gnu services avahi)} provides the following definition.
17012 @defvr {Scheme Variable} avahi-service-type
17013 This is the service that runs @command{avahi-daemon}, a system-wide
17014 mDNS/DNS-SD responder that allows for service discovery and
17015 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
17016 Its value must be an @code{avahi-configuration} record---see below.
17018 This service extends the name service cache daemon (nscd) so that it can
17019 resolve @code{.local} host names using
17020 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
17021 Service Switch}, for information on host name resolution.
17023 Additionally, add the @var{avahi} package to the system profile so that
17024 commands such as @command{avahi-browse} are directly usable.
17027 @deftp {Data Type} avahi-configuration
17028 Data type representation the configuration for Avahi.
17032 @item @code{host-name} (default: @code{#f})
17033 If different from @code{#f}, use that as the host name to
17034 publish for this machine; otherwise, use the machine's actual host name.
17036 @item @code{publish?} (default: @code{#t})
17037 When true, allow host names and services to be published (broadcast) over the
17040 @item @code{publish-workstation?} (default: @code{#t})
17041 When true, @command{avahi-daemon} publishes the machine's host name and IP
17042 address via mDNS on the local network. To view the host names published on
17043 your local network, you can run:
17046 avahi-browse _workstation._tcp
17049 @item @code{wide-area?} (default: @code{#f})
17050 When true, DNS-SD over unicast DNS is enabled.
17052 @item @code{ipv4?} (default: @code{#t})
17053 @itemx @code{ipv6?} (default: @code{#t})
17054 These fields determine whether to use IPv4/IPv6 sockets.
17056 @item @code{domains-to-browse} (default: @code{'()})
17057 This is a list of domains to browse.
17061 @deffn {Scheme Variable} openvswitch-service-type
17062 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
17063 service, whose value should be an @code{openvswitch-configuration}
17067 @deftp {Data Type} openvswitch-configuration
17068 Data type representing the configuration of Open vSwitch, a multilayer
17069 virtual switch which is designed to enable massive network automation
17070 through programmatic extension.
17073 @item @code{package} (default: @var{openvswitch})
17074 Package object of the Open vSwitch.
17079 @defvr {Scheme Variable} pagekite-service-type
17080 This is the service type for the @uref{https://pagekite.net, PageKite} service,
17081 a tunneling solution for making localhost servers publicly visible, even from
17082 behind restrictive firewalls or NAT without forwarded ports. The value for
17083 this service type is a @code{pagekite-configuration} record.
17085 Here's an example exposing the local HTTP and SSH daemons:
17088 (service pagekite-service-type
17089 (pagekite-configuration
17090 (kites '("http:@@kitename:localhost:80:@@kitesecret"
17091 "raw/22:@@kitename:localhost:22:@@kitesecret"))
17092 (extra-file "/etc/pagekite.rc")))
17096 @deftp {Data Type} pagekite-configuration
17097 Data type representing the configuration of PageKite.
17100 @item @code{package} (default: @var{pagekite})
17101 Package object of PageKite.
17103 @item @code{kitename} (default: @code{#f})
17104 PageKite name for authenticating to the frontend server.
17106 @item @code{kitesecret} (default: @code{#f})
17107 Shared secret for authenticating to the frontend server. You should probably
17108 put this inside @code{extra-file} instead.
17110 @item @code{frontend} (default: @code{#f})
17111 Connect to the named PageKite frontend server instead of the
17112 @uref{https://pagekite.net,,pagekite.net} service.
17114 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
17115 List of service kites to use. Exposes HTTP on port 80 by default. The format
17116 is @code{proto:kitename:host:port:secret}.
17118 @item @code{extra-file} (default: @code{#f})
17119 Extra configuration file to read, which you are expected to create manually.
17120 Use this to add additional options and manage shared secrets out-of-band.
17125 @defvr {Scheme Variable} yggdrasil-service-type
17126 The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
17127 Yggdrasil network}, an early-stage implementation of a fully end-to-end
17128 encrypted IPv6 network.
17131 Yggdrasil provides name-independent routing with cryptographically generated
17132 addresses. Static addressing means you can keep the same address as long as
17133 you want, even if you move to a new location, or generate a new address (by
17134 generating new keys) whenever you want.
17135 @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
17138 Pass it a value of @code{yggdrasil-configuration} to connect it to public
17139 peers and/or local peers.
17141 Here is an example using public peers and a static address. The static
17142 signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
17143 (the default value for @code{config-file}).
17146 ;; part of the operating-system declaration
17147 (service yggdrasil-service-type
17148 (yggdrasil-configuration
17149 (autoconf? #f) ;; use only the public peers
17152 ;; https://github.com/yggdrasil-network/public-peers
17153 '((peers . #("tcp://1.2.3.4:1337"))))
17154 ;; /etc/yggdrasil-private.conf is the default value for config-file
17158 # sample content for /etc/yggdrasil-private.conf
17160 # Your public encryption key. Your peers may ask you for this to put
17161 # into their AllowedEncryptionPublicKeys configuration.
17162 EncryptionPublicKey: 378dc5...
17164 # Your private encryption key. DO NOT share this with anyone!
17165 EncryptionPrivateKey: 0777...
17167 # Your public signing key. You should not ordinarily need to share
17168 # this with anyone.
17169 SigningPublicKey: e1664...
17171 # Your private signing key. DO NOT share this with anyone!
17172 SigningPrivateKey: 0589d...
17177 @deftp {Data Type} yggdrasil-configuration
17178 Data type representing the configuration of Yggdrasil.
17181 @item @code{package} (default: @code{yggdrasil})
17182 Package object of Yggdrasil.
17184 @item @code{json-config} (default: @code{'()})
17185 Contents of @file{/etc/yggdrasil.conf}. Will be merged with
17186 @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
17187 the Guix store, which is readable to all users. @strong{Do not store your
17188 private keys in it}. See the output of @code{yggdrasil -genconf} for a
17189 quick overview of valid keys and their default values.
17191 @item @code{autoconf?} (default: @code{#f})
17192 Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
17193 and peer with IPv6 neighbors.
17195 @item @code{log-level} (default: @code{'info})
17196 How much detail to include in logs. Use @code{'debug} for more detail.
17198 @item @code{log-to} (default: @code{'stdout})
17199 Where to send logs. By default, the service logs standard output to
17200 @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
17201 sends output to the running syslog service.
17203 @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
17204 What HJSON file to load sensitive data from. This is where private keys
17205 should be stored, which are necessary to specify if you don't want a
17206 randomized address after each restart. Use @code{#f} to disable. Options
17207 defined in this file take precedence over @code{json-config}. Use the output
17208 of @code{yggdrasil -genconf} as a starting point. To configure a static
17209 address, delete everything except these options:
17212 @item @code{EncryptionPublicKey}
17213 @item @code{EncryptionPrivateKey}
17214 @item @code{SigningPublicKey}
17215 @item @code{SigningPrivateKey}
17221 @deffn {Scheme Variable} keepalived-service-type
17222 This is the type for the @uref{https://www.keepalived.org/, Keepalived}
17223 routing software, @command{keepalived}. Its value must be an
17224 @code{keepalived-configuration} record as in this example for master
17228 (service keepalived-service-type
17229 (keepalived-configuration
17230 (config-file (local-file "keepalived-master.conf"))))
17233 where @file{keepalived-master.conf}:
17236 vrrp_instance my-group @{
17239 virtual_router_id 100
17241 unicast_peer @{ 10.0.0.2 @}
17242 virtual_ipaddress @{
17248 and for backup machine:
17251 (service keepalived-service-type
17252 (keepalived-configuration
17253 (config-file (local-file "keepalived-backup.conf"))))
17256 where @file{keepalived-backup.conf}:
17259 vrrp_instance my-group @{
17262 virtual_router_id 100
17264 unicast_peer @{ 10.0.0.3 @}
17265 virtual_ipaddress @{
17272 @node Unattended Upgrades
17273 @subsection Unattended Upgrades
17275 @cindex unattended upgrades
17276 @cindex upgrades, unattended
17277 Guix provides a service to perform @emph{unattended upgrades}:
17278 periodically, the system automatically reconfigures itself from the
17279 latest Guix. Guix System has several properties that make unattended
17284 upgrades are transactional (either the upgrade succeeds or it fails, but
17285 you cannot end up with an ``in-between'' system state);
17287 the upgrade log is kept---you can view it with @command{guix system
17288 list-generations}---and you can roll back to any previous generation,
17289 should the upgraded system fail to behave as intended;
17291 channel code is authenticated so you know you can only run genuine code
17292 (@pxref{Channels});
17294 @command{guix system reconfigure} prevents downgrades, which makes it
17295 immune to @dfn{downgrade attacks}.
17298 To set up unattended upgrades, add an instance of
17299 @code{unattended-upgrade-service-type} like the one below to the list of
17300 your operating system services:
17303 (service unattended-upgrade-service-type)
17306 The defaults above set up weekly upgrades: every Sunday at midnight.
17307 You do not need to provide the operating system configuration file: it
17308 uses @file{/run/current-system/configuration.scm}, which ensures it
17309 always uses your latest configuration---@pxref{provenance-service-type},
17310 for more information about this file.
17312 There are several things that can be configured, in particular the
17313 periodicity and services (daemons) to be restarted upon completion.
17314 When the upgrade is successful, the service takes care of deleting
17315 system generations older that some threshold, as per @command{guix
17316 system delete-generations}. See the reference below for details.
17318 To ensure that upgrades are actually happening, you can run
17319 @command{guix system describe}. To investigate upgrade failures, visit
17320 the unattended upgrade log file (see below).
17322 @defvr {Scheme Variable} unattended-upgrade-service-type
17323 This is the service type for unattended upgrades. It sets up an mcron
17324 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
17325 reconfigure} from the latest version of the specified channels.
17327 Its value must be a @code{unattended-upgrade-configuration} record (see
17331 @deftp {Data Type} unattended-upgrade-configuration
17332 This data type represents the configuration of the unattended upgrade
17333 service. The following fields are available:
17336 @item @code{schedule} (default: @code{"30 01 * * 0"})
17337 This is the schedule of upgrades, expressed as a gexp containing an
17338 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
17339 mcron, GNU@tie{}mcron}).
17341 @item @code{channels} (default: @code{#~%default-channels})
17342 This gexp specifies the channels to use for the upgrade
17343 (@pxref{Channels}). By default, the tip of the official @code{guix}
17346 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
17347 This field specifies the operating system configuration file to use.
17348 The default is to reuse the config file of the current configuration.
17350 There are cases, though, where referring to
17351 @file{/run/current-system/configuration.scm} is not enough, for instance
17352 because that file refers to extra files (SSH public keys, extra
17353 configuration files, etc.) @i{via} @code{local-file} and similar
17354 constructs. For those cases, we recommend something along these lines:
17357 (unattended-upgrade-configuration
17358 (operating-system-file
17359 (file-append (local-file "." "config-dir" #:recursive? #t)
17363 The effect here is to import all of the current directory into the
17364 store, and to refer to @file{config.scm} within that directory.
17365 Therefore, uses of @code{local-file} within @file{config.scm} will work
17366 as expected. @xref{G-Expressions}, for information about
17367 @code{local-file} and @code{file-append}.
17369 @item @code{services-to-restart} (default: @code{'(mcron)})
17370 This field specifies the Shepherd services to restart when the upgrade
17373 Those services are restarted right away upon completion, as with
17374 @command{herd restart}, which ensures that the latest version is
17375 running---remember that by default @command{guix system reconfigure}
17376 only restarts services that are not currently running, which is
17377 conservative: it minimizes disruption but leaves outdated services
17380 Use @command{herd status} to find out candidates for restarting.
17381 @xref{Services}, for general information about services. Common
17382 services to restart would include @code{ntpd} and @code{ssh-daemon}.
17384 By default, the @code{mcron} service is restarted. This ensures that
17385 the latest version of the unattended upgrade job will be used next time.
17387 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
17388 This is the expiration time in seconds for system generations. System
17389 generations older that this amount of time are deleted with
17390 @command{guix system delete-generations} when an upgrade completes.
17393 The unattended upgrade service does not run the garbage collector. You
17394 will probably want to set up your own mcron job to run @command{guix gc}
17398 @item @code{maximum-duration} (default: @code{3600})
17399 Maximum duration in seconds for the upgrade; past that time, the upgrade
17402 This is primarily useful to ensure the upgrade does not end up
17403 rebuilding or re-downloading ``the world''.
17405 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
17406 File where unattended upgrades are logged.
17411 @subsection X Window
17414 @cindex X Window System
17415 @cindex login manager
17416 Support for the X Window graphical display system---specifically
17417 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
17418 there is no @code{xorg-service} procedure. Instead, the X server is
17419 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
17422 @cindex GNOME, login manager
17423 GDM of course allows users to log in into window managers and desktop
17424 environments other than GNOME; for those using GNOME, GDM is required for
17425 features such as automatic screen locking.
17427 @cindex window manager
17428 To use X11, you must install at least one @dfn{window manager}---for
17429 example the @code{windowmaker} or @code{openbox} packages---preferably
17430 by adding it to the @code{packages} field of your operating system
17431 definition (@pxref{operating-system Reference, system-wide packages}).
17433 @defvr {Scheme Variable} gdm-service-type
17434 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
17435 Desktop Manager} (GDM), a program that manages graphical display servers and
17436 handles graphical user logins. Its value must be a @code{gdm-configuration}
17439 @cindex session types (X11)
17440 @cindex X11 session types
17441 GDM looks for @dfn{session types} described by the @file{.desktop} files in
17442 @file{/run/current-system/profile/share/xsessions} and allows users to choose
17443 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
17444 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
17445 set of packages automatically makes them available at the log-in screen.
17447 In addition, @file{~/.xsession} files are honored. When available,
17448 @file{~/.xsession} must be an executable that starts a window manager
17449 and/or other X clients.
17452 @deftp {Data Type} gdm-configuration
17454 @item @code{auto-login?} (default: @code{#f})
17455 @itemx @code{default-user} (default: @code{#f})
17456 When @code{auto-login?} is false, GDM presents a log-in screen.
17458 When @code{auto-login?} is true, GDM logs in directly as
17459 @code{default-user}.
17461 @item @code{debug?} (default: @code{#f})
17462 When true, GDM writes debug messages to its log.
17464 @item @code{gnome-shell-assets} (default: ...)
17465 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
17467 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
17468 Configuration of the Xorg graphical server.
17470 @item @code{xsession} (default: @code{(xinitrc)})
17471 Script to run before starting a X session.
17473 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
17474 File name of the @code{dbus-daemon} executable.
17476 @item @code{gdm} (default: @code{gdm})
17477 The GDM package to use.
17481 @defvr {Scheme Variable} slim-service-type
17482 This is the type for the SLiM graphical login manager for X11.
17484 Like GDM, SLiM looks for session types described by @file{.desktop} files and
17485 allows users to choose a session from the log-in screen using @kbd{F1}. It
17486 also honors @file{~/.xsession} files.
17488 Unlike GDM, SLiM does not spawn the user session on a different VT after
17489 logging in, which means that you can only start one graphical session. If you
17490 want to be able to run multiple graphical sessions at the same time you have
17491 to add multiple SLiM services to your system services. The following example
17492 shows how to replace the default GDM service with two SLiM services on tty7
17496 (use-modules (gnu services)
17497 (gnu services desktop)
17498 (gnu services xorg)
17499 (srfi srfi-1)) ;for 'remove'
17503 (services (cons* (service slim-service-type (slim-configuration
17506 (service slim-service-type (slim-configuration
17509 (remove (lambda (service)
17510 (eq? (service-kind service) gdm-service-type))
17511 %desktop-services))))
17516 @deftp {Data Type} slim-configuration
17517 Data type representing the configuration of @code{slim-service-type}.
17520 @item @code{allow-empty-passwords?} (default: @code{#t})
17521 Whether to allow logins with empty passwords.
17523 @item @code{auto-login?} (default: @code{#f})
17524 @itemx @code{default-user} (default: @code{""})
17525 When @code{auto-login?} is false, SLiM presents a log-in screen.
17527 When @code{auto-login?} is true, SLiM logs in directly as
17528 @code{default-user}.
17530 @item @code{theme} (default: @code{%default-slim-theme})
17531 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
17532 The graphical theme to use and its name.
17534 @item @code{auto-login-session} (default: @code{#f})
17535 If true, this must be the name of the executable to start as the default
17536 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
17538 If false, a session described by one of the available @file{.desktop}
17539 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
17543 You must install at least one window manager in the system profile or in
17544 your user profile. Failing to do that, if @code{auto-login-session} is
17545 false, you will be unable to log in.
17548 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17549 Configuration of the Xorg graphical server.
17551 @item @code{display} (default @code{":0"})
17552 The display on which to start the Xorg graphical server.
17554 @item @code{vt} (default @code{"vt7"})
17555 The VT on which to start the Xorg graphical server.
17557 @item @code{xauth} (default: @code{xauth})
17558 The XAuth package to use.
17560 @item @code{shepherd} (default: @code{shepherd})
17561 The Shepherd package used when invoking @command{halt} and
17564 @item @code{sessreg} (default: @code{sessreg})
17565 The sessreg package used in order to register the session.
17567 @item @code{slim} (default: @code{slim})
17568 The SLiM package to use.
17572 @defvr {Scheme Variable} %default-theme
17573 @defvrx {Scheme Variable} %default-theme-name
17574 The default SLiM theme and its name.
17578 @deftp {Data Type} sddm-configuration
17579 This is the data type representing the SDDM service configuration.
17582 @item @code{display-server} (default: "x11")
17583 Select display server to use for the greeter. Valid values are
17584 @samp{"x11"} or @samp{"wayland"}.
17586 @item @code{numlock} (default: "on")
17587 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
17589 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
17590 Command to run when halting.
17592 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
17593 Command to run when rebooting.
17595 @item @code{theme} (default "maldives")
17596 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
17597 @samp{"maldives"} or @samp{"maya"}.
17599 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
17600 Directory to look for themes.
17602 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
17603 Directory to look for faces.
17605 @item @code{default-path} (default "/run/current-system/profile/bin")
17606 Default PATH to use.
17608 @item @code{minimum-uid} (default: 1000)
17609 Minimum UID displayed in SDDM and allowed for log-in.
17611 @item @code{maximum-uid} (default: 2000)
17612 Maximum UID to display in SDDM.
17614 @item @code{remember-last-user?} (default #t)
17615 Remember last user.
17617 @item @code{remember-last-session?} (default #t)
17618 Remember last session.
17620 @item @code{hide-users} (default "")
17621 Usernames to hide from SDDM greeter.
17623 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
17624 Users with shells listed will be hidden from the SDDM greeter.
17626 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
17627 Script to run before starting a wayland session.
17629 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
17630 Directory to look for desktop files starting wayland sessions.
17632 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17633 Configuration of the Xorg graphical server.
17635 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
17638 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
17641 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
17642 Script to run after starting xorg-server.
17644 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
17645 Script to run before stopping xorg-server.
17647 @item @code{xsession-command} (default: @code{xinitrc})
17648 Script to run before starting a X session.
17650 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
17651 Directory to look for desktop files starting X sessions.
17653 @item @code{minimum-vt} (default: 7)
17656 @item @code{auto-login-user} (default "")
17657 User to use for auto-login.
17659 @item @code{auto-login-session} (default "")
17660 Desktop file to use for auto-login.
17662 @item @code{relogin?} (default #f)
17663 Relogin after logout.
17668 @cindex login manager
17670 @defvr {Scheme Variable} sddm-service-type
17671 This is the type of the service to run the
17672 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
17673 must be a @code{sddm-configuration} record (see below).
17675 Here's an example use:
17678 (service sddm-service-type
17679 (sddm-configuration
17680 (auto-login-user "alice")
17681 (auto-login-session "xfce.desktop")))
17685 @deftp {Data Type} sddm-configuration
17686 This data type represents the configuration of the SDDM login manager.
17687 The available fields are:
17690 @item @code{sddm} (default: @code{sddm})
17691 The SDDM package to use.
17693 @item @code{display-server} (default: @code{"x11"})
17694 This must be either @code{"x11"} or @code{"wayland"}.
17696 @c FIXME: Add more fields.
17698 @item @code{auto-login-user} (default: @code{""})
17699 If non-empty, this is the user account under which to log in
17702 @item @code{auto-login-session} (default: @code{""})
17703 If non-empty, this is the @file{.desktop} file name to use as the
17704 auto-login session.
17708 @cindex Xorg, configuration
17709 @deftp {Data Type} xorg-configuration
17710 This data type represents the configuration of the Xorg graphical display
17711 server. Note that there is no Xorg service; instead, the X server is started
17712 by a ``display manager'' such as GDM, SDDM, and SLiM. Thus, the configuration
17713 of these display managers aggregates an @code{xorg-configuration} record.
17716 @item @code{modules} (default: @code{%default-xorg-modules})
17717 This is a list of @dfn{module packages} loaded by the Xorg
17718 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
17720 @item @code{fonts} (default: @code{%default-xorg-fonts})
17721 This is a list of font directories to add to the server's @dfn{font path}.
17723 @item @code{drivers} (default: @code{'()})
17724 This must be either the empty list, in which case Xorg chooses a graphics
17725 driver automatically, or a list of driver names that will be tried in this
17726 order---e.g., @code{("modesetting" "vesa")}.
17728 @item @code{resolutions} (default: @code{'()})
17729 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
17730 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
17733 @cindex keyboard layout, for Xorg
17734 @cindex keymap, for Xorg
17735 @item @code{keyboard-layout} (default: @code{#f})
17736 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
17737 English (``qwerty'') for a 105-key PC keyboard.
17739 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
17740 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
17741 information on how to specify the keyboard layout.
17743 @item @code{extra-config} (default: @code{'()})
17744 This is a list of strings or objects appended to the configuration file. It
17745 is used to pass extra text to be added verbatim to the configuration file.
17747 @item @code{server} (default: @code{xorg-server})
17748 This is the package providing the Xorg server.
17750 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
17751 This is the list of command-line arguments to pass to the X server. The
17752 default is @code{-nolisten tcp}.
17756 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
17757 [@var{login-manager-service-type}]
17758 Tell the log-in manager (of type @var{login-manager-service-type}) to use
17759 @var{config}, an @code{<xorg-configuration>} record.
17761 Since the Xorg configuration is embedded in the log-in manager's
17762 configuration---e.g., @code{gdm-configuration}---this procedure provides a
17763 shorthand to set the Xorg configuration.
17766 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
17767 Return a @code{startx} script in which the modules, fonts, etc. specified
17768 in @var{config}, are available. The result should be used in place of
17771 Usually the X server is started by a login manager.
17775 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
17776 Add @var{package}, a package for a screen locker or screen saver whose
17777 command is @var{program}, to the set of setuid programs and add a PAM entry
17778 for it. For example:
17781 (screen-locker-service xlockmore "xlock")
17784 makes the good ol' XlockMore usable.
17788 @node Printing Services
17789 @subsection Printing Services
17791 @cindex printer support with CUPS
17792 The @code{(gnu services cups)} module provides a Guix service definition
17793 for the CUPS printing service. To add printer support to a Guix
17794 system, add a @code{cups-service} to the operating system definition:
17796 @deffn {Scheme Variable} cups-service-type
17797 The service type for the CUPS print server. Its value should be a valid
17798 CUPS configuration (see below). To use the default settings, simply
17801 (service cups-service-type)
17805 The CUPS configuration controls the basic things about your CUPS
17806 installation: what interfaces it listens on, what to do if a print job
17807 fails, how much logging to do, and so on. To actually add a printer,
17808 you have to visit the @url{http://localhost:631} URL, or use a tool such
17809 as GNOME's printer configuration services. By default, configuring a
17810 CUPS service will generate a self-signed certificate if needed, for
17811 secure connections to the print server.
17813 Suppose you want to enable the Web interface of CUPS and also add
17814 support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
17815 package and for HP printers @i{via} the @code{hplip-minimal} package.
17816 You can do that directly, like this (you need to use the
17817 @code{(gnu packages cups)} module):
17820 (service cups-service-type
17821 (cups-configuration
17822 (web-interface? #t)
17824 (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
17827 Note: If you wish to use the Qt5 based GUI which comes with the hplip
17828 package then it is suggested that you install the @code{hplip} package,
17829 either in your OS configuration file or as your user.
17831 The available configuration parameters follow. Each parameter
17832 definition is preceded by its type; for example, @samp{string-list foo}
17833 indicates that the @code{foo} parameter should be specified as a list of
17834 strings. There is also a way to specify the configuration as a string,
17835 if you have an old @code{cupsd.conf} file that you want to port over
17836 from some other system; see the end for more details.
17838 @c The following documentation was initially generated by
17839 @c (generate-documentation) in (gnu services cups). Manually maintained
17840 @c documentation is better, so we shouldn't hesitate to edit below as
17841 @c needed. However if the change you want to make to this documentation
17842 @c can be done in an automated way, it's probably easier to change
17843 @c (generate-documentation) than to make it below and have to deal with
17844 @c the churn as CUPS updates.
17847 Available @code{cups-configuration} fields are:
17849 @deftypevr {@code{cups-configuration} parameter} package cups
17853 @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list brlaser cups-filters epson-inkjet-printer-escpr foomatic-filters hplip-minimal splix)})
17854 Drivers and other extensions to the CUPS package.
17857 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
17858 Configuration of where to write logs, what directories to use for print
17859 spools, and related privileged configuration parameters.
17861 Available @code{files-configuration} fields are:
17863 @deftypevr {@code{files-configuration} parameter} log-location access-log
17864 Defines the access log filename. Specifying a blank filename disables
17865 access log generation. The value @code{stderr} causes log entries to be
17866 sent to the standard error file when the scheduler is running in the
17867 foreground, or to the system log daemon when run in the background. The
17868 value @code{syslog} causes log entries to be sent to the system log
17869 daemon. The server name may be included in filenames using the string
17870 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
17872 Defaults to @samp{"/var/log/cups/access_log"}.
17875 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
17876 Where CUPS should cache data.
17878 Defaults to @samp{"/var/cache/cups"}.
17881 @deftypevr {@code{files-configuration} parameter} string config-file-perm
17882 Specifies the permissions for all configuration files that the scheduler
17885 Note that the permissions for the printers.conf file are currently
17886 masked to only allow access from the scheduler user (typically root).
17887 This is done because printer device URIs sometimes contain sensitive
17888 authentication information that should not be generally known on the
17889 system. There is no way to disable this security feature.
17891 Defaults to @samp{"0640"}.
17894 @deftypevr {@code{files-configuration} parameter} log-location error-log
17895 Defines the error log filename. Specifying a blank filename disables
17896 error log generation. The value @code{stderr} causes log entries to be
17897 sent to the standard error file when the scheduler is running in the
17898 foreground, or to the system log daemon when run in the background. The
17899 value @code{syslog} causes log entries to be sent to the system log
17900 daemon. The server name may be included in filenames using the string
17901 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
17903 Defaults to @samp{"/var/log/cups/error_log"}.
17906 @deftypevr {@code{files-configuration} parameter} string fatal-errors
17907 Specifies which errors are fatal, causing the scheduler to exit. The
17912 No errors are fatal.
17915 All of the errors below are fatal.
17918 Browsing initialization errors are fatal, for example failed connections
17919 to the DNS-SD daemon.
17922 Configuration file syntax errors are fatal.
17925 Listen or Port errors are fatal, except for IPv6 failures on the
17926 loopback or @code{any} addresses.
17929 Log file creation or write errors are fatal.
17932 Bad startup file permissions are fatal, for example shared TLS
17933 certificate and key files with world-read permissions.
17936 Defaults to @samp{"all -browse"}.
17939 @deftypevr {@code{files-configuration} parameter} boolean file-device?
17940 Specifies whether the file pseudo-device can be used for new printer
17941 queues. The URI @uref{file:///dev/null} is always allowed.
17943 Defaults to @samp{#f}.
17946 @deftypevr {@code{files-configuration} parameter} string group
17947 Specifies the group name or ID that will be used when executing external
17950 Defaults to @samp{"lp"}.
17953 @deftypevr {@code{files-configuration} parameter} string log-file-perm
17954 Specifies the permissions for all log files that the scheduler writes.
17956 Defaults to @samp{"0644"}.
17959 @deftypevr {@code{files-configuration} parameter} log-location page-log
17960 Defines the page log filename. Specifying a blank filename disables
17961 page log generation. The value @code{stderr} causes log entries to be
17962 sent to the standard error file when the scheduler is running in the
17963 foreground, or to the system log daemon when run in the background. The
17964 value @code{syslog} causes log entries to be sent to the system log
17965 daemon. The server name may be included in filenames using the string
17966 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
17968 Defaults to @samp{"/var/log/cups/page_log"}.
17971 @deftypevr {@code{files-configuration} parameter} string remote-root
17972 Specifies the username that is associated with unauthenticated accesses
17973 by clients claiming to be the root user. The default is @code{remroot}.
17975 Defaults to @samp{"remroot"}.
17978 @deftypevr {@code{files-configuration} parameter} file-name request-root
17979 Specifies the directory that contains print jobs and other HTTP request
17982 Defaults to @samp{"/var/spool/cups"}.
17985 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
17986 Specifies the level of security sandboxing that is applied to print
17987 filters, backends, and other child processes of the scheduler; either
17988 @code{relaxed} or @code{strict}. This directive is currently only
17989 used/supported on macOS.
17991 Defaults to @samp{strict}.
17994 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
17995 Specifies the location of TLS certificates and private keys. CUPS will
17996 look for public and private keys in this directory: @file{.crt} files
17997 for PEM-encoded certificates and corresponding @file{.key} files for
17998 PEM-encoded private keys.
18000 Defaults to @samp{"/etc/cups/ssl"}.
18003 @deftypevr {@code{files-configuration} parameter} file-name server-root
18004 Specifies the directory containing the server configuration files.
18006 Defaults to @samp{"/etc/cups"}.
18009 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
18010 Specifies whether the scheduler calls fsync(2) after writing
18011 configuration or state files.
18013 Defaults to @samp{#f}.
18016 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
18017 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
18020 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
18021 Specifies the directory where temporary files are stored.
18023 Defaults to @samp{"/var/spool/cups/tmp"}.
18026 @deftypevr {@code{files-configuration} parameter} string user
18027 Specifies the user name or ID that is used when running external
18030 Defaults to @samp{"lp"}.
18033 @deftypevr {@code{files-configuration} parameter} string set-env
18034 Set the specified environment variable to be passed to child processes.
18036 Defaults to @samp{"variable value"}.
18040 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
18041 Specifies the logging level for the AccessLog file. The @code{config}
18042 level logs when printers and classes are added, deleted, or modified and
18043 when configuration files are accessed or updated. The @code{actions}
18044 level logs when print jobs are submitted, held, released, modified, or
18045 canceled, and any of the conditions for @code{config}. The @code{all}
18046 level logs all requests.
18048 Defaults to @samp{actions}.
18051 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
18052 Specifies whether to purge job history data automatically when it is no
18053 longer required for quotas.
18055 Defaults to @samp{#f}.
18058 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
18059 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
18060 For example, @samp{"_cups" "_print"} will tell network clients that both
18061 CUPS sharing and IPP Everywhere are supported.
18063 Defaults to @samp{"_cups"}.
18066 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
18067 Specifies which protocols to use for local printer sharing.
18069 Defaults to @samp{dnssd}.
18072 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
18073 Specifies whether the CUPS web interface is advertised.
18075 Defaults to @samp{#f}.
18078 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
18079 Specifies whether shared printers are advertised.
18081 Defaults to @samp{#f}.
18084 @deftypevr {@code{cups-configuration} parameter} string classification
18085 Specifies the security classification of the server. Any valid banner
18086 name can be used, including @samp{"classified"}, @samp{"confidential"},
18087 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
18088 banner can be omitted to disable secure printing functions.
18090 Defaults to @samp{""}.
18093 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
18094 Specifies whether users may override the classification (cover page) of
18095 individual print jobs using the @code{job-sheets} option.
18097 Defaults to @samp{#f}.
18100 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
18101 Specifies the default type of authentication to use.
18103 Defaults to @samp{Basic}.
18106 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
18107 Specifies whether encryption will be used for authenticated requests.
18109 Defaults to @samp{Required}.
18112 @deftypevr {@code{cups-configuration} parameter} string default-language
18113 Specifies the default language to use for text and web content.
18115 Defaults to @samp{"en"}.
18118 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
18119 Specifies the default paper size for new print queues. @samp{"Auto"}
18120 uses a locale-specific default, while @samp{"None"} specifies there is
18121 no default paper size. Specific size names are typically
18122 @samp{"Letter"} or @samp{"A4"}.
18124 Defaults to @samp{"Auto"}.
18127 @deftypevr {@code{cups-configuration} parameter} string default-policy
18128 Specifies the default access policy to use.
18130 Defaults to @samp{"default"}.
18133 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
18134 Specifies whether local printers are shared by default.
18136 Defaults to @samp{#t}.
18139 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
18140 Specifies the delay for updating of configuration and state files, in
18141 seconds. A value of 0 causes the update to happen as soon as possible,
18142 typically within a few milliseconds.
18144 Defaults to @samp{30}.
18147 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
18148 Specifies what to do when an error occurs. Possible values are
18149 @code{abort-job}, which will discard the failed print job;
18150 @code{retry-job}, which will retry the job at a later time;
18151 @code{retry-current-job}, which retries the failed job immediately; and
18152 @code{stop-printer}, which stops the printer.
18154 Defaults to @samp{stop-printer}.
18157 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
18158 Specifies the maximum cost of filters that are run concurrently, which
18159 can be used to minimize disk, memory, and CPU resource problems. A
18160 limit of 0 disables filter limiting. An average print to a
18161 non-PostScript printer needs a filter limit of about 200. A PostScript
18162 printer needs about half that (100). Setting the limit below these
18163 thresholds will effectively limit the scheduler to printing a single job
18166 Defaults to @samp{0}.
18169 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
18170 Specifies the scheduling priority of filters that are run to print a
18171 job. The nice value ranges from 0, the highest priority, to 19, the
18174 Defaults to @samp{0}.
18177 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
18178 Specifies whether to do reverse lookups on connecting clients. The
18179 @code{double} setting causes @code{cupsd} to verify that the hostname
18180 resolved from the address matches one of the addresses returned for that
18181 hostname. Double lookups also prevent clients with unregistered
18182 addresses from connecting to your server. Only set this option to
18183 @code{#t} or @code{double} if absolutely required.
18185 Defaults to @samp{#f}.
18188 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
18189 Specifies the number of seconds to wait before killing the filters and
18190 backend associated with a canceled or held job.
18192 Defaults to @samp{30}.
18195 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
18196 Specifies the interval between retries of jobs in seconds. This is
18197 typically used for fax queues but can also be used with normal print
18198 queues whose error policy is @code{retry-job} or
18199 @code{retry-current-job}.
18201 Defaults to @samp{30}.
18204 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
18205 Specifies the number of retries that are done for jobs. This is
18206 typically used for fax queues but can also be used with normal print
18207 queues whose error policy is @code{retry-job} or
18208 @code{retry-current-job}.
18210 Defaults to @samp{5}.
18213 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
18214 Specifies whether to support HTTP keep-alive connections.
18216 Defaults to @samp{#t}.
18219 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
18220 Specifies how long an idle client connection remains open, in seconds.
18222 Defaults to @samp{30}.
18225 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
18226 Specifies the maximum size of print files, IPP requests, and HTML form
18227 data. A limit of 0 disables the limit check.
18229 Defaults to @samp{0}.
18232 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
18233 Listens on the specified interfaces for connections. Valid values are
18234 of the form @var{address}:@var{port}, where @var{address} is either an
18235 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
18236 indicate all addresses. Values can also be file names of local UNIX
18237 domain sockets. The Listen directive is similar to the Port directive
18238 but allows you to restrict access to specific interfaces or networks.
18241 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
18242 Specifies the number of pending connections that will be allowed. This
18243 normally only affects very busy servers that have reached the MaxClients
18244 limit, but can also be triggered by large numbers of simultaneous
18245 connections. When the limit is reached, the operating system will
18246 refuse additional connections until the scheduler can accept the pending
18249 Defaults to @samp{128}.
18252 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
18253 Specifies a set of additional access controls.
18255 Available @code{location-access-controls} fields are:
18257 @deftypevr {@code{location-access-controls} parameter} file-name path
18258 Specifies the URI path to which the access control applies.
18261 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
18262 Access controls for all access to this path, in the same format as the
18263 @code{access-controls} of @code{operation-access-control}.
18265 Defaults to @samp{()}.
18268 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
18269 Access controls for method-specific access to this path.
18271 Defaults to @samp{()}.
18273 Available @code{method-access-controls} fields are:
18275 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
18276 If @code{#t}, apply access controls to all methods except the listed
18277 methods. Otherwise apply to only the listed methods.
18279 Defaults to @samp{#f}.
18282 @deftypevr {@code{method-access-controls} parameter} method-list methods
18283 Methods to which this access control applies.
18285 Defaults to @samp{()}.
18288 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
18289 Access control directives, as a list of strings. Each string should be
18290 one directive, such as @samp{"Order allow,deny"}.
18292 Defaults to @samp{()}.
18297 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
18298 Specifies the number of debugging messages that are retained for logging
18299 if an error occurs in a print job. Debug messages are logged regardless
18300 of the LogLevel setting.
18302 Defaults to @samp{100}.
18305 @deftypevr {@code{cups-configuration} parameter} log-level log-level
18306 Specifies the level of logging for the ErrorLog file. The value
18307 @code{none} stops all logging while @code{debug2} logs everything.
18309 Defaults to @samp{info}.
18312 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
18313 Specifies the format of the date and time in the log files. The value
18314 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
18316 Defaults to @samp{standard}.
18319 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
18320 Specifies the maximum number of simultaneous clients that are allowed by
18323 Defaults to @samp{100}.
18326 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
18327 Specifies the maximum number of simultaneous clients that are allowed
18328 from a single address.
18330 Defaults to @samp{100}.
18333 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
18334 Specifies the maximum number of copies that a user can print of each
18337 Defaults to @samp{9999}.
18340 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
18341 Specifies the maximum time a job may remain in the @code{indefinite}
18342 hold state before it is canceled. A value of 0 disables cancellation of
18345 Defaults to @samp{0}.
18348 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
18349 Specifies the maximum number of simultaneous jobs that are allowed. Set
18350 to 0 to allow an unlimited number of jobs.
18352 Defaults to @samp{500}.
18355 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
18356 Specifies the maximum number of simultaneous jobs that are allowed per
18357 printer. A value of 0 allows up to MaxJobs jobs per printer.
18359 Defaults to @samp{0}.
18362 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
18363 Specifies the maximum number of simultaneous jobs that are allowed per
18364 user. A value of 0 allows up to MaxJobs jobs per user.
18366 Defaults to @samp{0}.
18369 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
18370 Specifies the maximum time a job may take to print before it is
18371 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
18373 Defaults to @samp{10800}.
18376 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
18377 Specifies the maximum size of the log files before they are rotated, in
18378 bytes. The value 0 disables log rotation.
18380 Defaults to @samp{1048576}.
18383 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
18384 Specifies the maximum amount of time to allow between files in a
18385 multiple file print job, in seconds.
18387 Defaults to @samp{300}.
18390 @deftypevr {@code{cups-configuration} parameter} string page-log-format
18391 Specifies the format of PageLog lines. Sequences beginning with percent
18392 (@samp{%}) characters are replaced with the corresponding information,
18393 while all other characters are copied literally. The following percent
18394 sequences are recognized:
18398 insert a single percent character
18401 insert the value of the specified IPP attribute
18404 insert the number of copies for the current page
18407 insert the current page number
18410 insert the current date and time in common log format
18416 insert the printer name
18419 insert the username
18422 A value of the empty string disables page logging. The string @code{%p
18423 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
18424 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
18427 Defaults to @samp{""}.
18430 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
18431 Passes the specified environment variable(s) to child processes; a list
18434 Defaults to @samp{()}.
18437 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
18438 Specifies named access control policies.
18440 Available @code{policy-configuration} fields are:
18442 @deftypevr {@code{policy-configuration} parameter} string name
18443 Name of the policy.
18446 @deftypevr {@code{policy-configuration} parameter} string job-private-access
18447 Specifies an access list for a job's private values. @code{@@ACL} maps
18448 to the printer's requesting-user-name-allowed or
18449 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18450 owner. @code{@@SYSTEM} maps to the groups listed for the
18451 @code{system-group} field of the @code{files-config} configuration,
18452 which is reified into the @code{cups-files.conf(5)} file. Other
18453 possible elements of the access list include specific user names, and
18454 @code{@@@var{group}} to indicate members of a specific group. The
18455 access list may also be simply @code{all} or @code{default}.
18457 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18460 @deftypevr {@code{policy-configuration} parameter} string job-private-values
18461 Specifies the list of job values to make private, or @code{all},
18462 @code{default}, or @code{none}.
18464 Defaults to @samp{"job-name job-originating-host-name
18465 job-originating-user-name phone"}.
18468 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
18469 Specifies an access list for a subscription's private values.
18470 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
18471 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18472 owner. @code{@@SYSTEM} maps to the groups listed for the
18473 @code{system-group} field of the @code{files-config} configuration,
18474 which is reified into the @code{cups-files.conf(5)} file. Other
18475 possible elements of the access list include specific user names, and
18476 @code{@@@var{group}} to indicate members of a specific group. The
18477 access list may also be simply @code{all} or @code{default}.
18479 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18482 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
18483 Specifies the list of job values to make private, or @code{all},
18484 @code{default}, or @code{none}.
18486 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
18487 notify-subscriber-user-name notify-user-data"}.
18490 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
18491 Access control by IPP operation.
18493 Defaults to @samp{()}.
18497 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
18498 Specifies whether job files (documents) are preserved after a job is
18499 printed. If a numeric value is specified, job files are preserved for
18500 the indicated number of seconds after printing. Otherwise a boolean
18501 value applies indefinitely.
18503 Defaults to @samp{86400}.
18506 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
18507 Specifies whether the job history is preserved after a job is printed.
18508 If a numeric value is specified, the job history is preserved for the
18509 indicated number of seconds after printing. If @code{#t}, the job
18510 history is preserved until the MaxJobs limit is reached.
18512 Defaults to @samp{#t}.
18515 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
18516 Specifies the amount of time to wait for job completion before
18517 restarting the scheduler.
18519 Defaults to @samp{30}.
18522 @deftypevr {@code{cups-configuration} parameter} string rip-cache
18523 Specifies the maximum amount of memory to use when converting documents
18524 into bitmaps for a printer.
18526 Defaults to @samp{"128m"}.
18529 @deftypevr {@code{cups-configuration} parameter} string server-admin
18530 Specifies the email address of the server administrator.
18532 Defaults to @samp{"root@@localhost.localdomain"}.
18535 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
18536 The ServerAlias directive is used for HTTP Host header validation when
18537 clients connect to the scheduler from external interfaces. Using the
18538 special name @code{*} can expose your system to known browser-based DNS
18539 rebinding attacks, even when accessing sites through a firewall. If the
18540 auto-discovery of alternate names does not work, we recommend listing
18541 each alternate name with a ServerAlias directive instead of using
18544 Defaults to @samp{*}.
18547 @deftypevr {@code{cups-configuration} parameter} string server-name
18548 Specifies the fully-qualified host name of the server.
18550 Defaults to @samp{"localhost"}.
18553 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
18554 Specifies what information is included in the Server header of HTTP
18555 responses. @code{None} disables the Server header. @code{ProductOnly}
18556 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
18557 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
18558 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
18559 the output of the @code{uname} command. @code{Full} reports @code{CUPS
18560 2.0.0 (@var{uname}) IPP/2.0}.
18562 Defaults to @samp{Minimal}.
18565 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
18566 Listens on the specified interfaces for encrypted connections. Valid
18567 values are of the form @var{address}:@var{port}, where @var{address} is
18568 either an IPv6 address enclosed in brackets, an IPv4 address, or
18569 @code{*} to indicate all addresses.
18571 Defaults to @samp{()}.
18574 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
18575 Sets encryption options. By default, CUPS only supports encryption
18576 using TLS v1.0 or higher using known secure cipher suites. Security is
18577 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
18578 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
18579 suites, which are required for some older clients. The @code{AllowSSL3} option
18580 enables SSL v3.0, which is required for some older clients that do not support
18581 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
18582 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
18583 protocol version to TLS v1.1.
18585 Defaults to @samp{()}.
18588 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
18589 Specifies whether the scheduler requires clients to strictly adhere to
18590 the IPP specifications.
18592 Defaults to @samp{#f}.
18595 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
18596 Specifies the HTTP request timeout, in seconds.
18598 Defaults to @samp{300}.
18602 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
18603 Specifies whether the web interface is enabled.
18605 Defaults to @samp{#f}.
18608 At this point you're probably thinking ``oh dear, Guix manual, I like
18609 you but you can stop already with the configuration options''. Indeed.
18610 However, one more point: it could be that you have an existing
18611 @code{cupsd.conf} that you want to use. In that case, you can pass an
18612 @code{opaque-cups-configuration} as the configuration of a
18613 @code{cups-service-type}.
18615 Available @code{opaque-cups-configuration} fields are:
18617 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
18621 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
18622 The contents of the @code{cupsd.conf}, as a string.
18625 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
18626 The contents of the @code{cups-files.conf} file, as a string.
18629 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
18630 strings of the same name, you could instantiate a CUPS service like
18634 (service cups-service-type
18635 (opaque-cups-configuration
18636 (cupsd.conf cupsd.conf)
18637 (cups-files.conf cups-files.conf)))
18641 @node Desktop Services
18642 @subsection Desktop Services
18644 The @code{(gnu services desktop)} module provides services that are
18645 usually useful in the context of a ``desktop'' setup---that is, on a
18646 machine running a graphical display server, possibly with graphical user
18647 interfaces, etc. It also defines services that provide specific desktop
18648 environments like GNOME, Xfce or MATE.
18650 To simplify things, the module defines a variable containing the set of
18651 services that users typically expect on a machine with a graphical
18652 environment and networking:
18654 @defvr {Scheme Variable} %desktop-services
18655 This is a list of services that builds upon @code{%base-services} and
18656 adds or adjusts services for a typical ``desktop'' setup.
18658 In particular, it adds a graphical login manager (@pxref{X Window,
18659 @code{gdm-service-type}}), screen lockers, a network management tool
18660 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
18661 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
18662 energy and color management services, the @code{elogind} login and seat
18663 manager, the Polkit privilege service, the GeoClue location service, the
18664 AccountsService daemon that allows authorized users change system passwords,
18665 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
18666 name service switch service configured to be able to use @code{nss-mdns}
18667 (@pxref{Name Service Switch, mDNS}).
18670 The @code{%desktop-services} variable can be used as the @code{services}
18671 field of an @code{operating-system} declaration (@pxref{operating-system
18672 Reference, @code{services}}).
18674 Additionally, the @code{gnome-desktop-service-type},
18675 @code{xfce-desktop-service}, @code{mate-desktop-service-type},
18676 @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
18677 procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
18678 ``add GNOME'' means that system-level services like the backlight adjustment
18679 helpers and the power management utilities are added to the system, extending
18680 @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
18681 elevated privileges on a limited number of special-purpose system interfaces.
18682 Additionally, adding a service made by @code{gnome-desktop-service-type} adds
18683 the GNOME metapackage to the system profile. Likewise, adding the Xfce
18684 service not only adds the @code{xfce} metapackage to the system profile, but
18685 it also gives the Thunar file manager the ability to open a ``root-mode'' file
18686 management window, if the user authenticates using the administrator's
18687 password via the standard polkit graphical interface. To ``add MATE'' means
18688 that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
18689 to operate with elevated privileges on a limited number of special-purpose
18690 system interfaces. Additionally, adding a service of type
18691 @code{mate-desktop-service-type} adds the MATE metapackage to the system
18692 profile. ``Adding Enlightenment'' means that @code{dbus} is extended
18693 appropriately, and several of Enlightenment's binaries are set as setuid,
18694 allowing Enlightenment's screen locker and other functionality to work as
18697 The desktop environments in Guix use the Xorg display server by
18698 default. If you'd like to use the newer display server protocol
18699 called Wayland, you need to use the @code{sddm-service} instead of
18700 GDM as the graphical login manager. You should then
18701 select the ``GNOME (Wayland)'' session in SDDM. Alternatively you can
18702 also try starting GNOME on Wayland manually from a TTY with the
18703 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
18704 gnome-session``. Currently only GNOME has support for Wayland.
18706 @defvr {Scheme Variable} gnome-desktop-service-type
18707 This is the type of the service that adds the @uref{https://www.gnome.org,
18708 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
18709 object (see below).
18711 This service adds the @code{gnome} package to the system profile, and extends
18712 polkit with the actions from @code{gnome-settings-daemon}.
18715 @deftp {Data Type} gnome-desktop-configuration
18716 Configuration record for the GNOME desktop environment.
18719 @item @code{gnome} (default: @code{gnome})
18720 The GNOME package to use.
18724 @defvr {Scheme Variable} xfce-desktop-service-type
18725 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
18726 desktop environment. Its value is an @code{xfce-desktop-configuration} object
18729 This service adds the @code{xfce} package to the system profile, and
18730 extends polkit with the ability for @code{thunar} to manipulate the file
18731 system as root from within a user session, after the user has authenticated
18732 with the administrator's password.
18734 Note that @code{xfce4-panel} and its plugin packages should be installed in
18735 the same profile to ensure compatibility. When using this service, you should
18736 add extra plugins (@code{xfce4-whiskermenu-plugin},
18737 @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
18738 @code{operating-system}.
18741 @deftp {Data Type} xfce-desktop-configuration
18742 Configuration record for the Xfce desktop environment.
18745 @item @code{xfce} (default: @code{xfce})
18746 The Xfce package to use.
18750 @deffn {Scheme Variable} mate-desktop-service-type
18751 This is the type of the service that runs the @uref{https://mate-desktop.org/,
18752 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
18753 object (see below).
18755 This service adds the @code{mate} package to the system
18756 profile, and extends polkit with the actions from
18757 @code{mate-settings-daemon}.
18760 @deftp {Data Type} mate-desktop-configuration
18761 Configuration record for the MATE desktop environment.
18764 @item @code{mate} (default: @code{mate})
18765 The MATE package to use.
18769 @deffn {Scheme Variable} lxqt-desktop-service-type
18770 This is the type of the service that runs the @uref{https://lxqt.github.io,
18771 LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
18772 object (see below).
18774 This service adds the @code{lxqt} package to the system
18778 @deftp {Data Type} lxqt-desktop-configuration
18779 Configuration record for the LXQt desktop environment.
18782 @item @code{lxqt} (default: @code{lxqt})
18783 The LXQT package to use.
18787 @deffn {Scheme Variable} enlightenment-desktop-service-type
18788 Return a service that adds the @code{enlightenment} package to the system
18789 profile, and extends dbus with actions from @code{efl}.
18792 @deftp {Data Type} enlightenment-desktop-service-configuration
18794 @item @code{enlightenment} (default: @code{enlightenment})
18795 The enlightenment package to use.
18799 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
18800 the default @code{%desktop-services} variable doesn't include any of
18801 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
18802 @code{%desktop-services} in the @code{services} field of your
18803 @code{operating-system}:
18806 (use-modules (gnu))
18807 (use-service-modules desktop)
18810 ;; cons* adds items to the list given as its last argument.
18811 (services (cons* (service gnome-desktop-service-type)
18812 (service xfce-desktop-service)
18813 %desktop-services))
18817 These desktop environments will then be available as options in the
18818 graphical login window.
18820 The actual service definitions included in @code{%desktop-services} and
18821 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
18822 are described below.
18824 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
18825 Return a service that runs the ``system bus'', using @var{dbus}, with
18826 support for @var{services}.
18828 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
18829 facility. Its system bus is used to allow system services to communicate
18830 and to be notified of system-wide events.
18832 @var{services} must be a list of packages that provide an
18833 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
18834 and policy files. For example, to allow avahi-daemon to use the system bus,
18835 @var{services} must be equal to @code{(list avahi)}.
18838 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
18839 Return a service that runs the @code{elogind} login and
18840 seat management daemon. @uref{https://github.com/elogind/elogind,
18841 Elogind} exposes a D-Bus interface that can be used to know which users
18842 are logged in, know what kind of sessions they have open, suspend the
18843 system, inhibit system suspend, reboot the system, and other tasks.
18845 Elogind handles most system-level power events for a computer, for
18846 example suspending the system when a lid is closed, or shutting it down
18847 when the power button is pressed.
18849 The @var{config} keyword argument specifies the configuration for
18850 elogind, and should be the result of an @code{(elogind-configuration
18851 (@var{parameter} @var{value})...)} invocation. Available parameters and
18852 their default values are:
18855 @item kill-user-processes?
18857 @item kill-only-users
18859 @item kill-exclude-users
18861 @item inhibit-delay-max-seconds
18863 @item handle-power-key
18865 @item handle-suspend-key
18867 @item handle-hibernate-key
18869 @item handle-lid-switch
18871 @item handle-lid-switch-docked
18873 @item handle-lid-switch-external-power
18875 @item power-key-ignore-inhibited?
18877 @item suspend-key-ignore-inhibited?
18879 @item hibernate-key-ignore-inhibited?
18881 @item lid-switch-ignore-inhibited?
18883 @item holdoff-timeout-seconds
18887 @item idle-action-seconds
18889 @item runtime-directory-size-percent
18891 @item runtime-directory-size
18895 @item suspend-state
18896 @code{("mem" "standby" "freeze")}
18899 @item hibernate-state
18901 @item hibernate-mode
18902 @code{("platform" "shutdown")}
18903 @item hybrid-sleep-state
18905 @item hybrid-sleep-mode
18906 @code{("suspend" "platform" "shutdown")}
18910 @deffn {Scheme Procedure} accountsservice-service @
18911 [#:accountsservice @var{accountsservice}]
18912 Return a service that runs AccountsService, a system service that can
18913 list available accounts, change their passwords, and so on.
18914 AccountsService integrates with PolicyKit to enable unprivileged users
18915 to acquire the capability to modify their system configuration.
18916 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
18917 accountsservice web site} for more information.
18919 The @var{accountsservice} keyword argument is the @code{accountsservice}
18920 package to expose as a service.
18923 @deffn {Scheme Procedure} polkit-service @
18924 [#:polkit @var{polkit}]
18925 Return a service that runs the
18926 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
18927 management service}, which allows system administrators to grant access to
18928 privileged operations in a structured way. By querying the Polkit service, a
18929 privileged system component can know when it should grant additional
18930 capabilities to ordinary users. For example, an ordinary user can be granted
18931 the capability to suspend the system if the user is logged in locally.
