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, 2021 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, 2021 Chris Marusich@*
35 Copyright @copyright{} 2016, 2017, 2018, 2019, 2020, 2021 Efraim Flashner@*
36 Copyright @copyright{} 2016 John Darrington@*
37 Copyright @copyright{} 2016, 2017 Nikita Gillmann@*
38 Copyright @copyright{} 2016, 2017, 2018, 2019, 2020 Jan Nieuwenhuizen@*
39 Copyright @copyright{} 2016, 2017, 2018, 2019, 2020 Julien Lepiller@*
40 Copyright @copyright{} 2016 Alex ter Weele@*
41 Copyright @copyright{} 2016, 2017, 2018, 2019 Christopher Baines@*
42 Copyright @copyright{} 2017, 2018, 2019 Clément Lassieur@*
43 Copyright @copyright{} 2017, 2018, 2020, 2021 Mathieu Othacehe@*
44 Copyright @copyright{} 2017 Federico Beffa@*
45 Copyright @copyright{} 2017, 2018 Carlo Zancanaro@*
46 Copyright @copyright{} 2017 Thomas Danckaert@*
47 Copyright @copyright{} 2017 humanitiesNerd@*
48 Copyright @copyright{} 2017, 2021 Christopher Lemmer Webber@*
49 Copyright @copyright{} 2017, 2018, 2019, 2020 Marius Bakke@*
50 Copyright @copyright{} 2017, 2019, 2020 Hartmut Goebel@*
51 Copyright @copyright{} 2017, 2019, 2020, 2021 Maxim Cournoyer@*
52 Copyright @copyright{} 2017, 2018, 2019, 2020, 2021 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, 2021 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@*
89 Copyright @copyright{} 2020 Edgar Vincent@*
91 Permission is granted to copy, distribute and/or modify this document
92 under the terms of the GNU Free Documentation License, Version 1.3 or
93 any later version published by the Free Software Foundation; with no
94 Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A
95 copy of the license is included in the section entitled ``GNU Free
96 Documentation License''.
99 @dircategory System administration
101 * Guix: (guix). Manage installed software and system configuration.
102 * guix package: (guix)Invoking guix package. Installing, removing, and upgrading packages.
103 * guix gc: (guix)Invoking guix gc. Reclaiming unused disk space.
104 * guix pull: (guix)Invoking guix pull. Update the list of available packages.
105 * guix system: (guix)Invoking guix system. Manage the operating system configuration.
106 * guix deploy: (guix)Invoking guix deploy. Manage operating system configurations for remote hosts.
109 @dircategory Software development
111 * guix environment: (guix)Invoking guix environment. Building development environments with Guix.
112 * guix build: (guix)Invoking guix build. Building packages.
113 * guix pack: (guix)Invoking guix pack. Creating binary bundles.
117 @title GNU Guix Reference Manual
118 @subtitle Using the GNU Guix Functional Package Manager
119 @author The GNU Guix Developers
122 @vskip 0pt plus 1filll
123 Edition @value{EDITION} @*
131 @c *********************************************************************
135 This document describes GNU Guix version @value{VERSION}, a functional
136 package management tool written for the GNU system.
138 @c TRANSLATORS: You can replace the following paragraph with information on
139 @c how to join your own translation team and how to report issues with the
141 This manual is also available in Simplified Chinese (@pxref{Top,,, guix.zh_CN,
142 GNU Guix参考手册}), French (@pxref{Top,,, guix.fr, Manuel de référence de GNU
143 Guix}), German (@pxref{Top,,, guix.de, Referenzhandbuch zu GNU Guix}),
144 Spanish (@pxref{Top,,, guix.es, Manual de referencia de GNU Guix}), and
145 Russian (@pxref{Top,,, guix.ru, Руководство GNU Guix}). If you
146 would like to translate it in your native language, consider joining
147 @uref{https://translate.fedoraproject.org/projects/guix/documentation-manual,
151 * Introduction:: What is Guix about?
152 * Installation:: Installing Guix.
153 * System Installation:: Installing the whole operating system.
154 * Getting Started:: Your first steps.
155 * Package Management:: Package installation, upgrade, etc.
156 * Channels:: Customizing the package collection.
157 * Development:: Guix-aided software development.
158 * Programming Interface:: Using Guix in Scheme.
159 * Utilities:: Package management commands.
160 * System Configuration:: Configuring the operating system.
161 * Documentation:: Browsing software user manuals.
162 * Installing Debugging Files:: Feeding the debugger.
163 * Security Updates:: Deploying security fixes quickly.
164 * Bootstrapping:: GNU/Linux built from scratch.
165 * Porting:: Targeting another platform or kernel.
166 * Contributing:: Your help needed!
168 * Acknowledgments:: Thanks!
169 * GNU Free Documentation License:: The license of this manual.
170 * Concept Index:: Concepts.
171 * Programming Index:: Data types, functions, and variables.
174 --- The Detailed Node Listing ---
178 * Managing Software the Guix Way:: What's special.
179 * GNU Distribution:: The packages and tools.
183 * Binary Installation:: Getting Guix running in no time!
184 * Requirements:: Software needed to build and run Guix.
185 * Running the Test Suite:: Testing Guix.
186 * Setting Up the Daemon:: Preparing the build daemon's environment.
187 * Invoking guix-daemon:: Running the build daemon.
188 * Application Setup:: Application-specific setup.
189 * Upgrading Guix:: Upgrading Guix and its build daemon.
191 Setting Up the Daemon
193 * Build Environment Setup:: Preparing the isolated build environment.
194 * Daemon Offload Setup:: Offloading builds to remote machines.
195 * SELinux Support:: Using an SELinux policy for the daemon.
199 * Limitations:: What you can expect.
200 * Hardware Considerations:: Supported hardware.
201 * USB Stick and DVD Installation:: Preparing the installation medium.
202 * Preparing for Installation:: Networking, partitioning, etc.
203 * Guided Graphical Installation:: Easy graphical installation.
204 * Manual Installation:: Manual installation for wizards.
205 * After System Installation:: When installation succeeded.
206 * Installing Guix in a VM:: Guix System playground.
207 * Building the Installation Image:: How this comes to be.
211 * Keyboard Layout and Networking and Partitioning:: Initial setup.
212 * Proceeding with the Installation:: Installing.
216 * Features:: How Guix will make your life brighter.
217 * Invoking guix package:: Package installation, removal, etc.
218 * Substitutes:: Downloading pre-built binaries.
219 * Packages with Multiple Outputs:: Single source package, multiple outputs.
220 * Invoking guix gc:: Running the garbage collector.
221 * Invoking guix pull:: Fetching the latest Guix and distribution.
222 * Invoking guix time-machine:: Running an older revision of Guix.
223 * Inferiors:: Interacting with another revision of Guix.
224 * Invoking guix describe:: Display information about your Guix revision.
225 * Invoking guix archive:: Exporting and importing store files.
229 * Official Substitute Server:: One particular source of substitutes.
230 * Substitute Server Authorization:: How to enable or disable substitutes.
231 * Getting Substitutes from Other Servers:: Substitute diversity.
232 * Substitute Authentication:: How Guix verifies substitutes.
233 * Proxy Settings:: How to get substitutes via proxy.
234 * Substitution Failure:: What happens when substitution fails.
235 * On Trusting Binaries:: How can you trust that binary blob?
239 * Specifying Additional Channels:: Extending the package collection.
240 * Using a Custom Guix Channel:: Using a customized Guix.
241 * Replicating Guix:: Running the @emph{exact same} Guix.
242 * Channel Authentication:: How Guix verifies what it fetches.
243 * Channels with Substitutes:: Using channels with available substitutes.
244 * Creating a Channel:: How to write your custom channel.
245 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
246 * Declaring Channel Dependencies:: How to depend on other channels.
247 * Specifying Channel Authorizations:: Defining channel authors authorizations.
248 * Primary URL:: Distinguishing mirror to original.
249 * Writing Channel News:: Communicating information to channel's users.
253 * Invoking guix environment:: Setting up development environments.
254 * Invoking guix pack:: Creating software bundles.
255 * The GCC toolchain:: Working with languages supported by GCC.
256 * Invoking guix git authenticate:: Authenticating Git repositories.
258 Programming Interface
260 * Package Modules:: Packages from the programmer's viewpoint.
261 * Defining Packages:: Defining new packages.
262 * Defining Package Variants:: Customizing packages.
263 * Build Systems:: Specifying how packages are built.
264 * Build Phases:: Phases of the build process of a package.
265 * Build Utilities:: Helpers for your package definitions and more.
266 * The Store:: Manipulating the package store.
267 * Derivations:: Low-level interface to package derivations.
268 * The Store Monad:: Purely functional interface to the store.
269 * G-Expressions:: Manipulating build expressions.
270 * Invoking guix repl:: Programming Guix in Guile.
274 * package Reference:: The package data type.
275 * origin Reference:: The origin data type.
279 * Invoking guix build:: Building packages from the command line.
280 * Invoking guix edit:: Editing package definitions.
281 * Invoking guix download:: Downloading a file and printing its hash.
282 * Invoking guix hash:: Computing the cryptographic hash of a file.
283 * Invoking guix import:: Importing package definitions.
284 * Invoking guix refresh:: Updating package definitions.
285 * Invoking guix lint:: Finding errors in package definitions.
286 * Invoking guix size:: Profiling disk usage.
287 * Invoking guix graph:: Visualizing the graph of packages.
288 * Invoking guix publish:: Sharing substitutes.
289 * Invoking guix challenge:: Challenging substitute servers.
290 * Invoking guix copy:: Copying to and from a remote store.
291 * Invoking guix container:: Process isolation.
292 * Invoking guix weather:: Assessing substitute availability.
293 * Invoking guix processes:: Listing client processes.
295 Invoking @command{guix build}
297 * Common Build Options:: Build options for most commands.
298 * Package Transformation Options:: Creating variants of packages.
299 * Additional Build Options:: Options specific to 'guix build'.
300 * Debugging Build Failures:: Real life packaging experience.
304 * Using the Configuration System:: Customizing your GNU system.
305 * operating-system Reference:: Detail of operating-system declarations.
306 * File Systems:: Configuring file system mounts.
307 * Mapped Devices:: Block device extra processing.
308 * User Accounts:: Specifying user accounts.
309 * Keyboard Layout:: How the system interprets key strokes.
310 * Locales:: Language and cultural convention settings.
311 * Services:: Specifying system services.
312 * Setuid Programs:: Programs running with root privileges.
313 * X.509 Certificates:: Authenticating HTTPS servers.
314 * Name Service Switch:: Configuring libc's name service switch.
315 * Initial RAM Disk:: Linux-Libre bootstrapping.
316 * Bootloader Configuration:: Configuring the boot loader.
317 * Invoking guix system:: Instantiating a system configuration.
318 * Invoking guix deploy:: Deploying a system configuration to a remote host.
319 * Running Guix in a VM:: How to run Guix System in a virtual machine.
320 * Defining Services:: Adding new service definitions.
324 * Base Services:: Essential system services.
325 * Scheduled Job Execution:: The mcron service.
326 * Log Rotation:: The rottlog service.
327 * Networking Services:: Network setup, SSH daemon, etc.
328 * Unattended Upgrades:: Automated system upgrades.
329 * X Window:: Graphical display.
330 * Printing Services:: Local and remote printer support.
331 * Desktop Services:: D-Bus and desktop services.
332 * Sound Services:: ALSA and Pulseaudio services.
333 * Database Services:: SQL databases, key-value stores, etc.
334 * Mail Services:: IMAP, POP3, SMTP, and all that.
335 * Messaging Services:: Messaging services.
336 * Telephony Services:: Telephony services.
337 * Monitoring Services:: Monitoring services.
338 * Kerberos Services:: Kerberos services.
339 * LDAP Services:: LDAP services.
340 * Web Services:: Web servers.
341 * Certificate Services:: TLS certificates via Let's Encrypt.
342 * DNS Services:: DNS daemons.
343 * VPN Services:: VPN daemons.
344 * Network File System:: NFS related services.
345 * Continuous Integration:: The Cuirass service.
346 * Power Management Services:: Extending battery life.
347 * Audio Services:: The MPD.
348 * Virtualization Services:: Virtualization services.
349 * Version Control Services:: Providing remote access to Git repositories.
350 * Game Services:: Game servers.
351 * PAM Mount Service:: Service to mount volumes when logging in.
352 * Guix Services:: Services relating specifically to Guix.
353 * Linux Services:: Services tied to the Linux kernel.
354 * Hurd Services:: Services specific for a Hurd System.
355 * Miscellaneous Services:: Other services.
359 * Service Composition:: The model for composing services.
360 * Service Types and Services:: Types and services.
361 * Service Reference:: API reference.
362 * Shepherd Services:: A particular type of service.
364 Installing Debugging Files
366 * Separate Debug Info:: Installing 'debug' outputs.
367 * Rebuilding Debug Info:: Building missing debug info.
371 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
372 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
377 @c *********************************************************************
379 @chapter Introduction
382 GNU Guix@footnote{``Guix'' is pronounced like ``geeks'', or ``ɡiːks''
383 using the international phonetic alphabet (IPA).} is a package
384 management tool for and distribution of the GNU system.
385 Guix makes it easy for unprivileged
386 users to install, upgrade, or remove software packages, to roll back to a
387 previous package set, to build packages from source, and generally
388 assists with the creation and maintenance of software environments.
391 @cindex GuixSD, now Guix System
392 @cindex Guix System Distribution, now Guix System
393 You can install GNU@tie{}Guix on top of an existing GNU/Linux system where it
394 complements the available tools without interference (@pxref{Installation}),
395 or you can use it as a standalone operating system distribution,
396 @dfn{Guix@tie{}System}@footnote{We used to refer to Guix System as ``Guix
397 System Distribution'' or ``GuixSD''. We now consider it makes more sense to
398 group everything under the ``Guix'' banner since, after all, Guix System is
399 readily available through the @command{guix system} command, even if you're
400 using a different distro underneath!}. @xref{GNU Distribution}.
403 * Managing Software the Guix Way:: What's special.
404 * GNU Distribution:: The packages and tools.
407 @node Managing Software the Guix Way
408 @section Managing Software the Guix Way
410 @cindex user interfaces
411 Guix provides a command-line package management interface
412 (@pxref{Package Management}), tools to help with software development
413 (@pxref{Development}), command-line utilities for more advanced usage
414 (@pxref{Utilities}), as well as Scheme programming interfaces
415 (@pxref{Programming Interface}).
417 Its @dfn{build daemon} is responsible for building packages on behalf of
418 users (@pxref{Setting Up the Daemon}) and for downloading pre-built
419 binaries from authorized sources (@pxref{Substitutes}).
421 @cindex extensibility of the distribution
422 @cindex customization, of packages
423 Guix includes package definitions for many GNU and non-GNU packages, all
424 of which @uref{https://www.gnu.org/philosophy/free-sw.html, respect the
425 user's computing freedom}. It is @emph{extensible}: users can write
426 their own package definitions (@pxref{Defining Packages}) and make them
427 available as independent package modules (@pxref{Package Modules}). It
428 is also @emph{customizable}: users can @emph{derive} specialized package
429 definitions from existing ones, including from the command line
430 (@pxref{Package Transformation Options}).
432 @cindex functional package management
434 Under the hood, Guix implements the @dfn{functional package management}
435 discipline pioneered by Nix (@pxref{Acknowledgments}).
436 In Guix, the package build and installation process is seen
437 as a @emph{function}, in the mathematical sense. That function takes inputs,
438 such as build scripts, a compiler, and libraries, and
439 returns an installed package. As a pure function, its result depends
440 solely on its inputs---for instance, it cannot refer to software or
441 scripts that were not explicitly passed as inputs. A build function
442 always produces the same result when passed a given set of inputs. It
443 cannot alter the environment of the running system in
444 any way; for instance, it cannot create, modify, or delete files outside
445 of its build and installation directories. This is achieved by running
446 build processes in isolated environments (or @dfn{containers}), where only their
447 explicit inputs are visible.
450 The result of package build functions is @dfn{cached} in the file
451 system, in a special directory called @dfn{the store} (@pxref{The
452 Store}). Each package is installed in a directory of its own in the
453 store---by default under @file{/gnu/store}. The directory name contains
454 a hash of all the inputs used to build that package; thus, changing an
455 input yields a different directory name.
457 This approach is the foundation for the salient features of Guix: support
458 for transactional package upgrade and rollback, per-user installation, and
459 garbage collection of packages (@pxref{Features}).
462 @node GNU Distribution
463 @section GNU Distribution
466 Guix comes with a distribution of the GNU system consisting entirely of
467 free software@footnote{The term ``free'' here refers to the
468 @url{https://www.gnu.org/philosophy/free-sw.html,freedom provided to
469 users of that software}.}. The
470 distribution can be installed on its own (@pxref{System Installation}),
471 but it is also possible to install Guix as a package manager on top of
472 an installed GNU/Linux system (@pxref{Installation}). When we need to
473 distinguish between the two, we refer to the standalone distribution as
476 The distribution provides core GNU packages such as GNU libc, GCC, and
477 Binutils, as well as many GNU and non-GNU applications. The complete
478 list of available packages can be browsed
479 @url{https://www.gnu.org/software/guix/packages,on-line} or by
480 running @command{guix package} (@pxref{Invoking guix package}):
483 guix package --list-available
486 Our goal is to provide a practical 100% free software distribution of
487 Linux-based and other variants of GNU, with a focus on the promotion and
488 tight integration of GNU components, and an emphasis on programs and
489 tools that help users exert that freedom.
491 Packages are currently available on the following platforms:
496 Intel/AMD @code{x86_64} architecture, Linux-Libre kernel.
499 Intel 32-bit architecture (IA32), Linux-Libre kernel.
502 ARMv7-A architecture with hard float, Thumb-2 and NEON,
503 using the EABI hard-float application binary interface (ABI),
504 and Linux-Libre kernel.
507 little-endian 64-bit ARMv8-A processors, Linux-Libre kernel.
510 @uref{https://hurd.gnu.org, GNU/Hurd} on the Intel 32-bit architecture
513 This configuration is experimental and under development. The easiest
514 way for you to give it a try is by setting up an instance of
515 @code{hurd-vm-service-type} on your GNU/Linux machine
516 (@pxref{transparent-emulation-qemu, @code{hurd-vm-service-type}}).
517 @xref{Contributing}, on how to help!
519 @item mips64el-linux (deprecated)
520 little-endian 64-bit MIPS processors, specifically the Loongson series,
521 n32 ABI, and Linux-Libre kernel. This configuration is no longer fully
522 supported; in particular, there is no ongoing work to ensure that this
523 architecture still works. Should someone decide they wish to revive this
524 architecture then the code is still available.
526 @item powerpc64le-linux
527 little-endian 64-bit Power ISA processors, Linux-Libre kernel. This
528 includes POWER9 systems such as the
529 @uref{https://www.fsf.org/news/talos-ii-mainboard-and-talos-ii-lite-mainboard-now-fsf-certified-to-respect-your-freedom,
530 RYF Talos II mainboard}. This platform is available as a "technology
531 preview": although it is supported, substitutes are not yet available
532 from the build farm (@pxref{Substitutes}), and some packages may fail to
533 build (@pxref{Tracking Bugs and Patches}). That said, the Guix
534 community is actively working on improving this support, and now is a
535 great time to try it and get involved!
539 With Guix@tie{}System, you @emph{declare} all aspects of the operating system
540 configuration and Guix takes care of instantiating the configuration in a
541 transactional, reproducible, and stateless fashion (@pxref{System
542 Configuration}). Guix System uses the Linux-libre kernel, the Shepherd
543 initialization system (@pxref{Introduction,,, shepherd, The GNU Shepherd
544 Manual}), the well-known GNU utilities and tool chain, as well as the
545 graphical environment or system services of your choice.
547 Guix System is available on all the above platforms except
548 @code{mips64el-linux} and @code{powerpc64le-linux}.
551 For information on porting to other architectures or kernels,
554 Building this distribution is a cooperative effort, and you are invited
555 to join! @xref{Contributing}, for information about how you can help.
558 @c *********************************************************************
560 @chapter Installation
562 @cindex installing Guix
565 We recommend the use of this
566 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
567 shell installer script} to install Guix on top of a running GNU/Linux system,
568 thereafter called a @dfn{foreign distro}.@footnote{This section is concerned
569 with the installation of the package manager, which can be done on top of a
570 running GNU/Linux system. If, instead, you want to install the complete GNU
571 operating system, @pxref{System Installation}.} The script automates the
572 download, installation, and initial configuration of Guix. It should be run
576 @cindex foreign distro
577 @cindex directories related to foreign distro
578 When installed on a foreign distro, GNU@tie{}Guix complements the available
579 tools without interference. Its data lives exclusively in two directories,
580 usually @file{/gnu/store} and @file{/var/guix}; other files on your system,
581 such as @file{/etc}, are left untouched.
583 Once installed, Guix can be updated by running @command{guix pull}
584 (@pxref{Invoking guix pull}).
586 If you prefer to perform the installation steps manually or want to tweak
587 them, you may find the following subsections useful. They describe the
588 software requirements of Guix, as well as how to install it manually and get
592 * Binary Installation:: Getting Guix running in no time!
593 * Requirements:: Software needed to build and run Guix.
594 * Running the Test Suite:: Testing Guix.
595 * Setting Up the Daemon:: Preparing the build daemon's environment.
596 * Invoking guix-daemon:: Running the build daemon.
597 * Application Setup:: Application-specific setup.
598 * Upgrading Guix:: Upgrading Guix and its build daemon.
601 @node Binary Installation
602 @section Binary Installation
604 @cindex installing Guix from binaries
605 @cindex installer script
606 This section describes how to install Guix on an arbitrary system from a
607 self-contained tarball providing binaries for Guix and for all its
608 dependencies. This is often quicker than installing from source, which
609 is described in the next sections. The only requirement is to have
612 @c Note duplicated from the ``Installation'' node.
614 We recommend the use of this
615 @uref{https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh,
616 shell installer script}. The script automates the download, installation, and
617 initial configuration steps described below. It should be run as the root
618 user. As root, you can thus run this:
622 wget https://git.savannah.gnu.org/cgit/guix.git/plain/etc/guix-install.sh
623 chmod +x guix-install.sh
627 When you're done, @pxref{Application Setup} for extra configuration you
628 might need, and @ref{Getting Started} for your first steps!
631 Installing goes along these lines:
635 @cindex downloading Guix binary
636 Download the binary tarball from
637 @indicateurl{@value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz},
638 where @code{x86_64-linux} can be replaced with @code{i686-linux} for an
639 @code{i686} (32-bits) machine already running the kernel Linux, and so on
640 (@pxref{GNU Distribution}).
642 @c The following is somewhat duplicated in ``System Installation''.
643 Make sure to download the associated @file{.sig} file and to verify the
644 authenticity of the tarball against it, along these lines:
647 $ wget @value{BASE-URL}/guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
648 $ gpg --verify guix-binary-@value{VERSION}.x86_64-linux.tar.xz.sig
651 If that command fails because you do not have the required public key,
652 then run this command to import it:
655 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
656 -qO - | gpg --import -
660 and rerun the @code{gpg --verify} command.
662 Take note that a warning like ``This key is not certified with a trusted
663 signature!'' is normal.
665 @c end authentication part
668 Now, you need to become the @code{root} user. Depending on your distribution,
669 you may have to run @code{su -} or @code{sudo -i}. As @code{root}, run:
673 # tar --warning=no-timestamp -xf \
674 /path/to/guix-binary-@value{VERSION}.x86_64-linux.tar.xz
675 # mv var/guix /var/ && mv gnu /
678 This creates @file{/gnu/store} (@pxref{The Store}) and @file{/var/guix}.
679 The latter contains a ready-to-use profile for @code{root} (see next
682 Do @emph{not} unpack the tarball on a working Guix system since that
683 would overwrite its own essential files.
685 The @option{--warning=no-timestamp} option makes sure GNU@tie{}tar does
686 not emit warnings about ``implausibly old time stamps'' (such
687 warnings were triggered by GNU@tie{}tar 1.26 and older; recent
689 They stem from the fact that all the
690 files in the archive have their modification time set to 1 (which
691 means January 1st, 1970). This is done on purpose to make sure the
692 archive content is independent of its creation time, thus making it
696 Make the profile available under @file{~root/.config/guix/current}, which is
697 where @command{guix pull} will install updates (@pxref{Invoking guix pull}):
700 # mkdir -p ~root/.config/guix
701 # ln -sf /var/guix/profiles/per-user/root/current-guix \
702 ~root/.config/guix/current
705 Source @file{etc/profile} to augment @env{PATH} and other relevant
706 environment variables:
709 # GUIX_PROFILE="`echo ~root`/.config/guix/current" ; \
710 source $GUIX_PROFILE/etc/profile
714 Create the group and user accounts for build users as explained below
715 (@pxref{Build Environment Setup}).
718 Run the daemon, and set it to automatically start on boot.
720 If your host distro uses the systemd init system, this can be achieved
723 @c Versions of systemd that supported symlinked service files are not
724 @c yet widely deployed, so we should suggest that users copy the service
727 @c See this thread for more information:
728 @c https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01199.html
731 # cp ~root/.config/guix/current/lib/systemd/system/gnu-store.mount \
732 ~root/.config/guix/current/lib/systemd/system/guix-daemon.service \
734 # systemctl enable --now gnu-store.mount guix-daemon
737 If your host distro uses the Upstart init system:
740 # initctl reload-configuration
741 # cp ~root/.config/guix/current/lib/upstart/system/guix-daemon.conf \
746 Otherwise, you can still start the daemon manually with:
749 # ~root/.config/guix/current/bin/guix-daemon \
750 --build-users-group=guixbuild
754 Make the @command{guix} command available to other users on the machine,
758 # mkdir -p /usr/local/bin
760 # ln -s /var/guix/profiles/per-user/root/current-guix/bin/guix
763 It is also a good idea to make the Info version of this manual available
767 # mkdir -p /usr/local/share/info
768 # cd /usr/local/share/info
769 # for i in /var/guix/profiles/per-user/root/current-guix/share/info/* ;
773 That way, assuming @file{/usr/local/share/info} is in the search path,
774 running @command{info guix} will open this manual (@pxref{Other Info
775 Directories,,, texinfo, GNU Texinfo}, for more details on changing the
779 @cindex substitutes, authorization thereof
780 To use substitutes from @code{@value{SUBSTITUTE-SERVER}} or one of its mirrors
781 (@pxref{Substitutes}), authorize them:
784 # guix archive --authorize < \
785 ~root/.config/guix/current/share/guix/@value{SUBSTITUTE-SERVER}.pub
789 Each user may need to perform a few additional steps to make their Guix
790 environment ready for use, @pxref{Application Setup}.
793 Voilà, the installation is complete!
795 You can confirm that Guix is working by installing a sample package into
802 The binary installation tarball can be (re)produced and verified simply
803 by running the following command in the Guix source tree:
806 make guix-binary.@var{system}.tar.xz
810 ...@: which, in turn, runs:
813 guix pack -s @var{system} --localstatedir \
814 --profile-name=current-guix guix
817 @xref{Invoking guix pack}, for more info on this handy tool.
820 @section Requirements
822 This section lists requirements when building Guix from source. The
823 build procedure for Guix is the same as for other GNU software, and is
824 not covered here. Please see the files @file{README} and @file{INSTALL}
825 in the Guix source tree for additional details.
827 @cindex official website
828 GNU Guix is available for download from its website at
829 @url{https://www.gnu.org/software/guix/}.
831 GNU Guix depends on the following packages:
834 @item @url{https://gnu.org/software/guile/, GNU Guile}, version 3.0.x or
836 @item @url{https://notabug.org/cwebber/guile-gcrypt, Guile-Gcrypt}, version
839 @uref{https://gnutls.org/, GnuTLS}, specifically its Guile bindings
840 (@pxref{Guile Preparations, how to install the GnuTLS bindings for
841 Guile,, gnutls-guile, GnuTLS-Guile});
843 @uref{https://notabug.org/guile-sqlite3/guile-sqlite3, Guile-SQLite3}, version 0.1.0
845 @item @uref{https://notabug.org/guile-zlib/guile-zlib, Guile-zlib},
846 version 0.1.0 or later;
847 @item @uref{https://notabug.org/guile-lzlib/guile-lzlib, Guile-lzlib};
848 @item @uref{https://www.nongnu.org/guile-avahi/, Guile-Avahi};
850 @c FIXME: Specify a version number once a release has been made.
851 @uref{https://gitlab.com/guile-git/guile-git, Guile-Git}, version 0.3.0
853 @item @uref{https://savannah.nongnu.org/projects/guile-json/, Guile-JSON}
855 @item @url{https://www.gnu.org/software/make/, GNU Make}.
858 The following dependencies are optional:
862 @c Note: We need at least 0.13.0 for #:nodelay.
863 Support for build offloading (@pxref{Daemon Offload Setup}) and
864 @command{guix copy} (@pxref{Invoking guix copy}) depends on
865 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH},
866 version 0.13.0 or later.
869 @uref{https://notabug.org/guile-zstd/guile-zstd, Guile-zstd}, for zstd
870 compression and decompression in @command{guix publish} and for
871 substitutes (@pxref{Invoking guix publish}).
874 @uref{https://ngyro.com/software/guile-semver.html, Guile-Semver} for
875 the @code{crate} importer (@pxref{Invoking guix import}).
878 @uref{https://www.nongnu.org/guile-lib/doc/ref/htmlprag/, Guile-Lib} for
879 the @code{go} importer (@pxref{Invoking guix import}) and for some of
880 the ``updaters'' (@pxref{Invoking guix refresh}).
883 When @url{http://www.bzip.org, libbz2} is available,
884 @command{guix-daemon} can use it to compress build logs.
887 Unless @option{--disable-daemon} was passed to @command{configure}, the
888 following packages are also needed:
891 @item @url{https://gnupg.org/, GNU libgcrypt};
892 @item @url{https://sqlite.org, SQLite 3};
893 @item @url{https://gcc.gnu.org, GCC's g++}, with support for the
897 @cindex state directory
898 When configuring Guix on a system that already has a Guix installation,
899 be sure to specify the same state directory as the existing installation
900 using the @option{--localstatedir} option of the @command{configure}
901 script (@pxref{Directory Variables, @code{localstatedir},, standards,
902 GNU Coding Standards}). Usually, this @var{localstatedir} option is
903 set to the value @file{/var}. The @command{configure} script protects
904 against unintended misconfiguration of @var{localstatedir} so you do not
905 inadvertently corrupt your store (@pxref{The Store}).
907 @node Running the Test Suite
908 @section Running the Test Suite
911 After a successful @command{configure} and @code{make} run, it is a good
912 idea to run the test suite. It can help catch issues with the setup or
913 environment, or bugs in Guix itself---and really, reporting test
914 failures is a good way to help improve the software. To run the test
921 Test cases can run in parallel: you can use the @code{-j} option of
922 GNU@tie{}make to speed things up. The first run may take a few minutes
923 on a recent machine; subsequent runs will be faster because the store
924 that is created for test purposes will already have various things in
927 It is also possible to run a subset of the tests by defining the
928 @code{TESTS} makefile variable as in this example:
931 make check TESTS="tests/store.scm tests/cpio.scm"
934 By default, tests results are displayed at a file level. In order to
935 see the details of every individual test cases, it is possible to define
936 the @code{SCM_LOG_DRIVER_FLAGS} makefile variable as in this example:
939 make check TESTS="tests/base64.scm" SCM_LOG_DRIVER_FLAGS="--brief=no"
942 The underlying SRFI 64 custom Automake test driver used for the 'check'
943 test suite (located at @file{build-aux/test-driver.scm}) also allows
944 selecting which test cases to run at a finer level, via its
945 @option{--select} and @option{--exclude} options. Here's an example, to
946 run all the test cases from the @file{tests/packages.scm} test file
947 whose names start with ``transaction-upgrade-entry'':
950 export SCM_LOG_DRIVER_FLAGS="--select=^transaction-upgrade-entry"
951 make check TESTS="tests/packages.scm"
954 Those wishing to inspect the results of failed tests directly from the
955 command line can add the @option{--errors-only=yes} option to the
956 @code{SCM_LOG_DRIVER_FLAGS} makefile variable and set the @code{VERBOSE}
957 Automake makefile variable, as in:
960 make check SCM_LOG_DRIVER_FLAGS="--brief=no --errors-only=yes" VERBOSE=1
963 The @option{--show-duration=yes} option can be used to print the
964 duration of the individual test cases, when used in combination with
968 make check SCM_LOG_DRIVER_FLAGS="--brief=no --show-duration=yes"
971 @xref{Parallel Test Harness,,,automake,GNU Automake} for more
972 information about the Automake Parallel Test Harness.
974 Upon failure, please email @email{bug-guix@@gnu.org} and attach the
975 @file{test-suite.log} file. Please specify the Guix version being used
976 as well as version numbers of the dependencies (@pxref{Requirements}) in
979 Guix also comes with a whole-system test suite that tests complete
980 Guix System instances. It can only run on systems where
981 Guix is already installed, using:
988 or, again, by defining @code{TESTS} to select a subset of tests to run:
991 make check-system TESTS="basic mcron"
994 These system tests are defined in the @code{(gnu tests @dots{})}
995 modules. They work by running the operating systems under test with
996 lightweight instrumentation in a virtual machine (VM). They can be
997 computationally intensive or rather cheap, depending on whether
998 substitutes are available for their dependencies (@pxref{Substitutes}).
999 Some of them require a lot of storage space to hold VM images.
1001 Again in case of test failures, please send @email{bug-guix@@gnu.org}
1004 @node Setting Up the Daemon
1005 @section Setting Up the Daemon
1008 Operations such as building a package or running the garbage collector
1009 are all performed by a specialized process, the @dfn{build daemon}, on
1010 behalf of clients. Only the daemon may access the store and its
1011 associated database. Thus, any operation that manipulates the store
1012 goes through the daemon. For instance, command-line tools such as
1013 @command{guix package} and @command{guix build} communicate with the
1014 daemon (@i{via} remote procedure calls) to instruct it what to do.
1016 The following sections explain how to prepare the build daemon's
1017 environment. See also @ref{Substitutes}, for information on how to allow
1018 the daemon to download pre-built binaries.
1021 * Build Environment Setup:: Preparing the isolated build environment.
1022 * Daemon Offload Setup:: Offloading builds to remote machines.
1023 * SELinux Support:: Using an SELinux policy for the daemon.
1026 @node Build Environment Setup
1027 @subsection Build Environment Setup
1029 @cindex build environment
1030 In a standard multi-user setup, Guix and its daemon---the
1031 @command{guix-daemon} program---are installed by the system
1032 administrator; @file{/gnu/store} is owned by @code{root} and
1033 @command{guix-daemon} runs as @code{root}. Unprivileged users may use
1034 Guix tools to build packages or otherwise access the store, and the
1035 daemon will do it on their behalf, ensuring that the store is kept in a
1036 consistent state, and allowing built packages to be shared among users.
1039 When @command{guix-daemon} runs as @code{root}, you may not want package
1040 build processes themselves to run as @code{root} too, for obvious
1041 security reasons. To avoid that, a special pool of @dfn{build users}
1042 should be created for use by build processes started by the daemon.
1043 These build users need not have a shell and a home directory: they will
1044 just be used when the daemon drops @code{root} privileges in build
1045 processes. Having several such users allows the daemon to launch
1046 distinct build processes under separate UIDs, which guarantees that they
1047 do not interfere with each other---an essential feature since builds are
1048 regarded as pure functions (@pxref{Introduction}).
1050 On a GNU/Linux system, a build user pool may be created like this (using
1051 Bash syntax and the @code{shadow} commands):
1053 @c See https://lists.gnu.org/archive/html/bug-guix/2013-01/msg00239.html
1054 @c for why `-G' is needed.
1056 # groupadd --system guixbuild
1057 # for i in $(seq -w 1 10);
1059 useradd -g guixbuild -G guixbuild \
1060 -d /var/empty -s $(which nologin) \
1061 -c "Guix build user $i" --system \
1067 The number of build users determines how many build jobs may run in
1068 parallel, as specified by the @option{--max-jobs} option
1069 (@pxref{Invoking guix-daemon, @option{--max-jobs}}). To use
1070 @command{guix system vm} and related commands, you may need to add the
1071 build users to the @code{kvm} group so they can access @file{/dev/kvm},
1072 using @code{-G guixbuild,kvm} instead of @code{-G guixbuild}
1073 (@pxref{Invoking guix system}).
1075 The @code{guix-daemon} program may then be run as @code{root} with the
1076 following command@footnote{If your machine uses the systemd init system,
1077 dropping the @file{@var{prefix}/lib/systemd/system/guix-daemon.service}
1078 file in @file{/etc/systemd/system} will ensure that
1079 @command{guix-daemon} is automatically started. Similarly, if your
1080 machine uses the Upstart init system, drop the
1081 @file{@var{prefix}/lib/upstart/system/guix-daemon.conf}
1082 file in @file{/etc/init}.}:
1085 # guix-daemon --build-users-group=guixbuild
1090 This way, the daemon starts build processes in a chroot, under one of
1091 the @code{guixbuilder} users. On GNU/Linux, by default, the chroot
1092 environment contains nothing but:
1094 @c Keep this list in sync with libstore/build.cc! -----------------------
1097 a minimal @code{/dev} directory, created mostly independently from the
1098 host @code{/dev}@footnote{``Mostly'', because while the set of files
1099 that appear in the chroot's @code{/dev} is fixed, most of these files
1100 can only be created if the host has them.};
1103 the @code{/proc} directory; it only shows the processes of the container
1104 since a separate PID name space is used;
1107 @file{/etc/passwd} with an entry for the current user and an entry for
1111 @file{/etc/group} with an entry for the user's group;
1114 @file{/etc/hosts} with an entry that maps @code{localhost} to
1118 a writable @file{/tmp} directory.
1121 You can influence the directory where the daemon stores build trees
1122 @i{via} the @env{TMPDIR} environment variable. However, the build tree
1123 within the chroot is always called @file{/tmp/guix-build-@var{name}.drv-0},
1124 where @var{name} is the derivation name---e.g., @code{coreutils-8.24}.
1125 This way, the value of @env{TMPDIR} does not leak inside build
1126 environments, which avoids discrepancies in cases where build processes
1127 capture the name of their build tree.
1131 The daemon also honors the @env{http_proxy} and @env{https_proxy}
1132 environment variables for HTTP and HTTPS downloads it performs, be it
1133 for fixed-output derivations (@pxref{Derivations}) or for substitutes
1134 (@pxref{Substitutes}).
1136 If you are installing Guix as an unprivileged user, it is still possible
1137 to run @command{guix-daemon} provided you pass @option{--disable-chroot}.
1138 However, build processes will not be isolated from one another, and not
1139 from the rest of the system. Thus, build processes may interfere with
1140 each other, and may access programs, libraries, and other files
1141 available on the system---making it much harder to view them as
1142 @emph{pure} functions.
1145 @node Daemon Offload Setup
1146 @subsection Using the Offload Facility
1150 When desired, the build daemon can @dfn{offload} derivation builds to
1151 other machines running Guix, using the @code{offload} @dfn{build
1152 hook}@footnote{This feature is available only when
1153 @uref{https://github.com/artyom-poptsov/guile-ssh, Guile-SSH} is
1154 present.}. When that feature is enabled, a list of user-specified build
1155 machines is read from @file{/etc/guix/machines.scm}; every time a build
1156 is requested, for instance via @code{guix build}, the daemon attempts to
1157 offload it to one of the machines that satisfy the constraints of the
1158 derivation, in particular its system types---e.g., @code{x86_64-linux}.
1159 A single machine can have multiple system types, either because its
1160 architecture natively supports it, via emulation
1161 (@pxref{transparent-emulation-qemu, Transparent Emulation with QEMU}),
1162 or both. Missing prerequisites for the build are
1163 copied over SSH to the target machine, which then proceeds with the
1164 build; upon success the output(s) of the build are copied back to the
1165 initial machine. The offload facility comes with a basic scheduler that
1166 attempts to select the best machine. The best machine is chosen among
1167 the available machines based on criteria such as:
1171 The availability of a build slot. A build machine can have as many
1172 build slots (connections) as the value of the @code{parallel-builds}
1173 field of its @code{build-machine} object.
1176 Its relative speed, as defined via the @code{speed} field of its
1177 @code{build-machine} object.
1180 Its load. The normalized machine load must be lower than a threshold
1181 value, configurable via the @code{overload-threshold} field of its
1182 @code{build-machine} object.
1185 Disk space availability. More than a 100 MiB must be available.
1188 The @file{/etc/guix/machines.scm} file typically looks like this:
1191 (list (build-machine
1192 (name "eightysix.example.org")
1193 (systems (list "x86_64-linux" "i686-linux"))
1194 (host-key "ssh-ed25519 AAAAC3Nza@dots{}")
1196 (speed 2.)) ;incredibly fast!
1199 (name "armeight.example.org")
1200 (systems (list "aarch64-linux"))
1201 (host-key "ssh-rsa AAAAB3Nza@dots{}")
1204 (string-append (getenv "HOME")
1205 "/.ssh/identity-for-guix"))))
1209 In the example above we specify a list of two build machines, one for
1210 the @code{x86_64} and @code{i686} architectures and one for the
1211 @code{aarch64} architecture.
1213 In fact, this file is---not surprisingly!---a Scheme file that is
1214 evaluated when the @code{offload} hook is started. Its return value
1215 must be a list of @code{build-machine} objects. While this example
1216 shows a fixed list of build machines, one could imagine, say, using
1217 DNS-SD to return a list of potential build machines discovered in the
1218 local network (@pxref{Introduction, Guile-Avahi,, guile-avahi, Using
1219 Avahi in Guile Scheme Programs}). The @code{build-machine} data type is
1222 @deftp {Data Type} build-machine
1223 This data type represents build machines to which the daemon may offload
1224 builds. The important fields are:
1229 The host name of the remote machine.
1232 The system types the remote machine supports---e.g., @code{(list
1233 "x86_64-linux" "i686-linux")}.
1236 The user account to use when connecting to the remote machine over SSH.
1237 Note that the SSH key pair must @emph{not} be passphrase-protected, to
1238 allow non-interactive logins.
1241 This must be the machine's SSH @dfn{public host key} in OpenSSH format.
1242 This is used to authenticate the machine when we connect to it. It is a
1243 long string that looks like this:
1246 ssh-ed25519 AAAAC3NzaC@dots{}mde+UhL hint@@example.org
1249 If the machine is running the OpenSSH daemon, @command{sshd}, the host
1250 key can be found in a file such as
1251 @file{/etc/ssh/ssh_host_ed25519_key.pub}.
1253 If the machine is running the SSH daemon of GNU@tie{}lsh,
1254 @command{lshd}, the host key is in @file{/etc/lsh/host-key.pub} or a
1255 similar file. It can be converted to the OpenSSH format using
1256 @command{lsh-export-key} (@pxref{Converting keys,,, lsh, LSH Manual}):
1259 $ lsh-export-key --openssh < /etc/lsh/host-key.pub
1260 ssh-rsa AAAAB3NzaC1yc2EAAAAEOp8FoQAAAQEAs1eB46LV@dots{}
1265 A number of optional fields may be specified:
1269 @item @code{port} (default: @code{22})
1270 Port number of SSH server on the machine.
1272 @item @code{private-key} (default: @file{~root/.ssh/id_rsa})
1273 The SSH private key file to use when connecting to the machine, in
1274 OpenSSH format. This key must not be protected with a passphrase.
1276 Note that the default value is the private key @emph{of the root
1277 account}. Make sure it exists if you use the default.
1279 @item @code{compression} (default: @code{"zlib@@openssh.com,zlib"})
1280 @itemx @code{compression-level} (default: @code{3})
1281 The SSH-level compression methods and compression level requested.
1283 Note that offloading relies on SSH compression to reduce bandwidth usage
1284 when transferring files to and from build machines.
1286 @item @code{daemon-socket} (default: @code{"/var/guix/daemon-socket/socket"})
1287 File name of the Unix-domain socket @command{guix-daemon} is listening
1290 @item @code{overload-threshold} (default: @code{0.6})
1291 The load threshold above which a potential offload machine is
1292 disregarded by the offload scheduler. The value roughly translates to
1293 the total processor usage of the build machine, ranging from 0.0 (0%) to
1294 1.0 (100%). It can also be disabled by setting
1295 @code{overload-threshold} to @code{#f}.
1297 @item @code{parallel-builds} (default: @code{1})
1298 The number of builds that may run in parallel on the machine.
1300 @item @code{speed} (default: @code{1.0})
1301 A ``relative speed factor''. The offload scheduler will tend to prefer
1302 machines with a higher speed factor.
1304 @item @code{features} (default: @code{'()})
1305 A list of strings denoting specific features supported by the machine.
1306 An example is @code{"kvm"} for machines that have the KVM Linux modules
1307 and corresponding hardware support. Derivations can request features by
1308 name, and they will be scheduled on matching build machines.
1313 The @command{guix} command must be in the search path on the build
1314 machines. You can check whether this is the case by running:
1317 ssh build-machine guix repl --version
1320 There is one last thing to do once @file{machines.scm} is in place. As
1321 explained above, when offloading, files are transferred back and forth
1322 between the machine stores. For this to work, you first need to
1323 generate a key pair on each machine to allow the daemon to export signed
1324 archives of files from the store (@pxref{Invoking guix archive}):
1327 # guix archive --generate-key
1331 Each build machine must authorize the key of the master machine so that
1332 it accepts store items it receives from the master:
1335 # guix archive --authorize < master-public-key.txt
1339 Likewise, the master machine must authorize the key of each build machine.
1341 All the fuss with keys is here to express pairwise mutual trust
1342 relations between the master and the build machines. Concretely, when
1343 the master receives files from a build machine (and @i{vice versa}), its
1344 build daemon can make sure they are genuine, have not been tampered
1345 with, and that they are signed by an authorized key.
1347 @cindex offload test
1348 To test whether your setup is operational, run this command on the
1355 This will attempt to connect to each of the build machines specified in
1356 @file{/etc/guix/machines.scm}, make sure Guix is
1357 available on each machine, attempt to export to the machine and import
1358 from it, and report any error in the process.
1360 If you want to test a different machine file, just specify it on the
1364 # guix offload test machines-qualif.scm
1367 Last, you can test the subset of the machines whose name matches a
1368 regular expression like this:
1371 # guix offload test machines.scm '\.gnu\.org$'
1374 @cindex offload status
1375 To display the current load of all build hosts, run this command on the
1379 # guix offload status
1383 @node SELinux Support
1384 @subsection SELinux Support
1386 @cindex SELinux, daemon policy
1387 @cindex mandatory access control, SELinux
1388 @cindex security, guix-daemon
1389 Guix includes an SELinux policy file at @file{etc/guix-daemon.cil} that
1390 can be installed on a system where SELinux is enabled, in order to label
1391 Guix files and to specify the expected behavior of the daemon. Since
1392 Guix System does not provide an SELinux base policy, the daemon policy cannot
1393 be used on Guix System.
1395 @subsubsection Installing the SELinux policy
1396 @cindex SELinux, policy installation
1397 To install the policy run this command as root:
1400 semodule -i etc/guix-daemon.cil
1403 Then relabel the file system with @code{restorecon} or by a different
1404 mechanism provided by your system.
1406 Once the policy is installed, the file system has been relabeled, and
1407 the daemon has been restarted, it should be running in the
1408 @code{guix_daemon_t} context. You can confirm this with the following
1412 ps -Zax | grep guix-daemon
1415 Monitor the SELinux log files as you run a command like @code{guix build
1416 hello} to convince yourself that SELinux permits all necessary
1419 @subsubsection Limitations
1420 @cindex SELinux, limitations
1422 This policy is not perfect. Here is a list of limitations or quirks
1423 that should be considered when deploying the provided SELinux policy for
1428 @code{guix_daemon_socket_t} isn’t actually used. None of the socket
1429 operations involve contexts that have anything to do with
1430 @code{guix_daemon_socket_t}. It doesn’t hurt to have this unused label,
1431 but it would be preferrable to define socket rules for only this label.
1434 @code{guix gc} cannot access arbitrary links to profiles. By design,
1435 the file label of the destination of a symlink is independent of the
1436 file label of the link itself. Although all profiles under
1437 $localstatedir are labelled, the links to these profiles inherit the
1438 label of the directory they are in. For links in the user’s home
1439 directory this will be @code{user_home_t}. But for links from the root
1440 user’s home directory, or @file{/tmp}, or the HTTP server’s working
1441 directory, etc, this won’t work. @code{guix gc} would be prevented from
1442 reading and following these links.
1445 The daemon’s feature to listen for TCP connections might no longer work.
1446 This might require extra rules, because SELinux treats network sockets
1447 differently from files.
1450 Currently all files with a name matching the regular expression
1451 @code{/gnu/store/.+-(guix-.+|profile)/bin/guix-daemon} are assigned the
1452 label @code{guix_daemon_exec_t}; this means that @emph{any} file with
1453 that name in any profile would be permitted to run in the
1454 @code{guix_daemon_t} domain. This is not ideal. An attacker could
1455 build a package that provides this executable and convince a user to
1456 install and run it, which lifts it into the @code{guix_daemon_t} domain.
1457 At that point SELinux could not prevent it from accessing files that are
1458 allowed for processes in that domain.
1460 You will need to relabel the store directory after all upgrades to
1461 @file{guix-daemon}, such as after running @code{guix pull}. Assuming the
1462 store is in @file{/gnu}, you can do this with @code{restorecon -vR /gnu},
1463 or by other means provided by your operating system.
1465 We could generate a much more restrictive policy at installation time,
1466 so that only the @emph{exact} file name of the currently installed
1467 @code{guix-daemon} executable would be labelled with
1468 @code{guix_daemon_exec_t}, instead of using a broad regular expression.
1469 The downside is that root would have to install or upgrade the policy at
1470 installation time whenever the Guix package that provides the
1471 effectively running @code{guix-daemon} executable is upgraded.
1474 @node Invoking guix-daemon
1475 @section Invoking @command{guix-daemon}
1477 The @command{guix-daemon} program implements all the functionality to
1478 access the store. This includes launching build processes, running the
1479 garbage collector, querying the availability of a build result, etc. It
1480 is normally run as @code{root} like this:
1483 # guix-daemon --build-users-group=guixbuild
1487 For details on how to set it up, @pxref{Setting Up the Daemon}.
1490 @cindex container, build environment
1491 @cindex build environment
1492 @cindex reproducible builds
1493 By default, @command{guix-daemon} launches build processes under
1494 different UIDs, taken from the build group specified with
1495 @option{--build-users-group}. In addition, each build process is run in a
1496 chroot environment that only contains the subset of the store that the
1497 build process depends on, as specified by its derivation
1498 (@pxref{Programming Interface, derivation}), plus a set of specific
1499 system directories. By default, the latter contains @file{/dev} and
1500 @file{/dev/pts}. Furthermore, on GNU/Linux, the build environment is a
1501 @dfn{container}: in addition to having its own file system tree, it has
1502 a separate mount name space, its own PID name space, network name space,
1503 etc. This helps achieve reproducible builds (@pxref{Features}).
1505 When the daemon performs a build on behalf of the user, it creates a
1506 build directory under @file{/tmp} or under the directory specified by
1507 its @env{TMPDIR} environment variable. This directory is shared with
1508 the container for the duration of the build, though within the container,
1509 the build tree is always called @file{/tmp/guix-build-@var{name}.drv-0}.
1511 The build directory is automatically deleted upon completion, unless the
1512 build failed and the client specified @option{--keep-failed}
1513 (@pxref{Common Build Options, @option{--keep-failed}}).
1515 The daemon listens for connections and spawns one sub-process for each session
1516 started by a client (one of the @command{guix} sub-commands). The
1517 @command{guix processes} command allows you to get an overview of the activity
1518 on your system by viewing each of the active sessions and clients.
1519 @xref{Invoking guix processes}, for more information.
1521 The following command-line options are supported:
1524 @item --build-users-group=@var{group}
1525 Take users from @var{group} to run build processes (@pxref{Setting Up
1526 the Daemon, build users}).
1528 @item --no-substitutes
1530 Do not use substitutes for build products. That is, always build things
1531 locally instead of allowing downloads of pre-built binaries
1532 (@pxref{Substitutes}).
1534 When the daemon runs with @option{--no-substitutes}, clients can still
1535 explicitly enable substitution @i{via} the @code{set-build-options}
1536 remote procedure call (@pxref{The Store}).
1538 @anchor{daemon-substitute-urls}
1539 @item --substitute-urls=@var{urls}
1540 Consider @var{urls} the default whitespace-separated list of substitute
1541 source URLs. When this option is omitted,
1542 @indicateurl{https://@value{SUBSTITUTE-SERVER}} is used.
1544 This means that substitutes may be downloaded from @var{urls}, as long
1545 as they are signed by a trusted signature (@pxref{Substitutes}).
1547 @xref{Getting Substitutes from Other Servers}, for more information on
1548 how to configure the daemon to get substitutes from other servers.
1552 Do not use offload builds to other machines (@pxref{Daemon Offload
1553 Setup}). That is, always build things locally instead of offloading
1554 builds to remote machines.
1556 @item --cache-failures
1557 Cache build failures. By default, only successful builds are cached.
1559 When this option is used, @command{guix gc --list-failures} can be used
1560 to query the set of store items marked as failed; @command{guix gc
1561 --clear-failures} removes store items from the set of cached failures.
1562 @xref{Invoking guix gc}.
1564 @item --cores=@var{n}
1566 Use @var{n} CPU cores to build each derivation; @code{0} means as many
1569 The default value is @code{0}, but it may be overridden by clients, such
1570 as the @option{--cores} option of @command{guix build} (@pxref{Invoking
1573 The effect is to define the @env{NIX_BUILD_CORES} environment variable
1574 in the build process, which can then use it to exploit internal
1575 parallelism---for instance, by running @code{make -j$NIX_BUILD_CORES}.
1577 @item --max-jobs=@var{n}
1579 Allow at most @var{n} build jobs in parallel. The default value is
1580 @code{1}. Setting it to @code{0} means that no builds will be performed
1581 locally; instead, the daemon will offload builds (@pxref{Daemon Offload
1582 Setup}), or simply fail.
1584 @item --max-silent-time=@var{seconds}
1585 When the build or substitution process remains silent for more than
1586 @var{seconds}, terminate it and report a build failure.
1588 The default value is @code{0}, which disables the timeout.
1590 The value specified here can be overridden by clients (@pxref{Common
1591 Build Options, @option{--max-silent-time}}).
1593 @item --timeout=@var{seconds}
1594 Likewise, when the build or substitution process lasts for more than
1595 @var{seconds}, terminate it and report a build failure.
1597 The default value is @code{0}, which disables the timeout.
1599 The value specified here can be overridden by clients (@pxref{Common
1600 Build Options, @option{--timeout}}).
1602 @item --rounds=@var{N}
1603 Build each derivation @var{n} times in a row, and raise an error if
1604 consecutive build results are not bit-for-bit identical. Note that this
1605 setting can be overridden by clients such as @command{guix build}
1606 (@pxref{Invoking guix build}).
1608 When used in conjunction with @option{--keep-failed}, the differing
1609 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
1610 This makes it easy to look for differences between the two results.
1613 Produce debugging output.
1615 This is useful to debug daemon start-up issues, but then it may be
1616 overridden by clients, for example the @option{--verbosity} option of
1617 @command{guix build} (@pxref{Invoking guix build}).
1619 @item --chroot-directory=@var{dir}
1620 Add @var{dir} to the build chroot.
1622 Doing this may change the result of build processes---for instance if
1623 they use optional dependencies found in @var{dir} when it is available,
1624 and not otherwise. For that reason, it is not recommended to do so.
1625 Instead, make sure that each derivation declares all the inputs that it
1628 @item --disable-chroot
1629 Disable chroot builds.
1631 Using this option is not recommended since, again, it would allow build
1632 processes to gain access to undeclared dependencies. It is necessary,
1633 though, when @command{guix-daemon} is running under an unprivileged user
1636 @item --log-compression=@var{type}
1637 Compress build logs according to @var{type}, one of @code{gzip},
1638 @code{bzip2}, or @code{none}.
1640 Unless @option{--lose-logs} is used, all the build logs are kept in the
1641 @var{localstatedir}. To save space, the daemon automatically compresses
1642 them with Bzip2 by default.
1644 @item --discover[=yes|no]
1645 Whether to discover substitute servers on the local network using mDNS
1648 This feature is still experimental. However, here are a few
1653 It might be faster/less expensive than fetching from remote servers;
1655 There are no security risks, only genuine substitutes will be used
1656 (@pxref{Substitute Authentication});
1658 An attacker advertising @command{guix publish} on your LAN cannot serve
1659 you malicious binaries, but they can learn what software you’re
1662 Servers may serve substitute over HTTP, unencrypted, so anyone on the
1663 LAN can see what software you’re installing.
1666 It is also possible to enable or disable substitute server discovery at
1667 run-time by running:
1670 herd discover guix-daemon on
1671 herd discover guix-daemon off
1674 @item --disable-deduplication
1675 @cindex deduplication
1676 Disable automatic file ``deduplication'' in the store.
1678 By default, files added to the store are automatically ``deduplicated'':
1679 if a newly added file is identical to another one found in the store,
1680 the daemon makes the new file a hard link to the other file. This can
1681 noticeably reduce disk usage, at the expense of slightly increased
1682 input/output load at the end of a build process. This option disables
1685 @item --gc-keep-outputs[=yes|no]
1686 Tell whether the garbage collector (GC) must keep outputs of live
1690 @cindex garbage collector roots
1691 When set to @code{yes}, the GC will keep the outputs of any live
1692 derivation available in the store---the @file{.drv} files. The default
1693 is @code{no}, meaning that derivation outputs are kept only if they are
1694 reachable from a GC root. @xref{Invoking guix gc}, for more on GC
1697 @item --gc-keep-derivations[=yes|no]
1698 Tell whether the garbage collector (GC) must keep derivations
1699 corresponding to live outputs.
1701 When set to @code{yes}, as is the case by default, the GC keeps
1702 derivations---i.e., @file{.drv} files---as long as at least one of their
1703 outputs is live. This allows users to keep track of the origins of
1704 items in their store. Setting it to @code{no} saves a bit of disk
1707 In this way, setting @option{--gc-keep-derivations} to @code{yes} causes
1708 liveness to flow from outputs to derivations, and setting
1709 @option{--gc-keep-outputs} to @code{yes} causes liveness to flow from
1710 derivations to outputs. When both are set to @code{yes}, the effect is
1711 to keep all the build prerequisites (the sources, compiler, libraries,
1712 and other build-time tools) of live objects in the store, regardless of
1713 whether these prerequisites are reachable from a GC root. This is
1714 convenient for developers since it saves rebuilds or downloads.
1716 @item --impersonate-linux-2.6
1717 On Linux-based systems, impersonate Linux 2.6. This means that the
1718 kernel's @command{uname} system call will report 2.6 as the release number.
1720 This might be helpful to build programs that (usually wrongfully) depend
1721 on the kernel version number.
1724 Do not keep build logs. By default they are kept under
1725 @file{@var{localstatedir}/guix/log}.
1727 @item --system=@var{system}
1728 Assume @var{system} as the current system type. By default it is the
1729 architecture/kernel pair found at configure time, such as
1730 @code{x86_64-linux}.
1732 @item --listen=@var{endpoint}
1733 Listen for connections on @var{endpoint}. @var{endpoint} is interpreted
1734 as the file name of a Unix-domain socket if it starts with
1735 @code{/} (slash sign). Otherwise, @var{endpoint} is interpreted as a
1736 host name or host name and port to listen to. Here are a few examples:
1739 @item --listen=/gnu/var/daemon
1740 Listen for connections on the @file{/gnu/var/daemon} Unix-domain socket,
1741 creating it if needed.
1743 @item --listen=localhost
1744 @cindex daemon, remote access
1745 @cindex remote access to the daemon
1746 @cindex daemon, cluster setup
1747 @cindex clusters, daemon setup
1748 Listen for TCP connections on the network interface corresponding to
1749 @code{localhost}, on port 44146.
1751 @item --listen=128.0.0.42:1234
1752 Listen for TCP connections on the network interface corresponding to
1753 @code{128.0.0.42}, on port 1234.
1756 This option can be repeated multiple times, in which case
1757 @command{guix-daemon} accepts connections on all the specified
1758 endpoints. Users can tell client commands what endpoint to connect to
1759 by setting the @env{GUIX_DAEMON_SOCKET} environment variable
1760 (@pxref{The Store, @env{GUIX_DAEMON_SOCKET}}).
1763 The daemon protocol is @emph{unauthenticated and unencrypted}. Using
1764 @option{--listen=@var{host}} is suitable on local networks, such as
1765 clusters, where only trusted nodes may connect to the build daemon. In
1766 other cases where remote access to the daemon is needed, we recommend
1767 using Unix-domain sockets along with SSH.
1770 When @option{--listen} is omitted, @command{guix-daemon} listens for
1771 connections on the Unix-domain socket located at
1772 @file{@var{localstatedir}/guix/daemon-socket/socket}.
1776 @node Application Setup
1777 @section Application Setup
1779 @cindex foreign distro
1780 When using Guix on top of GNU/Linux distribution other than Guix System---a
1781 so-called @dfn{foreign distro}---a few additional steps are needed to
1782 get everything in place. Here are some of them.
1786 @anchor{locales-and-locpath}
1787 @cindex locales, when not on Guix System
1789 @vindex GUIX_LOCPATH
1790 Packages installed @i{via} Guix will not use the locale data of the
1791 host system. Instead, you must first install one of the locale packages
1792 available with Guix and then define the @env{GUIX_LOCPATH} environment
1796 $ guix install glibc-locales
1797 $ export GUIX_LOCPATH=$HOME/.guix-profile/lib/locale
1800 Note that the @code{glibc-locales} package contains data for all the
1801 locales supported by the GNU@tie{}libc and weighs in at around
1802 917@tie{}MiB@. Alternatively, the @code{glibc-utf8-locales} is smaller but
1803 limited to a few UTF-8 locales.
1805 The @env{GUIX_LOCPATH} variable plays a role similar to @env{LOCPATH}
1806 (@pxref{Locale Names, @env{LOCPATH},, libc, The GNU C Library Reference
1807 Manual}). There are two important differences though:
1811 @env{GUIX_LOCPATH} is honored only by the libc in Guix, and not by the libc
1812 provided by foreign distros. Thus, using @env{GUIX_LOCPATH} allows you
1813 to make sure the programs of the foreign distro will not end up loading
1814 incompatible locale data.
1817 libc suffixes each entry of @env{GUIX_LOCPATH} with @code{/X.Y}, where
1818 @code{X.Y} is the libc version---e.g., @code{2.22}. This means that,
1819 should your Guix profile contain a mixture of programs linked against
1820 different libc version, each libc version will only try to load locale
1821 data in the right format.
1824 This is important because the locale data format used by different libc
1825 versions may be incompatible.
1827 @subsection Name Service Switch
1829 @cindex name service switch, glibc
1830 @cindex NSS (name service switch), glibc
1831 @cindex nscd (name service caching daemon)
1832 @cindex name service caching daemon (nscd)
1833 When using Guix on a foreign distro, we @emph{strongly recommend} that
1834 the system run the GNU C library's @dfn{name service cache daemon},
1835 @command{nscd}, which should be listening on the
1836 @file{/var/run/nscd/socket} socket. Failing to do that, applications
1837 installed with Guix may fail to look up host names or user accounts, or
1838 may even crash. The next paragraphs explain why.