18934 @defvr {Scheme Variable} polkit-wheel-service
18935 Service that adds the @code{wheel} group as admins to the Polkit
18936 service. This makes it so that users in the @code{wheel} group are queried
18937 for their own passwords when performing administrative actions instead of
18938 @code{root}'s, similar to the behaviour used by @code{sudo}.
18941 @defvr {Scheme Variable} upower-service-type
18942 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
18943 system-wide monitor for power consumption and battery levels, with the given
18944 configuration settings.
18946 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
18947 notably used by GNOME.
18950 @deftp {Data Type} upower-configuration
18951 Data type representation the configuration for UPower.
18955 @item @code{upower} (default: @var{upower})
18956 Package to use for @code{upower}.
18958 @item @code{watts-up-pro?} (default: @code{#f})
18959 Enable the Watts Up Pro device.
18961 @item @code{poll-batteries?} (default: @code{#t})
18962 Enable polling the kernel for battery level changes.
18964 @item @code{ignore-lid?} (default: @code{#f})
18965 Ignore the lid state, this can be useful if it's incorrect on a device.
18967 @item @code{use-percentage-for-policy?} (default: @code{#f})
18968 Whether battery percentage based policy should be used. The default is to use
18969 the time left, change to @code{#t} to use the percentage.
18971 @item @code{percentage-low} (default: @code{10})
18972 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18973 at which the battery is considered low.
18975 @item @code{percentage-critical} (default: @code{3})
18976 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18977 at which the battery is considered critical.
18979 @item @code{percentage-action} (default: @code{2})
18980 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
18981 at which action will be taken.
18983 @item @code{time-low} (default: @code{1200})
18984 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18985 seconds at which the battery is considered low.
18987 @item @code{time-critical} (default: @code{300})
18988 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18989 seconds at which the battery is considered critical.
18991 @item @code{time-action} (default: @code{120})
18992 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
18993 seconds at which action will be taken.
18995 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
18996 The action taken when @code{percentage-action} or @code{time-action} is
18997 reached (depending on the configuration of @code{use-percentage-for-policy?}).
18999 Possible values are:
19009 @code{'hybrid-sleep}.
19015 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
19016 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
19017 UDisks}, a @dfn{disk management} daemon that provides user interfaces
19018 with notifications and ways to mount/unmount disks. Programs that talk
19019 to UDisks include the @command{udisksctl} command, part of UDisks, and
19020 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
19021 it will only be able to use the file-system utilities installed in the
19022 system profile. For example if you want to be able to mount NTFS
19023 file-systems in read and write fashion, you'll need to have
19024 @code{ntfs-3g} installed system-wide.
19027 @deffn {Scheme Variable} colord-service-type
19028 This is the type of the service that runs @command{colord}, a system
19029 service with a D-Bus
19030 interface to manage the color profiles of input and output devices such as
19031 screens and scanners. It is notably used by the GNOME Color Manager graphical
19032 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
19033 site} for more information.
19036 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
19037 Return a configuration allowing an application to access GeoClue
19038 location data. @var{name} is the Desktop ID of the application, without
19039 the @code{.desktop} part. If @var{allowed?} is true, the application
19040 will have access to location information by default. The boolean
19041 @var{system?} value indicates whether an application is a system component
19042 or not. Finally @var{users} is a list of UIDs of all users for which
19043 this application is allowed location info access. An empty users list
19044 means that all users are allowed.
19047 @cindex scanner access
19048 @deffn {Scheme Procedure} sane-service-type
19049 This service provides access to scanners @i{via}
19050 @uref{http://www.sane-project.org, SANE} by installing the necessary udev
19054 @defvr {Scheme Variable} %standard-geoclue-applications
19055 The standard list of well-known GeoClue application configurations,
19056 granting authority to the GNOME date-and-time utility to ask for the
19057 current location in order to set the time zone, and allowing the
19058 IceCat and Epiphany web browsers to request location information.
19059 IceCat and Epiphany both query the user before allowing a web page to
19060 know the user's location.
19063 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
19064 [#:whitelist '()] @
19065 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
19066 [#:submit-data? #f]
19067 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
19068 [#:submission-nick "geoclue"] @
19069 [#:applications %standard-geoclue-applications]
19070 Return a service that runs the GeoClue location service. This service
19071 provides a D-Bus interface to allow applications to request access to a
19072 user's physical location, and optionally to add information to online
19073 location databases. See
19074 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
19075 web site} for more information.
19078 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
19079 [@w{#:auto-enable? #f}]
19080 Return a service that runs the @command{bluetoothd} daemon, which
19081 manages all the Bluetooth devices and provides a number of D-Bus
19082 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
19083 powered automatically at boot, which can be useful when using a
19084 bluetooth keyboard or mouse.
19086 Users need to be in the @code{lp} group to access the D-Bus service.
19089 @defvr {Scheme Variable} gnome-keyring-service-type
19090 This is the type of the service that adds the
19091 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
19092 value is a @code{gnome-keyring-configuration} object (see below).
19094 This service adds the @code{gnome-keyring} package to the system profile
19095 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
19096 a user's login keyring when they log in or setting its password with passwd.
19099 @deftp {Data Type} gnome-keyring-configuration
19100 Configuration record for the GNOME Keyring service.
19103 @item @code{keyring} (default: @code{gnome-keyring})
19104 The GNOME keyring package to use.
19106 @item @code{pam-services}
19107 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
19108 services to extend, where @var{service} is the name of an existing
19109 service to extend and @var{kind} is one of @code{login} or
19112 If @code{login} is given, it adds an optional
19113 @code{pam_gnome_keyring.so} to the auth block without arguments and to
19114 the session block with @code{auto_start}. If @code{passwd} is given, it
19115 adds an optional @code{pam_gnome_keyring.so} to the password block
19118 By default, this field contains ``gdm-password'' with the value @code{login}
19119 and ``passwd'' is with the value @code{passwd}.
19124 @node Sound Services
19125 @subsection Sound Services
19127 @cindex sound support
19129 @cindex PulseAudio, sound support
19131 The @code{(gnu services sound)} module provides a service to configure the
19132 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
19133 preferred ALSA output driver.
19135 @deffn {Scheme Variable} alsa-service-type
19136 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
19137 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
19138 configuration file. The value for this type is a @command{alsa-configuration}
19139 record as in this example:
19142 (service alsa-service-type)
19145 See below for details about @code{alsa-configuration}.
19148 @deftp {Data Type} alsa-configuration
19149 Data type representing the configuration for @code{alsa-service}.
19152 @item @code{alsa-plugins} (default: @var{alsa-plugins})
19153 @code{alsa-plugins} package to use.
19155 @item @code{pulseaudio?} (default: @var{#t})
19156 Whether ALSA applications should transparently be made to use the
19157 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
19159 Using PulseAudio allows you to run several sound-producing applications
19160 at the same time and to individual control them @i{via}
19161 @command{pavucontrol}, among other things.
19163 @item @code{extra-options} (default: @var{""})
19164 String to append to the @file{/etc/asound.conf} file.
19169 Individual users who want to override the system configuration of ALSA can do
19170 it with the @file{~/.asoundrc} file:
19173 # In guix, we have to specify the absolute path for plugins.
19175 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
19178 # Routing ALSA to jack:
19179 # <http://jackaudio.org/faq/routing_alsa.html>.
19183 0 system:playback_1
19184 1 system:playback_2
19201 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
19204 @deffn {Scheme Variable} pulseaudio-service-type
19205 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
19206 sound server. It exists to allow system overrides of the default settings
19207 via @code{pulseaudio-configuration}, see below.
19210 This service overrides per-user configuration files. If you want
19211 PulseAudio to honor configuration files in @file{~/.config/pulse} you
19212 have to unset the environment variables @env{PULSE_CONFIG} and
19213 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
19217 This service on its own does not ensure, that the @code{pulseaudio} package
19218 exists on your machine. It merely adds configuration files for it, as
19219 detailed below. In the (admittedly unlikely) case, that you find yourself
19220 without a @code{pulseaudio} package, consider enabling it through the
19221 @code{alsa-service-type} above.
19225 @deftp {Data Type} pulseaudio-configuration
19226 Data type representing the configuration for @code{pulseaudio-service}.
19229 @item @code{client-conf} (default: @code{'()})
19230 List of settings to set in @file{client.conf}.
19231 Accepts a list of strings or a symbol-value pairs. A string will be
19232 inserted as-is with a newline added. A pair will be formatted as
19233 ``key = value'', again with a newline added.
19235 @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
19236 List of settings to set in @file{daemon.conf}, formatted just like
19239 @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
19240 Script file to use as @file{default.pa}.
19242 @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
19243 Script file to use as @file{system.pa}.
19247 @deffn {Scheme Variable} ladspa-service-type
19248 This service sets the @var{LADSPA_PATH} variable, so that programs, which
19249 respect it, e.g. PulseAudio, can load LADSPA plugins.
19251 The following example will setup the service to enable modules from the
19252 @code{swh-plugins} package:
19255 (service ladspa-service-type
19256 (ladspa-configuration (plugins (list swh-plugins))))
19259 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
19264 @node Database Services
19265 @subsection Database Services
19269 The @code{(gnu services databases)} module provides the following services.
19271 @subsubheading PostgreSQL
19273 The following example describes a PostgreSQL service with the default
19277 (service postgresql-service-type
19278 (postgresql-configuration
19279 (postgresql postgresql-10)))
19282 If the services fails to start, it may be due to an incompatible
19283 cluster already present in @var{data-directory}. Adjust it (or, if you
19284 don't need the cluster anymore, delete @var{data-directory}), then
19285 restart the service.
19287 Peer authentication is used by default and the @code{postgres} user
19288 account has no shell, which prevents the direct execution of @code{psql}
19289 commands as this user. To use @code{psql}, you can temporarily log in
19290 as @code{postgres} using a shell, create a PostgreSQL superuser with the
19291 same name as one of the system users and then create the associated
19295 sudo -u postgres -s /bin/sh
19296 createuser --interactive
19297 createdb $MY_USER_LOGIN # Replace appropriately.
19300 @deftp {Data Type} postgresql-configuration
19301 Data type representing the configuration for the
19302 @code{postgresql-service-type}.
19305 @item @code{postgresql}
19306 PostgreSQL package to use for the service.
19308 @item @code{port} (default: @code{5432})
19309 Port on which PostgreSQL should listen.
19311 @item @code{locale} (default: @code{"en_US.utf8"})
19312 Locale to use as the default when creating the database cluster.
19314 @item @code{config-file} (default: @code{(postgresql-config-file)})
19315 The configuration file to use when running PostgreSQL. The default
19316 behaviour uses the postgresql-config-file record with the default values
19319 @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
19320 Directory in which to store the data.
19322 @item @code{extension-packages} (default: @code{'()})
19323 @cindex postgresql extension-packages
19324 Additional extensions are loaded from packages listed in
19325 @var{extension-packages}. Extensions are available at runtime. For instance,
19326 to create a geographic database using the @code{postgis} extension, a user can
19327 configure the postgresql-service as in this example:
19331 (use-package-modules databases geo)
19335 ;; postgresql is required to run `psql' but postgis is not required for
19336 ;; proper operation.
19337 (packages (cons* postgresql %base-packages))
19340 (service postgresql-service-type
19341 (postgresql-configuration
19342 (postgresql postgresql-10)
19343 (extension-packages (list postgis))))
19347 Then the extension becomes visible and you can initialise an empty geographic
19348 database in this way:
19352 > create database postgistest;
19353 > \connect postgistest;
19354 > create extension postgis;
19355 > create extension postgis_topology;
19358 There is no need to add this field for contrib extensions such as hstore or
19359 dblink as they are already loadable by postgresql. This field is only
19360 required to add extensions provided by other packages.
19365 @deftp {Data Type} postgresql-config-file
19366 Data type representing the PostgreSQL configuration file. As shown in
19367 the following example, this can be used to customize the configuration
19368 of PostgreSQL. Note that you can use any G-expression or filename in
19369 place of this record, if you already have a configuration file you'd
19370 like to use for example.
19373 (service postgresql-service-type
19374 (postgresql-configuration
19376 (postgresql-config-file
19377 (log-destination "stderr")
19379 (plain-file "pg_hba.conf"
19381 local all all trust
19382 host all all 127.0.0.1/32 md5
19383 host all all ::1/128 md5"))
19385 '(("session_preload_libraries" "'auto_explain'")
19386 ("random_page_cost" "2")
19387 ("auto_explain.log_min_duration" "'100ms'")
19388 ("work_mem" "'500MB'")
19389 ("logging_collector" "on")
19390 ("log_directory" "'/var/log/postgresql'")))))))
19394 @item @code{log-destination} (default: @code{"syslog"})
19395 The logging method to use for PostgreSQL. Multiple values are accepted,
19396 separated by commas.
19398 @item @code{hba-file} (default: @code{%default-postgres-hba})
19399 Filename or G-expression for the host-based authentication
19402 @item @code{ident-file} (default: @code{%default-postgres-ident})
19403 Filename or G-expression for the user name mapping configuration.
19405 @item @code{extra-config} (default: @code{'()})
19406 List of additional keys and values to include in the PostgreSQL config
19407 file. Each entry in the list should be a list where the first element
19408 is the key, and the remaining elements are the values.
19413 @subsubheading MariaDB/MySQL
19415 @defvr {Scheme Variable} mysql-service-type
19416 This is the service type for a MySQL or MariaDB database server. Its value
19417 is a @code{mysql-configuration} object that specifies which package to use,
19418 as well as various settings for the @command{mysqld} daemon.
19421 @deftp {Data Type} mysql-configuration
19422 Data type representing the configuration of @var{mysql-service-type}.
19425 @item @code{mysql} (default: @var{mariadb})
19426 Package object of the MySQL database server, can be either @var{mariadb}
19429 For MySQL, a temporary root password will be displayed at activation time.
19430 For MariaDB, the root password is empty.
19432 @item @code{bind-address} (default: @code{"127.0.0.1"})
19433 The IP on which to listen for network connections. Use @code{"0.0.0.0"}
19434 to bind to all available network interfaces.
19436 @item @code{port} (default: @code{3306})
19437 TCP port on which the database server listens for incoming connections.
19439 @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
19440 Socket file to use for local (non-network) connections.
19442 @item @code{extra-content} (default: @code{""})
19443 Additional settings for the @file{my.cnf} configuration file.
19445 @item @code{auto-upgrade?} (default: @code{#t})
19446 Whether to automatically run @command{mysql_upgrade} after starting the
19447 service. This is necessary to upgrade the @dfn{system schema} after
19448 ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
19449 be disabled if you would rather do that manually.
19454 @subsubheading Memcached
19456 @defvr {Scheme Variable} memcached-service-type
19457 This is the service type for the @uref{https://memcached.org/,
19458 Memcached} service, which provides a distributed in memory cache. The
19459 value for the service type is a @code{memcached-configuration} object.
19463 (service memcached-service-type)
19466 @deftp {Data Type} memcached-configuration
19467 Data type representing the configuration of memcached.
19470 @item @code{memcached} (default: @code{memcached})
19471 The Memcached package to use.
19473 @item @code{interfaces} (default: @code{'("0.0.0.0")})
19474 Network interfaces on which to listen.
19476 @item @code{tcp-port} (default: @code{11211})
19477 Port on which to accept connections.
19479 @item @code{udp-port} (default: @code{11211})
19480 Port on which to accept UDP connections on, a value of 0 will disable
19481 listening on a UDP socket.
19483 @item @code{additional-options} (default: @code{'()})
19484 Additional command line options to pass to @code{memcached}.
19488 @subsubheading MongoDB
19490 @defvr {Scheme Variable} mongodb-service-type
19491 This is the service type for @uref{https://www.mongodb.com/, MongoDB}.
19492 The value for the service type is a @code{mongodb-configuration} object.
19496 (service mongodb-service-type)
19499 @deftp {Data Type} mongodb-configuration
19500 Data type representing the configuration of mongodb.
19503 @item @code{mongodb} (default: @code{mongodb})
19504 The MongoDB package to use.
19506 @item @code{config-file} (default: @code{%default-mongodb-configuration-file})
19507 The configuration file for MongoDB.
19509 @item @code{data-directory} (default: @code{"/var/lib/mongodb"})
19510 This value is used to create the directory, so that it exists and is
19511 owned by the mongodb user. It should match the data-directory which
19512 MongoDB is configured to use through the configuration file.
19516 @subsubheading Redis
19518 @defvr {Scheme Variable} redis-service-type
19519 This is the service type for the @uref{https://redis.io/, Redis}
19520 key/value store, whose value is a @code{redis-configuration} object.
19523 @deftp {Data Type} redis-configuration
19524 Data type representing the configuration of redis.
19527 @item @code{redis} (default: @code{redis})
19528 The Redis package to use.
19530 @item @code{bind} (default: @code{"127.0.0.1"})
19531 Network interface on which to listen.
19533 @item @code{port} (default: @code{6379})
19534 Port on which to accept connections on, a value of 0 will disable
19535 listening on a TCP socket.
19537 @item @code{working-directory} (default: @code{"/var/lib/redis"})
19538 Directory in which to store the database and related files.
19542 @node Mail Services
19543 @subsection Mail Services
19547 The @code{(gnu services mail)} module provides Guix service definitions
19548 for email services: IMAP, POP3, and LMTP servers, as well as mail
19549 transport agents (MTAs). Lots of acronyms! These services are detailed
19550 in the subsections below.
19552 @subsubheading Dovecot Service
19554 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
19555 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
19558 By default, Dovecot does not need much configuration; the default
19559 configuration object created by @code{(dovecot-configuration)} will
19560 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
19561 certificate will be generated for TLS-protected connections, though
19562 Dovecot will also listen on cleartext ports by default. There are a
19563 number of options, though, which mail administrators might need to change,
19564 and as is the case with other services, Guix allows the system
19565 administrator to specify these parameters via a uniform Scheme interface.
19567 For example, to specify that mail is located at @code{maildir~/.mail},
19568 one would instantiate the Dovecot service like this:
19571 (dovecot-service #:config
19572 (dovecot-configuration
19573 (mail-location "maildir:~/.mail")))
19576 The available configuration parameters follow. Each parameter
19577 definition is preceded by its type; for example, @samp{string-list foo}
19578 indicates that the @code{foo} parameter should be specified as a list of
19579 strings. There is also a way to specify the configuration as a string,
19580 if you have an old @code{dovecot.conf} file that you want to port over
19581 from some other system; see the end for more details.
19583 @c The following documentation was initially generated by
19584 @c (generate-documentation) in (gnu services mail). Manually maintained
19585 @c documentation is better, so we shouldn't hesitate to edit below as
19586 @c needed. However if the change you want to make to this documentation
19587 @c can be done in an automated way, it's probably easier to change
19588 @c (generate-documentation) than to make it below and have to deal with
19589 @c the churn as dovecot updates.
19591 Available @code{dovecot-configuration} fields are:
19593 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
19594 The dovecot package.
19597 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
19598 A list of IPs or hosts where to listen for connections. @samp{*}
19599 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
19600 interfaces. If you want to specify non-default ports or anything more
19601 complex, customize the address and port fields of the
19602 @samp{inet-listener} of the specific services you are interested in.
19605 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
19606 List of protocols we want to serve. Available protocols include
19607 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
19609 Available @code{protocol-configuration} fields are:
19611 @deftypevr {@code{protocol-configuration} parameter} string name
19612 The name of the protocol.
19615 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
19616 UNIX socket path to the master authentication server to find users.
19617 This is used by imap (for shared users) and lda.
19618 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
19621 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
19622 Space separated list of plugins to load.
19625 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
19626 Maximum number of IMAP connections allowed for a user from each IP
19627 address. NOTE: The username is compared case-sensitively.
19628 Defaults to @samp{10}.
19633 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
19634 List of services to enable. Available services include @samp{imap},
19635 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
19638 Available @code{service-configuration} fields are:
19640 @deftypevr {@code{service-configuration} parameter} string kind
19641 The service kind. Valid values include @code{director},
19642 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
19643 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
19644 @code{tcpwrap}, @code{quota-warning}, or anything else.
19647 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
19648 Listeners for the service. A listener is either a
19649 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
19650 an @code{inet-listener-configuration}.
19651 Defaults to @samp{()}.
19653 Available @code{unix-listener-configuration} fields are:
19655 @deftypevr {@code{unix-listener-configuration} parameter} string path
19656 Path to the file, relative to @code{base-dir} field. This is also used as
19660 @deftypevr {@code{unix-listener-configuration} parameter} string mode
19661 The access mode for the socket.
19662 Defaults to @samp{"0600"}.
19665 @deftypevr {@code{unix-listener-configuration} parameter} string user
19666 The user to own the socket.
19667 Defaults to @samp{""}.
19670 @deftypevr {@code{unix-listener-configuration} parameter} string group
19671 The group to own the socket.
19672 Defaults to @samp{""}.
19676 Available @code{fifo-listener-configuration} fields are:
19678 @deftypevr {@code{fifo-listener-configuration} parameter} string path
19679 Path to the file, relative to @code{base-dir} field. This is also used as
19683 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
19684 The access mode for the socket.
19685 Defaults to @samp{"0600"}.
19688 @deftypevr {@code{fifo-listener-configuration} parameter} string user
19689 The user to own the socket.
19690 Defaults to @samp{""}.
19693 @deftypevr {@code{fifo-listener-configuration} parameter} string group
19694 The group to own the socket.
19695 Defaults to @samp{""}.
19699 Available @code{inet-listener-configuration} fields are:
19701 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
19702 The protocol to listen for.
19705 @deftypevr {@code{inet-listener-configuration} parameter} string address
19706 The address on which to listen, or empty for all addresses.
19707 Defaults to @samp{""}.
19710 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
19711 The port on which to listen.
19714 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
19715 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
19717 Defaults to @samp{#t}.
19722 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
19723 Maximum number of simultaneous client connections per process. Once
19724 this number of connections is received, the next incoming connection
19725 will prompt Dovecot to spawn another process. If set to 0,
19726 @code{default-client-limit} is used instead.
19728 Defaults to @samp{0}.
19732 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
19733 Number of connections to handle before starting a new process.
19734 Typically the only useful values are 0 (unlimited) or 1. 1 is more
19735 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
19736 Defaults to @samp{1}.
19740 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
19741 Maximum number of processes that can exist for this service. If set to
19742 0, @code{default-process-limit} is used instead.
19744 Defaults to @samp{0}.
19748 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
19749 Number of processes to always keep waiting for more connections.
19750 Defaults to @samp{0}.
19753 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
19754 If you set @samp{service-count 0}, you probably need to grow
19756 Defaults to @samp{256000000}.
19761 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
19762 Dict configuration, as created by the @code{dict-configuration}
19765 Available @code{dict-configuration} fields are:
19767 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
19768 A list of key-value pairs that this dict should hold.
19769 Defaults to @samp{()}.
19774 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
19775 A list of passdb configurations, each one created by the
19776 @code{passdb-configuration} constructor.
19778 Available @code{passdb-configuration} fields are:
19780 @deftypevr {@code{passdb-configuration} parameter} string driver
19781 The driver that the passdb should use. Valid values include
19782 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
19784 Defaults to @samp{"pam"}.
19787 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
19788 Space separated list of arguments to the passdb driver.
19789 Defaults to @samp{""}.
19794 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
19795 List of userdb configurations, each one created by the
19796 @code{userdb-configuration} constructor.
19798 Available @code{userdb-configuration} fields are:
19800 @deftypevr {@code{userdb-configuration} parameter} string driver
19801 The driver that the userdb should use. Valid values include
19802 @samp{passwd} and @samp{static}.
19803 Defaults to @samp{"passwd"}.
19806 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
19807 Space separated list of arguments to the userdb driver.
19808 Defaults to @samp{""}.
19811 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
19812 Override fields from passwd.
19813 Defaults to @samp{()}.
19818 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
19819 Plug-in configuration, created by the @code{plugin-configuration}
19823 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
19824 List of namespaces. Each item in the list is created by the
19825 @code{namespace-configuration} constructor.
19827 Available @code{namespace-configuration} fields are:
19829 @deftypevr {@code{namespace-configuration} parameter} string name
19830 Name for this namespace.
19833 @deftypevr {@code{namespace-configuration} parameter} string type
19834 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
19835 Defaults to @samp{"private"}.
19838 @deftypevr {@code{namespace-configuration} parameter} string separator
19839 Hierarchy separator to use. You should use the same separator for
19840 all namespaces or some clients get confused. @samp{/} is usually a good
19841 one. The default however depends on the underlying mail storage
19843 Defaults to @samp{""}.
19846 @deftypevr {@code{namespace-configuration} parameter} string prefix
19847 Prefix required to access this namespace. This needs to be
19848 different for all namespaces. For example @samp{Public/}.
19849 Defaults to @samp{""}.
19852 @deftypevr {@code{namespace-configuration} parameter} string location
19853 Physical location of the mailbox. This is in the same format as
19854 mail_location, which is also the default for it.
19855 Defaults to @samp{""}.
19858 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
19859 There can be only one INBOX, and this setting defines which
19861 Defaults to @samp{#f}.
19864 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
19865 If namespace is hidden, it's not advertised to clients via NAMESPACE
19866 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
19867 useful when converting from another server with different namespaces
19868 which you want to deprecate but still keep working. For example you can
19869 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
19871 Defaults to @samp{#f}.
19874 @deftypevr {@code{namespace-configuration} parameter} boolean list?
19875 Show the mailboxes under this namespace with the LIST command. This
19876 makes the namespace visible for clients that do not support the NAMESPACE
19877 extension. The special @code{children} value lists child mailboxes, but
19878 hides the namespace prefix.
19879 Defaults to @samp{#t}.
19882 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
19883 Namespace handles its own subscriptions. If set to @code{#f}, the
19884 parent namespace handles them. The empty prefix should always have this
19886 Defaults to @samp{#t}.
19889 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
19890 List of predefined mailboxes in this namespace.
19891 Defaults to @samp{()}.
19893 Available @code{mailbox-configuration} fields are:
19895 @deftypevr {@code{mailbox-configuration} parameter} string name
19896 Name for this mailbox.
19899 @deftypevr {@code{mailbox-configuration} parameter} string auto
19900 @samp{create} will automatically create this mailbox.
19901 @samp{subscribe} will both create and subscribe to the mailbox.
19902 Defaults to @samp{"no"}.
19905 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
19906 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
19907 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
19908 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
19909 Defaults to @samp{()}.
19916 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
19917 Base directory where to store runtime data.
19918 Defaults to @samp{"/var/run/dovecot/"}.
19921 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
19922 Greeting message for clients.
19923 Defaults to @samp{"Dovecot ready."}.
19926 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
19927 List of trusted network ranges. Connections from these IPs are
19928 allowed to override their IP addresses and ports (for logging and for
19929 authentication checks). @samp{disable-plaintext-auth} is also ignored
19930 for these networks. Typically you would specify your IMAP proxy servers
19932 Defaults to @samp{()}.
19935 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
19936 List of login access check sockets (e.g.@: tcpwrap).
19937 Defaults to @samp{()}.
19940 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
19941 Show more verbose process titles (in ps). Currently shows user name
19942 and IP address. Useful for seeing who is actually using the IMAP
19943 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
19945 Defaults to @samp{#f}.
19948 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
19949 Should all processes be killed when Dovecot master process shuts down.
19950 Setting this to @code{#f} means that Dovecot can be upgraded without
19951 forcing existing client connections to close (although that could also
19952 be a problem if the upgrade is e.g.@: due to a security fix).
19953 Defaults to @samp{#t}.
19956 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
19957 If non-zero, run mail commands via this many connections to doveadm
19958 server, instead of running them directly in the same process.
19959 Defaults to @samp{0}.
19962 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
19963 UNIX socket or host:port used for connecting to doveadm server.
19964 Defaults to @samp{"doveadm-server"}.
19967 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
19968 List of environment variables that are preserved on Dovecot startup
19969 and passed down to all of its child processes. You can also give
19970 key=value pairs to always set specific settings.
19973 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
19974 Disable LOGIN command and all other plaintext authentications unless
19975 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
19976 matches the local IP (i.e.@: you're connecting from the same computer),
19977 the connection is considered secure and plaintext authentication is
19978 allowed. See also ssl=required setting.
19979 Defaults to @samp{#t}.
19982 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
19983 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
19984 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
19985 for caching to be used.
19986 Defaults to @samp{0}.
19989 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
19990 Time to live for cached data. After TTL expires the cached record
19991 is no longer used, *except* if the main database lookup returns internal
19992 failure. We also try to handle password changes automatically: If
19993 user's previous authentication was successful, but this one wasn't, the
19994 cache isn't used. For now this works only with plaintext
19996 Defaults to @samp{"1 hour"}.
19999 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
20000 TTL for negative hits (user not found, password mismatch).
20001 0 disables caching them completely.
20002 Defaults to @samp{"1 hour"}.
20005 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
20006 List of realms for SASL authentication mechanisms that need them.
20007 You can leave it empty if you don't want to support multiple realms.
20008 Many clients simply use the first one listed here, so keep the default
20010 Defaults to @samp{()}.
20013 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
20014 Default realm/domain to use if none was specified. This is used for
20015 both SASL realms and appending @@domain to username in plaintext
20017 Defaults to @samp{""}.
20020 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
20021 List of allowed characters in username. If the user-given username
20022 contains a character not listed in here, the login automatically fails.
20023 This is just an extra check to make sure user can't exploit any
20024 potential quote escaping vulnerabilities with SQL/LDAP databases. If
20025 you want to allow all characters, set this value to empty.
20026 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
20029 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
20030 Username character translations before it's looked up from
20031 databases. The value contains series of from -> to characters. For
20032 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
20033 translated to @samp{@@}.
20034 Defaults to @samp{""}.
20037 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
20038 Username formatting before it's looked up from databases. You can
20039 use the standard variables here, e.g.@: %Lu would lowercase the username,
20040 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
20041 change the @samp{@@} into @samp{-AT-}. This translation is done after
20042 @samp{auth-username-translation} changes.
20043 Defaults to @samp{"%Lu"}.
20046 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
20047 If you want to allow master users to log in by specifying the master
20048 username within the normal username string (i.e.@: not using SASL
20049 mechanism's support for it), you can specify the separator character
20050 here. The format is then <username><separator><master username>.
20051 UW-IMAP uses @samp{*} as the separator, so that could be a good
20053 Defaults to @samp{""}.
20056 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
20057 Username to use for users logging in with ANONYMOUS SASL
20059 Defaults to @samp{"anonymous"}.
20062 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
20063 Maximum number of dovecot-auth worker processes. They're used to
20064 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
20065 They're automatically created and destroyed as needed.
20066 Defaults to @samp{30}.
20069 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
20070 Host name to use in GSSAPI principal names. The default is to use
20071 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
20072 allow all keytab entries.
20073 Defaults to @samp{""}.
20076 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
20077 Kerberos keytab to use for the GSSAPI mechanism. Will use the
20078 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
20079 need to change the auth service to run as root to be able to read this
20081 Defaults to @samp{""}.
20084 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
20085 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
20086 and @samp{ntlm-auth} helper.
20087 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
20088 Defaults to @samp{#f}.
20091 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
20092 Path for Samba's @samp{ntlm-auth} helper binary.
20093 Defaults to @samp{"/usr/bin/ntlm_auth"}.
20096 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
20097 Time to delay before replying to failed authentications.
20098 Defaults to @samp{"2 secs"}.
20101 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
20102 Require a valid SSL client certificate or the authentication
20104 Defaults to @samp{#f}.
20107 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
20108 Take the username from client's SSL certificate, using
20109 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
20111 Defaults to @samp{#f}.
20114 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
20115 List of wanted authentication mechanisms. Supported mechanisms are:
20116 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
20117 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
20118 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
20119 @samp{disable-plaintext-auth} setting.
20122 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
20123 List of IPs or hostnames to all director servers, including ourself.
20124 Ports can be specified as ip:port. The default port is the same as what
20125 director service's @samp{inet-listener} is using.
20126 Defaults to @samp{()}.
20129 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
20130 List of IPs or hostnames to all backend mail servers. Ranges are
20131 allowed too, like 10.0.0.10-10.0.0.30.
20132 Defaults to @samp{()}.
20135 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
20136 How long to redirect users to a specific server after it no longer
20137 has any connections.
20138 Defaults to @samp{"15 min"}.
20141 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
20142 How the username is translated before being hashed. Useful values
20143 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
20144 are shared within domain.
20145 Defaults to @samp{"%Lu"}.
20148 @deftypevr {@code{dovecot-configuration} parameter} string log-path
20149 Log file to use for error messages. @samp{syslog} logs to syslog,
20150 @samp{/dev/stderr} logs to stderr.
20151 Defaults to @samp{"syslog"}.
20154 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
20155 Log file to use for informational messages. Defaults to
20157 Defaults to @samp{""}.
20160 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
20161 Log file to use for debug messages. Defaults to
20162 @samp{info-log-path}.
20163 Defaults to @samp{""}.
20166 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
20167 Syslog facility to use if you're logging to syslog. Usually if you
20168 don't want to use @samp{mail}, you'll use local0..local7. Also other
20169 standard facilities are supported.
20170 Defaults to @samp{"mail"}.
20173 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
20174 Log unsuccessful authentication attempts and the reasons why they
20176 Defaults to @samp{#f}.
20179 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
20180 In case of password mismatches, log the attempted password. Valid
20181 values are no, plain and sha1. sha1 can be useful for detecting brute
20182 force password attempts vs. user simply trying the same password over
20183 and over again. You can also truncate the value to n chars by appending
20184 ":n" (e.g.@: sha1:6).
20185 Defaults to @samp{"no"}.
20188 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
20189 Even more verbose logging for debugging purposes. Shows for example
20191 Defaults to @samp{#f}.
20194 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
20195 In case of password mismatches, log the passwords and used scheme so
20196 the problem can be debugged. Enabling this also enables
20198 Defaults to @samp{#f}.
20201 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
20202 Enable mail process debugging. This can help you figure out why
20203 Dovecot isn't finding your mails.
20204 Defaults to @samp{#f}.
20207 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
20208 Show protocol level SSL errors.
20209 Defaults to @samp{#f}.
20212 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
20213 Prefix for each line written to log file. % codes are in
20214 strftime(3) format.
20215 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
20218 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
20219 List of elements we want to log. The elements which have a
20220 non-empty variable value are joined together to form a comma-separated
20224 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
20225 Login log format. %s contains @samp{login-log-format-elements}
20226 string, %$ contains the data we want to log.
20227 Defaults to @samp{"%$: %s"}.
20230 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
20231 Log prefix for mail processes. See doc/wiki/Variables.txt for list
20232 of possible variables you can use.
20233 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
20236 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
20237 Format to use for logging mail deliveries. You can use variables:
20240 Delivery status message (e.g.@: @samp{saved to INBOX})
20252 Defaults to @samp{"msgid=%m: %$"}.
20255 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
20256 Location for users' mailboxes. The default is empty, which means
20257 that Dovecot tries to find the mailboxes automatically. This won't work
20258 if the user doesn't yet have any mail, so you should explicitly tell
20259 Dovecot the full location.
20261 If you're using mbox, giving a path to the INBOX
20262 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
20263 where the other mailboxes are kept. This is called the @emph{root mail
20264 directory}, and it must be the first path given in the
20265 @samp{mail-location} setting.
20267 There are a few special variables you can use, e.g.:
20273 user part in user@@domain, same as %u if there's no domain
20275 domain part in user@@domain, empty if there's no domain
20280 See doc/wiki/Variables.txt for full list. Some examples:
20282 @item maildir:~/Maildir
20283 @item mbox:~/mail:INBOX=/var/mail/%u
20284 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
20286 Defaults to @samp{""}.
20289 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
20290 System user and group used to access mails. If you use multiple,
20291 userdb can override these by returning uid or gid fields. You can use
20292 either numbers or names. <doc/wiki/UserIds.txt>.
20293 Defaults to @samp{""}.
20296 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
20298 Defaults to @samp{""}.
20301 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
20302 Group to enable temporarily for privileged operations. Currently
20303 this is used only with INBOX when either its initial creation or
20304 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
20306 Defaults to @samp{""}.
20309 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
20310 Grant access to these supplementary groups for mail processes.
20311 Typically these are used to set up access to shared mailboxes. Note
20312 that it may be dangerous to set these if users can create symlinks
20313 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
20314 could allow a user to delete others' mailboxes, or @code{ln -s
20315 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
20319 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
20320 Allow full file system access to clients. There's no access checks
20321 other than what the operating system does for the active UID/GID. It
20322 works with both maildir and mboxes, allowing you to prefix mailboxes
20323 names with e.g.@: @file{/path/} or @file{~user/}.
20324 Defaults to @samp{#f}.
20327 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
20328 Don't use @code{mmap()} at all. This is required if you store indexes to
20329 shared file systems (NFS or clustered file system).
20330 Defaults to @samp{#f}.
20333 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
20334 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
20335 supports @samp{O_EXCL} since version 3, so this should be safe to use
20336 nowadays by default.
20337 Defaults to @samp{#t}.
20340 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
20341 When to use fsync() or fdatasync() calls:
20344 Whenever necessary to avoid losing important data
20346 Useful with e.g.@: NFS when @code{write()}s are delayed
20348 Never use it (best performance, but crashes can lose data).
20350 Defaults to @samp{"optimized"}.
20353 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
20354 Mail storage exists in NFS. Set this to yes to make Dovecot flush
20355 NFS caches whenever needed. If you're using only a single mail server
20357 Defaults to @samp{#f}.
20360 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
20361 Mail index files also exist in NFS. Setting this to yes requires
20362 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
20363 Defaults to @samp{#f}.
20366 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
20367 Locking method for index files. Alternatives are fcntl, flock and
20368 dotlock. Dotlocking uses some tricks which may create more disk I/O
20369 than other locking methods. NFS users: flock doesn't work, remember to
20370 change @samp{mmap-disable}.
20371 Defaults to @samp{"fcntl"}.
20374 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
20375 Directory in which LDA/LMTP temporarily stores incoming mails >128
20377 Defaults to @samp{"/tmp"}.
20380 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
20381 Valid UID range for users. This is mostly to make sure that users can't
20382 log in as daemons or other system users. Note that denying root logins is
20383 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
20385 Defaults to @samp{500}.
20388 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
20390 Defaults to @samp{0}.
20393 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
20394 Valid GID range for users. Users having non-valid GID as primary group ID
20395 aren't allowed to log in. If user belongs to supplementary groups with
20396 non-valid GIDs, those groups are not set.
20397 Defaults to @samp{1}.
20400 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
20402 Defaults to @samp{0}.
20405 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
20406 Maximum allowed length for mail keyword name. It's only forced when
20407 trying to create new keywords.
20408 Defaults to @samp{50}.
20411 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
20412 List of directories under which chrooting is allowed for mail
20413 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
20414 too). This setting doesn't affect @samp{login-chroot}
20415 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
20416 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
20417 which local users can modify, that may lead to root exploit. Usually
20418 this should be done only if you don't allow shell access for users.
20419 <doc/wiki/Chrooting.txt>.
20420 Defaults to @samp{()}.
20423 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
20424 Default chroot directory for mail processes. This can be overridden
20425 for specific users in user database by giving @samp{/./} in user's home
20426 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
20427 there is no real need to do chrooting, Dovecot doesn't allow users to
20428 access files outside their mail directory anyway. If your home
20429 directories are prefixed with the chroot directory, append @samp{/.} to
20430 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
20431 Defaults to @samp{""}.
20434 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
20435 UNIX socket path to master authentication server to find users.
20436 This is used by imap (for shared users) and lda.
20437 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
20440 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
20441 Directory where to look up mail plugins.
20442 Defaults to @samp{"/usr/lib/dovecot"}.
20445 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
20446 List of plugins to load for all services. Plugins specific to IMAP,
20447 LDA, etc.@: are added to this list in their own .conf files.
20448 Defaults to @samp{()}.
20451 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
20452 The minimum number of mails in a mailbox before updates are done to
20453 cache file. This allows optimizing Dovecot's behavior to do less disk
20454 writes at the cost of more disk reads.
20455 Defaults to @samp{0}.
20458 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
20459 When IDLE command is running, mailbox is checked once in a while to
20460 see if there are any new mails or other changes. This setting defines
20461 the minimum time to wait between those checks. Dovecot can also use
20462 dnotify, inotify and kqueue to find out immediately when changes
20464 Defaults to @samp{"30 secs"}.
20467 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
20468 Save mails with CR+LF instead of plain LF. This makes sending those
20469 mails take less CPU, especially with sendfile() syscall with Linux and
20470 FreeBSD. But it also creates a bit more disk I/O which may just make it
20471 slower. Also note that if other software reads the mboxes/maildirs,
20472 they may handle the extra CRs wrong and cause problems.
20473 Defaults to @samp{#f}.
20476 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
20477 By default LIST command returns all entries in maildir beginning
20478 with a dot. Enabling this option makes Dovecot return only entries
20479 which are directories. This is done by stat()ing each entry, so it
20480 causes more disk I/O.
20481 (For systems setting struct @samp{dirent->d_type} this check is free
20482 and it's done always regardless of this setting).
20483 Defaults to @samp{#f}.
20486 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
20487 When copying a message, do it with hard links whenever possible.
20488 This makes the performance much better, and it's unlikely to have any
20490 Defaults to @samp{#t}.
20493 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
20494 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
20495 directory only when its mtime changes unexpectedly or when we can't find
20496 the mail otherwise.
20497 Defaults to @samp{#f}.
20500 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
20501 Which locking methods to use for locking mbox. There are four
20506 Create <mailbox>.lock file. This is the oldest and most NFS-safe
20507 solution. If you want to use /var/mail/ like directory, the users will
20508 need write access to that directory.
20510 Same as dotlock, but if it fails because of permissions or because there
20511 isn't enough disk space, just skip it.
20513 Use this if possible. Works with NFS too if lockd is used.
20515 May not exist in all systems. Doesn't work with NFS.
20517 May not exist in all systems. Doesn't work with NFS.
20520 You can use multiple locking methods; if you do the order they're declared
20521 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
20522 locking methods as well. Some operating systems don't allow using some of
20523 them simultaneously.
20526 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
20530 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
20531 Maximum time to wait for lock (all of them) before aborting.
20532 Defaults to @samp{"5 mins"}.
20535 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
20536 If dotlock exists but the mailbox isn't modified in any way,
20537 override the lock file after this much time.
20538 Defaults to @samp{"2 mins"}.
20541 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
20542 When mbox changes unexpectedly we have to fully read it to find out
20543 what changed. If the mbox is large this can take a long time. Since
20544 the change is usually just a newly appended mail, it'd be faster to
20545 simply read the new mails. If this setting is enabled, Dovecot does
20546 this but still safely fallbacks to re-reading the whole mbox file
20547 whenever something in mbox isn't how it's expected to be. The only real
20548 downside to this setting is that if some other MUA changes message
20549 flags, Dovecot doesn't notice it immediately. Note that a full sync is
20550 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
20551 Defaults to @samp{#t}.
20554 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
20555 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
20556 EXAMINE, EXPUNGE or CHECK commands. If this is set,
20557 @samp{mbox-dirty-syncs} is ignored.
20558 Defaults to @samp{#f}.
20561 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
20562 Delay writing mbox headers until doing a full write sync (EXPUNGE
20563 and CHECK commands and when closing the mailbox). This is especially
20564 useful for POP3 where clients often delete all mails. The downside is
20565 that our changes aren't immediately visible to other MUAs.
20566 Defaults to @samp{#t}.
20569 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
20570 If mbox size is smaller than this (e.g.@: 100k), don't write index
20571 files. If an index file already exists it's still read, just not
20573 Defaults to @samp{0}.
20576 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
20577 Maximum dbox file size until it's rotated.
20578 Defaults to @samp{10000000}.
20581 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
20582 Maximum dbox file age until it's rotated. Typically in days. Day
20583 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
20585 Defaults to @samp{"1d"}.
20588 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
20589 When creating new mdbox files, immediately preallocate their size to
20590 @samp{mdbox-rotate-size}. This setting currently works only in Linux
20591 with some file systems (ext4, xfs).
20592 Defaults to @samp{#f}.
20595 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
20596 sdbox and mdbox support saving mail attachments to external files,
20597 which also allows single instance storage for them. Other backends
20598 don't support this for now.
20600 WARNING: This feature hasn't been tested much yet. Use at your own risk.
20602 Directory root where to store mail attachments. Disabled, if empty.
20603 Defaults to @samp{""}.
20606 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
20607 Attachments smaller than this aren't saved externally. It's also
20608 possible to write a plugin to disable saving specific attachments
20610 Defaults to @samp{128000}.
20613 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
20614 File system backend to use for saving attachments:
20617 No SiS done by Dovecot (but this might help FS's own deduplication)
20619 SiS with immediate byte-by-byte comparison during saving
20620 @item sis-queue posix
20621 SiS with delayed comparison and deduplication.
20623 Defaults to @samp{"sis posix"}.
20626 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
20627 Hash format to use in attachment filenames. You can add any text and
20628 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
20629 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
20630 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
20631 Defaults to @samp{"%@{sha1@}"}.
20634 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
20636 Defaults to @samp{100}.
20639 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
20641 Defaults to @samp{1000}.
20644 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
20645 Default VSZ (virtual memory size) limit for service processes.
20646 This is mainly intended to catch and kill processes that leak memory
20647 before they eat up everything.
20648 Defaults to @samp{256000000}.
20651 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
20652 Login user is internally used by login processes. This is the most
20653 untrusted user in Dovecot system. It shouldn't have access to anything
20655 Defaults to @samp{"dovenull"}.
20658 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
20659 Internal user is used by unprivileged processes. It should be
20660 separate from login user, so that login processes can't disturb other
20662 Defaults to @samp{"dovecot"}.
20665 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
20666 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
20667 Defaults to @samp{"required"}.
20670 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
20671 PEM encoded X.509 SSL/TLS certificate (public key).
20672 Defaults to @samp{"</etc/dovecot/default.pem"}.
20675 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
20676 PEM encoded SSL/TLS private key. The key is opened before
20677 dropping root privileges, so keep the key file unreadable by anyone but
20679 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
20682 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
20683 If key file is password protected, give the password here.
20684 Alternatively give it when starting dovecot with -p parameter. Since
20685 this file is often world-readable, you may want to place this setting
20686 instead to a different.
20687 Defaults to @samp{""}.
20690 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
20691 PEM encoded trusted certificate authority. Set this only if you
20692 intend to use @samp{ssl-verify-client-cert? #t}. The file should
20693 contain the CA certificate(s) followed by the matching
20694 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
20695 Defaults to @samp{""}.
20698 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
20699 Require that CRL check succeeds for client certificates.
20700 Defaults to @samp{#t}.
20703 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
20704 Request client to send a certificate. If you also want to require
20705 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
20706 Defaults to @samp{#f}.
20709 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
20710 Which field from certificate to use for username. commonName and
20711 x500UniqueIdentifier are the usual choices. You'll also need to set
20712 @samp{auth-ssl-username-from-cert? #t}.
20713 Defaults to @samp{"commonName"}.
20716 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
20717 Minimum SSL protocol version to accept.
20718 Defaults to @samp{"TLSv1"}.
20721 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
20722 SSL ciphers to use.
20723 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
20726 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
20727 SSL crypto device to use, for valid values run "openssl engine".
20728 Defaults to @samp{""}.
20731 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
20732 Address to use when sending rejection mails.
20733 %d expands to recipient domain.
20734 Defaults to @samp{"postmaster@@%d"}.
20737 @deftypevr {@code{dovecot-configuration} parameter} string hostname
20738 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
20739 and in LMTP replies. Default is the system's real hostname@@domain.
20740 Defaults to @samp{""}.
20743 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
20744 If user is over quota, return with temporary failure instead of
20746 Defaults to @samp{#f}.
20749 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
20750 Binary to use for sending mails.
20751 Defaults to @samp{"/usr/sbin/sendmail"}.
20754 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
20755 If non-empty, send mails via this SMTP host[:port] instead of
20757 Defaults to @samp{""}.
20760 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
20761 Subject: header to use for rejection mails. You can use the same
20762 variables as for @samp{rejection-reason} below.
20763 Defaults to @samp{"Rejected: %s"}.
20766 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
20767 Human readable error message for rejection mails. You can use
20780 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
20783 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
20784 Delimiter character between local-part and detail in email
20786 Defaults to @samp{"+"}.
20789 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
20790 Header where the original recipient address (SMTP's RCPT TO:
20791 address) is taken from if not available elsewhere. With dovecot-lda -a
20792 parameter overrides this. A commonly used header for this is
20794 Defaults to @samp{""}.
20797 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
20798 Should saving a mail to a nonexistent mailbox automatically create
20800 Defaults to @samp{#f}.
20803 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
20804 Should automatically created mailboxes be also automatically
20806 Defaults to @samp{#f}.
20809 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
20810 Maximum IMAP command line length. Some clients generate very long
20811 command lines with huge mailboxes, so you may need to raise this if you
20812 get "Too long argument" or "IMAP command line too large" errors
20814 Defaults to @samp{64000}.
20817 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
20818 IMAP logout format string:
20821 total number of bytes read from client
20823 total number of bytes sent to client.
20825 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
20826 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@}"}.
20829 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
20830 Override the IMAP CAPABILITY response. If the value begins with '+',
20831 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
20832 Defaults to @samp{""}.
20835 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
20836 How long to wait between "OK Still here" notifications when client
20838 Defaults to @samp{"2 mins"}.
20841 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
20842 ID field names and values to send to clients. Using * as the value
20843 makes Dovecot use the default value. The following fields have default
20844 values currently: name, version, os, os-version, support-url,
20846 Defaults to @samp{""}.
20849 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
20850 ID fields sent by client to log. * means everything.
20851 Defaults to @samp{""}.
20854 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
20855 Workarounds for various client bugs:
20858 @item delay-newmail
20859 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
20860 CHECK commands. Some clients ignore them otherwise, for example OSX
20861 Mail (<v2.1). Outlook Express breaks more badly though, without this it
20862 may show user "Message no longer in server" errors. Note that OE6
20863 still breaks even with this workaround if synchronization is set to
20866 @item tb-extra-mailbox-sep
20867 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
20868 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
20869 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
20871 @item tb-lsub-flags
20872 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
20873 This makes Thunderbird realize they aren't selectable and show them
20874 greyed out, instead of only later giving "not selectable" popup error.
20876 Defaults to @samp{()}.
20879 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
20880 Host allowed in URLAUTH URLs sent by client. "*" allows all.
20881 Defaults to @samp{""}.
20885 Whew! Lots of configuration options. The nice thing about it though is
20886 that Guix has a complete interface to Dovecot's configuration
20887 language. This allows not only a nice way to declare configurations,
20888 but also offers reflective capabilities as well: users can write code to
20889 inspect and transform configurations from within Scheme.
20891 However, it could be that you just want to get a @code{dovecot.conf} up
20892 and running. In that case, you can pass an
20893 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
20894 @code{dovecot-service}. As its name indicates, an opaque configuration
20895 does not have easy reflective capabilities.
20897 Available @code{opaque-dovecot-configuration} fields are:
20899 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
20900 The dovecot package.
20903 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
20904 The contents of the @code{dovecot.conf}, as a string.
20907 For example, if your @code{dovecot.conf} is just the empty string, you
20908 could instantiate a dovecot service like this:
20911 (dovecot-service #:config
20912 (opaque-dovecot-configuration
20916 @subsubheading OpenSMTPD Service
20918 @deffn {Scheme Variable} opensmtpd-service-type
20919 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
20920 service, whose value should be an @code{opensmtpd-configuration} object
20921 as in this example:
20924 (service opensmtpd-service-type
20925 (opensmtpd-configuration
20926 (config-file (local-file "./my-smtpd.conf"))))
20930 @deftp {Data Type} opensmtpd-configuration
20931 Data type representing the configuration of opensmtpd.
20934 @item @code{package} (default: @var{opensmtpd})
20935 Package object of the OpenSMTPD SMTP server.
20937 @item @code{config-file} (default: @code{%default-opensmtpd-file})
20938 File-like object of the OpenSMTPD configuration file to use. By default
20939 it listens on the loopback network interface, and allows for mail from
20940 users and daemons on the local machine, as well as permitting email to
20941 remote servers. Run @command{man smtpd.conf} for more information.
20946 @subsubheading Exim Service
20948 @cindex mail transfer agent (MTA)
20949 @cindex MTA (mail transfer agent)
20952 @deffn {Scheme Variable} exim-service-type
20953 This is the type of the @uref{https://exim.org, Exim} mail transfer
20954 agent (MTA), whose value should be an @code{exim-configuration} object
20955 as in this example:
20958 (service exim-service-type
20959 (exim-configuration
20960 (config-file (local-file "./my-exim.conf"))))
20964 In order to use an @code{exim-service-type} service you must also have a
20965 @code{mail-aliases-service-type} service present in your
20966 @code{operating-system} (even if it has no aliases).
20968 @deftp {Data Type} exim-configuration
20969 Data type representing the configuration of exim.
20972 @item @code{package} (default: @var{exim})
20973 Package object of the Exim server.
20975 @item @code{config-file} (default: @code{#f})
20976 File-like object of the Exim configuration file to use. If its value is
20977 @code{#f} then use the default configuration file from the package
20978 provided in @code{package}. The resulting configuration file is loaded
20979 after setting the @code{exim_user} and @code{exim_group} configuration
20985 @subsubheading Getmail service
20990 @deffn {Scheme Variable} getmail-service-type
20991 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
20992 mail retriever, whose value should be an @code{getmail-configuration}.
20995 Available @code{getmail-configuration} fields are:
20997 @deftypevr {@code{getmail-configuration} parameter} symbol name
20998 A symbol to identify the getmail service.
21000 Defaults to @samp{"unset"}.
21004 @deftypevr {@code{getmail-configuration} parameter} package package
21005 The getmail package to use.
21009 @deftypevr {@code{getmail-configuration} parameter} string user
21010 The user to run getmail as.
21012 Defaults to @samp{"getmail"}.
21016 @deftypevr {@code{getmail-configuration} parameter} string group
21017 The group to run getmail as.
21019 Defaults to @samp{"getmail"}.
21023 @deftypevr {@code{getmail-configuration} parameter} string directory
21024 The getmail directory to use.
21026 Defaults to @samp{"/var/lib/getmail/default"}.
21030 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
21031 The getmail configuration file to use.
21033 Available @code{getmail-configuration-file} fields are:
21035 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
21036 What mail account to retrieve mail from, and how to access that account.
21038 Available @code{getmail-retriever-configuration} fields are:
21040 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
21041 The type of mail retriever to use. Valid values include @samp{passwd}
21044 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
21048 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
21049 Username to login to the mail server with.
21051 Defaults to @samp{unset}.
21055 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
21056 Username to login to the mail server with.
21058 Defaults to @samp{unset}.
21062 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
21063 Port number to connect to.
21065 Defaults to @samp{#f}.
21069 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
21070 Override fields from passwd.
21072 Defaults to @samp{""}.
21076 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
21077 Override fields from passwd.
21079 Defaults to @samp{()}.
21083 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
21084 PEM-formatted key file to use for the TLS negotiation.
21086 Defaults to @samp{""}.
21090 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
21091 PEM-formatted certificate file to use for the TLS negotiation.
21093 Defaults to @samp{""}.
21097 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
21098 CA certificates to use.
21100 Defaults to @samp{""}.
21104 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
21105 Extra retriever parameters.
21107 Defaults to @samp{()}.
21113 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
21114 What to do with retrieved messages.
21116 Available @code{getmail-destination-configuration} fields are:
21118 @deftypevr {@code{getmail-destination-configuration} parameter} string type
21119 The type of mail destination. Valid values include @samp{Maildir},
21120 @samp{Mboxrd} and @samp{MDA_external}.