1840 @cindex @file{nsswitch.conf}
1841 The GNU C library implements a @dfn{name service switch} (NSS), which is
1842 an extensible mechanism for ``name lookups'' in general: host name
1843 resolution, user accounts, and more (@pxref{Name Service Switch,,, libc,
1844 The GNU C Library Reference Manual}).
1846 @cindex Network information service (NIS)
1847 @cindex NIS (Network information service)
1848 Being extensible, the NSS supports @dfn{plugins}, which provide new name
1849 lookup implementations: for example, the @code{nss-mdns} plugin allow
1850 resolution of @code{.local} host names, the @code{nis} plugin allows
1851 user account lookup using the Network information service (NIS), and so
1852 on. These extra ``lookup services'' are configured system-wide in
1853 @file{/etc/nsswitch.conf}, and all the programs running on the system
1854 honor those settings (@pxref{NSS Configuration File,,, libc, The GNU C
1857 When they perform a name lookup---for instance by calling the
1858 @code{getaddrinfo} function in C---applications first try to connect to
1859 the nscd; on success, nscd performs name lookups on their behalf. If
1860 the nscd is not running, then they perform the name lookup by
1861 themselves, by loading the name lookup services into their own address
1862 space and running it. These name lookup services---the
1863 @file{libnss_*.so} files---are @code{dlopen}'d, but they may come from
1864 the host system's C library, rather than from the C library the
1865 application is linked against (the C library coming from Guix).
1867 And this is where the problem is: if your application is linked against
1868 Guix's C library (say, glibc 2.24) and tries to load NSS plugins from
1869 another C library (say, @code{libnss_mdns.so} for glibc 2.22), it will
1870 likely crash or have its name lookups fail unexpectedly.
1872 Running @command{nscd} on the system, among other advantages, eliminates
1873 this binary incompatibility problem because those @code{libnss_*.so}
1874 files are loaded in the @command{nscd} process, not in applications
1877 @subsection X11 Fonts
1880 The majority of graphical applications use Fontconfig to locate and
1881 load fonts and perform X11-client-side rendering. The @code{fontconfig}
1882 package in Guix looks for fonts in @file{$HOME/.guix-profile}
1883 by default. Thus, to allow graphical applications installed with Guix
1884 to display fonts, you have to install fonts with Guix as well.
1885 Essential font packages include @code{gs-fonts}, @code{font-dejavu}, and
1886 @code{font-gnu-freefont}.
1888 @cindex @code{fc-cache}
1890 Once you have installed or removed fonts, or when you notice an
1891 application that does not find fonts, you may need to install Fontconfig
1892 and to force an update of its font cache by running:
1895 guix install fontconfig
1899 To display text written in Chinese languages, Japanese, or Korean in
1900 graphical applications, consider installing
1901 @code{font-adobe-source-han-sans} or @code{font-wqy-zenhei}. The former
1902 has multiple outputs, one per language family (@pxref{Packages with
1903 Multiple Outputs}). For instance, the following command installs fonts
1904 for Chinese languages:
1907 guix install font-adobe-source-han-sans:cn
1910 @cindex @code{xterm}
1911 Older programs such as @command{xterm} do not use Fontconfig and instead
1912 rely on server-side font rendering. Such programs require to specify a
1913 full name of a font using XLFD (X Logical Font Description), like this:
1916 -*-dejavu sans-medium-r-normal-*-*-100-*-*-*-*-*-1
1919 To be able to use such full names for the TrueType fonts installed in
1920 your Guix profile, you need to extend the font path of the X server:
1922 @c Note: 'xset' does not accept symlinks so the trick below arranges to
1923 @c get at the real directory. See <https://bugs.gnu.org/30655>.
1925 xset +fp $(dirname $(readlink -f ~/.guix-profile/share/fonts/truetype/fonts.dir))
1928 @cindex @code{xlsfonts}
1929 After that, you can run @code{xlsfonts} (from @code{xlsfonts} package)
1930 to make sure your TrueType fonts are listed there.
1933 @subsection X.509 Certificates
1935 @cindex @code{nss-certs}
1936 The @code{nss-certs} package provides X.509 certificates, which allow
1937 programs to authenticate Web servers accessed over HTTPS.
1939 When using Guix on a foreign distro, you can install this package and
1940 define the relevant environment variables so that packages know where to
1941 look for certificates. @xref{X.509 Certificates}, for detailed
1944 @subsection Emacs Packages
1946 @cindex @code{emacs}
1947 When you install Emacs packages with Guix, the Elisp files are placed
1948 under the @file{share/emacs/site-lisp/} directory of the profile in
1949 which they are installed. The Elisp libraries are made available to
1950 Emacs through the @env{EMACSLOADPATH} environment variable, which is
1951 set when installing Emacs itself.
1953 Additionally, autoload definitions are automatically evaluated at the
1954 initialization of Emacs, by the Guix-specific
1955 @code{guix-emacs-autoload-packages} procedure. If, for some reason, you
1956 want to avoid auto-loading the Emacs packages installed with Guix, you
1957 can do so by running Emacs with the @option{--no-site-file} option
1958 (@pxref{Init File,,, emacs, The GNU Emacs Manual}).
1961 @node Upgrading Guix
1962 @section Upgrading Guix
1964 @cindex Upgrading Guix, on a foreign distro
1966 To upgrade Guix, run:
1972 @xref{Invoking guix pull}, for more information.
1974 @cindex upgrading Guix for the root user, on a foreign distro
1975 @cindex upgrading the Guix daemon, on a foreign distro
1976 @cindex @command{guix pull} for the root user, on a foreign distro
1978 On a foreign distro, you can upgrade the build daemon by running:
1985 followed by (assuming your distro uses the systemd service management
1989 systemctl restart guix-daemon.service
1992 On Guix System, upgrading the daemon is achieved by reconfiguring the
1993 system (@pxref{Invoking guix system, @code{guix system reconfigure}}).
1997 @c *********************************************************************
1998 @node System Installation
1999 @chapter System Installation
2001 @cindex installing Guix System
2002 @cindex Guix System, installation
2003 This section explains how to install Guix System
2004 on a machine. Guix, as a package manager, can
2005 also be installed on top of a running GNU/Linux system,
2006 @pxref{Installation}.
2010 @c This paragraph is for people reading this from tty2 of the
2011 @c installation image.
2012 You are reading this documentation with an Info reader. For details on
2013 how to use it, hit the @key{RET} key (``return'' or ``enter'') on the
2014 link that follows: @pxref{Top, Info reader,, info-stnd, Stand-alone GNU
2015 Info}. Hit @kbd{l} afterwards to come back here.
2017 Alternatively, run @command{info info} in another tty to keep the manual
2023 * Limitations:: What you can expect.
2024 * Hardware Considerations:: Supported hardware.
2025 * USB Stick and DVD Installation:: Preparing the installation medium.
2026 * Preparing for Installation:: Networking, partitioning, etc.
2027 * Guided Graphical Installation:: Easy graphical installation.
2028 * Manual Installation:: Manual installation for wizards.
2029 * After System Installation:: When installation succeeded.
2030 * Installing Guix in a VM:: Guix System playground.
2031 * Building the Installation Image:: How this comes to be.
2035 @section Limitations
2037 We consider Guix System to be ready for a wide range of ``desktop'' and server
2038 use cases. The reliability guarantees it provides---transactional upgrades
2039 and rollbacks, reproducibility---make it a solid foundation.
2041 Nevertheless, before you proceed with the installation, be aware of the
2042 following noteworthy limitations applicable to version @value{VERSION}:
2046 More and more system services are provided (@pxref{Services}), but some
2050 GNOME, Xfce, LXDE, and Enlightenment are available (@pxref{Desktop Services}),
2051 as well as a number of X11 window managers. However, KDE is currently
2055 More than a disclaimer, this is an invitation to report issues (and success
2056 stories!), and to join us in improving it. @xref{Contributing}, for more
2060 @node Hardware Considerations
2061 @section Hardware Considerations
2063 @cindex hardware support on Guix System
2064 GNU@tie{}Guix focuses on respecting the user's computing freedom. It
2065 builds around the kernel Linux-libre, which means that only hardware for
2066 which free software drivers and firmware exist is supported. Nowadays,
2067 a wide range of off-the-shelf hardware is supported on
2068 GNU/Linux-libre---from keyboards to graphics cards to scanners and
2069 Ethernet controllers. Unfortunately, there are still areas where
2070 hardware vendors deny users control over their own computing, and such
2071 hardware is not supported on Guix System.
2073 @cindex WiFi, hardware support
2074 One of the main areas where free drivers or firmware are lacking is WiFi
2075 devices. WiFi devices known to work include those using Atheros chips
2076 (AR9271 and AR7010), which corresponds to the @code{ath9k} Linux-libre
2077 driver, and those using Broadcom/AirForce chips (BCM43xx with
2078 Wireless-Core Revision 5), which corresponds to the @code{b43-open}
2079 Linux-libre driver. Free firmware exists for both and is available
2080 out-of-the-box on Guix System, as part of @code{%base-firmware}
2081 (@pxref{operating-system Reference, @code{firmware}}).
2083 @cindex RYF, Respects Your Freedom
2084 The @uref{https://www.fsf.org/, Free Software Foundation} runs
2085 @uref{https://www.fsf.org/ryf, @dfn{Respects Your Freedom}} (RYF), a
2086 certification program for hardware products that respect your freedom
2087 and your privacy and ensure that you have control over your device. We
2088 encourage you to check the list of RYF-certified devices.
2090 Another useful resource is the @uref{https://www.h-node.org/, H-Node}
2091 web site. It contains a catalog of hardware devices with information
2092 about their support in GNU/Linux.
2095 @node USB Stick and DVD Installation
2096 @section USB Stick and DVD Installation
2098 An ISO-9660 installation image that can be written to a USB stick or
2099 burnt to a DVD can be downloaded from
2100 @indicateurl{@value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz},
2101 where you can replace @code{x86_64-linux} with one of:
2105 for a GNU/Linux system on Intel/AMD-compatible 64-bit CPUs;
2108 for a 32-bit GNU/Linux system on Intel-compatible CPUs.
2111 @c start duplication of authentication part from ``Binary Installation''
2112 Make sure to download the associated @file{.sig} file and to verify the
2113 authenticity of the image against it, along these lines:
2116 $ wget @value{BASE-URL}/guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2117 $ gpg --verify guix-system-install-@value{VERSION}.x86_64-linux.iso.xz.sig
2120 If that command fails because you do not have the required public key,
2121 then run this command to import it:
2124 $ wget @value{OPENPGP-SIGNING-KEY-URL} \
2125 -qO - | gpg --import -
2129 and rerun the @code{gpg --verify} command.
2131 Take note that a warning like ``This key is not certified with a trusted
2132 signature!'' is normal.
2136 This image contains the tools necessary for an installation.
2137 It is meant to be copied @emph{as is} to a large-enough USB stick or DVD.
2139 @unnumberedsubsec Copying to a USB Stick
2141 To copy the image to a USB stick, follow these steps:
2145 Decompress the image using the @command{xz} command:
2148 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2152 Insert a USB stick of 1@tie{}GiB or more into your machine, and determine
2153 its device name. Assuming that the USB stick is known as @file{/dev/sdX},
2154 copy the image with:
2157 dd if=guix-system-install-@value{VERSION}.x86_64-linux.iso of=/dev/sdX status=progress
2161 Access to @file{/dev/sdX} usually requires root privileges.
2164 @unnumberedsubsec Burning on a DVD
2166 To copy the image to a DVD, follow these steps:
2170 Decompress the image using the @command{xz} command:
2173 xz -d guix-system-install-@value{VERSION}.x86_64-linux.iso.xz
2177 Insert a blank DVD into your machine, and determine
2178 its device name. Assuming that the DVD drive is known as @file{/dev/srX},
2179 copy the image with:
2182 growisofs -dvd-compat -Z /dev/srX=guix-system-install-@value{VERSION}.x86_64-linux.iso
2185 Access to @file{/dev/srX} usually requires root privileges.
2188 @unnumberedsubsec Booting
2190 Once this is done, you should be able to reboot the system and boot from
2191 the USB stick or DVD@. The latter usually requires you to get in the
2192 BIOS or UEFI boot menu, where you can choose to boot from the USB stick.
2193 In order to boot from Libreboot, switch to the command mode by pressing
2194 the @kbd{c} key and type @command{search_grub usb}.
2196 @xref{Installing Guix in a VM}, if, instead, you would like to install
2197 Guix System in a virtual machine (VM).
2200 @node Preparing for Installation
2201 @section Preparing for Installation
2203 Once you have booted, you can use the guided graphical installer, which makes
2204 it easy to get started (@pxref{Guided Graphical Installation}). Alternatively,
2205 if you are already familiar with GNU/Linux and if you want more control than
2206 what the graphical installer provides, you can choose the ``manual''
2207 installation process (@pxref{Manual Installation}).
2209 The graphical installer is available on TTY1. You can obtain root shells on
2210 TTYs 3 to 6 by hitting @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, etc. TTY2 shows
2211 this documentation and you can reach it with @kbd{ctrl-alt-f2}. Documentation
2212 is browsable using the Info reader commands (@pxref{Top,,, info-stnd,
2213 Stand-alone GNU Info}). The installation system runs the GPM mouse daemon,
2214 which allows you to select text with the left mouse button and to paste it
2215 with the middle button.
2218 Installation requires access to the Internet so that any missing
2219 dependencies of your system configuration can be downloaded. See the
2220 ``Networking'' section below.
2223 @node Guided Graphical Installation
2224 @section Guided Graphical Installation
2226 The graphical installer is a text-based user interface. It will guide you,
2227 with dialog boxes, through the steps needed to install GNU@tie{}Guix System.
2229 The first dialog boxes allow you to set up the system as you use it during the
2230 installation: you can choose the language, keyboard layout, and set up
2231 networking, which will be used during the installation. The image below shows
2232 the networking dialog.
2234 @image{images/installer-network,5in,, networking setup with the graphical installer}
2236 Later steps allow you to partition your hard disk, as shown in the image
2237 below, to choose whether or not to use encrypted file systems, to enter the
2238 host name and root password, and to create an additional account, among other
2241 @image{images/installer-partitions,5in,, partitioning with the graphical installer}
2243 Note that, at any time, the installer allows you to exit the current
2244 installation step and resume at a previous step, as show in the image below.
2246 @image{images/installer-resume,5in,, resuming the installation process}
2248 Once you're done, the installer produces an operating system configuration and
2249 displays it (@pxref{Using the Configuration System}). At that point you can
2250 hit ``OK'' and installation will proceed. On success, you can reboot into the
2251 new system and enjoy. @xref{After System Installation}, for what's next!
2254 @node Manual Installation
2255 @section Manual Installation
2257 This section describes how you would ``manually'' install GNU@tie{}Guix System
2258 on your machine. This option requires familiarity with GNU/Linux, with the
2259 shell, and with common administration tools. If you think this is not for
2260 you, consider using the guided graphical installer (@pxref{Guided Graphical
2263 The installation system provides root shells on TTYs 3 to 6; press
2264 @kbd{ctrl-alt-f3}, @kbd{ctrl-alt-f4}, and so on to reach them. It includes
2265 many common tools needed to install the system. But it is also a full-blown
2266 Guix System, which means that you can install additional packages, should you
2267 need it, using @command{guix package} (@pxref{Invoking guix package}).
2270 * Keyboard Layout and Networking and Partitioning:: Initial setup.
2271 * Proceeding with the Installation:: Installing.
2274 @node Keyboard Layout and Networking and Partitioning
2275 @subsection Keyboard Layout, Networking, and Partitioning
2277 Before you can install the system, you may want to adjust the keyboard layout,
2278 set up networking, and partition your target hard disk. This section will
2279 guide you through this.
2281 @subsubsection Keyboard Layout
2283 @cindex keyboard layout
2284 The installation image uses the US qwerty keyboard layout. If you want
2285 to change it, you can use the @command{loadkeys} command. For example,
2286 the following command selects the Dvorak keyboard layout:
2292 See the files under @file{/run/current-system/profile/share/keymaps} for
2293 a list of available keyboard layouts. Run @command{man loadkeys} for
2296 @subsubsection Networking
2298 Run the following command to see what your network interfaces are called:
2305 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2311 @c https://cgit.freedesktop.org/systemd/systemd/tree/src/udev/udev-builtin-net_id.c#n20
2312 Wired interfaces have a name starting with @samp{e}; for example, the
2313 interface corresponding to the first on-board Ethernet controller is
2314 called @samp{eno1}. Wireless interfaces have a name starting with
2315 @samp{w}, like @samp{w1p2s0}.
2318 @item Wired connection
2319 To configure a wired network run the following command, substituting
2320 @var{interface} with the name of the wired interface you want to use.
2323 ifconfig @var{interface} up
2327 @dots{} or, using the GNU/Linux-specific @command{ip} command:
2330 ip link set @var{interface} up
2333 @item Wireless connection
2336 To configure wireless networking, you can create a configuration file
2337 for the @command{wpa_supplicant} configuration tool (its location is not
2338 important) using one of the available text editors such as
2342 nano wpa_supplicant.conf
2345 As an example, the following stanza can go to this file and will work
2346 for many wireless networks, provided you give the actual SSID and
2347 passphrase for the network you are connecting to:
2351 ssid="@var{my-ssid}"
2353 psk="the network's secret passphrase"
2357 Start the wireless service and run it in the background with the
2358 following command (substitute @var{interface} with the name of the
2359 network interface you want to use):
2362 wpa_supplicant -c wpa_supplicant.conf -i @var{interface} -B
2365 Run @command{man wpa_supplicant} for more information.
2369 At this point, you need to acquire an IP address. On a network where IP
2370 addresses are automatically assigned @i{via} DHCP, you can run:
2373 dhclient -v @var{interface}
2376 Try to ping a server to see if networking is up and running:
2382 Setting up network access is almost always a requirement because the
2383 image does not contain all the software and tools that may be needed.
2385 @cindex proxy, during system installation
2386 If you need HTTP and HTTPS access to go through a proxy, run the
2390 herd set-http-proxy guix-daemon @var{URL}
2394 where @var{URL} is the proxy URL, for example
2395 @code{http://example.org:8118}.
2397 @cindex installing over SSH
2398 If you want to, you can continue the installation remotely by starting
2402 herd start ssh-daemon
2405 Make sure to either set a password with @command{passwd}, or configure
2406 OpenSSH public key authentication before logging in.
2408 @subsubsection Disk Partitioning
2410 Unless this has already been done, the next step is to partition, and
2411 then format the target partition(s).
2413 The installation image includes several partitioning tools, including
2414 Parted (@pxref{Overview,,, parted, GNU Parted User Manual}),
2415 @command{fdisk}, and @command{cfdisk}. Run it and set up your disk with
2416 the partition layout you want:
2422 If your disk uses the GUID Partition Table (GPT) format and you plan to
2423 install BIOS-based GRUB (which is the default), make sure a BIOS Boot
2424 Partition is available (@pxref{BIOS installation,,, grub, GNU GRUB
2427 @cindex EFI, installation
2428 @cindex UEFI, installation
2429 @cindex ESP, EFI system partition
2430 If you instead wish to use EFI-based GRUB, a FAT32 @dfn{EFI System Partition}
2431 (ESP) is required. This partition can be mounted at @file{/boot/efi} for
2432 instance and must have the @code{esp} flag set. E.g., for @command{parted}:
2435 parted /dev/sda set 1 esp on
2439 @vindex grub-bootloader
2440 @vindex grub-efi-bootloader
2441 Unsure whether to use EFI- or BIOS-based GRUB? If the directory
2442 @file{/sys/firmware/efi} exists in the installation image, then you should
2443 probably perform an EFI installation, using @code{grub-efi-bootloader}.
2444 Otherwise you should use the BIOS-based GRUB, known as
2445 @code{grub-bootloader}. @xref{Bootloader Configuration}, for more info on
2449 Once you are done partitioning the target hard disk drive, you have to
2450 create a file system on the relevant partition(s)@footnote{Currently
2451 Guix System only supports ext4, btrfs, JFS, and F2FS file systems. In
2452 particular, code that reads file system UUIDs and labels only works for these
2453 file system types.}. For the ESP, if you have one and assuming it is
2454 @file{/dev/sda1}, run:
2457 mkfs.fat -F32 /dev/sda1
2460 For the root file system, ext4 is the most widely used format. Other
2461 file systems, such as Btrfs, support compression, which is reported to
2462 nicely complement file deduplication that the daemon performs
2463 independently of the file system (@pxref{Invoking guix-daemon,
2466 Preferably, assign file systems a label so that you can easily and
2467 reliably refer to them in @code{file-system} declarations (@pxref{File
2468 Systems}). This is typically done using the @code{-L} option of
2469 @command{mkfs.ext4} and related commands. So, assuming the target root
2470 partition lives at @file{/dev/sda2}, a file system with the label
2471 @code{my-root} can be created with:
2474 mkfs.ext4 -L my-root /dev/sda2
2477 @cindex encrypted disk
2478 If you are instead planning to encrypt the root partition, you can use
2479 the Cryptsetup/LUKS utilities to do that (see @inlinefmtifelse{html,
2480 @uref{https://linux.die.net/man/8/cryptsetup, @code{man cryptsetup}},
2481 @code{man cryptsetup}} for more information). Assuming you want to
2482 store the root partition on @file{/dev/sda2}, the command sequence would
2483 be along these lines:
2486 cryptsetup luksFormat /dev/sda2
2487 cryptsetup open --type luks /dev/sda2 my-partition
2488 mkfs.ext4 -L my-root /dev/mapper/my-partition
2491 Once that is done, mount the target file system under @file{/mnt}
2492 with a command like (again, assuming @code{my-root} is the label of the
2496 mount LABEL=my-root /mnt
2499 Also mount any other file systems you would like to use on the target
2500 system relative to this path. If you have opted for @file{/boot/efi} as an
2501 EFI mount point for example, mount it at @file{/mnt/boot/efi} now so it is
2502 found by @code{guix system init} afterwards.
2504 Finally, if you plan to use one or more swap partitions (@pxref{Memory
2505 Concepts, swap space,, libc, The GNU C Library Reference Manual}), make
2506 sure to initialize them with @command{mkswap}. Assuming you have one
2507 swap partition on @file{/dev/sda3}, you would run:
2514 Alternatively, you may use a swap file. For example, assuming that in
2515 the new system you want to use the file @file{/swapfile} as a swap file,
2516 you would run@footnote{This example will work for many types of file
2517 systems (e.g., ext4). However, for copy-on-write file systems (e.g.,
2518 btrfs), the required steps may be different. For details, see the
2519 manual pages for @command{mkswap} and @command{swapon}.}:
2522 # This is 10 GiB of swap space. Adjust "count" to change the size.
2523 dd if=/dev/zero of=/mnt/swapfile bs=1MiB count=10240
2524 # For security, make the file readable and writable only by root.
2525 chmod 600 /mnt/swapfile
2526 mkswap /mnt/swapfile
2527 swapon /mnt/swapfile
2530 Note that if you have encrypted the root partition and created a swap
2531 file in its file system as described above, then the encryption also
2532 protects the swap file, just like any other file in that file system.
2534 @node Proceeding with the Installation
2535 @subsection Proceeding with the Installation
2537 With the target partitions ready and the target root mounted on
2538 @file{/mnt}, we're ready to go. First, run:
2541 herd start cow-store /mnt
2544 This makes @file{/gnu/store} copy-on-write, such that packages added to it
2545 during the installation phase are written to the target disk on @file{/mnt}
2546 rather than kept in memory. This is necessary because the first phase of
2547 the @command{guix system init} command (see below) entails downloads or
2548 builds to @file{/gnu/store} which, initially, is an in-memory file system.
2550 Next, you have to edit a file and
2551 provide the declaration of the operating system to be installed. To
2552 that end, the installation system comes with three text editors. We
2553 recommend GNU nano (@pxref{Top,,, nano, GNU nano Manual}), which
2554 supports syntax highlighting and parentheses matching; other editors
2555 include GNU Zile (an Emacs clone), and
2556 nvi (a clone of the original BSD @command{vi} editor).
2557 We strongly recommend storing that file on the target root file system, say,
2558 as @file{/mnt/etc/config.scm}. Failing to do that, you will have lost your
2559 configuration file once you have rebooted into the newly-installed system.
2561 @xref{Using the Configuration System}, for an overview of the
2562 configuration file. The example configurations discussed in that
2563 section are available under @file{/etc/configuration} in the
2564 installation image. Thus, to get started with a system configuration
2565 providing a graphical display server (a ``desktop'' system), you can run
2566 something along these lines:
2570 # cp /etc/configuration/desktop.scm /mnt/etc/config.scm
2571 # nano /mnt/etc/config.scm
2574 You should pay attention to what your configuration file contains, and
2579 Make sure the @code{bootloader-configuration} form refers to the target
2580 you want to install GRUB on. It should mention @code{grub-bootloader} if
2581 you are installing GRUB in the legacy way, or @code{grub-efi-bootloader}
2582 for newer UEFI systems. For legacy systems, the @code{target} field
2583 names a device, like @code{/dev/sda}; for UEFI systems it names a path
2584 to a mounted EFI partition, like @code{/boot/efi}; do make sure the path is
2585 currently mounted and a @code{file-system} entry is specified in your
2589 Be sure that your file system labels match the value of their respective
2590 @code{device} fields in your @code{file-system} configuration, assuming
2591 your @code{file-system} configuration uses the @code{file-system-label}
2592 procedure in its @code{device} field.
2595 If there are encrypted or RAID partitions, make sure to add a
2596 @code{mapped-devices} field to describe them (@pxref{Mapped Devices}).
2599 Once you are done preparing the configuration file, the new system must
2600 be initialized (remember that the target root file system is mounted
2604 guix system init /mnt/etc/config.scm /mnt
2608 This copies all the necessary files and installs GRUB on
2609 @file{/dev/sdX}, unless you pass the @option{--no-bootloader} option. For
2610 more information, @pxref{Invoking guix system}. This command may trigger
2611 downloads or builds of missing packages, which can take some time.
2613 Once that command has completed---and hopefully succeeded!---you can run
2614 @command{reboot} and boot into the new system. The @code{root} password
2615 in the new system is initially empty; other users' passwords need to be
2616 initialized by running the @command{passwd} command as @code{root},
2617 unless your configuration specifies otherwise
2618 (@pxref{user-account-password, user account passwords}).
2619 @xref{After System Installation}, for what's next!
2622 @node After System Installation
2623 @section After System Installation
2625 Success, you've now booted into Guix System! From then on, you can update the
2626 system whenever you want by running, say:
2630 sudo guix system reconfigure /etc/config.scm
2634 This builds a new system generation with the latest packages and services
2635 (@pxref{Invoking guix system}). We recommend doing that regularly so that
2636 your system includes the latest security updates (@pxref{Security Updates}).
2638 @c See <https://lists.gnu.org/archive/html/guix-devel/2019-01/msg00268.html>.
2640 @cindex sudo vs. @command{guix pull}
2641 Note that @command{sudo guix} runs your user's @command{guix} command and
2642 @emph{not} root's, because @command{sudo} leaves @env{PATH} unchanged. To
2643 explicitly run root's @command{guix}, type @command{sudo -i guix @dots{}}.
2645 The difference matters here, because @command{guix pull} updates
2646 the @command{guix} command and package definitions only for the user it is run
2647 as. This means that if you choose to use @command{guix system reconfigure} in
2648 root's login shell, you'll need to @command{guix pull} separately.
2651 Now, @pxref{Getting Started}, and
2652 join us on @code{#guix} on the Freenode IRC network or on
2653 @email{guix-devel@@gnu.org} to share your experience!
2656 @node Installing Guix in a VM
2657 @section Installing Guix in a Virtual Machine
2659 @cindex virtual machine, Guix System installation
2660 @cindex virtual private server (VPS)
2661 @cindex VPS (virtual private server)
2662 If you'd like to install Guix System in a virtual machine (VM) or on a
2663 virtual private server (VPS) rather than on your beloved machine, this
2666 To boot a @uref{https://qemu.org/,QEMU} VM for installing Guix System in a
2667 disk image, follow these steps:
2671 First, retrieve and decompress the Guix system installation image as
2672 described previously (@pxref{USB Stick and DVD Installation}).
2675 Create a disk image that will hold the installed system. To make a
2676 qcow2-formatted disk image, use the @command{qemu-img} command:
2679 qemu-img create -f qcow2 guix-system.img 50G
2682 The resulting file will be much smaller than 50 GB (typically less than
2683 1 MB), but it will grow as the virtualized storage device is filled up.
2686 Boot the USB installation image in an VM:
2689 qemu-system-x86_64 -m 1024 -smp 1 -enable-kvm \
2690 -nic user,model=virtio-net-pci -boot menu=on,order=d \
2691 -drive file=guix-system.img \
2692 -drive media=cdrom,file=guix-system-install-@value{VERSION}.@var{system}.iso
2695 @code{-enable-kvm} is optional, but significantly improves performance,
2696 @pxref{Running Guix in a VM}.
2699 You're now root in the VM, proceed with the installation process.
2700 @xref{Preparing for Installation}, and follow the instructions.
2703 Once installation is complete, you can boot the system that's on your
2704 @file{guix-system.img} image. @xref{Running Guix in a VM}, for how to do
2707 @node Building the Installation Image
2708 @section Building the Installation Image
2710 @cindex installation image
2711 The installation image described above was built using the @command{guix
2712 system} command, specifically:
2715 guix system image -t iso9660 gnu/system/install.scm
2718 Have a look at @file{gnu/system/install.scm} in the source tree,
2719 and see also @ref{Invoking guix system} for more information
2720 about the installation image.
2722 @section Building the Installation Image for ARM Boards
2724 Many ARM boards require a specific variant of the
2725 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot} bootloader.
2727 If you build a disk image and the bootloader is not available otherwise
2728 (on another boot drive etc), it's advisable to build an image that
2729 includes the bootloader, specifically:
2732 guix system image --system=armhf-linux -e '((@@ (gnu system install) os-with-u-boot) (@@ (gnu system install) installation-os) "A20-OLinuXino-Lime2")'
2735 @code{A20-OLinuXino-Lime2} is the name of the board. If you specify an invalid
2736 board, a list of possible boards will be printed.
2738 @c *********************************************************************
2739 @node Getting Started
2740 @chapter Getting Started
2742 Presumably, you've reached this section because either you have
2743 installed Guix on top of another distribution (@pxref{Installation}), or
2744 you've installed the standalone Guix System (@pxref{System
2745 Installation}). It's time for you to get started using Guix and this
2746 section aims to help you do that and give you a feel of what it's like.
2748 Guix is about installing software, so probably the first thing you'll
2749 want to do is to actually look for software. Let's say you're looking
2750 for a text editor, you can run:
2753 guix search text editor
2756 This command shows you a number of matching @dfn{packages}, each time
2757 showing the package's name, version, a description, and additional info.
2758 Once you've found out the one you want to use, let's say Emacs (ah ha!),
2759 you can go ahead and install it (run this command as a regular user,
2760 @emph{no need for root privileges}!):
2767 You've installed your first package, congrats! The package is now
2768 visible in your default @dfn{profile}, @file{$HOME/.guix-profile}---a
2769 profile is a directory containing installed packages.