21122 Defaults to @samp{unset}.
21126 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
21127 The path option for the mail destination. The behaviour depends on the
21130 Defaults to @samp{""}.
21134 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
21135 Extra destination parameters
21137 Defaults to @samp{()}.
21143 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
21146 Available @code{getmail-options-configuration} fields are:
21148 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
21149 If set to @samp{0}, getmail will only print warnings and errors. A
21150 value of @samp{1} means that messages will be printed about retrieving
21151 and deleting messages. If set to @samp{2}, getmail will print messages
21152 about each of it's actions.
21154 Defaults to @samp{1}.
21158 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
21159 If true, getmail will retrieve all available messages. Otherwise it
21160 will only retrieve messages it hasn't seen previously.
21162 Defaults to @samp{#t}.
21166 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
21167 If set to true, messages will be deleted from the server after
21168 retrieving and successfully delivering them. Otherwise, messages will
21169 be left on the server.
21171 Defaults to @samp{#f}.
21175 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
21176 Getmail will delete messages this number of days after seeing them, if
21177 they have been delivered. This means messages will be left on the
21178 server this number of days after delivering them. A value of @samp{0}
21179 disabled this feature.
21181 Defaults to @samp{0}.
21185 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
21186 Delete messages larger than this of bytes after retrieving them, even if
21187 the delete and delete-after options are disabled. A value of @samp{0}
21188 disables this feature.
21190 Defaults to @samp{0}.
21194 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
21195 Retrieve messages totalling up to this number of bytes before closing
21196 the session with the server. A value of @samp{0} disables this feature.
21198 Defaults to @samp{0}.
21202 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
21203 Don't retrieve messages larger than this number of bytes. A value of
21204 @samp{0} disables this feature.
21206 Defaults to @samp{0}.
21210 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
21211 If true, getmail will add a Delivered-To header to messages.
21213 Defaults to @samp{#t}.
21217 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
21218 If set, getmail adds a Received header to the messages.
21220 Defaults to @samp{#t}.
21224 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
21225 Getmail will record a log of its actions to the named file. A value of
21226 @samp{""} disables this feature.
21228 Defaults to @samp{""}.
21232 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
21233 If true, getmail will record a log of its actions using the system
21236 Defaults to @samp{#f}.
21240 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
21241 If true, getmail will log information about messages not retrieved and
21242 the reason for not retrieving them, as well as starting and ending
21245 Defaults to @samp{#f}.
21249 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
21250 Extra options to include.
21252 Defaults to @samp{()}.
21260 @deftypevr {@code{getmail-configuration} parameter} list idle
21261 A list of mailboxes that getmail should wait on the server for new mail
21262 notifications. This depends on the server supporting the IDLE
21265 Defaults to @samp{()}.
21269 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
21270 Environment variables to set for getmail.
21272 Defaults to @samp{()}.
21276 @subsubheading Mail Aliases Service
21278 @cindex email aliases
21279 @cindex aliases, for email addresses
21281 @deffn {Scheme Variable} mail-aliases-service-type
21282 This is the type of the service which provides @code{/etc/aliases},
21283 specifying how to deliver mail to users on this system.
21286 (service mail-aliases-service-type
21287 '(("postmaster" "bob")
21288 ("bob" "bob@@example.com" "bob@@example2.com")))
21292 The configuration for a @code{mail-aliases-service-type} service is an
21293 association list denoting how to deliver mail that comes to this
21294 system. Each entry is of the form @code{(alias addresses ...)}, with
21295 @code{alias} specifying the local alias and @code{addresses} specifying
21296 where to deliver this user's mail.
21298 The aliases aren't required to exist as users on the local system. In
21299 the above example, there doesn't need to be a @code{postmaster} entry in
21300 the @code{operating-system}'s @code{user-accounts} in order to deliver
21301 the @code{postmaster} mail to @code{bob} (which subsequently would
21302 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
21304 @subsubheading GNU Mailutils IMAP4 Daemon
21305 @cindex GNU Mailutils IMAP4 Daemon
21307 @deffn {Scheme Variable} imap4d-service-type
21308 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
21309 mailutils, GNU Mailutils Manual}), whose value should be an
21310 @code{imap4d-configuration} object as in this example:
21313 (service imap4d-service-type
21314 (imap4d-configuration
21315 (config-file (local-file "imap4d.conf"))))
21319 @deftp {Data Type} imap4d-configuration
21320 Data type representing the configuration of @command{imap4d}.
21323 @item @code{package} (default: @code{mailutils})
21324 The package that provides @command{imap4d}.
21326 @item @code{config-file} (default: @code{%default-imap4d-config-file})
21327 File-like object of the configuration file to use, by default it will listen
21328 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
21329 Mailutils Manual}, for details.
21334 @subsubheading Radicale Service
21338 @deffn {Scheme Variable} radicale-service-type
21339 This is the type of the @uref{https://radicale.org, Radicale} CalDAV/CardDAV
21340 server whose value should be a @code{radicale-configuration}.
21343 @deftp {Data Type} radicale-configuration
21344 Data type representing the configuration of @command{radicale}.
21347 @item @code{package} (default: @code{radicale})
21348 The package that provides @command{radicale}.
21350 @item @code{config-file} (default: @code{%default-radicale-config-file})
21351 File-like object of the configuration file to use, by default it will listen
21352 on TCP port 5232 of @code{localhost} and use the @code{htpasswd} file at
21353 @file{/var/lib/radicale/users} with no (@code{plain}) encryption.
21358 @node Messaging Services
21359 @subsection Messaging Services
21364 The @code{(gnu services messaging)} module provides Guix service
21365 definitions for messaging services. Currently it provides the following
21368 @subsubheading Prosody Service
21370 @deffn {Scheme Variable} prosody-service-type
21371 This is the type for the @uref{https://prosody.im, Prosody XMPP
21372 communication server}. Its value must be a @code{prosody-configuration}
21373 record as in this example:
21376 (service prosody-service-type
21377 (prosody-configuration
21378 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
21381 (int-component-configuration
21382 (hostname "conference.example.net")
21384 (mod-muc (mod-muc-configuration)))))
21387 (virtualhost-configuration
21388 (domain "example.net"))))))
21391 See below for details about @code{prosody-configuration}.
21395 By default, Prosody does not need much configuration. Only one
21396 @code{virtualhosts} field is needed: it specifies the domain you wish
21399 You can perform various sanity checks on the generated configuration
21400 with the @code{prosodyctl check} command.
21402 Prosodyctl will also help you to import certificates from the
21403 @code{letsencrypt} directory so that the @code{prosody} user can access
21404 them. See @url{https://prosody.im/doc/letsencrypt}.
21407 prosodyctl --root cert import /etc/letsencrypt/live
21410 The available configuration parameters follow. Each parameter
21411 definition is preceded by its type; for example, @samp{string-list foo}
21412 indicates that the @code{foo} parameter should be specified as a list of
21413 strings. Types starting with @code{maybe-} denote parameters that won't
21414 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
21416 There is also a way to specify the configuration as a string, if you
21417 have an old @code{prosody.cfg.lua} file that you want to port over from
21418 some other system; see the end for more details.
21420 The @code{file-object} type designates either a file-like object
21421 (@pxref{G-Expressions, file-like objects}) or a file name.
21423 @c The following documentation was initially generated by
21424 @c (generate-documentation) in (gnu services messaging). Manually maintained
21425 @c documentation is better, so we shouldn't hesitate to edit below as
21426 @c needed. However if the change you want to make to this documentation
21427 @c can be done in an automated way, it's probably easier to change
21428 @c (generate-documentation) than to make it below and have to deal with
21429 @c the churn as Prosody updates.
21431 Available @code{prosody-configuration} fields are:
21433 @deftypevr {@code{prosody-configuration} parameter} package prosody
21434 The Prosody package.
21437 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
21438 Location of the Prosody data storage directory. See
21439 @url{https://prosody.im/doc/configure}.
21440 Defaults to @samp{"/var/lib/prosody"}.
21443 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
21444 Additional plugin directories. They are searched in all the specified
21445 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
21446 Defaults to @samp{()}.
21449 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
21450 Every virtual host and component needs a certificate so that clients and
21451 servers can securely verify its identity. Prosody will automatically load
21452 certificates/keys from the directory specified here.
21453 Defaults to @samp{"/etc/prosody/certs"}.
21456 @deftypevr {@code{prosody-configuration} parameter} string-list admins
21457 This is a list of accounts that are admins for the server. Note that you
21458 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
21459 @url{https://prosody.im/doc/creating_accounts}.
21460 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
21461 Defaults to @samp{()}.
21464 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
21465 Enable use of libevent for better performance under high load. See
21466 @url{https://prosody.im/doc/libevent}.
21467 Defaults to @samp{#f}.
21470 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
21471 This is the list of modules Prosody will load on startup. It looks for
21472 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
21473 Documentation on modules can be found at:
21474 @url{https://prosody.im/doc/modules}.
21475 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
21478 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
21479 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
21480 should you want to disable them then add them to this list.
21481 Defaults to @samp{()}.
21484 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
21485 Path to a text file where the shared groups are defined. If this path is
21486 empty then @samp{mod_groups} does nothing. See
21487 @url{https://prosody.im/doc/modules/mod_groups}.
21488 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
21491 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
21492 Disable account creation by default, for security. See
21493 @url{https://prosody.im/doc/creating_accounts}.
21494 Defaults to @samp{#f}.
21497 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
21498 These are the SSL/TLS-related settings. Most of them are disabled so to
21499 use Prosody's defaults. If you do not completely understand these options, do
21500 not add them to your config, it is easy to lower the security of your server
21501 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
21503 Available @code{ssl-configuration} fields are:
21505 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
21506 This determines what handshake to use.
21509 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
21510 Path to your private key file.
21513 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
21514 Path to your certificate file.
21517 @deftypevr {@code{ssl-configuration} parameter} file-object capath
21518 Path to directory containing root certificates that you wish Prosody to
21519 trust when verifying the certificates of remote servers.
21520 Defaults to @samp{"/etc/ssl/certs"}.
21523 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
21524 Path to a file containing root certificates that you wish Prosody to trust.
21525 Similar to @code{capath} but with all certificates concatenated together.
21528 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
21529 A list of verification options (these mostly map to OpenSSL's
21530 @code{set_verify()} flags).
21533 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
21534 A list of general options relating to SSL/TLS. These map to OpenSSL's
21535 @code{set_options()}. For a full list of options available in LuaSec, see the
21539 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
21540 How long a chain of certificate authorities to check when looking for a
21541 trusted root certificate.
21544 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
21545 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
21546 clients, and in what order.
21549 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
21550 A path to a file containing parameters for Diffie-Hellman key exchange. You
21551 can create such a file with:
21552 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
21555 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
21556 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
21557 @samp{"secp384r1"}.
21560 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
21561 A list of ``extra'' verification options.
21564 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
21565 Password for encrypted private keys.
21570 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
21571 Whether to force all client-to-server connections to be encrypted or not.
21572 See @url{https://prosody.im/doc/modules/mod_tls}.
21573 Defaults to @samp{#f}.
21576 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
21577 Set of mechanisms that will never be offered. See
21578 @url{https://prosody.im/doc/modules/mod_saslauth}.
21579 Defaults to @samp{("DIGEST-MD5")}.
21582 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
21583 Whether to force all server-to-server connections to be encrypted or not.
21584 See @url{https://prosody.im/doc/modules/mod_tls}.
21585 Defaults to @samp{#f}.
21588 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
21589 Whether to require encryption and certificate authentication. This
21590 provides ideal security, but requires servers you communicate with to support
21591 encryption AND present valid, trusted certificates. See
21592 @url{https://prosody.im/doc/s2s#security}.
21593 Defaults to @samp{#f}.
21596 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
21597 Many servers don't support encryption or have invalid or self-signed
21598 certificates. You can list domains here that will not be required to
21599 authenticate using certificates. They will be authenticated using DNS. See
21600 @url{https://prosody.im/doc/s2s#security}.
21601 Defaults to @samp{()}.
21604 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
21605 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
21606 valid certificates for some domains by specifying a list here. See
21607 @url{https://prosody.im/doc/s2s#security}.
21608 Defaults to @samp{()}.
21611 @deftypevr {@code{prosody-configuration} parameter} string authentication
21612 Select the authentication backend to use. The default provider stores
21613 passwords in plaintext and uses Prosody's configured data storage to store the
21614 authentication data. If you do not trust your server please see
21615 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
21616 about using the hashed backend. See also
21617 @url{https://prosody.im/doc/authentication}
21618 Defaults to @samp{"internal_plain"}.
21621 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
21622 Set logging options. Advanced logging configuration is not yet supported
21623 by the Prosody service. See @url{https://prosody.im/doc/logging}.
21624 Defaults to @samp{"*syslog"}.
21627 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
21628 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
21629 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
21632 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
21633 Maximum allowed size of the HTTP body (in bytes).
21636 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
21637 Some modules expose their own URL in various ways. This URL is built
21638 from the protocol, host and port used. If Prosody sits behind a proxy, the
21639 public URL will be @code{http-external-url} instead. See
21640 @url{https://prosody.im/doc/http#external_url}.
21643 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
21644 A host in Prosody is a domain on which user accounts can be created. For
21645 example if you want your users to have addresses like
21646 @samp{"john.smith@@example.com"} then you need to add a host
21647 @samp{"example.com"}. All options in this list will apply only to this host.
21649 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
21650 the actual physical host that Prosody is installed on. A single Prosody
21651 instance can serve many domains, each one defined as a VirtualHost entry in
21652 Prosody's configuration. Conversely a server that hosts a single domain would
21653 have just one VirtualHost entry.
21655 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
21657 Available @code{virtualhost-configuration} fields are:
21659 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:
21660 @deftypevr {@code{virtualhost-configuration} parameter} string domain
21661 Domain you wish Prosody to serve.
21666 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
21667 Components are extra services on a server which are available to clients,
21668 usually on a subdomain of the main server (such as
21669 @samp{"mycomponent.example.com"}). Example components might be chatroom
21670 servers, user directories, or gateways to other protocols.
21672 Internal components are implemented with Prosody-specific plugins. To add an
21673 internal component, you simply fill the hostname field, and the plugin you wish
21674 to use for the component.
21676 See @url{https://prosody.im/doc/components}.
21677 Defaults to @samp{()}.
21679 Available @code{int-component-configuration} fields are:
21681 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:
21682 @deftypevr {@code{int-component-configuration} parameter} string hostname
21683 Hostname of the component.
21686 @deftypevr {@code{int-component-configuration} parameter} string plugin
21687 Plugin you wish to use for the component.
21690 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
21691 Multi-user chat (MUC) is Prosody's module for allowing you to create
21692 hosted chatrooms/conferences for XMPP users.
21694 General information on setting up and using multi-user chatrooms can be found
21695 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
21696 which you should read if you are new to XMPP chatrooms.
21698 See also @url{https://prosody.im/doc/modules/mod_muc}.
21700 Available @code{mod-muc-configuration} fields are:
21702 @deftypevr {@code{mod-muc-configuration} parameter} string name
21703 The name to return in service discovery responses.
21704 Defaults to @samp{"Prosody Chatrooms"}.
21707 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
21708 If @samp{#t}, this will only allow admins to create new chatrooms.
21709 Otherwise anyone can create a room. The value @samp{"local"} restricts room
21710 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
21711 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
21712 restricts to service administrators only.
21713 Defaults to @samp{#f}.
21716 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
21717 Maximum number of history messages that will be sent to the member that has
21718 just joined the room.
21719 Defaults to @samp{20}.
21726 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
21727 External components use XEP-0114, which most standalone components
21728 support. To add an external component, you simply fill the hostname field. See
21729 @url{https://prosody.im/doc/components}.
21730 Defaults to @samp{()}.
21732 Available @code{ext-component-configuration} fields are:
21734 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:
21735 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
21736 Password which the component will use to log in.
21739 @deftypevr {@code{ext-component-configuration} parameter} string hostname
21740 Hostname of the component.
21745 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
21746 Port(s) Prosody listens on for component connections.
21747 Defaults to @samp{(5347)}.
21750 @deftypevr {@code{prosody-configuration} parameter} string component-interface
21751 Interface Prosody listens on for component connections.
21752 Defaults to @samp{"127.0.0.1"}.
21755 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
21756 Raw content that will be added to the configuration file.
21759 It could be that you just want to get a @code{prosody.cfg.lua}
21760 up and running. In that case, you can pass an
21761 @code{opaque-prosody-configuration} record as the value of
21762 @code{prosody-service-type}. As its name indicates, an opaque configuration
21763 does not have easy reflective capabilities.
21764 Available @code{opaque-prosody-configuration} fields are:
21766 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
21767 The prosody package.
21770 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
21771 The contents of the @code{prosody.cfg.lua} to use.
21774 For example, if your @code{prosody.cfg.lua} is just the empty
21775 string, you could instantiate a prosody service like this:
21778 (service prosody-service-type
21779 (opaque-prosody-configuration
21780 (prosody.cfg.lua "")))
21783 @c end of Prosody auto-generated documentation
21785 @subsubheading BitlBee Service
21787 @cindex IRC (Internet Relay Chat)
21788 @cindex IRC gateway
21789 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
21790 interface to a variety of messaging protocols such as XMPP.
21792 @defvr {Scheme Variable} bitlbee-service-type
21793 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
21794 gateway daemon. Its value is a @code{bitlbee-configuration} (see
21797 To have BitlBee listen on port 6667 on localhost, add this line to your
21801 (service bitlbee-service-type)
21805 @deftp {Data Type} bitlbee-configuration
21806 This is the configuration for BitlBee, with the following fields:
21809 @item @code{interface} (default: @code{"127.0.0.1"})
21810 @itemx @code{port} (default: @code{6667})
21811 Listen on the network interface corresponding to the IP address
21812 specified in @var{interface}, on @var{port}.
21814 When @var{interface} is @code{127.0.0.1}, only local clients can
21815 connect; when it is @code{0.0.0.0}, connections can come from any
21816 networking interface.
21818 @item @code{bitlbee} (default: @code{bitlbee})
21819 The BitlBee package to use.
21821 @item @code{plugins} (default: @code{'()})
21822 List of plugin packages to use---e.g., @code{bitlbee-discord}.
21824 @item @code{extra-settings} (default: @code{""})
21825 Configuration snippet added as-is to the BitlBee configuration file.
21829 @subsubheading Quassel Service
21831 @cindex IRC (Internet Relay Chat)
21832 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
21833 meaning that one or more clients can attach to and detach from the
21836 @defvr {Scheme Variable} quassel-service-type
21837 This is the service type for the @url{https://quassel-irc.org/,Quassel}
21838 IRC backend daemon. Its value is a @code{quassel-configuration}
21842 @deftp {Data Type} quassel-configuration
21843 This is the configuration for Quassel, with the following fields:
21846 @item @code{quassel} (default: @code{quassel})
21847 The Quassel package to use.
21849 @item @code{interface} (default: @code{"::,0.0.0.0"})
21850 @item @code{port} (default: @code{4242})
21851 Listen on the network interface(s) corresponding to the IPv4 or IPv6
21852 interfaces specified in the comma delimited @var{interface}, on
21855 @item @code{loglevel} (default: @code{"Info"})
21856 The level of logging desired. Accepted values are Debug, Info, Warning
21861 @node Telephony Services
21862 @subsection Telephony Services
21864 @cindex Murmur (VoIP server)
21865 @cindex VoIP server
21866 This section describes how to set up and run a Murmur server. Murmur is
21867 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
21870 @deftp {Data Type} murmur-configuration
21871 The service type for the Murmur server. An example configuration can
21875 (service murmur-service-type
21876 (murmur-configuration
21878 "Welcome to this Mumble server running on Guix!")
21879 (cert-required? #t) ;disallow text password logins
21880 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
21881 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
21884 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
21885 password with the command that is printed during the activation phase.
21887 It is recommended to register a normal Mumble user account
21888 and grant it admin or moderator rights.
21889 You can use the @code{mumble} client to
21890 login as new normal user, register yourself, and log out.
21891 For the next step login with the name @code{SuperUser} use
21892 the @code{SuperUser} password that you set previously,
21893 and grant your newly registered mumble user administrator or moderator
21894 rights and create some channels.
21896 Available @code{murmur-configuration} fields are:
21899 @item @code{package} (default: @code{mumble})
21900 Package that contains @code{bin/murmurd}.
21902 @item @code{user} (default: @code{"murmur"})
21903 User who will run the Murmur server.
21905 @item @code{group} (default: @code{"murmur"})
21906 Group of the user who will run the murmur server.
21908 @item @code{port} (default: @code{64738})
21909 Port on which the server will listen.
21911 @item @code{welcome-text} (default: @code{""})
21912 Welcome text sent to clients when they connect.
21914 @item @code{server-password} (default: @code{""})
21915 Password the clients have to enter in order to connect.
21917 @item @code{max-users} (default: @code{100})
21918 Maximum of users that can be connected to the server at once.
21920 @item @code{max-user-bandwidth} (default: @code{#f})
21921 Maximum voice traffic a user can send per second.
21923 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
21924 File name of the sqlite database.
21925 The service's user will become the owner of the directory.
21927 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
21928 File name of the log file.
21929 The service's user will become the owner of the directory.
21931 @item @code{autoban-attempts} (default: @code{10})
21932 Maximum number of logins a user can make in @code{autoban-timeframe}
21933 without getting auto banned for @code{autoban-time}.
21935 @item @code{autoban-timeframe} (default: @code{120})
21936 Timeframe for autoban in seconds.
21938 @item @code{autoban-time} (default: @code{300})
21939 Amount of time in seconds for which a client gets banned
21940 when violating the autoban limits.
21942 @item @code{opus-threshold} (default: @code{100})
21943 Percentage of clients that need to support opus
21944 before switching over to opus audio codec.
21946 @item @code{channel-nesting-limit} (default: @code{10})
21947 How deep channels can be nested at maximum.
21949 @item @code{channelname-regex} (default: @code{#f})
21950 A string in form of a Qt regular expression that channel names must conform to.
21952 @item @code{username-regex} (default: @code{#f})
21953 A string in form of a Qt regular expression that user names must conform to.
21955 @item @code{text-message-length} (default: @code{5000})
21956 Maximum size in bytes that a user can send in one text chat message.
21958 @item @code{image-message-length} (default: @code{(* 128 1024)})
21959 Maximum size in bytes that a user can send in one image message.
21961 @item @code{cert-required?} (default: @code{#f})
21962 If it is set to @code{#t} clients that use weak password authentication
21963 will not be accepted. Users must have completed the certificate wizard to join.
21965 @item @code{remember-channel?} (default: @code{#f})
21966 Should murmur remember the last channel each user was in when they disconnected
21967 and put them into the remembered channel when they rejoin.
21969 @item @code{allow-html?} (default: @code{#f})
21970 Should html be allowed in text messages, user comments, and channel descriptions.
21972 @item @code{allow-ping?} (default: @code{#f})
21973 Setting to true exposes the current user count, the maximum user count, and
21974 the server's maximum bandwidth per client to unauthenticated users. In the
21975 Mumble client, this information is shown in the Connect dialog.
21977 Disabling this setting will prevent public listing of the server.
21979 @item @code{bonjour?} (default: @code{#f})
21980 Should the server advertise itself in the local network through the bonjour protocol.
21982 @item @code{send-version?} (default: @code{#f})
21983 Should the murmur server version be exposed in ping requests.
21985 @item @code{log-days} (default: @code{31})
21986 Murmur also stores logs in the database, which are accessible via RPC.
21987 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
21988 or -1 to disable logging to the database.
21990 @item @code{obfuscate-ips?} (default: @code{#t})
21991 Should logged ips be obfuscated to protect the privacy of users.
21993 @item @code{ssl-cert} (default: @code{#f})
21994 File name of the SSL/TLS certificate used for encrypted connections.
21997 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
21999 @item @code{ssl-key} (default: @code{#f})
22000 Filepath to the ssl private key used for encrypted connections.
22002 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
22005 @item @code{ssl-dh-params} (default: @code{#f})
22006 File name of a PEM-encoded file with Diffie-Hellman parameters
22007 for the SSL/TLS encryption. Alternatively you set it to
22008 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
22009 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
22011 @item @code{ssl-ciphers} (default: @code{#f})
22012 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
22015 This option is specified using
22016 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
22017 OpenSSL cipher list notation}.
22019 It is recommended that you try your cipher string using 'openssl ciphers <string>'
22020 before setting it here, to get a feel for which cipher suites you will get.
22021 After setting this option, it is recommend that you inspect your Murmur log
22022 to ensure that Murmur is using the cipher suites that you expected it to.
22024 Note: Changing this option may impact the backwards compatibility of your
22025 Murmur server, and can remove the ability for older Mumble clients to be able
22028 @item @code{public-registration} (default: @code{#f})
22029 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
22031 You can optionally register your server in the public server list that the
22032 @code{mumble} client shows on startup.
22033 You cannot register your server if you have set a @code{server-password},
22034 or set @code{allow-ping} to @code{#f}.
22036 It might take a few hours until it shows up in the public list.
22038 @item @code{file} (default: @code{#f})
22039 Optional alternative override for this configuration.
22043 @deftp {Data Type} murmur-public-registration-configuration
22044 Configuration for public registration of a murmur service.
22048 This is a display name for your server. Not to be confused with the hostname.
22050 @item @code{password}
22051 A password to identify your registration.
22052 Subsequent updates will need the same password. Don't lose your password.
22055 This should be a @code{http://} or @code{https://} link to your web
22058 @item @code{hostname} (default: @code{#f})
22059 By default your server will be listed by its IP address.
22060 If it is set your server will be linked by this host name instead.
22066 @node Monitoring Services
22067 @subsection Monitoring Services
22069 @subsubheading Tailon Service
22071 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
22072 viewing and searching log files.
22074 The following example will configure the service with default values.
22075 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
22078 (service tailon-service-type)
22081 The following example customises more of the Tailon configuration,
22082 adding @command{sed} to the list of allowed commands.
22085 (service tailon-service-type
22086 (tailon-configuration
22088 (tailon-configuration-file
22089 (allowed-commands '("tail" "grep" "awk" "sed"))))))
22093 @deftp {Data Type} tailon-configuration
22094 Data type representing the configuration of Tailon.
22095 This type has the following parameters:
22098 @item @code{config-file} (default: @code{(tailon-configuration-file)})
22099 The configuration file to use for Tailon. This can be set to a
22100 @dfn{tailon-configuration-file} record value, or any gexp
22101 (@pxref{G-Expressions}).
22103 For example, to instead use a local file, the @code{local-file} function
22107 (service tailon-service-type
22108 (tailon-configuration
22109 (config-file (local-file "./my-tailon.conf"))))
22112 @item @code{package} (default: @code{tailon})
22113 The tailon package to use.
22118 @deftp {Data Type} tailon-configuration-file
22119 Data type representing the configuration options for Tailon.
22120 This type has the following parameters:
22123 @item @code{files} (default: @code{(list "/var/log")})
22124 List of files to display. The list can include strings for a single file
22125 or directory, or a list, where the first item is the name of a
22126 subsection, and the remaining items are the files or directories in that
22129 @item @code{bind} (default: @code{"localhost:8080"})
22130 Address and port to which Tailon should bind on.
22132 @item @code{relative-root} (default: @code{#f})
22133 URL path to use for Tailon, set to @code{#f} to not use a path.
22135 @item @code{allow-transfers?} (default: @code{#t})
22136 Allow downloading the log files in the web interface.
22138 @item @code{follow-names?} (default: @code{#t})
22139 Allow tailing of not-yet existent files.
22141 @item @code{tail-lines} (default: @code{200})
22142 Number of lines to read initially from each file.
22144 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
22145 Commands to allow running. By default, @code{sed} is disabled.
22147 @item @code{debug?} (default: @code{#f})
22148 Set @code{debug?} to @code{#t} to show debug messages.
22150 @item @code{wrap-lines} (default: @code{#t})
22151 Initial line wrapping state in the web interface. Set to @code{#t} to
22152 initially wrap lines (the default), or to @code{#f} to initially not
22155 @item @code{http-auth} (default: @code{#f})
22156 HTTP authentication type to use. Set to @code{#f} to disable
22157 authentication (the default). Supported values are @code{"digest"} or
22160 @item @code{users} (default: @code{#f})
22161 If HTTP authentication is enabled (see @code{http-auth}), access will be
22162 restricted to the credentials provided here. To configure users, use a
22163 list of pairs, where the first element of the pair is the username, and
22164 the 2nd element of the pair is the password.
22167 (tailon-configuration-file
22168 (http-auth "basic")
22169 (users '(("user1" . "password1")
22170 ("user2" . "password2"))))
22177 @subsubheading Darkstat Service
22179 Darkstat is a packet sniffer that captures network traffic, calculates
22180 statistics about usage, and serves reports over HTTP.
22182 @defvar {Scheme Variable} darkstat-service-type
22183 This is the service type for the
22184 @uref{https://unix4lyfe.org/darkstat/, darkstat}
22185 service, its value must be a @code{darkstat-configuration} record as in
22189 (service darkstat-service-type
22190 (darkstat-configuration
22191 (interface "eno1")))
22195 @deftp {Data Type} darkstat-configuration
22196 Data type representing the configuration of @command{darkstat}.
22199 @item @code{package} (default: @code{darkstat})
22200 The darkstat package to use.
22202 @item @code{interface}
22203 Capture traffic on the specified network interface.
22205 @item @code{port} (default: @code{"667"})
22206 Bind the web interface to the specified port.
22208 @item @code{bind-address} (default: @code{"127.0.0.1"})
22209 Bind the web interface to the specified address.
22211 @item @code{base} (default: @code{"/"})
22212 Specify the path of the base URL. This can be useful if
22213 @command{darkstat} is accessed via a reverse proxy.
22218 @subsubheading Prometheus Node Exporter Service
22220 @cindex prometheus-node-exporter
22221 The Prometheus ``node exporter'' makes hardware and operating system statistics
22222 provided by the Linux kernel available for the Prometheus monitoring system.
22223 This service should be deployed on all physical nodes and virtual machines,
22224 where monitoring these statistics is desirable.
22226 @defvar {Scheme variable} prometheus-node-exporter-service-type
22227 This is the service type for the
22228 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
22229 service, its value must be a @code{prometheus-node-exporter-configuration}.
22232 (service prometheus-node-exporter-service-type)
22236 @deftp {Data Type} prometheus-node-exporter-configuration
22237 Data type representing the configuration of @command{node_exporter}.
22240 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
22241 The prometheus-node-exporter package to use.
22243 @item @code{web-listen-address} (default: @code{":9100"})
22244 Bind the web interface to the specified address.
22246 @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
22247 This directory can be used to export metrics specific to this machine.
22248 Files containing metrics in the text format, with the filename ending in
22249 @code{.prom} should be placed in this directory.
22251 @item @code{extra-options} (default: @code{'()})
22252 Extra options to pass to the Prometheus node exporter.
22257 @subsubheading Zabbix server
22258 @cindex zabbix zabbix-server
22259 Zabbix provides monitoring metrics, among others network utilization, CPU load
22260 and disk space consumption:
22263 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
22264 @item Auto-discovery of servers and network devices and interfaces.
22265 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
22266 @item Distributed monitoring with centralized web administration.
22267 @item Native high performance agents.
22268 @item SLA, and ITIL KPI metrics on reporting.
22269 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
22270 @item Remote command execution through Zabbix proxies.
22273 @c %start of fragment
22275 Available @code{zabbix-server-configuration} fields are:
22277 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
22278 The zabbix-server package.
22282 @deftypevr {@code{zabbix-server-configuration} parameter} string user
22283 User who will run the Zabbix server.
22285 Defaults to @samp{"zabbix"}.
22289 @deftypevr {@code{zabbix-server-configuration} parameter} group group
22290 Group who will run the Zabbix server.
22292 Defaults to @samp{"zabbix"}.
22296 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
22297 Database host name.
22299 Defaults to @samp{"127.0.0.1"}.
22303 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
22306 Defaults to @samp{"zabbix"}.
22310 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
22313 Defaults to @samp{"zabbix"}.
22317 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
22318 Database password. Please, use @code{include-files} with
22319 @code{DBPassword=SECRET} inside a specified file instead.
22321 Defaults to @samp{""}.
22325 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
22328 Defaults to @samp{5432}.
22332 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
22333 Specifies where log messages are written to:
22337 @code{system} - syslog.
22340 @code{file} - file specified with @code{log-file} parameter.
22343 @code{console} - standard output.
22347 Defaults to @samp{""}.
22351 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
22352 Log file name for @code{log-type} @code{file} parameter.
22354 Defaults to @samp{"/var/log/zabbix/server.log"}.
22358 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
22361 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
22365 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
22366 The location of certificate authority (CA) files for SSL server
22367 certificate verification.
22369 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
22373 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
22374 Location of SSL client certificates.
22376 Defaults to @samp{"/etc/ssl/certs"}.
22380 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
22381 Extra options will be appended to Zabbix server configuration file.
22383 Defaults to @samp{""}.
22387 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
22388 You may include individual files or all files in a directory in the
22389 configuration file.
22391 Defaults to @samp{()}.
22395 @c %end of fragment
22397 @subsubheading Zabbix agent
22398 @cindex zabbix zabbix-agent
22400 Zabbix agent gathers information for Zabbix server.
22402 @c %start of fragment
22404 Available @code{zabbix-agent-configuration} fields are:
22406 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
22407 The zabbix-agent package.
22411 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
22412 User who will run the Zabbix agent.
22414 Defaults to @samp{"zabbix"}.
22418 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
22419 Group who will run the Zabbix agent.
22421 Defaults to @samp{"zabbix"}.
22425 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
22426 Unique, case sensitive hostname which is required for active checks and
22427 must match hostname as configured on the server.
22429 Defaults to @samp{""}.
22433 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
22434 Specifies where log messages are written to:
22438 @code{system} - syslog.
22441 @code{file} - file specified with @code{log-file} parameter.
22444 @code{console} - standard output.
22448 Defaults to @samp{""}.
22452 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
22453 Log file name for @code{log-type} @code{file} parameter.
22455 Defaults to @samp{"/var/log/zabbix/agent.log"}.
22459 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
22462 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
22466 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
22467 List of IP addresses, optionally in CIDR notation, or hostnames of
22468 Zabbix servers and Zabbix proxies. Incoming connections will be
22469 accepted only from the hosts listed here.
22471 Defaults to @samp{("127.0.0.1")}.
22475 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
22476 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
22477 proxies for active checks. If port is not specified, default port is
22478 used. If this parameter is not specified, active checks are disabled.
22480 Defaults to @samp{("127.0.0.1")}.
22484 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
22485 Extra options will be appended to Zabbix server configuration file.
22487 Defaults to @samp{""}.
22491 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
22492 You may include individual files or all files in a directory in the
22493 configuration file.
22495 Defaults to @samp{()}.
22499 @c %end of fragment
22501 @subsubheading Zabbix front-end
22502 @cindex zabbix zabbix-front-end
22504 This service provides a WEB interface to Zabbix server.
22506 @c %start of fragment
22508 Available @code{zabbix-front-end-configuration} fields are:
22510 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
22511 NGINX configuration.
22515 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
22516 Database host name.
22518 Defaults to @samp{"localhost"}.
22522 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
22525 Defaults to @samp{5432}.
22529 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
22532 Defaults to @samp{"zabbix"}.
22536 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
22539 Defaults to @samp{"zabbix"}.
22543 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
22544 Database password. Please, use @code{db-secret-file} instead.
22546 Defaults to @samp{""}.
22550 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
22551 Secret file containing the credentials for the Zabbix front-end. The value
22552 must be a local file name, not a G-expression. You are expected to create
22553 this file manually. Its contents will be copied into @file{zabbix.conf.php}
22554 as the value of @code{$DB['PASSWORD']}.
22556 Defaults to @samp{""}.
22560 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
22561 Zabbix server hostname.
22563 Defaults to @samp{"localhost"}.
22567 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
22568 Zabbix server port.
22570 Defaults to @samp{10051}.
22575 @c %end of fragment
22577 @node Kerberos Services
22578 @subsection Kerberos Services
22581 The @code{(gnu services kerberos)} module provides services relating to
22582 the authentication protocol @dfn{Kerberos}.
22584 @subsubheading Krb5 Service
22586 Programs using a Kerberos client library normally
22587 expect a configuration file in @file{/etc/krb5.conf}.
22588 This service generates such a file from a definition provided in the
22589 operating system declaration.
22590 It does not cause any daemon to be started.
22592 No ``keytab'' files are provided by this service---you must explicitly create them.
22593 This service is known to work with the MIT client library, @code{mit-krb5}.
22594 Other implementations have not been tested.
22596 @defvr {Scheme Variable} krb5-service-type
22597 A service type for Kerberos 5 clients.
22601 Here is an example of its use:
22603 (service krb5-service-type
22604 (krb5-configuration
22605 (default-realm "EXAMPLE.COM")
22606 (allow-weak-crypto? #t)
22609 (name "EXAMPLE.COM")
22610 (admin-server "groucho.example.com")
22611 (kdc "karl.example.com"))
22614 (admin-server "kerb-admin.argrx.edu")
22615 (kdc "keys.argrx.edu"))))))
22619 This example provides a Kerberos@tie{}5 client configuration which:
22621 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
22622 of which have distinct administration servers and key distribution centers;
22623 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
22624 specified by clients;
22625 @item Accepts services which only support encryption types known to be weak.
22628 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
22629 Only the most commonly used ones are described here.
22630 For a full list, and more detailed explanation of each, see the MIT
22631 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
22635 @deftp {Data Type} krb5-realm
22636 @cindex realm, kerberos
22639 This field is a string identifying the name of the realm.
22640 A common convention is to use the fully qualified DNS name of your organization,
22641 converted to upper case.
22643 @item @code{admin-server}
22644 This field is a string identifying the host where the administration server is
22648 This field is a string identifying the key distribution center
22653 @deftp {Data Type} krb5-configuration
22656 @item @code{allow-weak-crypto?} (default: @code{#f})
22657 If this flag is @code{#t} then services which only offer encryption algorithms
22658 known to be weak will be accepted.
22660 @item @code{default-realm} (default: @code{#f})
22661 This field should be a string identifying the default Kerberos
22662 realm for the client.
22663 You should set this field to the name of your Kerberos realm.
22664 If this value is @code{#f}
22665 then a realm must be specified with every Kerberos principal when invoking programs
22666 such as @command{kinit}.
22668 @item @code{realms}
22669 This should be a non-empty list of @code{krb5-realm} objects, which clients may
22671 Normally, one of them will have a @code{name} field matching the @code{default-realm}
22677 @subsubheading PAM krb5 Service
22680 The @code{pam-krb5} service allows for login authentication and password
22681 management via Kerberos.
22682 You will need this service if you want PAM enabled applications to authenticate
22683 users using Kerberos.
22685 @defvr {Scheme Variable} pam-krb5-service-type
22686 A service type for the Kerberos 5 PAM module.
22689 @deftp {Data Type} pam-krb5-configuration
22690 Data type representing the configuration of the Kerberos 5 PAM module.
22691 This type has the following parameters:
22693 @item @code{pam-krb5} (default: @code{pam-krb5})
22694 The pam-krb5 package to use.
22696 @item @code{minimum-uid} (default: @code{1000})
22697 The smallest user ID for which Kerberos authentications should be attempted.
22698 Local accounts with lower values will silently fail to authenticate.
22703 @node LDAP Services
22704 @subsection LDAP Services
22706 @cindex nslcd, LDAP service
22708 The @code{(gnu services authentication)} module provides the
22709 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
22710 server. In addition to configuring the service itself, you may want to add
22711 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
22712 Switch} for detailed information.
22714 Here is a simple operating system declaration with a default configuration of
22715 the @code{nslcd-service-type} and a Name Service Switch configuration that
22716 consults the @code{ldap} name service last:
22719 (use-service-modules authentication)
22720 (use-modules (gnu system nss))
22726 (service nslcd-service-type)
22727 (service dhcp-client-service-type)
22729 (name-service-switch
22730 (let ((services (list (name-service (name "db"))
22731 (name-service (name "files"))
22732 (name-service (name "ldap")))))
22733 (name-service-switch
22734 (inherit %mdns-host-lookup-nss)
22735 (password services)
22738 (netgroup services)
22739 (gshadow services)))))
22742 @c %start of generated documentation for nslcd-configuration
22744 Available @code{nslcd-configuration} fields are:
22746 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
22747 The @code{nss-pam-ldapd} package to use.
22751 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
22752 The number of threads to start that can handle requests and perform LDAP
22753 queries. Each thread opens a separate connection to the LDAP server.
22754 The default is to start 5 threads.
22756 Defaults to @samp{disabled}.
22760 @deftypevr {@code{nslcd-configuration} parameter} string uid
22761 This specifies the user id with which the daemon should be run.
22763 Defaults to @samp{"nslcd"}.
22767 @deftypevr {@code{nslcd-configuration} parameter} string gid
22768 This specifies the group id with which the daemon should be run.
22770 Defaults to @samp{"nslcd"}.
22774 @deftypevr {@code{nslcd-configuration} parameter} log-option log
22775 This option controls the way logging is done via a list containing
22776 SCHEME and LEVEL. The SCHEME argument may either be the symbols
22777 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
22778 argument is optional and specifies the log level. The log level may be
22779 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
22780 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
22781 specified log level or higher are logged.
22783 Defaults to @samp{("/var/log/nslcd" info)}.
22787 @deftypevr {@code{nslcd-configuration} parameter} list uri
22788 The list of LDAP server URIs. Normally, only the first server will be
22789 used with the following servers as fall-back.
22791 Defaults to @samp{("ldap://localhost:389/")}.
22795 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
22796 The version of the LDAP protocol to use. The default is to use the
22797 maximum version supported by the LDAP library.
22799 Defaults to @samp{disabled}.
22803 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
22804 Specifies the distinguished name with which to bind to the directory
22805 server for lookups. The default is to bind anonymously.
22807 Defaults to @samp{disabled}.
22811 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
22812 Specifies the credentials with which to bind. This option is only
22813 applicable when used with binddn.
22815 Defaults to @samp{disabled}.
22819 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
22820 Specifies the distinguished name to use when the root user tries to
22821 modify a user's password using the PAM module.
22823 Defaults to @samp{disabled}.
22827 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
22828 Specifies the credentials with which to bind if the root user tries to
22829 change a user's password. This option is only applicable when used with
22832 Defaults to @samp{disabled}.
22836 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
22837 Specifies the SASL mechanism to be used when performing SASL
22840 Defaults to @samp{disabled}.
22844 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
22845 Specifies the SASL realm to be used when performing SASL authentication.
22847 Defaults to @samp{disabled}.
22851 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
22852 Specifies the authentication identity to be used when performing SASL
22855 Defaults to @samp{disabled}.
22859 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
22860 Specifies the authorization identity to be used when performing SASL
22863 Defaults to @samp{disabled}.
22867 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
22868 Determines whether the LDAP server host name should be canonicalised. If
22869 this is enabled the LDAP library will do a reverse host name lookup. By
22870 default, it is left up to the LDAP library whether this check is
22873 Defaults to @samp{disabled}.
22877 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
22878 Set the name for the GSS-API Kerberos credentials cache.
22880 Defaults to @samp{disabled}.
22884 @deftypevr {@code{nslcd-configuration} parameter} string base
22885 The directory search base.
22887 Defaults to @samp{"dc=example,dc=com"}.
22891 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
22892 Specifies the search scope (subtree, onelevel, base or children). The
22893 default scope is subtree; base scope is almost never useful for name
22894 service lookups; children scope is not supported on all servers.
22896 Defaults to @samp{(subtree)}.
22900 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
22901 Specifies the policy for dereferencing aliases. The default policy is
22902 to never dereference aliases.
22904 Defaults to @samp{disabled}.
22908 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
22909 Specifies whether automatic referral chasing should be enabled. The
22910 default behaviour is to chase referrals.
22912 Defaults to @samp{disabled}.
22916 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
22917 This option allows for custom attributes to be looked up instead of the
22918 default RFC 2307 attributes. It is a list of maps, each consisting of
22919 the name of a map, the RFC 2307 attribute to match and the query
22920 expression for the attribute as it is available in the directory.
22922 Defaults to @samp{()}.
22926 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
22927 A list of filters consisting of the name of a map to which the filter
22928 applies and an LDAP search filter expression.
22930 Defaults to @samp{()}.
22934 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
22935 Specifies the time limit in seconds to use when connecting to the
22936 directory server. The default value is 10 seconds.
22938 Defaults to @samp{disabled}.
22942 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
22943 Specifies the time limit (in seconds) to wait for a response from the
22944 LDAP server. A value of zero, which is the default, is to wait
22945 indefinitely for searches to be completed.
22947 Defaults to @samp{disabled}.
22951 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
22952 Specifies the period if inactivity (in seconds) after which the con‐
22953 nection to the LDAP server will be closed. The default is not to time
22956 Defaults to @samp{disabled}.
22960 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
22961 Specifies the number of seconds to sleep when connecting to all LDAP
22962 servers fails. By default one second is waited between the first
22963 failure and the first retry.
22965 Defaults to @samp{disabled}.
22969 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
22970 Specifies the time after which the LDAP server is considered to be
22971 permanently unavailable. Once this time is reached retries will be done
22972 only once per this time period. The default value is 10 seconds.
22974 Defaults to @samp{disabled}.
22978 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
22979 Specifies whether to use SSL/TLS or not (the default is not to). If
22980 'start-tls is specified then StartTLS is used rather than raw LDAP over
22983 Defaults to @samp{disabled}.
22987 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
22988 Specifies what checks to perform on a server-supplied certificate. The
22989 meaning of the values is described in the ldap.conf(5) manual page.
22991 Defaults to @samp{disabled}.
22995 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
22996 Specifies the directory containing X.509 certificates for peer authen‐
22997 tication. This parameter is ignored when using GnuTLS.
22999 Defaults to @samp{disabled}.
23003 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
23004 Specifies the path to the X.509 certificate for peer authentication.
23006 Defaults to @samp{disabled}.
23010 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
23011 Specifies the path to an entropy source. This parameter is ignored when
23014 Defaults to @samp{disabled}.
23018 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
23019 Specifies the ciphers to use for TLS as a string.
23021 Defaults to @samp{disabled}.
23025 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
23026 Specifies the path to the file containing the local certificate for
23027 client TLS authentication.
23029 Defaults to @samp{disabled}.
23033 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
23034 Specifies the path to the file containing the private key for client TLS
23037 Defaults to @samp{disabled}.
23041 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
23042 Set this to a number greater than 0 to request paged results from the
23043 LDAP server in accordance with RFC2696. The default (0) is to not
23044 request paged results.
23046 Defaults to @samp{disabled}.
23050 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
23051 This option prevents group membership lookups through LDAP for the
23052 specified users. Alternatively, the value 'all-local may be used. With
23053 that value nslcd builds a full list of non-LDAP users on startup.
23055 Defaults to @samp{disabled}.
23059 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
23060 This option ensures that LDAP users with a numeric user id lower than
23061 the specified value are ignored.
23063 Defaults to @samp{disabled}.
23067 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
23068 This option specifies an offset that is added to all LDAP numeric user
23069 ids. This can be used to avoid user id collisions with local users.
23071 Defaults to @samp{disabled}.
23075 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
23076 This option specifies an offset that is added to all LDAP numeric group
23077 ids. This can be used to avoid user id collisions with local groups.
23079 Defaults to @samp{disabled}.
23083 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
23084 If this option is set, the member attribute of a group may point to
23085 another group. Members of nested groups are also returned in the higher
23086 level group and parent groups are returned when finding groups for a
23087 specific user. The default is not to perform extra searches for nested
23090 Defaults to @samp{disabled}.
23094 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
23095 If this option is set, the group member list is not retrieved when
23096 looking up groups. Lookups for finding which groups a user belongs to
23097 will remain functional so the user will likely still get the correct
23098 groups assigned on login.
23100 Defaults to @samp{disabled}.
23104 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
23105 If this option is set, functions which cause all user/group entries to
23106 be loaded from the directory will not succeed in doing so. This can
23107 dramatically reduce LDAP server load in situations where there are a
23108 great number of users and/or groups. This option is not recommended for
23109 most configurations.
23111 Defaults to @samp{disabled}.
23115 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
23116 This option can be used to specify how user and group names are verified
23117 within the system. This pattern is used to check all user and group
23118 names that are requested and returned from LDAP.
23120 Defaults to @samp{disabled}.
23124 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
23125 This specifies whether or not to perform searches using case-insensitive
23126 matching. Enabling this could open up the system to authorization
23127 bypass vulnerabilities and introduce nscd cache poisoning
23128 vulnerabilities which allow denial of service.
23130 Defaults to @samp{disabled}.
23134 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
23135 This option specifies whether password policy controls are requested and
23136 handled from the LDAP server when performing user authentication.
23138 Defaults to @samp{disabled}.
23142 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
23143 By default nslcd performs an LDAP search with the user's credentials
23144 after BIND (authentication) to ensure that the BIND operation was
23145 successful. The default search is a simple check to see if the user's
23146 DN exists. A search filter can be specified that will be used instead.
23147 It should return at least one entry.
23149 Defaults to @samp{disabled}.
23153 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
23154 This option allows flexible fine tuning of the authorisation check that
23155 should be performed. The search filter specified is executed and if any
23156 entries match, access is granted, otherwise access is denied.
23158 Defaults to @samp{disabled}.
23162 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
23163 If this option is set password modification using pam_ldap will be
23164 denied and the specified message will be presented to the user instead.
23165 The message can be used to direct the user to an alternative means of
23166 changing their password.
23168 Defaults to @samp{disabled}.
23172 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
23173 List of pam service names for which LDAP authentication should suffice.
23175 Defaults to @samp{()}.
23179 @c %end of generated documentation for nslcd-configuration
23183 @subsection Web Services
23188 The @code{(gnu services web)} module provides the Apache HTTP Server,
23189 the nginx web server, and also a fastcgi wrapper daemon.
23191 @subsubheading Apache HTTP Server
23193 @deffn {Scheme Variable} httpd-service-type
23194 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
23195 (@dfn{httpd}). The value for this service type is a
23196 @code{httpd-configuration} record.
23198 A simple example configuration is given below.
23201 (service httpd-service-type
23202 (httpd-configuration
23205 (server-name "www.example.com")
23206 (document-root "/srv/http/www.example.com")))))
23209 Other services can also extend the @code{httpd-service-type} to add to
23213 (simple-service 'www.example.com-server httpd-service-type
23217 (list (string-join '("ServerName www.example.com"
23218 "DocumentRoot /srv/http/www.example.com")
23223 The details for the @code{httpd-configuration}, @code{httpd-module},
23224 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
23227 @deffn {Data Type} httpd-configuration
23228 This data type represents the configuration for the httpd service.
23231 @item @code{package} (default: @code{httpd})
23232 The httpd package to use.
23234 @item @code{pid-file} (default: @code{"/var/run/httpd"})
23235 The pid file used by the shepherd-service.
23237 @item @code{config} (default: @code{(httpd-config-file)})
23238 The configuration file to use with the httpd service. The default value
23239 is a @code{httpd-config-file} record, but this can also be a different
23240 G-expression that generates a file, for example a @code{plain-file}. A
23241 file outside of the store can also be specified through a string.
23246 @deffn {Data Type} httpd-module
23247 This data type represents a module for the httpd service.
23251 The name of the module.
23254 The file for the module. This can be relative to the httpd package being
23255 used, the absolute location of a file, or a G-expression for a file
23256 within the store, for example @code{(file-append mod-wsgi
23257 "/modules/mod_wsgi.so")}.
23262 @defvr {Scheme Variable} %default-httpd-modules
23263 A default list of @code{httpd-module} objects.
23266 @deffn {Data Type} httpd-config-file
23267 This data type represents a configuration file for the httpd service.
23270 @item @code{modules} (default: @code{%default-httpd-modules})
23271 The modules to load. Additional modules can be added here, or loaded by
23272 additional configuration.
23274 For example, in order to handle requests for PHP files, you can use Apache’s
23275 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
23278 (service httpd-service-type
23279 (httpd-configuration
23284 (name "proxy_module")
23285 (file "modules/mod_proxy.so"))
23287 (name "proxy_fcgi_module")
23288 (file "modules/mod_proxy_fcgi.so"))
23289 %default-httpd-modules))
23290 (extra-config (list "\
23291 <FilesMatch \\.php$>
23292 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
23293 </FilesMatch>"))))))
23294 (service php-fpm-service-type
23295 (php-fpm-configuration
23296 (socket "/var/run/php-fpm.sock")
23297 (socket-group "httpd")))
23300 @item @code{server-root} (default: @code{httpd})
23301 The @code{ServerRoot} in the configuration file, defaults to the httpd
23302 package. Directives including @code{Include} and @code{LoadModule} are
23303 taken as relative to the server root.
23305 @item @code{server-name} (default: @code{#f})
23306 The @code{ServerName} in the configuration file, used to specify the
23307 request scheme, hostname and port that the server uses to identify
23310 This doesn't need to be set in the server config, and can be specified
23311 in virtual hosts. The default is @code{#f} to not specify a
23314 @item @code{document-root} (default: @code{"/srv/http"})
23315 The @code{DocumentRoot} from which files will be served.
23317 @item @code{listen} (default: @code{'("80")})
23318 The list of values for the @code{Listen} directives in the config
23319 file. The value should be a list of strings, when each string can
23320 specify the port number to listen on, and optionally the IP address and
23323 @item @code{pid-file} (default: @code{"/var/run/httpd"})
23324 The @code{PidFile} to use. This should match the @code{pid-file} set in
23325 the @code{httpd-configuration} so that the Shepherd service is
23326 configured correctly.