2770 In the process, you've
2771 probably noticed that Guix downloaded pre-built binaries; or, if you
2772 explicitly chose to @emph{not} use pre-built binaries, then probably
2773 Guix is still building software (@pxref{Substitutes}, for more info).
2775 Unless you're using Guix System, the @command{guix install} command must
2776 have printed this hint:
2779 hint: Consider setting the necessary environment variables by running:
2781 GUIX_PROFILE="$HOME/.guix-profile"
2782 . "$GUIX_PROFILE/etc/profile"
2784 Alternately, see `guix package --search-paths -p "$HOME/.guix-profile"'.
2787 Indeed, you must now tell your shell where @command{emacs} and other
2788 programs installed with Guix are to be found. Pasting the two lines
2789 above will do just that: it will add
2790 @code{$HOME/.guix-profile/bin}---which is where the installed package
2791 is---to the @code{PATH} environment variable. You can paste these two
2792 lines in your shell so they take effect right away, but more importantly
2793 you should add them to @file{~/.bash_profile} (or equivalent file if you
2794 do not use Bash) so that environment variables are set next time you
2795 spawn a shell. You only need to do this once and other search paths
2796 environment variables will be taken care of similarly---e.g., if you
2797 eventually install @code{python} and Python libraries, @code{PYTHONPATH}
2800 You can go on installing packages at your will. To list installed
2804 guix package --list-installed
2807 To remove a package, you would unsurprisingly run @command{guix remove}.
2808 A distinguishing feature is the ability to @dfn{roll back} any operation
2809 you made---installation, removal, upgrade---by simply typing:
2812 guix package --roll-back
2815 This is because each operation is in fact a @dfn{transaction} that
2816 creates a new @dfn{generation}. These generations and the difference
2817 between them can be displayed by running:
2820 guix package --list-generations
2823 Now you know the basics of package management!
2825 @quotation Going further
2826 @xref{Package Management}, for more about package management. You may
2827 like @dfn{declarative} package management with @command{guix package
2828 --manifest}, managing separate @dfn{profiles} with @option{--profile},
2829 deleting old generations, collecting garbage, and other nifty features
2830 that will come in handy as you become more familiar with Guix. If you
2831 are a developer, @pxref{Development} for additional tools. And if
2832 you're curious, @pxref{Features}, to peek under the hood.
2835 Once you've installed a set of packages, you will want to periodically
2836 @emph{upgrade} them to the latest and greatest version. To do that, you
2837 will first pull the latest revision of Guix and its package collection:
2843 The end result is a new @command{guix} command, under
2844 @file{~/.config/guix/current/bin}. Unless you're on Guix System, the
2845 first time you run @command{guix pull}, be sure to follow the hint that
2846 the command prints and, similar to what we saw above, paste these two
2847 lines in your terminal and @file{.bash_profile}:
2850 GUIX_PROFILE="$HOME/.config/guix/current"
2851 . "$GUIX_PROFILE/etc/profile"
2855 You must also instruct your shell to point to this new @command{guix}:
2861 At this point, you're running a brand new Guix. You can thus go ahead
2862 and actually upgrade all the packages you previously installed:
2868 As you run this command, you will see that binaries are downloaded (or
2869 perhaps some packages are built), and eventually you end up with the
2870 upgraded packages. Should one of these upgraded packages not be to your
2871 liking, remember you can always roll back!
2873 You can display the exact revision of Guix you're currently using by
2880 The information it displays is @emph{all it takes to reproduce the exact
2881 same Guix}, be it at a different point in time or on a different
2884 @quotation Going further
2885 @xref{Invoking guix pull}, for more information. @xref{Channels}, on
2886 how to specify additional @dfn{channels} to pull packages from, how to
2887 replicate Guix, and more. You may also find @command{time-machine}
2888 handy (@pxref{Invoking guix time-machine}).
2891 If you installed Guix System, one of the first things you'll want to do
2892 is to upgrade your system. Once you've run @command{guix pull} to get
2893 the latest Guix, you can upgrade the system like this:
2896 sudo guix system reconfigure /etc/config.scm
2899 Upon completion, the system runs the latest versions of its software
2900 packages. When you eventually reboot, you'll notice a sub-menu in the
2901 bootloader that reads ``Old system generations'': it's what allows you
2902 to boot @emph{an older generation of your system}, should the latest
2903 generation be ``broken'' or otherwise unsatisfying. Just like for
2904 packages, you can always @emph{roll back} to a previous generation
2905 @emph{of the whole system}:
2908 sudo guix system roll-back
2911 There are many things you'll probably want to tweak on your system:
2912 adding new user accounts, adding new system services, fiddling with the
2913 configuration of those services, etc. The system configuration is
2914 @emph{entirely} described in the @file{/etc/config.scm} file.
2915 @xref{Using the Configuration System}, to learn how to change it.
2917 Now you know enough to get started!
2919 @quotation Resources
2920 The rest of this manual provides a reference for all things Guix. Here
2921 are some additional resources you may find useful:
2925 @xref{Top,,, guix-cookbook, The GNU Guix Cookbook}, for a list of
2926 ``how-to'' style of recipes for a variety of applications.
2929 The @uref{https://guix.gnu.org/guix-refcard.pdf, GNU Guix Reference
2930 Card} lists in two pages most of the commands and options you'll ever
2934 The web site contains @uref{https://guix.gnu.org/en/videos/,
2935 instructional videos} covering topics such as everyday use of Guix, how
2936 to get help, and how to become a contributor.
2939 @xref{Documentation}, to learn how to access documentation on your
2943 We hope you will enjoy Guix as much as the community enjoys building it!
2946 @c *********************************************************************
2947 @node Package Management
2948 @chapter Package Management
2951 The purpose of GNU Guix is to allow users to easily install, upgrade, and
2952 remove software packages, without having to know about their build
2953 procedures or dependencies. Guix also goes beyond this obvious set of
2956 This chapter describes the main features of Guix, as well as the
2957 package management tools it provides. Along with the command-line
2958 interface described below (@pxref{Invoking guix package, @code{guix
2959 package}}), you may also use the Emacs-Guix interface (@pxref{Top,,,
2960 emacs-guix, The Emacs-Guix Reference Manual}), after installing
2961 @code{emacs-guix} package (run @kbd{M-x guix-help} command to start
2965 guix install emacs-guix
2969 * Features:: How Guix will make your life brighter.
2970 * Invoking guix package:: Package installation, removal, etc.
2971 * Substitutes:: Downloading pre-built binaries.
2972 * Packages with Multiple Outputs:: Single source package, multiple outputs.
2973 * Invoking guix gc:: Running the garbage collector.
2974 * Invoking guix pull:: Fetching the latest Guix and distribution.
2975 * Invoking guix time-machine:: Running an older revision of Guix.
2976 * Inferiors:: Interacting with another revision of Guix.
2977 * Invoking guix describe:: Display information about your Guix revision.
2978 * Invoking guix archive:: Exporting and importing store files.
2984 Here we assume you've already made your first steps with Guix
2985 (@pxref{Getting Started}) and would like to get an overview about what's
2986 going on under the hood.
2988 When using Guix, each package ends up in the @dfn{package store}, in its
2989 own directory---something that resembles
2990 @file{/gnu/store/xxx-package-1.2}, where @code{xxx} is a base32 string.
2992 Instead of referring to these directories, users have their own
2993 @dfn{profile}, which points to the packages that they actually want to
2994 use. These profiles are stored within each user's home directory, at
2995 @code{$HOME/.guix-profile}.
2997 For example, @code{alice} installs GCC 4.7.2. As a result,
2998 @file{/home/alice/.guix-profile/bin/gcc} points to
2999 @file{/gnu/store/@dots{}-gcc-4.7.2/bin/gcc}. Now, on the same machine,
3000 @code{bob} had already installed GCC 4.8.0. The profile of @code{bob}
3001 simply continues to point to
3002 @file{/gnu/store/@dots{}-gcc-4.8.0/bin/gcc}---i.e., both versions of GCC
3003 coexist on the same system without any interference.
3005 The @command{guix package} command is the central tool to manage
3006 packages (@pxref{Invoking guix package}). It operates on the per-user
3007 profiles, and can be used @emph{with normal user privileges}.
3009 @cindex transactions
3010 The command provides the obvious install, remove, and upgrade
3011 operations. Each invocation is actually a @emph{transaction}: either
3012 the specified operation succeeds, or nothing happens. Thus, if the
3013 @command{guix package} process is terminated during the transaction,
3014 or if a power outage occurs during the transaction, then the user's
3015 profile remains in its previous state, and remains usable.
3017 In addition, any package transaction may be @emph{rolled back}. So, if,
3018 for example, an upgrade installs a new version of a package that turns
3019 out to have a serious bug, users may roll back to the previous instance
3020 of their profile, which was known to work well. Similarly, the global
3021 system configuration on Guix is subject to
3022 transactional upgrades and roll-back
3023 (@pxref{Using the Configuration System}).
3025 All packages in the package store may be @emph{garbage-collected}.
3026 Guix can determine which packages are still referenced by user
3027 profiles, and remove those that are provably no longer referenced
3028 (@pxref{Invoking guix gc}). Users may also explicitly remove old
3029 generations of their profile so that the packages they refer to can be
3032 @cindex reproducibility
3033 @cindex reproducible builds
3034 Guix takes a @dfn{purely functional} approach to package
3035 management, as described in the introduction (@pxref{Introduction}).
3036 Each @file{/gnu/store} package directory name contains a hash of all the
3037 inputs that were used to build that package---compiler, libraries, build
3038 scripts, etc. This direct correspondence allows users to make sure a
3039 given package installation matches the current state of their
3040 distribution. It also helps maximize @dfn{build reproducibility}:
3041 thanks to the isolated build environments that are used, a given build
3042 is likely to yield bit-identical files when performed on different
3043 machines (@pxref{Invoking guix-daemon, container}).
3046 This foundation allows Guix to support @dfn{transparent binary/source
3047 deployment}. When a pre-built binary for a @file{/gnu/store} item is
3048 available from an external source---a @dfn{substitute}, Guix just
3049 downloads it and unpacks it;
3050 otherwise, it builds the package from source, locally
3051 (@pxref{Substitutes}). Because build results are usually bit-for-bit
3052 reproducible, users do not have to trust servers that provide
3053 substitutes: they can force a local build and @emph{challenge} providers
3054 (@pxref{Invoking guix challenge}).
3056 Control over the build environment is a feature that is also useful for
3057 developers. The @command{guix environment} command allows developers of
3058 a package to quickly set up the right development environment for their
3059 package, without having to manually install the dependencies of the
3060 package into their profile (@pxref{Invoking guix environment}).
3062 @cindex replication, of software environments
3063 @cindex provenance tracking, of software artifacts
3064 All of Guix and its package definitions is version-controlled, and
3065 @command{guix pull} allows you to ``travel in time'' on the history of Guix
3066 itself (@pxref{Invoking guix pull}). This makes it possible to replicate a
3067 Guix instance on a different machine or at a later point in time, which in
3068 turn allows you to @emph{replicate complete software environments}, while
3069 retaining precise @dfn{provenance tracking} of the software.
3071 @node Invoking guix package
3072 @section Invoking @command{guix package}
3074 @cindex installing packages
3075 @cindex removing packages
3076 @cindex package installation
3077 @cindex package removal
3079 The @command{guix package} command is the tool that allows users to
3080 install, upgrade, and remove packages, as well as rolling back to
3081 previous configurations. These operations work on a user
3082 @dfn{profile}---a directory of installed packages. Each user has a
3083 default profile in @file{$HOME/.guix-profile}.
3084 The command operates only on the user's own profile,
3085 and works with normal user privileges (@pxref{Features}). Its syntax
3089 guix package @var{options}
3092 @cindex transactions
3093 Primarily, @var{options} specifies the operations to be performed during
3094 the transaction. Upon completion, a new profile is created, but
3095 previous @dfn{generations} of the profile remain available, should the user
3098 For example, to remove @code{lua} and install @code{guile} and
3099 @code{guile-cairo} in a single transaction:
3102 guix package -r lua -i guile guile-cairo
3105 @cindex aliases, for @command{guix package}
3106 For your convenience, we also provide the following aliases:
3110 @command{guix search} is an alias for @command{guix package -s},
3112 @command{guix install} is an alias for @command{guix package -i},
3114 @command{guix remove} is an alias for @command{guix package -r},
3116 @command{guix upgrade} is an alias for @command{guix package -u},
3118 and @command{guix show} is an alias for @command{guix package --show=}.
3121 These aliases are less expressive than @command{guix package} and provide
3122 fewer options, so in some cases you'll probably want to use @command{guix
3125 @command{guix package} also supports a @dfn{declarative approach}
3126 whereby the user specifies the exact set of packages to be available and
3127 passes it @i{via} the @option{--manifest} option
3128 (@pxref{profile-manifest, @option{--manifest}}).
3131 For each user, a symlink to the user's default profile is automatically
3132 created in @file{$HOME/.guix-profile}. This symlink always points to the
3133 current generation of the user's default profile. Thus, users can add
3134 @file{$HOME/.guix-profile/bin} to their @env{PATH} environment
3135 variable, and so on.
3136 @cindex search paths
3137 If you are not using Guix System, consider adding the
3138 following lines to your @file{~/.bash_profile} (@pxref{Bash Startup
3139 Files,,, bash, The GNU Bash Reference Manual}) so that newly-spawned
3140 shells get all the right environment variable definitions:
3143 GUIX_PROFILE="$HOME/.guix-profile" ; \
3144 source "$GUIX_PROFILE/etc/profile"
3147 In a multi-user setup, user profiles are stored in a place registered as
3148 a @dfn{garbage-collector root}, which @file{$HOME/.guix-profile} points
3149 to (@pxref{Invoking guix gc}). That directory is normally
3150 @code{@var{localstatedir}/guix/profiles/per-user/@var{user}}, where
3151 @var{localstatedir} is the value passed to @code{configure} as
3152 @option{--localstatedir}, and @var{user} is the user name. The
3153 @file{per-user} directory is created when @command{guix-daemon} is
3154 started, and the @var{user} sub-directory is created by @command{guix
3157 The @var{options} can be among the following:
3161 @item --install=@var{package} @dots{}
3162 @itemx -i @var{package} @dots{}
3163 Install the specified @var{package}s.
3165 Each @var{package} may specify either a simple package name, such as
3166 @code{guile}, or a package name followed by an at-sign and version number,
3167 such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
3168 case, the newest version prefixed by @code{1.8} is selected).
3170 If no version number is specified, the
3171 newest available version will be selected. In addition, @var{package}
3172 may contain a colon, followed by the name of one of the outputs of the
3173 package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
3174 (@pxref{Packages with Multiple Outputs}). Packages with a corresponding
3175 name (and optionally version) are searched for among the GNU
3176 distribution modules (@pxref{Package Modules}).
3178 @cindex propagated inputs
3179 Sometimes packages have @dfn{propagated inputs}: these are dependencies
3180 that automatically get installed along with the required package
3181 (@pxref{package-propagated-inputs, @code{propagated-inputs} in
3182 @code{package} objects}, for information about propagated inputs in
3183 package definitions).
3185 @anchor{package-cmd-propagated-inputs}
3186 An example is the GNU MPC library: its C header files refer to those of
3187 the GNU MPFR library, which in turn refer to those of the GMP library.
3188 Thus, when installing MPC, the MPFR and GMP libraries also get installed
3189 in the profile; removing MPC also removes MPFR and GMP---unless they had
3190 also been explicitly installed by the user.
3192 Besides, packages sometimes rely on the definition of environment
3193 variables for their search paths (see explanation of
3194 @option{--search-paths} below). Any missing or possibly incorrect
3195 environment variable definitions are reported here.
3197 @item --install-from-expression=@var{exp}
3199 Install the package @var{exp} evaluates to.
3201 @var{exp} must be a Scheme expression that evaluates to a
3202 @code{<package>} object. This option is notably useful to disambiguate
3203 between same-named variants of a package, with expressions such as
3204 @code{(@@ (gnu packages base) guile-final)}.
3206 Note that this option installs the first output of the specified
3207 package, which may be insufficient when needing a specific output of a
3208 multiple-output package.
3210 @item --install-from-file=@var{file}
3211 @itemx -f @var{file}
3212 Install the package that the code within @var{file} evaluates to.
3214 As an example, @var{file} might contain a definition like this
3215 (@pxref{Defining Packages}):
3218 @include package-hello.scm
3221 Developers may find it useful to include such a @file{guix.scm} file
3222 in the root of their project source tree that can be used to test
3223 development snapshots and create reproducible development environments
3224 (@pxref{Invoking guix environment}).
3226 The @var{file} may also contain a JSON representation of one or more
3227 package definitions. Running @code{guix package -f} on
3228 @file{hello.json} with the following contents would result in installing
3229 the package @code{greeter} after building @code{myhello}:
3232 @verbatiminclude package-hello.json
3235 @item --remove=@var{package} @dots{}
3236 @itemx -r @var{package} @dots{}
3237 Remove the specified @var{package}s.
3239 As for @option{--install}, each @var{package} may specify a version number
3240 and/or output name in addition to the package name. For instance,
3241 @samp{-r glibc:debug} would remove the @code{debug} output of
3244 @item --upgrade[=@var{regexp} @dots{}]
3245 @itemx -u [@var{regexp} @dots{}]
3246 @cindex upgrading packages
3247 Upgrade all the installed packages. If one or more @var{regexp}s are
3248 specified, upgrade only installed packages whose name matches a
3249 @var{regexp}. Also see the @option{--do-not-upgrade} option below.
3251 Note that this upgrades package to the latest version of packages found
3252 in the distribution currently installed. To update your distribution,
3253 you should regularly run @command{guix pull} (@pxref{Invoking guix
3256 @cindex package transformations, upgrades
3257 When upgrading, package transformations that were originally applied
3258 when creating the profile are automatically re-applied (@pxref{Package
3259 Transformation Options}). For example, assume you first installed Emacs
3260 from the tip of its development branch with:
3263 guix install emacs-next --with-branch=emacs-next=master
3266 Next time you run @command{guix upgrade}, Guix will again pull the tip
3267 of the Emacs development branch and build @code{emacs-next} from that
3270 Note that transformation options such as @option{--with-branch} and
3271 @option{--with-source} depend on external state; it is up to you to
3272 ensure that they work as expected. You can also discard a
3273 transformations that apply to a package by running:
3276 guix install @var{package}
3279 @item --do-not-upgrade[=@var{regexp} @dots{}]
3280 When used together with the @option{--upgrade} option, do @emph{not}
3281 upgrade any packages whose name matches a @var{regexp}. For example, to
3282 upgrade all packages in the current profile except those containing the
3283 substring ``emacs'':
3286 $ guix package --upgrade . --do-not-upgrade emacs
3289 @item @anchor{profile-manifest}--manifest=@var{file}
3290 @itemx -m @var{file}
3291 @cindex profile declaration
3292 @cindex profile manifest
3293 Create a new generation of the profile from the manifest object
3294 returned by the Scheme code in @var{file}. This option can be repeated
3295 several times, in which case the manifests are concatenated.
3297 This allows you to @emph{declare} the profile's contents rather than
3298 constructing it through a sequence of @option{--install} and similar
3299 commands. The advantage is that @var{file} can be put under version
3300 control, copied to different machines to reproduce the same profile, and
3303 @c FIXME: Add reference to (guix profile) documentation when available.
3304 @var{file} must return a @dfn{manifest} object, which is roughly a list
3307 @findex packages->manifest
3309 (use-package-modules guile emacs)
3314 ;; Use a specific package output.
3315 (list guile-2.0 "debug")))
3318 @findex specifications->manifest
3319 In this example we have to know which modules define the @code{emacs}
3320 and @code{guile-2.0} variables to provide the right
3321 @code{use-package-modules} line, which can be cumbersome. We can
3322 instead provide regular package specifications and let
3323 @code{specifications->manifest} look up the corresponding package
3327 (specifications->manifest
3328 '("emacs" "guile@@2.2" "guile@@2.2:debug"))
3331 @xref{export-manifest, @option{--export-manifest}}, to learn how to
3332 obtain a manifest file from an existing profile.
3335 @cindex rolling back
3336 @cindex undoing transactions
3337 @cindex transactions, undoing
3338 Roll back to the previous @dfn{generation} of the profile---i.e., undo
3339 the last transaction.
3341 When combined with options such as @option{--install}, roll back occurs
3342 before any other actions.
3344 When rolling back from the first generation that actually contains
3345 installed packages, the profile is made to point to the @dfn{zeroth
3346 generation}, which contains no files apart from its own metadata.
3348 After having rolled back, installing, removing, or upgrading packages
3349 overwrites previous future generations. Thus, the history of the
3350 generations in a profile is always linear.
3352 @item --switch-generation=@var{pattern}
3353 @itemx -S @var{pattern}
3355 Switch to a particular generation defined by @var{pattern}.
3357 @var{pattern} may be either a generation number or a number prefixed
3358 with ``+'' or ``-''. The latter means: move forward/backward by a
3359 specified number of generations. For example, if you want to return to
3360 the latest generation after @option{--roll-back}, use
3361 @option{--switch-generation=+1}.
3363 The difference between @option{--roll-back} and
3364 @option{--switch-generation=-1} is that @option{--switch-generation} will
3365 not make a zeroth generation, so if a specified generation does not
3366 exist, the current generation will not be changed.
3368 @item --search-paths[=@var{kind}]
3369 @cindex search paths
3370 Report environment variable definitions, in Bash syntax, that may be
3371 needed in order to use the set of installed packages. These environment
3372 variables are used to specify @dfn{search paths} for files used by some
3373 of the installed packages.
3375 For example, GCC needs the @env{CPATH} and @env{LIBRARY_PATH}
3376 environment variables to be defined so it can look for headers and
3377 libraries in the user's profile (@pxref{Environment Variables,,, gcc,
3378 Using the GNU Compiler Collection (GCC)}). If GCC and, say, the C
3379 library are installed in the profile, then @option{--search-paths} will
3380 suggest setting these variables to @file{@var{profile}/include} and
3381 @file{@var{profile}/lib}, respectively.
3383 The typical use case is to define these environment variables in the
3387 $ eval `guix package --search-paths`
3390 @var{kind} may be one of @code{exact}, @code{prefix}, or @code{suffix},
3391 meaning that the returned environment variable definitions will either
3392 be exact settings, or prefixes or suffixes of the current value of these
3393 variables. When omitted, @var{kind} defaults to @code{exact}.
3395 This option can also be used to compute the @emph{combined} search paths
3396 of several profiles. Consider this example:
3399 $ guix package -p foo -i guile
3400 $ guix package -p bar -i guile-json
3401 $ guix package -p foo -p bar --search-paths
3404 The last command above reports about the @env{GUILE_LOAD_PATH}
3405 variable, even though, taken individually, neither @file{foo} nor
3406 @file{bar} would lead to that recommendation.
3409 @cindex profile, choosing
3410 @item --profile=@var{profile}
3411 @itemx -p @var{profile}
3412 Use @var{profile} instead of the user's default profile.
3414 @var{profile} must be the name of a file that will be created upon
3415 completion. Concretely, @var{profile} will be a mere symbolic link
3416 (``symlink'') pointing to the actual profile where packages are
3420 $ guix install hello -p ~/code/my-profile
3422 $ ~/code/my-profile/bin/hello
3426 All it takes to get rid of the profile is to remove this symlink and its
3427 siblings that point to specific generations:
3430 $ rm ~/code/my-profile ~/code/my-profile-*-link
3433 @item --list-profiles
3434 List all the user's profiles:
3437 $ guix package --list-profiles
3438 /home/charlie/.guix-profile
3439 /home/charlie/code/my-profile
3440 /home/charlie/code/devel-profile
3441 /home/charlie/tmp/test
3444 When running as root, list all the profiles of all the users.
3446 @cindex collisions, in a profile
3447 @cindex colliding packages in profiles
3448 @cindex profile collisions
3449 @item --allow-collisions
3450 Allow colliding packages in the new profile. Use at your own risk!
3452 By default, @command{guix package} reports as an error @dfn{collisions}
3453 in the profile. Collisions happen when two or more different versions
3454 or variants of a given package end up in the profile.
3457 Use the bootstrap Guile to build the profile. This option is only
3458 useful to distribution developers.
3462 In addition to these actions, @command{guix package} supports the
3463 following options to query the current state of a profile, or the
3464 availability of packages:
3468 @item --search=@var{regexp}
3469 @itemx -s @var{regexp}
3470 @anchor{guix-search}
3471 @cindex searching for packages
3472 List the available packages whose name, synopsis, or description matches
3473 @var{regexp} (in a case-insensitive fashion), sorted by relevance.
3474 Print all the metadata of matching packages in
3475 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils,
3476 GNU recutils manual}).
3478 This allows specific fields to be extracted using the @command{recsel}
3479 command, for instance:
3482 $ guix package -s malloc | recsel -p name,version,relevance
3496 Similarly, to show the name of all the packages available under the
3497 terms of the GNU@tie{}LGPL version 3:
3500 $ guix package -s "" | recsel -p name -e 'license ~ "LGPL 3"'
3507 It is also possible to refine search results using several @code{-s} flags to
3508 @command{guix package}, or several arguments to @command{guix search}. For
3509 example, the following command returns a list of board games (this time using
3510 the @command{guix search} alias):
3513 $ guix search '\<board\>' game | recsel -p name
3518 If we were to omit @code{-s game}, we would also get software packages
3519 that deal with printed circuit boards; removing the angle brackets
3520 around @code{board} would further add packages that have to do with
3523 And now for a more elaborate example. The following command searches
3524 for cryptographic libraries, filters out Haskell, Perl, Python, and Ruby
3525 libraries, and prints the name and synopsis of the matching packages:
3528 $ guix search crypto library | \
3529 recsel -e '! (name ~ "^(ghc|perl|python|ruby)")' -p name,synopsis
3533 @xref{Selection Expressions,,, recutils, GNU recutils manual}, for more
3534 information on @dfn{selection expressions} for @code{recsel -e}.
3536 @item --show=@var{package}
3537 Show details about @var{package}, taken from the list of available packages, in
3538 @code{recutils} format (@pxref{Top, GNU recutils databases,, recutils, GNU
3542 $ guix package --show=python | recsel -p name,version
3550 You may also specify the full name of a package to only get details about a
3551 specific version of it (this time using the @command{guix show} alias):
3553 $ guix show python@@3.4 | recsel -p name,version
3560 @item --list-installed[=@var{regexp}]
3561 @itemx -I [@var{regexp}]
3562 List the currently installed packages in the specified profile, with the
3563 most recently installed packages shown last. When @var{regexp} is
3564 specified, list only installed packages whose name matches @var{regexp}.
3566 For each installed package, print the following items, separated by
3567 tabs: the package name, its version string, the part of the package that
3568 is installed (for instance, @code{out} for the default output,
3569 @code{include} for its headers, etc.), and the path of this package in
3572 @item --list-available[=@var{regexp}]
3573 @itemx -A [@var{regexp}]
3574 List packages currently available in the distribution for this system
3575 (@pxref{GNU Distribution}). When @var{regexp} is specified, list only
3576 available packages whose name matches @var{regexp}.
3578 For each package, print the following items separated by tabs: its name,
3579 its version string, the parts of the package (@pxref{Packages with
3580 Multiple Outputs}), and the source location of its definition.
3582 @item --list-generations[=@var{pattern}]
3583 @itemx -l [@var{pattern}]
3585 Return a list of generations along with their creation dates; for each
3586 generation, show the installed packages, with the most recently
3587 installed packages shown last. Note that the zeroth generation is never
3590 For each installed package, print the following items, separated by
3591 tabs: the name of a package, its version string, the part of the package
3592 that is installed (@pxref{Packages with Multiple Outputs}), and the
3593 location of this package in the store.
3595 When @var{pattern} is used, the command returns only matching
3596 generations. Valid patterns include:
3599 @item @emph{Integers and comma-separated integers}. Both patterns denote
3600 generation numbers. For instance, @option{--list-generations=1} returns
3603 And @option{--list-generations=1,8,2} outputs three generations in the
3604 specified order. Neither spaces nor trailing commas are allowed.
3606 @item @emph{Ranges}. @option{--list-generations=2..9} prints the
3607 specified generations and everything in between. Note that the start of
3608 a range must be smaller than its end.
3610 It is also possible to omit the endpoint. For example,
3611 @option{--list-generations=2..}, returns all generations starting from the
3614 @item @emph{Durations}. You can also get the last @emph{N}@tie{}days, weeks,
3615 or months by passing an integer along with the first letter of the
3616 duration. For example, @option{--list-generations=20d} lists generations
3617 that are up to 20 days old.
3620 @item --delete-generations[=@var{pattern}]
3621 @itemx -d [@var{pattern}]
3622 When @var{pattern} is omitted, delete all generations except the current
3625 This command accepts the same patterns as @option{--list-generations}.
3626 When @var{pattern} is specified, delete the matching generations. When
3627 @var{pattern} specifies a duration, generations @emph{older} than the
3628 specified duration match. For instance, @option{--delete-generations=1m}
3629 deletes generations that are more than one month old.
3631 If the current generation matches, it is @emph{not} deleted. Also, the
3632 zeroth generation is never deleted.
3634 Note that deleting generations prevents rolling back to them.
3635 Consequently, this command must be used with care.
3637 @cindex manifest, exporting
3638 @anchor{export-manifest}
3639 @item --export-manifest
3640 Write to standard output a manifest suitable for @option{--manifest}
3641 corresponding to the chosen profile(s).
3643 This option is meant to help you migrate from the ``imperative''
3644 operating mode---running @command{guix install}, @command{guix upgrade},
3645 etc.---to the declarative mode that @option{--manifest} offers.
3647 Be aware that the resulting manifest @emph{approximates} what your
3648 profile actually contains; for instance, depending on how your profile
3649 was created, it can refer to packages or package versions that are not
3650 exactly what you specified.
3652 Keep in mind that a manifest is purely symbolic: it only contains
3653 package names and possibly versions, and their meaning varies over time.
3654 If you wish to ``pin'' channels to the revisions that were used to build
3655 the profile(s), see @option{--export-channels} below.
3657 @cindex pinning, channel revisions of a profile
3658 @item --export-channels
3659 Write to standard output the list of channels used by the chosen
3660 profile(s), in a format suitable for @command{guix pull --channels} or
3661 @command{guix time-machine --channels} (@pxref{Channels}).
3663 Together with @option{--export-manifest}, this option provides
3664 information allowing you to replicate the current profile
3665 (@pxref{Replicating Guix}).
3667 However, note that the output of this command @emph{approximates} what
3668 was actually used to build this profile. In particular, a single
3669 profile might have been built from several different revisions of the
3670 same channel. In that case, @option{--export-manifest} chooses the last
3671 one and writes the list of other revisions in a comment. If you really
3672 need to pick packages from different channel revisions, you can use
3673 inferiors in your manifest to do so (@pxref{Inferiors}).
3675 Together with @option{--export-manifest}, this is a good starting point
3676 if you are willing to migrate from the ``imperative'' model to the fully
3677 declarative model consisting of a manifest file along with a channels
3678 file pinning the exact channel revision(s) you want.
3681 Finally, since @command{guix package} may actually start build
3682 processes, it supports all the common build options (@pxref{Common Build
3683 Options}). It also supports package transformation options, such as
3684 @option{--with-source}, and preserves them across upgrades
3685 (@pxref{Package Transformation Options}).
3688 @section Substitutes
3691 @cindex pre-built binaries
3692 Guix supports transparent source/binary deployment, which means that it
3693 can either build things locally, or download pre-built items from a
3694 server, or both. We call these pre-built items @dfn{substitutes}---they
3695 are substitutes for local build results. In many cases, downloading a
3696 substitute is much faster than building things locally.
3698 Substitutes can be anything resulting from a derivation build
3699 (@pxref{Derivations}). Of course, in the common case, they are
3700 pre-built package binaries, but source tarballs, for instance, which
3701 also result from derivation builds, can be available as substitutes.
3704 * Official Substitute Server:: One particular source of substitutes.
3705 * Substitute Server Authorization:: How to enable or disable substitutes.
3706 * Getting Substitutes from Other Servers:: Substitute diversity.
3707 * Substitute Authentication:: How Guix verifies substitutes.
3708 * Proxy Settings:: How to get substitutes via proxy.
3709 * Substitution Failure:: What happens when substitution fails.
3710 * On Trusting Binaries:: How can you trust that binary blob?
3713 @node Official Substitute Server
3714 @subsection Official Substitute Server
3717 The @code{@value{SUBSTITUTE-SERVER}} server is a front-end to an official build farm
3718 that builds packages from Guix continuously for some
3719 architectures, and makes them available as substitutes. This is the
3720 default source of substitutes; it can be overridden by passing the
3721 @option{--substitute-urls} option either to @command{guix-daemon}
3722 (@pxref{daemon-substitute-urls,, @code{guix-daemon --substitute-urls}})
3723 or to client tools such as @command{guix package}
3724 (@pxref{client-substitute-urls,, client @option{--substitute-urls}
3727 Substitute URLs can be either HTTP or HTTPS.
3728 HTTPS is recommended because communications are encrypted; conversely,
3729 using HTTP makes all communications visible to an eavesdropper, who
3730 could use the information gathered to determine, for instance, whether
3731 your system has unpatched security vulnerabilities.
3733 Substitutes from the official build farm are enabled by default when
3734 using Guix System (@pxref{GNU Distribution}). However,
3735 they are disabled by default when using Guix on a foreign distribution,
3736 unless you have explicitly enabled them via one of the recommended
3737 installation steps (@pxref{Installation}). The following paragraphs
3738 describe how to enable or disable substitutes for the official build
3739 farm; the same procedure can also be used to enable substitutes for any
3740 other substitute server.
3742 @node Substitute Server Authorization
3743 @subsection Substitute Server Authorization
3746 @cindex substitutes, authorization thereof
3747 @cindex access control list (ACL), for substitutes
3748 @cindex ACL (access control list), for substitutes
3749 To allow Guix to download substitutes from @code{@value{SUBSTITUTE-SERVER}} or a
3751 must add its public key to the access control list (ACL) of archive
3752 imports, using the @command{guix archive} command (@pxref{Invoking guix
3753 archive}). Doing so implies that you trust @code{@value{SUBSTITUTE-SERVER}} to not
3754 be compromised and to serve genuine substitutes.
3757 If you are using Guix System, you can skip this section: Guix System
3758 authorizes substitutes from @code{@value{SUBSTITUTE-SERVER}} by default.
3761 The public key for @code{@value{SUBSTITUTE-SERVER}} is installed along with Guix, in
3762 @code{@var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub}, where @var{prefix} is
3763 the installation prefix of Guix. If you installed Guix from source,
3764 make sure you checked the GPG signature of
3765 @file{guix-@value{VERSION}.tar.gz}, which contains this public key file.
3766 Then, you can run something like this:
3769 # guix archive --authorize < @var{prefix}/share/guix/@value{SUBSTITUTE-SERVER}.pub
3772 Once this is in place, the output of a command like @code{guix build}
3773 should change from something like:
3776 $ guix build emacs --dry-run
3777 The following derivations would be built:
3778 /gnu/store/yr7bnx8xwcayd6j95r2clmkdl1qh688w-emacs-24.3.drv
3779 /gnu/store/x8qsh1hlhgjx6cwsjyvybnfv2i37z23w-dbus-1.6.4.tar.gz.drv
3780 /gnu/store/1ixwp12fl950d15h2cj11c73733jay0z-alsa-lib-1.0.27.1.tar.bz2.drv
3781 /gnu/store/nlma1pw0p603fpfiqy7kn4zm105r5dmw-util-linux-2.21.drv
3789 $ guix build emacs --dry-run
3790 112.3 MB would be downloaded:
3791 /gnu/store/pk3n22lbq6ydamyymqkkz7i69wiwjiwi-emacs-24.3
3792 /gnu/store/2ygn4ncnhrpr61rssa6z0d9x22si0va3-libjpeg-8d
3793 /gnu/store/71yz6lgx4dazma9dwn2mcjxaah9w77jq-cairo-1.12.16
3794 /gnu/store/7zdhgp0n1518lvfn8mb96sxqfmvqrl7v-libxrender-0.9.7
3799 The text changed from ``The following derivations would be built'' to
3800 ``112.3 MB would be downloaded''. This indicates that substitutes from
3801 @code{@value{SUBSTITUTE-SERVER}} are usable and will be downloaded, when
3802 possible, for future builds.
3804 @cindex substitutes, how to disable
3805 The substitute mechanism can be disabled globally by running
3806 @code{guix-daemon} with @option{--no-substitutes} (@pxref{Invoking
3807 guix-daemon}). It can also be disabled temporarily by passing the
3808 @option{--no-substitutes} option to @command{guix package},
3809 @command{guix build}, and other command-line tools.
3811 @node Getting Substitutes from Other Servers
3812 @subsection Getting Substitutes from Other Servers
3814 @cindex substitute servers, adding more
3815 Guix can look up and fetch substitutes from several servers. This is
3816 useful when you are using packages from additional channels for which
3817 the official server does not have substitutes but another server
3818 provides them. Another situation where this is useful is when you would
3819 prefer to download from your organization's substitute server, resorting
3820 to the official server only as a fallback or dismissing it altogether.
3822 You can give Guix a list of substitute server URLs and it will check
3823 them in the specified order. You also need to explicitly authorize the
3824 public keys of substitute servers to instruct Guix to accept the
3825 substitutes they sign.
3827 On Guix System, this is achieved by modifying the configuration of the
3828 @code{guix} service. Since the @code{guix} service is part of the
3829 default lists of services, @code{%base-services} and
3830 @code{%desktop-services}, you can use @code{modify-services} to change
3831 its configuration and add the URLs and substitute keys that you want
3832 (@pxref{Service Reference, @code{modify-services}}).
3834 As an example, suppose you want to fetch substitutes from
3835 @code{guix.example.org} and to authorize the signing key of that server,
3836 in addition to the default @code{@value{SUBSTITUTE-SERVER}}. The
3837 resulting operating system configuration will look something like:
3843 ;; Assume we're starting from '%desktop-services'. Replace it
3844 ;; with the list of services you're actually using.
3845 (modify-services %desktop-services
3846 (guix-service-type config =>
3850 (append (list "https://guix.example.org")
3851 %default-substitute-urls))
3853 (append (list (local-file "./key.pub"))
3854 %default-authorized-guix-keys)))))))
3857 This assumes that the file @file{key.pub} contains the signing key of
3858 @code{guix.example.org}. With this change in place in your operating
3859 system configuration file (say @file{/etc/config.scm}), you can
3860 reconfigure and restart the @code{guix-daemon} service or reboot so the
3861 changes take effect:
3864 $ sudo guix system reconfigure /etc/config.scm
3865 $ sudo herd restart guix-daemon
3868 If you're running Guix on a ``foreign distro'', you would instead take
3869 the following steps to get substitutes from additional servers:
3873 Edit the service configuration file for @code{guix-daemon}; when using
3874 systemd, this is normally
3875 @file{/etc/systemd/system/guix-daemon.service}. Add the
3876 @option{--substitute-urls} option on the @command{guix-daemon} command
3877 line and list the URLs of interest (@pxref{daemon-substitute-urls,
3878 @code{guix-daemon --substitute-urls}}):
3881 @dots{} --substitute-urls='https://guix.example.org https://@value{SUBSTITUTE-SERVER}'
3885 Restart the daemon. For systemd, it goes like this:
3888 systemctl daemon-reload
3889 systemctl restart guix-daemon.service
3893 Authorize the key of the new server (@pxref{Invoking guix archive}):
3896 guix archive --authorize < key.pub
3899 Again this assumes @file{key.pub} contains the public key that
3900 @code{guix.example.org} uses to sign substitutes.
3903 Now you're all set! Substitutes will be preferably taken from
3904 @code{https://guix.example.org}, using @code{@value{SUBSTITUTE-SERVER}}
3905 as a fallback. Of course you can list as many substitute servers as you
3906 like, with the caveat that substitute lookup can be slowed down if too
3907 many servers need to be contacted.
3909 Note that there are also situations where one may want to add the URL of
3910 a substitute server @emph{without} authorizing its key.
3911 @xref{Substitute Authentication}, to understand this fine point.
3913 @node Substitute Authentication
3914 @subsection Substitute Authentication
3916 @cindex digital signatures
3917 Guix detects and raises an error when attempting to use a substitute
3918 that has been tampered with. Likewise, it ignores substitutes that are
3919 not signed, or that are not signed by one of the keys listed in the ACL.
3921 There is one exception though: if an unauthorized server provides
3922 substitutes that are @emph{bit-for-bit identical} to those provided by
3923 an authorized server, then the unauthorized server becomes eligible for
3924 downloads. For example, assume we have chosen two substitute servers
3928 --substitute-urls="https://a.example.org https://b.example.org"
3932 @cindex reproducible builds
3933 If the ACL contains only the key for @samp{b.example.org}, and if
3934 @samp{a.example.org} happens to serve the @emph{exact same} substitutes,
3935 then Guix will download substitutes from @samp{a.example.org} because it
3936 comes first in the list and can be considered a mirror of
3937 @samp{b.example.org}. In practice, independent build machines usually
3938 produce the same binaries, thanks to bit-reproducible builds (see
3941 When using HTTPS, the server's X.509 certificate is @emph{not} validated
3942 (in other words, the server is not authenticated), contrary to what
3943 HTTPS clients such as Web browsers usually do. This is because Guix
3944 authenticates substitute information itself, as explained above, which
3945 is what we care about (whereas X.509 certificates are about
3946 authenticating bindings between domain names and public keys).
3948 @node Proxy Settings
3949 @subsection Proxy Settings
3953 Substitutes are downloaded over HTTP or HTTPS@. The @env{http_proxy} and
3954 @env{https_proxy} environment variables can be set in the environment of
3955 @command{guix-daemon} and are honored for downloads of substitutes.
3956 Note that the value of those environment variables in the environment
3957 where @command{guix build}, @command{guix package}, and other client
3958 commands are run has @emph{absolutely no effect}.
3960 @node Substitution Failure
3961 @subsection Substitution Failure
3963 Even when a substitute for a derivation is available, sometimes the
3964 substitution attempt will fail. This can happen for a variety of
3965 reasons: the substitute server might be offline, the substitute may
3966 recently have been deleted, the connection might have been interrupted,
3969 When substitutes are enabled and a substitute for a derivation is
3970 available, but the substitution attempt fails, Guix will attempt to
3971 build the derivation locally depending on whether or not
3972 @option{--fallback} was given (@pxref{fallback-option,, common build
3973 option @option{--fallback}}). Specifically, if @option{--fallback} was
3974 omitted, then no local build will be performed, and the derivation is
3975 considered to have failed. However, if @option{--fallback} was given,
3976 then Guix will attempt to build the derivation locally, and the success
3977 or failure of the derivation depends on the success or failure of the
3978 local build. Note that when substitutes are disabled or no substitute
3979 is available for the derivation in question, a local build will
3980 @emph{always} be performed, regardless of whether or not
3981 @option{--fallback} was given.
3983 To get an idea of how many substitutes are available right now, you can
3984 try running the @command{guix weather} command (@pxref{Invoking guix
3985 weather}). This command provides statistics on the substitutes provided
3988 @node On Trusting Binaries
3989 @subsection On Trusting Binaries
3991 @cindex trust, of pre-built binaries
3992 Today, each individual's control over their own computing is at the
3993 mercy of institutions, corporations, and groups with enough power and
3994 determination to subvert the computing infrastructure and exploit its
3995 weaknesses. While using @code{@value{SUBSTITUTE-SERVER}} substitutes can be
3996 convenient, we encourage users to also build on their own, or even run
3997 their own build farm, such that @code{@value{SUBSTITUTE-SERVER}} is less of an
3998 interesting target. One way to help is by publishing the software you
3999 build using @command{guix publish} so that others have one more choice
4000 of server to download substitutes from (@pxref{Invoking guix publish}).
4002 Guix has the foundations to maximize build reproducibility
4003 (@pxref{Features}). In most cases, independent builds of a given
4004 package or derivation should yield bit-identical results. Thus, through
4005 a diverse set of independent package builds, we can strengthen the
4006 integrity of our systems. The @command{guix challenge} command aims to
4007 help users assess substitute servers, and to assist developers in
4008 finding out about non-deterministic package builds (@pxref{Invoking guix
4009 challenge}). Similarly, the @option{--check} option of @command{guix
4010 build} allows users to check whether previously-installed substitutes
4011 are genuine by rebuilding them locally (@pxref{build-check,
4012 @command{guix build --check}}).
4014 In the future, we want Guix to have support to publish and retrieve
4015 binaries to/from other users, in a peer-to-peer fashion. If you would
4016 like to discuss this project, join us on @email{guix-devel@@gnu.org}.
4018 @node Packages with Multiple Outputs
4019 @section Packages with Multiple Outputs
4021 @cindex multiple-output packages
4022 @cindex package outputs
4025 Often, packages defined in Guix have a single @dfn{output}---i.e., the
4026 source package leads to exactly one directory in the store. When running
4027 @command{guix install glibc}, one installs the default output of the
4028 GNU libc package; the default output is called @code{out}, but its name
4029 can be omitted as shown in this command. In this particular case, the
4030 default output of @code{glibc} contains all the C header files, shared
4031 libraries, static libraries, Info documentation, and other supporting
4034 Sometimes it is more appropriate to separate the various types of files
4035 produced from a single source package into separate outputs. For
4036 instance, the GLib C library (used by GTK+ and related packages)
4037 installs more than 20 MiB of reference documentation as HTML pages.
4038 To save space for users who do not need it, the documentation goes to a
4039 separate output, called @code{doc}. To install the main GLib output,
4040 which contains everything but the documentation, one would run:
4046 @cindex documentation
4047 The command to install its documentation is:
4050 guix install glib:doc
4053 Some packages install programs with different ``dependency footprints''.
4054 For instance, the WordNet package installs both command-line tools and
4055 graphical user interfaces (GUIs). The former depend solely on the C
4056 library, whereas the latter depend on Tcl/Tk and the underlying X
4057 libraries. In this case, we leave the command-line tools in the default
4058 output, whereas the GUIs are in a separate output. This allows users
4059 who do not need the GUIs to save space. The @command{guix size} command
4060 can help find out about such situations (@pxref{Invoking guix size}).
4061 @command{guix graph} can also be helpful (@pxref{Invoking guix graph}).
4063 There are several such multiple-output packages in the GNU distribution.
4064 Other conventional output names include @code{lib} for libraries and
4065 possibly header files, @code{bin} for stand-alone programs, and
4066 @code{debug} for debugging information (@pxref{Installing Debugging
4067 Files}). The outputs of a packages are listed in the third column of
4068 the output of @command{guix package --list-available} (@pxref{Invoking
4072 @node Invoking guix gc
4073 @section Invoking @command{guix gc}
4075 @cindex garbage collector
4077 Packages that are installed, but not used, may be @dfn{garbage-collected}.
4078 The @command{guix gc} command allows users to explicitly run the garbage
4079 collector to reclaim space from the @file{/gnu/store} directory. It is
4080 the @emph{only} way to remove files from @file{/gnu/store}---removing
4081 files or directories manually may break it beyond repair!
4084 @cindex garbage collector roots
4085 The garbage collector has a set of known @dfn{roots}: any file under
4086 @file{/gnu/store} reachable from a root is considered @dfn{live} and
4087 cannot be deleted; any other file is considered @dfn{dead} and may be
4088 deleted. The set of garbage collector roots (``GC roots'' for short)
4089 includes default user profiles; by default, the symlinks under
4090 @file{/var/guix/gcroots} represent these GC roots. New GC roots can be
4091 added with @command{guix build --root}, for example (@pxref{Invoking
4092 guix build}). The @command{guix gc --list-roots} command lists them.
4094 Prior to running @code{guix gc --collect-garbage} to make space, it is
4095 often useful to remove old generations from user profiles; that way, old
4096 package builds referenced by those generations can be reclaimed. This
4097 is achieved by running @code{guix package --delete-generations}
4098 (@pxref{Invoking guix package}).
4100 Our recommendation is to run a garbage collection periodically, or when
4101 you are short on disk space. For instance, to guarantee that at least
4102 5@tie{}GB are available on your disk, simply run:
4108 It is perfectly safe to run as a non-interactive periodic job
4109 (@pxref{Scheduled Job Execution}, for how to set up such a job).
4110 Running @command{guix gc} with no arguments will collect as
4111 much garbage as it can, but that is often inconvenient: you may find
4112 yourself having to rebuild or re-download software that is ``dead'' from
4113 the GC viewpoint but that is necessary to build other pieces of
4114 software---e.g., the compiler tool chain.
4116 The @command{guix gc} command has three modes of operation: it can be
4117 used to garbage-collect any dead files (the default), to delete specific
4118 files (the @option{--delete} option), to print garbage-collector
4119 information, or for more advanced queries. The garbage collection
4120 options are as follows:
4123 @item --collect-garbage[=@var{min}]
4124 @itemx -C [@var{min}]
4125 Collect garbage---i.e., unreachable @file{/gnu/store} files and
4126 sub-directories. This is the default operation when no option is
4129 When @var{min} is given, stop once @var{min} bytes have been collected.
4130 @var{min} may be a number of bytes, or it may include a unit as a
4131 suffix, such as @code{MiB} for mebibytes and @code{GB} for gigabytes
4132 (@pxref{Block size, size specifications,, coreutils, GNU Coreutils}).
4134 When @var{min} is omitted, collect all the garbage.
4136 @item --free-space=@var{free}
4137 @itemx -F @var{free}
4138 Collect garbage until @var{free} space is available under
4139 @file{/gnu/store}, if possible; @var{free} denotes storage space, such
4140 as @code{500MiB}, as described above.
4142 When @var{free} or more is already available in @file{/gnu/store}, do
4143 nothing and exit immediately.
4145 @item --delete-generations[=@var{duration}]
4146 @itemx -d [@var{duration}]
4147 Before starting the garbage collection process, delete all the generations
4148 older than @var{duration}, for all the user profiles; when run as root, this
4149 applies to all the profiles @emph{of all the users}.
4151 For example, this command deletes all the generations of all your profiles
4152 that are older than 2 months (except generations that are current), and then
4153 proceeds to free space until at least 10 GiB are available:
4156 guix gc -d 2m -F 10G
4161 Attempt to delete all the store files and directories specified as
4162 arguments. This fails if some of the files are not in the store, or if
4163 they are still live.
4165 @item --list-failures
4166 List store items corresponding to cached build failures.
4168 This prints nothing unless the daemon was started with
4169 @option{--cache-failures} (@pxref{Invoking guix-daemon,
4170 @option{--cache-failures}}).
4173 List the GC roots owned by the user; when run as root, list @emph{all} the GC
4177 List store items in use by currently running processes. These store
4178 items are effectively considered GC roots: they cannot be deleted.
4180 @item --clear-failures
4181 Remove the specified store items from the failed-build cache.
4183 Again, this option only makes sense when the daemon is started with
4184 @option{--cache-failures}. Otherwise, it does nothing.
4187 Show the list of dead files and directories still present in the
4188 store---i.e., files and directories no longer reachable from any root.
4191 Show the list of live store files and directories.
4195 In addition, the references among existing store files can be queried:
4201 @cindex package dependencies
4202 List the references (respectively, the referrers) of store files given
4208 List the requisites of the store files passed as arguments. Requisites
4209 include the store files themselves, their references, and the references
4210 of these, recursively. In other words, the returned list is the
4211 @dfn{transitive closure} of the store files.
4213 @xref{Invoking guix size}, for a tool to profile the size of the closure
4214 of an element. @xref{Invoking guix graph}, for a tool to visualize
4215 the graph of references.
4219 Return the derivation(s) leading to the given store items
4220 (@pxref{Derivations}).
4222 For example, this command:
4225 guix gc --derivers $(guix package -I ^emacs$ | cut -f4)
4229 returns the @file{.drv} file(s) leading to the @code{emacs} package
4230 installed in your profile.
4232 Note that there may be zero matching @file{.drv} files, for instance
4233 because these files have been garbage-collected. There can also be more
4234 than one matching @file{.drv} due to fixed-output derivations.
4237 Lastly, the following options allow you to check the integrity of the
4238 store and to control disk usage.
4242 @item --verify[=@var{options}]
4243 @cindex integrity, of the store
4244 @cindex integrity checking
4245 Verify the integrity of the store.
4247 By default, make sure that all the store items marked as valid in the
4248 database of the daemon actually exist in @file{/gnu/store}.
4250 When provided, @var{options} must be a comma-separated list containing one
4251 or more of @code{contents} and @code{repair}.
4253 When passing @option{--verify=contents}, the daemon computes the
4254 content hash of each store item and compares it against its hash in the
4255 database. Hash mismatches are reported as data corruptions. Because it
4256 traverses @emph{all the files in the store}, this command can take a
4257 long time, especially on systems with a slow disk drive.
4259 @cindex repairing the store
4260 @cindex corruption, recovering from
4261 Using @option{--verify=repair} or @option{--verify=contents,repair}
4262 causes the daemon to try to repair corrupt store items by fetching
4263 substitutes for them (@pxref{Substitutes}). Because repairing is not
4264 atomic, and thus potentially dangerous, it is available only to the
4265 system administrator. A lightweight alternative, when you know exactly
4266 which items in the store are corrupt, is @command{guix build --repair}
4267 (@pxref{Invoking guix build}).
4270 @cindex deduplication
4271 Optimize the store by hard-linking identical files---this is
4272 @dfn{deduplication}.
4274 The daemon performs deduplication after each successful build or archive
4275 import, unless it was started with @option{--disable-deduplication}
4276 (@pxref{Invoking guix-daemon, @option{--disable-deduplication}}). Thus,
4277 this option is primarily useful when the daemon was running with
4278 @option{--disable-deduplication}.
4282 @node Invoking guix pull
4283 @section Invoking @command{guix pull}
4285 @cindex upgrading Guix
4286 @cindex updating Guix
4287 @cindex @command{guix pull}
4289 @cindex security, @command{guix pull}
4290 @cindex authenticity, of code obtained with @command{guix pull}
4291 Packages are installed or upgraded to the latest version available in
4292 the distribution currently available on your local machine. To update
4293 that distribution, along with the Guix tools, you must run @command{guix
4294 pull}: the command downloads the latest Guix source code and package
4295 descriptions, and deploys it. Source code is downloaded from a
4296 @uref{https://git-scm.com, Git} repository, by default the official
4297 GNU@tie{}Guix repository, though this can be customized. @command{guix
4298 pull} ensures that the code it downloads is @emph{authentic} by
4299 verifying that commits are signed by Guix developers.
4301 Specifically, @command{guix pull} downloads code from the @dfn{channels}
4302 (@pxref{Channels}) specified by one of the followings, in this order:
4306 the @option{--channels} option;
4308 the user's @file{~/.config/guix/channels.scm} file;
4310 the system-wide @file{/etc/guix/channels.scm} file;
4312 the built-in default channels specified in the @code{%default-channels}
4316 On completion, @command{guix package} will use packages and package
4317 versions from this just-retrieved copy of Guix. Not only that, but all
4318 the Guix commands and Scheme modules will also be taken from that latest
4319 version. New @command{guix} sub-commands added by the update also
4322 Any user can update their Guix copy using @command{guix pull}, and the
4323 effect is limited to the user who ran @command{guix pull}. For
4324 instance, when user @code{root} runs @command{guix pull}, this has no
4325 effect on the version of Guix that user @code{alice} sees, and vice
4328 The result of running @command{guix pull} is a @dfn{profile} available
4329 under @file{~/.config/guix/current} containing the latest Guix. Thus,
4330 make sure to add it to the beginning of your search path so that you use
4331 the latest version, and similarly for the Info manual
4332 (@pxref{Documentation}):
4335 export PATH="$HOME/.config/guix/current/bin:$PATH"
4336 export INFOPATH="$HOME/.config/guix/current/share/info:$INFOPATH"
4339 The @option{--list-generations} or @option{-l} option lists past generations
4340 produced by @command{guix pull}, along with details about their provenance:
4344 Generation 1 Jun 10 2018 00:18:18
4346 repository URL: https://git.savannah.gnu.org/git/guix.git
4347 branch: origin/master
4348 commit: 65956ad3526ba09e1f7a40722c96c6ef7c0936fe
4350 Generation 2 Jun 11 2018 11:02:49
4352 repository URL: https://git.savannah.gnu.org/git/guix.git
4353 branch: origin/master
4354 commit: e0cc7f669bec22c37481dd03a7941c7d11a64f1d
4355 2 new packages: keepalived, libnfnetlink
4356 6 packages upgraded: emacs-nix-mode@@2.0.4,
4357 guile2.0-guix@@0.14.0-12.77a1aac, guix@@0.14.0-12.77a1aac,
4358 heimdal@@7.5.0, milkytracker@@1.02.00, nix@@2.0.4
4360 Generation 3 Jun 13 2018 23:31:07 (current)
4362 repository URL: https://git.savannah.gnu.org/git/guix.git
4363 branch: origin/master
4364 commit: 844cc1c8f394f03b404c5bb3aee086922373490c
4365 28 new packages: emacs-helm-ls-git, emacs-helm-mu, @dots{}
4366 69 packages upgraded: borg@@1.1.6, cheese@@3.28.0, @dots{}
4369 @xref{Invoking guix describe, @command{guix describe}}, for other ways to
4370 describe the current status of Guix.
4372 This @code{~/.config/guix/current} profile works exactly like the profiles
4373 created by @command{guix package} (@pxref{Invoking guix package}). That
4374 is, you can list generations, roll back to the previous
4375 generation---i.e., the previous Guix---and so on:
4378 $ guix pull --roll-back
4379 switched from generation 3 to 2
4380 $ guix pull --delete-generations=1
4381 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4384 You can also use @command{guix package} (@pxref{Invoking guix package})
4385 to manage the profile by naming it explicitly:
4387 $ guix package -p ~/.config/guix/current --roll-back
4388 switched from generation 3 to 2
4389 $ guix package -p ~/.config/guix/current --delete-generations=1
4390 deleting /var/guix/profiles/per-user/charlie/current-guix-1-link
4393 The @command{guix pull} command is usually invoked with no arguments,
4394 but it supports the following options:
4397 @item --url=@var{url}
4398 @itemx --commit=@var{commit}
4399 @itemx --branch=@var{branch}
4400 Download code for the @code{guix} channel from the specified @var{url}, at the
4401 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4402 string), or @var{branch}.
4404 @cindex @file{channels.scm}, configuration file
4405 @cindex configuration file for channels
4406 These options are provided for convenience, but you can also specify your
4407 configuration in the @file{~/.config/guix/channels.scm} file or using the
4408 @option{--channels} option (see below).
4410 @item --channels=@var{file}
4411 @itemx -C @var{file}
4412 Read the list of channels from @var{file} instead of
4413 @file{~/.config/guix/channels.scm} or @file{/etc/guix/channels.scm}.
4414 @var{file} must contain Scheme code that
4415 evaluates to a list of channel objects. @xref{Channels}, for more
4418 @cindex channel news
4421 Display the list of packages added or upgraded since the previous
4422 generation, as well as, occasionally, news written by channel authors
4423 for their users (@pxref{Channels, Writing Channel News}).
4425 The package information is the same as displayed upon @command{guix
4426 pull} completion, but without ellipses; it is also similar to the output
4427 of @command{guix pull -l} for the last generation (see below).
4429 @item --list-generations[=@var{pattern}]
4430 @itemx -l [@var{pattern}]
4431 List all the generations of @file{~/.config/guix/current} or, if @var{pattern}
4432 is provided, the subset of generations that match @var{pattern}.
4433 The syntax of @var{pattern} is the same as with @code{guix package
4434 --list-generations} (@pxref{Invoking guix package}).
4437 @cindex rolling back
4438 @cindex undoing transactions
4439 @cindex transactions, undoing
4440 Roll back to the previous @dfn{generation} of @file{~/.config/guix/current}---i.e.,
4441 undo the last transaction.
4443 @item --switch-generation=@var{pattern}
4444 @itemx -S @var{pattern}
4446 Switch to a particular generation defined by @var{pattern}.
4448 @var{pattern} may be either a generation number or a number prefixed
4449 with ``+'' or ``-''. The latter means: move forward/backward by a
4450 specified number of generations. For example, if you want to return to
4451 the latest generation after @option{--roll-back}, use
4452 @option{--switch-generation=+1}.
4454 @item --delete-generations[=@var{pattern}]
4455 @itemx -d [@var{pattern}]
4456 When @var{pattern} is omitted, delete all generations except the current
4459 This command accepts the same patterns as @option{--list-generations}.
4460 When @var{pattern} is specified, delete the matching generations. When
4461 @var{pattern} specifies a duration, generations @emph{older} than the
4462 specified duration match. For instance, @option{--delete-generations=1m}
4463 deletes generations that are more than one month old.
4465 If the current generation matches, it is @emph{not} deleted.
4467 Note that deleting generations prevents rolling back to them.
4468 Consequently, this command must be used with care.
4470 @xref{Invoking guix describe}, for a way to display information about the
4471 current generation only.
4473 @item --profile=@var{profile}
4474 @itemx -p @var{profile}
4475 Use @var{profile} instead of @file{~/.config/guix/current}.
4479 Show which channel commit(s) would be used and what would be built or
4480 substituted but do not actually do it.
4482 @item --allow-downgrades
4483 Allow pulling older or unrelated revisions of channels than those
4486 @cindex downgrade attacks, protection against
4487 By default, @command{guix pull} protects against so-called ``downgrade
4488 attacks'' whereby the Git repository of a channel would be reset to an
4489 earlier or unrelated revision of itself, potentially leading you to
4490 install older, known-vulnerable versions of software packages.
4493 Make sure you understand its security implications before using
4494 @option{--allow-downgrades}.
4497 @item --disable-authentication
4498 Allow pulling channel code without authenticating it.
4500 @cindex authentication, of channel code
4501 By default, @command{guix pull} authenticates code downloaded from
4502 channels by verifying that its commits are signed by authorized
4503 developers, and raises an error if this is not the case. This option
4504 instructs it to not perform any such verification.
4507 Make sure you understand its security implications before using
4508 @option{--disable-authentication}.
4511 @item --system=@var{system}
4512 @itemx -s @var{system}
4513 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
4514 the system type of the build host.
4517 Use the bootstrap Guile to build the latest Guix. This option is only
4518 useful to Guix developers.
4521 The @dfn{channel} mechanism allows you to instruct @command{guix pull} which
4522 repository and branch to pull from, as well as @emph{additional} repositories
4523 containing package modules that should be deployed. @xref{Channels}, for more
4526 In addition, @command{guix pull} supports all the common build options
4527 (@pxref{Common Build Options}).
4529 @node Invoking guix time-machine
4530 @section Invoking @command{guix time-machine}
4532 @cindex @command{guix time-machine}
4533 @cindex pinning, channels
4534 @cindex replicating Guix
4535 @cindex reproducibility, of Guix
4537 The @command{guix time-machine} command provides access to other
4538 revisions of Guix, for example to install older versions of packages,
4539 or to reproduce a computation in an identical environment. The revision
4540 of Guix to be used is defined by a commit or by a channel
4541 description file created by @command{guix describe}
4542 (@pxref{Invoking guix describe}).
4544 The general syntax is:
4547 guix time-machine @var{options}@dots{} -- @var{command} @var {arg}@dots{}
4550 where @var{command} and @var{arg}@dots{} are passed unmodified to the
4551 @command{guix} command of the specified revision. The @var{options} that define
4552 this revision are the same as for @command{guix pull} (@pxref{Invoking guix pull}):
4555 @item --url=@var{url}
4556 @itemx --commit=@var{commit}
4557 @itemx --branch=@var{branch}
4558 Use the @code{guix} channel from the specified @var{url}, at the
4559 given @var{commit} (a valid Git commit ID represented as a hexadecimal
4560 string), or @var{branch}.