23328 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
23329 The @code{ErrorLog} to which the server will log errors.
23331 @item @code{user} (default: @code{"httpd"})
23332 The @code{User} which the server will answer requests as.
23334 @item @code{group} (default: @code{"httpd"})
23335 The @code{Group} which the server will answer requests as.
23337 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
23338 A flat list of strings and G-expressions which will be added to the end
23339 of the configuration file.
23341 Any values which the service is extended with will be appended to this
23347 @deffn {Data Type} httpd-virtualhost
23348 This data type represents a virtualhost configuration block for the httpd service.
23350 These should be added to the extra-config for the httpd-service.
23353 (simple-service 'www.example.com-server httpd-service-type
23357 (list (string-join '("ServerName www.example.com"
23358 "DocumentRoot /srv/http/www.example.com")
23363 @item @code{addresses-and-ports}
23364 The addresses and ports for the @code{VirtualHost} directive.
23366 @item @code{contents}
23367 The contents of the @code{VirtualHost} directive, this should be a list
23368 of strings and G-expressions.
23373 @subsubheading NGINX
23375 @deffn {Scheme Variable} nginx-service-type
23376 Service type for the @uref{https://nginx.org/,NGinx} web server. The
23377 value for this service type is a @code{<nginx-configuration>} record.
23379 A simple example configuration is given below.
23382 (service nginx-service-type
23383 (nginx-configuration
23385 (list (nginx-server-configuration
23386 (server-name '("www.example.com"))
23387 (root "/srv/http/www.example.com"))))))
23390 In addition to adding server blocks to the service configuration
23391 directly, this service can be extended by other services to add server
23392 blocks, as in this example:
23395 (simple-service 'my-extra-server nginx-service-type
23396 (list (nginx-server-configuration
23397 (root "/srv/http/extra-website")
23398 (try-files (list "$uri" "$uri/index.html")))))
23402 At startup, @command{nginx} has not yet read its configuration file, so
23403 it uses a default file to log error messages. If it fails to load its
23404 configuration file, that is where error messages are logged. After the
23405 configuration file is loaded, the default error log file changes as per
23406 configuration. In our case, startup error messages can be found in
23407 @file{/var/run/nginx/logs/error.log}, and after configuration in
23408 @file{/var/log/nginx/error.log}. The second location can be changed
23409 with the @var{log-directory} configuration option.
23411 @deffn {Data Type} nginx-configuration
23412 This data type represents the configuration for NGinx. Some
23413 configuration can be done through this and the other provided record
23414 types, or alternatively, a config file can be provided.
23417 @item @code{nginx} (default: @code{nginx})
23418 The nginx package to use.
23420 @item @code{log-directory} (default: @code{"/var/log/nginx"})
23421 The directory to which NGinx will write log files.
23423 @item @code{run-directory} (default: @code{"/var/run/nginx"})
23424 The directory in which NGinx will create a pid file, and write temporary
23427 @item @code{server-blocks} (default: @code{'()})
23428 A list of @dfn{server blocks} to create in the generated configuration
23429 file, the elements should be of type
23430 @code{<nginx-server-configuration>}.
23432 The following example would setup NGinx to serve @code{www.example.com}
23433 from the @code{/srv/http/www.example.com} directory, without using
23436 (service nginx-service-type
23437 (nginx-configuration
23439 (list (nginx-server-configuration
23440 (server-name '("www.example.com"))
23441 (root "/srv/http/www.example.com"))))))
23444 @item @code{upstream-blocks} (default: @code{'()})
23445 A list of @dfn{upstream blocks} to create in the generated configuration
23446 file, the elements should be of type
23447 @code{<nginx-upstream-configuration>}.
23449 Configuring upstreams through the @code{upstream-blocks} can be useful
23450 when combined with @code{locations} in the
23451 @code{<nginx-server-configuration>} records. The following example
23452 creates a server configuration with one location configuration, that
23453 will proxy requests to a upstream configuration, which will handle
23454 requests with two servers.
23459 (nginx-configuration
23461 (list (nginx-server-configuration
23462 (server-name '("www.example.com"))
23463 (root "/srv/http/www.example.com")
23466 (nginx-location-configuration
23468 (body '("proxy_pass http://server-proxy;"))))))))
23470 (list (nginx-upstream-configuration
23471 (name "server-proxy")
23472 (servers (list "server1.example.com"
23473 "server2.example.com")))))))
23476 @item @code{file} (default: @code{#f})
23477 If a configuration @var{file} is provided, this will be used, rather than
23478 generating a configuration file from the provided @code{log-directory},
23479 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
23480 proper operation, these arguments should match what is in @var{file} to ensure
23481 that the directories are created when the service is activated.
23483 This can be useful if you have an existing configuration file, or it's
23484 not possible to do what is required through the other parts of the
23485 nginx-configuration record.
23487 @item @code{server-names-hash-bucket-size} (default: @code{#f})
23488 Bucket size for the server names hash tables, defaults to @code{#f} to
23489 use the size of the processors cache line.
23491 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
23492 Maximum bucket size for the server names hash tables.
23494 @item @code{modules} (default: @code{'()})
23495 List of nginx dynamic modules to load. This should be a list of file
23496 names of loadable modules, as in this example:
23501 (file-append nginx-accept-language-module "\
23502 /etc/nginx/modules/ngx_http_accept_language_module.so")
23503 (file-append nginx-lua-module "\
23504 /etc/nginx/modules/ngx_http_lua_module.so")))
23507 @item @code{lua-package-path} (default: @code{'()})
23508 List of nginx lua packages to load. This should be a list of package
23509 names of loadable lua modules, as in this example:
23512 (lua-package-path (list lua-resty-core
23519 @item @code{lua-package-cpath} (default: @code{'()})
23520 List of nginx lua C packages to load. This should be a list of package
23521 names of loadable lua C modules, as in this example:
23524 (lua-package-cpath (list lua-resty-signal))
23527 @item @code{global-directives} (default: @code{'((events . ()))})
23528 Association list of global directives for the top level of the nginx
23529 configuration. Values may themselves be association lists.
23533 `((worker_processes . 16)
23535 (events . ((worker_connections . 1024)))))
23538 @item @code{extra-content} (default: @code{""})
23539 Extra content for the @code{http} block. Should be string or a string
23540 valued G-expression.
23545 @deftp {Data Type} nginx-server-configuration
23546 Data type representing the configuration of an nginx server block.
23547 This type has the following parameters:
23550 @item @code{listen} (default: @code{'("80" "443 ssl")})
23551 Each @code{listen} directive sets the address and port for IP, or the
23552 path for a UNIX-domain socket on which the server will accept requests.
23553 Both address and port, or only address or only port can be specified.
23554 An address may also be a hostname, for example:
23557 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
23560 @item @code{server-name} (default: @code{(list 'default)})
23561 A list of server names this server represents. @code{'default} represents the
23562 default server for connections matching no other server.
23564 @item @code{root} (default: @code{"/srv/http"})
23565 Root of the website nginx will serve.
23567 @item @code{locations} (default: @code{'()})
23568 A list of @dfn{nginx-location-configuration} or
23569 @dfn{nginx-named-location-configuration} records to use within this
23572 @item @code{index} (default: @code{(list "index.html")})
23573 Index files to look for when clients ask for a directory. If it cannot be found,
23574 Nginx will send the list of files in the directory.
23576 @item @code{try-files} (default: @code{'()})
23577 A list of files whose existence is checked in the specified order.
23578 @code{nginx} will use the first file it finds to process the request.
23580 @item @code{ssl-certificate} (default: @code{#f})
23581 Where to find the certificate for secure connections. Set it to @code{#f} if
23582 you don't have a certificate or you don't want to use HTTPS.
23584 @item @code{ssl-certificate-key} (default: @code{#f})
23585 Where to find the private key for secure connections. Set it to @code{#f} if
23586 you don't have a key or you don't want to use HTTPS.
23588 @item @code{server-tokens?} (default: @code{#f})
23589 Whether the server should add its configuration to response.
23591 @item @code{raw-content} (default: @code{'()})
23592 A list of raw lines added to the server block.
23597 @deftp {Data Type} nginx-upstream-configuration
23598 Data type representing the configuration of an nginx @code{upstream}
23599 block. This type has the following parameters:
23603 Name for this group of servers.
23605 @item @code{servers}
23606 Specify the addresses of the servers in the group. The address can be
23607 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
23608 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
23609 prefix @samp{unix:}. For addresses using an IP address or domain name,
23610 the default port is 80, and a different port can be specified
23616 @deftp {Data Type} nginx-location-configuration
23617 Data type representing the configuration of an nginx @code{location}
23618 block. This type has the following parameters:
23622 URI which this location block matches.
23624 @anchor{nginx-location-configuration body}
23626 Body of the location block, specified as a list of strings. This can contain
23628 configuration directives. For example, to pass requests to a upstream
23629 server group defined using an @code{nginx-upstream-configuration} block,
23630 the following directive would be specified in the body @samp{(list "proxy_pass
23631 http://upstream-name;")}.
23636 @deftp {Data Type} nginx-named-location-configuration
23637 Data type representing the configuration of an nginx named location
23638 block. Named location blocks are used for request redirection, and not
23639 used for regular request processing. This type has the following
23644 Name to identify this location block.
23647 @xref{nginx-location-configuration body}, as the body for named location
23648 blocks can be used in a similar way to the
23649 @code{nginx-location-configuration body}. One restriction is that the
23650 body of a named location block cannot contain location blocks.
23655 @subsubheading Varnish Cache
23657 Varnish is a fast cache server that sits in between web applications
23658 and end users. It proxies requests from clients and caches the
23659 accessed URLs such that multiple requests for the same resource only
23660 creates one request to the back-end.
23662 @defvr {Scheme Variable} varnish-service-type
23663 Service type for the Varnish daemon.
23666 @deftp {Data Type} varnish-configuration
23667 Data type representing the @code{varnish} service configuration.
23668 This type has the following parameters:
23671 @item @code{package} (default: @code{varnish})
23672 The Varnish package to use.
23674 @item @code{name} (default: @code{"default"})
23675 A name for this Varnish instance. Varnish will create a directory in
23676 @file{/var/varnish/} with this name and keep temporary files there. If
23677 the name starts with a forward slash, it is interpreted as an absolute
23680 Pass the @code{-n} argument to other Varnish programs to connect to the
23681 named instance, e.g.@: @command{varnishncsa -n default}.
23683 @item @code{backend} (default: @code{"localhost:8080"})
23684 The backend to use. This option has no effect if @code{vcl} is set.
23686 @item @code{vcl} (default: #f)
23687 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
23688 is @code{#f}, Varnish will proxy @code{backend} using the default
23689 configuration. Otherwise this must be a file-like object with valid
23692 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
23693 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
23694 can do something along these lines:
23697 (define %gnu-mirror
23698 (plain-file "gnu.vcl"
23700 backend gnu @{ .host = \"www.gnu.org\"; @}"))
23704 (services (cons (service varnish-service-type
23705 (varnish-configuration
23707 (vcl %gnu-mirror)))
23711 The configuration of an already running Varnish instance can be inspected
23712 and changed using the @command{varnishadm} program.
23714 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
23715 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
23716 comprehensive documentation on Varnish and its configuration language.
23718 @item @code{listen} (default: @code{'("localhost:80")})
23719 List of addresses Varnish will listen on.
23721 @item @code{storage} (default: @code{'("malloc,128m")})
23722 List of storage backends that will be available in VCL.
23724 @item @code{parameters} (default: @code{'()})
23725 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
23727 @item @code{extra-options} (default: @code{'()})
23728 Additional arguments to pass to the @command{varnishd} process.
23733 @subsubheading Patchwork
23735 Patchwork is a patch tracking system. It can collect patches sent to a
23736 mailing list, and display them in a web interface.
23738 @defvr {Scheme Variable} patchwork-service-type
23739 Service type for Patchwork.
23742 The following example is an example of a minimal service for Patchwork, for
23743 the @code{patchwork.example.com} domain.
23746 (service patchwork-service-type
23747 (patchwork-configuration
23748 (domain "patchwork.example.com")
23750 (patchwork-settings-module
23751 (allowed-hosts (list domain))
23752 (default-from-email "patchwork@@patchwork.example.com")))
23753 (getmail-retriever-config
23754 (getmail-retriever-configuration
23755 (type "SimpleIMAPSSLRetriever")
23756 (server "imap.example.com")
23758 (username "patchwork")
23760 (list (file-append coreutils "/bin/cat")
23761 "/etc/getmail-patchwork-imap-password"))
23763 '((mailboxes . ("Patches"))))))))
23767 There are three records for configuring the Patchwork service. The
23768 @code{<patchwork-configuration>} relates to the configuration for Patchwork
23769 within the HTTPD service.
23771 The @code{settings-module} field within the @code{<patchwork-configuration>}
23772 record can be populated with the @code{<patchwork-settings-module>} record,
23773 which describes a settings module that is generated within the Guix store.
23775 For the @code{database-configuration} field within the
23776 @code{<patchwork-settings-module>}, the
23777 @code{<patchwork-database-configuration>} must be used.
23779 @deftp {Data Type} patchwork-configuration
23780 Data type representing the Patchwork service configuration. This type has the
23781 following parameters:
23784 @item @code{patchwork} (default: @code{patchwork})
23785 The Patchwork package to use.
23787 @item @code{domain}
23788 The domain to use for Patchwork, this is used in the HTTPD service virtual
23791 @item @code{settings-module}
23792 The settings module to use for Patchwork. As a Django application, Patchwork
23793 is configured with a Python module containing the settings. This can either be
23794 an instance of the @code{<patchwork-settings-module>} record, any other record
23795 that represents the settings in the store, or a directory outside of the
23798 @item @code{static-path} (default: @code{"/static/"})
23799 The path under which the HTTPD service should serve the static files.
23801 @item @code{getmail-retriever-config}
23802 The getmail-retriever-configuration record value to use with
23803 Patchwork. Getmail will be configured with this value, the messages will be
23804 delivered to Patchwork.
23809 @deftp {Data Type} patchwork-settings-module
23810 Data type representing a settings module for Patchwork. Some of these
23811 settings relate directly to Patchwork, but others relate to Django, the web
23812 framework used by Patchwork, or the Django Rest Framework library. This type
23813 has the following parameters:
23816 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
23817 The database connection settings used for Patchwork. See the
23818 @code{<patchwork-database-configuration>} record type for more information.
23820 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
23821 Patchwork, as a Django web application uses a secret key for cryptographically
23822 signing values. This file should contain a unique unpredictable value.
23824 If this file does not exist, it will be created and populated with a random
23825 value by the patchwork-setup shepherd service.
23827 This setting relates to Django.
23829 @item @code{allowed-hosts}
23830 A list of valid hosts for this Patchwork service. This should at least include
23831 the domain specified in the @code{<patchwork-configuration>} record.
23833 This is a Django setting.
23835 @item @code{default-from-email}
23836 The email address from which Patchwork should send email by default.
23838 This is a Patchwork setting.
23840 @item @code{static-url} (default: @code{#f})
23841 The URL to use when serving static assets. It can be part of a URL, or a full
23842 URL, but must end in a @code{/}.
23844 If the default value is used, the @code{static-path} value from the
23845 @code{<patchwork-configuration>} record will be used.
23847 This is a Django setting.
23849 @item @code{admins} (default: @code{'()})
23850 Email addresses to send the details of errors that occur. Each value should
23851 be a list containing two elements, the name and then the email address.
23853 This is a Django setting.
23855 @item @code{debug?} (default: @code{#f})
23856 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
23857 messages will be shown.
23859 This is a Django setting.
23861 @item @code{enable-rest-api?} (default: @code{#t})
23862 Whether to enable the Patchwork REST API.
23864 This is a Patchwork setting.
23866 @item @code{enable-xmlrpc?} (default: @code{#t})
23867 Whether to enable the XML RPC API.
23869 This is a Patchwork setting.
23871 @item @code{force-https-links?} (default: @code{#t})
23872 Whether to use HTTPS links on Patchwork pages.
23874 This is a Patchwork setting.
23876 @item @code{extra-settings} (default: @code{""})
23877 Extra code to place at the end of the Patchwork settings module.
23882 @deftp {Data Type} patchwork-database-configuration
23883 Data type representing the database configuration for Patchwork.
23886 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
23887 The database engine to use.
23889 @item @code{name} (default: @code{"patchwork"})
23890 The name of the database to use.
23892 @item @code{user} (default: @code{"httpd"})
23893 The user to connect to the database as.
23895 @item @code{password} (default: @code{""})
23896 The password to use when connecting to the database.
23898 @item @code{host} (default: @code{""})
23899 The host to make the database connection to.
23901 @item @code{port} (default: @code{""})
23902 The port on which to connect to the database.
23907 @subsubheading Mumi
23909 @cindex Mumi, Debbugs Web interface
23910 @cindex Debbugs, Mumi Web interface
23911 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
23912 Web interface to the Debbugs bug tracker, by default for
23913 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
23914 but it also fetches and indexes mail retrieved from Debbugs.
23916 @defvr {Scheme Variable} mumi-service-type
23917 This is the service type for Mumi.
23920 @deftp {Data Type} mumi-configuration
23921 Data type representing the Mumi service configuration. This type has the
23925 @item @code{mumi} (default: @code{mumi})
23926 The Mumi package to use.
23928 @item @code{mailer?} (default: @code{#true})
23929 Whether to enable or disable the mailer component.
23931 @item @code{mumi-configuration-sender}
23932 The email address used as the sender for comments.
23934 @item @code{mumi-configuration-smtp}
23935 A URI to configure the SMTP settings for Mailutils. This could be
23936 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
23937 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
23938 mailutils, GNU@tie{}Mailutils}.
23944 @subsubheading FastCGI
23947 FastCGI is an interface between the front-end and the back-end of a web
23948 service. It is a somewhat legacy facility; new web services should
23949 generally just talk HTTP between the front-end and the back-end.
23950 However there are a number of back-end services such as PHP or the
23951 optimized HTTP Git repository access that use FastCGI, so we have
23952 support for it in Guix.
23954 To use FastCGI, you configure the front-end web server (e.g., nginx) to
23955 dispatch some subset of its requests to the fastcgi backend, which
23956 listens on a local TCP or UNIX socket. There is an intermediary
23957 @code{fcgiwrap} program that sits between the actual backend process and
23958 the web server. The front-end indicates which backend program to run,
23959 passing that information to the @code{fcgiwrap} process.
23961 @defvr {Scheme Variable} fcgiwrap-service-type
23962 A service type for the @code{fcgiwrap} FastCGI proxy.
23965 @deftp {Data Type} fcgiwrap-configuration
23966 Data type representing the configuration of the @code{fcgiwrap} service.
23967 This type has the following parameters:
23969 @item @code{package} (default: @code{fcgiwrap})
23970 The fcgiwrap package to use.
23972 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
23973 The socket on which the @code{fcgiwrap} process should listen, as a
23974 string. Valid @var{socket} values include
23975 @code{unix:@var{/path/to/unix/socket}},
23976 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
23977 @code{tcp6:[@var{ipv6_addr}]:port}.
23979 @item @code{user} (default: @code{fcgiwrap})
23980 @itemx @code{group} (default: @code{fcgiwrap})
23981 The user and group names, as strings, under which to run the
23982 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
23983 the user asks for the specific user or group names @code{fcgiwrap} that
23984 the corresponding user and/or group is present on the system.
23986 It is possible to configure a FastCGI-backed web service to pass HTTP
23987 authentication information from the front-end to the back-end, and to
23988 allow @code{fcgiwrap} to run the back-end process as a corresponding
23989 local user. To enable this capability on the back-end, run
23990 @code{fcgiwrap} as the @code{root} user and group. Note that this
23991 capability also has to be configured on the front-end as well.
23996 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
23997 with some additional features useful for sites of any size.
23999 These features include:
24001 @item Adaptive process spawning
24002 @item Basic statistics (similar to Apache's mod_status)
24003 @item Advanced process management with graceful stop/start
24004 @item Ability to start workers with different uid/gid/chroot/environment
24005 and different php.ini (replaces safe_mode)
24006 @item Stdout & stderr logging
24007 @item Emergency restart in case of accidental opcode cache destruction
24008 @item Accelerated upload support
24009 @item Support for a "slowlog"
24010 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
24011 a special function to finish request & flush all data while continuing to do
24012 something time-consuming (video converting, stats processing, etc.)
24014 ...@: and much more.
24016 @defvr {Scheme Variable} php-fpm-service-type
24017 A Service type for @code{php-fpm}.
24020 @deftp {Data Type} php-fpm-configuration
24021 Data Type for php-fpm service configuration.
24023 @item @code{php} (default: @code{php})
24024 The php package to use.
24025 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
24026 The address on which to accept FastCGI requests. Valid syntaxes are:
24028 @item @code{"ip.add.re.ss:port"}
24029 Listen on a TCP socket to a specific address on a specific port.
24030 @item @code{"port"}
24031 Listen on a TCP socket to all addresses on a specific port.
24032 @item @code{"/path/to/unix/socket"}
24033 Listen on a unix socket.
24036 @item @code{user} (default: @code{php-fpm})
24037 User who will own the php worker processes.
24038 @item @code{group} (default: @code{php-fpm})
24039 Group of the worker processes.
24040 @item @code{socket-user} (default: @code{php-fpm})
24041 User who can speak to the php-fpm socket.
24042 @item @code{socket-group} (default: @code{nginx})
24043 Group that can speak to the php-fpm socket.
24044 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
24045 The process id of the php-fpm process is written to this file
24046 once the service has started.
24047 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
24048 Log for the php-fpm master process.
24049 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
24050 Detailed settings for the php-fpm process manager.
24053 @item @code{<php-fpm-dynamic-process-manager-configuration>}
24054 @item @code{<php-fpm-static-process-manager-configuration>}
24055 @item @code{<php-fpm-on-demand-process-manager-configuration>}
24057 @item @code{display-errors} (default @code{#f})
24058 Determines whether php errors and warning should be sent to clients
24059 and displayed in their browsers.
24060 This is useful for local php development, but a security risk for public sites,
24061 as error messages can reveal passwords and personal data.
24062 @item @code{timezone} (default @code{#f})
24063 Specifies @code{php_admin_value[date.timezone]} parameter.
24064 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
24065 This file will log the @code{stderr} outputs of php worker processes.
24066 Can be set to @code{#f} to disable logging.
24067 @item @code{file} (default @code{#f})
24068 An optional override of the whole configuration.
24069 You can use the @code{mixed-text-file} function or an absolute filepath for it.
24070 @item @code{php-ini-file} (default @code{#f})
24071 An optional override of the default php settings.
24072 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
24073 You can use the @code{mixed-text-file} function or an absolute filepath for it.
24075 For local development it is useful to set a higher timeout and memory
24076 limit for spawned php processes. This be accomplished with the
24077 following operating system configuration snippet:
24079 (define %local-php-ini
24080 (plain-file "php.ini"
24082 max_execution_time = 1800"))
24086 (services (cons (service php-fpm-service-type
24087 (php-fpm-configuration
24088 (php-ini-file %local-php-ini)))
24092 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
24093 directives} for comprehensive documentation on the acceptable
24094 @file{php.ini} directives.
24098 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
24099 Data Type for the @code{dynamic} php-fpm process manager. With the
24100 @code{dynamic} process manager, spare worker processes are kept around
24101 based on it's configured limits.
24103 @item @code{max-children} (default: @code{5})
24104 Maximum of worker processes.
24105 @item @code{start-servers} (default: @code{2})
24106 How many worker processes should be started on start-up.
24107 @item @code{min-spare-servers} (default: @code{1})
24108 How many spare worker processes should be kept around at minimum.
24109 @item @code{max-spare-servers} (default: @code{3})
24110 How many spare worker processes should be kept around at maximum.
24114 @deftp {Data type} php-fpm-static-process-manager-configuration
24115 Data Type for the @code{static} php-fpm process manager. With the
24116 @code{static} process manager, an unchanging number of worker processes
24119 @item @code{max-children} (default: @code{5})
24120 Maximum of worker processes.
24124 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
24125 Data Type for the @code{on-demand} php-fpm process manager. With the
24126 @code{on-demand} process manager, worker processes are only created as
24129 @item @code{max-children} (default: @code{5})
24130 Maximum of worker processes.
24131 @item @code{process-idle-timeout} (default: @code{10})
24132 The time in seconds after which a process with no requests is killed.
24137 @deffn {Scheme Procedure} nginx-php-location @
24138 [#:nginx-package nginx] @
24139 [socket (string-append "/var/run/php" @
24140 (version-major (package-version php)) @
24142 A helper function to quickly add php to an @code{nginx-server-configuration}.
24145 A simple services setup for nginx with php can look like this:
24147 (services (cons* (service dhcp-client-service-type)
24148 (service php-fpm-service-type)
24149 (service nginx-service-type
24150 (nginx-server-configuration
24151 (server-name '("example.com"))
24152 (root "/srv/http/")
24154 (list (nginx-php-location)))
24156 (ssl-certificate #f)
24157 (ssl-certificate-key #f)))
24161 @cindex cat-avatar-generator
24162 The cat avatar generator is a simple service to demonstrate the use of php-fpm
24163 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
24164 the hash of a user's email address.
24166 @deffn {Scheme Procedure} cat-avatar-generator-service @
24167 [#:cache-dir "/var/cache/cat-avatar-generator"] @
24168 [#:package cat-avatar-generator] @
24169 [#:configuration (nginx-server-configuration)]
24170 Returns an nginx-server-configuration that inherits @code{configuration}. It
24171 extends the nginx configuration to add a server block that serves @code{package},
24172 a version of cat-avatar-generator. During execution, cat-avatar-generator will
24173 be able to use @code{cache-dir} as its cache directory.
24176 A simple setup for cat-avatar-generator can look like this:
24178 (services (cons* (cat-avatar-generator-service
24180 (nginx-server-configuration
24181 (server-name '("example.com"))))
24186 @subsubheading Hpcguix-web
24188 @cindex hpcguix-web
24189 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
24190 program is a customizable web interface to browse Guix packages,
24191 initially designed for users of high-performance computing (HPC)
24194 @defvr {Scheme Variable} hpcguix-web-service-type
24195 The service type for @code{hpcguix-web}.
24198 @deftp {Data Type} hpcguix-web-configuration
24199 Data type for the hpcguix-web service configuration.
24203 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
24204 configuration. The main items available in this spec are:
24207 @item @code{title-prefix} (default: @code{"hpcguix | "})
24208 The page title prefix.
24210 @item @code{guix-command} (default: @code{"guix"})
24211 The @command{guix} command.
24213 @item @code{package-filter-proc} (default: @code{(const #t)})
24214 A procedure specifying how to filter packages that are displayed.
24216 @item @code{package-page-extension-proc} (default: @code{(const '())})
24217 Extension package for @code{hpcguix-web}.
24219 @item @code{menu} (default: @code{'()})
24220 Additional entry in page @code{menu}.
24222 @item @code{channels} (default: @code{%default-channels})
24223 List of channels from which the package list is built (@pxref{Channels}).
24225 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
24226 The expiration time, in seconds, after which the package list is rebuilt from
24227 the latest instances of the given channels.
24230 See the hpcguix-web repository for a
24231 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
24234 @item @code{package} (default: @code{hpcguix-web})
24235 The hpcguix-web package to use.
24239 A typical hpcguix-web service declaration looks like this:
24242 (service hpcguix-web-service-type
24243 (hpcguix-web-configuration
24245 #~(define site-config
24246 (hpcweb-configuration
24247 (title-prefix "Guix-HPC - ")
24248 (menu '(("/about" "ABOUT"))))))))
24252 The hpcguix-web service periodically updates the package list it publishes by
24253 pulling channels from Git. To that end, it needs to access X.509 certificates
24254 so that it can authenticate Git servers when communicating over HTTPS, and it
24255 assumes that @file{/etc/ssl/certs} contains those certificates.
24257 Thus, make sure to add @code{nss-certs} or another certificate package to the
24258 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
24259 more information on X.509 certificates.
24262 @subsubheading gmnisrv
24265 The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
24266 simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
24268 @deffn {Scheme Variable} gmnisrv-service-type
24269 This is the type of the gmnisrv service, whose value should be a
24270 @code{gmnisrv-configuration} object, as in this example:
24273 (service gmnisrv-service-type
24274 (gmnisrv-configuration
24275 (config-file (local-file "./my-gmnisrv.ini"))))
24279 @deftp {Data Type} gmnisrv-configuration
24280 Data type representing the configuration of gmnisrv.
24283 @item @code{package} (default: @var{gmnisrv})
24284 Package object of the gmnisrv server.
24286 @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
24287 File-like object of the gmnisrv configuration file to use. The default
24288 configuration listens on port 1965 and serves files from
24289 @file{/srv/gemini}. Certificates are stored in
24290 @file{/var/lib/gemini/certs}. For more information, run @command{man
24291 gmnisrv} and @command{man gmnisrv.ini}.
24296 @node Certificate Services
24297 @subsection Certificate Services
24300 @cindex HTTP, HTTPS
24301 @cindex Let's Encrypt
24302 @cindex TLS certificates
24303 The @code{(gnu services certbot)} module provides a service to
24304 automatically obtain a valid TLS certificate from the Let's Encrypt
24305 certificate authority. These certificates can then be used to serve
24306 content securely over HTTPS or other TLS-based protocols, with the
24307 knowledge that the client will be able to verify the server's
24310 @url{https://letsencrypt.org/, Let's Encrypt} provides the
24311 @code{certbot} tool to automate the certification process. This tool
24312 first securely generates a key on the server. It then makes a request
24313 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
24314 checks that the request originates from the host in question by using a
24315 challenge-response protocol, requiring the server to provide its
24316 response over HTTP. If that protocol completes successfully, the CA
24317 signs the key, resulting in a certificate. That certificate is valid
24318 for a limited period of time, and therefore to continue to provide TLS
24319 services, the server needs to periodically ask the CA to renew its
24322 The certbot service automates this process: the initial key
24323 generation, the initial certification request to the Let's Encrypt
24324 service, the web server challenge/response integration, writing the
24325 certificate to disk, the automated periodic renewals, and the deployment
24326 tasks associated with the renewal (e.g.@: reloading services, copying keys
24327 with different permissions).
24329 Certbot is run twice a day, at a random minute within the hour. It
24330 won't do anything until your certificates are due for renewal or
24331 revoked, but running it regularly would give your service a chance of
24332 staying online in case a Let's Encrypt-initiated revocation happened for
24335 By using this service, you agree to the ACME Subscriber Agreement, which
24336 can be found there:
24337 @url{https://acme-v01.api.letsencrypt.org/directory}.
24339 @defvr {Scheme Variable} certbot-service-type
24340 A service type for the @code{certbot} Let's Encrypt client. Its value
24341 must be a @code{certbot-configuration} record as in this example:
24344 (define %nginx-deploy-hook
24346 "nginx-deploy-hook"
24347 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
24348 (kill pid SIGHUP))))
24350 (service certbot-service-type
24351 (certbot-configuration
24352 (email "foo@@example.net")
24355 (certificate-configuration
24356 (domains '("example.net" "www.example.net"))
24357 (deploy-hook %nginx-deploy-hook))
24358 (certificate-configuration
24359 (domains '("bar.example.net")))))))
24362 See below for details about @code{certbot-configuration}.
24365 @deftp {Data Type} certbot-configuration
24366 Data type representing the configuration of the @code{certbot} service.
24367 This type has the following parameters:
24370 @item @code{package} (default: @code{certbot})
24371 The certbot package to use.
24373 @item @code{webroot} (default: @code{/var/www})
24374 The directory from which to serve the Let's Encrypt challenge/response
24377 @item @code{certificates} (default: @code{()})
24378 A list of @code{certificates-configuration}s for which to generate
24379 certificates and request signatures. Each certificate has a @code{name}
24380 and several @code{domains}.
24382 @item @code{email} (default: @code{#f})
24383 Optional email address used for registration and recovery contact.
24384 Setting this is encouraged as it allows you to receive important
24385 notifications about the account and issued certificates.
24387 @item @code{server} (default: @code{#f})
24388 Optional URL of ACME server. Setting this overrides certbot's default,
24389 which is the Let's Encrypt server.
24391 @item @code{rsa-key-size} (default: @code{2048})
24392 Size of the RSA key.
24394 @item @code{default-location} (default: @i{see below})
24395 The default @code{nginx-location-configuration}. Because @code{certbot}
24396 needs to be able to serve challenges and responses, it needs to be able
24397 to run a web server. It does so by extending the @code{nginx} web
24398 service with an @code{nginx-server-configuration} listening on the
24399 @var{domains} on port 80, and which has a
24400 @code{nginx-location-configuration} for the @code{/.well-known/} URI
24401 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
24402 these nginx configuration data types.
24404 Requests to other URL paths will be matched by the
24405 @code{default-location}, which if present is added to all
24406 @code{nginx-server-configuration}s.
24408 By default, the @code{default-location} will issue a redirect from
24409 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
24410 you to define what to serve on your site via @code{https}.
24412 Pass @code{#f} to not issue a default location.
24416 @deftp {Data Type} certificate-configuration
24417 Data type representing the configuration of a certificate.
24418 This type has the following parameters:
24421 @item @code{name} (default: @i{see below})
24422 This name is used by Certbot for housekeeping and in file paths; it
24423 doesn't affect the content of the certificate itself. To see
24424 certificate names, run @code{certbot certificates}.
24426 Its default is the first provided domain.
24428 @item @code{domains} (default: @code{()})
24429 The first domain provided will be the subject CN of the certificate, and
24430 all domains will be Subject Alternative Names on the certificate.
24432 @item @code{challenge} (default: @code{#f})
24433 The challenge type that has to be run by certbot. If @code{#f} is specified,
24434 default to the HTTP challenge. If a value is specified, defaults to the
24435 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
24436 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
24437 and gives Let's Encrypt permission to log the public IP address of the
24438 requesting machine.
24440 @item @code{authentication-hook} (default: @code{#f})
24441 Command to be run in a shell once for each certificate challenge to be
24442 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
24443 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
24444 contains the validation string and @code{$CERTBOT_TOKEN} contains the
24445 file name of the resource requested when performing an HTTP-01 challenge.
24447 @item @code{cleanup-hook} (default: @code{#f})
24448 Command to be run in a shell once for each certificate challenge that
24449 have been answered by the @code{auth-hook}. For this command, the shell
24450 variables available in the @code{auth-hook} script are still available, and
24451 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
24452 of the @code{auth-hook} script.
24454 @item @code{deploy-hook} (default: @code{#f})
24455 Command to be run in a shell once for each successfully issued
24456 certificate. For this command, the shell variable
24457 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
24458 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
24459 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
24460 contain a space-delimited list of renewed certificate domains (for
24461 example, @samp{"example.com www.example.com"}.
24466 For each @code{certificate-configuration}, the certificate is saved to
24467 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
24468 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
24470 @subsection DNS Services
24471 @cindex DNS (domain name system)
24472 @cindex domain name system (DNS)
24474 The @code{(gnu services dns)} module provides services related to the
24475 @dfn{domain name system} (DNS). It provides a server service for hosting
24476 an @emph{authoritative} DNS server for multiple zones, slave or master.
24477 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
24478 caching and forwarding DNS server for the LAN, which uses
24479 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
24481 @subsubheading Knot Service
24483 An example configuration of an authoritative server for two zones, one master
24487 (define-zone-entries example.org.zone
24488 ;; Name TTL Class Type Data
24489 ("@@" "" "IN" "A" "127.0.0.1")
24490 ("@@" "" "IN" "NS" "ns")
24491 ("ns" "" "IN" "A" "127.0.0.1"))
24493 (define master-zone
24494 (knot-zone-configuration
24495 (domain "example.org")
24497 (origin "example.org")
24498 (entries example.org.zone)))))
24501 (knot-zone-configuration
24502 (domain "plop.org")
24503 (dnssec-policy "default")
24504 (master (list "plop-master"))))
24506 (define plop-master
24507 (knot-remote-configuration
24509 (address (list "208.76.58.171"))))
24513 (services (cons* (service knot-service-type
24514 (knot-configuration
24515 (remotes (list plop-master))
24516 (zones (list master-zone slave-zone))))
24521 @deffn {Scheme Variable} knot-service-type
24522 This is the type for the Knot DNS server.
24524 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
24525 zones, that is to say domain names you would buy from a registrar. This server
24526 is not a resolver, meaning that it can only resolve names for which it is
24527 authoritative. This server can be configured to serve zones as a master server
24528 or a slave server as a per-zone basis. Slave zones will get their data from
24529 masters, and will serve it as an authoritative server. From the point of view
24530 of a resolver, there is no difference between master and slave.
24532 The following data types are used to configure the Knot DNS server:
24535 @deftp {Data Type} knot-key-configuration
24536 Data type representing a key.
24537 This type has the following parameters:
24540 @item @code{id} (default: @code{""})
24541 An identifier for other configuration fields to refer to this key. IDs must
24542 be unique and must not be empty.
24544 @item @code{algorithm} (default: @code{#f})
24545 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
24546 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
24547 and @code{'hmac-sha512}.
24549 @item @code{secret} (default: @code{""})
24550 The secret key itself.
24555 @deftp {Data Type} knot-acl-configuration
24556 Data type representing an Access Control List (ACL) configuration.
24557 This type has the following parameters:
24560 @item @code{id} (default: @code{""})
24561 An identifier for other configuration fields to refer to this key. IDs must be
24562 unique and must not be empty.
24564 @item @code{address} (default: @code{'()})
24565 An ordered list of IP addresses, network subnets, or network ranges represented
24566 with strings. The query must match one of them. Empty value means that
24567 address match is not required.
24569 @item @code{key} (default: @code{'()})
24570 An ordered list of references to keys represented with strings. The string
24571 must match a key ID defined in a @code{knot-key-configuration}. No key means
24572 that a key is not require to match that ACL.
24574 @item @code{action} (default: @code{'()})
24575 An ordered list of actions that are permitted or forbidden by this ACL. Possible
24576 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
24577 and @code{'update}.
24579 @item @code{deny?} (default: @code{#f})
24580 When true, the ACL defines restrictions. Listed actions are forbidden. When
24581 false, listed actions are allowed.
24586 @deftp {Data Type} zone-entry
24587 Data type representing a record entry in a zone file.
24588 This type has the following parameters:
24591 @item @code{name} (default: @code{"@@"})
24592 The name of the record. @code{"@@"} refers to the origin of the zone. Names
24593 are relative to the origin of the zone. For example, in the @code{example.org}
24594 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
24595 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
24596 refers to @code{ns.example.org}.
24598 @item @code{ttl} (default: @code{""})
24599 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
24601 @item @code{class} (default: @code{"IN"})
24602 The class of the record. Knot currently supports only @code{"IN"} and
24603 partially @code{"CH"}.
24605 @item @code{type} (default: @code{"A"})
24606 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
24607 address), NS (Name Server) and MX (Mail eXchange). Many other types are
24610 @item @code{data} (default: @code{""})
24611 The data contained in the record. For instance an IP address associated with
24612 an A record, or a domain name associated with an NS record. Remember that
24613 domain names are relative to the origin unless they end with a dot.
24618 @deftp {Data Type} zone-file
24619 Data type representing the content of a zone file.
24620 This type has the following parameters:
24623 @item @code{entries} (default: @code{'()})
24624 The list of entries. The SOA record is taken care of, so you don't need to
24625 put it in the list of entries. This list should probably contain an entry
24626 for your primary authoritative DNS server. Other than using a list of entries
24627 directly, you can use @code{define-zone-entries} to define a object containing
24628 the list of entries more easily, that you can later pass to the @code{entries}
24629 field of the @code{zone-file}.
24631 @item @code{origin} (default: @code{""})
24632 The name of your zone. This parameter cannot be empty.
24634 @item @code{ns} (default: @code{"ns"})
24635 The domain of your primary authoritative DNS server. The name is relative to
24636 the origin, unless it ends with a dot. It is mandatory that this primary
24637 DNS server corresponds to an NS record in the zone and that it is associated
24638 to an IP address in the list of entries.
24640 @item @code{mail} (default: @code{"hostmaster"})
24641 An email address people can contact you at, as the owner of the zone. This
24642 is translated as @code{<mail>@@<origin>}.
24644 @item @code{serial} (default: @code{1})
24645 The serial number of the zone. As this is used to keep track of changes by
24646 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
24647 Always increment it when you make a change in your zone.
24649 @item @code{refresh} (default: @code{(* 2 24 3600)})
24650 The frequency at which slaves will do a zone transfer. This value is a number
24651 of seconds. It can be computed by multiplications or with
24652 @code{(string->duration)}.
24654 @item @code{retry} (default: @code{(* 15 60)})
24655 The period after which a slave will retry to contact its master when it fails
24656 to do so a first time.
24658 @item @code{expiry} (default: @code{(* 14 24 3600)})
24659 Default TTL of records. Existing records are considered correct for at most
24660 this amount of time. After this period, resolvers will invalidate their cache
24661 and check again that it still exists.
24663 @item @code{nx} (default: @code{3600})
24664 Default TTL of inexistant records. This delay is usually short because you want
24665 your new domains to reach everyone quickly.
24670 @deftp {Data Type} knot-remote-configuration
24671 Data type representing a remote configuration.
24672 This type has the following parameters:
24675 @item @code{id} (default: @code{""})
24676 An identifier for other configuration fields to refer to this remote. IDs must
24677 be unique and must not be empty.
24679 @item @code{address} (default: @code{'()})
24680 An ordered list of destination IP addresses. Addresses are tried in sequence.
24681 An optional port can be given with the @@ separator. For instance:
24682 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
24684 @item @code{via} (default: @code{'()})
24685 An ordered list of source IP addresses. An empty list will have Knot choose
24686 an appropriate source IP. An optional port can be given with the @@ separator.
24687 The default is to choose at random.
24689 @item @code{key} (default: @code{#f})
24690 A reference to a key, that is a string containing the identifier of a key
24691 defined in a @code{knot-key-configuration} field.
24696 @deftp {Data Type} knot-keystore-configuration
24697 Data type representing a keystore to hold dnssec keys.
24698 This type has the following parameters:
24701 @item @code{id} (default: @code{""})
24702 The id of the keystore. It must not be empty.
24704 @item @code{backend} (default: @code{'pem})
24705 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
24707 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
24708 The configuration string of the backend. An example for the PKCS#11 is:
24709 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
24710 For the pem backend, the string represents a path in the file system.
24715 @deftp {Data Type} knot-policy-configuration
24716 Data type representing a dnssec policy. Knot DNS is able to automatically
24717 sign your zones. It can either generate and manage your keys automatically or
24718 use keys that you generate.
24720 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
24721 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
24722 zone. In order to be trusted, the KSK needs to be present in the parent zone
24723 (usually a top-level domain). If your registrar supports dnssec, you will
24724 have to send them your KSK's hash so they can add a DS record in their zone.
24725 This is not automated and need to be done each time you change your KSK.
24727 The policy also defines the lifetime of keys. Usually, ZSK can be changed
24728 easily and use weaker cryptographic functions (they use lower parameters) in
24729 order to sign records quickly, so they are changed often. The KSK however
24730 requires manual interaction with the registrar, so they are changed less often
24731 and use stronger parameters because they sign only one record.
24733 This type has the following parameters:
24736 @item @code{id} (default: @code{""})
24737 The id of the policy. It must not be empty.
24739 @item @code{keystore} (default: @code{"default"})
24740 A reference to a keystore, that is a string containing the identifier of a
24741 keystore defined in a @code{knot-keystore-configuration} field. The
24742 @code{"default"} identifier means the default keystore (a kasp database that
24743 was setup by this service).
24745 @item @code{manual?} (default: @code{#f})
24746 Whether the key management is manual or automatic.
24748 @item @code{single-type-signing?} (default: @code{#f})
24749 When @code{#t}, use the Single-Type Signing Scheme.
24751 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
24752 An algorithm of signing keys and issued signatures.
24754 @item @code{ksk-size} (default: @code{256})
24755 The length of the KSK. Note that this value is correct for the default
24756 algorithm, but would be unsecure for other algorithms.
24758 @item @code{zsk-size} (default: @code{256})
24759 The length of the ZSK. Note that this value is correct for the default
24760 algorithm, but would be unsecure for other algorithms.
24762 @item @code{dnskey-ttl} (default: @code{'default})
24763 The TTL value for DNSKEY records added into zone apex. The special
24764 @code{'default} value means same as the zone SOA TTL.
24766 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
24767 The period between ZSK publication and the next rollover initiation.
24769 @item @code{propagation-delay} (default: @code{(* 24 3600)})
24770 An extra delay added for each key rollover step. This value should be high
24771 enough to cover propagation of data from the master server to all slaves.
24773 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
24774 A validity period of newly issued signatures.
24776 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
24777 A period how long before a signature expiration the signature will be refreshed.
24779 @item @code{nsec3?} (default: @code{#f})
24780 When @code{#t}, NSEC3 will be used instead of NSEC.
24782 @item @code{nsec3-iterations} (default: @code{5})
24783 The number of additional times the hashing is performed.
24785 @item @code{nsec3-salt-length} (default: @code{8})
24786 The length of a salt field in octets, which is appended to the original owner
24787 name before hashing.
24789 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
24790 The validity period of newly issued salt field.
24795 @deftp {Data Type} knot-zone-configuration
24796 Data type representing a zone served by Knot.
24797 This type has the following parameters:
24800 @item @code{domain} (default: @code{""})
24801 The domain served by this configuration. It must not be empty.
24803 @item @code{file} (default: @code{""})
24804 The file where this zone is saved. This parameter is ignored by master zones.
24805 Empty means default location that depends on the domain name.
24807 @item @code{zone} (default: @code{(zone-file)})
24808 The content of the zone file. This parameter is ignored by slave zones. It
24809 must contain a zone-file record.
24811 @item @code{master} (default: @code{'()})
24812 A list of master remotes. When empty, this zone is a master. When set, this
24813 zone is a slave. This is a list of remotes identifiers.
24815 @item @code{ddns-master} (default: @code{#f})
24816 The main master. When empty, it defaults to the first master in the list of
24819 @item @code{notify} (default: @code{'()})
24820 A list of slave remote identifiers.
24822 @item @code{acl} (default: @code{'()})
24823 A list of acl identifiers.
24825 @item @code{semantic-checks?} (default: @code{#f})
24826 When set, this adds more semantic checks to the zone.
24828 @item @code{disable-any?} (default: @code{#f})
24829 When set, this forbids queries of the ANY type.
24831 @item @code{zonefile-sync} (default: @code{0})
24832 The delay between a modification in memory and on disk. 0 means immediate
24835 @item @code{zonefile-load} (default: @code{#f})
24836 The way the zone file contents are applied during zone load. Possible values
24840 @item @code{#f} for using the default value from Knot,
24841 @item @code{'none} for not using the zone file at all,
24842 @item @code{'difference} for computing the difference between already available
24843 contents and zone contents and applying it to the current zone contents,
24844 @item @code{'difference-no-serial} for the same as @code{'difference}, but
24845 ignoring the SOA serial in the zone file, while the server takes care of it
24847 @item @code{'whole} for loading zone contents from the zone file.
24850 @item @code{journal-content} (default: @code{#f})
24851 The way the journal is used to store zone and its changes. Possible values
24852 are @code{'none} to not use it at all, @code{'changes} to store changes and
24853 @code{'all} to store contents. @code{#f} does not set this option, so the
24854 default value from Knot is used.
24856 @item @code{max-journal-usage} (default: @code{#f})
24857 The maximum size for the journal on disk. @code{#f} does not set this option,
24858 so the default value from Knot is used.
24860 @item @code{max-journal-depth} (default: @code{#f})
24861 The maximum size of the history. @code{#f} does not set this option, so the
24862 default value from Knot is used.
24864 @item @code{max-zone-size} (default: @code{#f})
24865 The maximum size of the zone file. This limit is enforced for incoming
24866 transfer and updates. @code{#f} does not set this option, so the default
24867 value from Knot is used.
24869 @item @code{dnssec-policy} (default: @code{#f})
24870 A reference to a @code{knot-policy-configuration} record, or the special
24871 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
24874 @item @code{serial-policy} (default: @code{'increment})
24875 A policy between @code{'increment} and @code{'unixtime}.
24880 @deftp {Data Type} knot-configuration
24881 Data type representing the Knot configuration.
24882 This type has the following parameters:
24885 @item @code{knot} (default: @code{knot})
24888 @item @code{run-directory} (default: @code{"/var/run/knot"})
24889 The run directory. This directory will be used for pid file and sockets.
24891 @item @code{includes} (default: @code{'()})
24892 A list of strings or file-like objects denoting other files that must be
24893 included at the top of the configuration file.
24895 @cindex secrets, Knot service
24896 This can be used to manage secrets out-of-band. For example, secret
24897 keys may be stored in an out-of-band file not managed by Guix, and
24898 thus not visible in @file{/gnu/store}---e.g., you could store secret
24899 key configuration in @file{/etc/knot/secrets.conf} and add this file
24900 to the @code{includes} list.
24902 One can generate a secret tsig key (for nsupdate and zone transfers with the
24903 keymgr command from the knot package. Note that the package is not automatically
24904 installed by the service. The following example shows how to generate a new
24908 keymgr -t mysecret > /etc/knot/secrets.conf
24909 chmod 600 /etc/knot/secrets.conf
24912 Also note that the generated key will be named @var{mysecret}, so it is the
24913 name that needs to be used in the @var{key} field of the
24914 @code{knot-acl-configuration} record and in other places that need to refer
24917 It can also be used to add configuration not supported by this interface.
24919 @item @code{listen-v4} (default: @code{"0.0.0.0"})
24920 An ip address on which to listen.
24922 @item @code{listen-v6} (default: @code{"::"})
24923 An ip address on which to listen.
24925 @item @code{listen-port} (default: @code{53})
24926 A port on which to listen.
24928 @item @code{keys} (default: @code{'()})
24929 The list of knot-key-configuration used by this configuration.
24931 @item @code{acls} (default: @code{'()})
24932 The list of knot-acl-configuration used by this configuration.
24934 @item @code{remotes} (default: @code{'()})
24935 The list of knot-remote-configuration used by this configuration.
24937 @item @code{zones} (default: @code{'()})
24938 The list of knot-zone-configuration used by this configuration.
24943 @subsubheading Knot Resolver Service
24945 @deffn {Scheme Variable} knot-resolver-service-type
24946 This is the type of the knot resolver service, whose value should be
24947 an @code{knot-resolver-configuration} object as in this example:
24950 (service knot-resolver-service-type
24951 (knot-resolver-configuration
24952 (kresd-config-file (plain-file "kresd.conf" "
24953 net.listen('192.168.0.1', 5353)
24954 user('knot-resolver', 'knot-resolver')
24955 modules = @{ 'hints > iterate', 'stats', 'predict' @}
24956 cache.size = 100 * MB
24960 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
24963 @deftp {Data Type} knot-resolver-configuration
24964 Data type representing the configuration of knot-resolver.
24967 @item @code{package} (default: @var{knot-resolver})
24968 Package object of the knot DNS resolver.
24970 @item @code{kresd-config-file} (default: %kresd.conf)
24971 File-like object of the kresd configuration file to use, by default it
24972 will listen on @code{127.0.0.1} and @code{::1}.
24974 @item @code{garbage-collection-interval} (default: 1000)
24975 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
24981 @subsubheading Dnsmasq Service
24983 @deffn {Scheme Variable} dnsmasq-service-type
24984 This is the type of the dnsmasq service, whose value should be an
24985 @code{dnsmasq-configuration} object as in this example:
24988 (service dnsmasq-service-type
24989 (dnsmasq-configuration
24991 (servers '("192.168.1.1"))))
24995 @deftp {Data Type} dnsmasq-configuration
24996 Data type representing the configuration of dnsmasq.
24999 @item @code{package} (default: @var{dnsmasq})
25000 Package object of the dnsmasq server.
25002 @item @code{no-hosts?} (default: @code{#f})
25003 When true, don't read the hostnames in /etc/hosts.
25005 @item @code{port} (default: @code{53})
25006 The port to listen on. Setting this to zero completely disables DNS
25007 responses, leaving only DHCP and/or TFTP functions.
25009 @item @code{local-service?} (default: @code{#t})
25010 Accept DNS queries only from hosts whose address is on a local subnet,
25011 ie a subnet for which an interface exists on the server.
25013 @item @code{listen-addresses} (default: @code{'()})
25014 Listen on the given IP addresses.
25016 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
25017 The file to read the IP address of the upstream nameservers from.
25019 @item @code{no-resolv?} (default: @code{#f})
25020 When true, don't read @var{resolv-file}.
25022 @item @code{servers} (default: @code{'()})
25023 Specify IP address of upstream servers directly.
25025 @item @code{addresses} (default: @code{'()})
25026 For each entry, specify an IP address to return for any host in the
25027 given domains. Queries in the domains are never forwarded and always
25028 replied to with the specified IP address.
25030 This is useful for redirecting hosts locally, for example:
25033 (service dnsmasq-service-type
25034 (dnsmasq-configuration
25036 '(; Redirect to a local web-server.
25037 "/example.org/127.0.0.1"
25038 ; Redirect subdomain to a specific IP.
25039 "/subdomain.example.org/192.168.1.42"))))
25042 Note that rules in @file{/etc/hosts} take precedence over this.
25044 @item @code{cache-size} (default: @code{150})
25045 Set the size of dnsmasq's cache. Setting the cache size to zero
25048 @item @code{negative-cache?} (default: @code{#t})
25049 When false, disable negative caching.
25051 @item @code{tftp-enable?} (default: @code{#f})
25052 Whether to enable the built-in TFTP server.
25054 @item @code{tftp-no-fail?} (default: @code{#f})
25055 If true, does not fail dnsmasq if the TFTP server could not start up.
25057 @item @code{tftp-single-port?} (default: @code{#f})
25058 Whether to use only one single port for TFTP.
25060 @item @code{tftp-secure?} (default: @code{#f})
25061 If true, only files owned by the user running the dnsmasq process are accessible.
25063 If dnsmasq is being run as root, different rules apply:
25064 @code{tftp-secure?} has no effect, but only files which have the
25065 world-readable bit set are accessible.
25067 @item @code{tftp-max} (default: @code{#f})
25068 If set, sets the maximal number of concurrent connections allowed.
25070 @item @code{tftp-mtu} (default: @code{#f})
25071 If set, sets the MTU for TFTP packets to that value.
25073 @item @code{tftp-no-blocksize?} (default: @code{#f})
25074 If true, stops the TFTP server from negotiating the blocksize with a client.
25076 @item @code{tftp-lowercase?} (default: @code{#f})
25077 Whether to convert all filenames in TFTP requests to lowercase.
25079 @item @code{tftp-port-range} (default: @code{#f})
25080 If set, fixes the dynamical ports (one per client) to the given range
25081 (@code{"<start>,<end>"}).
25083 @item @code{tftp-root} (default: @code{/var/empty,lo})
25084 Look for files to transfer using TFTP relative to the given directory.
25085 When this is set, TFTP paths which include @samp{..} are rejected, to stop clients
25086 getting outside the specified root. Absolute paths (starting with @samp{/}) are
25087 allowed, but they must be within the TFTP-root. If the optional interface
25088 argument is given, the directory is only used for TFTP requests via that
25091 @item @code{tftp-unique-root} (default: @code{#f})
25092 If set, add the IP or hardware address of the TFTP client as a path component
25093 on the end of the TFTP-root. Only valid if a TFTP root is set and the
25094 directory exists. Defaults to adding IP address (in standard dotted-quad
25097 For instance, if @option{--tftp-root} is @samp{/tftp} and client
25098 @samp{1.2.3.4} requests file @file{myfile} then the effective path will
25099 be @file{/tftp/1.2.3.4/myfile} if @file{/tftp/1.2.3.4} exists or
25100 @file{/tftp/myfile} otherwise. When @samp{=mac} is specified it will
25101 append the MAC address instead, using lowercase zero padded digits
25102 separated by dashes, e.g.: @samp{01-02-03-04-aa-bb}. Note that
25103 resolving MAC addresses is only possible if the client is in the local
25104 network or obtained a DHCP lease from dnsmasq.
25109 @subsubheading ddclient Service
25112 The ddclient service described below runs the ddclient daemon, which takes
25113 care of automatically updating DNS entries for service providers such as
25114 @uref{https://dyn.com/dns/, Dyn}.
25116 The following example show instantiates the service with its default
25120 (service ddclient-service-type)
25123 Note that ddclient needs to access credentials that are stored in a
25124 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
25125 @code{secret-file} below). You are expected to create this file manually, in
25126 an ``out-of-band'' fashion (you @emph{could} make this file part of the
25127 service configuration, for instance by using @code{plain-file}, but it will be
25128 world-readable @i{via} @file{/gnu/store}). See the examples in the
25129 @file{share/ddclient} directory of the @code{ddclient} package.
25131 @c %start of fragment
25133 Available @code{ddclient-configuration} fields are:
25135 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
25136 The ddclient package.
25140 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
25141 The period after which ddclient will retry to check IP and domain name.
25143 Defaults to @samp{300}.
25147 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
25148 Use syslog for the output.
25150 Defaults to @samp{#t}.
25154 @deftypevr {@code{ddclient-configuration} parameter} string mail
25157 Defaults to @samp{"root"}.
25161 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
25162 Mail failed update to user.
25164 Defaults to @samp{"root"}.
25168 @deftypevr {@code{ddclient-configuration} parameter} string pid
25169 The ddclient PID file.
25171 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
25175 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
25176 Enable SSL support.
25178 Defaults to @samp{#t}.
25182 @deftypevr {@code{ddclient-configuration} parameter} string user
25183 Specifies the user name or ID that is used when running ddclient
25186 Defaults to @samp{"ddclient"}.
25190 @deftypevr {@code{ddclient-configuration} parameter} string group
25191 Group of the user who will run the ddclient program.
25193 Defaults to @samp{"ddclient"}.
25197 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
25198 Secret file which will be appended to @file{ddclient.conf} file. This
25199 file contains credentials for use by ddclient. You are expected to
25200 create it manually.
25202 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
25206 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
25207 Extra options will be appended to @file{ddclient.conf} file.
25209 Defaults to @samp{()}.
25214 @c %end of fragment
25218 @subsection VPN Services
25219 @cindex VPN (virtual private network)
25220 @cindex virtual private network (VPN)
25222 The @code{(gnu services vpn)} module provides services related to
25223 @dfn{virtual private networks} (VPNs). It provides a @emph{client} service for
25224 your machine to connect to a VPN, and a @emph{server} service for your machine
25225 to host a VPN. Both services use @uref{https://openvpn.net/, OpenVPN}.
25227 @deffn {Scheme Procedure} openvpn-client-service @
25228 [#:config (openvpn-client-configuration)]
25230 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
25233 @deffn {Scheme Procedure} openvpn-server-service @
25234 [#:config (openvpn-server-configuration)]
25236 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
25238 Both can be run simultaneously.
25241 @c %automatically generated documentation
25243 Available @code{openvpn-client-configuration} fields are:
25245 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
25246 The OpenVPN package.
25250 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
25251 The OpenVPN pid file.
25253 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
25257 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
25258 The protocol (UDP or TCP) used to open a channel between clients and
25261 Defaults to @samp{udp}.
25265 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
25266 The device type used to represent the VPN connection.
25268 Defaults to @samp{tun}.
25272 If you do not have some of these files (eg.@: you use a username and
25273 password), you can disable any of the following three fields by setting
25274 it to @code{'disabled}.
25276 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
25277 The certificate authority to check connections against.
25279 Defaults to @samp{"/etc/openvpn/ca.crt"}.
25283 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
25284 The certificate of the machine the daemon is running on. It should be
25285 signed by the authority given in @code{ca}.
25287 Defaults to @samp{"/etc/openvpn/client.crt"}.
25291 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
25292 The key of the machine the daemon is running on. It must be the key whose
25293 certificate is @code{cert}.
25295 Defaults to @samp{"/etc/openvpn/client.key"}.
25299 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
25300 Whether to use the lzo compression algorithm.
25302 Defaults to @samp{#t}.
25306 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
25307 Don't re-read key files across SIGUSR1 or --ping-restart.
25309 Defaults to @samp{#t}.
25313 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
25314 Don't close and reopen TUN/TAP device or run up/down scripts across
25315 SIGUSR1 or --ping-restart restarts.
25317 Defaults to @samp{#t}.
25321 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
25322 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
25323 poll/epoll/select prior to the write operation.
25325 Defaults to @samp{#f}.
25328 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
25331 Defaults to @samp{3}.
25335 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
25336 Add an additional layer of HMAC authentication on top of the TLS control
25337 channel to protect against DoS attacks.
25339 Defaults to @samp{#f}.
25343 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
25344 Authenticate with server using username/password. The option is a file
25345 containing username/password on 2 lines. Do not use a file-like object as it
25346 would be added to the store and readable by any user.
25348 Defaults to @samp{'disabled}.
25351 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
25352 Whether to check the server certificate has server usage extension.
25354 Defaults to @samp{#t}.
25358 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
25359 Bind to a specific local port number.
25361 Defaults to @samp{#f}.
25365 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
25366 Retry resolving server address.
25368 Defaults to @samp{#t}.
25372 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
25373 A list of remote servers to connect to.
25375 Defaults to @samp{()}.
25377 Available @code{openvpn-remote-configuration} fields are:
25379 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
25382 Defaults to @samp{"my-server"}.
25386 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
25387 Port number the server listens to.
25389 Defaults to @samp{1194}.
25394 @c %end of automatic openvpn-client documentation
25396 @c %automatically generated documentation
25398 Available @code{openvpn-server-configuration} fields are:
25400 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
25401 The OpenVPN package.
25405 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
25406 The OpenVPN pid file.
25408 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
25412 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
25413 The protocol (UDP or TCP) used to open a channel between clients and
25416 Defaults to @samp{udp}.
25420 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
25421 The device type used to represent the VPN connection.
25423 Defaults to @samp{tun}.
25427 If you do not have some of these files (eg.@: you use a username and
25428 password), you can disable any of the following three fields by setting
25429 it to @code{'disabled}.
25431 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
25432 The certificate authority to check connections against.
25434 Defaults to @samp{"/etc/openvpn/ca.crt"}.
25438 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
25439 The certificate of the machine the daemon is running on. It should be
25440 signed by the authority given in @code{ca}.
25442 Defaults to @samp{"/etc/openvpn/client.crt"}.
25446 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
25447 The key of the machine the daemon is running on. It must be the key whose
25448 certificate is @code{cert}.
25450 Defaults to @samp{"/etc/openvpn/client.key"}.
25454 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
25455 Whether to use the lzo compression algorithm.
25457 Defaults to @samp{#t}.
25461 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
25462 Don't re-read key files across SIGUSR1 or --ping-restart.
25464 Defaults to @samp{#t}.
25468 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
25469 Don't close and reopen TUN/TAP device or run up/down scripts across
25470 SIGUSR1 or --ping-restart restarts.
25472 Defaults to @samp{#t}.
25476 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
25477 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
25478 poll/epoll/select prior to the write operation.
25480 Defaults to @samp{#f}.
25483 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
25486 Defaults to @samp{3}.
25490 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
25491 Add an additional layer of HMAC authentication on top of the TLS control
25492 channel to protect against DoS attacks.
25494 Defaults to @samp{#f}.
25498 @deftypevr {@code{openvpn-server-configuration} parameter} number port
25499 Specifies the port number on which the server listens.
25501 Defaults to @samp{1194}.
25505 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
25506 An ip and mask specifying the subnet inside the virtual network.
25508 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
25512 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
25513 A CIDR notation specifying the IPv6 subnet inside the virtual network.
25515 Defaults to @samp{#f}.
25519 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
25520 The Diffie-Hellman parameters file.
25522 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
25526 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
25527 The file that records client IPs.
25529 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
25533 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
25534 When true, the server will act as a gateway for its clients.
25536 Defaults to @samp{#f}.
25540 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
25541 When true, clients are allowed to talk to each other inside the VPN.
25543 Defaults to @samp{#f}.
25547 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
25548 Causes ping-like messages to be sent back and forth over the link so
25549 that each side knows when the other side has gone down. @code{keepalive}
25550 requires a pair. The first element is the period of the ping sending,
25551 and the second element is the timeout before considering the other side
25556 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
25557 The maximum number of clients.
25559 Defaults to @samp{100}.
25563 @deftypevr {@code{openvpn-server-configuration} parameter} string status
25564 The status file. This file shows a small report on current connection.
25565 It is truncated and rewritten every minute.
25567 Defaults to @samp{"/var/run/openvpn/status"}.
25571 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
25572 The list of configuration for some clients.
25574 Defaults to @samp{()}.
25576 Available @code{openvpn-ccd-configuration} fields are:
25578 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
25581 Defaults to @samp{"client"}.
25585 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
25588 Defaults to @samp{#f}.
25592 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
25595 Defaults to @samp{#f}.
25602 @c %end of automatic openvpn-server documentation
25605 @node Network File System
25606 @subsection Network File System
25609 The @code{(gnu services nfs)} module provides the following services,
25610 which are most commonly used in relation to mounting or exporting
25611 directory trees as @dfn{network file systems} (NFS).
25613 While it is possible to use the individual components that together make
25614 up a Network File System service, we recommended to configure an NFS
25615 server with the @code{nfs-service-type}.
25617 @subsubheading NFS Service
25618 @cindex NFS, server
25620 The NFS service takes care of setting up all NFS component services,
25621 kernel configuration file systems, and installs configuration files in
25622 the locations that NFS expects.
25624 @defvr {Scheme Variable} nfs-service-type
25625 A service type for a complete NFS server.
25628 @deftp {Data Type} nfs-configuration
25629 This data type represents the configuration of the NFS service and all
25632 It has the following parameters:
25634 @item @code{nfs-utils} (default: @code{nfs-utils})
25635 The nfs-utils package to use.
25637 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
25638 If a list of string values is provided, the @command{rpc.nfsd} daemon
25639 will be limited to supporting the given versions of the NFS protocol.
25641 @item @code{exports} (default: @code{'()})
25642 This is a list of directories the NFS server should export. Each entry
25643 is a list consisting of two elements: a directory name and a string
25644 containing all options. This is an example in which the directory
25645 @file{/export} is served to all NFS clients as a read-only share:
25651 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
25654 @item @code{rpcmountd-port} (default: @code{#f})
25655 The network port that the @command{rpc.mountd} daemon should use.
25657 @item @code{rpcstatd-port} (default: @code{#f})
25658 The network port that the @command{rpc.statd} daemon should use.
25660 @item @code{rpcbind} (default: @code{rpcbind})
25661 The rpcbind package to use.
25663 @item @code{idmap-domain} (default: @code{"localdomain"})
25664 The local NFSv4 domain name.
25666 @item @code{nfsd-port} (default: @code{2049})
25667 The network port that the @command{nfsd} daemon should use.
25669 @item @code{nfsd-threads} (default: @code{8})
25670 The number of threads used by the @command{nfsd} daemon.
25672 @item @code{nfsd-tcp?} (default: @code{#t})
25673 Whether the @command{nfsd} daemon should listen on a TCP socket.
25675 @item @code{nfsd-udp?} (default: @code{#f})
25676 Whether the @command{nfsd} daemon should listen on a UDP socket.
25678 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25679 The directory where the pipefs file system is mounted.
25681 @item @code{debug} (default: @code{'()"})
25682 A list of subsystems for which debugging output should be enabled. This
25683 is a list of symbols. Any of these symbols are valid: @code{nfsd},
25684 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
25688 If you don't need a complete NFS service or prefer to build it yourself
25689 you can use the individual component services that are documented below.
25691 @subsubheading RPC Bind Service
25694 The RPC Bind service provides a facility to map program numbers into
25695 universal addresses.
25696 Many NFS related services use this facility. Hence it is automatically
25697 started when a dependent service starts.
25699 @defvr {Scheme Variable} rpcbind-service-type
25700 A service type for the RPC portmapper daemon.
25704 @deftp {Data Type} rpcbind-configuration
25705 Data type representing the configuration of the RPC Bind Service.
25706 This type has the following parameters:
25708 @item @code{rpcbind} (default: @code{rpcbind})
25709 The rpcbind package to use.
25711 @item @code{warm-start?} (default: @code{#t})
25712 If this parameter is @code{#t}, then the daemon will read a
25713 state file on startup thus reloading state information saved by a previous
25719 @subsubheading Pipefs Pseudo File System
25723 The pipefs file system is used to transfer NFS related data
25724 between the kernel and user space programs.
25726 @defvr {Scheme Variable} pipefs-service-type
25727 A service type for the pipefs pseudo file system.
25730 @deftp {Data Type} pipefs-configuration
25731 Data type representing the configuration of the pipefs pseudo file system service.
25732 This type has the following parameters:
25734 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25735 The directory to which the file system is to be attached.
25740 @subsubheading GSS Daemon Service
25743 @cindex global security system
25745 The @dfn{global security system} (GSS) daemon provides strong security for RPC
25747 Before exchanging RPC requests an RPC client must establish a security
25748 context. Typically this is done using the Kerberos command @command{kinit}
25749 or automatically at login time using PAM services (@pxref{Kerberos Services}).
25751 @defvr {Scheme Variable} gss-service-type
25752 A service type for the Global Security System (GSS) daemon.
25755 @deftp {Data Type} gss-configuration
25756 Data type representing the configuration of the GSS daemon service.
25757 This type has the following parameters:
25759 @item @code{nfs-utils} (default: @code{nfs-utils})
25760 The package in which the @command{rpc.gssd} command is to be found.
25762 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25763 The directory where the pipefs file system is mounted.
25769 @subsubheading IDMAP Daemon Service
25771 @cindex name mapper
25773 The idmap daemon service provides mapping between user IDs and user names.
25774 Typically it is required in order to access file systems mounted via NFSv4.
25776 @defvr {Scheme Variable} idmap-service-type
25777 A service type for the Identity Mapper (IDMAP) daemon.
25780 @deftp {Data Type} idmap-configuration
25781 Data type representing the configuration of the IDMAP daemon service.
25782 This type has the following parameters:
25784 @item @code{nfs-utils} (default: @code{nfs-utils})
25785 The package in which the @command{rpc.idmapd} command is to be found.
25787 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
25788 The directory where the pipefs file system is mounted.
25790 @item @code{domain} (default: @code{#f})
25791 The local NFSv4 domain name.
25792 This must be a string or @code{#f}.
25793 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
25795 @item @code{verbosity} (default: @code{0})
25796 The verbosity level of the daemon.
25801 @node Continuous Integration
25802 @subsection Continuous Integration
25804 @cindex continuous integration
25805 @uref{https://git.savannah.gnu.org/cgit/guix/guix-cuirass.git, Cuirass} is a
25806 continuous integration tool for Guix. It can be used both for development and
25807 for providing substitutes to others (@pxref{Substitutes}).
25809 The @code{(gnu services cuirass)} module provides the following service.
25811 @defvr {Scheme Procedure} cuirass-service-type
25812 The type of the Cuirass service. Its value must be a
25813 @code{cuirass-configuration} object, as described below.
25816 To add build jobs, you have to set the @code{specifications} field of the
25817 configuration. Here is an example of a service that polls the Guix repository
25818 and builds the packages from a manifest. Some of the packages are defined in
25819 the @code{"custom-packages"} input, which is the equivalent of
25820 @env{GUIX_PACKAGE_PATH}.
25823 (define %cuirass-specs
25825 '((#:name . "my-manifest")
25826 (#:load-path-inputs . ("guix"))
25827 (#:package-path-inputs . ("custom-packages"))
25828 (#:proc-input . "guix")
25829 (#:proc-file . "build-aux/cuirass/gnu-system.scm")
25830 (#:proc . cuirass-jobs)
25831 (#:proc-args . ((subset . "manifests")
25832 (systems . ("x86_64-linux"))
25833 (manifests . (("config" . "guix/manifest.scm")))))
25834 (#:inputs . (((#:name . "guix")
25835 (#:url . "git://git.savannah.gnu.org/guix.git")
25836 (#:load-path . ".")
25837 (#:branch . "master")
25838 (#:no-compile? . #t))
25839 ((#:name . "config")
25840 (#:url . "https://git.example.org/config.git")
25841 (#:load-path . ".")
25842 (#:branch . "master")
25843 (#:no-compile? . #t))
25844 ((#:name . "custom-packages")
25845 (#:url . "https://git.example.org/custom-packages.git")
25846 (#:load-path . ".")
25847 (#:branch . "master")
25848 (#:no-compile? . #t)))))))
25850 (service cuirass-service-type
25851 (cuirass-configuration
25852 (specifications %cuirass-specs)))
25855 While information related to build jobs is located directly in the
25856 specifications, global settings for the @command{cuirass} process are
25857 accessible in other @code{cuirass-configuration} fields.
25859 @deftp {Data Type} cuirass-configuration
25860 Data type representing the configuration of Cuirass.
25863 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
25864 Location of the log file.
25866 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
25867 Location of the log file used by the web interface.
25869 @item @code{queries-log-file} (default: @code{#f})
25870 Location of the SQL queries log file. By default, SQL queries logging is
25873 @item @code{web-queries-log-file} (default: @code{#f})
25874 Location of the web SQL queries log file. By default, web SQL queries
25875 logging is disabled.
25877 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
25878 Location of the repository cache.
25880 @item @code{user} (default: @code{"cuirass"})
25881 Owner of the @code{cuirass} process.
25883 @item @code{group} (default: @code{"cuirass"})
25884 Owner's group of the @code{cuirass} process.
25886 @item @code{interval} (default: @code{60})
25887 Number of seconds between the poll of the repositories followed by the
25890 @item @code{queue-size} (default: @code{1})
25891 Size of the database writer queue.
25893 @item @code{database} (default: @code{"/var/lib/cuirass/cuirass.db"})
25894 Location of sqlite database which contains the build results and previously
25895 added specifications.
25897 @item @code{ttl} (default: @code{(* 30 24 3600)})
25898 Specifies the time-to-live (TTL) in seconds of garbage collector roots that
25899 are registered for build results. This means that build results are protected
25900 from garbage collection for at least @var{ttl} seconds.
25902 @item @code{port} (default: @code{8081})
25903 Port number used by the HTTP server.
25905 @item @code{host} (default: @code{"localhost"})
25906 Listen on the network interface for @var{host}. The default is to
25907 accept connections from localhost.
25909 @item @code{specifications} (default: @code{#~'()})
25910 A gexp (@pxref{G-Expressions}) that evaluates to a list of specifications,
25911 where a specification is an association list
25912 (@pxref{Associations Lists,,, guile, GNU Guile Reference Manual}) whose
25913 keys are keywords (@code{#:keyword-example}) as shown in the example
25916 @item @code{use-substitutes?} (default: @code{#f})
25917 This allows using substitutes to avoid building every dependencies of a job
25920 @item @code{one-shot?} (default: @code{#f})
25921 Only evaluate specifications and build derivations once.
25923 @item @code{fallback?} (default: @code{#f})
25924 When substituting a pre-built binary fails, fall back to building
25927 @item @code{extra-options} (default: @code{'()})
25928 Extra options to pass when running the Cuirass processes.
25930 @item @code{cuirass} (default: @code{cuirass})
25931 The Cuirass package to use.
25935 @node Power Management Services
25936 @subsection Power Management Services
25939 @cindex power management with TLP
25940 @subsubheading TLP daemon
25942 The @code{(gnu services pm)} module provides a Guix service definition
25943 for the Linux power management tool TLP.
25945 TLP enables various powersaving modes in userspace and kernel.
25946 Contrary to @code{upower-service}, it is not a passive,
25947 monitoring tool, as it will apply custom settings each time a new power
25948 source is detected. More information can be found at
25949 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
25951 @deffn {Scheme Variable} tlp-service-type
25952 The service type for the TLP tool. The default settings are optimised
25953 for battery life on most systems, but you can tweak them to your heart's
25954 content by adding a valid @code{tlp-configuration}:
25956 (service tlp-service-type
25958 (cpu-scaling-governor-on-ac (list "performance"))
25959 (sched-powersave-on-bat? #t)))
25963 Each parameter definition is preceded by its type; for example,
25964 @samp{boolean foo} indicates that the @code{foo} parameter
25965 should be specified as a boolean. Types starting with
25966 @code{maybe-} denote parameters that won't show up in TLP config file
25967 when their value is @code{'disabled}.
25969 @c The following documentation was initially generated by
25970 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
25971 @c documentation is better, so we shouldn't hesitate to edit below as
25972 @c needed. However if the change you want to make to this documentation
25973 @c can be done in an automated way, it's probably easier to change
25974 @c (generate-documentation) than to make it below and have to deal with
25975 @c the churn as TLP updates.
25977 Available @code{tlp-configuration} fields are:
25979 @deftypevr {@code{tlp-configuration} parameter} package tlp
25984 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
25985 Set to true if you wish to enable TLP.
25987 Defaults to @samp{#t}.
25991 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
25992 Default mode when no power supply can be detected. Alternatives are AC
25995 Defaults to @samp{"AC"}.
25999 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
26000 Number of seconds Linux kernel has to wait after the disk goes idle,
26001 before syncing on AC.
26003 Defaults to @samp{0}.
26007 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
26008 Same as @code{disk-idle-ac} but on BAT mode.
26010 Defaults to @samp{2}.
26014 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
26015 Dirty pages flushing periodicity, expressed in seconds.
26017 Defaults to @samp{15}.
26021 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
26022 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
26024 Defaults to @samp{60}.
26028 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
26029 CPU frequency scaling governor on AC mode. With intel_pstate driver,
26030 alternatives are powersave and performance. With acpi-cpufreq driver,
26031 alternatives are ondemand, powersave, performance and conservative.
26033 Defaults to @samp{disabled}.
26037 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
26038 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
26040 Defaults to @samp{disabled}.
26044 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
26045 Set the min available frequency for the scaling governor on AC.
26047 Defaults to @samp{disabled}.
26051 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
26052 Set the max available frequency for the scaling governor on AC.
26054 Defaults to @samp{disabled}.
26058 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
26059 Set the min available frequency for the scaling governor on BAT.
26061 Defaults to @samp{disabled}.
26065 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
26066 Set the max available frequency for the scaling governor on BAT.
26068 Defaults to @samp{disabled}.
26072 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
26073 Limit the min P-state to control the power dissipation of the CPU, in AC
26074 mode. Values are stated as a percentage of the available performance.
26076 Defaults to @samp{disabled}.
26080 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
26081 Limit the max P-state to control the power dissipation of the CPU, in AC
26082 mode. Values are stated as a percentage of the available performance.
26084 Defaults to @samp{disabled}.
26088 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
26089 Same as @code{cpu-min-perf-on-ac} on BAT mode.
26091 Defaults to @samp{disabled}.
26095 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
26096 Same as @code{cpu-max-perf-on-ac} on BAT mode.
26098 Defaults to @samp{disabled}.
26102 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
26103 Enable CPU turbo boost feature on AC mode.
26105 Defaults to @samp{disabled}.
26109 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
26110 Same as @code{cpu-boost-on-ac?} on BAT mode.
26112 Defaults to @samp{disabled}.
26116 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
26117 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
26118 used under light load conditions.
26120 Defaults to @samp{#f}.
26124 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
26125 Same as @code{sched-powersave-on-ac?} but on BAT mode.
26127 Defaults to @samp{#t}.
26131 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
26132 Enable Linux kernel NMI watchdog.
26134 Defaults to @samp{#f}.
26138 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
26139 For Linux kernels with PHC patch applied, change CPU voltages. An
26140 example value would be @samp{"F:V F:V F:V F:V"}.
26142 Defaults to @samp{disabled}.
26146 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
26147 Set CPU performance versus energy saving policy on AC. Alternatives are
26148 performance, normal, powersave.
26150 Defaults to @samp{"performance"}.
26154 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
26155 Same as @code{energy-perf-policy-ac} but on BAT mode.
26157 Defaults to @samp{"powersave"}.
26161 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
26166 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
26167 Hard disk advanced power management level.
26171 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
26172 Same as @code{disk-apm-bat} but on BAT mode.
26176 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
26177 Hard disk spin down timeout. One value has to be specified for each
26178 declared hard disk.
26180 Defaults to @samp{disabled}.
26184 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
26185 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
26187 Defaults to @samp{disabled}.
26191 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
26192 Select IO scheduler for disk devices. One value has to be specified for
26193 each declared hard disk. Example alternatives are cfq, deadline and
26196 Defaults to @samp{disabled}.
26200 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
26201 SATA aggressive link power management (ALPM) level. Alternatives are
26202 min_power, medium_power, max_performance.
26204 Defaults to @samp{"max_performance"}.
26208 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
26209 Same as @code{sata-linkpwr-ac} but on BAT mode.
26211 Defaults to @samp{"min_power"}.
26215 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
26216 Exclude specified SATA host devices for link power management.
26218 Defaults to @samp{disabled}.
26222 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
26223 Enable Runtime Power Management for AHCI controller and disks on AC
26226 Defaults to @samp{disabled}.
26230 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
26231 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
26233 Defaults to @samp{disabled}.
26237 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
26238 Seconds of inactivity before disk is suspended.
26240 Defaults to @samp{15}.
26244 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
26245 PCI Express Active State Power Management level. Alternatives are
26246 default, performance, powersave.
26248 Defaults to @samp{"performance"}.
26252 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
26253 Same as @code{pcie-aspm-ac} but on BAT mode.
26255 Defaults to @samp{"powersave"}.
26259 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
26260 Radeon graphics clock speed level. Alternatives are low, mid, high,
26263 Defaults to @samp{"high"}.
26267 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
26268 Same as @code{radeon-power-ac} but on BAT mode.
26270 Defaults to @samp{"low"}.
26274 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
26275 Radeon dynamic power management method (DPM). Alternatives are battery,
26278 Defaults to @samp{"performance"}.
26282 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
26283 Same as @code{radeon-dpm-state-ac} but on BAT mode.
26285 Defaults to @samp{"battery"}.
26289 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
26290 Radeon DPM performance level. Alternatives are auto, low, high.
26292 Defaults to @samp{"auto"}.
26296 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
26297 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
26299 Defaults to @samp{"auto"}.
26303 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
26304 Wifi power saving mode.
26306 Defaults to @samp{#f}.
26310 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
26311 Same as @code{wifi-power-ac?} but on BAT mode.
26313 Defaults to @samp{#t}.
26317 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
26318 Disable wake on LAN.
26320 Defaults to @samp{#t}.
26324 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
26325 Timeout duration in seconds before activating audio power saving on
26326 Intel HDA and AC97 devices. A value of 0 disables power saving.
26328 Defaults to @samp{0}.
26332 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
26333 Same as @code{sound-powersave-ac} but on BAT mode.
26335 Defaults to @samp{1}.
26339 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
26340 Disable controller in powersaving mode on Intel HDA devices.
26342 Defaults to @samp{#t}.
26346 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
26347 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
26348 powered on again by releasing (and reinserting) the eject lever or by
26349 pressing the disc eject button on newer models.
26351 Defaults to @samp{#f}.
26355 @deftypevr {@code{tlp-configuration} parameter} string bay-device
26356 Name of the optical drive device to power off.
26358 Defaults to @samp{"sr0"}.
26362 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
26363 Runtime Power Management for PCI(e) bus devices. Alternatives are on
26366 Defaults to @samp{"on"}.
26370 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
26371 Same as @code{runtime-pm-ac} but on BAT mode.
26373 Defaults to @samp{"auto"}.
26377 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
26378 Runtime Power Management for all PCI(e) bus devices, except blacklisted
26381 Defaults to @samp{#t}.
26385 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
26386 Exclude specified PCI(e) device addresses from Runtime Power Management.
26388 Defaults to @samp{disabled}.
26392 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
26393 Exclude PCI(e) devices assigned to the specified drivers from Runtime
26398 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
26399 Enable USB autosuspend feature.
26401 Defaults to @samp{#t}.
26405 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
26406 Exclude specified devices from USB autosuspend.
26408 Defaults to @samp{disabled}.
26412 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
26413 Exclude WWAN devices from USB autosuspend.
26415 Defaults to @samp{#t}.
26419 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
26420 Include specified devices into USB autosuspend, even if they are already
26421 excluded by the driver or via @code{usb-blacklist-wwan?}.
26423 Defaults to @samp{disabled}.
26427 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
26428 Enable USB autosuspend before shutdown.
26430 Defaults to @samp{disabled}.
26434 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
26435 Restore radio device state (bluetooth, wifi, wwan) from previous
26436 shutdown on system startup.
26438 Defaults to @samp{#f}.
26443 @cindex CPU frequency scaling with thermald
26444 @subsubheading Thermald daemon
26446 The @code{(gnu services pm)} module provides an interface to
26447 thermald, a CPU frequency scaling service which helps prevent overheating.
26449 @defvr {Scheme Variable} thermald-service-type
26450 This is the service type for
26451 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
26452 Thermal Daemon, which is responsible for controlling the thermal state
26453 of processors and preventing overheating.
26456 @deftp {Data Type} thermald-configuration
26457 Data type representing the configuration of @code{thermald-service-type}.
26460 @item @code{ignore-cpuid-check?} (default: @code{#f})
26461 Ignore cpuid check for supported CPU models.
26463 @item @code{thermald} (default: @var{thermald})
26464 Package object of thermald.
26469 @node Audio Services
26470 @subsection Audio Services
26472 The @code{(gnu services audio)} module provides a service to start MPD
26473 (the Music Player Daemon).
26476 @subsubheading Music Player Daemon
26478 The Music Player Daemon (MPD) is a service that can play music while
26479 being controlled from the local machine or over the network by a variety
26482 The following example shows how one might run @code{mpd} as user
26483 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
26486 (service mpd-service-type
26492 @defvr {Scheme Variable} mpd-service-type
26493 The service type for @command{mpd}
26496 @deftp {Data Type} mpd-configuration
26497 Data type representing the configuration of @command{mpd}.
26500 @item @code{user} (default: @code{"mpd"})
26501 The user to run mpd as.
26503 @item @code{music-dir} (default: @code{"~/Music"})
26504 The directory to scan for music files.
26506 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
26507 The directory to store playlists.
26509 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
26510 The location of the music database.
26512 @item @code{state-file} (default: @code{"~/.mpd/state"})
26513 The location of the file that stores current MPD's state.
26515 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
26516 The location of the sticker database.
26518 @item @code{port} (default: @code{"6600"})
26519 The port to run mpd on.
26521 @item @code{address} (default: @code{"any"})
26522 The address that mpd will bind to. To use a Unix domain socket,
26523 an absolute path can be specified here.
26525 @item @code{outputs} (default: @code{"(list (mpd-output))"})
26526 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
26531 @deftp {Data Type} mpd-output
26532 Data type representing an @command{mpd} audio output.
26535 @item @code{name} (default: @code{"MPD"})
26536 The name of the audio output.
26538 @item @code{type} (default: @code{"pulse"})
26539 The type of audio output.
26541 @item @code{enabled?} (default: @code{#t})
26542 Specifies whether this audio output is enabled when MPD is started. By
26543 default, all audio outputs are enabled. This is just the default
26544 setting when there is no state file; with a state file, the previous
26547 @item @code{tags?} (default: @code{#t})
26548 If set to @code{#f}, then MPD will not send tags to this output. This
26549 is only useful for output plugins that can receive tags, for example the
26550 @code{httpd} output plugin.
26552 @item @code{always-on?} (default: @code{#f})
26553 If set to @code{#t}, then MPD attempts to keep this audio output always
26554 open. This may be useful for streaming servers, when you don’t want to
26555 disconnect all listeners even when playback is accidentally stopped.
26557 @item @code{mixer-type}
26558 This field accepts a symbol that specifies which mixer should be used
26559 for this audio output: the @code{hardware} mixer, the @code{software}
26560 mixer, the @code{null} mixer (allows setting the volume, but with no
26561 effect; this can be used as a trick to implement an external mixer
26562 External Mixer) or no mixer (@code{none}).
26564 @item @code{extra-options} (default: @code{'()})
26565 An association list of option symbols to string values to be appended to
26566 the audio output configuration.
26571 The following example shows a configuration of @code{mpd} that provides
26572 an HTTP audio streaming output.
26575 (service mpd-service-type
26583 `((encoder . "vorbis")
26584 (port . "8080"))))))))
26588 @node Virtualization Services
26589 @subsection Virtualization Services
26591 The @code{(gnu services virtualization)} module provides services for
26592 the libvirt and virtlog daemons, as well as other virtualization-related
26595 @subsubheading Libvirt daemon
26597 @code{libvirtd} is the server side daemon component of the libvirt
26598 virtualization management system. This daemon runs on host servers
26599 and performs required management tasks for virtualized guests.
26601 @deffn {Scheme Variable} libvirt-service-type
26602 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
26603 Its value must be a @code{libvirt-configuration}.
26606 (service libvirt-service-type
26607 (libvirt-configuration
26608 (unix-sock-group "libvirt")
26609 (tls-port "16555")))
26613 @c Auto-generated with (generate-libvirt-documentation)
26614 Available @code{libvirt-configuration} fields are:
26616 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
26621 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
26622 Flag listening for secure TLS connections on the public TCP/IP port.
26623 You must set @code{listen} for this to have any effect.
26625 It is necessary to setup a CA and issue server certificates before using
26628 Defaults to @samp{#t}.
26632 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
26633 Listen for unencrypted TCP connections on the public TCP/IP port. You must
26634 set @code{listen} for this to have any effect.
26636 Using the TCP socket requires SASL authentication by default. Only SASL
26637 mechanisms which support data encryption are allowed. This is
26638 DIGEST_MD5 and GSSAPI (Kerberos5).
26640 Defaults to @samp{#f}.
26644 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
26645 Port for accepting secure TLS connections. This can be a port number,
26648 Defaults to @samp{"16514"}.
26652 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
26653 Port for accepting insecure TCP connections. This can be a port number,
26656 Defaults to @samp{"16509"}.
26660 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
26661 IP address or hostname used for client connections.
26663 Defaults to @samp{"0.0.0.0"}.
26667 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
26668 Flag toggling mDNS advertisement of the libvirt service.
26670 Alternatively can disable for all services on a host by stopping the
26673 Defaults to @samp{#f}.
26677 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
26678 Default mDNS advertisement name. This must be unique on the immediate
26681 Defaults to @samp{"Virtualization Host <hostname>"}.
26685 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
26686 UNIX domain socket group ownership. This can be used to allow a
26687 'trusted' set of users access to management capabilities without
26690 Defaults to @samp{"root"}.
26694 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
26695 UNIX socket permissions for the R/O socket. This is used for monitoring
26698 Defaults to @samp{"0777"}.
26702 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
26703 UNIX socket permissions for the R/W socket. Default allows only root.
26704 If PolicyKit is enabled on the socket, the default will change to allow
26705 everyone (eg, 0777)
26707 Defaults to @samp{"0770"}.
26711 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
26712 UNIX socket permissions for the admin socket. Default allows only owner
26713 (root), do not change it unless you are sure to whom you are exposing
26716 Defaults to @samp{"0777"}.
26720 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
26721 The directory in which sockets will be found/created.
26723 Defaults to @samp{"/var/run/libvirt"}.
26727 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
26728 Authentication scheme for UNIX read-only sockets. By default socket
26729 permissions allow anyone to connect
26731 Defaults to @samp{"polkit"}.
26735 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
26736 Authentication scheme for UNIX read-write sockets. By default socket
26737 permissions only allow root. If PolicyKit support was compiled into
26738 libvirt, the default will be to use 'polkit' auth.
26740 Defaults to @samp{"polkit"}.
26744 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
26745 Authentication scheme for TCP sockets. If you don't enable SASL, then
26746 all TCP traffic is cleartext. Don't do this outside of a dev/test
26749 Defaults to @samp{"sasl"}.
26753 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
26754 Authentication scheme for TLS sockets. TLS sockets already have
26755 encryption provided by the TLS layer, and limited authentication is done
26758 It is possible to make use of any SASL authentication mechanism as well,
26759 by using 'sasl' for this option
26761 Defaults to @samp{"none"}.
26765 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
26766 API access control scheme.
26768 By default an authenticated user is allowed access to all APIs. Access
26769 drivers can place restrictions on this.
26771 Defaults to @samp{()}.
26775 @deftypevr {@code{libvirt-configuration} parameter} string key-file
26776 Server key file path. If set to an empty string, then no private key is
26779 Defaults to @samp{""}.
26783 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
26784 Server key file path. If set to an empty string, then no certificate is
26787 Defaults to @samp{""}.
26791 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
26792 Server key file path. If set to an empty string, then no CA certificate
26795 Defaults to @samp{""}.
26799 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
26800 Certificate revocation list path. If set to an empty string, then no
26803 Defaults to @samp{""}.
26807 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
26808 Disable verification of our own server certificates.
26810 When libvirtd starts it performs some sanity checks against its own
26813 Defaults to @samp{#f}.
26817 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
26818 Disable verification of client certificates.
26820 Client certificate verification is the primary authentication mechanism.
26821 Any client which does not present a certificate signed by the CA will be
26824 Defaults to @samp{#f}.
26828 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
26829 Whitelist of allowed x509 Distinguished Name.
26831 Defaults to @samp{()}.
26835 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
26836 Whitelist of allowed SASL usernames. The format for username depends on
26837 the SASL authentication mechanism.
26839 Defaults to @samp{()}.
26843 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
26844 Override the compile time default TLS priority string. The default is
26845 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
26846 is desired for libvirt to deviate from the global default settings.
26848 Defaults to @samp{"NORMAL"}.
26852 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
26853 Maximum number of concurrent client connections to allow over all
26856 Defaults to @samp{5000}.
26860 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
26861 Maximum length of queue of connections waiting to be accepted by the
26862 daemon. Note, that some protocols supporting retransmission may obey
26863 this so that a later reattempt at connection succeeds.
26865 Defaults to @samp{1000}.
26869 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
26870 Maximum length of queue of accepted but not yet authenticated clients.
26871 Set this to zero to turn this feature off
26873 Defaults to @samp{20}.
26877 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
26878 Number of workers to start up initially.
26880 Defaults to @samp{5}.
26884 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
26885 Maximum number of worker threads.
26887 If the number of active clients exceeds @code{min-workers}, then more
26888 threads are spawned, up to max_workers limit. Typically you'd want
26889 max_workers to equal maximum number of clients allowed.
26891 Defaults to @samp{20}.
26895 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
26896 Number of priority workers. If all workers from above pool are stuck,
26897 some calls marked as high priority (notably domainDestroy) can be
26898 executed in this pool.
26900 Defaults to @samp{5}.
26904 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
26905 Total global limit on concurrent RPC calls.
26907 Defaults to @samp{20}.
26911 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
26912 Limit on concurrent requests from a single client connection. To avoid
26913 one client monopolizing the server this should be a small fraction of
26914 the global max_requests and max_workers parameter.
26916 Defaults to @samp{5}.
26920 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
26921 Same as @code{min-workers} but for the admin interface.
26923 Defaults to @samp{1}.
26927 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
26928 Same as @code{max-workers} but for the admin interface.
26930 Defaults to @samp{5}.
26934 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
26935 Same as @code{max-clients} but for the admin interface.
26937 Defaults to @samp{5}.
26941 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
26942 Same as @code{max-queued-clients} but for the admin interface.
26944 Defaults to @samp{5}.
26948 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
26949 Same as @code{max-client-requests} but for the admin interface.
26951 Defaults to @samp{5}.
26955 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
26956 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
26958 Defaults to @samp{3}.
26962 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
26965 A filter allows to select a different logging level for a given category
26966 of logs. The format for a filter is one of:
26977 where @code{name} is a string which is matched against the category
26978 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
26979 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
26980 name in the filter can be a substring of the full category name, in
26981 order to match multiple similar categories), the optional @samp{"+"}
26982 prefix tells libvirt to log stack trace for each message matching name,
26983 and @code{x} is the minimal level where matching messages should be
27001 Multiple filters can be defined in a single filters statement, they just
27002 need to be separated by spaces.
27004 Defaults to @samp{"3:remote 4:event"}.
27008 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
27011 An output is one of the places to save logging information. The format
27012 for an output can be:
27016 output goes to stderr
27018 @item x:syslog:name
27019 use syslog for the output and use the given name as the ident
27021 @item x:file:file_path
27022 output to a file, with the given filepath
27025 output to journald logging system
27029 In all case the x prefix is the minimal level, acting as a filter
27046 Multiple outputs can be defined, they just need to be separated by
27049 Defaults to @samp{"3:stderr"}.
27053 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
27054 Allows usage of the auditing subsystem to be altered
27058 0: disable all auditing
27061 1: enable auditing, only if enabled on host
27064 2: enable auditing, and exit if disabled on host.
27068 Defaults to @samp{1}.
27072 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
27073 Send audit messages via libvirt logging infrastructure.
27075 Defaults to @samp{#f}.
27079 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
27080 Host UUID. UUID must not have all digits be the same.
27082 Defaults to @samp{""}.
27086 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
27087 Source to read host UUID.
27091 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
27094 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
27098 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
27101 Defaults to @samp{"smbios"}.
27105 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
27106 A keepalive message is sent to a client after @code{keepalive_interval}
27107 seconds of inactivity to check if the client is still responding. If
27108 set to -1, libvirtd will never send keepalive requests; however clients
27109 can still send them and the daemon will send responses.
27111 Defaults to @samp{5}.
27115 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
27116 Maximum number of keepalive messages that are allowed to be sent to the
27117 client without getting any response before the connection is considered
27120 In other words, the connection is automatically closed approximately
27121 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
27122 the last message received from the client. When @code{keepalive-count}
27123 is set to 0, connections will be automatically closed after
27124 @code{keepalive-interval} seconds of inactivity without sending any
27125 keepalive messages.
27127 Defaults to @samp{5}.
27131 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
27132 Same as above but for admin interface.
27134 Defaults to @samp{5}.
27138 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
27139 Same as above but for admin interface.
27141 Defaults to @samp{5}.
27145 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
27146 Timeout for Open vSwitch calls.
27148 The @code{ovs-vsctl} utility is used for the configuration and its
27149 timeout option is set by default to 5 seconds to avoid potential
27150 infinite waits blocking libvirt.
27152 Defaults to @samp{5}.
27156 @c %end of autogenerated docs
27158 @subsubheading Virtlog daemon
27159 The virtlogd service is a server side daemon component of libvirt that is
27160 used to manage logs from virtual machine consoles.
27162 This daemon is not used directly by libvirt client applications, rather it
27163 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
27164 standalone daemon, the main @code{libvirtd} daemon can be restarted without
27165 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
27166 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
27168 @deffn {Scheme Variable} virtlog-service-type
27169 This is the type of the virtlog daemon.
27170 Its value must be a @code{virtlog-configuration}.
27173 (service virtlog-service-type
27174 (virtlog-configuration
27175 (max-clients 1000)))
27179 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
27180 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
27182 Defaults to @samp{3}.
27186 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
27189 A filter allows to select a different logging level for a given category
27190 of logs The format for a filter is one of:
27201 where @code{name} is a string which is matched against the category
27202 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
27203 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
27204 be a substring of the full category name, in order to match multiple
27205 similar categories), the optional "+" prefix tells libvirt to log stack
27206 trace for each message matching name, and @code{x} is the minimal level
27207 where matching messages should be logged:
27224 Multiple filters can be defined in a single filters statement, they just
27225 need to be separated by spaces.
27227 Defaults to @samp{"3:remote 4:event"}.
27231 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
27234 An output is one of the places to save logging information The format
27235 for an output can be:
27239 output goes to stderr
27241 @item x:syslog:name
27242 use syslog for the output and use the given name as the ident
27244 @item x:file:file_path
27245 output to a file, with the given filepath
27248 output to journald logging system
27252 In all case the x prefix is the minimal level, acting as a filter
27269 Multiple outputs can be defined, they just need to be separated by
27272 Defaults to @samp{"3:stderr"}.
27276 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
27277 Maximum number of concurrent client connections to allow over all
27280 Defaults to @samp{1024}.
27284 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
27285 Maximum file size before rolling over.
27287 Defaults to @samp{2MB}
27291 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
27292 Maximum number of backup files to keep.
27294 Defaults to @samp{3}
27298 @anchor{transparent-emulation-qemu}
27299 @subsubheading Transparent Emulation with QEMU
27302 @cindex @code{binfmt_misc}
27303 @code{qemu-binfmt-service-type} provides support for transparent
27304 emulation of program binaries built for different architectures---e.g.,
27305 it allows you to transparently execute an ARMv7 program on an x86_64
27306 machine. It achieves this by combining the @uref{https://www.qemu.org,
27307 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
27308 This feature only allows you to emulate GNU/Linux on a different
27309 architecture, but see below for GNU/Hurd support.
27311 @defvr {Scheme Variable} qemu-binfmt-service-type
27312 This is the type of the QEMU/binfmt service for transparent emulation.
27313 Its value must be a @code{qemu-binfmt-configuration} object, which
27314 specifies the QEMU package to use as well as the architecture we want to
27318 (service qemu-binfmt-service-type
27319 (qemu-binfmt-configuration
27320 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
27323 In this example, we enable transparent emulation for the ARM and aarch64
27324 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
27325 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
27326 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
27329 @deftp {Data Type} qemu-binfmt-configuration
27330 This is the configuration for the @code{qemu-binfmt} service.
27333 @item @code{platforms} (default: @code{'()})
27334 The list of emulated QEMU platforms. Each item must be a @dfn{platform
27335 object} as returned by @code{lookup-qemu-platforms} (see below).
27337 @item @code{guix-support?} (default: @code{#t})
27338 When it is true, QEMU and all its dependencies are added to the build
27339 environment of @command{guix-daemon} (@pxref{Invoking guix-daemon,
27340 @option{--chroot-directory} option}). This allows the @code{binfmt_misc}
27341 handlers to be used within the build environment, which in turn means
27342 that you can transparently build programs for another architecture.
27344 For example, let's suppose you're on an x86_64 machine and you have this
27348 (service qemu-binfmt-service-type
27349 (qemu-binfmt-configuration
27350 (platforms (lookup-qemu-platforms "arm"))
27351 (guix-support? #t)))
27357 guix build -s armhf-linux inkscape
27361 and it will build Inkscape for ARMv7 @emph{as if it were a native
27362 build}, transparently using QEMU to emulate the ARMv7 CPU. Pretty handy
27363 if you'd like to test a package build for an architecture you don't have
27366 When @code{guix-support?} is set to @code{#f}, programs for other
27367 architectures can still be executed transparently, but invoking commands
27368 like @command{guix build -s armhf-linux @dots{}} will fail.
27370 @item @code{qemu} (default: @code{qemu})
27371 The QEMU package to use.
27375 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
27376 Return the list of QEMU platform objects corresponding to
27377 @var{platforms}@dots{}. @var{platforms} must be a list of strings
27378 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
27379 @code{"mips64el"}, and so on.
27382 @deffn {Scheme Procedure} qemu-platform? @var{obj}
27383 Return true if @var{obj} is a platform object.
27386 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
27387 Return the name of @var{platform}---a string such as @code{"arm"}.
27391 @subsubheading The Hurd in a Virtual Machine
27393 @cindex @code{hurd}
27397 Service @code{hurd-vm} provides support for running GNU/Hurd in a
27398 virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
27399 to be used on GNU/Linux and the given GNU/Hurd operating system
27400 configuration is cross-compiled. The virtual machine is a Shepherd
27401 service that can be referred to by the names @code{hurd-vm} and
27402 @code{childhurd} and be controlled with commands such as:
27406 herd stop childhurd
27409 When the service is running, you can view its console by connecting to
27410 it with a VNC client, for example with:
27413 guix environment --ad-hoc tigervnc-client -- \
27414 vncviewer localhost:5900
27417 The default configuration (see @code{hurd-vm-configuration} below)
27418 spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
27419 (the virtual machine emulator) redirects to port 10222 on the host.
27420 Thus, you can connect over SSH to the childhurd with:
27423 ssh root@@localhost -p 10022
27426 The childhurd is volatile and stateless: it starts with a fresh root
27427 file system every time you restart it. By default though, all the files
27428 under @file{/etc/childhurd} on the host are copied as is to the root
27429 file system of the childhurd when it boots. This allows you to
27430 initialize ``secrets'' inside the VM: SSH host keys, authorized
27431 substitute keys, and so on---see the explanation of @code{secret-root}
27434 @defvr {Scheme Variable} hurd-vm-service-type
27435 This is the type of the Hurd in a Virtual Machine service. Its value
27436 must be a @code{hurd-vm-configuration} object, which specifies the
27437 operating system (@pxref{operating-system Reference}) and the disk size
27438 for the Hurd Virtual Machine, the QEMU package to use as well as the
27439 options for running it.
27444 (service hurd-vm-service-type
27445 (hurd-vm-configuration
27446 (disk-size (* 5000 (expt 2 20))) ;5G
27447 (memory-size 1024))) ;1024MiB
27450 would create a disk image big enough to build GNU@tie{}Hello, with some
27454 @deftp {Data Type} hurd-vm-configuration
27455 The data type representing the configuration for
27456 @code{hurd-vm-service-type}.
27459 @item @code{os} (default: @var{%hurd-vm-operating-system})
27460 The operating system to instantiate. This default is bare-bones with a
27461 permissive OpenSSH secure shell daemon listening on port 2222
27462 (@pxref{Networking Services, @code{openssh-service-type}}).
27464 @item @code{qemu} (default: @code{qemu-minimal})
27465 The QEMU package to use.
27467 @item @code{image} (default: @var{hurd-vm-disk-image})
27468 The procedure used to build the disk-image built from this
27471 @item @code{disk-size} (default: @code{'guess})
27472 The size of the disk image.
27474 @item @code{memory-size} (default: @code{512})
27475 The memory size of the Virtual Machine in mebibytes.
27477 @item @code{options} (default: @code{'("--snapshot")})
27478 The extra options for running QEMU.
27480 @item @code{id} (default: @code{#f})
27481 If set, a non-zero positive integer used to parameterize Childhurd
27482 instances. It is appended to the service's name,
27483 e.g. @code{childhurd1}.
27485 @item @code{net-options} (default: @var{hurd-vm-net-options})
27486 The procedure used to produce the list of QEMU networking options.
27488 By default, it produces
27491 '("--device" "rtl8139,netdev=net0"
27492 "--netdev" "user,id=net0\
27493 ,hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004\
27494 ,hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222\
27495 ,hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900")
27498 with forwarded ports:
27501 @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
27502 @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
27503 @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
27506 @item @code{secret-root} (default: @file{/etc/childhurd})
27507 The root directory with out-of-band secrets to be installed into the
27508 childhurd once it runs. Childhurds are volatile which means that on
27509 every startup, secrets such as the SSH host keys and Guix signing key
27512 If the @file{/etc/childhurd} directory does not exist, the
27513 @code{secret-service} running in the Childhurd will be sent an empty
27516 By default, the service automatically populates @file{/etc/childhurd}
27517 with the following non-volatile secrets, unless they already exist:
27520 /etc/childhurd/etc/guix/acl
27521 /etc/childhurd/etc/guix/signing-key.pub
27522 /etc/childhurd/etc/guix/signing-key.sec
27523 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
27524 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
27525 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
27526 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
27529 These files are automatically sent to the guest Hurd VM when it boots,
27530 including permissions.
27532 @cindex childhurd, offloading
27533 @cindex Hurd, offloading
27534 Having these files in place means that only a couple of things are
27535 missing to allow the host to offload @code{i586-gnu} builds to the
27540 Authorizing the childhurd's key on the host so that the host accepts
27541 build results coming from the childhurd, which can be done like so:
27544 guix archive --authorize < \
27545 /etc/childhurd/etc/guix/signing-key.pub
27549 Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
27553 We're working towards making that happen automatically---get in touch
27554 with us at @email{guix-devel@@gnu.org} to discuss it!
27558 Note that by default the VM image is volatile, i.e., once stopped the
27559 contents are lost. If you want a stateful image instead, override the
27560 configuration's @code{image} and @code{options} without
27561 the @code{--snapshot} flag using something along these lines:
27564 (service hurd-vm-service-type
27565 (hurd-vm-configuration
27566 (image (const "/out/of/store/writable/hurd.img"))
27570 @subsubheading Ganeti
27575 This service is considered experimental. Configuration options may be changed
27576 in a backwards-incompatible manner, and not all features have been thorougly
27577 tested. Users of this service are encouraged to share their experience at
27578 @email{guix-devel@@gnu.org}.
27581 Ganeti is a virtual machine management system. It is designed to keep virtual
27582 machines running on a cluster of servers even in the event of hardware failures,
27583 and to make maintenance and recovery tasks easy. It consists of multiple
27584 services which are described later in this section. In addition to the Ganeti
27585 service, you will need the OpenSSH service (@pxref{Networking Services,
27586 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
27587 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
27588 and address (or use a DNS server).
27590 All nodes participating in a Ganeti cluster should have the same Ganeti and
27591 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
27592 cluster node that supports multiple storage backends, and installs the
27593 @code{debootstrap} and @code{guix} @dfn{OS providers}:
27596 (use-package-modules virtualization)
27597 (use-service-modules base ganeti networking ssh)
27600 (host-name "node1")
27601 (hosts-file (plain-file "hosts" (format #f "
27602 127.0.0.1 localhost
27605 192.168.1.200 ganeti.example.com
27606 192.168.1.201 node1.example.com node1
27607 192.168.1.202 node2.example.com node2
27610 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
27611 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
27612 (packages (append (map specification->package
27613 '("qemu" "lvm2" "drbd-utils" "ceph"
27614 ;; Add the debootstrap and guix OS providers.