4562 @item --channels=@var{file}
4563 @itemx -C @var{file}
4564 Read the list of channels from @var{file}. @var{file} must contain
4565 Scheme code that evaluates to a list of channel objects.
4566 @xref{Channels} for more information.
4569 As for @command{guix pull}, the absence of any options means that the
4570 latest commit on the master branch will be used. The command
4573 guix time-machine -- build hello
4576 will thus build the package @code{hello} as defined in the master branch,
4577 which is in general a newer revision of Guix than you have installed.
4578 Time travel works in both directions!
4580 Note that @command{guix time-machine} can trigger builds of channels and
4581 their dependencies, and these are controlled by the standard build
4582 options (@pxref{Common Build Options}).
4587 @c TODO: Remove this once we're more confident about API stability.
4589 The functionality described here is a ``technology preview'' as of version
4590 @value{VERSION}. As such, the interface is subject to change.
4594 @cindex composition of Guix revisions
4595 Sometimes you might need to mix packages from the revision of Guix you're
4596 currently running with packages available in a different revision of Guix.
4597 Guix @dfn{inferiors} allow you to achieve that by composing different Guix
4598 revisions in arbitrary ways.
4600 @cindex inferior packages
4601 Technically, an ``inferior'' is essentially a separate Guix process connected
4602 to your main Guix process through a REPL (@pxref{Invoking guix repl}). The
4603 @code{(guix inferior)} module allows you to create inferiors and to
4604 communicate with them. It also provides a high-level interface to browse and
4605 manipulate the packages that an inferior provides---@dfn{inferior packages}.
4607 When combined with channels (@pxref{Channels}), inferiors provide a simple way
4608 to interact with a separate revision of Guix. For example, let's assume you
4609 want to install in your profile the current @code{guile} package, along with
4610 the @code{guile-json} as it existed in an older revision of Guix---perhaps
4611 because the newer @code{guile-json} has an incompatible API and you want to
4612 run your code against the old API@. To do that, you could write a manifest for
4613 use by @code{guix package --manifest} (@pxref{Invoking guix package}); in that
4614 manifest, you would create an inferior for that old Guix revision you care
4615 about, and you would look up the @code{guile-json} package in the inferior:
4618 (use-modules (guix inferior) (guix channels)
4619 (srfi srfi-1)) ;for 'first'
4622 ;; This is the old revision from which we want to
4623 ;; extract guile-json.
4626 (url "https://git.savannah.gnu.org/git/guix.git")
4628 "65956ad3526ba09e1f7a40722c96c6ef7c0936fe"))))
4631 ;; An inferior representing the above revision.
4632 (inferior-for-channels channels))
4634 ;; Now create a manifest with the current "guile" package
4635 ;; and the old "guile-json" package.
4637 (list (first (lookup-inferior-packages inferior "guile-json"))
4638 (specification->package "guile")))
4641 On its first run, @command{guix package --manifest} might have to build the
4642 channel you specified before it can create the inferior; subsequent runs will
4643 be much faster because the Guix revision will be cached.
4645 The @code{(guix inferior)} module provides the following procedures to open an
4648 @deffn {Scheme Procedure} inferior-for-channels @var{channels} @
4649 [#:cache-directory] [#:ttl]
4650 Return an inferior for @var{channels}, a list of channels. Use the cache at
4651 @var{cache-directory}, where entries can be reclaimed after @var{ttl} seconds.
4652 This procedure opens a new connection to the build daemon.
4654 As a side effect, this procedure may build or substitute binaries for
4655 @var{channels}, which can take time.
4658 @deffn {Scheme Procedure} open-inferior @var{directory} @
4659 [#:command "bin/guix"]
4660 Open the inferior Guix in @var{directory}, running
4661 @code{@var{directory}/@var{command} repl} or equivalent. Return @code{#f} if
4662 the inferior could not be launched.
4665 @cindex inferior packages
4666 The procedures listed below allow you to obtain and manipulate inferior
4669 @deffn {Scheme Procedure} inferior-packages @var{inferior}
4670 Return the list of packages known to @var{inferior}.
4673 @deffn {Scheme Procedure} lookup-inferior-packages @var{inferior} @var{name} @
4675 Return the sorted list of inferior packages matching @var{name} in
4676 @var{inferior}, with highest version numbers first. If @var{version} is true,
4677 return only packages with a version number prefixed by @var{version}.
4680 @deffn {Scheme Procedure} inferior-package? @var{obj}
4681 Return true if @var{obj} is an inferior package.
4684 @deffn {Scheme Procedure} inferior-package-name @var{package}
4685 @deffnx {Scheme Procedure} inferior-package-version @var{package}
4686 @deffnx {Scheme Procedure} inferior-package-synopsis @var{package}
4687 @deffnx {Scheme Procedure} inferior-package-description @var{package}
4688 @deffnx {Scheme Procedure} inferior-package-home-page @var{package}
4689 @deffnx {Scheme Procedure} inferior-package-location @var{package}
4690 @deffnx {Scheme Procedure} inferior-package-inputs @var{package}
4691 @deffnx {Scheme Procedure} inferior-package-native-inputs @var{package}
4692 @deffnx {Scheme Procedure} inferior-package-propagated-inputs @var{package}
4693 @deffnx {Scheme Procedure} inferior-package-transitive-propagated-inputs @var{package}
4694 @deffnx {Scheme Procedure} inferior-package-native-search-paths @var{package}
4695 @deffnx {Scheme Procedure} inferior-package-transitive-native-search-paths @var{package}
4696 @deffnx {Scheme Procedure} inferior-package-search-paths @var{package}
4697 These procedures are the counterpart of package record accessors
4698 (@pxref{package Reference}). Most of them work by querying the inferior
4699 @var{package} comes from, so the inferior must still be live when you call
4703 Inferior packages can be used transparently like any other package or
4704 file-like object in G-expressions (@pxref{G-Expressions}). They are also
4705 transparently handled by the @code{packages->manifest} procedure, which is
4706 commonly used in manifests (@pxref{Invoking guix package, the
4707 @option{--manifest} option of @command{guix package}}). Thus you can insert
4708 an inferior package pretty much anywhere you would insert a regular package:
4709 in manifests, in the @code{packages} field of your @code{operating-system}
4710 declaration, and so on.
4712 @node Invoking guix describe
4713 @section Invoking @command{guix describe}
4715 @cindex reproducibility
4716 @cindex replicating Guix
4717 Often you may want to answer questions like: ``Which revision of Guix am I
4718 using?'' or ``Which channels am I using?'' This is useful information in many
4719 situations: if you want to @emph{replicate} an environment on a different
4720 machine or user account, if you want to report a bug or to determine what
4721 change in the channels you are using caused it, or if you want to record your
4722 system state for reproducibility purposes. The @command{guix describe}
4723 command answers these questions.
4725 When run from a @command{guix pull}ed @command{guix}, @command{guix describe}
4726 displays the channel(s) that it was built from, including their repository URL
4727 and commit IDs (@pxref{Channels}):
4731 Generation 10 Sep 03 2018 17:32:44 (current)
4733 repository URL: https://git.savannah.gnu.org/git/guix.git
4735 commit: e0fa68c7718fffd33d81af415279d6ddb518f727
4738 If you're familiar with the Git version control system, this is similar in
4739 spirit to @command{git describe}; the output is also similar to that of
4740 @command{guix pull --list-generations}, but limited to the current generation
4741 (@pxref{Invoking guix pull, the @option{--list-generations} option}). Because
4742 the Git commit ID shown above unambiguously refers to a snapshot of Guix, this
4743 information is all it takes to describe the revision of Guix you're using, and
4744 also to replicate it.
4746 To make it easier to replicate Guix, @command{guix describe} can also be asked
4747 to return a list of channels instead of the human-readable description above:
4750 $ guix describe -f channels
4753 (url "https://git.savannah.gnu.org/git/guix.git")
4755 "e0fa68c7718fffd33d81af415279d6ddb518f727")
4757 (make-channel-introduction
4758 "9edb3f66fd807b096b48283debdcddccfea34bad"
4759 (openpgp-fingerprint
4760 "BBB0 2DDF 2CEA F6A8 0D1D E643 A2A0 6DF2 A33A 54FA")))))
4764 You can save this to a file and feed it to @command{guix pull -C} on some
4765 other machine or at a later point in time, which will instantiate @emph{this
4766 exact Guix revision} (@pxref{Invoking guix pull, the @option{-C} option}).
4767 From there on, since you're able to deploy the same revision of Guix, you can
4768 just as well @emph{replicate a complete software environment}. We humbly
4769 think that this is @emph{awesome}, and we hope you'll like it too!
4771 The details of the options supported by @command{guix describe} are as
4775 @item --format=@var{format}
4776 @itemx -f @var{format}
4777 Produce output in the specified @var{format}, one of:
4781 produce human-readable output;
4783 produce a list of channel specifications that can be passed to @command{guix
4784 pull -C} or installed as @file{~/.config/guix/channels.scm} (@pxref{Invoking
4786 @item channels-sans-intro
4787 like @code{channels}, but omit the @code{introduction} field; use it to
4788 produce a channel specification suitable for Guix version 1.1.0 or
4789 earlier---the @code{introduction} field has to do with channel
4790 authentication (@pxref{Channels, Channel Authentication}) and is not
4791 supported by these older versions;
4794 produce a list of channel specifications in JSON format;
4796 produce a list of channel specifications in Recutils format.
4799 @item --list-formats
4800 Display available formats for @option{--format} option.
4802 @item --profile=@var{profile}
4803 @itemx -p @var{profile}
4804 Display information about @var{profile}.
4807 @node Invoking guix archive
4808 @section Invoking @command{guix archive}
4810 @cindex @command{guix archive}
4812 The @command{guix archive} command allows users to @dfn{export} files
4813 from the store into a single archive, and to later @dfn{import} them on
4814 a machine that runs Guix.
4815 In particular, it allows store files to be transferred from one machine
4816 to the store on another machine.
4819 If you're looking for a way to produce archives in a format suitable for
4820 tools other than Guix, @pxref{Invoking guix pack}.
4823 @cindex exporting store items
4824 To export store files as an archive to standard output, run:
4827 guix archive --export @var{options} @var{specifications}...
4830 @var{specifications} may be either store file names or package
4831 specifications, as for @command{guix package} (@pxref{Invoking guix
4832 package}). For instance, the following command creates an archive
4833 containing the @code{gui} output of the @code{git} package and the main
4834 output of @code{emacs}:
4837 guix archive --export git:gui /gnu/store/...-emacs-24.3 > great.nar
4840 If the specified packages are not built yet, @command{guix archive}
4841 automatically builds them. The build process may be controlled with the
4842 common build options (@pxref{Common Build Options}).
4844 To transfer the @code{emacs} package to a machine connected over SSH,
4848 guix archive --export -r emacs | ssh the-machine guix archive --import
4852 Similarly, a complete user profile may be transferred from one machine
4853 to another like this:
4856 guix archive --export -r $(readlink -f ~/.guix-profile) | \
4857 ssh the-machine guix archive --import
4861 However, note that, in both examples, all of @code{emacs} and the
4862 profile as well as all of their dependencies are transferred (due to
4863 @option{-r}), regardless of what is already available in the store on
4864 the target machine. The @option{--missing} option can help figure out
4865 which items are missing from the target store. The @command{guix copy}
4866 command simplifies and optimizes this whole process, so this is probably
4867 what you should use in this case (@pxref{Invoking guix copy}).
4869 @cindex nar, archive format
4870 @cindex normalized archive (nar)
4871 @cindex nar bundle, archive format
4872 Each store item is written in the @dfn{normalized archive} or @dfn{nar}
4873 format (described below), and the output of @command{guix archive
4874 --export} (and input of @command{guix archive --import}) is a @dfn{nar
4878 comparable in spirit to `tar', but with differences
4879 that make it more appropriate for our purposes. First, rather than
4880 recording all Unix metadata for each file, the nar format only mentions
4881 the file type (regular, directory, or symbolic link); Unix permissions
4882 and owner/group are dismissed. Second, the order in which directory
4883 entries are stored always follows the order of file names according to
4884 the C locale collation order. This makes archive production fully
4887 That nar bundle format is essentially the concatenation of zero or more
4888 nars along with metadata for each store item it contains: its file name,
4889 references, corresponding derivation, and a digital signature.
4891 When exporting, the daemon digitally signs the contents of the archive,
4892 and that digital signature is appended. When importing, the daemon
4893 verifies the signature and rejects the import in case of an invalid
4894 signature or if the signing key is not authorized.
4895 @c FIXME: Add xref to daemon doc about signatures.
4897 The main options are:
4901 Export the specified store files or packages (see below). Write the
4902 resulting archive to the standard output.
4904 Dependencies are @emph{not} included in the output, unless
4905 @option{--recursive} is passed.
4909 When combined with @option{--export}, this instructs @command{guix archive}
4910 to include dependencies of the given items in the archive. Thus, the
4911 resulting archive is self-contained: it contains the closure of the
4912 exported store items.
4915 Read an archive from the standard input, and import the files listed
4916 therein into the store. Abort if the archive has an invalid digital
4917 signature, or if it is signed by a public key not among the authorized
4918 keys (see @option{--authorize} below).
4921 Read a list of store file names from the standard input, one per line,
4922 and write on the standard output the subset of these files missing from
4925 @item --generate-key[=@var{parameters}]
4926 @cindex signing, archives
4927 Generate a new key pair for the daemon. This is a prerequisite before
4928 archives can be exported with @option{--export}. This
4929 operation is usually instantaneous but it can take time if the system's
4930 entropy pool needs to be refilled. On Guix System,
4931 @code{guix-service-type} takes care of generating this key pair the
4934 The generated key pair is typically stored under @file{/etc/guix}, in
4935 @file{signing-key.pub} (public key) and @file{signing-key.sec} (private
4936 key, which must be kept secret). When @var{parameters} is omitted,
4937 an ECDSA key using the Ed25519 curve is generated, or, for Libgcrypt
4938 versions before 1.6.0, it is a 4096-bit RSA key.
4939 Alternatively, @var{parameters} can specify
4940 @code{genkey} parameters suitable for Libgcrypt (@pxref{General
4941 public-key related Functions, @code{gcry_pk_genkey},, gcrypt, The
4942 Libgcrypt Reference Manual}).
4945 @cindex authorizing, archives
4946 Authorize imports signed by the public key passed on standard input.
4947 The public key must be in ``s-expression advanced format''---i.e., the
4948 same format as the @file{signing-key.pub} file.
4950 The list of authorized keys is kept in the human-editable file
4951 @file{/etc/guix/acl}. The file contains
4952 @url{https://people.csail.mit.edu/rivest/Sexp.txt, ``advanced-format
4953 s-expressions''} and is structured as an access-control list in the
4954 @url{https://theworld.com/~cme/spki.txt, Simple Public-Key Infrastructure
4957 @item --extract=@var{directory}
4958 @itemx -x @var{directory}
4959 Read a single-item archive as served by substitute servers
4960 (@pxref{Substitutes}) and extract it to @var{directory}. This is a
4961 low-level operation needed in only very narrow use cases; see below.
4963 For example, the following command extracts the substitute for Emacs
4964 served by @code{@value{SUBSTITUTE-SERVER}} to @file{/tmp/emacs}:
4968 https://@value{SUBSTITUTE-SERVER}/nar/gzip/@dots{}-emacs-24.5 \
4969 | gunzip | guix archive -x /tmp/emacs
4972 Single-item archives are different from multiple-item archives produced
4973 by @command{guix archive --export}; they contain a single store item,
4974 and they do @emph{not} embed a signature. Thus this operation does
4975 @emph{no} signature verification and its output should be considered
4978 The primary purpose of this operation is to facilitate inspection of
4979 archive contents coming from possibly untrusted substitute servers
4980 (@pxref{Invoking guix challenge}).
4984 Read a single-item archive as served by substitute servers
4985 (@pxref{Substitutes}) and print the list of files it contains, as in
4990 https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-emacs-26.3 \
4991 | lzip -d | guix archive -t
4996 @c *********************************************************************
5001 @cindex @file{channels.scm}, configuration file
5002 @cindex configuration file for channels
5003 @cindex @command{guix pull}, configuration file
5004 @cindex configuration of @command{guix pull}
5005 Guix and its package collection are updated by running @command{guix pull}
5006 (@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
5007 deploys Guix itself from the official GNU@tie{}Guix repository. This can be
5008 customized by defining @dfn{channels} in the
5009 @file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
5010 of a Git repository to be deployed, and @command{guix pull} can be instructed
5011 to pull from one or more channels. In other words, channels can be used
5012 to @emph{customize} and to @emph{extend} Guix, as we will see below.
5013 Guix is able to take into account security concerns and deal with authenticated
5017 * Specifying Additional Channels:: Extending the package collection.
5018 * Using a Custom Guix Channel:: Using a customized Guix.
5019 * Replicating Guix:: Running the @emph{exact same} Guix.
5020 * Channel Authentication:: How Guix verifies what it fetches.
5021 * Channels with Substitutes:: Using channels with available substitutes.
5022 * Creating a Channel:: How to write your custom channel.
5023 * Package Modules in a Sub-directory:: Specifying the channel's package modules location.
5024 * Declaring Channel Dependencies:: How to depend on other channels.
5025 * Specifying Channel Authorizations:: Defining channel authors authorizations.
5026 * Primary URL:: Distinguishing mirror to original.
5027 * Writing Channel News:: Communicating information to channel's users.
5030 @node Specifying Additional Channels
5031 @section Specifying Additional Channels
5033 @cindex extending the package collection (channels)
5034 @cindex variant packages (channels)
5035 You can specify @emph{additional channels} to pull from. To use a channel, write
5036 @code{~/.config/guix/channels.scm} to instruct @command{guix pull} to pull from it
5037 @emph{in addition} to the default Guix channel(s):
5039 @vindex %default-channels
5041 ;; Add variant packages to those Guix provides.
5043 (name 'variant-packages)
5044 (url "https://example.org/variant-packages.git"))
5049 Note that the snippet above is (as always!)@: Scheme code; we use @code{cons} to
5050 add a channel the list of channels that the variable @code{%default-channels}
5051 is bound to (@pxref{Pairs, @code{cons} and lists,, guile, GNU Guile Reference
5052 Manual}). With this file in place, @command{guix pull} builds not only Guix
5053 but also the package modules from your own repository. The result in
5054 @file{~/.config/guix/current} is the union of Guix with your own package
5058 $ guix pull --list-generations
5060 Generation 19 Aug 27 2018 16:20:48
5062 repository URL: https://git.savannah.gnu.org/git/guix.git
5064 commit: d894ab8e9bfabcefa6c49d9ba2e834dd5a73a300
5065 variant-packages dd3df5e
5066 repository URL: https://example.org/variant-packages.git
5068 commit: dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb
5069 11 new packages: variant-gimp, variant-emacs-with-cool-features, @dots{}
5070 4 packages upgraded: emacs-racket-mode@@0.0.2-2.1b78827, @dots{}
5074 The output of @command{guix pull} above shows that Generation@tie{}19 includes
5075 both Guix and packages from the @code{variant-personal-packages} channel. Among
5076 the new and upgraded packages that are listed, some like @code{variant-gimp} and
5077 @code{variant-emacs-with-cool-features} might come from
5078 @code{variant-packages}, while others come from the Guix default channel.
5080 @node Using a Custom Guix Channel
5081 @section Using a Custom Guix Channel
5083 The channel called @code{guix} specifies where Guix itself---its command-line
5084 tools as well as its package collection---should be downloaded. For instance,
5085 suppose you want to update from another copy of the Guix repository at
5086 @code{example.org}, and specifically the @code{super-hacks} branch, you can
5087 write in @code{~/.config/guix/channels.scm} this specification:
5090 ;; Tell 'guix pull' to use another repo.
5093 (url "https://example.org/another-guix.git")
5094 (branch "super-hacks")))
5098 From there on, @command{guix pull} will fetch code from the @code{super-hacks}
5099 branch of the repository at @code{example.org}. The authentication concern is
5100 addressed below ((@pxref{Channel Authentication}).
5102 @node Replicating Guix
5103 @section Replicating Guix
5105 @cindex pinning, channels
5106 @cindex replicating Guix
5107 @cindex reproducibility, of Guix
5108 The @command{guix pull --list-generations} output above shows precisely which
5109 commits were used to build this instance of Guix. We can thus replicate it,
5110 say, on another machine, by providing a channel specification in
5111 @file{~/.config/guix/channels.scm} that is ``pinned'' to these commits:
5114 ;; Deploy specific commits of my channels of interest.
5117 (url "https://git.savannah.gnu.org/git/guix.git")
5118 (commit "6298c3ffd9654d3231a6f25390b056483e8f407c"))
5120 (name 'variant-packages)
5121 (url "https://example.org/variant-packages.git")
5122 (commit "dd3df5e2c8818760a8fc0bd699e55d3b69fef2bb")))
5125 The @command{guix describe --format=channels} command can even generate this
5126 list of channels directly (@pxref{Invoking guix describe}). The resulting
5127 file can be used with the -C options of @command{guix pull}
5128 (@pxref{Invoking guix pull}) or @command{guix time-machine}
5129 (@pxref{Invoking guix time-machine}).
5131 At this point the two machines run the @emph{exact same Guix}, with access to
5132 the @emph{exact same packages}. The output of @command{guix build gimp} on
5133 one machine will be exactly the same, bit for bit, as the output of the same
5134 command on the other machine. It also means both machines have access to all
5135 the source code of Guix and, transitively, to all the source code of every
5138 This gives you super powers, allowing you to track the provenance of binary
5139 artifacts with very fine grain, and to reproduce software environments at
5140 will---some sort of ``meta reproducibility'' capabilities, if you will.
5141 @xref{Inferiors}, for another way to take advantage of these super powers.
5143 @node Channel Authentication
5144 @section Channel Authentication
5146 @anchor{channel-authentication}
5147 @cindex authentication, of channel code
5148 The @command{guix pull} and @command{guix time-machine} commands
5149 @dfn{authenticate} the code retrieved from channels: they make sure each
5150 commit that is fetched is signed by an authorized developer. The goal
5151 is to protect from unauthorized modifications to the channel that would
5152 lead users to run malicious code.
5154 As a user, you must provide a @dfn{channel introduction} in your
5155 channels file so that Guix knows how to authenticate its first commit.
5156 A channel specification, including its introduction, looks something
5161 (name 'some-channel)
5162 (url "https://example.org/some-channel.git")
5164 (make-channel-introduction
5165 "6f0d8cc0d88abb59c324b2990bfee2876016bb86"
5166 (openpgp-fingerprint
5167 "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5170 The specification above shows the name and URL of the channel. The call
5171 to @code{make-channel-introduction} above specifies that authentication
5172 of this channel starts at commit @code{6f0d8cc@dots{}}, which is signed
5173 by the OpenPGP key with fingerprint @code{CABB A931@dots{}}.
5175 For the main channel, called @code{guix}, you automatically get that
5176 information from your Guix installation. For other channels, include
5177 the channel introduction provided by the channel authors in your
5178 @file{channels.scm} file. Make sure you retrieve the channel
5179 introduction from a trusted source since that is the root of your trust.
5181 If you're curious about the authentication mechanics, read on!
5183 @node Channels with Substitutes
5184 @section Channels with Substitutes
5186 When running @command{guix pull}, Guix will first compile the
5187 definitions of every available package. This is an expensive operation
5188 for which substitutes (@pxref{Substitutes}) may be available. The
5189 following snippet in @file{channels.scm} will ensure that @command{guix
5190 pull} uses the latest commit with available substitutes for the package
5191 definitions: this is done by querying the continuous integration
5192 server at @url{https://ci.guix.gnu.org}.
5195 (use-modules (guix ci))
5197 (list (channel-with-substitutes-available
5198 %default-guix-channel
5199 "https://ci.guix.gnu.org"))
5202 Note that this does not mean that all the packages that you will
5203 install after running @command{guix pull} will have available
5204 substitutes. It only ensures that @command{guix pull} will not try to
5205 compile package definitions. This is particularly useful when using
5206 machines with limited resources.
5208 @node Creating a Channel
5209 @section Creating a Channel
5211 @cindex personal packages (channels)
5212 @cindex channels, for personal packages
5213 Let's say you have a bunch of custom package variants or personal packages
5214 that you think would make little sense to contribute to the Guix project, but
5215 would like to have these packages transparently available to you at the
5216 command line. You would first write modules containing those package
5217 definitions (@pxref{Package Modules}), maintain them in a Git repository, and
5218 then you and anyone else can use it as an additional channel to get packages
5221 @c What follows stems from discussions at
5222 @c <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22629#134> as well as
5223 @c earlier discussions on guix-devel@gnu.org.
5225 Before you, dear user, shout---``woow this is @emph{soooo coool}!''---and
5226 publish your personal channel to the world, we would like to share a few words
5231 Before publishing a channel, please consider contributing your package
5232 definitions to Guix proper (@pxref{Contributing}). Guix as a project is open
5233 to free software of all sorts, and packages in Guix proper are readily
5234 available to all Guix users and benefit from the project's quality assurance
5238 When you maintain package definitions outside Guix, we, Guix developers,
5239 consider that @emph{the compatibility burden is on you}. Remember that
5240 package modules and package definitions are just Scheme code that uses various
5241 programming interfaces (APIs). We want to remain free to change these APIs to
5242 keep improving Guix, possibly in ways that break your channel. We never
5243 change APIs gratuitously, but we will @emph{not} commit to freezing APIs
5247 Corollary: if you're using an external channel and that channel breaks, please
5248 @emph{report the issue to the channel authors}, not to the Guix project.
5251 You've been warned! Having said this, we believe external channels are a
5252 practical way to exert your freedom to augment Guix' package collection and to
5253 share your improvements, which are basic tenets of
5254 @uref{https://www.gnu.org/philosophy/free-sw.html, free software}. Please
5255 email us at @email{guix-devel@@gnu.org} if you'd like to discuss this.
5258 To create a channel, create a Git repository containing your own package
5259 modules and make it available. The repository can contain anything, but a
5260 useful channel will contain Guile modules that export packages. Once you
5261 start using a channel, Guix will behave as if the root directory of that
5262 channel's Git repository has been added to the Guile load path (@pxref{Load
5263 Paths,,, guile, GNU Guile Reference Manual}). For example, if your channel
5264 contains a file at @file{my-packages/my-tools.scm} that defines a Guile
5265 module, then the module will be available under the name @code{(my-packages
5266 my-tools)}, and you will be able to use it like any other module
5267 (@pxref{Modules,,, guile, GNU Guile Reference Manual}).
5269 As a channel author, consider bundling authentication material with your
5270 channel so that users can authenticate it. @xref{Channel
5271 Authentication}, and @ref{Specifying Channel Authorizations}, for info
5275 @node Package Modules in a Sub-directory
5276 @section Package Modules in a Sub-directory
5278 @cindex subdirectory, channels
5279 As a channel author, you may want to keep your channel modules in a
5280 sub-directory. If your modules are in the sub-directory @file{guix}, you must
5281 add a meta-data file @file{.guix-channel} that contains:
5289 @node Declaring Channel Dependencies
5290 @section Declaring Channel Dependencies
5292 @cindex dependencies, channels
5293 @cindex meta-data, channels
5294 Channel authors may decide to augment a package collection provided by other
5295 channels. They can declare their channel to be dependent on other channels in
5296 a meta-data file @file{.guix-channel}, which is to be placed in the root of
5297 the channel repository.
5299 The meta-data file should contain a simple S-expression like this:
5306 (name some-collection)
5307 (url "https://example.org/first-collection.git")
5309 ;; The 'introduction' bit below is optional: you would
5310 ;; provide it for dependencies that can be authenticated.
5312 (channel-introduction
5314 (commit "a8883b58dc82e167c96506cf05095f37c2c2c6cd")
5315 (signer "CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"))))
5317 (name some-other-collection)
5318 (url "https://example.org/second-collection.git")
5319 (branch "testing"))))
5322 In the above example this channel is declared to depend on two other channels,
5323 which will both be fetched automatically. The modules provided by the channel
5324 will be compiled in an environment where the modules of all these declared
5325 channels are available.
5327 For the sake of reliability and maintainability, you should avoid dependencies
5328 on channels that you don't control, and you should aim to keep the number of
5329 dependencies to a minimum.
5331 @node Specifying Channel Authorizations
5332 @section Specifying Channel Authorizations
5334 @cindex channel authorizations
5335 @anchor{channel-authorizations}
5336 As we saw above, Guix ensures the source code it pulls from channels
5337 comes from authorized developers. As a channel author, you need to
5338 specify the list of authorized developers in the
5339 @file{.guix-authorizations} file in the channel's Git repository. The
5340 authentication rule is simple: each commit must be signed by a key
5341 listed in the @file{.guix-authorizations} file of its parent
5342 commit(s)@footnote{Git commits form a @dfn{directed acyclic graph}
5343 (DAG). Each commit can have zero or more parents; ``regular'' commits
5344 have one parent and merge commits have two parent commits. Read
5345 @uref{https://eagain.net/articles/git-for-computer-scientists/, @i{Git
5346 for Computer Scientists}} for a great overview.} The
5347 @file{.guix-authorizations} file looks like this:
5350 ;; Example '.guix-authorizations' file.
5353 (version 0) ;current file format version
5355 (("AD17 A21E F8AE D8F1 CC02 DBD9 F8AE D8F1 765C 61E3"
5357 ("2A39 3FFF 68F4 EF7A 3D29 12AF 68F4 EF7A 22FB B2D5"
5359 ("CABB A931 C0FF EEC6 900D 0CFB 090B 1199 3D9A EBB5"
5363 Each fingerprint is followed by optional key/value pairs, as in the
5364 example above. Currently these key/value pairs are ignored.
5366 This authentication rule creates a chicken-and-egg issue: how do we
5367 authenticate the first commit? Related to that: how do we deal with
5368 channels whose repository history contains unsigned commits and lack
5369 @file{.guix-authorizations}? And how do we fork existing channels?
5371 @cindex channel introduction
5372 Channel introductions answer these questions by describing the first
5373 commit of a channel that should be authenticated. The first time a
5374 channel is fetched with @command{guix pull} or @command{guix
5375 time-machine}, the command looks up the introductory commit and verifies
5376 that it is signed by the specified OpenPGP key. From then on, it
5377 authenticates commits according to the rule above.
5379 Additionally, your channel must provide all the OpenPGP keys that were
5380 ever mentioned in @file{.guix-authorizations}, stored as @file{.key}
5381 files, which can be either binary or ``ASCII-armored''. By default,
5382 those @file{.key} files are searched for in the branch named
5383 @code{keyring} but you can specify a different branch name in
5384 @code{.guix-channel} like so:
5389 (keyring-reference "my-keyring-branch"))
5392 To summarize, as the author of a channel, there are three things you have
5393 to do to allow users to authenticate your code:
5397 Export the OpenPGP keys of past and present committers with @command{gpg
5398 --export} and store them in @file{.key} files, by default in a branch
5399 named @code{keyring} (we recommend making it an @dfn{orphan branch}).
5402 Introduce an initial @file{.guix-authorizations} in the channel's
5403 repository. Do that in a signed commit (@pxref{Commit Access}, for
5404 information on how to sign Git commits.)
5407 Advertise the channel introduction, for instance on your channel's web
5408 page. The channel introduction, as we saw above, is the commit/key
5409 pair---i.e., the commit that introduced @file{.guix-authorizations}, and
5410 the fingerprint of the OpenPGP used to sign it.
5413 Before pushing to your public Git repository, you can run @command{guix
5414 git-authenticate} to verify that you did sign all the commits you are
5415 about to push with an authorized key:
5418 guix git authenticate @var{commit} @var{signer}
5422 where @var{commit} and @var{signer} are your channel introduction.