27615 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
27618 (append (list (static-networking-service "eth0" "192.168.1.201"
27619 #:netmask "255.255.255.0"
27620 #:gateway "192.168.1.254"
27621 #:name-servers '("192.168.1.252"
27624 ;; Ganeti uses SSH to communicate between nodes.
27625 (service openssh-service-type
27626 (openssh-configuration
27627 (permit-root-login 'without-password)))
27629 (service ganeti-service-type
27630 (ganeti-configuration
27631 ;; This list specifies allowed file system paths
27632 ;; for storing virtual machine images.
27633 (file-storage-paths '("/srv/ganeti/file-storage"))
27634 ;; This variable configures a single "variant" for
27635 ;; both Debootstrap and Guix that works with KVM.
27636 (os %default-ganeti-os))))
27640 Users are advised to read the
27641 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
27642 administrators guide} to learn about the various cluster options and
27643 day-to-day operations. There is also a
27644 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
27645 describing how to configure and initialize a small cluster.
27647 @defvr {Scheme Variable} ganeti-service-type
27648 This is a service type that includes all the various services that Ganeti
27651 Its value is a @code{ganeti-configuration} object that defines the package
27652 to use for CLI operations, as well as configuration for the various daemons.
27653 Allowed file storage paths and available guest operating systems are also
27654 configured through this data type.
27657 @deftp {Data Type} ganeti-configuration
27658 The @code{ganeti} service takes the following configuration options:
27661 @item @code{ganeti} (default: @code{ganeti})
27662 The @code{ganeti} package to use. It will be installed to the system profile
27663 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
27664 that the value specified here does not affect the other services as each refer
27665 to a specific @code{ganeti} package (see below).
27667 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
27668 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
27669 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
27670 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
27671 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
27672 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
27673 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
27674 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
27675 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
27676 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
27678 These options control the various daemons and cron jobs that are distributed
27679 with Ganeti. The possible values for these are described in detail below.
27680 To override a setting, you must use the configuration type for that service:
27683 (service ganeti-service-type
27684 (ganeti-configuration
27685 (rapi-configuration
27686 (ganeti-rapi-configuration
27687 (interface "eth1"))))
27688 (watcher-configuration
27689 (ganeti-watcher-configuration
27690 (rapi-ip "10.0.0.1"))))
27693 @item @code{file-storage-paths} (default: @code{'()})
27694 List of allowed directories for file storage backend.
27696 @item @code{os} (default: @code{%default-ganeti-os})
27697 List of @code{<ganeti-os>} records.
27700 In essence @code{ganeti-service-type} is shorthand for declaring each service
27704 (service ganeti-noded-service-type)
27705 (service ganeti-confd-service-type)
27706 (service ganeti-wconfd-service-type)
27707 (service ganeti-luxid-service-type)
27708 (service ganeti-kvmd-service-type)
27709 (service ganeti-mond-service-type)
27710 (service ganeti-metad-service-type)
27711 (service ganeti-watcher-service-type)
27712 (service ganeti-cleaner-service-type)
27715 Plus a service extension for @code{etc-service-type} that configures the file
27716 storage backend and OS variants.
27720 @deftp {Data Type} ganeti-os
27721 This data type is suitable for passing to the @code{os} parameter of
27722 @code{ganeti-configuration}. It takes the following parameters:
27726 The name for this OS provider. It is only used to specify where the
27727 configuration ends up. Setting it to ``debootstrap'' will create
27728 @file{/etc/ganeti/instance-debootstrap}.
27730 @item @code{extension}
27731 The file extension for variants of this OS type. For example
27732 @file{.conf} or @file{.scm}.
27734 @item @code{variants} (default: @code{'()})
27735 List of @code{ganeti-os-variant} objects for this OS.
27740 @deftp {Data Type} ganeti-os-variant
27741 This is the data type for a Ganeti OS variant. It takes the following
27746 The name of this variant.
27748 @item @code{configuration}
27749 A configuration file for this variant.
27753 @defvr {Scheme Variable} %default-debootstrap-hooks
27754 This variable contains hooks to configure networking and the GRUB bootloader.
27757 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
27758 This variable contains a list of packages suitable for a fully-virtualized guest.
27761 @deftp {Data Type} debootstrap-configuration
27763 This data type creates configuration files suitable for the debootstrap OS provider.
27766 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
27767 When not @code{#f}, this must be a G-expression that specifies a directory with
27768 scripts that will run when the OS is installed. It can also be a list of
27769 @code{(name . file-like)} pairs. For example:
27772 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
27775 That will create a directory with one executable named @code{99-hello-world}
27776 and run it every time this variant is installed. If set to @code{#f}, hooks
27777 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
27778 @item @code{proxy} (default: @code{#f})
27779 Optional HTTP proxy to use.
27780 @item @code{mirror} (default: @code{#f})
27781 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
27782 The default varies depending on the distribution.
27783 @item @code{arch} (default: @code{#f})
27784 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
27785 on an AArch64 host. Default is to use the current system architecture.
27786 @item @code{suite} (default: @code{"stable"})
27787 When set, this must be a Debian distribution ``suite'' such as @code{buster}
27788 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
27789 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
27790 List of extra packages that will get installed by dpkg in addition
27791 to the minimal system.
27792 @item @code{components} (default: @code{#f})
27793 When set, must be a list of Debian repository ``components''. For example
27794 @code{'("main" "contrib")}.
27795 @item @code{generate-cache?} (default: @code{#t})
27796 Whether to automatically cache the generated debootstrap archive.
27797 @item @code{clean-cache} (default: @code{14})
27798 Discard the cache after this amount of days. Use @code{#f} to never
27800 @item @code{partition-style} (default: @code{'msdos})
27801 The type of partition to create. When set, it must be one of
27802 @code{'msdos}, @code{'none} or a string.
27803 @item @code{partition-alignment} (default: @code{2048})
27804 Alignment of the partition in sectors.
27808 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
27809 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
27810 takes two parameters: a name and a @code{debootstrap-configuration} object.
27813 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
27814 This is a helper procedure that creates a @code{ganeti-os} record. It takes
27815 a list of variants created with @code{debootstrap-variant}.
27818 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
27819 This is a helper procedure that creates a @code{ganeti-os-variant} record for
27820 use with the Guix OS provider. It takes a name and a G-expression that returns
27821 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
27822 Guix System configuration.
27825 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
27826 This is a helper procedure that creates a @code{ganeti-os} record. It
27827 takes a list of variants produced by @code{guix-variant}.
27830 @defvr {Scheme Variable} %default-debootstrap-variants
27831 This is a convenience variable to make the debootstrap provider work
27832 ``out of the box'' without users having to declare variants manually. It
27833 contains a single debootstrap variant with the default configuration:
27836 (list (debootstrap-variant
27838 (debootstrap-configuration)))
27842 @defvr {Scheme Variable} %default-guix-variants
27843 This is a convenience variable to make the Guix OS provider work without
27844 additional configuration. It creates a virtual machine that has an SSH
27845 server, a serial console, and authorizes the Ganeti hosts SSH keys.
27848 (list (guix-variant
27850 (file-append ganeti-instance-guix
27851 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
27855 Users can implement support for OS providers unbeknownst to Guix by extending
27856 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
27862 (extension ".conf")
27864 (list (ganeti-os-variant
27866 (configuration (plain-file "bar" "this is fine"))))))
27869 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
27870 to a file in the store with contents @code{this is fine}. It also creates
27871 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
27873 Obviously this may not work for all OS providers out there. If you find the
27874 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
27876 The rest of this section documents the various services that are included by
27877 @code{ganeti-service-type}.
27879 @defvr {Scheme Variable} ganeti-noded-service-type
27880 @command{ganeti-noded} is the daemon responsible for node-specific functions
27881 within the Ganeti system. The value of this service must be a
27882 @code{ganeti-noded-configuration} object.
27885 @deftp {Data Type} ganeti-noded-configuration
27886 This is the configuration for the @code{ganeti-noded} service.
27889 @item @code{ganeti} (default: @code{ganeti})
27890 The @code{ganeti} package to use for this service.
27892 @item @code{port} (default: @code{1811})
27893 The TCP port on which the node daemon listens for network requests.
27895 @item @code{address} (default: @code{"0.0.0.0"})
27896 The network address that the daemon will bind to. The default address means
27897 bind to all available addresses.
27899 @item @code{interface} (default: @code{#f})
27900 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
27901 that the daemon will bind to.
27903 @item @code{max-clients} (default: @code{20})
27904 This sets a limit on the maximum number of simultaneous client connections
27905 that the daemon will handle. Connections above this count are accepted, but
27906 no responses will be sent until enough connections have closed.
27908 @item @code{ssl?} (default: @code{#t})
27909 Whether to use SSL/TLS to encrypt network communications. The certificate
27910 is automatically provisioned by the cluster and can be rotated with
27911 @command{gnt-cluster renew-crypto}.
27913 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
27914 This can be used to provide a specific encryption key for TLS communications.
27916 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
27917 This can be used to provide a specific certificate for TLS communications.
27919 @item @code{debug?} (default: @code{#f})
27920 When true, the daemon performs additional logging for debugging purposes.
27921 Note that this will leak encryption details to the log files, use with caution.
27926 @defvr {Scheme Variable} ganeti-confd-service-type
27927 @command{ganeti-confd} answers queries related to the configuration of a
27928 Ganeti cluster. The purpose of this daemon is to have a highly available
27929 and fast way to query cluster configuration values. It is automatically
27930 active on all @dfn{master candidates}. The value of this service must be a
27931 @code{ganeti-confd-configuration} object.
27935 @deftp {Data Type} ganeti-confd-configuration
27936 This is the configuration for the @code{ganeti-confd} service.
27939 @item @code{ganeti} (default: @code{ganeti})
27940 The @code{ganeti} package to use for this service.
27942 @item @code{port} (default: @code{1814})
27943 The UDP port on which to listen for network requests.
27945 @item @code{address} (default: @code{"0.0.0.0"})
27946 Network address that the daemon will bind to.
27948 @item @code{debug?} (default: @code{#f})
27949 When true, the daemon performs additional logging for debugging purposes.
27954 @defvr {Scheme Variable} ganeti-wconfd-service-type
27955 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
27956 about the cluster configuration and is the only entity that can accept
27957 changes to it. All jobs that need to modify the configuration will do so
27958 by sending appropriate requests to this daemon. It only runs on the
27959 @dfn{master node} and will automatically disable itself on other nodes.
27961 The value of this service must be a
27962 @code{ganeti-wconfd-configuration} object.
27965 @deftp {Data Type} ganeti-wconfd-configuration
27966 This is the configuration for the @code{ganeti-wconfd} service.
27969 @item @code{ganeti} (default: @code{ganeti})
27970 The @code{ganeti} package to use for this service.
27972 @item @code{no-voting?} (default: @code{#f})
27973 The daemon will refuse to start if the majority of cluster nodes does not
27974 agree that it is running on the master node. Set to @code{#t} to start
27975 even if a quorum can not be reached (dangerous, use with caution).
27977 @item @code{debug?} (default: @code{#f})
27978 When true, the daemon performs additional logging for debugging purposes.
27983 @defvr {Scheme Variable} ganeti-luxid-service-type
27984 @command{ganeti-luxid} is a daemon used to answer queries related to the
27985 configuration and the current live state of a Ganeti cluster. Additionally,
27986 it is the authoritative daemon for the Ganeti job queue. Jobs can be
27987 submitted via this daemon and it schedules and starts them.
27989 It takes a @code{ganeti-luxid-configuration} object.
27992 @deftp {Data Type} ganeti-luxid-configuration
27993 This is the configuration for the @code{ganeti-wconfd} service.
27996 @item @code{ganeti} (default: @code{ganeti})
27997 The @code{ganeti} package to use for this service.
27999 @item @code{no-voting?} (default: @code{#f})
28000 The daemon will refuse to start if it cannot verify that the majority of
28001 cluster nodes believes that it is running on the master node. Set to
28002 @code{#t} to ignore such checks and start anyway (this can be dangerous).
28004 @item @code{debug?} (default: @code{#f})
28005 When true, the daemon performs additional logging for debugging purposes.
28010 @defvr {Scheme Variable} ganeti-rapi-service-type
28011 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
28012 the master node and can be used to perform cluster actions programmatically
28013 via a JSON-based RPC protocol.
28015 Most query operations are allowed without authentication (unless
28016 @var{require-authentication?} is set), whereas write operations require
28017 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
28018 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
28019 API documentation} for more information.
28021 The value of this service must be a @code{ganeti-rapi-configuration} object.
28024 @deftp {Data Type} ganeti-rapi-configuration
28025 This is the configuration for the @code{ganeti-rapi} service.
28028 @item @code{ganeti} (default: @code{ganeti})
28029 The @code{ganeti} package to use for this service.
28031 @item @code{require-authentication?} (default: @code{#f})
28032 Whether to require authentication even for read-only operations.
28034 @item @code{port} (default: @code{5080})
28035 The TCP port on which to listen to API requests.
28037 @item @code{address} (default: @code{"0.0.0.0"})
28038 The network address that the service will bind to. By default it listens
28039 on all configured addresses.
28041 @item @code{interface} (default: @code{#f})
28042 When set, it must specify a specific network interface such as @code{eth0}
28043 that the daemon will bind to.
28045 @item @code{max-clients} (default: @code{20})
28046 The maximum number of simultaneous client requests to handle. Further
28047 connections are allowed, but no responses are sent until enough connections
28050 @item @code{ssl?} (default: @code{#t})
28051 Whether to use SSL/TLS encryption on the RAPI port.
28053 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
28054 This can be used to provide a specific encryption key for TLS communications.
28056 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
28057 This can be used to provide a specific certificate for TLS communications.
28059 @item @code{debug?} (default: @code{#f})
28060 When true, the daemon performs additional logging for debugging purposes.
28061 Note that this will leak encryption details to the log files, use with caution.
28066 @defvr {Scheme Variable} ganeti-kvmd-service-type
28067 @command{ganeti-kvmd} is responsible for determining whether a given KVM
28068 instance was shut down by an administrator or a user. Normally Ganeti will
28069 restart an instance that was not stopped through Ganeti itself. If the
28070 cluster option @code{user_shutdown} is true, this daemon monitors the
28071 @code{QMP} socket provided by QEMU and listens for shutdown events, and
28072 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
28073 it shuts down gracefully by itself.
28075 It takes a @code{ganeti-kvmd-configuration} object.
28078 @deftp {Data Type} ganeti-kvmd-configuration
28081 @item @code{ganeti} (default: @code{ganeti})
28082 The @code{ganeti} package to use for this service.
28084 @item @code{debug?} (default: @code{#f})
28085 When true, the daemon performs additional logging for debugging purposes.
28090 @defvr {Scheme Variable} ganeti-mond-service-type
28091 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
28092 functionality. It is responsible for running data collectors and publish the
28093 collected information through a HTTP interface.
28095 It takes a @code{ganeti-mond-configuration} object.
28098 @deftp {Data Type} ganeti-mond-configuration
28101 @item @code{ganeti} (default: @code{ganeti})
28102 The @code{ganeti} package to use for this service.
28104 @item @code{port} (default: @code{1815})
28105 The port on which the daemon will listen.
28107 @item @code{address} (default: @code{"0.0.0.0"})
28108 The network address that the daemon will bind to. By default it binds to all
28109 available interfaces.
28111 @item @code{debug?} (default: @code{#f})
28112 When true, the daemon performs additional logging for debugging purposes.
28117 @defvr {Scheme Variable} ganeti-metad-service-type
28118 @command{ganeti-metad} is an optional daemon that can be used to provide
28119 information about the cluster to instances or OS install scripts.
28121 It takes a @code{ganeti-metad-configuration} object.
28124 @deftp {Data Type} ganeti-metad-configuration
28127 @item @code{ganeti} (default: @code{ganeti})
28128 The @code{ganeti} package to use for this service.
28130 @item @code{port} (default: @code{80})
28131 The port on which the daemon will listen.
28133 @item @code{address} (default: @code{#f})
28134 If set, the daemon will bind to this address only. If left unset, the behavior
28135 depends on the cluster configuration.
28137 @item @code{debug?} (default: @code{#f})
28138 When true, the daemon performs additional logging for debugging purposes.
28143 @defvr {Scheme Variable} ganeti-watcher-service-type
28144 @command{ganeti-watcher} is a script designed to run periodically and ensure
28145 the health of a cluster. It will automatically restart instances that have
28146 stopped without Ganeti's consent, and repairs DRBD links in case a node has
28147 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
28148 that are not running. If the cluster parameter @code{ensure_node_health}
28149 is set, the watcher will also shutdown instances and DRBD devices if the
28150 node it is running on is declared offline by known master candidates.
28152 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
28154 The service takes a @code{ganeti-watcher-configuration} object.
28157 @deftp {Data Type} ganeti-watcher-configuration
28160 @item @code{ganeti} (default: @code{ganeti})
28161 The @code{ganeti} package to use for this service.
28163 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
28164 How often to run the script. The default is every five minutes.
28166 @item @code{rapi-ip} (default: @code{#f})
28167 This option needs to be specified only if the RAPI daemon is configured to use
28168 a particular interface or address. By default the cluster address is used.
28170 @item @code{job-age} (default: @code{(* 6 3600)})
28171 Archive cluster jobs older than this age, specified in seconds. The default
28172 is 6 hours. This keeps @command{gnt-job list} manageable.
28174 @item @code{verify-disks?} (default: @code{#t})
28175 If this is @code{#f}, the watcher will not try to repair broken DRBD links
28176 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
28179 @item @code{debug?} (default: @code{#f})
28180 When @code{#t}, the script performs additional logging for debugging purposes.
28185 @defvr {Scheme Variable} ganeti-cleaner-service-type
28186 @command{ganeti-cleaner} is a script designed to run periodically and remove
28187 old files from the cluster. This service type controls two @dfn{cron jobs}:
28188 one intended for the master node that permanently purges old cluster jobs,
28189 and one intended for every node that removes expired X509 certificates, keys,
28190 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
28191 it is safe to include even on non-master nodes as it will disable itself as
28194 It takes a @code{ganeti-cleaner-configuration} object.
28197 @deftp {Data Type} ganeti-cleaner-configuration
28200 @item @code{ganeti} (default: @code{ganeti})
28201 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
28203 @item @code{master-schedule} (default: @code{"45 1 * * *"})
28204 How often to run the master cleaning job. The default is once per day, at
28207 @item @code{node-schedule} (default: @code{"45 2 * * *"})
28208 How often to run the node cleaning job. The default is once per day, at
28214 @node Version Control Services
28215 @subsection Version Control Services
28217 The @code{(gnu services version-control)} module provides a service to
28218 allow remote access to local Git repositories. There are three options:
28219 the @code{git-daemon-service}, which provides access to repositories via
28220 the @code{git://} unsecured TCP-based protocol, extending the
28221 @code{nginx} web server to proxy some requests to
28222 @code{git-http-backend}, or providing a web interface with
28223 @code{cgit-service-type}.
28225 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
28227 Return a service that runs @command{git daemon}, a simple TCP server to
28228 expose repositories over the Git protocol for anonymous access.
28230 The optional @var{config} argument should be a
28231 @code{<git-daemon-configuration>} object, by default it allows read-only
28232 access to exported@footnote{By creating the magic file
28233 @file{git-daemon-export-ok} in the repository directory.} repositories under
28238 @deftp {Data Type} git-daemon-configuration
28239 Data type representing the configuration for @code{git-daemon-service}.
28242 @item @code{package} (default: @code{git})
28243 Package object of the Git distributed version control system.
28245 @item @code{export-all?} (default: @code{#f})
28246 Whether to allow access for all Git repositories, even if they do not
28247 have the @file{git-daemon-export-ok} file.
28249 @item @code{base-path} (default: @file{/srv/git})
28250 Whether to remap all the path requests as relative to the given path.
28251 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
28252 @samp{example.com}, then if you later try to pull
28253 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
28254 path as @file{/srv/git/hello.git}.
28256 @item @code{user-path} (default: @code{#f})
28257 Whether to allow @code{~user} notation to be used in requests. When
28258 specified with empty string, requests to
28259 @indicateurl{git://host/~alice/foo} is taken as a request to access
28260 @code{foo} repository in the home directory of user @code{alice}. If
28261 @code{(user-path "@var{path}")} is specified, the same request is taken
28262 as a request to access @file{@var{path}/foo} repository in the home
28263 directory of user @code{alice}.
28265 @item @code{listen} (default: @code{'()})
28266 Whether to listen on specific IP addresses or hostnames, defaults to
28269 @item @code{port} (default: @code{#f})
28270 Whether to listen on an alternative port, which defaults to 9418.
28272 @item @code{whitelist} (default: @code{'()})
28273 If not empty, only allow access to this list of directories.
28275 @item @code{extra-options} (default: @code{'()})
28276 Extra options will be passed to @command{git daemon}, please run
28277 @command{man git-daemon} for more information.
28282 The @code{git://} protocol lacks authentication. When you pull from a
28283 repository fetched via @code{git://}, you don't know whether the data you
28284 receive was modified or is even coming from the specified host, and your
28285 connection is subject to eavesdropping. It's better to use an authenticated
28286 and encrypted transport, such as @code{https}. Although Git allows you
28287 to serve repositories using unsophisticated file-based web servers,
28288 there is a faster protocol implemented by the @code{git-http-backend}
28289 program. This program is the back-end of a proper Git web service. It
28290 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
28291 on running the necessary @code{fcgiwrap} daemon.
28293 Guix has a separate configuration data type for serving Git repositories
28296 @deftp {Data Type} git-http-configuration
28297 Data type representing the configuration for a future
28298 @code{git-http-service-type}; can currently be used to configure Nginx
28299 through @code{git-http-nginx-location-configuration}.
28302 @item @code{package} (default: @var{git})
28303 Package object of the Git distributed version control system.
28305 @item @code{git-root} (default: @file{/srv/git})
28306 Directory containing the Git repositories to expose to the world.
28308 @item @code{export-all?} (default: @code{#f})
28309 Whether to expose access for all Git repositories in @var{git-root},
28310 even if they do not have the @file{git-daemon-export-ok} file.
28312 @item @code{uri-path} (default: @samp{/git/})
28313 Path prefix for Git access. With the default @samp{/git/} prefix, this
28314 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
28315 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
28316 with this prefix are not passed on to this Git instance.
28318 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
28319 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
28324 There is no @code{git-http-service-type}, currently; instead you can
28325 create an @code{nginx-location-configuration} from a
28326 @code{git-http-configuration} and then add that location to a web
28329 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
28330 [config=(git-http-configuration)]
28331 Compute an @code{nginx-location-configuration} that corresponds to the
28332 given Git http configuration. An example nginx service definition to
28333 serve the default @file{/srv/git} over HTTPS might be:
28336 (service nginx-service-type
28337 (nginx-configuration
28340 (nginx-server-configuration
28341 (listen '("443 ssl"))
28342 (server-name "git.my-host.org")
28344 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
28345 (ssl-certificate-key
28346 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
28349 (git-http-nginx-location-configuration
28350 (git-http-configuration (uri-path "/"))))))))))
28353 This example assumes that you are using Let's Encrypt to get your TLS
28354 certificate. @xref{Certificate Services}. The default @code{certbot}
28355 service will redirect all HTTP traffic on @code{git.my-host.org} to
28356 HTTPS. You will also need to add an @code{fcgiwrap} proxy to your
28357 system services. @xref{Web Services}.
28360 @subsubheading Cgit Service
28362 @cindex Cgit service
28363 @cindex Git, web interface
28364 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
28365 repositories written in C.
28367 The following example will configure the service with default values.
28368 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
28371 (service cgit-service-type)
28374 The @code{file-object} type designates either a file-like object
28375 (@pxref{G-Expressions, file-like objects}) or a string.
28377 @c %start of fragment
28379 Available @code{cgit-configuration} fields are:
28381 @deftypevr {@code{cgit-configuration} parameter} package package
28386 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
28387 NGINX configuration.
28391 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
28392 Specifies a command which will be invoked to format the content of about
28393 pages (both top-level and for each repository).
28395 Defaults to @samp{""}.
28399 @deftypevr {@code{cgit-configuration} parameter} string agefile
28400 Specifies a path, relative to each repository path, which can be used to
28401 specify the date and time of the youngest commit in the repository.
28403 Defaults to @samp{""}.
28407 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
28408 Specifies a command that will be invoked for authenticating repository
28411 Defaults to @samp{""}.
28415 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
28416 Flag which, when set to @samp{age}, enables date ordering in the branch
28417 ref list, and when set @samp{name} enables ordering by branch name.
28419 Defaults to @samp{"name"}.
28423 @deftypevr {@code{cgit-configuration} parameter} string cache-root
28424 Path used to store the cgit cache entries.
28426 Defaults to @samp{"/var/cache/cgit"}.
28430 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
28431 Number which specifies the time-to-live, in minutes, for the cached
28432 version of repository pages accessed with a fixed SHA1.
28434 Defaults to @samp{-1}.
28438 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
28439 Number which specifies the time-to-live, in minutes, for the cached
28440 version of repository pages accessed without a fixed SHA1.
28442 Defaults to @samp{5}.
28446 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
28447 Number which specifies the time-to-live, in minutes, for the cached
28448 version of the repository summary page.
28450 Defaults to @samp{5}.
28454 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
28455 Number which specifies the time-to-live, in minutes, for the cached
28456 version of the repository index page.
28458 Defaults to @samp{5}.
28462 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
28463 Number which specifies the time-to-live, in minutes, for the result of
28464 scanning a path for Git repositories.
28466 Defaults to @samp{15}.
28470 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
28471 Number which specifies the time-to-live, in minutes, for the cached
28472 version of the repository about page.
28474 Defaults to @samp{15}.
28478 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
28479 Number which specifies the time-to-live, in minutes, for the cached
28480 version of snapshots.
28482 Defaults to @samp{5}.
28486 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
28487 The maximum number of entries in the cgit cache. When set to @samp{0},
28488 caching is disabled.
28490 Defaults to @samp{0}.
28494 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
28495 Sort items in the repo list case sensitively.
28497 Defaults to @samp{#t}.
28501 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
28502 List of common prefixes which, when combined with a repository URL,
28503 generates valid clone URLs for the repository.
28505 Defaults to @samp{()}.
28509 @deftypevr {@code{cgit-configuration} parameter} list clone-url
28510 List of @code{clone-url} templates.
28512 Defaults to @samp{()}.
28516 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
28517 Command which will be invoked to format commit messages.
28519 Defaults to @samp{""}.
28523 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
28524 Flag which, when set to @samp{date}, enables strict date ordering in the
28525 commit log, and when set to @samp{topo} enables strict topological
28528 Defaults to @samp{"git log"}.
28532 @deftypevr {@code{cgit-configuration} parameter} file-object css
28533 URL which specifies the css document to include in all cgit pages.
28535 Defaults to @samp{"/share/cgit/cgit.css"}.
28539 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
28540 Specifies a command which will be invoked to format names and email
28541 address of committers, authors, and taggers, as represented in various
28542 places throughout the cgit interface.
28544 Defaults to @samp{""}.
28548 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
28549 Flag which, when set to @samp{#t}, will make cgit generate a HTML
28550 fragment suitable for embedding in other HTML pages.
28552 Defaults to @samp{#f}.
28556 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
28557 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
28558 commit history graph to the left of the commit messages in the
28559 repository log page.
28561 Defaults to @samp{#f}.
28565 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
28566 Flag which, when set to @samp{#t}, allows all filter settings to be
28567 overridden in repository-specific cgitrc files.
28569 Defaults to @samp{#f}.
28573 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
28574 Flag which, when set to @samp{#t}, allows users to follow a file in the
28577 Defaults to @samp{#f}.
28581 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
28582 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
28585 Defaults to @samp{#t}.
28589 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
28590 Flag which, when set to @samp{#t}, will make cgit generate extra links
28591 "summary", "commit", "tree" for each repo in the repository index.
28593 Defaults to @samp{#f}.
28597 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
28598 Flag which, when set to @samp{#t}, will make cgit display the owner of
28599 each repo in the repository index.
28601 Defaults to @samp{#t}.
28605 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
28606 Flag which, when set to @samp{#t}, will make cgit print the number of
28607 modified files for each commit on the repository log page.
28609 Defaults to @samp{#f}.
28613 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
28614 Flag which, when set to @samp{#t}, will make cgit print the number of
28615 added and removed lines for each commit on the repository log page.
28617 Defaults to @samp{#f}.
28621 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
28622 Flag which, when set to @code{#t}, will make cgit display remote
28623 branches in the summary and refs views.
28625 Defaults to @samp{#f}.
28629 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
28630 Flag which, when set to @code{1}, will make cgit use the subject of the
28631 parent commit as link text when generating links to parent commits in
28634 Defaults to @samp{#f}.
28638 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
28639 Flag which, when set to @samp{#t}, will make cgit use the subject of the
28640 parent commit as link text when generating links to parent commits in
28643 Defaults to @samp{#f}.
28647 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
28648 Flag which, when set to @samp{#t}, will make cgit generate linenumber
28649 links for plaintext blobs printed in the tree view.
28651 Defaults to @samp{#t}.
28655 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
28656 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
28657 set any repo specific settings.
28659 Defaults to @samp{#f}.
28663 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
28664 URL used as link to a shortcut icon for cgit.
28666 Defaults to @samp{"/favicon.ico"}.
28670 @deftypevr {@code{cgit-configuration} parameter} string footer
28671 The content of the file specified with this option will be included
28672 verbatim at the bottom of all pages (i.e.@: it replaces the standard
28673 "generated by..."@: message).
28675 Defaults to @samp{""}.
28679 @deftypevr {@code{cgit-configuration} parameter} string head-include
28680 The content of the file specified with this option will be included
28681 verbatim in the HTML HEAD section on all pages.
28683 Defaults to @samp{""}.
28687 @deftypevr {@code{cgit-configuration} parameter} string header
28688 The content of the file specified with this option will be included
28689 verbatim at the top of all pages.
28691 Defaults to @samp{""}.
28695 @deftypevr {@code{cgit-configuration} parameter} file-object include
28696 Name of a configfile to include before the rest of the current config-
28699 Defaults to @samp{""}.
28703 @deftypevr {@code{cgit-configuration} parameter} string index-header
28704 The content of the file specified with this option will be included
28705 verbatim above the repository index.
28707 Defaults to @samp{""}.
28711 @deftypevr {@code{cgit-configuration} parameter} string index-info
28712 The content of the file specified with this option will be included
28713 verbatim below the heading on the repository index page.
28715 Defaults to @samp{""}.
28719 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
28720 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
28721 in the servers timezone.
28723 Defaults to @samp{#f}.
28727 @deftypevr {@code{cgit-configuration} parameter} file-object logo
28728 URL which specifies the source of an image which will be used as a logo
28731 Defaults to @samp{"/share/cgit/cgit.png"}.
28735 @deftypevr {@code{cgit-configuration} parameter} string logo-link
28736 URL loaded when clicking on the cgit logo image.
28738 Defaults to @samp{""}.
28742 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
28743 Command which will be invoked to format the Owner column of the main
28746 Defaults to @samp{""}.
28750 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
28751 Number of items to display in atom feeds view.
28753 Defaults to @samp{10}.
28757 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
28758 Number of entries to list per page in "log" view.
28760 Defaults to @samp{50}.
28764 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
28765 Number of commit message characters to display in "log" view.
28767 Defaults to @samp{80}.
28771 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
28772 Specifies the number of entries to list per page on the repository index
28775 Defaults to @samp{50}.
28779 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
28780 Specifies the maximum number of repo description characters to display
28781 on the repository index page.
28783 Defaults to @samp{80}.
28787 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
28788 Specifies the maximum size of a blob to display HTML for in KBytes.
28790 Defaults to @samp{0}.
28794 @deftypevr {@code{cgit-configuration} parameter} string max-stats
28795 Maximum statistics period. Valid values are @samp{week},@samp{month},
28796 @samp{quarter} and @samp{year}.
28798 Defaults to @samp{""}.
28802 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
28803 Mimetype for the specified filename extension.
28805 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
28806 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
28807 "image/png") (svg "image/svg+xml"))}.
28811 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
28812 Specifies the file to use for automatic mimetype lookup.
28814 Defaults to @samp{""}.
28818 @deftypevr {@code{cgit-configuration} parameter} string module-link
28819 Text which will be used as the formatstring for a hyperlink when a
28820 submodule is printed in a directory listing.
28822 Defaults to @samp{""}.
28826 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
28827 If set to the value @samp{#t} caching will be disabled.
28829 Defaults to @samp{#f}.
28833 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
28834 If set to @samp{#t} showing full author email addresses will be
28837 Defaults to @samp{#f}.
28841 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
28842 Flag which, when set to @samp{#t}, will make cgit omit the standard
28843 header on all pages.
28845 Defaults to @samp{#f}.
28849 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
28850 A list of subdirectories inside of @code{repository-directory}, relative
28851 to it, that should loaded as Git repositories. An empty list means that
28852 all subdirectories will be loaded.
28854 Defaults to @samp{()}.
28858 @deftypevr {@code{cgit-configuration} parameter} file-object readme
28859 Text which will be used as default value for @code{cgit-repo-readme}.
28861 Defaults to @samp{""}.
28865 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
28866 If set to @code{#t} and @code{repository-directory} is enabled, if any
28867 repositories are found with a suffix of @code{.git}, this suffix will be
28868 removed for the URL and name.
28870 Defaults to @samp{#f}.
28874 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
28875 Maximum number of files to consider when detecting renames.
28877 Defaults to @samp{-1}.
28881 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
28882 The way in which repositories in each section are sorted.
28884 Defaults to @samp{""}.
28888 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
28889 Text used as content for the @code{robots} meta-tag.
28891 Defaults to @samp{("noindex" "nofollow")}.
28895 @deftypevr {@code{cgit-configuration} parameter} string root-desc
28896 Text printed below the heading on the repository index page.
28898 Defaults to @samp{"a fast webinterface for the git dscm"}.
28902 @deftypevr {@code{cgit-configuration} parameter} string root-readme
28903 The content of the file specified with this option will be included
28904 verbatim below the ``about'' link on the repository index page.
28906 Defaults to @samp{""}.
28910 @deftypevr {@code{cgit-configuration} parameter} string root-title
28911 Text printed as heading on the repository index page.
28913 Defaults to @samp{""}.
28917 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
28918 If set to @samp{#t} and repository-directory is enabled,
28919 repository-directory will recurse into directories whose name starts
28920 with a period. Otherwise, repository-directory will stay away from such
28921 directories, considered as ``hidden''. Note that this does not apply to
28922 the @file{.git} directory in non-bare repos.
28924 Defaults to @samp{#f}.
28928 @deftypevr {@code{cgit-configuration} parameter} list snapshots
28929 Text which specifies the default set of snapshot formats that cgit
28930 generates links for.
28932 Defaults to @samp{()}.
28936 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
28937 Name of the directory to scan for repositories (represents
28940 Defaults to @samp{"/srv/git"}.
28944 @deftypevr {@code{cgit-configuration} parameter} string section
28945 The name of the current repository section - all repositories defined
28946 after this option will inherit the current section name.
28948 Defaults to @samp{""}.
28952 @deftypevr {@code{cgit-configuration} parameter} string section-sort
28953 Flag which, when set to @samp{1}, will sort the sections on the
28954 repository listing by name.
28956 Defaults to @samp{""}.
28960 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
28961 A number which, if defined prior to repository-directory, specifies how
28962 many path elements from each repo path to use as a default section name.
28964 Defaults to @samp{0}.
28968 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
28969 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
28972 Defaults to @samp{#f}.
28976 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
28977 Specifies a command which will be invoked to format plaintext blobs in
28980 Defaults to @samp{""}.
28984 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
28985 Specifies the number of branches to display in the repository ``summary''
28988 Defaults to @samp{10}.
28992 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
28993 Specifies the number of log entries to display in the repository
28996 Defaults to @samp{10}.
29000 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
29001 Specifies the number of tags to display in the repository ``summary''
29004 Defaults to @samp{10}.
29008 @deftypevr {@code{cgit-configuration} parameter} string strict-export
29009 Filename which, if specified, needs to be present within the repository
29010 for cgit to allow access to that repository.
29012 Defaults to @samp{""}.
29016 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
29017 URL which, if specified, will be used as root for all cgit links.
29019 Defaults to @samp{"/"}.
29023 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
29024 A list of @dfn{cgit-repo} records to use with config.
29026 Defaults to @samp{()}.
29028 Available @code{repository-cgit-configuration} fields are:
29030 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
29031 A mask of snapshot formats for this repo that cgit generates links for,
29032 restricted by the global @code{snapshots} setting.
29034 Defaults to @samp{()}.
29038 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
29039 Override the default @code{source-filter}.
29041 Defaults to @samp{""}.
29045 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
29046 The relative URL used to access the repository.
29048 Defaults to @samp{""}.
29052 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
29053 Override the default @code{about-filter}.
29055 Defaults to @samp{""}.
29059 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
29060 Flag which, when set to @samp{age}, enables date ordering in the branch
29061 ref list, and when set to @samp{name} enables ordering by branch name.
29063 Defaults to @samp{""}.
29067 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
29068 A list of URLs which can be used to clone repo.
29070 Defaults to @samp{()}.
29074 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
29075 Override the default @code{commit-filter}.
29077 Defaults to @samp{""}.
29081 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
29082 Flag which, when set to @samp{date}, enables strict date ordering in the
29083 commit log, and when set to @samp{topo} enables strict topological
29086 Defaults to @samp{""}.
29090 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
29091 The name of the default branch for this repository. If no such branch
29092 exists in the repository, the first branch name (when sorted) is used as
29093 default instead. By default branch pointed to by HEAD, or ``master'' if
29094 there is no suitable HEAD.
29096 Defaults to @samp{""}.
29100 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
29101 The value to show as repository description.
29103 Defaults to @samp{""}.
29107 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
29108 The value to show as repository homepage.
29110 Defaults to @samp{""}.
29114 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
29115 Override the default @code{email-filter}.
29117 Defaults to @samp{""}.
29121 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
29122 A flag which can be used to disable the global setting
29123 @code{enable-commit-graph?}.
29125 Defaults to @samp{disabled}.
29129 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
29130 A flag which can be used to disable the global setting
29131 @code{enable-log-filecount?}.
29133 Defaults to @samp{disabled}.
29137 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
29138 A flag which can be used to disable the global setting
29139 @code{enable-log-linecount?}.
29141 Defaults to @samp{disabled}.
29145 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
29146 Flag which, when set to @code{#t}, will make cgit display remote
29147 branches in the summary and refs views.
29149 Defaults to @samp{disabled}.
29153 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
29154 A flag which can be used to override the global setting
29155 @code{enable-subject-links?}.
29157 Defaults to @samp{disabled}.
29161 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
29162 A flag which can be used to override the global setting
29163 @code{enable-html-serving?}.
29165 Defaults to @samp{disabled}.
29169 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
29170 Flag which, when set to @code{#t}, hides the repository from the
29173 Defaults to @samp{#f}.
29177 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
29178 Flag which, when set to @samp{#t}, ignores the repository.
29180 Defaults to @samp{#f}.
29184 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
29185 URL which specifies the source of an image which will be used as a logo
29186 on this repo’s pages.
29188 Defaults to @samp{""}.
29192 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
29193 URL loaded when clicking on the cgit logo image.
29195 Defaults to @samp{""}.
29199 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
29200 Override the default @code{owner-filter}.
29202 Defaults to @samp{""}.
29206 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
29207 Text which will be used as the formatstring for a hyperlink when a
29208 submodule is printed in a directory listing. The arguments for the
29209 formatstring are the path and SHA1 of the submodule commit.
29211 Defaults to @samp{""}.
29215 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
29216 Text which will be used as the formatstring for a hyperlink when a
29217 submodule with the specified subdirectory path is printed in a directory
29220 Defaults to @samp{()}.
29224 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
29225 Override the default maximum statistics period.
29227 Defaults to @samp{""}.
29231 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
29232 The value to show as repository name.
29234 Defaults to @samp{""}.
29238 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
29239 A value used to identify the owner of the repository.
29241 Defaults to @samp{""}.
29245 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
29246 An absolute path to the repository directory.
29248 Defaults to @samp{""}.
29252 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
29253 A path (relative to repo) which specifies a file to include verbatim as
29254 the ``About'' page for this repo.
29256 Defaults to @samp{""}.
29260 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
29261 The name of the current repository section - all repositories defined
29262 after this option will inherit the current section name.
29264 Defaults to @samp{""}.
29268 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
29269 Extra options will be appended to cgitrc file.
29271 Defaults to @samp{()}.
29277 @deftypevr {@code{cgit-configuration} parameter} list extra-options
29278 Extra options will be appended to cgitrc file.
29280 Defaults to @samp{()}.
29285 @c %end of fragment
29287 However, it could be that you just want to get a @code{cgitrc} up and
29288 running. In that case, you can pass an @code{opaque-cgit-configuration}
29289 as a record to @code{cgit-service-type}. As its name indicates, an
29290 opaque configuration does not have easy reflective capabilities.
29292 Available @code{opaque-cgit-configuration} fields are:
29294 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
29298 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
29299 The contents of the @code{cgitrc}, as a string.
29302 For example, if your @code{cgitrc} is just the empty string, you
29303 could instantiate a cgit service like this:
29306 (service cgit-service-type
29307 (opaque-cgit-configuration
29311 @subsubheading Gitolite Service
29313 @cindex Gitolite service
29314 @cindex Git, hosting
29315 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
29316 repositories on a central server.
29318 Gitolite can handle multiple repositories and users, and supports flexible
29319 configuration of the permissions for the users on the repositories.
29321 The following example will configure Gitolite using the default @code{git}
29322 user, and the provided SSH public key.
29325 (service gitolite-service-type
29326 (gitolite-configuration
29327 (admin-pubkey (plain-file
29329 "ssh-rsa AAAA... guix@@example.com"))))
29332 Gitolite is configured through a special admin repository which you can clone,
29333 for example, if you setup Gitolite on @code{example.com}, you would run the
29334 following command to clone the admin repository.
29337 git clone git@@example.com:gitolite-admin
29340 When the Gitolite service is activated, the provided @code{admin-pubkey} will
29341 be inserted in to the @file{keydir} directory in the gitolite-admin
29342 repository. If this results in a change in the repository, it will be
29343 committed using the message ``gitolite setup by GNU Guix''.
29345 @deftp {Data Type} gitolite-configuration
29346 Data type representing the configuration for @code{gitolite-service-type}.
29349 @item @code{package} (default: @var{gitolite})
29350 Gitolite package to use.
29352 @item @code{user} (default: @var{git})
29353 User to use for Gitolite. This will be user that you use when accessing
29356 @item @code{group} (default: @var{git})
29357 Group to use for Gitolite.
29359 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
29360 Directory in which to store the Gitolite configuration and repositories.
29362 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
29363 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
29364 representing the configuration for Gitolite.
29366 @item @code{admin-pubkey} (default: @var{#f})
29367 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
29368 setup Gitolite. This will be inserted in to the @file{keydir} directory
29369 within the gitolite-admin repository.
29371 To specify the SSH key as a string, use the @code{plain-file} function.
29374 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
29380 @deftp {Data Type} gitolite-rc-file
29381 Data type representing the Gitolite RC file.
29384 @item @code{umask} (default: @code{#o0077})
29385 This controls the permissions Gitolite sets on the repositories and their
29388 A value like @code{#o0027} will give read access to the group used by Gitolite
29389 (by default: @code{git}). This is necessary when using Gitolite with software
29390 like cgit or gitweb.
29392 @item @code{git-config-keys} (default: @code{""})
29393 Gitolite allows you to set git config values using the @samp{config}
29394 keyword. This setting allows control over the config keys to accept.
29396 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
29397 Set the role names allowed to be used by users running the perms command.
29399 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
29400 This setting controls the commands and features to enable within Gitolite.
29406 @node Game Services
29407 @subsection Game Services
29409 @subsubheading The Battle for Wesnoth Service
29411 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
29412 based tactical strategy game, with several single player campaigns, and
29413 multiplayer games (both networked and local).
29415 @defvar {Scheme Variable} wesnothd-service-type
29416 Service type for the wesnothd service. Its value must be a
29417 @code{wesnothd-configuration} object. To run wesnothd in the default
29418 configuration, instantiate it as:
29421 (service wesnothd-service-type)
29425 @deftp {Data Type} wesnothd-configuration
29426 Data type representing the configuration of @command{wesnothd}.
29429 @item @code{package} (default: @code{wesnoth-server})
29430 The wesnoth server package to use.
29432 @item @code{port} (default: @code{15000})
29433 The port to bind the server to.
29438 @node PAM Mount Service
29439 @subsection PAM Mount Service
29442 The @code{(gnu services pam-mount)} module provides a service allowing
29443 users to mount volumes when they log in. It should be able to mount any
29444 volume format supported by the system.
29446 @defvar {Scheme Variable} pam-mount-service-type
29447 Service type for PAM Mount support.
29450 @deftp {Data Type} pam-mount-configuration
29451 Data type representing the configuration of PAM Mount.
29453 It takes the following parameters:
29457 The configuration rules that will be used to generate
29458 @file{/etc/security/pam_mount.conf.xml}.
29460 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
29461 Guile Reference Manual}), and the default ones don't mount anything for
29465 `((debug (@@ (enable "0")))
29466 (mntoptions (@@ (allow ,(string-join
29467 '("nosuid" "nodev" "loop"
29468 "encryption" "fsck" "nonempty"
29469 "allow_root" "allow_other")
29471 (mntoptions (@@ (require "nosuid,nodev")))
29472 (logout (@@ (wait "0")
29476 (mkmountpoint (@@ (enable "1")
29480 Some @code{volume} elements must be added to automatically mount volumes
29481 at login. Here's an example allowing the user @code{alice} to mount her
29482 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
29483 the partition where he stores his data:
29486 (define pam-mount-rules
29487 `((debug (@@ (enable "0")))
29488 (volume (@@ (user "alice")
29491 (mountpoint "/home/alice")))
29492 (volume (@@ (user "bob")
29495 (mountpoint "/home/bob/data")
29496 (options "defaults,autodefrag,compress")))
29497 (mntoptions (@@ (allow ,(string-join
29498 '("nosuid" "nodev" "loop"
29499 "encryption" "fsck" "nonempty"
29500 "allow_root" "allow_other")
29502 (mntoptions (@@ (require "nosuid,nodev")))
29503 (logout (@@ (wait "0")
29507 (mkmountpoint (@@ (enable "1")
29508 (remove "true")))))
29510 (service pam-mount-service-type
29511 (pam-mount-configuration
29512 (rules pam-mount-rules)))
29515 The complete list of possible options can be found in the man page for
29516 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
29521 @node Guix Services
29522 @subsection Guix Services
29524 @subsubheading Guix Build Coordinator
29525 The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
29526 Coordinator} aids in distributing derivation builds among machines
29527 running an @dfn{agent}. The build daemon is still used to build the
29528 derivations, but the Guix Build Coordinator manages allocating builds
29529 and working with the results.
29532 This service is considered experimental. Configuration options may be
29533 changed in a backwards-incompatible manner, and not all features have
29534 been thorougly tested.
29537 The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
29538 more connected @dfn{agent} processes. The coordinator process handles
29539 clients submitting builds, and allocating builds to agents. The agent
29540 processes talk to a build daemon to actually perform the builds, then
29541 send the results back to the coordinator.
29543 There is a script to run the coordinator component of the Guix Build
29544 Coordinator, but the Guix service uses a custom Guile script instead, to
29545 provide better integration with G-expressions used in the configuration.
29547 @defvar {Scheme Variable} guix-build-coordinator-service-type
29548 Service type for the Guix Build Coordinator. Its value must be a
29549 @code{guix-build-coordinator-configuration} object.
29552 @deftp {Data Type} guix-build-coordinator-configuration
29553 Data type representing the configuration of the Guix Build Coordinator.
29556 @item @code{package} (default: @code{guix-build-coordinator})
29557 The Guix Build Coordinator package to use.
29559 @item @code{user} (default: @code{"guix-build-coordinator"})
29560 The system user to run the service as.
29562 @item @code{group} (default: @code{"guix-build-coordinator"})
29563 The system group to run the service as.
29565 @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
29566 The URI to use for the database.
29568 @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
29569 The URI describing how to listen to requests from agent processes.
29571 @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
29572 The URI describing how to listen to requests from clients. The client
29573 API allows submitting builds and currently isn't authenticated, so take
29574 care when configuring this value.
29576 @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
29577 A G-expression for the allocation strategy to be used. This is a
29578 procedure that takes the datastore as an argument and populates the
29579 allocation plan in the database.
29581 @item @code{hooks} (default: @var{'()})
29582 An association list of hooks. These provide a way to execute arbitrary
29583 code upon certain events, like a build result being processed.
29585 @item @code{guile} (default: @code{guile-3.0-latest})
29586 The Guile package with which to run the Guix Build Coordinator.
29591 @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
29592 Service type for a Guix Build Coordinator agent. Its value must be a
29593 @code{guix-build-coordinator-agent-configuration} object.
29596 @deftp {Data Type} guix-build-coordinator-agent-configuration
29597 Data type representing the configuration a Guix Build Coordinator agent.
29600 @item @code{package} (default: @code{guix-build-coordinator})
29601 The Guix Build Coordinator package to use.
29603 @item @code{user} (default: @code{"guix-build-coordinator-agent"})
29604 The system user to run the service as.
29606 @item @code{coordinator} (default: @code{"http://localhost:8745"})
29607 The URI to use when connecting to the coordinator.
29610 The UUID of the agent. This should be generated by the coordinator
29611 process, stored in the coordinator database, and used by the intended
29614 @item @code{password} (default: @code{#f})
29615 The password to use when connecting to the coordinator. A file to read
29616 the password from can also be specified, and this is more secure.
29618 @item @code{password-file} (default: @code{#f})
29619 A file containing the password to use when connecting to the
29622 @item @code{systems} (default: @code{#f})
29623 The systems for which this agent should fetch builds. The agent process
29624 will use the current system it's running on as the default.
29626 @item @code{max-parallel-builds} (default: @code{1})
29627 The number of builds to perform in parallel.
29629 @item @code{derivation-substitute-urls} (default: @code{#f})
29630 URLs from which to attempt to fetch substitutes for derivations, if the
29631 derivations aren't already available.
29633 @item @code{non-derivation-substitute-urls} (default: @code{#f})
29634 URLs from which to attempt to fetch substitutes for build inputs, if the
29635 input store items aren't already available.
29640 The Guix Build Coordinator package contains a script to query an
29641 instance of the Guix Data Service for derivations to build, and then
29642 submit builds for those derivations to the coordinator. The service
29643 type below assists in running this script. This is an additional tool
29644 that may be useful when building derivations contained within an
29645 instance of the Guix Data Service.
29647 @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
29648 Service type for the
29649 guix-build-coordinator-queue-builds-from-guix-data-service script. Its
29650 value must be a @code{guix-build-coordinator-queue-builds-configuration}
29654 @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
29655 Data type representing the options to the queue builds from guix data
29659 @item @code{package} (default: @code{guix-build-coordinator})
29660 The Guix Build Coordinator package to use.
29662 @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
29663 The system user to run the service as.
29665 @item @code{coordinator} (default: @code{"http://localhost:8745"})
29666 The URI to use when connecting to the coordinator.
29668 @item @code{systems} (default: @code{#f})
29669 The systems for which to fetch derivations to build.
29671 @item @code{systems-and-targets} (default: @code{#f})
29672 An association list of system and target pairs for which to fetch
29673 derivations to build.
29675 @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
29676 The Guix Data Service instance from which to query to find out about
29677 derivations to build.
29679 @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
29680 A file to record which commits have been processed, to avoid needlessly
29681 processing them again if the service is restarted.
29686 @subsubheading Guix Data Service
29687 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
29688 and provides data about GNU Guix. This includes information about
29689 packages, derivations and lint warnings.
29691 The data is stored in a PostgreSQL database, and available through a web
29694 @defvar {Scheme Variable} guix-data-service-type
29695 Service type for the Guix Data Service. Its value must be a
29696 @code{guix-data-service-configuration} object. The service optionally
29697 extends the getmail service, as the guix-commits mailing list is used to
29698 find out about changes in the Guix git repository.
29701 @deftp {Data Type} guix-data-service-configuration
29702 Data type representing the configuration of the Guix Data Service.
29705 @item @code{package} (default: @code{guix-data-service})
29706 The Guix Data Service package to use.
29708 @item @code{user} (default: @code{"guix-data-service"})
29709 The system user to run the service as.
29711 @item @code{group} (default: @code{"guix-data-service"})
29712 The system group to run the service as.
29714 @item @code{port} (default: @code{8765})
29715 The port to bind the web service to.
29717 @item @code{host} (default: @code{"127.0.0.1"})
29718 The host to bind the web service to.
29720 @item @code{getmail-idle-mailboxes} (default: @code{#f})
29721 If set, this is the list of mailboxes that the getmail service will be
29722 configured to listen to.
29724 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
29725 If set, this is the @code{getmail-retriever-configuration} object with
29726 which to configure getmail to fetch mail from the guix-commits mailing
29729 @item @code{extra-options} (default: @var{'()})
29730 Extra command line options for @code{guix-data-service}.
29732 @item @code{extra-process-jobs-options} (default: @var{'()})
29733 Extra command line options for @code{guix-data-service-process-jobs}.
29738 @node Linux Services
29739 @subsection Linux Services
29742 @cindex out of memory killer
29744 @cindex early out of memory daemon
29745 @subsubheading Early OOM Service
29747 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
29748 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
29749 space and provides a more responsive and configurable alternative to the
29750 in-kernel OOM killer. It is useful to prevent the system from becoming
29751 unresponsive when it runs out of memory.
29753 @deffn {Scheme Variable} earlyoom-service-type
29754 The service type for running @command{earlyoom}, the Early OOM daemon.
29755 Its value must be a @code{earlyoom-configuration} object, described
29756 below. The service can be instantiated in its default configuration
29760 (service earlyoom-service-type)
29764 @deftp {Data Type} earlyoom-configuration
29765 This is the configuration record for the @code{earlyoom-service-type}.
29768 @item @code{earlyoom} (default: @var{earlyoom})
29769 The Earlyoom package to use.
29771 @item @code{minimum-available-memory} (default: @code{10})
29772 The threshold for the minimum @emph{available} memory, in percentages.
29774 @item @code{minimum-free-swap} (default: @code{10})
29775 The threshold for the minimum free swap memory, in percentages.
29777 @item @code{prefer-regexp} (default: @code{#f})
29778 A regular expression (as a string) to match the names of the processes
29779 that should be preferably killed.
29781 @item @code{avoid-regexp} (default: @code{#f})
29782 A regular expression (as a string) to match the names of the processes
29783 that should @emph{not} be killed.
29785 @item @code{memory-report-interval} (default: @code{0})
29786 The interval in seconds at which a memory report is printed. It is
29787 disabled by default.
29789 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
29790 A boolean indicating whether the positive adjustments set in
29791 @file{/proc/*/oom_score_adj} should be ignored.
29793 @item @code{show-debug-messages?} (default: @code{#f})
29794 A boolean indicating whether debug messages should be printed. The logs
29795 are saved at @file{/var/log/earlyoom.log}.
29797 @item @code{send-notification-command} (default: @code{#f})
29798 This can be used to provide a custom command used for sending
29804 @cindex kernel module loader
29805 @subsubheading Kernel Module Loader Service
29807 The kernel module loader service allows one to load loadable kernel
29808 modules at boot. This is especially useful for modules that don't
29809 autoload and need to be manually loaded, as it's the case with
29812 @deffn {Scheme Variable} kernel-module-loader-service-type
29813 The service type for loading loadable kernel modules at boot with
29814 @command{modprobe}. Its value must be a list of strings representing
29815 module names. For example loading the drivers provided by
29816 @code{ddcci-driver-linux}, in debugging mode by passing some module
29817 parameters, can be done as follow:
29820 (use-modules (gnu) (gnu services))
29821 (use-package-modules linux)
29822 (use-service-modules linux)
29824 (define ddcci-config
29825 (plain-file "ddcci.conf"
29826 "options ddcci dyndbg delay=120"))
29830 (services (cons* (service kernel-module-loader-service-type
29831 '("ddcci" "ddcci_backlight"))
29832 (simple-service 'ddcci-config etc-service-type
29833 (list `("modprobe.d/ddcci.conf"
29836 (kernel-loadable-modules (list ddcci-driver-linux)))
29841 @cindex compressed swap
29842 @cindex Compressed RAM-based block devices
29843 @subsubheading Zram Device Service
29845 The Zram device service provides a compressed swap device in system
29846 memory. The Linux Kernel documentation has more information about
29847 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
29850 @deffn {Scheme Variable} zram-device-service-type
29851 This service creates the zram block device, formats it as swap and
29852 enables it as a swap device. The service's value is a
29853 @code{zram-device-configuration} record.
29855 @deftp {Data Type} zram-device-configuration
29856 This is the data type representing the configuration for the zram-device
29860 @item @code{size} (default @code{"1G"})
29861 This is the amount of space you wish to provide for the zram device. It
29862 accepts a string and can be a number of bytes or use a suffix, eg.:
29863 @code{"512M"} or @code{1024000}.
29864 @item @code{compression-algorithm} (default @code{'lzo})
29865 This is the compression algorithm you wish to use. It is difficult to
29866 list all the possible compression options, but common ones supported by
29867 Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
29868 @item @code{memory-limit} (default @code{0})
29869 This is the maximum amount of memory which the zram device can use.
29870 Setting it to '0' disables the limit. While it is generally expected
29871 that compression will be 2:1, it is possible that uncompressable data
29872 can be written to swap and this is a method to limit how much memory can
29873 be used. It accepts a string and can be a number of bytes or use a
29874 suffix, eg.: @code{"2G"}.
29875 @item @code{priority} (default @code{-1})
29876 This is the priority of the swap device created from the zram device.
29877 @code{swapon} accepts values between -1 and 32767, with higher values
29878 indicating higher priority. Higher priority swap will generally be used
29885 @node Hurd Services
29886 @subsection Hurd Services
29888 @defvr {Scheme Variable} hurd-console-service-type
29889 This service starts the fancy @code{VGA} console client on the Hurd.
29891 The service's value is a @code{hurd-console-configuration} record.
29894 @deftp {Data Type} hurd-console-configuration
29895 This is the data type representing the configuration for the
29896 hurd-console-service.
29899 @item @code{hurd} (default: @var{hurd})
29900 The Hurd package to use.
29904 @defvr {Scheme Variable} hurd-getty-service-type
29905 This service starts a tty using the Hurd @code{getty} program.
29907 The service's value is a @code{hurd-getty-configuration} record.
29910 @deftp {Data Type} hurd-getty-configuration
29911 This is the data type representing the configuration for the
29912 hurd-getty-service.
29915 @item @code{hurd} (default: @var{hurd})
29916 The Hurd package to use.
29919 The name of the console this Getty runs on---e.g., @code{"tty1"}.
29921 @item @code{baud-rate} (default: @code{38400})
29922 An integer specifying the baud rate of the tty.
29927 @node Miscellaneous Services
29928 @subsection Miscellaneous Services
29930 @cindex fingerprint
29931 @subsubheading Fingerprint Service
29933 The @code{(gnu services authentication)} module provides a DBus service to
29934 read and identify fingerprints via a fingerprint sensor.
29936 @defvr {Scheme Variable} fprintd-service-type
29937 The service type for @command{fprintd}, which provides the fingerprint
29938 reading capability.
29941 (service fprintd-service-type)
29946 @subsubheading System Control Service
29948 The @code{(gnu services sysctl)} provides a service to configure kernel
29949 parameters at boot.
29951 @defvr {Scheme Variable} sysctl-service-type
29952 The service type for @command{sysctl}, which modifies kernel parameters
29953 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
29957 (service sysctl-service-type
29958 (sysctl-configuration
29959 (settings '(("net.ipv4.ip_forward" . "1")))))
29963 @deftp {Data Type} sysctl-configuration
29964 The data type representing the configuration of @command{sysctl}.
29967 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
29968 The @command{sysctl} executable to use.
29970 @item @code{settings} (default: @code{'()})
29971 An association list specifies kernel parameters and their values.
29976 @subsubheading PC/SC Smart Card Daemon Service
29978 The @code{(gnu services security-token)} module provides the following service
29979 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
29980 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
29981 manager that coordinates communications with smart card readers, smart cards
29982 and cryptographic tokens that are connected to the system.
29984 @defvr {Scheme Variable} pcscd-service-type
29985 Service type for the @command{pcscd} service. Its value must be a
29986 @code{pcscd-configuration} object. To run pcscd in the default
29987 configuration, instantiate it as:
29990 (service pcscd-service-type)
29994 @deftp {Data Type} pcscd-configuration
29995 The data type representing the configuration of @command{pcscd}.
29998 @item @code{pcsc-lite} (default: @code{pcsc-lite})
29999 The pcsc-lite package that provides pcscd.
30000 @item @code{usb-drivers} (default: @code{(list ccid)})
30001 List of packages that provide USB drivers to pcscd. Drivers are expected to be
30002 under @file{pcsc/drivers} in the store directory of the package.
30007 @subsubheading Lirc Service
30009 The @code{(gnu services lirc)} module provides the following service.
30011 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
30012 [#:device #f] [#:driver #f] [#:config-file #f] @
30013 [#:extra-options '()]
30014 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
30015 decodes infrared signals from remote controls.
30017 Optionally, @var{device}, @var{driver} and @var{config-file}
30018 (configuration file name) may be specified. See @command{lircd} manual
30021 Finally, @var{extra-options} is a list of additional command-line options
30022 passed to @command{lircd}.
30026 @subsubheading Spice Service
30028 The @code{(gnu services spice)} module provides the following service.
30030 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
30031 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
30032 that enables sharing the clipboard with a vm and setting the guest display
30033 resolution when the graphical console window resizes.
30036 @cindex inputattach
30037 @subsubheading inputattach Service
30039 @cindex tablet input, for Xorg
30040 @cindex touchscreen input, for Xorg
30041 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
30042 use input devices such as Wacom tablets, touchscreens, or joysticks with the
30043 Xorg display server.
30045 @deffn {Scheme Variable} inputattach-service-type
30046 Type of a service that runs @command{inputattach} on a device and
30047 dispatches events from it.
30050 @deftp {Data Type} inputattach-configuration
30052 @item @code{device-type} (default: @code{"wacom"})
30053 The type of device to connect to. Run @command{inputattach --help}, from the
30054 @code{inputattach} package, to see the list of supported device types.
30056 @item @code{device} (default: @code{"/dev/ttyS0"})
30057 The device file to connect to the device.
30059 @item @code{baud-rate} (default: @code{#f})
30060 Baud rate to use for the serial connection.
30061 Should be a number or @code{#f}.
30063 @item @code{log-file} (default: @code{#f})
30064 If true, this must be the name of a file to log messages to.
30068 @subsubheading Dictionary Service
30070 The @code{(gnu services dict)} module provides the following service:
30072 @defvr {Scheme Variable} dicod-service-type
30073 This is the type of the service that runs the @command{dicod} daemon, an
30074 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
30077 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
30078 Return a service that runs the @command{dicod} daemon, an implementation
30079 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
30081 The optional @var{config} argument specifies the configuration for
30082 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
30083 default it serves the GNU Collaborative International Dictionary of English.
30085 You can add @command{open localhost} to your @file{~/.dico} file to make
30086 @code{localhost} the default server for @command{dico} client
30087 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
30090 @deftp {Data Type} dicod-configuration
30091 Data type representing the configuration of dicod.
30094 @item @code{dico} (default: @var{dico})
30095 Package object of the GNU Dico dictionary server.
30097 @item @code{interfaces} (default: @var{'("localhost")})
30098 This is the list of IP addresses and ports and possibly socket file
30099 names to listen to (@pxref{Server Settings, @code{listen} directive,,
30100 dico, GNU Dico Manual}).
30102 @item @code{handlers} (default: @var{'()})
30103 List of @code{<dicod-handler>} objects denoting handlers (module instances).
30105 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
30106 List of @code{<dicod-database>} objects denoting dictionaries to be served.
30110 @deftp {Data Type} dicod-handler
30111 Data type representing a dictionary handler (module instance).
30115 Name of the handler (module instance).
30117 @item @code{module} (default: @var{#f})
30118 Name of the dicod module of the handler (instance). If it is @code{#f},
30119 the module has the same name as the handler.
30120 (@pxref{Modules,,, dico, GNU Dico Manual}).
30122 @item @code{options}
30123 List of strings or gexps representing the arguments for the module handler
30127 @deftp {Data Type} dicod-database
30128 Data type representing a dictionary database.
30132 Name of the database, will be used in DICT commands.
30134 @item @code{handler}
30135 Name of the dicod handler (module instance) used by this database
30136 (@pxref{Handlers,,, dico, GNU Dico Manual}).
30138 @item @code{complex?} (default: @var{#f})
30139 Whether the database configuration complex. The complex configuration
30140 will need a corresponding @code{<dicod-handler>} object, otherwise not.
30142 @item @code{options}
30143 List of strings or gexps representing the arguments for the database
30144 (@pxref{Databases,,, dico, GNU Dico Manual}).
30148 @defvr {Scheme Variable} %dicod-database:gcide
30149 A @code{<dicod-database>} object serving the GNU Collaborative International
30150 Dictionary of English using the @code{gcide} package.
30153 The following is an example @code{dicod-service} configuration.
30156 (dicod-service #:config
30157 (dicod-configuration
30158 (handlers (list (dicod-handler
30162 (list #~(string-append "dbdir=" #$wordnet))))))
30163 (databases (list (dicod-database
30166 (handler "wordnet")
30167 (options '("database=wn")))
30168 %dicod-database:gcide))))
30172 @subsubheading Docker Service
30174 The @code{(gnu services docker)} module provides the following services.
30176 @defvr {Scheme Variable} docker-service-type
30178 This is the type of the service that runs @url{https://www.docker.com,Docker},
30179 a daemon that can execute application bundles (sometimes referred to as
30180 ``containers'') in isolated environments.
30184 @deftp {Data Type} docker-configuration
30185 This is the data type representing the configuration of Docker and Containerd.
30189 @item @code{package} (default: @code{docker})
30190 The Docker daemon package to use.
30192 @item @code{package} (default: @code{docker-cli})
30193 The Docker client package to use.
30195 @item @code{containerd} (default: @var{containerd})
30196 The Containerd package to use.
30198 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
30199 The Docker user-land networking proxy package to use.
30201 @item @code{enable-proxy?} (default @code{#t})
30202 Enable or disable the use of the Docker user-land networking proxy.
30204 @item @code{debug?} (default @code{#f})
30205 Enable or disable debug output.
30207 @item @code{enable-iptables?} (default @code{#t})
30208 Enable or disable the addition of iptables rules.
30213 @cindex Singularity, container service
30214 @defvr {Scheme Variable} singularity-service-type
30215 This is the type of the service that allows you to run
30216 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
30217 create and run application bundles (aka. ``containers''). The value for this
30218 service is the Singularity package to use.
30220 The service does not install a daemon; instead, it installs helper programs as
30221 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
30222 @command{singularity run} and similar commands.
30226 @subsubheading Auditd Service
30228 The @code{(gnu services auditd)} module provides the following service.
30230 @defvr {Scheme Variable} auditd-service-type
30232 This is the type of the service that runs
30233 @url{https://people.redhat.com/sgrubb/audit/,auditd},
30234 a daemon that tracks security-relevant information on your system.
30236 Examples of things that can be tracked:
30246 Failed login attempts
30253 @command{auditctl} from the @code{audit} package can be used in order
30254 to add or remove events to be tracked (until the next reboot).
30255 In order to permanently track events, put the command line arguments
30256 of auditctl into a file called @code{audit.rules} in the configuration
30257 directory (see below).
30258 @command{aureport} from the @code{audit} package can be used in order
30259 to view a report of all recorded events.
30260 The audit daemon by default logs into the file
30261 @file{/var/log/audit.log}.
30265 @deftp {Data Type} auditd-configuration
30266 This is the data type representing the configuration of auditd.
30270 @item @code{audit} (default: @code{audit})
30271 The audit package to use.
30273 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
30274 The directory containing the configuration file for the audit package, which
30275 must be named @code{auditd.conf}, and optionally some audit rules to
30276 instantiate on startup.
30282 @subsubheading R-Shiny service
30284 The @code{(gnu services science)} module provides the following service.
30286 @defvr {Scheme Variable} rshiny-service-type
30288 This is a type of service which is used to run a webapp created with
30289 @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
30290 variable and runs the provided script to call @code{runApp}.
30292 @deftp {Data Type} rshiny-configuration
30293 This is the data type representing the configuration of rshiny.
30297 @item @code{package} (default: @code{r-shiny})
30298 The package to use.
30300 @item @code{binary} (defaunlt @code{"rshiny"})
30301 The name of the binary or shell script located at @code{package/bin/} to
30302 run when the service is run.
30304 The common way to create this file is as follows:
30308 (let* ((out (assoc-ref %outputs "out"))
30309 (targetdir (string-append out "/share/" ,name))
30310 (app (string-append out "/bin/" ,name))
30311 (Rbin (string-append (assoc-ref %build-inputs "r-min")
30314 (mkdir-p (string-append out "/bin"))
30315 (call-with-output-file app
30321 runApp(launch.browser=0, port=4202)~%\n"
30330 @subsubheading Nix service
30332 The @code{(gnu services nix)} module provides the following service.
30334 @defvr {Scheme Variable} nix-service-type
30336 This is the type of the service that runs build daemon of the
30337 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
30341 (use-modules (gnu))
30342 (use-service-modules nix)
30343 (use-package-modules package-management)
30347 (packages (append (list nix)
30350 (services (append (list (service nix-service-type))
30354 After @command{guix system reconfigure} configure Nix for your user:
30357 @item Add a Nix channel and update it. See
30358 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
30360 @item Create a symlink to your profile and activate Nix profile:
30364 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
30365 $ source /run/current-system/profile/etc/profile.d/nix.sh
30370 @deftp {Data Type} nix-configuration
30371 This data type represents the configuration of the Nix daemon.
30374 @item @code{nix} (default: @code{nix})
30375 The Nix package to use.
30377 @item @code{sandbox} (default: @code{#t})
30378 Specifies whether builds are sandboxed by default.
30380 @item @code{build-sandbox-items} (default: @code{'()})
30381 This is a list of strings or objects appended to the
30382 @code{build-sandbox-items} field of the configuration file.
30384 @item @code{extra-config} (default: @code{'()})
30385 This is a list of strings or objects appended to the configuration file.
30386 It is used to pass extra text to be added verbatim to the configuration
30389 @item @code{extra-options} (default: @code{'()})
30390 Extra command line options for @code{nix-service-type}.
30394 @node Setuid Programs
30395 @section Setuid Programs
30397 @cindex setuid programs
30398 Some programs need to run with ``root'' privileges, even when they are
30399 launched by unprivileged users. A notorious example is the
30400 @command{passwd} program, which users can run to change their
30401 password, and which needs to access the @file{/etc/passwd} and
30402 @file{/etc/shadow} files---something normally restricted to root, for
30403 obvious security reasons. To address that, these executables are
30404 @dfn{setuid-root}, meaning that they always run with root privileges
30405 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
30406 for more info about the setuid mechanism).
30408 The store itself @emph{cannot} contain setuid programs: that would be a
30409 security issue since any user on the system can write derivations that
30410 populate the store (@pxref{The Store}). Thus, a different mechanism is
30411 used: instead of changing the setuid bit directly on files that are in
30412 the store, we let the system administrator @emph{declare} which programs
30413 should be setuid root.
30415 The @code{setuid-programs} field of an @code{operating-system}
30416 declaration contains a list of G-expressions denoting the names of
30417 programs to be setuid-root (@pxref{Using the Configuration System}).
30418 For instance, the @command{passwd} program, which is part of the Shadow
30419 package, can be designated by this G-expression (@pxref{G-Expressions}):
30422 #~(string-append #$shadow "/bin/passwd")
30425 A default set of setuid programs is defined by the
30426 @code{%setuid-programs} variable of the @code{(gnu system)} module.
30428 @defvr {Scheme Variable} %setuid-programs
30429 A list of G-expressions denoting common programs that are setuid-root.
30431 The list includes commands such as @command{passwd}, @command{ping},
30432 @command{su}, and @command{sudo}.
30435 Under the hood, the actual setuid programs are created in the
30436 @file{/run/setuid-programs} directory at system activation time. The
30437 files in this directory refer to the ``real'' binaries, which are in the
30440 @node X.509 Certificates
30441 @section X.509 Certificates
30443 @cindex HTTPS, certificates
30444 @cindex X.509 certificates
30446 Web servers available over HTTPS (that is, HTTP over the transport-layer
30447 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
30448 that the client can then use to @emph{authenticate} the server. To do
30449 that, clients verify that the server's certificate is signed by a
30450 so-called @dfn{certificate authority} (CA). But to verify the CA's
30451 signature, clients must have first acquired the CA's certificate.
30453 Web browsers such as GNU@tie{}IceCat include their own set of CA
30454 certificates, such that they are able to verify CA signatures
30457 However, most other programs that can talk HTTPS---@command{wget},
30458 @command{git}, @command{w3m}, etc.---need to be told where CA
30459 certificates can be found.
30461 @cindex @code{nss-certs}
30462 In Guix, this is done by adding a package that provides certificates
30463 to the @code{packages} field of the @code{operating-system} declaration
30464 (@pxref{operating-system Reference}). Guix includes one such package,
30465 @code{nss-certs}, which is a set of CA certificates provided as part of
30466 Mozilla's Network Security Services.
30468 Note that it is @emph{not} part of @code{%base-packages}, so you need to
30469 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
30470 most applications and libraries look for certificates by default, points
30471 to the certificates installed globally.
30473 Unprivileged users, including users of Guix on a foreign distro,
30474 can also install their own certificate package in
30475 their profile. A number of environment variables need to be defined so
30476 that applications and libraries know where to find them. Namely, the
30477 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
30478 variables. Some applications add their own environment variables; for
30479 instance, the Git version control system honors the certificate bundle
30480 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
30481 would typically run something like:
30484 guix install nss-certs
30485 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
30486 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
30487 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
30490 As another example, R requires the @env{CURL_CA_BUNDLE} environment
30491 variable to point to a certificate bundle, so you would have to run
30492 something like this:
30495 guix install nss-certs
30496 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
30499 For other applications you may want to look up the required environment
30500 variable in the relevant documentation.
30503 @node Name Service Switch
30504 @section Name Service Switch
30506 @cindex name service switch
30508 The @code{(gnu system nss)} module provides bindings to the
30509 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
30510 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
30511 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
30512 extended with new ``name'' lookup methods for system databases, which
30513 includes host names, service names, user accounts, and more (@pxref{Name
30514 Service Switch, System Databases and Name Service Switch,, libc, The GNU
30515 C Library Reference Manual}).
30517 The NSS configuration specifies, for each system database, which lookup
30518 method is to be used, and how the various methods are chained
30519 together---for instance, under which circumstances NSS should try the
30520 next method in the list. The NSS configuration is given in the
30521 @code{name-service-switch} field of @code{operating-system} declarations
30522 (@pxref{operating-system Reference, @code{name-service-switch}}).
30525 @cindex .local, host name lookup
30526 As an example, the declaration below configures the NSS to use the
30527 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
30528 back-end}, which supports host name lookups over multicast DNS (mDNS)
30529 for host names ending in @code{.local}:
30532 (name-service-switch
30533 (hosts (list %files ;first, check /etc/hosts
30535 ;; If the above did not succeed, try
30536 ;; with 'mdns_minimal'.
30538 (name "mdns_minimal")
30540 ;; 'mdns_minimal' is authoritative for
30541 ;; '.local'. When it returns "not found",
30542 ;; no need to try the next methods.
30543 (reaction (lookup-specification
30544 (not-found => return))))
30546 ;; Then fall back to DNS.
30550 ;; Finally, try with the "full" 'mdns'.
30555 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
30556 contains this configuration, so you will not have to type it if all you
30557 want is to have @code{.local} host lookup working.
30559 Note that, in this case, in addition to setting the
30560 @code{name-service-switch} of the @code{operating-system} declaration,
30561 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
30562 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
30563 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
30564 to the name service cache daemon (@pxref{Base Services,
30565 @code{nscd-service}}).
30567 For convenience, the following variables provide typical NSS
30570 @defvr {Scheme Variable} %default-nss
30571 This is the default name service switch configuration, a
30572 @code{name-service-switch} object.
30575 @defvr {Scheme Variable} %mdns-host-lookup-nss
30576 This is the name service switch configuration with support for host name
30577 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
30580 The reference for name service switch configuration is given below. It
30581 is a direct mapping of the configuration file format of the C library , so
30582 please refer to the C library manual for more information (@pxref{NSS
30583 Configuration File,,, libc, The GNU C Library Reference Manual}).
30584 Compared to the configuration file format of libc NSS, it has the advantage
30585 not only of adding this warm parenthetic feel that we like, but also
30586 static checks: you will know about syntax errors and typos as soon as you
30587 run @command{guix system}.
30589 @deftp {Data Type} name-service-switch
30591 This is the data type representation the configuration of libc's name
30592 service switch (NSS). Each field below represents one of the supported
30609 The system databases handled by the NSS. Each of these fields must be a
30610 list of @code{<name-service>} objects (see below).
30614 @deftp {Data Type} name-service
30616 This is the data type representing an actual name service and the
30617 associated lookup action.
30621 A string denoting the name service (@pxref{Services in the NSS
30622 configuration,,, libc, The GNU C Library Reference Manual}).
30624 Note that name services listed here must be visible to nscd. This is
30625 achieved by passing the @code{#:name-services} argument to
30626 @code{nscd-service} the list of packages providing the needed name
30627 services (@pxref{Base Services, @code{nscd-service}}).
30630 An action specified using the @code{lookup-specification} macro
30631 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
30632 Reference Manual}). For example:
30635 (lookup-specification (unavailable => continue)
30636 (success => return))
30641 @node Initial RAM Disk
30642 @section Initial RAM Disk
30645 @cindex initial RAM disk
30646 For bootstrapping purposes, the Linux-Libre kernel is passed an
30647 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
30648 root file system as well as an initialization script. The latter is
30649 responsible for mounting the real root file system, and for loading any
30650 kernel modules that may be needed to achieve that.
30652 The @code{initrd-modules} field of an @code{operating-system}
30653 declaration allows you to specify Linux-libre kernel modules that must
30654 be available in the initrd. In particular, this is where you would list
30655 modules needed to actually drive the hard disk where your root partition
30656 is---although the default value of @code{initrd-modules} should cover
30657 most use cases. For example, assuming you need the @code{megaraid_sas}
30658 module in addition to the default modules to be able to access your root
30659 file system, you would write:
30664 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
30667 @defvr {Scheme Variable} %base-initrd-modules
30668 This is the list of kernel modules included in the initrd by default.
30671 Furthermore, if you need lower-level customization, the @code{initrd}
30672 field of an @code{operating-system} declaration allows
30673 you to specify which initrd you would like to use. The @code{(gnu
30674 system linux-initrd)} module provides three ways to build an initrd: the
30675 high-level @code{base-initrd} procedure and the low-level
30676 @code{raw-initrd} and @code{expression->initrd} procedures.
30678 The @code{base-initrd} procedure is intended to cover most common uses.
30679 For example, if you want to add a bunch of kernel modules to be loaded
30680 at boot time, you can define the @code{initrd} field of the operating
30681 system declaration like this:
30684 (initrd (lambda (file-systems . rest)
30685 ;; Create a standard initrd but set up networking
30686 ;; with the parameters QEMU expects by default.
30687 (apply base-initrd file-systems
30688 #:qemu-networking? #t
30692 The @code{base-initrd} procedure also handles common use cases that
30693 involves using the system as a QEMU guest, or as a ``live'' system with
30694 volatile root file system.
30696 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
30697 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
30698 such as trying to guess which kernel modules and packages should be included
30699 to the initrd. An example use of @code{raw-initrd} is when a user has
30700 a custom Linux kernel configuration and default kernel modules included by
30701 @code{base-initrd} are not available.
30703 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
30704 honors several options passed on the Linux kernel command line
30705 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
30706 @code{-append} option of QEMU), notably:
30709 @item --load=@var{boot}
30710 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
30711 program, once it has mounted the root file system.
30713 Guix uses this option to yield control to a boot program that runs the
30714 service activation programs and then spawns the GNU@tie{}Shepherd, the
30715 initialization system.
30717 @item --root=@var{root}
30718 Mount @var{root} as the root file system. @var{root} can be a device
30719 name like @code{/dev/sda1}, a file system label, or a file system UUID.
30720 When unspecified, the device name from the root file system of the
30721 operating system declaration is used.
30723 @item --system=@var{system}
30724 Have @file{/run/booted-system} and @file{/run/current-system} point to
30727 @item modprobe.blacklist=@var{modules}@dots{}
30728 @cindex module, black-listing
30729 @cindex black list, of kernel modules
30730 Instruct the initial RAM disk as well as the @command{modprobe} command
30731 (from the kmod package) to refuse to load @var{modules}. @var{modules}
30732 must be a comma-separated list of module names---e.g.,
30733 @code{usbkbd,9pnet}.
30736 Start a read-eval-print loop (REPL) from the initial RAM disk before it
30737 tries to load kernel modules and to mount the root file system. Our
30738 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
30739 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
30740 Manual}, for more information on Guile's REPL.
30744 Now that you know all the features that initial RAM disks produced by
30745 @code{base-initrd} and @code{raw-initrd} provide,
30746 here is how to use it and customize it further.
30749 @cindex initial RAM disk
30750 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
30751 [#:linux-modules '()] [#:mapped-devices '()] @
30752 [#:keyboard-layout #f] @
30753 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
30754 Return a derivation that builds a raw initrd. @var{file-systems} is
30755 a list of file systems to be mounted by the initrd, possibly in addition to
30756 the root file system specified on the kernel command line via @option{--root}.
30757 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
30758 @var{mapped-devices} is a list of device mappings to realize before
30759 @var{file-systems} are mounted (@pxref{Mapped Devices}).
30760 @var{helper-packages} is a list of packages to be copied in the initrd.
30762 include @code{e2fsck/static} or other packages needed by the initrd to check
30763 the root file system.
30765 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
30766 the desired console keyboard layout. This is done before @var{mapped-devices}
30767 are set up and before @var{file-systems} are mounted such that, should the
30768 user need to enter a passphrase or use the REPL, this happens using the
30769 intended keyboard layout.
30771 When @var{qemu-networking?} is true, set up networking with the standard QEMU
30772 parameters. When @var{virtio?} is true, load additional modules so that the
30773 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
30775 When @var{volatile-root?} is true, the root file system is writable but any changes
30779 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
30780 [#:mapped-devices '()] [#:keyboard-layout #f] @
30781 [#:qemu-networking? #f] [#:volatile-root? #f] @
30782 [#:linux-modules '()]
30783 Return as a file-like object a generic initrd, with kernel
30784 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
30785 mounted by the initrd, possibly in addition to the root file system specified
30786 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
30787 mappings to realize before @var{file-systems} are mounted.
30789 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
30790 the desired console keyboard layout. This is done before @var{mapped-devices}
30791 are set up and before @var{file-systems} are mounted such that, should the
30792 user need to enter a passphrase or use the REPL, this happens using the
30793 intended keyboard layout.
30795 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
30797 The initrd is automatically populated with all the kernel modules necessary
30798 for @var{file-systems} and for the given options. Additional kernel
30799 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
30800 loaded at boot time in the order in which they appear.
30803 Needless to say, the initrds we produce and use embed a
30804 statically-linked Guile, and the initialization program is a Guile
30805 program. That gives a lot of flexibility. The
30806 @code{expression->initrd} procedure builds such an initrd, given the
30807 program to run in that initrd.
30809 @deffn {Scheme Procedure} expression->initrd @var{exp} @
30810 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
30811 Return as a file-like object a Linux initrd (a gzipped cpio archive)
30812 containing @var{guile} and that evaluates @var{exp}, a G-expression,
30813 upon booting. All the derivations referenced by @var{exp} are
30814 automatically copied to the initrd.
30817 @node Bootloader Configuration
30818 @section Bootloader Configuration
30821 @cindex boot loader
30823 The operating system supports multiple bootloaders. The bootloader is
30824 configured using @code{bootloader-configuration} declaration. All the
30825 fields of this structure are bootloader agnostic except for one field,
30826 @code{bootloader} that indicates the bootloader to be configured and
30829 Some of the bootloaders do not honor every field of
30830 @code{bootloader-configuration}. For instance, the extlinux
30831 bootloader does not support themes and thus ignores the @code{theme}
30834 @deftp {Data Type} bootloader-configuration
30835 The type of a bootloader configuration declaration.
30839 @item @code{bootloader}
30840 @cindex EFI, bootloader
30841 @cindex UEFI, bootloader
30842 @cindex BIOS, bootloader
30843 The bootloader to use, as a @code{bootloader} object. For now
30844 @code{grub-bootloader}, @code{grub-efi-bootloader},
30845 @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
30846 @code{u-boot-bootloader} are supported.
30848 @cindex ARM, bootloaders
30849 @cindex AArch64, bootloaders
30850 Available bootloaders are described in @code{(gnu bootloader @dots{})}
30851 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
30852 of bootloaders for a wide range of ARM and AArch64 systems, using the
30853 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
30855 @vindex grub-efi-bootloader
30856 @code{grub-efi-bootloader} allows to boot on modern systems using the
30857 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
30858 use if the installation image contains a @file{/sys/firmware/efi} directory
30859 when you boot it on your system.
30861 @vindex grub-bootloader
30862 @code{grub-bootloader} allows you to boot in particular Intel-based machines
30863 in ``legacy'' BIOS mode.
30865 @vindex grub-efi-netboot-bootloader
30866 @code{grub-efi-netboot-bootloader} allows you to boot your system over network
30867 through TFTP. In combination with an NFS root file system this allows you to
30868 build a diskless Guix system.
30870 The installation of the @code{grub-efi-netboot-bootloader} generates the content
30871 of the TFTP root directory at @code{target}
30872 (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
30873 You may want to mount your TFTP server directory onto @code{target} to move the
30874 required files to the TFTP server automatically.
30876 If you plan to use an NFS root file system as well (actually if you mount the
30877 store from an NFS share), then the TFTP server needs to serve the file
30878 @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
30879 image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
30880 initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
30881 files from the store will be accessed by GRUB through TFTP with their normal
30882 store path, for example as
30883 @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
30885 Two symlinks are created to make this possible. The first symlink is
30886 @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
30887 @file{../../../boot/grub/grub.cfg},
30888 where @code{target} may be @file{/boot}. In this case the link is not leaving
30889 the served TFTP root directory, but otherwise it does. The second link is
30890 @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
30891 is leaving the served TFTP root directory.
30893 The assumption behind all this is that you have an NFS server exporting the root
30894 file system for your Guix system, and additionally a TFTP server exporting your
30895 @code{target} directory—usually @file{/boot}—from that same root file system for
30896 your Guix system. In this constellation the symlinks will work.
30898 For other constellations you will have to program your own bootloader installer,
30899 which then takes care to make necessary files from the store accessible through
30900 TFTP, for example by copying them into the TFTP root directory at @code{target}.
30902 It is important to note that symlinks pointing outside the TFTP root directory
30903 may need to be allowed in the configuration of your TFTP server. Further the
30904 store link exposes the whole store through TFTP. Both points need to be
30905 considered carefully for security aspects.
30907 Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
30908 NFS servers, you also need a properly configured DHCP server to make the booting
30909 over netboot possible. For all this we can currently only recommend you to look
30910 for instructions about @acronym{PXE, Preboot eXecution Environment}.
30912 @item @code{target}
30913 This is a string denoting the target onto which to install the
30916 The interpretation depends on the bootloader in question. For
30917 @code{grub-bootloader}, for example, it should be a device name understood by
30918 the bootloader @command{installer} command, such as @code{/dev/sda} or
30919 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
30920 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
30921 system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
30922 @code{target} should be the mount point corresponding to the TFTP root
30923 directory of your TFTP server.
30925 @item @code{menu-entries} (default: @code{()})
30926 A possibly empty list of @code{menu-entry} objects (see below), denoting
30927 entries to appear in the bootloader menu, in addition to the current
30928 system entry and the entry pointing to previous system generations.
30930 @item @code{default-entry} (default: @code{0})
30931 The index of the default boot menu entry. Index 0 is for the entry of the
30934 @item @code{timeout} (default: @code{5})
30935 The number of seconds to wait for keyboard input before booting. Set to
30936 0 to boot immediately, and to -1 to wait indefinitely.
30938 @cindex keyboard layout, for the bootloader
30939 @item @code{keyboard-layout} (default: @code{#f})
30940 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
30941 layout, usually US@tie{}English (``qwerty'').
30943 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
30947 This option is currently ignored by bootloaders other than @code{grub} and
30951 @item @code{theme} (default: @var{#f})
30952 The bootloader theme object describing the theme to use. If no theme
30953 is provided, some bootloaders might use a default theme, that's true
30956 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
30957 The output terminals used for the bootloader boot menu, as a list of
30958 symbols. GRUB accepts the values: @code{console}, @code{serial},
30959 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
30960 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
30961 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
30962 configuration,,, grub,GNU GRUB manual}).
30964 @item @code{terminal-inputs} (default: @code{'()})
30965 The input terminals used for the bootloader boot menu, as a list of
30966 symbols. For GRUB, the default is the native platform terminal as
30967 determined at run-time. GRUB accepts the values: @code{console},
30968 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
30969 @code{usb_keyboard}. This field corresponds to the GRUB variable
30970 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
30973 @item @code{serial-unit} (default: @code{#f})
30974 The serial unit used by the bootloader, as an integer from 0 to 3.
30975 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
30976 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
30978 @item @code{serial-speed} (default: @code{#f})
30979 The speed of the serial interface, as an integer. For GRUB, the
30980 default value is chosen at run-time; currently GRUB chooses
30981 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
30988 Should you want to list additional boot menu entries @i{via} the
30989 @code{menu-entries} field above, you will need to create them with the
30990 @code{menu-entry} form. For example, imagine you want to be able to
30991 boot another distro (hard to imagine!), you can define a menu entry
30996 (label "The Other Distro")
30997 (linux "/boot/old/vmlinux-2.6.32")
30998 (linux-arguments '("root=/dev/sda2"))
30999 (initrd "/boot/old/initrd"))
31004 @deftp {Data Type} menu-entry
31005 The type of an entry in the bootloader menu.
31010 The label to show in the menu---e.g., @code{"GNU"}.
31012 @item @code{linux} (default: @code{#f})
31013 The Linux kernel image to boot, for example:
31016 (file-append linux-libre "/bzImage")
31019 For GRUB, it is also possible to specify a device explicitly in the
31020 file path using GRUB's device naming convention (@pxref{Naming
31021 convention,,, grub, GNU GRUB manual}), for example:
31024 "(hd0,msdos1)/boot/vmlinuz"
31027 If the device is specified explicitly as above, then the @code{device}
31028 field is ignored entirely.
31030 @item @code{linux-arguments} (default: @code{()})
31031 The list of extra Linux kernel command-line arguments---e.g.,
31032 @code{("console=ttyS0")}.
31034 @item @code{initrd} (default: @code{#f})
31035 A G-Expression or string denoting the file name of the initial RAM disk
31036 to use (@pxref{G-Expressions}).
31038 @item @code{device} (default: @code{#f})
31039 The device where the kernel and initrd are to be found---i.e., for GRUB,
31040 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
31042 This may be a file system label (a string), a file system UUID (a
31043 bytevector, @pxref{File Systems}), or @code{#f}, in which case
31044 the bootloader will search the device containing the file specified by
31045 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
31046 must @emph{not} be an OS device name such as @file{/dev/sda1}.
31048 @item @code{multiboot-kernel} (default: @code{#f})
31049 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
31050 manual}). When this field is set, a Multiboot menu-entry is generated.
31054 (file-append mach "/boot/gnumach")
31057 @item @code{multiboot-arguments} (default: @code{()})
31058 The list of extra command-line arguments for the multiboot-kernel.
31060 @item @code{multiboot-modules} (default: @code{()})
31061 The list of commands for loading Multiboot modules. For example:
31064 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
31066 (list (file-append libc "/lib/ld.so.1") "exec"
31076 @c FIXME: Write documentation once it's stable.
31077 For now only GRUB has theme support. GRUB themes are created using
31078 the @code{grub-theme} form, which is not fully documented yet.
31080 @deftp {Data Type} grub-theme
31081 Data type representing the configuration of the GRUB theme.
31084 @item @code{gfxmode} (default: @code{'("auto")})
31085 The GRUB @code{gfxmode} to set (a list of screen resolution strings,
31086 @pxref{gfxmode,,, grub, GNU GRUB manual}).
31090 @deffn {Scheme Procedure} grub-theme
31091 Return the default GRUB theme used by the operating system if no
31092 @code{theme} field is specified in @code{bootloader-configuration}
31095 It comes with a fancy background image displaying the GNU and Guix
31099 For example, to override the default resolution, you may use something
31104 (bootloader-configuration
31107 (inherit (grub-theme))
31108 (gfxmode '("1024x786x32" "auto"))))))
31111 @node Invoking guix system
31112 @section Invoking @code{guix system}
31114 Once you have written an operating system declaration as seen in the
31115 previous section, it can be @dfn{instantiated} using the @command{guix
31116 system} command. The synopsis is:
31119 guix system @var{options}@dots{} @var{action} @var{file}
31122 @var{file} must be the name of a file containing an
31123 @code{operating-system} declaration. @var{action} specifies how the
31124 operating system is instantiated. Currently the following values are
31129 Display available service type definitions that match the given regular
31130 expressions, sorted by relevance:
31136 $ guix system search console
31137 name: console-fonts
31138 location: gnu/services/base.scm:806:2
31139 extends: shepherd-root
31140 description: Install the given fonts on the specified ttys (fonts are per
31141 + virtual console on GNU/Linux). The value of this service is a list of
31142 + tty/font pairs. The font can be the name of a font provided by the `kbd'
31143 + package or any valid argument to `setfont', as in this example:
31145 + '(("tty1" . "LatGrkCyr-8x16")
31146 + ("tty2" . (file-append
31148 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
31149 + ("tty3" . (file-append
31151 + "/share/consolefonts/ter-132n"))) ; for HDPI
31155 location: gnu/services/base.scm:1190:2
31156 extends: shepherd-root
31157 description: Provide console login using the `mingetty' program.
31161 location: gnu/services/base.scm:860:2
31163 description: Provide a console log-in service as specified by its
31164 + configuration value, a `login-configuration' object.
31170 As for @command{guix package --search}, the result is written in
31171 @code{recutils} format, which makes it easy to filter the output
31172 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
31175 Build the operating system described in @var{file}, activate it, and
31176 switch to it@footnote{This action (and the related actions
31177 @code{switch-generation} and @code{roll-back}) are usable only on
31178 systems already running Guix System.}.
31181 @c The paragraph below refers to the problem discussed at
31182 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
31183 It is highly recommended to run @command{guix pull} once before you run
31184 @command{guix system reconfigure} for the first time (@pxref{Invoking
31185 guix pull}). Failing to do that you would see an older version of Guix
31186 once @command{reconfigure} has completed.
31189 This effects all the configuration specified in @var{file}: user
31190 accounts, system services, global package list, setuid programs, etc.
31191 The command starts system services specified in @var{file} that are not
31192 currently running; if a service is currently running this command will
31193 arrange for it to be upgraded the next time it is stopped (e.g.@: by
31194 @code{herd stop X} or @code{herd restart X}).
31196 This command creates a new generation whose number is one greater than
31197 the current generation (as reported by @command{guix system
31198 list-generations}). If that generation already exists, it will be
31199 overwritten. This behavior mirrors that of @command{guix package}
31200 (@pxref{Invoking guix package}).
31202 It also adds a bootloader menu entry for the new OS configuration,
31203 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
31204 entries for older configurations to a submenu, allowing you to choose
31205 an older system generation at boot time should you need it.
31207 @cindex provenance tracking, of the operating system
31208 Upon completion, the new system is deployed under
31209 @file{/run/current-system}. This directory contains @dfn{provenance
31210 meta-data}: the list of channels in use (@pxref{Channels}) and
31211 @var{file} itself, when available. You can view it by running:
31214 guix system describe
31217 This information is useful should you later want to inspect how this
31218 particular generation was built. In fact, assuming @var{file} is
31219 self-contained, you can later rebuild generation @var{n} of your
31220 operating system with:
31223 guix time-machine \
31224 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
31225 system reconfigure \
31226 /var/guix/profiles/system-@var{n}-link/configuration.scm
31229 You can think of it as some sort of built-in version control! Your
31230 system is not just a binary artifact: @emph{it carries its own source}.
31231 @xref{Service Reference, @code{provenance-service-type}}, for more
31232 information on provenance tracking.
31234 By default, @command{reconfigure} @emph{prevents you from downgrading
31235 your system}, which could (re)introduce security vulnerabilities and
31236 also cause problems with ``stateful'' services such as database
31237 management systems. You can override that behavior by passing
31238 @option{--allow-downgrades}.
31240 @item switch-generation
31241 @cindex generations
31242 Switch to an existing system generation. This action atomically
31243 switches the system profile to the specified system generation. It
31244 also rearranges the system's existing bootloader menu entries. It
31245 makes the menu entry for the specified system generation the default,
31246 and it moves the entries for the other generations to a submenu, if
31247 supported by the bootloader being used. The next time the system
31248 boots, it will use the specified system generation.
31250 The bootloader itself is not being reinstalled when using this
31251 command. Thus, the installed bootloader is used with an updated
31252 configuration file.
31254 The target generation can be specified explicitly by its generation
31255 number. For example, the following invocation would switch to system
31259 guix system switch-generation 7
31262 The target generation can also be specified relative to the current
31263 generation with the form @code{+N} or @code{-N}, where @code{+3} means
31264 ``3 generations ahead of the current generation,'' and @code{-1} means
31265 ``1 generation prior to the current generation.'' When specifying a
31266 negative value such as @code{-1}, you must precede it with @code{--} to
31267 prevent it from being parsed as an option. For example:
31270 guix system switch-generation -- -1
31273 Currently, the effect of invoking this action is @emph{only} to switch
31274 the system profile to an existing generation and rearrange the
31275 bootloader menu entries. To actually start using the target system
31276 generation, you must reboot after running this action. In the future,
31277 it will be updated to do the same things as @command{reconfigure},
31278 like activating and deactivating services.
31280 This action will fail if the specified generation does not exist.
31283 @cindex rolling back
31284 Switch to the preceding system generation. The next time the system
31285 boots, it will use the preceding system generation. This is the inverse
31286 of @command{reconfigure}, and it is exactly the same as invoking
31287 @command{switch-generation} with an argument of @code{-1}.
31289 Currently, as with @command{switch-generation}, you must reboot after
31290 running this action to actually start using the preceding system
31293 @item delete-generations
31294 @cindex deleting system generations
31295 @cindex saving space
31296 Delete system generations, making them candidates for garbage collection
31297 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
31300 This works in the same way as @samp{guix package --delete-generations}
31301 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
31302 arguments, all system generations but the current one are deleted:
31305 guix system delete-generations
31308 You can also select the generations you want to delete. The example below
31309 deletes all the system generations that are more than two month old:
31312 guix system delete-generations 2m
31315 Running this command automatically reinstalls the bootloader with an updated
31316 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
31317 longer lists the generations that have been deleted.
31320 Build the derivation of the operating system, which includes all the
31321 configuration files and programs needed to boot and run the system.
31322 This action does not actually install anything.
31325 Populate the given directory with all the files necessary to run the
31326 operating system specified in @var{file}. This is useful for first-time
31327 installations of Guix System. For instance:
31330 guix system init my-os-config.scm /mnt
31333 copies to @file{/mnt} all the store items required by the configuration
31334 specified in @file{my-os-config.scm}. This includes configuration
31335 files, packages, and so on. It also creates other essential files
31336 needed for the system to operate correctly---e.g., the @file{/etc},
31337 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
31339 This command also installs bootloader on the target specified in
31340 @file{my-os-config}, unless the @option{--no-bootloader} option was
31344 @cindex virtual machine
31346 @anchor{guix system vm}
31347 Build a virtual machine that contains the operating system declared in
31348 @var{file}, and return a script to run that virtual machine (VM).
31351 The @code{vm} action and others below
31352 can use KVM support in the Linux-libre kernel. Specifically, if the
31353 machine has hardware virtualization support, the corresponding
31354 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
31355 must exist and be readable and writable by the user and by the
31356 build users of the daemon (@pxref{Build Environment Setup}).
31359 Arguments given to the script are passed to QEMU as in the example
31360 below, which enables networking and requests 1@tie{}GiB of RAM for the
31364 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
31367 The VM shares its store with the host system.
31369 Additional file systems can be shared between the host and the VM using
31370 the @option{--share} and @option{--expose} command-line options: the former
31371 specifies a directory to be shared with write access, while the latter
31372 provides read-only access to the shared directory.
31374 The example below creates a VM in which the user's home directory is
31375 accessible read-only, and where the @file{/exchange} directory is a
31376 read-write mapping of @file{$HOME/tmp} on the host:
31379 guix system vm my-config.scm \
31380 --expose=$HOME --share=$HOME/tmp=/exchange
31383 On GNU/Linux, the default is to boot directly to the kernel; this has
31384 the advantage of requiring only a very tiny root disk image since the
31385 store of the host can then be mounted.
31387 The @option{--full-boot} option forces a complete boot sequence, starting
31388 with the bootloader. This requires more disk space since a root image
31389 containing at least the kernel, initrd, and bootloader data files must
31390 be created. The @option{--image-size} option can be used to specify the
31393 @cindex System images, creation in various formats
31394 @cindex Creating system images in various formats
31397 @itemx docker-image
31398 Return a virtual machine, disk image, or Docker image of the operating
31399 system declared in @var{file} that stands alone. By default,
31400 @command{guix system} estimates the size of the image needed to store
31401 the system, but you can use the @option{--image-size} option to specify
31402 a value. Docker images are built to contain exactly what they need, so
31403 the @option{--image-size} option is ignored in the case of
31404 @code{docker-image}.
31406 @cindex disk-image, creating disk images
31407 The @code{disk-image} command can produce various image types. The
31408 image type can be selected using the @option{--image-type} option. It
31409 defaults to @code{raw}. When its value is @code{iso9660}, the
31410 @option{--label} option can be used to specify a volume ID with
31411 @code{disk-image}. By default, the root file system of a disk image is
31412 mounted non-volatile; the @option{--volatile} option can be provided to
31413 make it volatile instead. When using @code{disk-image}, the bootloader
31414 installed on the generated image is taken from the provided
31415 @code{operating-system} definition. The following example demonstrates
31416 how to generate an image that uses the @code{grub-efi-bootloader}
31417 bootloader and boot it with QEMU:
31420 image=$(guix system disk-image --image-type=qcow2 \
31421 gnu/system/examples/lightweight-desktop.tmpl)
31422 cp $image /tmp/my-image.qcow2
31423 chmod +w /tmp/my-image.qcow2
31424 qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
31425 -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
31428 When using the @code{raw} image type, a raw disk image is produced; it
31429 can be copied as is to a USB stick, for instance. Assuming
31430 @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
31431 the image to it using the following command:
31434 # dd if=$(guix system disk-image my-os.scm) of=/dev/sdc status=progress
31437 The @code{--list-image-types} command lists all the available image
31440 @cindex vm-image, creating virtual machine images
31441 When using @code{vm-image}, the returned image is in qcow2 format, which
31442 the QEMU emulator can efficiently use. @xref{Running Guix in a VM}, for
31443 more information on how to run the image in a virtual machine. The
31444 @code{grub-bootloader} bootloader is always used independently of what
31445 is declared in the @code{operating-system} file passed as argument.
31446 This is to make it easier to work with QEMU, which uses the SeaBIOS BIOS
31447 by default, expecting a bootloader to be installed in the Master Boot
31450 @cindex docker-image, creating docker images
31451 When using @code{docker-image}, a Docker image is produced. Guix builds
31452 the image from scratch, not from a pre-existing Docker base image. As a
31453 result, it contains @emph{exactly} what you define in the operating
31454 system configuration file. You can then load the image and launch a
31455 Docker container using commands like the following:
31458 image_id="`docker load < guix-system-docker-image.tar.gz`"
31459 container_id="`docker create $image_id`"
31460 docker start $container_id
31463 This command starts a new Docker container from the specified image. It
31464 will boot the Guix system in the usual manner, which means it will
31465 start any services you have defined in the operating system
31466 configuration. You can get an interactive shell running in the container
31467 using @command{docker exec}:
31470 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
31473 Depending on what you run in the Docker container, it
31474 may be necessary to give the container additional permissions. For
31475 example, if you intend to build software using Guix inside of the Docker
31476 container, you may need to pass the @option{--privileged} option to
31477 @code{docker create}.
31479 Last, the @option{--network} option applies to @command{guix system
31480 docker-image}: it produces an image where network is supposedly shared
31481 with the host, and thus without services like nscd or NetworkManager.
31484 Return a script to run the operating system declared in @var{file}
31485 within a container. Containers are a set of lightweight isolation
31486 mechanisms provided by the kernel Linux-libre. Containers are
31487 substantially less resource-demanding than full virtual machines since
31488 the kernel, shared objects, and other resources can be shared with the
31489 host system; this also means they provide thinner isolation.
31491 Currently, the script must be run as root in order to support more than
31492 a single user and group. The container shares its store with the host
31495 As with the @code{vm} action (@pxref{guix system vm}), additional file
31496 systems to be shared between the host and container can be specified
31497 using the @option{--share} and @option{--expose} options:
31500 guix system container my-config.scm \
31501 --expose=$HOME --share=$HOME/tmp=/exchange
31505 This option requires Linux-libre 3.19 or newer.
31510 @var{options} can contain any of the common build options (@pxref{Common
31511 Build Options}). In addition, @var{options} can contain one of the
31515 @item --expression=@var{expr}
31516 @itemx -e @var{expr}
31517 Consider the operating-system @var{expr} evaluates to.
31518 This is an alternative to specifying a file which evaluates to an
31520 This is used to generate the Guix system installer @pxref{Building the
31521 Installation Image}).
31523 @item --system=@var{system}
31524 @itemx -s @var{system}
31525 Attempt to build for @var{system} instead of the host system type.
31526 This works as per @command{guix build} (@pxref{Invoking guix build}).
31530 Return the derivation file name of the given operating system without
31533 @cindex provenance tracking, of the operating system
31534 @item --save-provenance
31535 As discussed above, @command{guix system init} and @command{guix system
31536 reconfigure} always save provenance information @i{via} a dedicated
31537 service (@pxref{Service Reference, @code{provenance-service-type}}).
31538 However, other commands don't do that by default. If you wish to, say,
31539 create a virtual machine image that contains provenance information, you
31543 guix system vm-image --save-provenance config.scm
31546 That way, the resulting image will effectively ``embed its own source''
31547 in the form of meta-data in @file{/run/current-system}. With that
31548 information, one can rebuild the image to make sure it really contains
31549 what it pretends to contain; or they could use that to derive a variant
31552 @item --image-type=@var{type}
31553 @itemx -t @var{type}
31554 For the @code{disk-image} action, create an image with given @var{type}.
31556 When this option is omitted, @command{guix system} uses the @code{raw}
31559 @cindex ISO-9660 format
31560 @cindex CD image format
31561 @cindex DVD image format
31562 @option{--image-type=iso9660} produces an ISO-9660 image, suitable
31563 for burning on CDs and DVDs.
31565 @item --image-size=@var{size}
31566 For the @code{vm-image} and @code{disk-image} actions, create an image
31567 of the given @var{size}. @var{size} may be a number of bytes, or it may
31568 include a unit as a suffix (@pxref{Block size, size specifications,,
31569 coreutils, GNU Coreutils}).
31571 When this option is omitted, @command{guix system} computes an estimate
31572 of the image size as a function of the size of the system declared in
31577 For the @code{container} action, allow containers to access the host network,
31578 that is, do not create a network namespace.
31580 @item --root=@var{file}
31581 @itemx -r @var{file}
31582 Make @var{file} a symlink to the result, and register it as a garbage
31585 @item --skip-checks
31586 Skip pre-installation safety checks.
31588 By default, @command{guix system init} and @command{guix system
31589 reconfigure} perform safety checks: they make sure the file systems that
31590 appear in the @code{operating-system} declaration actually exist
31591 (@pxref{File Systems}), and that any Linux kernel modules that may be
31592 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
31593 RAM Disk}). Passing this option skips these tests altogether.
31595 @item --allow-downgrades
31596 Instruct @command{guix system reconfigure} to allow system downgrades.
31598 By default, @command{reconfigure} prevents you from downgrading your
31599 system. It achieves that by comparing the provenance info of your
31600 system (shown by @command{guix system describe}) with that of your
31601 @command{guix} command (shown by @command{guix describe}). If the
31602 commits for @command{guix} are not descendants of those used for your
31603 system, @command{guix system reconfigure} errors out. Passing
31604 @option{--allow-downgrades} allows you to bypass these checks.
31607 Make sure you understand its security implications before using
31608 @option{--allow-downgrades}.