5423 @xref{Invoking guix git authenticate}, for details.
5425 Publishing a signed channel requires discipline: any mistake, such as an
5426 unsigned commit or a commit signed by an unauthorized key, will prevent
5427 users from pulling from your channel---well, that's the whole point of
5428 authentication! Pay attention to merges in particular: merge commits
5429 are considered authentic if and only if they are signed by a key present
5430 in the @file{.guix-authorizations} file of @emph{both} branches.
5433 @section Primary URL
5435 @cindex primary URL, channels
5436 Channel authors can indicate the primary URL of their channel's Git
5437 repository in the @file{.guix-channel} file, like so:
5442 (url "https://example.org/guix.git"))
5445 This allows @command{guix pull} to determine whether it is pulling code
5446 from a mirror of the channel; when that is the case, it warns the user
5447 that the mirror might be stale and displays the primary URL@. That way,
5448 users cannot be tricked into fetching code from a stale mirror that does
5449 not receive security updates.
5451 This feature only makes sense for authenticated repositories, such as
5452 the official @code{guix} channel, for which @command{guix pull} ensures
5453 the code it fetches is authentic.
5455 @node Writing Channel News
5456 @section Writing Channel News
5458 @cindex news, for channels
5459 Channel authors may occasionally want to communicate to their users
5460 information about important changes in the channel. You'd send them all
5461 an email, but that's not convenient.
5463 Instead, channels can provide a @dfn{news file}; when the channel users
5464 run @command{guix pull}, that news file is automatically read and
5465 @command{guix pull --news} can display the announcements that correspond
5466 to the new commits that have been pulled, if any.
5468 To do that, channel authors must first declare the name of the news file
5469 in their @file{.guix-channel} file:
5474 (news-file "etc/news.txt"))
5477 The news file itself, @file{etc/news.txt} in this example, must look
5478 something like this:
5483 (entry (tag "the-bug-fix")
5484 (title (en "Fixed terrible bug")
5486 (body (en "@@emph@{Good news@}! It's fixed!")
5487 (eo "Certe ĝi pli bone funkcias nun!")))
5488 (entry (commit "bdcabe815cd28144a2d2b4bc3c5057b051fa9906")
5489 (title (en "Added a great package")
5490 (ca "Què vol dir guix?"))
5491 (body (en "Don't miss the @@code@{hello@} package!"))))
5494 While the news file is using the Scheme syntax, avoid naming it with a
5495 @file{.scm} extension or else it will get picked up when building the
5496 channel and yield an error since it is not a valid module.
5497 Alternatively, you can move the channel module to a subdirectory and
5498 store the news file in another directory.
5500 The file consists of a list of @dfn{news entries}. Each entry is
5501 associated with a commit or tag: it describes changes made in this
5502 commit, possibly in preceding commits as well. Users see entries only
5503 the first time they obtain the commit the entry refers to.
5505 The @code{title} field should be a one-line summary while @code{body}
5506 can be arbitrarily long, and both can contain Texinfo markup
5507 (@pxref{Overview,,, texinfo, GNU Texinfo}). Both the title and body are
5508 a list of language tag/message tuples, which allows @command{guix pull}
5509 to display news in the language that corresponds to the user's locale.
5511 If you want to translate news using a gettext-based workflow, you can
5512 extract translatable strings with @command{xgettext} (@pxref{xgettext
5513 Invocation,,, gettext, GNU Gettext Utilities}). For example, assuming
5514 you write news entries in English first, the command below creates a PO
5515 file containing the strings to translate:
5518 xgettext -o news.po -l scheme -ken etc/news.txt
5521 To sum up, yes, you could use your channel as a blog. But beware, this
5522 is @emph{not quite} what your users might expect.
5524 @c *********************************************************************
5526 @chapter Development
5528 @cindex software development
5529 If you are a software developer, Guix provides tools that you should find
5530 helpful---independently of the language you're developing in. This is what
5531 this chapter is about.
5533 The @command{guix environment} command provides a convenient way to set up
5534 @dfn{development environments} containing all the dependencies and tools
5535 necessary to work on the software package of your choice. The @command{guix
5536 pack} command allows you to create @dfn{application bundles} that can be
5537 easily distributed to users who do not run Guix.
5540 * Invoking guix environment:: Setting up development environments.
5541 * Invoking guix pack:: Creating software bundles.
5542 * The GCC toolchain:: Working with languages supported by GCC.
5543 * Invoking guix git authenticate:: Authenticating Git repositories.
5546 @node Invoking guix environment
5547 @section Invoking @command{guix environment}
5549 @cindex reproducible build environments
5550 @cindex development environments
5551 @cindex @command{guix environment}
5552 @cindex environment, package build environment
5553 The purpose of @command{guix environment} is to assist hackers in
5554 creating reproducible development environments without polluting their
5555 package profile. The @command{guix environment} tool takes one or more
5556 packages, builds all of their inputs, and creates a shell
5557 environment to use them.
5559 The general syntax is:
5562 guix environment @var{options} @var{package}@dots{}
5565 The following example spawns a new shell set up for the development of
5569 guix environment guile
5572 If the needed dependencies are not built yet, @command{guix environment}
5573 automatically builds them. The environment of the new shell is an
5574 augmented version of the environment that @command{guix environment} was
5575 run in. It contains the necessary search paths for building the given
5576 package added to the existing environment variables. To create
5577 a ``pure'' environment, in which the original environment variables have
5578 been unset, use the @option{--pure} option@footnote{Users sometimes
5579 wrongfully augment environment variables such as @env{PATH} in their
5580 @file{~/.bashrc} file. As a consequence, when @command{guix
5581 environment} launches it, Bash may read @file{~/.bashrc}, thereby
5582 introducing ``impurities'' in these environment variables. It is an
5583 error to define such environment variables in @file{.bashrc}; instead,
5584 they should be defined in @file{.bash_profile}, which is sourced only by
5585 log-in shells. @xref{Bash Startup Files,,, bash, The GNU Bash Reference
5586 Manual}, for details on Bash start-up files.}.
5588 Exiting from a Guix environment is the same as exiting from the shell,
5589 and will place the user back in the old environment before @command{guix
5590 environment} was invoked. The next garbage collection (@pxref{Invoking
5591 guix gc}) will clean up packages that were installed from within the
5592 environment and are no longer used outside of it.
5594 @vindex GUIX_ENVIRONMENT
5595 @command{guix environment} defines the @env{GUIX_ENVIRONMENT}
5596 variable in the shell it spawns; its value is the file name of the
5597 profile of this environment. This allows users to, say, define a
5598 specific prompt for development environments in their @file{.bashrc}
5599 (@pxref{Bash Startup Files,,, bash, The GNU Bash Reference Manual}):
5602 if [ -n "$GUIX_ENVIRONMENT" ]
5604 export PS1="\u@@\h \w [dev]\$ "
5609 ...@: or to browse the profile:
5612 $ ls "$GUIX_ENVIRONMENT/bin"
5615 Additionally, more than one package may be specified, in which case the
5616 union of the inputs for the given packages are used. For example, the
5617 command below spawns a shell where all of the dependencies of both Guile
5618 and Emacs are available:
5621 guix environment guile emacs
5624 Sometimes an interactive shell session is not desired. An arbitrary
5625 command may be invoked by placing the @code{--} token to separate the
5626 command from the rest of the arguments:
5629 guix environment guile -- make -j4
5632 In other situations, it is more convenient to specify the list of
5633 packages needed in the environment. For example, the following command
5634 runs @command{python} from an environment containing Python@tie{}2.7 and
5638 guix environment --ad-hoc python2-numpy python-2.7 -- python
5641 Furthermore, one might want the dependencies of a package and also some
5642 additional packages that are not build-time or runtime dependencies, but
5643 are useful when developing nonetheless. Because of this, the
5644 @option{--ad-hoc} flag is positional. Packages appearing before
5645 @option{--ad-hoc} are interpreted as packages whose dependencies will be
5646 added to the environment. Packages appearing after are interpreted as
5647 packages that will be added to the environment directly. For example,
5648 the following command creates a Guix development environment that
5649 additionally includes Git and strace:
5652 guix environment --pure guix --ad-hoc git strace
5656 Sometimes it is desirable to isolate the environment as much as
5657 possible, for maximal purity and reproducibility. In particular, when
5658 using Guix on a host distro that is not Guix System, it is desirable to
5659 prevent access to @file{/usr/bin} and other system-wide resources from
5660 the development environment. For example, the following command spawns
5661 a Guile REPL in a ``container'' where only the store and the current
5662 working directory are mounted:
5665 guix environment --ad-hoc --container guile -- guile
5669 The @option{--container} option requires Linux-libre 3.19 or newer.
5672 @cindex certificates
5673 Another typical use case for containers is to run security-sensitive
5674 applications such as a web browser. To run Eolie, we must expose and
5675 share some files and directories; we include @code{nss-certs} and expose
5676 @file{/etc/ssl/certs/} for HTTPS authentication; finally we preserve the
5677 @env{DISPLAY} environment variable since containerized graphical
5678 applications won't display without it.
5681 guix environment --preserve='^DISPLAY$' --container --network \
5682 --expose=/etc/machine-id \
5683 --expose=/etc/ssl/certs/ \
5684 --share=$HOME/.local/share/eolie/=$HOME/.local/share/eolie/ \
5685 --ad-hoc eolie nss-certs dbus -- eolie
5688 The available options are summarized below.
5691 @item --root=@var{file}
5692 @itemx -r @var{file}
5693 @cindex persistent environment
5694 @cindex garbage collector root, for environments
5695 Make @var{file} a symlink to the profile for this environment, and
5696 register it as a garbage collector root.
5698 This is useful if you want to protect your environment from garbage
5699 collection, to make it ``persistent''.
5701 When this option is omitted, the environment is protected from garbage
5702 collection only for the duration of the @command{guix environment}
5703 session. This means that next time you recreate the same environment,
5704 you could have to rebuild or re-download packages. @xref{Invoking guix
5705 gc}, for more on GC roots.
5707 @item --expression=@var{expr}
5708 @itemx -e @var{expr}
5709 Create an environment for the package or list of packages that
5710 @var{expr} evaluates to.
5712 For example, running:
5715 guix environment -e '(@@ (gnu packages maths) petsc-openmpi)'
5718 starts a shell with the environment for this specific variant of the
5724 guix environment --ad-hoc -e '(@@ (gnu) %base-packages)'
5727 starts a shell with all the base system packages available.
5729 The above commands only use the default output of the given packages.
5730 To select other outputs, two element tuples can be specified:
5733 guix environment --ad-hoc -e '(list (@@ (gnu packages bash) bash) "include")'
5736 @item --load=@var{file}
5737 @itemx -l @var{file}
5738 Create an environment for the package or list of packages that the code
5739 within @var{file} evaluates to.
5741 As an example, @var{file} might contain a definition like this
5742 (@pxref{Defining Packages}):
5745 @verbatiminclude environment-gdb.scm
5748 @item --manifest=@var{file}
5749 @itemx -m @var{file}
5750 Create an environment for the packages contained in the manifest object
5751 returned by the Scheme code in @var{file}. This option can be repeated
5752 several times, in which case the manifests are concatenated.
5754 This is similar to the same-named option in @command{guix package}
5755 (@pxref{profile-manifest, @option{--manifest}}) and uses the same
5759 Include all specified packages in the resulting environment, as if an
5760 @i{ad hoc} package were defined with them as inputs. This option is
5761 useful for quickly creating an environment without having to write a
5762 package expression to contain the desired inputs.
5764 For instance, the command:
5767 guix environment --ad-hoc guile guile-sdl -- guile
5770 runs @command{guile} in an environment where Guile and Guile-SDL are
5773 Note that this example implicitly asks for the default output of
5774 @code{guile} and @code{guile-sdl}, but it is possible to ask for a
5775 specific output---e.g., @code{glib:bin} asks for the @code{bin} output
5776 of @code{glib} (@pxref{Packages with Multiple Outputs}).
5778 This option may be composed with the default behavior of @command{guix
5779 environment}. Packages appearing before @option{--ad-hoc} are
5780 interpreted as packages whose dependencies will be added to the
5781 environment, the default behavior. Packages appearing after are
5782 interpreted as packages that will be added to the environment directly.
5785 Unset existing environment variables when building the new environment, except
5786 those specified with @option{--preserve} (see below). This has the effect of
5787 creating an environment in which search paths only contain package inputs.
5789 @item --preserve=@var{regexp}
5790 @itemx -E @var{regexp}
5791 When used alongside @option{--pure}, preserve the environment variables
5792 matching @var{regexp}---in other words, put them on a ``white list'' of
5793 environment variables that must be preserved. This option can be repeated
5797 guix environment --pure --preserve=^SLURM --ad-hoc openmpi @dots{} \
5801 This example runs @command{mpirun} in a context where the only environment
5802 variables defined are @env{PATH}, environment variables whose name starts
5803 with @samp{SLURM}, as well as the usual ``precious'' variables (@env{HOME},
5806 @item --search-paths
5807 Display the environment variable definitions that make up the
5810 @item --system=@var{system}
5811 @itemx -s @var{system}
5812 Attempt to build for @var{system}---e.g., @code{i686-linux}.
5817 Run @var{command} within an isolated container. The current working
5818 directory outside the container is mapped inside the container.
5819 Additionally, unless overridden with @option{--user}, a dummy home
5820 directory is created that matches the current user's home directory, and
5821 @file{/etc/passwd} is configured accordingly.
5823 The spawned process runs as the current user outside the container. Inside
5824 the container, it has the same UID and GID as the current user, unless
5825 @option{--user} is passed (see below).
5829 For containers, share the network namespace with the host system.
5830 Containers created without this flag only have access to the loopback
5833 @item --link-profile
5835 For containers, link the environment profile to @file{~/.guix-profile}
5836 within the container and set @code{GUIX_ENVIRONMENT} to that.
5837 This is equivalent to making @file{~/.guix-profile} a symlink to the
5838 actual profile within the container.
5839 Linking will fail and abort the environment if the directory already
5840 exists, which will certainly be the case if @command{guix environment}
5841 was invoked in the user's home directory.
5843 Certain packages are configured to look in @file{~/.guix-profile} for
5844 configuration files and data;@footnote{For example, the
5845 @code{fontconfig} package inspects @file{~/.guix-profile/share/fonts}
5846 for additional fonts.} @option{--link-profile} allows these programs to
5847 behave as expected within the environment.
5849 @item --user=@var{user}
5850 @itemx -u @var{user}
5851 For containers, use the username @var{user} in place of the current
5852 user. The generated @file{/etc/passwd} entry within the container will
5853 contain the name @var{user}, the home directory will be
5854 @file{/home/@var{user}}, and no user GECOS data will be copied. Furthermore,
5855 the UID and GID inside the container are 1000. @var{user}
5856 need not exist on the system.
5858 Additionally, any shared or exposed path (see @option{--share} and
5859 @option{--expose} respectively) whose target is within the current user's
5860 home directory will be remapped relative to @file{/home/USER}; this
5861 includes the automatic mapping of the current working directory.
5864 # will expose paths as /home/foo/wd, /home/foo/test, and /home/foo/target
5866 guix environment --container --user=foo \
5867 --expose=$HOME/test \
5868 --expose=/tmp/target=$HOME/target
5871 While this will limit the leaking of user identity through home paths
5872 and each of the user fields, this is only one useful component of a
5873 broader privacy/anonymity solution---not one in and of itself.
5876 For containers, the default behavior is to share the current working
5877 directory with the isolated container and immediately change to that
5878 directory within the container. If this is undesirable,
5879 @option{--no-cwd} will cause the current working directory to @emph{not}
5880 be automatically shared and will change to the user's home directory
5881 within the container instead. See also @option{--user}.
5883 @item --expose=@var{source}[=@var{target}]
5884 @itemx --share=@var{source}[=@var{target}]
5885 For containers, @option{--expose} (resp. @option{--share}) exposes the
5886 file system @var{source} from the host system as the read-only
5887 (resp. writable) file system @var{target} within the container. If
5888 @var{target} is not specified, @var{source} is used as the target mount
5889 point in the container.
5891 The example below spawns a Guile REPL in a container in which the user's
5892 home directory is accessible read-only via the @file{/exchange}
5896 guix environment --container --expose=$HOME=/exchange --ad-hoc guile -- guile
5901 @command{guix environment}
5902 also supports all of the common build options that @command{guix
5903 build} supports (@pxref{Common Build Options}) as well as package
5904 transformation options (@pxref{Package Transformation Options}).
5906 @node Invoking guix pack
5907 @section Invoking @command{guix pack}
5909 Occasionally you want to pass software to people who are not (yet!)
5910 lucky enough to be using Guix. You'd tell them to run @command{guix
5911 package -i @var{something}}, but that's not possible in this case. This
5912 is where @command{guix pack} comes in.
5915 If you are looking for ways to exchange binaries among machines that
5916 already run Guix, @pxref{Invoking guix copy}, @ref{Invoking guix
5917 publish}, and @ref{Invoking guix archive}.
5922 @cindex application bundle
5923 @cindex software bundle
5924 The @command{guix pack} command creates a shrink-wrapped @dfn{pack} or
5925 @dfn{software bundle}: it creates a tarball or some other archive
5926 containing the binaries of the software you're interested in, and all
5927 its dependencies. The resulting archive can be used on any machine that
5928 does not have Guix, and people can run the exact same binaries as those
5929 you have with Guix. The pack itself is created in a bit-reproducible
5930 fashion, so anyone can verify that it really contains the build results
5931 that you pretend to be shipping.
5933 For example, to create a bundle containing Guile, Emacs, Geiser, and all
5934 their dependencies, you can run:
5937 $ guix pack guile emacs geiser
5939 /gnu/store/@dots{}-pack.tar.gz
5942 The result here is a tarball containing a @file{/gnu/store} directory
5943 with all the relevant packages. The resulting tarball contains a
5944 @dfn{profile} with the three packages of interest; the profile is the
5945 same as would be created by @command{guix package -i}. It is this
5946 mechanism that is used to create Guix's own standalone binary tarball
5947 (@pxref{Binary Installation}).
5949 Users of this pack would have to run
5950 @file{/gnu/store/@dots{}-profile/bin/guile} to run Guile, which you may
5951 find inconvenient. To work around it, you can create, say, a
5952 @file{/opt/gnu/bin} symlink to the profile:
5955 guix pack -S /opt/gnu/bin=bin guile emacs geiser
5959 That way, users can happily type @file{/opt/gnu/bin/guile} and enjoy.
5961 @cindex relocatable binaries, with @command{guix pack}
5962 What if the recipient of your pack does not have root privileges on
5963 their machine, and thus cannot unpack it in the root file system? In
5964 that case, you will want to use the @option{--relocatable} option (see
5965 below). This option produces @dfn{relocatable binaries}, meaning they
5966 they can be placed anywhere in the file system hierarchy: in the example
5967 above, users can unpack your tarball in their home directory and
5968 directly run @file{./opt/gnu/bin/guile}.
5970 @cindex Docker, build an image with guix pack
5971 Alternatively, you can produce a pack in the Docker image format using
5972 the following command:
5975 guix pack -f docker -S /bin=bin guile guile-readline
5979 The result is a tarball that can be passed to the @command{docker load}
5980 command, followed by @code{docker run}:
5983 docker load < @var{file}
5984 docker run -ti guile-guile-readline /bin/guile
5988 where @var{file} is the image returned by @var{guix pack}, and
5989 @code{guile-guile-readline} is its ``image tag''. See the
5990 @uref{https://docs.docker.com/engine/reference/commandline/load/, Docker
5991 documentation} for more information.
5993 @cindex Singularity, build an image with guix pack
5994 @cindex SquashFS, build an image with guix pack
5995 Yet another option is to produce a SquashFS image with the following
5999 guix pack -f squashfs bash guile emacs geiser
6003 The result is a SquashFS file system image that can either be mounted or
6004 directly be used as a file system container image with the
6005 @uref{https://www.sylabs.io/docs/, Singularity container execution
6006 environment}, using commands like @command{singularity shell} or
6007 @command{singularity exec}.
6009 Several command-line options allow you to customize your pack:
6012 @item --format=@var{format}
6013 @itemx -f @var{format}
6014 Produce a pack in the given @var{format}.
6016 The available formats are:
6020 This is the default format. It produces a tarball containing all the
6021 specified binaries and symlinks.
6024 This produces a tarball that follows the
6025 @uref{https://github.com/docker/docker/blob/master/image/spec/v1.2.md,
6026 Docker Image Specification}. The ``repository name'' as it appears in
6027 the output of the @command{docker images} command is computed from
6028 package names passed on the command line or in the manifest file.
6031 This produces a SquashFS image containing all the specified binaries and
6032 symlinks, as well as empty mount points for virtual file systems like
6036 Singularity @emph{requires} you to provide @file{/bin/sh} in the image.
6037 For that reason, @command{guix pack -f squashfs} always implies @code{-S
6038 /bin=bin}. Thus, your @command{guix pack} invocation must always start
6039 with something like:
6042 guix pack -f squashfs bash @dots{}
6045 If you forget the @code{bash} (or similar) package, @command{singularity
6046 run} and @command{singularity exec} will fail with an unhelpful ``no
6047 such file or directory'' message.
6051 @cindex relocatable binaries
6054 Produce @dfn{relocatable binaries}---i.e., binaries that can be placed
6055 anywhere in the file system hierarchy and run from there.
6057 When this option is passed once, the resulting binaries require support for
6058 @dfn{user namespaces} in the kernel Linux; when passed
6059 @emph{twice}@footnote{Here's a trick to memorize it: @code{-RR}, which adds
6060 PRoot support, can be thought of as the abbreviation of ``Really
6061 Relocatable''. Neat, isn't it?}, relocatable binaries fall to back to
6062 other techniques if user namespaces are unavailable, and essentially
6063 work anywhere---see below for the implications.
6065 For example, if you create a pack containing Bash with:
6068 guix pack -RR -S /mybin=bin bash
6072 ...@: you can copy that pack to a machine that lacks Guix, and from your
6073 home directory as a normal user, run:
6081 In that shell, if you type @code{ls /gnu/store}, you'll notice that
6082 @file{/gnu/store} shows up and contains all the dependencies of
6083 @code{bash}, even though the machine actually lacks @file{/gnu/store}
6084 altogether! That is probably the simplest way to deploy Guix-built
6085 software on a non-Guix machine.
6088 By default, relocatable binaries rely on the @dfn{user namespace} feature of
6089 the kernel Linux, which allows unprivileged users to mount or change root.
6090 Old versions of Linux did not support it, and some GNU/Linux distributions
6093 To produce relocatable binaries that work even in the absence of user
6094 namespaces, pass @option{--relocatable} or @option{-R} @emph{twice}. In that
6095 case, binaries will try user namespace support and fall back to another
6096 @dfn{execution engine} if user namespaces are not supported. The
6097 following execution engines are supported:
6101 Try user namespaces and fall back to PRoot if user namespaces are not
6102 supported (see below).
6105 Try user namespaces and fall back to Fakechroot if user namespaces are
6106 not supported (see below).
6109 Run the program through user namespaces and abort if they are not
6113 Run through PRoot. The @uref{https://proot-me.github.io/, PRoot} program
6114 provides the necessary
6115 support for file system virtualization. It achieves that by using the
6116 @code{ptrace} system call on the running program. This approach has the
6117 advantage to work without requiring special kernel support, but it incurs
6118 run-time overhead every time a system call is made.
6121 Run through Fakechroot. @uref{https://github.com/dex4er/fakechroot/,
6122 Fakechroot} virtualizes file system accesses by intercepting calls to C
6123 library functions such as @code{open}, @code{stat}, @code{exec}, and so
6124 on. Unlike PRoot, it incurs very little overhead. However, it does not
6125 always work: for example, some file system accesses made from within the
6126 C library are not intercepted, and file system accesses made @i{via}
6127 direct syscalls are not intercepted either, leading to erratic behavior.
6130 @vindex GUIX_EXECUTION_ENGINE
6131 When running a wrapped program, you can explicitly request one of the
6132 execution engines listed above by setting the
6133 @env{GUIX_EXECUTION_ENGINE} environment variable accordingly.
6136 @cindex entry point, for Docker images
6137 @item --entry-point=@var{command}
6138 Use @var{command} as the @dfn{entry point} of the resulting pack, if the pack
6139 format supports it---currently @code{docker} and @code{squashfs} (Singularity)
6140 support it. @var{command} must be relative to the profile contained in the
6143 The entry point specifies the command that tools like @code{docker run} or
6144 @code{singularity run} automatically start by default. For example, you can
6148 guix pack -f docker --entry-point=bin/guile guile
6151 The resulting pack can easily be loaded and @code{docker run} with no extra
6152 arguments will spawn @code{bin/guile}:
6155 docker load -i pack.tar.gz
6156 docker run @var{image-id}
6159 @item --expression=@var{expr}
6160 @itemx -e @var{expr}
6161 Consider the package @var{expr} evaluates to.
6163 This has the same purpose as the same-named option in @command{guix
6164 build} (@pxref{Additional Build Options, @option{--expression} in
6165 @command{guix build}}).
6167 @item --manifest=@var{file}
6168 @itemx -m @var{file}
6169 Use the packages contained in the manifest object returned by the Scheme
6170 code in @var{file}. This option can be repeated several times, in which
6171 case the manifests are concatenated.
6173 This has a similar purpose as the same-named option in @command{guix
6174 package} (@pxref{profile-manifest, @option{--manifest}}) and uses the
6175 same manifest files. It allows you to define a collection of packages
6176 once and use it both for creating profiles and for creating archives
6177 for use on machines that do not have Guix installed. Note that you can
6178 specify @emph{either} a manifest file @emph{or} a list of packages,
6181 @item --system=@var{system}
6182 @itemx -s @var{system}
6183 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
6184 the system type of the build host.
6186 @item --target=@var{triplet}
6187 @cindex cross-compilation
6188 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
6189 as @code{"aarch64-linux-gnu"} (@pxref{Specifying target triplets, GNU
6190 configuration triplets,, autoconf, Autoconf}).
6192 @item --compression=@var{tool}
6193 @itemx -C @var{tool}
6194 Compress the resulting tarball using @var{tool}---one of @code{gzip},
6195 @code{zstd}, @code{bzip2}, @code{xz}, @code{lzip}, or @code{none} for no
6198 @item --symlink=@var{spec}
6199 @itemx -S @var{spec}
6200 Add the symlinks specified by @var{spec} to the pack. This option can
6201 appear several times.
6203 @var{spec} has the form @code{@var{source}=@var{target}}, where
6204 @var{source} is the symlink that will be created and @var{target} is the
6207 For instance, @code{-S /opt/gnu/bin=bin} creates a @file{/opt/gnu/bin}
6208 symlink pointing to the @file{bin} sub-directory of the profile.
6210 @item --save-provenance
6211 Save provenance information for the packages passed on the command line.
6212 Provenance information includes the URL and commit of the channels in use
6215 Provenance information is saved in the
6216 @file{/gnu/store/@dots{}-profile/manifest} file in the pack, along with the
6217 usual package metadata---the name and version of each package, their
6218 propagated inputs, and so on. It is useful information to the recipient of
6219 the pack, who then knows how the pack was (supposedly) obtained.
6221 This option is not enabled by default because, like timestamps, provenance
6222 information contributes nothing to the build process. In other words, there
6223 is an infinity of channel URLs and commit IDs that can lead to the same pack.
6224 Recording such ``silent'' metadata in the output thus potentially breaks the
6225 source-to-binary bitwise reproducibility property.
6227 @item --root=@var{file}
6228 @itemx -r @var{file}
6229 @cindex garbage collector root, for packs
6230 Make @var{file} a symlink to the resulting pack, and register it as a garbage
6233 @item --localstatedir
6234 @itemx --profile-name=@var{name}
6235 Include the ``local state directory'', @file{/var/guix}, in the resulting
6236 pack, and notably the @file{/var/guix/profiles/per-user/root/@var{name}}
6237 profile---by default @var{name} is @code{guix-profile}, which corresponds to
6238 @file{~root/.guix-profile}.
6240 @file{/var/guix} contains the store database (@pxref{The Store}) as well
6241 as garbage-collector roots (@pxref{Invoking guix gc}). Providing it in
6242 the pack means that the store is ``complete'' and manageable by Guix;
6243 not providing it pack means that the store is ``dead'': items cannot be
6244 added to it or removed from it after extraction of the pack.
6246 One use case for this is the Guix self-contained binary tarball
6247 (@pxref{Binary Installation}).
6251 Print the name of the derivation that builds the pack.
6254 Use the bootstrap binaries to build the pack. This option is only
6255 useful to Guix developers.
6258 In addition, @command{guix pack} supports all the common build options
6259 (@pxref{Common Build Options}) and all the package transformation
6260 options (@pxref{Package Transformation Options}).
6263 @node The GCC toolchain
6264 @section The GCC toolchain
6268 @cindex linker wrapper
6269 @cindex toolchain, for C development
6270 @cindex toolchain, for Fortran development
6272 If you need a complete toolchain for compiling and linking C or C++
6273 source code, use the @code{gcc-toolchain} package. This package
6274 provides a complete GCC toolchain for C/C++ development, including GCC
6275 itself, the GNU C Library (headers and binaries, plus debugging symbols
6276 in the @code{debug} output), Binutils, and a linker wrapper.
6278 The wrapper's purpose is to inspect the @code{-L} and @code{-l} switches
6279 passed to the linker, add corresponding @code{-rpath} arguments, and
6280 invoke the actual linker with this new set of arguments. You can instruct the
6281 wrapper to refuse to link against libraries not in the store by setting the
6282 @env{GUIX_LD_WRAPPER_ALLOW_IMPURITIES} environment variable to @code{no}.
6284 The package @code{gfortran-toolchain} provides a complete GCC toolchain
6285 for Fortran development. For other languages, please use
6286 @samp{guix search gcc toolchain} (@pxref{guix-search,, Invoking guix package}).
6289 @node Invoking guix git authenticate
6290 @section Invoking @command{guix git authenticate}
6292 The @command{guix git authenticate} command authenticates a Git checkout
6293 following the same rule as for channels (@pxref{channel-authentication,
6294 channel authentication}). That is, starting from a given commit, it
6295 ensures that all subsequent commits are signed by an OpenPGP key whose
6296 fingerprint appears in the @file{.guix-authorizations} file of its
6299 You will find this command useful if you maintain a channel. But in
6300 fact, this authentication mechanism is useful in a broader context, so
6301 you might want to use it for Git repositories that have nothing to do
6304 The general syntax is:
6307 guix git authenticate @var{commit} @var{signer} [@var{options}@dots{}]
6310 By default, this command authenticates the Git checkout in the current
6311 directory; it outputs nothing and exits with exit code zero on success
6312 and non-zero on failure. @var{commit} above denotes the first commit
6313 where authentication takes place, and @var{signer} is the OpenPGP
6314 fingerprint of public key used to sign @var{commit}. Together, they
6315 form a ``channel introduction'' (@pxref{channel-authentication, channel
6316 introduction}). The options below allow you to fine-tune the process.
6319 @item --repository=@var{directory}
6320 @itemx -r @var{directory}
6321 Open the Git repository in @var{directory} instead of the current
6324 @item --keyring=@var{reference}
6325 @itemx -k @var{reference}
6326 Load OpenPGP keyring from @var{reference}, the reference of a branch
6327 such as @code{origin/keyring} or @code{my-keyring}. The branch must
6328 contain OpenPGP public keys in @file{.key} files, either in binary form
6329 or ``ASCII-armored''. By default the keyring is loaded from the branch
6330 named @code{keyring}.