31612 @cindex on-error strategy
31613 @cindex error strategy
31614 @item --on-error=@var{strategy}
31615 Apply @var{strategy} when an error occurs when reading @var{file}.
31616 @var{strategy} may be one of the following:
31619 @item nothing-special
31620 Report the error concisely and exit. This is the default strategy.
31623 Likewise, but also display a backtrace.
31626 Report the error and enter Guile's debugger. From there, you can run
31627 commands such as @code{,bt} to get a backtrace, @code{,locals} to
31628 display local variable values, and more generally inspect the state of the
31629 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
31630 a list of available debugging commands.
31634 Once you have built, configured, re-configured, and re-re-configured
31635 your Guix installation, you may find it useful to list the operating
31636 system generations available on disk---and that you can choose from the
31637 bootloader boot menu:
31642 Describe the current system generation: its file name, the kernel and
31643 bootloader used, etc., as well as provenance information when available.
31645 @item list-generations
31646 List a summary of each generation of the operating system available on
31647 disk, in a human-readable way. This is similar to the
31648 @option{--list-generations} option of @command{guix package}
31649 (@pxref{Invoking guix package}).
31651 Optionally, one can specify a pattern, with the same syntax that is used
31652 in @command{guix package --list-generations}, to restrict the list of
31653 generations displayed. For instance, the following command displays
31654 generations that are up to 10 days old:
31657 $ guix system list-generations 10d
31662 The @command{guix system} command has even more to offer! The following
31663 sub-commands allow you to visualize how your system services relate to
31666 @anchor{system-extension-graph}
31669 @item extension-graph
31670 Emit to standard output the @dfn{service
31671 extension graph} of the operating system defined in @var{file}
31672 (@pxref{Service Composition}, for more information on service
31673 extensions). By default the output is in Dot/Graphviz format, but you
31674 can choose a different format with @option{--graph-backend}, as with
31675 @command{guix graph} (@pxref{Invoking guix graph, @option{--backend}}):
31680 $ guix system extension-graph @var{file} | xdot -
31683 shows the extension relations among services.
31685 @anchor{system-shepherd-graph}
31686 @item shepherd-graph
31687 Emit to standard output the @dfn{dependency
31688 graph} of shepherd services of the operating system defined in
31689 @var{file}. @xref{Shepherd Services}, for more information and for an
31692 Again, the default output format is Dot/Graphviz, but you can pass
31693 @option{--graph-backend} to select a different one.
31697 @node Invoking guix deploy
31698 @section Invoking @code{guix deploy}
31700 We've already seen @code{operating-system} declarations used to manage a
31701 machine's configuration locally. Suppose you need to configure multiple
31702 machines, though---perhaps you're managing a service on the web that's
31703 comprised of several servers. @command{guix deploy} enables you to use those
31704 same @code{operating-system} declarations to manage multiple remote hosts at
31705 once as a logical ``deployment''.
31708 The functionality described in this section is still under development
31709 and is subject to change. Get in touch with us on
31710 @email{guix-devel@@gnu.org}!
31714 guix deploy @var{file}
31717 Such an invocation will deploy the machines that the code within @var{file}
31718 evaluates to. As an example, @var{file} might contain a definition like this:
31721 ;; This is a Guix deployment of a "bare bones" setup, with
31722 ;; no X11 display server, to a machine with an SSH daemon
31723 ;; listening on localhost:2222. A configuration such as this
31724 ;; may be appropriate for virtual machine with ports
31725 ;; forwarded to the host's loopback interface.
31727 (use-service-modules networking ssh)
31728 (use-package-modules bootloaders)
31732 (host-name "gnu-deployed")
31733 (timezone "Etc/UTC")
31734 (bootloader (bootloader-configuration
31735 (bootloader grub-bootloader)
31736 (target "/dev/vda")
31737 (terminal-outputs '(console))))
31738 (file-systems (cons (file-system
31740 (device "/dev/vda1")
31742 %base-file-systems))
31744 (append (list (service dhcp-client-service-type)
31745 (service openssh-service-type
31746 (openssh-configuration
31747 (permit-root-login #t)
31748 (allow-empty-passwords? #t))))
31752 (operating-system %system)
31753 (environment managed-host-environment-type)
31754 (configuration (machine-ssh-configuration
31755 (host-name "localhost")
31756 (system "x86_64-linux")
31758 (identity "./id_rsa")
31762 The file should evaluate to a list of @var{machine} objects. This example,
31763 upon being deployed, will create a new generation on the remote system
31764 realizing the @code{operating-system} declaration @code{%system}.
31765 @code{environment} and @code{configuration} specify how the machine should be
31766 provisioned---that is, how the computing resources should be created and
31767 managed. The above example does not create any resources, as a
31768 @code{'managed-host} is a machine that is already running the Guix system and
31769 available over the network. This is a particularly simple case; a more
31770 complex deployment may involve, for example, starting virtual machines through
31771 a Virtual Private Server (VPS) provider. In such a case, a different
31772 @var{environment} type would be used.
31774 Do note that you first need to generate a key pair on the coordinator machine
31775 to allow the daemon to export signed archives of files from the store
31776 (@pxref{Invoking guix archive}), though this step is automatic on Guix
31780 # guix archive --generate-key
31784 Each target machine must authorize the key of the master machine so that it
31785 accepts store items it receives from the coordinator:
31788 # guix archive --authorize < coordinator-public-key.txt
31791 @code{user}, in this example, specifies the name of the user account to log in
31792 as to perform the deployment. Its default value is @code{root}, but root
31793 login over SSH may be forbidden in some cases. To work around this,
31794 @command{guix deploy} can log in as an unprivileged user and employ
31795 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
31796 currently installed on the remote and can be invoked non-interactively as
31797 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
31798 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
31799 be accomplished with the following operating system configuration snippet:
31803 (gnu system)) ;for %sudoers-specification
31805 (define %user "username")
31810 (plain-file "sudoers"
31811 (string-append (plain-file-content %sudoers-specification)
31812 (format #f "~a ALL = NOPASSWD: ALL~%"
31817 For more information regarding the format of the @file{sudoers} file,
31818 consult @command{man sudoers}.
31820 @deftp {Data Type} machine
31821 This is the data type representing a single machine in a heterogeneous Guix
31825 @item @code{operating-system}
31826 The object of the operating system configuration to deploy.
31828 @item @code{environment}
31829 An @code{environment-type} describing how the machine should be provisioned.
31831 @item @code{configuration} (default: @code{#f})
31832 An object describing the configuration for the machine's @code{environment}.
31833 If the @code{environment} has a default configuration, @code{#f} may be used.
31834 If @code{#f} is used for an environment with no default configuration,
31835 however, an error will be thrown.
31839 @deftp {Data Type} machine-ssh-configuration
31840 This is the data type representing the SSH client parameters for a machine
31841 with an @code{environment} of @code{managed-host-environment-type}.
31844 @item @code{host-name}
31845 @item @code{build-locally?} (default: @code{#t})
31846 If false, system derivations will be built on the machine being deployed to.
31847 @item @code{system}
31848 The system type describing the architecture of the machine being deployed
31849 to---e.g., @code{"x86_64-linux"}.
31850 @item @code{authorize?} (default: @code{#t})
31851 If true, the coordinator's signing key will be added to the remote's ACL
31853 @item @code{port} (default: @code{22})
31854 @item @code{user} (default: @code{"root"})
31855 @item @code{identity} (default: @code{#f})
31856 If specified, the path to the SSH private key to use to authenticate with the
31859 @item @code{host-key} (default: @code{#f})
31860 This should be the SSH host key of the machine, which looks like this:
31863 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
31866 When @code{host-key} is @code{#f}, the server is authenticated against
31867 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
31870 @item @code{allow-downgrades?} (default: @code{#f})
31871 Whether to allow potential downgrades.
31873 Like @command{guix system reconfigure}, @command{guix deploy} compares
31874 the channel commits currently deployed on the remote host (as returned
31875 by @command{guix system describe}) to those currently in use (as
31876 returned by @command{guix describe}) to determine whether commits
31877 currently in use are descendants of those deployed. When this is not
31878 the case and @code{allow-downgrades?} is false, it raises an error.
31879 This ensures you do not accidentally downgrade remote machines.
31883 @deftp {Data Type} digital-ocean-configuration
31884 This is the data type describing the Droplet that should be created for a
31885 machine with an @code{environment} of @code{digital-ocean-environment-type}.
31888 @item @code{ssh-key}
31889 The path to the SSH private key to use to authenticate with the remote
31890 host. In the future, this field may not exist.
31892 A list of string ``tags'' that uniquely identify the machine. Must be given
31893 such that no two machines in the deployment have the same set of tags.
31894 @item @code{region}
31895 A Digital Ocean region slug, such as @code{"nyc3"}.
31897 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
31898 @item @code{enable-ipv6?}
31899 Whether or not the droplet should be created with IPv6 networking.
31903 @node Running Guix in a VM
31904 @section Running Guix in a Virtual Machine
31906 @cindex virtual machine
31907 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
31909 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
31910 This image is a compressed image in QCOW format. You will first need to
31911 decompress with @command{xz -d}, and then you can pass it to an emulator such
31912 as QEMU (see below for details).
31914 This image boots the Xfce graphical environment and it contains some
31915 commonly used tools. You can install more software in the image by running
31916 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
31917 also reconfigure the system based on its initial configuration file available
31918 as @file{/run/current-system/configuration.scm} (@pxref{Using the
31919 Configuration System}).
31921 Instead of using this pre-built image, one can also build their own virtual
31922 machine image using @command{guix system vm-image} (@pxref{Invoking guix
31923 system}). The returned image is in qcow2 format, which the
31924 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
31927 If you built your own image, you must copy it out of the store
31928 (@pxref{The Store}) and give yourself permission to write to the copy
31929 before you can use it. When invoking QEMU, you must choose a system
31930 emulator that is suitable for your hardware platform. Here is a minimal
31931 QEMU invocation that will boot the result of @command{guix system
31932 vm-image} on x86_64 hardware:
31935 $ qemu-system-x86_64 \
31936 -nic user,model=virtio-net-pci \
31937 -enable-kvm -m 1024 \
31938 -device virtio-blk,drive=myhd \
31939 -drive if=none,file=/tmp/qemu-image,id=myhd
31942 Here is what each of these options means:
31945 @item qemu-system-x86_64
31946 This specifies the hardware platform to emulate. This should match the
31949 @item -nic user,model=virtio-net-pci
31950 Enable the unprivileged user-mode network stack. The guest OS can
31951 access the host but not vice versa. This is the simplest way to get the
31952 guest OS online. @code{model} specifies which network device to emulate:
31953 @code{virtio-net-pci} is a special device made for virtualized operating
31954 systems and recommended for most uses. Assuming your hardware platform is
31955 x86_64, you can get a list of available NIC models by running
31956 @command{qemu-system-x86_64 -nic model=help}.
31959 If your system has hardware virtualization extensions, enabling the
31960 virtual machine support (KVM) of the Linux kernel will make things run
31963 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
31965 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
31966 which may be insufficient for some operations.
31968 @item -device virtio-blk,drive=myhd
31969 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
31970 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
31971 better performance than if it were emulating a complete disk drive. See the
31972 QEMU and KVM documentation for more info.
31974 @item -drive if=none,file=/tmp/qemu-image,id=myhd
31975 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
31976 store of the ``myhd'' drive.
31979 The default @command{run-vm.sh} script that is returned by an invocation of
31980 @command{guix system vm} does not add a @command{-nic user} flag by default.
31981 To get network access from within the vm add the @code{(dhcp-client-service)}
31982 to your system definition and start the VM using
31983 @command{`guix system vm config.scm` -nic user}. An important caveat of using
31984 @command{-nic user} for networking is that @command{ping} will not work, because
31985 it uses the ICMP protocol. You'll have to use a different command to check for
31986 network connectivity, for example @command{guix download}.
31988 @subsection Connecting Through SSH
31992 To enable SSH inside a VM you need to add an SSH server like
31993 @code{openssh-service-type} to your VM (@pxref{Networking Services,
31994 @code{openssh-service-type}}). In addition you need to forward the SSH port,
31995 22 by default, to the host. You can do this with
31998 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
32001 To connect to the VM you can run
32004 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
32007 The @command{-p} tells @command{ssh} the port you want to connect to.
32008 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
32009 every time you modify your @command{config.scm} file and the
32010 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
32011 connection to an unknown host every time you connect.
32013 @subsection Using @command{virt-viewer} with Spice
32015 As an alternative to the default @command{qemu} graphical client you can
32016 use the @command{remote-viewer} from the @command{virt-viewer} package. To
32017 connect pass the @command{-spice port=5930,disable-ticketing} flag to
32018 @command{qemu}. See previous section for further information on how to do this.
32020 Spice also allows you to do some nice stuff like share your clipboard with your
32021 VM. To enable that you'll also have to pass the following flags to @command{qemu}:
32024 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
32025 -chardev spicevmc,name=vdagent,id=vdagent
32026 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
32027 name=com.redhat.spice.0
32030 You'll also need to add the @code{(spice-vdagent-service)} to your
32031 system definition (@pxref{Miscellaneous Services, Spice service}).
32033 @node Defining Services
32034 @section Defining Services
32036 The previous sections show the available services and how one can combine
32037 them in an @code{operating-system} declaration. But how do we define
32038 them in the first place? And what is a service anyway?
32041 * Service Composition:: The model for composing services.
32042 * Service Types and Services:: Types and services.
32043 * Service Reference:: API reference.
32044 * Shepherd Services:: A particular type of service.
32047 @node Service Composition
32048 @subsection Service Composition
32052 Here we define a @dfn{service} as, broadly, something that extends the
32053 functionality of the operating system. Often a service is a process---a
32054 @dfn{daemon}---started when the system boots: a secure shell server, a
32055 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
32056 whose execution can be triggered by another daemon---e.g., an FTP server
32057 started by @command{inetd} or a D-Bus service activated by
32058 @command{dbus-daemon}. Occasionally, a service does not map to a
32059 daemon. For instance, the ``account'' service collects user accounts
32060 and makes sure they exist when the system runs; the ``udev'' service
32061 collects device management rules and makes them available to the eudev
32062 daemon; the @file{/etc} service populates the @file{/etc} directory
32065 @cindex service extensions
32066 Guix system services are connected by @dfn{extensions}. For instance, the
32067 secure shell service @emph{extends} the Shepherd---the
32068 initialization system, running as PID@tie{}1---by giving it the command
32069 lines to start and stop the secure shell daemon (@pxref{Networking
32070 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
32071 service by passing it its @file{.service} specification, and extends the
32072 udev service by passing it device management rules (@pxref{Desktop
32073 Services, @code{upower-service}}); the Guix daemon service extends the
32074 Shepherd by passing it the command lines to start and stop the daemon,
32075 and extends the account service by passing it a list of required build
32076 user accounts (@pxref{Base Services}).
32078 All in all, services and their ``extends'' relations form a directed
32079 acyclic graph (DAG). If we represent services as boxes and extensions
32080 as arrows, a typical system might provide something like this:
32082 @image{images/service-graph,,5in,Typical service extension graph.}
32084 @cindex system service
32085 At the bottom, we see the @dfn{system service}, which produces the
32086 directory containing everything to run and boot the system, as returned
32087 by the @command{guix system build} command. @xref{Service Reference},
32088 to learn about the other service types shown here.
32089 @xref{system-extension-graph, the @command{guix system extension-graph}
32090 command}, for information on how to generate this representation for a
32091 particular operating system definition.
32093 @cindex service types
32094 Technically, developers can define @dfn{service types} to express these
32095 relations. There can be any number of services of a given type on the
32096 system---for instance, a system running two instances of the GNU secure
32097 shell server (lsh) has two instances of @code{lsh-service-type}, with
32098 different parameters.
32100 The following section describes the programming interface for service
32101 types and services.
32103 @node Service Types and Services
32104 @subsection Service Types and Services
32106 A @dfn{service type} is a node in the DAG described above. Let us start
32107 with a simple example, the service type for the Guix build daemon
32108 (@pxref{Invoking guix-daemon}):
32111 (define guix-service-type
32115 (list (service-extension shepherd-root-service-type guix-shepherd-service)
32116 (service-extension account-service-type guix-accounts)
32117 (service-extension activation-service-type guix-activation)))
32118 (default-value (guix-configuration))))
32122 It defines three things:
32126 A name, whose sole purpose is to make inspection and debugging easier.
32129 A list of @dfn{service extensions}, where each extension designates the
32130 target service type and a procedure that, given the parameters of the
32131 service, returns a list of objects to extend the service of that type.
32133 Every service type has at least one service extension. The only
32134 exception is the @dfn{boot service type}, which is the ultimate service.
32137 Optionally, a default value for instances of this type.
32140 In this example, @code{guix-service-type} extends three services:
32143 @item shepherd-root-service-type
32144 The @code{guix-shepherd-service} procedure defines how the Shepherd
32145 service is extended. Namely, it returns a @code{<shepherd-service>}
32146 object that defines how @command{guix-daemon} is started and stopped
32147 (@pxref{Shepherd Services}).
32149 @item account-service-type
32150 This extension for this service is computed by @code{guix-accounts},
32151 which returns a list of @code{user-group} and @code{user-account}
32152 objects representing the build user accounts (@pxref{Invoking
32155 @item activation-service-type
32156 Here @code{guix-activation} is a procedure that returns a gexp, which is
32157 a code snippet to run at ``activation time''---e.g., when the service is
32161 A service of this type is instantiated like this:
32164 (service guix-service-type
32165 (guix-configuration
32167 (extra-options '("--gc-keep-derivations"))))
32170 The second argument to the @code{service} form is a value representing
32171 the parameters of this specific service instance.
32172 @xref{guix-configuration-type, @code{guix-configuration}}, for
32173 information about the @code{guix-configuration} data type. When the
32174 value is omitted, the default value specified by
32175 @code{guix-service-type} is used:
32178 (service guix-service-type)
32181 @code{guix-service-type} is quite simple because it extends other
32182 services but is not extensible itself.
32184 @c @subsubsubsection Extensible Service Types
32186 The service type for an @emph{extensible} service looks like this:
32189 (define udev-service-type
32190 (service-type (name 'udev)
32192 (list (service-extension shepherd-root-service-type
32193 udev-shepherd-service)))
32195 (compose concatenate) ;concatenate the list of rules
32196 (extend (lambda (config rules)
32198 (($ <udev-configuration> udev initial-rules)
32199 (udev-configuration
32200 (udev udev) ;the udev package to use
32201 (rules (append initial-rules rules)))))))))
32204 This is the service type for the
32205 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
32206 management daemon}. Compared to the previous example, in addition to an
32207 extension of @code{shepherd-root-service-type}, we see two new fields:
32211 This is the procedure to @dfn{compose} the list of extensions to
32212 services of this type.
32214 Services can extend the udev service by passing it lists of rules; we
32215 compose those extensions simply by concatenating them.
32218 This procedure defines how the value of the service is @dfn{extended} with
32219 the composition of the extensions.
32221 Udev extensions are composed into a list of rules, but the udev service
32222 value is itself a @code{<udev-configuration>} record. So here, we
32223 extend that record by appending the list of rules it contains to the
32224 list of contributed rules.
32227 This is a string giving an overview of the service type. The string can
32228 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
32229 @command{guix system search} command searches these strings and displays
32230 them (@pxref{Invoking guix system}).
32233 There can be only one instance of an extensible service type such as
32234 @code{udev-service-type}. If there were more, the
32235 @code{service-extension} specifications would be ambiguous.
32237 Still here? The next section provides a reference of the programming
32238 interface for services.
32240 @node Service Reference
32241 @subsection Service Reference
32243 We have seen an overview of service types (@pxref{Service Types and
32244 Services}). This section provides a reference on how to manipulate
32245 services and service types. This interface is provided by the
32246 @code{(gnu services)} module.
32248 @deffn {Scheme Procedure} service @var{type} [@var{value}]
32249 Return a new service of @var{type}, a @code{<service-type>} object (see
32250 below). @var{value} can be any object; it represents the parameters of
32251 this particular service instance.
32253 When @var{value} is omitted, the default value specified by @var{type}
32254 is used; if @var{type} does not specify a default value, an error is
32257 For instance, this:
32260 (service openssh-service-type)
32264 is equivalent to this:
32267 (service openssh-service-type
32268 (openssh-configuration))
32271 In both cases the result is an instance of @code{openssh-service-type}
32272 with the default configuration.
32275 @deffn {Scheme Procedure} service? @var{obj}
32276 Return true if @var{obj} is a service.
32279 @deffn {Scheme Procedure} service-kind @var{service}
32280 Return the type of @var{service}---i.e., a @code{<service-type>} object.
32283 @deffn {Scheme Procedure} service-value @var{service}
32284 Return the value associated with @var{service}. It represents its
32288 Here is an example of how a service is created and manipulated:
32292 (service nginx-service-type
32293 (nginx-configuration
32295 (log-directory log-directory)
32296 (run-directory run-directory)
32297 (file config-file))))
32302 (eq? (service-kind s) nginx-service-type)
32306 The @code{modify-services} form provides a handy way to change the
32307 parameters of some of the services of a list such as
32308 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
32309 evaluates to a list of services. Of course, you could always use
32310 standard list combinators such as @code{map} and @code{fold} to do that
32311 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
32312 @code{modify-services} simply provides a more concise form for this
32315 @deffn {Scheme Syntax} modify-services @var{services} @
32316 (@var{type} @var{variable} => @var{body}) @dots{}
32318 Modify the services listed in @var{services} according to the given
32319 clauses. Each clause has the form:
32322 (@var{type} @var{variable} => @var{body})
32325 where @var{type} is a service type---e.g.,
32326 @code{guix-service-type}---and @var{variable} is an identifier that is
32327 bound within the @var{body} to the service parameters---e.g., a
32328 @code{guix-configuration} instance---of the original service of that
32331 The @var{body} should evaluate to the new service parameters, which will
32332 be used to configure the new service. This new service will replace the
32333 original in the resulting list. Because a service's service parameters
32334 are created using @code{define-record-type*}, you can write a succinct
32335 @var{body} that evaluates to the new service parameters by using the
32336 @code{inherit} feature that @code{define-record-type*} provides.
32338 @xref{Using the Configuration System}, for example usage.
32342 Next comes the programming interface for service types. This is
32343 something you want to know when writing new service definitions, but not
32344 necessarily when simply looking for ways to customize your
32345 @code{operating-system} declaration.
32347 @deftp {Data Type} service-type
32348 @cindex service type
32349 This is the representation of a @dfn{service type} (@pxref{Service Types
32354 This is a symbol, used only to simplify inspection and debugging.
32356 @item @code{extensions}
32357 A non-empty list of @code{<service-extension>} objects (see below).
32359 @item @code{compose} (default: @code{#f})
32360 If this is @code{#f}, then the service type denotes services that cannot
32361 be extended---i.e., services that do not receive ``values'' from other
32364 Otherwise, it must be a one-argument procedure. The procedure is called
32365 by @code{fold-services} and is passed a list of values collected from
32366 extensions. It may return any single value.
32368 @item @code{extend} (default: @code{#f})
32369 If this is @code{#f}, services of this type cannot be extended.
32371 Otherwise, it must be a two-argument procedure: @code{fold-services}
32372 calls it, passing it the initial value of the service as the first
32373 argument and the result of applying @code{compose} to the extension
32374 values as the second argument. It must return a value that is a valid
32375 parameter value for the service instance.
32377 @item @code{description}
32378 This is a string, possibly using Texinfo markup, describing in a couple
32379 of sentences what the service is about. This string allows users to
32380 find about the service through @command{guix system search}
32381 (@pxref{Invoking guix system}).
32383 @item @code{default-value} (default: @code{&no-default-value})
32384 The default value associated for instances of this service type. This
32385 allows users to use the @code{service} form without its second argument:
32388 (service @var{type})
32391 The returned service in this case has the default value specified by
32395 @xref{Service Types and Services}, for examples.
32398 @deffn {Scheme Procedure} service-extension @var{target-type} @
32400 Return a new extension for services of type @var{target-type}.
32401 @var{compute} must be a one-argument procedure: @code{fold-services}
32402 calls it, passing it the value associated with the service that provides
32403 the extension; it must return a valid value for the target service.
32406 @deffn {Scheme Procedure} service-extension? @var{obj}
32407 Return true if @var{obj} is a service extension.
32410 Occasionally, you might want to simply extend an existing service. This
32411 involves creating a new service type and specifying the extension of
32412 interest, which can be verbose; the @code{simple-service} procedure
32413 provides a shorthand for this.
32415 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
32416 Return a service that extends @var{target} with @var{value}. This works
32417 by creating a singleton service type @var{name}, of which the returned
32418 service is an instance.
32420 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
32424 (simple-service 'my-mcron-job mcron-service-type
32425 #~(job '(next-hour (3)) "guix gc -F 2G"))
32429 At the core of the service abstraction lies the @code{fold-services}
32430 procedure, which is responsible for ``compiling'' a list of services
32431 down to a single directory that contains everything needed to boot and
32432 run the system---the directory shown by the @command{guix system build}
32433 command (@pxref{Invoking guix system}). In essence, it propagates
32434 service extensions down the service graph, updating each node parameters
32435 on the way, until it reaches the root node.
32437 @deffn {Scheme Procedure} fold-services @var{services} @
32438 [#:target-type @var{system-service-type}]
32439 Fold @var{services} by propagating their extensions down to the root of
32440 type @var{target-type}; return the root service adjusted accordingly.
32443 Lastly, the @code{(gnu services)} module also defines several essential
32444 service types, some of which are listed below.
32446 @defvr {Scheme Variable} system-service-type
32447 This is the root of the service graph. It produces the system directory
32448 as returned by the @command{guix system build} command.
32451 @defvr {Scheme Variable} boot-service-type
32452 The type of the ``boot service'', which produces the @dfn{boot script}.
32453 The boot script is what the initial RAM disk runs when booting.
32456 @defvr {Scheme Variable} etc-service-type
32457 The type of the @file{/etc} service. This service is used to create
32458 files under @file{/etc} and can be extended by
32459 passing it name/file tuples such as:
32462 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
32465 In this example, the effect would be to add an @file{/etc/issue} file
32466 pointing to the given file.
32469 @defvr {Scheme Variable} setuid-program-service-type
32470 Type for the ``setuid-program service''. This service collects lists of
32471 executable file names, passed as gexps, and adds them to the set of
32472 setuid-root programs on the system (@pxref{Setuid Programs}).
32475 @defvr {Scheme Variable} profile-service-type
32476 Type of the service that populates the @dfn{system profile}---i.e., the
32477 programs under @file{/run/current-system/profile}. Other services can
32478 extend it by passing it lists of packages to add to the system profile.
32481 @cindex provenance tracking, of the operating system
32482 @anchor{provenance-service-type}
32483 @defvr {Scheme Variable} provenance-service-type
32484 This is the type of the service that records @dfn{provenance meta-data}
32485 in the system itself. It creates several files under
32486 @file{/run/current-system}:
32490 This is a ``channel file'' that can be passed to @command{guix pull -C}
32491 or @command{guix time-machine -C}, and which describes the channels used
32492 to build the system, if that information was available
32493 (@pxref{Channels}).
32495 @item configuration.scm
32496 This is the file that was passed as the value for this
32497 @code{provenance-service-type} service. By default, @command{guix
32498 system reconfigure} automatically passes the OS configuration file it
32499 received on the command line.
32502 This contains the same information as the two other files but in a
32503 format that is more readily processable.
32506 In general, these two pieces of information (channels and configuration
32507 file) are enough to reproduce the operating system ``from source''.
32510 This information is necessary to rebuild your operating system, but it
32511 is not always sufficient. In particular, @file{configuration.scm}
32512 itself is insufficient if it is not self-contained---if it refers to
32513 external Guile modules or to extra files. If you want
32514 @file{configuration.scm} to be self-contained, we recommend that modules
32515 or files it refers to be part of a channel.
32517 Besides, provenance meta-data is ``silent'' in the sense that it does
32518 not change the bits contained in your system, @emph{except for the
32519 meta-data bits themselves}. Two different OS configurations or sets of
32520 channels can lead to the same system, bit-for-bit; when
32521 @code{provenance-service-type} is used, these two systems will have
32522 different meta-data and thus different store file names, which makes
32523 comparison less trivial.
32526 This service is automatically added to your operating system
32527 configuration when you use @command{guix system reconfigure},
32528 @command{guix system init}, or @command{guix deploy}.
32531 @node Shepherd Services
32532 @subsection Shepherd Services
32534 @cindex shepherd services
32536 @cindex init system
32537 The @code{(gnu services shepherd)} module provides a way to define
32538 services managed by the GNU@tie{}Shepherd, which is the
32539 initialization system---the first process that is started when the
32540 system boots, also known as PID@tie{}1
32541 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
32543 Services in the Shepherd can depend on each other. For instance, the
32544 SSH daemon may need to be started after the syslog daemon has been
32545 started, which in turn can only happen once all the file systems have
32546 been mounted. The simple operating system defined earlier (@pxref{Using
32547 the Configuration System}) results in a service graph like this:
32549 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
32551 You can actually generate such a graph for any operating system
32552 definition using the @command{guix system shepherd-graph} command
32553 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
32555 The @code{%shepherd-root-service} is a service object representing
32556 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
32557 by passing it lists of @code{<shepherd-service>} objects.
32559 @deftp {Data Type} shepherd-service
32560 The data type representing a service managed by the Shepherd.
32563 @item @code{provision}
32564 This is a list of symbols denoting what the service provides.
32566 These are the names that may be passed to @command{herd start},
32567 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
32568 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
32569 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
32571 @item @code{requirement} (default: @code{'()})
32572 List of symbols denoting the Shepherd services this one depends on.
32574 @cindex one-shot services, for the Shepherd
32575 @item @code{one-shot?} (default: @code{#f})
32576 Whether this service is @dfn{one-shot}. One-shot services stop immediately
32577 after their @code{start} action has completed. @xref{Slots of services,,,
32578 shepherd, The GNU Shepherd Manual}, for more info.
32580 @item @code{respawn?} (default: @code{#t})
32581 Whether to restart the service when it stops, for instance when the
32582 underlying process dies.
32585 @itemx @code{stop} (default: @code{#~(const #f)})
32586 The @code{start} and @code{stop} fields refer to the Shepherd's
32587 facilities to start and stop processes (@pxref{Service De- and
32588 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
32589 G-expressions that get expanded in the Shepherd configuration file
32590 (@pxref{G-Expressions}).
32592 @item @code{actions} (default: @code{'()})
32593 @cindex actions, of Shepherd services
32594 This is a list of @code{shepherd-action} objects (see below) defining
32595 @dfn{actions} supported by the service, in addition to the standard
32596 @code{start} and @code{stop} actions. Actions listed here become available as
32597 @command{herd} sub-commands:
32600 herd @var{action} @var{service} [@var{arguments}@dots{}]
32603 @item @code{auto-start?} (default: @code{#t})
32604 Whether this service should be started automatically by the Shepherd. If it
32605 is @code{#f} the service has to be started manually with @code{herd start}.
32607 @item @code{documentation}
32608 A documentation string, as shown when running:
32611 herd doc @var{service-name}
32614 where @var{service-name} is one of the symbols in @code{provision}
32615 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
32617 @item @code{modules} (default: @code{%default-modules})
32618 This is the list of modules that must be in scope when @code{start} and
32619 @code{stop} are evaluated.
32624 @deftp {Data Type} shepherd-action
32625 This is the data type that defines additional actions implemented by a
32626 Shepherd service (see above).
32630 Symbol naming the action.
32632 @item documentation
32633 This is a documentation string for the action. It can be viewed by running:
32636 herd doc @var{service} action @var{action}
32640 This should be a gexp that evaluates to a procedure of at least one argument,
32641 which is the ``running value'' of the service (@pxref{Slots of services,,,
32642 shepherd, The GNU Shepherd Manual}).
32645 The following example defines an action called @code{say-hello} that kindly
32651 (documentation "Say hi!")
32652 (procedure #~(lambda (running . args)
32653 (format #t "Hello, friend! arguments: ~s\n"
32658 Assuming this action is added to the @code{example} service, then you can do:
32661 # herd say-hello example
32662 Hello, friend! arguments: ()
32663 # herd say-hello example a b c
32664 Hello, friend! arguments: ("a" "b" "c")
32667 This, as you can see, is a fairly sophisticated way to say hello.
32668 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
32672 @defvr {Scheme Variable} shepherd-root-service-type
32673 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
32675 This is the service type that extensions target when they want to create
32676 shepherd services (@pxref{Service Types and Services}, for an example).
32677 Each extension must pass a list of @code{<shepherd-service>}.
32680 @defvr {Scheme Variable} %shepherd-root-service
32681 This service represents PID@tie{}1.
32685 @node Documentation
32686 @chapter Documentation
32688 @cindex documentation, searching for
32689 @cindex searching for documentation
32690 @cindex Info, documentation format
32692 @cindex manual pages
32693 In most cases packages installed with Guix come with documentation.
32694 There are two main documentation formats: ``Info'', a browseable
32695 hypertext format used for GNU software, and ``manual pages'' (or ``man
32696 pages''), the linear documentation format traditionally found on Unix.
32697 Info manuals are accessed with the @command{info} command or with Emacs,
32698 and man pages are accessed using @command{man}.
32700 You can look for documentation of software installed on your system by
32701 keyword. For example, the following command searches for information
32702 about ``TLS'' in Info manuals:
32706 "(emacs)Network Security" -- STARTTLS
32707 "(emacs)Network Security" -- TLS
32708 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
32709 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
32714 The command below searches for the same keyword in man pages:
32718 SSL (7) - OpenSSL SSL/TLS library
32719 certtool (1) - GnuTLS certificate tool
32723 These searches are purely local to your computer so you have the
32724 guarantee that documentation you find corresponds to what you have
32725 actually installed, you can access it off-line, and your privacy is
32728 Once you have these results, you can view the relevant documentation by
32732 $ info "(gnutls)Core TLS API"
32742 Info manuals contain sections and indices as well as hyperlinks like
32743 those found in Web pages. The @command{info} reader (@pxref{Top, Info
32744 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
32745 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
32746 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
32747 Introduction}, for an introduction to Info navigation.
32749 @node Installing Debugging Files
32750 @chapter Installing Debugging Files
32752 @cindex debugging files
32753 Program binaries, as produced by the GCC compilers for instance, are
32754 typically written in the ELF format, with a section containing
32755 @dfn{debugging information}. Debugging information is what allows the
32756 debugger, GDB, to map binary code to source code; it is required to
32757 debug a compiled program in good conditions.
32759 This chapter explains how to use separate debug info when packages
32760 provide it, and how to rebuild packages with debug info when it's
32764 * Separate Debug Info:: Installing 'debug' outputs.
32765 * Rebuilding Debug Info:: Building missing debug info.
32768 @node Separate Debug Info
32769 @section Separate Debug Info
32771 The problem with debugging information is that is takes up a fair amount
32772 of disk space. For example, debugging information for the GNU C Library
32773 weighs in at more than 60 MiB. Thus, as a user, keeping all the
32774 debugging info of all the installed programs is usually not an option.
32775 Yet, space savings should not come at the cost of an impediment to
32776 debugging---especially in the GNU system, which should make it easier
32777 for users to exert their computing freedom (@pxref{GNU Distribution}).
32779 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
32780 mechanism that allows users to get the best of both worlds: debugging
32781 information can be stripped from the binaries and stored in separate
32782 files. GDB is then able to load debugging information from those files,
32783 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
32786 The GNU distribution takes advantage of this by storing debugging
32787 information in the @code{lib/debug} sub-directory of a separate package
32788 output unimaginatively called @code{debug} (@pxref{Packages with
32789 Multiple Outputs}). Users can choose to install the @code{debug} output
32790 of a package when they need it. For instance, the following command
32791 installs the debugging information for the GNU C Library and for GNU
32795 guix install glibc:debug guile:debug
32798 GDB must then be told to look for debug files in the user's profile, by
32799 setting the @code{debug-file-directory} variable (consider setting it
32800 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
32804 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
32807 From there on, GDB will pick up debugging information from the
32808 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
32810 In addition, you will most likely want GDB to be able to show the source
32811 code being debugged. To do that, you will have to unpack the source
32812 code of the package of interest (obtained with @code{guix build
32813 --source}, @pxref{Invoking guix build}), and to point GDB to that source
32814 directory using the @code{directory} command (@pxref{Source Path,
32815 @code{directory},, gdb, Debugging with GDB}).
32817 @c XXX: keep me up-to-date
32818 The @code{debug} output mechanism in Guix is implemented by the
32819 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
32820 opt-in---debugging information is available only for the packages with
32821 definitions explicitly declaring a @code{debug} output. To check
32822 whether a package has a @code{debug} output, use @command{guix package
32823 --list-available} (@pxref{Invoking guix package}).
32825 Read on for how to deal with packages lacking a @code{debug} output.
32827 @node Rebuilding Debug Info
32828 @section Rebuilding Debug Info
32830 @cindex debugging info, rebuilding
32831 As we saw above, some packages, but not all, provide debugging info in a
32832 @code{debug} output. What can you do when debugging info is missing?
32833 The @option{--with-debug-info} option provides a solution to that: it
32834 allows you to rebuild the package(s) for which debugging info is
32835 missing---and only those---and to graft those onto the application
32836 you're debugging. Thus, while it's not as fast as installing a
32837 @code{debug} output, it is relatively inexpensive.
32839 Let's illustrate that. Suppose you're experiencing a bug in Inkscape
32840 and would like to see what's going on in GLib, a library that's deep
32841 down in its dependency graph. As it turns out, GLib does not have a
32842 @code{debug} output and the backtrace GDB shows is all sadness:
32846 #0 0x00007ffff5f92190 in g_getenv ()
32847 from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
32848 #1 0x00007ffff608a7d6 in gobject_init_ctor ()
32849 from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
32850 #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
32851 env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
32852 #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
32856 To address that, you install Inkscape linked against a variant GLib that
32857 contains debug info:
32860 guix install inkscape --with-debug-info=glib
32863 This time, debugging will be a whole lot nicer:
32866 $ gdb --args sh -c 'exec inkscape'
32869 Function "g_getenv" not defined.
32870 Make breakpoint pending on future shared library load? (y or [n]) y
32871 Breakpoint 1 (g_getenv) pending.
32873 Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
32876 #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
32877 #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
32878 #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
32879 #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
32880 env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
32886 Note that there can be packages for which @option{--with-debug-info}
32887 will not have the desired effect. @xref{Package Transformation Options,
32888 @option{--with-debug-info}}, for more information.
32890 @node Security Updates
32891 @chapter Security Updates
32893 @cindex security updates
32894 @cindex security vulnerabilities
32895 Occasionally, important security vulnerabilities are discovered in software
32896 packages and must be patched. Guix developers try hard to keep track of
32897 known vulnerabilities and to apply fixes as soon as possible in the
32898 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
32899 containing only security updates). The @command{guix lint} tool helps
32900 developers find out about vulnerable versions of software packages in the
32905 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
32906 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
32907 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
32911 @xref{Invoking guix lint}, for more information.
32913 Guix follows a functional
32914 package management discipline (@pxref{Introduction}), which implies
32915 that, when a package is changed, @emph{every package that depends on it}
32916 must be rebuilt. This can significantly slow down the deployment of
32917 fixes in core packages such as libc or Bash, since basically the whole
32918 distribution would need to be rebuilt. Using pre-built binaries helps
32919 (@pxref{Substitutes}), but deployment may still take more time than
32923 To address this, Guix implements @dfn{grafts}, a mechanism that allows
32924 for fast deployment of critical updates without the costs associated
32925 with a whole-distribution rebuild. The idea is to rebuild only the
32926 package that needs to be patched, and then to ``graft'' it onto packages
32927 explicitly installed by the user and that were previously referring to
32928 the original package. The cost of grafting is typically very low, and
32929 order of magnitudes lower than a full rebuild of the dependency chain.
32931 @cindex replacements of packages, for grafts
32932 For instance, suppose a security update needs to be applied to Bash.
32933 Guix developers will provide a package definition for the ``fixed''
32934 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
32935 Packages}). Then, the original package definition is augmented with a
32936 @code{replacement} field pointing to the package containing the bug fix:
32943 (replacement bash-fixed)))
32946 From there on, any package depending directly or indirectly on Bash---as
32947 reported by @command{guix gc --requisites} (@pxref{Invoking guix
32948 gc})---that is installed is automatically ``rewritten'' to refer to
32949 @code{bash-fixed} instead of @code{bash}. This grafting process takes
32950 time proportional to the size of the package, usually less than a
32951 minute for an ``average'' package on a recent machine. Grafting is
32952 recursive: when an indirect dependency requires grafting, then grafting
32953 ``propagates'' up to the package that the user is installing.
32955 Currently, the length of the name and version of the graft and that of
32956 the package it replaces (@code{bash-fixed} and @code{bash} in the example
32957 above) must be equal. This restriction mostly comes from the fact that
32958 grafting works by patching files, including binary files, directly.
32959 Other restrictions may apply: for instance, when adding a graft to a
32960 package providing a shared library, the original shared library and its
32961 replacement must have the same @code{SONAME} and be binary-compatible.
32963 The @option{--no-grafts} command-line option allows you to forcefully
32964 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
32968 guix build bash --no-grafts
32972 returns the store file name of the original Bash, whereas:
32979 returns the store file name of the ``fixed'', replacement Bash. This
32980 allows you to distinguish between the two variants of Bash.
32982 To verify which Bash your whole profile refers to, you can run
32983 (@pxref{Invoking guix gc}):
32986 guix gc -R `readlink -f ~/.guix-profile` | grep bash
32990 @dots{} and compare the store file names that you get with those above.
32991 Likewise for a complete Guix system generation:
32994 guix gc -R `guix system build my-config.scm` | grep bash
32997 Lastly, to check which Bash running processes are using, you can use the
32998 @command{lsof} command:
33001 lsof | grep /gnu/store/.*bash
33005 @node Bootstrapping
33006 @chapter Bootstrapping
33008 @c Adapted from the ELS 2013 paper.
33010 @cindex bootstrapping
33012 Bootstrapping in our context refers to how the distribution gets built
33013 ``from nothing''. Remember that the build environment of a derivation
33014 contains nothing but its declared inputs (@pxref{Introduction}). So
33015 there's an obvious chicken-and-egg problem: how does the first package
33016 get built? How does the first compiler get compiled?
33018 It is tempting to think of this question as one that only die-hard
33019 hackers may care about. However, while the answer to that question is
33020 technical in nature, its implications are wide-ranging. How the
33021 distribution is bootstrapped defines the extent to which we, as
33022 individuals and as a collective of users and hackers, can trust the
33023 software we run. It is a central concern from the standpoint of
33024 @emph{security} and from a @emph{user freedom} viewpoint.
33026 @cindex bootstrap binaries
33027 The GNU system is primarily made of C code, with libc at its core. The
33028 GNU build system itself assumes the availability of a Bourne shell and
33029 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
33030 `grep'. Furthermore, build programs---programs that run
33031 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
33032 (@pxref{Derivations}). Consequently, to be able to build anything at
33033 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
33034 Binutils, libc, and the other packages mentioned above---the
33035 @dfn{bootstrap binaries}.
33037 These bootstrap binaries are ``taken for granted'', though we can also
33038 re-create them if needed (@pxref{Preparing to Use the Bootstrap
33042 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
33043 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
33046 @node Reduced Binary Seed Bootstrap
33047 @section The Reduced Binary Seed Bootstrap
33049 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
33050 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
33051 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
33052 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
33053 ``taken for granted.''
33055 Taking the bootstrap binaries for granted means that we consider them to
33056 be a correct and trustworthy ``seed'' for building the complete system.
33057 Therein lies a problem: the combined size of these bootstrap binaries is
33058 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
33059 or even inspecting these is next to impossible.
33061 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
33062 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
33063 Source Bootstrap'' and while we are working towards that goal it would
33064 be hyperbole to use that term for what we do now.}.
33066 The Reduced Binary Seed bootstrap removes the most critical tools---from a
33067 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
33068 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
33069 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
33070 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
33072 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
33073 C Library are built from source. From here on the more traditional
33074 bootstrap process resumes. This approach has reduced the bootstrap
33075 binaries in size to about 145MB in Guix v1.1.
33077 The next step that Guix has taken is to replace the shell and all its
33078 utilities with implementations in Guile Scheme, the @emph{Scheme-only
33079 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
33080 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
33081 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
33082 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
33083 removed are now built from source.
33085 Building the GNU System from source is currently only possibly by adding
33086 some historical GNU packages as intermediate steps@footnote{Packages
33087 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
33088 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
33089 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
33090 and GNU packages become more bootstrappable again (e.g., new releases of
33091 GNU Sed will also ship as gzipped tarballs again, as alternative to the
33092 hard to bootstrap @code{xz}-compression), this set of added packages can
33093 hopefully be reduced again.
33095 The graph below shows the resulting dependency graph for
33096 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
33097 traditional bootstrap of the rest of the Guix System.
33099 @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
33100 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
33102 The only significant binary bootstrap seeds that remain@footnote{
33103 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
33104 together with @code{mes}.} are a Scheme intepreter and a Scheme
33105 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
33106 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
33107 to get Guile running.}.
33109 This further reduction has brought down the size of the binary seed to
33110 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
33112 Work is ongoing to remove all binary blobs from our free software
33113 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
33114 is work to bring these bootstraps to the @code{arm-linux} and
33115 @code{aarch64-linux} architectures and to the Hurd.
33117 If you are interested, join us on @samp{#bootstrappable} on the Freenode
33118 IRC network or discuss on @email{bug-mes@@gnu.org} or
33119 @email{gash-devel@@nongnu.org}.
33121 @node Preparing to Use the Bootstrap Binaries
33122 @section Preparing to Use the Bootstrap Binaries
33124 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
33125 @c large image, it's hard to scroll. Oh well.
33126 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
33128 The figure above shows the very beginning of the dependency graph of the
33129 distribution, corresponding to the package definitions of the @code{(gnu
33130 packages bootstrap)} module. A similar figure can be generated with
33131 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
33134 guix graph -t derivation \
33135 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
33136 | dot -Tps > gcc.ps
33139 or, for the further Reduced Binary Seed bootstrap
33142 guix graph -t derivation \
33143 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
33144 | dot -Tps > mes.ps
33147 At this level of detail, things are
33148 slightly complex. First, Guile itself consists of an ELF executable,
33149 along with many source and compiled Scheme files that are dynamically
33150 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
33151 tarball shown in this graph. This tarball is part of Guix's ``source''
33152 distribution, and gets inserted into the store with @code{add-to-store}
33153 (@pxref{The Store}).
33155 But how do we write a derivation that unpacks this tarball and adds it
33156 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
33157 derivation---the first one that gets built---uses @code{bash} as its
33158 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
33159 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
33160 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
33161 the Guix source distribution, whose sole purpose is to allow the Guile
33162 tarball to be unpacked.
33164 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
33165 Guile that can be used to run subsequent build programs. Its first task
33166 is to download tarballs containing the other pre-built binaries---this
33167 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
33168 @code{ftp-client.scm} are used for this purpose. The
33169 @code{module-import.drv} derivations import those modules in a directory
33170 in the store, using the original layout. The
33171 @code{module-import-compiled.drv} derivations compile those modules, and
33172 write them in an output directory with the right layout. This
33173 corresponds to the @code{#:modules} argument of
33174 @code{build-expression->derivation} (@pxref{Derivations}).
33176 Finally, the various tarballs are unpacked by the derivations
33177 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
33178 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
33179 point we have a working C tool chain.
33181 @unnumberedsec Building the Build Tools
33183 Bootstrapping is complete when we have a full tool chain that does not
33184 depend on the pre-built bootstrap tools discussed above. This
33185 no-dependency requirement is verified by checking whether the files of
33186 the final tool chain contain references to the @file{/gnu/store}
33187 directories of the bootstrap inputs. The process that leads to this
33188 ``final'' tool chain is described by the package definitions found in
33189 the @code{(gnu packages commencement)} module.
33191 The @command{guix graph} command allows us to ``zoom out'' compared to
33192 the graph above, by looking at the level of package objects instead of
33193 individual derivations---remember that a package may translate to
33194 several derivations, typically one derivation to download its source,
33195 one to build the Guile modules it needs, and one to actually build the
33196 package from source. The command:
33199 guix graph -t bag \
33200 -e '(@@@@ (gnu packages commencement)
33201 glibc-final-with-bootstrap-bash)' | xdot -
33205 displays the dependency graph leading to the ``final'' C
33206 library@footnote{You may notice the @code{glibc-intermediate} label,
33207 suggesting that it is not @emph{quite} final, but as a good
33208 approximation, we will consider it final.}, depicted below.
33210 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
33212 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
33213 The first tool that gets built with the bootstrap binaries is
33214 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
33215 for all the following packages. From there Findutils and Diffutils get
33218 Then come the first-stage Binutils and GCC, built as pseudo cross
33219 tools---i.e., with @option{--target} equal to @option{--host}. They are
33220 used to build libc. Thanks to this cross-build trick, this libc is
33221 guaranteed not to hold any reference to the initial tool chain.
33223 From there the final Binutils and GCC (not shown above) are built. GCC
33224 uses @command{ld} from the final Binutils, and links programs against
33225 the just-built libc. This tool chain is used to build the other
33226 packages used by Guix and by the GNU Build System: Guile, Bash,
33229 And voilà! At this point we have the complete set of build tools that
33230 the GNU Build System expects. These are in the @code{%final-inputs}
33231 variable of the @code{(gnu packages commencement)} module, and are
33232 implicitly used by any package that uses @code{gnu-build-system}
33233 (@pxref{Build Systems, @code{gnu-build-system}}).
33236 @unnumberedsec Building the Bootstrap Binaries
33238 @cindex bootstrap binaries
33239 Because the final tool chain does not depend on the bootstrap binaries,
33240 those rarely need to be updated. Nevertheless, it is useful to have an
33241 automated way to produce them, should an update occur, and this is what
33242 the @code{(gnu packages make-bootstrap)} module provides.
33244 The following command builds the tarballs containing the bootstrap binaries
33245 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
33246 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
33247 and Guile, and a tarball containing a mixture of Coreutils and other basic
33248 command-line tools):
33251 guix build bootstrap-tarballs
33254 The generated tarballs are those that should be referred to in the
33255 @code{(gnu packages bootstrap)} module mentioned at the beginning of
33258 Still here? Then perhaps by now you've started to wonder: when do we
33259 reach a fixed point? That is an interesting question! The answer is
33260 unknown, but if you would like to investigate further (and have
33261 significant computational and storage resources to do so), then let us
33264 @unnumberedsec Reducing the Set of Bootstrap Binaries
33266 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
33267 binary code! Why is that a problem? It's a problem because these big chunks
33268 of binary code are practically non-auditable, which makes it hard to establish
33269 what source code produced them. Every unauditable binary also leaves us
33270 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
33271 paper @emph{Reflections on Trusting Trust}.
33273 This is mitigated by the fact that our bootstrap binaries were generated
33274 from an earlier Guix revision. Nevertheless it lacks the level of
33275 transparency that we get in the rest of the package dependency graph,
33276 where Guix always gives us a source-to-binary mapping. Thus, our goal
33277 is to reduce the set of bootstrap binaries to the bare minimum.
33279 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
33280 on-going projects to do that. One of these is about replacing the
33281 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
33282 of increasing complexity, which could be built from source starting from
33283 a simple and auditable assembler.
33285 Our first major achievement is the replacement of of GCC, the GNU C Library
33286 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
33287 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
33288 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
33289 bootstrapped yet and thus we inject them as binary seeds. We call this the
33290 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
33291 binaries! Also, it has eliminated the C compiler binary; i686-linux and
33292 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
33294 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
33295 also looking at any other bootstrap binaries. Your help is welcome!
33298 @chapter Porting to a New Platform
33300 As discussed above, the GNU distribution is self-contained, and
33301 self-containment is achieved by relying on pre-built ``bootstrap
33302 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
33303 operating system kernel, CPU architecture, and application binary
33304 interface (ABI). Thus, to port the distribution to a platform that is
33305 not yet supported, one must build those bootstrap binaries, and update
33306 the @code{(gnu packages bootstrap)} module to use them on that platform.
33308 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
33309 When everything goes well, and assuming the GNU tool chain supports the
33310 target platform, this can be as simple as running a command like this
33314 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
33317 For this to work, the @code{glibc-dynamic-linker} procedure in
33318 @code{(gnu packages bootstrap)} must be augmented to return the right
33319 file name for libc's dynamic linker on that platform; likewise,
33320 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
33321 taught about the new platform.
33323 Once these are built, the @code{(gnu packages bootstrap)} module needs
33324 to be updated to refer to these binaries on the target platform. That
33325 is, the hashes and URLs of the bootstrap tarballs for the new platform
33326 must be added alongside those of the currently supported platforms. The
33327 bootstrap Guile tarball is treated specially: it is expected to be
33328 available locally, and @file{gnu/local.mk} has rules to download it for
33329 the supported architectures; a rule for the new platform must be added
33332 In practice, there may be some complications. First, it may be that the
33333 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
33334 above) is not recognized by all the GNU tools. Typically, glibc
33335 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
33336 configure flag (see @code{gcc.scm} for examples of how to handle this).
33337 Second, some of the required packages could fail to build for that
33338 platform. Lastly, the generated binaries could be broken for some
33341 @c *********************************************************************
33342 @include contributing.texi
33344 @c *********************************************************************
33345 @node Acknowledgments
33346 @chapter Acknowledgments
33348 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
33349 which was designed and
33350 implemented by Eelco Dolstra, with contributions from other people (see
33351 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
33352 management, and promoted unprecedented features, such as transactional
33353 package upgrades and rollbacks, per-user profiles, and referentially
33354 transparent build processes. Without this work, Guix would not exist.
33356 The Nix-based software distributions, Nixpkgs and NixOS, have also been
33357 an inspiration for Guix.
33359 GNU@tie{}Guix itself is a collective work with contributions from a
33360 number of people. See the @file{AUTHORS} file in Guix for more
33361 information on these fine people. The @file{THANKS} file lists people
33362 who have helped by reporting bugs, taking care of the infrastructure,
33363 providing artwork and themes, making suggestions, and more---thank you!
33366 @c *********************************************************************
33367 @node GNU Free Documentation License
33368 @appendix GNU Free Documentation License
33369 @cindex license, GNU Free Documentation License
33370 @include fdl-1.3.texi
33372 @c *********************************************************************
33373 @node Concept Index
33374 @unnumbered Concept Index
33377 @node Programming Index
33378 @unnumbered Programming Index
33379 @syncodeindex tp fn
33380 @syncodeindex vr fn
33385 @c Local Variables:
33386 @c ispell-local-dictionary: "american";