6333 Display commit signing statistics upon completion.
6335 @item --cache-key=@var{key}
6336 Previously-authenticated commits are cached in a file under
6337 @file{~/.cache/guix/authentication}. This option forces the cache to be
6338 stored in file @var{key} in that directory.
6340 @item --historical-authorizations=@var{file}
6341 By default, any commit whose parent commit(s) lack the
6342 @file{.guix-authorizations} file is considered inauthentic. In
6343 contrast, this option considers the authorizations in @var{file} for any
6344 commit that lacks @file{.guix-authorizations}. The format of @var{file}
6345 is the same as that of @file{.guix-authorizations}
6346 (@pxref{channel-authorizations, @file{.guix-authorizations} format}).
6350 @c *********************************************************************
6351 @node Programming Interface
6352 @chapter Programming Interface
6354 GNU Guix provides several Scheme programming interfaces (APIs) to
6355 define, build, and query packages. The first interface allows users to
6356 write high-level package definitions. These definitions refer to
6357 familiar packaging concepts, such as the name and version of a package,
6358 its build system, and its dependencies. These definitions can then be
6359 turned into concrete build actions.
6361 Build actions are performed by the Guix daemon, on behalf of users. In a
6362 standard setup, the daemon has write access to the store---the
6363 @file{/gnu/store} directory---whereas users do not. The recommended
6364 setup also has the daemon perform builds in chroots, under specific
6365 build users, to minimize interference with the rest of the system.
6368 Lower-level APIs are available to interact with the daemon and the
6369 store. To instruct the daemon to perform a build action, users actually
6370 provide it with a @dfn{derivation}. A derivation is a low-level
6371 representation of the build actions to be taken, and the environment in
6372 which they should occur---derivations are to package definitions what
6373 assembly is to C programs. The term ``derivation'' comes from the fact
6374 that build results @emph{derive} from them.
6376 This chapter describes all these APIs in turn, starting from high-level
6377 package definitions.
6380 * Package Modules:: Packages from the programmer's viewpoint.
6381 * Defining Packages:: Defining new packages.
6382 * Defining Package Variants:: Customizing packages.
6383 * Build Systems:: Specifying how packages are built.
6384 * Build Phases:: Phases of the build process of a package.
6385 * Build Utilities:: Helpers for your package definitions and more.
6386 * The Store:: Manipulating the package store.
6387 * Derivations:: Low-level interface to package derivations.
6388 * The Store Monad:: Purely functional interface to the store.
6389 * G-Expressions:: Manipulating build expressions.
6390 * Invoking guix repl:: Programming Guix in Guile
6393 @node Package Modules
6394 @section Package Modules
6396 From a programming viewpoint, the package definitions of the
6397 GNU distribution are provided by Guile modules in the @code{(gnu packages
6398 @dots{})} name space@footnote{Note that packages under the @code{(gnu
6399 packages @dots{})} module name space are not necessarily ``GNU
6400 packages''. This module naming scheme follows the usual Guile module
6401 naming convention: @code{gnu} means that these modules are distributed
6402 as part of the GNU system, and @code{packages} identifies modules that
6403 define packages.} (@pxref{Modules, Guile modules,, guile, GNU Guile
6404 Reference Manual}). For instance, the @code{(gnu packages emacs)}
6405 module exports a variable named @code{emacs}, which is bound to a
6406 @code{<package>} object (@pxref{Defining Packages}).
6408 The @code{(gnu packages @dots{})} module name space is
6409 automatically scanned for packages by the command-line tools. For
6410 instance, when running @code{guix install emacs}, all the @code{(gnu
6411 packages @dots{})} modules are scanned until one that exports a package
6412 object whose name is @code{emacs} is found. This package search
6413 facility is implemented in the @code{(gnu packages)} module.
6415 @cindex customization, of packages
6416 @cindex package module search path
6417 Users can store package definitions in modules with different
6418 names---e.g., @code{(my-packages emacs)}@footnote{Note that the file
6419 name and module name must match. For instance, the @code{(my-packages
6420 emacs)} module must be stored in a @file{my-packages/emacs.scm} file
6421 relative to the load path specified with @option{--load-path} or
6422 @env{GUIX_PACKAGE_PATH}. @xref{Modules and the File System,,,
6423 guile, GNU Guile Reference Manual}, for details.}. There are two ways to make
6424 these package definitions visible to the user interfaces:
6428 By adding the directory containing your package modules to the search path
6429 with the @code{-L} flag of @command{guix package} and other commands
6430 (@pxref{Common Build Options}), or by setting the @env{GUIX_PACKAGE_PATH}
6431 environment variable described below.
6434 By defining a @dfn{channel} and configuring @command{guix pull} so that it
6435 pulls from it. A channel is essentially a Git repository containing package
6436 modules. @xref{Channels}, for more information on how to define and use
6440 @env{GUIX_PACKAGE_PATH} works similarly to other search path variables:
6442 @defvr {Environment Variable} GUIX_PACKAGE_PATH
6443 This is a colon-separated list of directories to search for additional
6444 package modules. Directories listed in this variable take precedence
6445 over the own modules of the distribution.
6448 The distribution is fully @dfn{bootstrapped} and @dfn{self-contained}:
6449 each package is built based solely on other packages in the
6450 distribution. The root of this dependency graph is a small set of
6451 @dfn{bootstrap binaries}, provided by the @code{(gnu packages
6452 bootstrap)} module. For more information on bootstrapping,
6453 @pxref{Bootstrapping}.
6455 @node Defining Packages
6456 @section Defining Packages
6458 The high-level interface to package definitions is implemented in the
6459 @code{(guix packages)} and @code{(guix build-system)} modules. As an
6460 example, the package definition, or @dfn{recipe}, for the GNU Hello
6461 package looks like this:
6464 (define-module (gnu packages hello)
6465 #:use-module (guix packages)
6466 #:use-module (guix download)
6467 #:use-module (guix build-system gnu)
6468 #:use-module (guix licenses)
6469 #:use-module (gnu packages gawk))
6471 (define-public hello
6477 (uri (string-append "mirror://gnu/hello/hello-" version
6481 "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
6482 (build-system gnu-build-system)
6483 (arguments '(#:configure-flags '("--enable-silent-rules")))
6484 (inputs `(("gawk" ,gawk)))
6485 (synopsis "Hello, GNU world: An example GNU package")
6486 (description "Guess what GNU Hello prints!")
6487 (home-page "https://www.gnu.org/software/hello/")
6492 Without being a Scheme expert, the reader may have guessed the meaning
6493 of the various fields here. This expression binds the variable
6494 @code{hello} to a @code{<package>} object, which is essentially a record
6495 (@pxref{SRFI-9, Scheme records,, guile, GNU Guile Reference Manual}).
6496 This package object can be inspected using procedures found in the
6497 @code{(guix packages)} module; for instance, @code{(package-name hello)}
6498 returns---surprise!---@code{"hello"}.
6500 With luck, you may be able to import part or all of the definition of
6501 the package you are interested in from another repository, using the
6502 @code{guix import} command (@pxref{Invoking guix import}).
6504 In the example above, @code{hello} is defined in a module of its own,
6505 @code{(gnu packages hello)}. Technically, this is not strictly
6506 necessary, but it is convenient to do so: all the packages defined in
6507 modules under @code{(gnu packages @dots{})} are automatically known to
6508 the command-line tools (@pxref{Package Modules}).
6510 There are a few points worth noting in the above package definition:
6514 The @code{source} field of the package is an @code{<origin>} object
6515 (@pxref{origin Reference}, for the complete reference).
6516 Here, the @code{url-fetch} method from @code{(guix download)} is used,
6517 meaning that the source is a file to be downloaded over FTP or HTTP.
6519 The @code{mirror://gnu} prefix instructs @code{url-fetch} to use one of
6520 the GNU mirrors defined in @code{(guix download)}.
6522 The @code{sha256} field specifies the expected SHA256 hash of the file
6523 being downloaded. It is mandatory, and allows Guix to check the
6524 integrity of the file. The @code{(base32 @dots{})} form introduces the
6525 base32 representation of the hash. You can obtain this information with
6526 @code{guix download} (@pxref{Invoking guix download}) and @code{guix
6527 hash} (@pxref{Invoking guix hash}).
6530 When needed, the @code{origin} form can also have a @code{patches} field
6531 listing patches to be applied, and a @code{snippet} field giving a
6532 Scheme expression to modify the source code.
6535 @cindex GNU Build System
6536 The @code{build-system} field specifies the procedure to build the
6537 package (@pxref{Build Systems}). Here, @code{gnu-build-system}
6538 represents the familiar GNU Build System, where packages may be
6539 configured, built, and installed with the usual @code{./configure &&
6540 make && make check && make install} command sequence.
6542 When you start packaging non-trivial software, you may need tools to
6543 manipulate those build phases, manipulate files, and so on. @xref{Build
6544 Utilities}, for more on this.
6547 The @code{arguments} field specifies options for the build system
6548 (@pxref{Build Systems}). Here it is interpreted by
6549 @code{gnu-build-system} as a request run @file{configure} with the
6550 @option{--enable-silent-rules} flag.
6556 What about these quote (@code{'}) characters? They are Scheme syntax to
6557 introduce a literal list; @code{'} is synonymous with @code{quote}.
6558 @xref{Expression Syntax, quoting,, guile, GNU Guile Reference Manual},
6559 for details. Here the value of the @code{arguments} field is a list of
6560 arguments passed to the build system down the road, as with @code{apply}
6561 (@pxref{Fly Evaluation, @code{apply},, guile, GNU Guile Reference
6564 The hash-colon (@code{#:}) sequence defines a Scheme @dfn{keyword}
6565 (@pxref{Keywords,,, guile, GNU Guile Reference Manual}), and
6566 @code{#:configure-flags} is a keyword used to pass a keyword argument
6567 to the build system (@pxref{Coding With Keywords,,, guile, GNU Guile
6571 The @code{inputs} field specifies inputs to the build process---i.e.,
6572 build-time or run-time dependencies of the package. Here, we define an
6573 input called @code{"gawk"} whose value is that of the @code{gawk}
6574 variable; @code{gawk} is itself bound to a @code{<package>} object.
6576 @cindex backquote (quasiquote)
6579 @cindex comma (unquote)
6583 @findex unquote-splicing
6584 Again, @code{`} (a backquote, synonymous with @code{quasiquote}) allows
6585 us to introduce a literal list in the @code{inputs} field, while
6586 @code{,} (a comma, synonymous with @code{unquote}) allows us to insert a
6587 value in that list (@pxref{Expression Syntax, unquote,, guile, GNU Guile
6590 Note that GCC, Coreutils, Bash, and other essential tools do not need to
6591 be specified as inputs here. Instead, @code{gnu-build-system} takes care
6592 of ensuring that they are present (@pxref{Build Systems}).
6594 However, any other dependencies need to be specified in the
6595 @code{inputs} field. Any dependency not specified here will simply be
6596 unavailable to the build process, possibly leading to a build failure.
6599 @xref{package Reference}, for a full description of possible fields.
6601 Once a package definition is in place, the
6602 package may actually be built using the @code{guix build} command-line
6603 tool (@pxref{Invoking guix build}), troubleshooting any build failures
6604 you encounter (@pxref{Debugging Build Failures}). You can easily jump back to the
6605 package definition using the @command{guix edit} command
6606 (@pxref{Invoking guix edit}).
6607 @xref{Packaging Guidelines}, for
6608 more information on how to test package definitions, and
6609 @ref{Invoking guix lint}, for information on how to check a definition
6610 for style conformance.
6611 @vindex GUIX_PACKAGE_PATH
6612 Lastly, @pxref{Channels}, for information
6613 on how to extend the distribution by adding your own package definitions
6616 Finally, updating the package definition to a new upstream version
6617 can be partly automated by the @command{guix refresh} command
6618 (@pxref{Invoking guix refresh}).
6620 Behind the scenes, a derivation corresponding to the @code{<package>}
6621 object is first computed by the @code{package-derivation} procedure.
6622 That derivation is stored in a @file{.drv} file under @file{/gnu/store}.
6623 The build actions it prescribes may then be realized by using the
6624 @code{build-derivations} procedure (@pxref{The Store}).
6626 @deffn {Scheme Procedure} package-derivation @var{store} @var{package} [@var{system}]
6627 Return the @code{<derivation>} object of @var{package} for @var{system}
6628 (@pxref{Derivations}).
6630 @var{package} must be a valid @code{<package>} object, and @var{system}
6631 must be a string denoting the target system type---e.g.,
6632 @code{"x86_64-linux"} for an x86_64 Linux-based GNU system. @var{store}
6633 must be a connection to the daemon, which operates on the store
6634 (@pxref{The Store}).
6638 @cindex cross-compilation
6639 Similarly, it is possible to compute a derivation that cross-builds a
6640 package for some other system:
6642 @deffn {Scheme Procedure} package-cross-derivation @var{store} @
6643 @var{package} @var{target} [@var{system}]
6644 Return the @code{<derivation>} object of @var{package} cross-built from
6645 @var{system} to @var{target}.
6647 @var{target} must be a valid GNU triplet denoting the target hardware
6648 and operating system, such as @code{"aarch64-linux-gnu"}
6649 (@pxref{Specifying Target Triplets,,, autoconf, Autoconf}).
6652 Once you have package definitions, you can easily define @emph{variants}
6653 of those packages. @xref{Defining Package Variants}, for more on that.
6656 * package Reference:: The package data type.
6657 * origin Reference:: The origin data type.
6661 @node package Reference
6662 @subsection @code{package} Reference
6664 This section summarizes all the options available in @code{package}
6665 declarations (@pxref{Defining Packages}).
6667 @deftp {Data Type} package
6668 This is the data type representing a package recipe.
6672 The name of the package, as a string.
6674 @item @code{version}
6675 The version of the package, as a string.
6678 An object telling how the source code for the package should be
6679 acquired. Most of the time, this is an @code{origin} object, which
6680 denotes a file fetched from the Internet (@pxref{origin Reference}). It
6681 can also be any other ``file-like'' object such as a @code{local-file},
6682 which denotes a file from the local file system (@pxref{G-Expressions,
6683 @code{local-file}}).
6685 @item @code{build-system}
6686 The build system that should be used to build the package (@pxref{Build
6689 @item @code{arguments} (default: @code{'()})
6690 The arguments that should be passed to the build system. This is a
6691 list, typically containing sequential keyword-value pairs.
6693 @item @code{inputs} (default: @code{'()})
6694 @itemx @code{native-inputs} (default: @code{'()})
6695 @itemx @code{propagated-inputs} (default: @code{'()})
6696 @cindex inputs, of packages
6697 These fields list dependencies of the package. Each one is a list of
6698 tuples, where each tuple has a label for the input (a string) as its
6699 first element, a package, origin, or derivation as its second element,
6700 and optionally the name of the output thereof that should be used, which
6701 defaults to @code{"out"} (@pxref{Packages with Multiple Outputs}, for
6702 more on package outputs). For example, the list below specifies three
6706 `(("libffi" ,libffi)
6707 ("libunistring" ,libunistring)
6708 ("glib:bin" ,glib "bin")) ;the "bin" output of Glib
6711 @cindex cross compilation, package dependencies
6712 The distinction between @code{native-inputs} and @code{inputs} is
6713 necessary when considering cross-compilation. When cross-compiling,
6714 dependencies listed in @code{inputs} are built for the @emph{target}
6715 architecture; conversely, dependencies listed in @code{native-inputs}
6716 are built for the architecture of the @emph{build} machine.
6718 @code{native-inputs} is typically used to list tools needed at
6719 build time, but not at run time, such as Autoconf, Automake, pkg-config,
6720 Gettext, or Bison. @command{guix lint} can report likely mistakes in
6721 this area (@pxref{Invoking guix lint}).
6723 @anchor{package-propagated-inputs}
6724 Lastly, @code{propagated-inputs} is similar to @code{inputs}, but the
6725 specified packages will be automatically installed to profiles
6726 (@pxref{Features, the role of profiles in Guix}) alongside the package
6727 they belong to (@pxref{package-cmd-propagated-inputs, @command{guix
6728 package}}, for information on how @command{guix package} deals with
6731 For example this is necessary when packaging a C/C++ library that needs
6732 headers of another library to compile, or when a pkg-config file refers
6733 to another one @i{via} its @code{Requires} field.
6735 Another example where @code{propagated-inputs} is useful is for languages
6736 that lack a facility to record the run-time search path akin to the
6737 @code{RUNPATH} of ELF files; this includes Guile, Python, Perl, and
6738 more. When packaging libraries written in those languages, ensure they
6739 can find library code they depend on at run time by listing run-time
6740 dependencies in @code{propagated-inputs} rather than @code{inputs}.
6742 @item @code{outputs} (default: @code{'("out")})
6743 The list of output names of the package. @xref{Packages with Multiple
6744 Outputs}, for typical uses of additional outputs.
6746 @item @code{native-search-paths} (default: @code{'()})
6747 @itemx @code{search-paths} (default: @code{'()})
6748 A list of @code{search-path-specification} objects describing
6749 search-path environment variables honored by the package.
6751 @item @code{replacement} (default: @code{#f})
6752 This must be either @code{#f} or a package object that will be used as a
6753 @dfn{replacement} for this package. @xref{Security Updates, grafts},
6756 @item @code{synopsis}
6757 A one-line description of the package.
6759 @item @code{description}
6760 A more elaborate description of the package.
6762 @item @code{license}
6763 @cindex license, of packages
6764 The license of the package; a value from @code{(guix licenses)},
6765 or a list of such values.
6767 @item @code{home-page}
6768 The URL to the home-page of the package, as a string.
6770 @item @code{supported-systems} (default: @code{%supported-systems})
6771 The list of systems supported by the package, as strings of the form
6772 @code{architecture-kernel}, for example @code{"x86_64-linux"}.
6774 @item @code{location} (default: source location of the @code{package} form)
6775 The source location of the package. It is useful to override this when
6776 inheriting from another package, in which case this field is not
6777 automatically corrected.
6781 @deffn {Scheme Syntax} this-package
6782 When used in the @emph{lexical scope} of a package field definition, this
6783 identifier resolves to the package being defined.
6785 The example below shows how to add a package as a native input of itself when
6793 ;; When cross-compiled, Guile, for example, depends on
6794 ;; a native version of itself. Add it here.
6795 (native-inputs (if (%current-target-system)
6796 `(("self" ,this-package))
6800 It is an error to refer to @code{this-package} outside a package definition.
6803 Because packages are regular Scheme objects that capture a complete
6804 dependency graph and associated build procedures, it is often useful to
6805 write procedures that take a package and return a modified version
6806 thereof according to some parameters. Below are a few examples.
6808 @cindex tool chain, choosing a package's tool chain
6809 @deffn {Scheme Procedure} package-with-c-toolchain @var{package} @var{toolchain}
6810 Return a variant of @var{package} that uses @var{toolchain} instead of
6811 the default GNU C/C++ toolchain. @var{toolchain} must be a list of
6812 inputs (label/package tuples) providing equivalent functionality, such
6813 as the @code{gcc-toolchain} package.
6815 The example below returns a variant of the @code{hello} package built
6816 with GCC@tie{}10.x and the rest of the GNU tool chain (Binutils and the
6817 GNU C Library) instead of the default tool chain:
6820 (let ((toolchain (specification->package "gcc-toolchain@@10")))
6821 (package-with-c-toolchain hello `(("toolchain" ,toolchain))))
6824 The build tool chain is part of the @dfn{implicit inputs} of
6825 packages---it's usually not listed as part of the various ``inputs''
6826 fields and is instead pulled in by the build system. Consequently, this
6827 procedure works by changing the build system of @var{package} so that it
6828 pulls in @var{toolchain} instead of the defaults. @ref{Build Systems},
6829 for more on build systems.
6832 @node origin Reference
6833 @subsection @code{origin} Reference
6835 This section documents @dfn{origins}. An @code{origin} declaration
6836 specifies data that must be ``produced''---downloaded, usually---and
6837 whose content hash is known in advance. Origins are primarily used to
6838 represent the source code of packages (@pxref{Defining Packages}). For
6839 that reason, the @code{origin} form allows you to declare patches to
6840 apply to the original source code as well as code snippets to modify it.
6842 @deftp {Data Type} origin
6843 This is the data type representing a source code origin.
6847 An object containing the URI of the source. The object type depends on
6848 the @code{method} (see below). For example, when using the
6849 @var{url-fetch} method of @code{(guix download)}, the valid @code{uri}
6850 values are: a URL represented as a string, or a list thereof.
6852 @cindex fixed-output derivations, for download
6854 A monadic procedure that handles the given URI@. The procedure must
6855 accept at least three arguments: the value of the @code{uri} field and
6856 the hash algorithm and hash value specified by the @code{hash} field.
6857 It must return a store item or a derivation in the store monad
6858 (@pxref{The Store Monad}); most methods return a fixed-output derivation
6859 (@pxref{Derivations}).
6861 Commonly used methods include @code{url-fetch}, which fetches data from
6862 a URL, and @code{git-fetch}, which fetches data from a Git repository
6866 A bytevector containing the SHA-256 hash of the source. This is
6867 equivalent to providing a @code{content-hash} SHA256 object in the
6868 @code{hash} field described below.
6871 The @code{content-hash} object of the source---see below for how to use
6872 @code{content-hash}.
6874 You can obtain this information using @code{guix download}
6875 (@pxref{Invoking guix download}) or @code{guix hash} (@pxref{Invoking
6878 @item @code{file-name} (default: @code{#f})
6879 The file name under which the source code should be saved. When this is
6880 @code{#f}, a sensible default value will be used in most cases. In case
6881 the source is fetched from a URL, the file name from the URL will be
6882 used. For version control checkouts, it is recommended to provide the
6883 file name explicitly because the default is not very descriptive.
6885 @item @code{patches} (default: @code{'()})
6886 A list of file names, origins, or file-like objects (@pxref{G-Expressions,
6887 file-like objects}) pointing to patches to be applied to the source.
6889 This list of patches must be unconditional. In particular, it cannot
6890 depend on the value of @code{%current-system} or
6891 @code{%current-target-system}.
6893 @item @code{snippet} (default: @code{#f})
6894 A G-expression (@pxref{G-Expressions}) or S-expression that will be run
6895 in the source directory. This is a convenient way to modify the source,
6896 sometimes more convenient than a patch.
6898 @item @code{patch-flags} (default: @code{'("-p1")})
6899 A list of command-line flags that should be passed to the @code{patch}
6902 @item @code{patch-inputs} (default: @code{#f})
6903 Input packages or derivations to the patching process. When this is
6904 @code{#f}, the usual set of inputs necessary for patching are provided,
6905 such as GNU@tie{}Patch.
6907 @item @code{modules} (default: @code{'()})
6908 A list of Guile modules that should be loaded during the patching
6909 process and while running the code in the @code{snippet} field.
6911 @item @code{patch-guile} (default: @code{#f})
6912 The Guile package that should be used in the patching process. When
6913 this is @code{#f}, a sensible default is used.
6917 @deftp {Data Type} content-hash @var{value} [@var{algorithm}]
6918 Construct a content hash object for the given @var{algorithm}, and with
6919 @var{value} as its hash value. When @var{algorithm} is omitted, assume
6920 it is @code{sha256}.
6922 @var{value} can be a literal string, in which case it is base32-decoded,
6923 or it can be a bytevector.
6925 The following forms are all equivalent:
6928 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj")
6929 (content-hash "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"
6931 (content-hash (base32
6932 "05zxkyz9bv3j9h0xyid1rhvh3klhsmrpkf3bcs6frvlgyr2gwilj"))
6933 (content-hash (base64 "kkb+RPaP7uyMZmu4eXPVkM4BN8yhRd8BTHLslb6f/Rc=")
6937 Technically, @code{content-hash} is currently implemented as a macro.
6938 It performs sanity checks at macro-expansion time, when possible, such
6939 as ensuring that @var{value} has the right size for @var{algorithm}.
6942 As we have seen above, how exactly the data an origin refers to is
6943 retrieved is determined by its @code{method} field. The @code{(guix
6944 download)} module provides the most common method, @code{url-fetch},
6947 @deffn {Scheme Procedure} url-fetch @var{url} @var{hash-algo} @var{hash} @
6948 [name] [#:executable? #f]
6949 Return a fixed-output derivation that fetches data from @var{url} (a
6950 string, or a list of strings denoting alternate URLs), which is expected
6951 to have hash @var{hash} of type @var{hash-algo} (a symbol). By default,
6952 the file name is the base name of URL; optionally, @var{name} can
6953 specify a different file name. When @var{executable?} is true, make the
6954 downloaded file executable.
6956 When one of the URL starts with @code{mirror://}, then its host part is
6957 interpreted as the name of a mirror scheme, taken from @file{%mirror-file}.
6959 Alternatively, when URL starts with @code{file://}, return the
6960 corresponding file name in the store.
6963 Likewise, the @code{(guix git-download)} module defines the
6964 @code{git-fetch} origin method, which fetches data from a Git version
6965 control repository, and the @code{git-reference} data type to describe
6966 the repository and revision to fetch.
6968 @deffn {Scheme Procedure} git-fetch @var{ref} @var{hash-algo} @var{hash}
6969 Return a fixed-output derivation that fetches @var{ref}, a
6970 @code{<git-reference>} object. The output is expected to have recursive
6971 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
6972 the file name, or a generic name if @code{#f}.
6975 @deftp {Data Type} git-reference
6976 This data type represents a Git reference for @code{git-fetch} to
6981 The URL of the Git repository to clone.
6984 This string denotes either the commit to fetch (a hexadecimal string,
6985 either the full SHA1 commit or a ``short'' commit string; the latter is
6986 not recommended) or the tag to fetch.
6988 @item @code{recursive?} (default: @code{#f})
6989 This Boolean indicates whether to recursively fetch Git sub-modules.
6992 The example below denotes the @code{v2.10} tag of the GNU@tie{}Hello
6997 (url "https://git.savannah.gnu.org/git/hello.git")
7001 This is equivalent to the reference below, which explicitly names the
7006 (url "https://git.savannah.gnu.org/git/hello.git")
7007 (commit "dc7dc56a00e48fe6f231a58f6537139fe2908fb9"))
7011 For Mercurial repositories, the module @code{(guix hg-download)} defines
7012 the @code{hg-fetch} origin method and @code{hg-reference} data type for
7013 support of the Mercurial version control system.
7015 @deffn {Scheme Procedure} hg-fetch @var{ref} @var{hash-algo} @var{hash} @
7017 Return a fixed-output derivation that fetches @var{ref}, a
7018 @code{<hg-reference>} object. The output is expected to have recursive
7019 hash @var{hash} of type @var{hash-algo} (a symbol). Use @var{name} as
7020 the file name, or a generic name if @code{#false}.
7023 @node Defining Package Variants
7024 @section Defining Package Variants
7026 @cindex customizing packages
7027 @cindex variants, of packages
7028 One of the nice things with Guix is that, given a package definition,
7029 you can easily @emph{derive} variants of that package---for a different
7030 upstream version, with different dependencies, different compilation
7031 options, and so on. Some of these custom packages can be defined
7032 straight from the command line (@pxref{Package Transformation Options}).
7033 This section describes how to define package variants in code. This can
7034 be useful in ``manifests'' (@pxref{profile-manifest,
7035 @option{--manifest}}) and in your own package collection
7036 (@pxref{Creating a Channel}), among others!
7038 @cindex inherit, for package definitions
7039 As discussed earlier, packages are first-class objects in the Scheme
7040 language. The @code{(guix packages)} module provides the @code{package}
7041 construct to define new package objects (@pxref{package Reference}).
7042 The easiest way to define a package variant is using the @code{inherit}
7043 keyword together with @code{package}. This allows you to inherit from a
7044 package definition while overriding the fields you want.
7046 For example, given the @code{hello} variable, which contains a
7047 definition for the current version of GNU@tie{}Hello, here's how you
7048 would define a variant for version 2.2 (released in 2006, it's
7052 (use-modules (gnu packages base)) ;for 'hello'
7060 (uri (string-append "mirror://gnu/hello/hello-" version
7064 "0lappv4slgb5spyqbh6yl5r013zv72yqg2pcl30mginf3wdqd8k9"))))))
7067 The example above corresponds to what the @option{--with-source} package
7068 transformation option does. Essentially @code{hello-2.2} preserves all
7069 the fields of @code{hello}, except @code{version} and @code{source},
7070 which it overrides. Note that the original @code{hello} variable is
7071 still there, in the @code{(gnu packages base)} module, unchanged. When
7072 you define a custom package like this, you are really @emph{adding} a
7073 new package definition; the original one remains available.
7075 You can just as well define variants with a different set of
7076 dependencies than the original package. For example, the default
7077 @code{gdb} package depends on @code{guile}, but since that is an
7078 optional dependency, you can define a variant that removes that
7082 (use-modules (gnu packages gdb) ;for 'gdb'
7083 (srfi srfi-1)) ;for 'alist-delete'
7085 (define gdb-sans-guile
7088 (inputs (alist-delete "guile"
7089 (package-inputs gdb)))))
7092 The @code{alist-delete} call above removes the tuple from the
7093 @code{inputs} field that has @code{"guile"} as its first element
7094 (@pxref{SRFI-1 Association Lists,,, guile, GNU Guile Reference
7097 In some cases, you may find it useful to write functions
7098 (``procedures'', in Scheme parlance) that return a package based on some
7099 parameters. For example, consider the @code{luasocket} library for the
7100 Lua programming language. We want to create @code{luasocket} packages
7101 for major versions of Lua. One way to do that is to define a procedure
7102 that takes a Lua package and returns a @code{luasocket} package that
7106 (define (make-lua-socket name lua)
7107 ;; Return a luasocket package built with LUA.
7111 ;; several fields omitted
7114 (synopsis "Socket library for Lua")))
7116 (define-public lua5.1-socket
7117 (make-lua-socket "lua5.1-socket" lua-5.1))
7119 (define-public lua5.2-socket
7120 (make-lua-socket "lua5.2-socket" lua-5.2))
7123 Here we have defined packages @code{lua5.1-socket} and
7124 @code{lua5.2-socket} by calling @code{make-lua-socket} with different
7125 arguments. @xref{Procedures,,, guile, GNU Guile Reference Manual}, for
7126 more info on procedures. Having top-level public definitions for these
7127 two packages means that they can be referred to from the command line
7128 (@pxref{Package Modules}).
7130 @cindex package transformations
7131 These are pretty simple package variants. As a convenience, the
7132 @code{(guix transformations)} module provides a high-level interface
7133 that directly maps to the more sophisticated package transformation
7134 options (@pxref{Package Transformation Options}):
7136 @deffn {Scheme Procedure} options->transformation @var{opts}
7137 Return a procedure that, when passed an object to build (package,
7138 derivation, etc.), applies the transformations specified by @var{opts} and returns
7139 the resulting objects. @var{opts} must be a list of symbol/string pairs such as:
7142 ((with-branch . "guile-gcrypt=master")
7143 (without-tests . "libgcrypt"))
7146 Each symbol names a transformation and the corresponding string is an argument
7147 to that transformation.
7150 For instance, a manifest equivalent to this command:
7154 --with-branch=guile-gcrypt=master \
7155 --with-debug-info=zlib
7159 ... would look like this:
7162 (use-modules (guix transformations))
7165 ;; The package transformation procedure.
7166 (options->transformation
7167 '((with-branch . "guile-gcrypt=master")
7168 (with-debug-info . "zlib"))))
7171 (list (transform (specification->package "guix"))))
7174 @cindex input rewriting
7175 @cindex dependency graph rewriting
7176 The @code{options->transformation} procedure is convenient, but it's
7177 perhaps also not as flexible as you may like. How is it implemented?
7178 The astute reader probably noticed that most package transformation
7179 options go beyond the superficial changes shown in the first examples of
7180 this section: they involve @dfn{input rewriting}, whereby the dependency
7181 graph of a package is rewritten by replacing specific inputs by others.
7183 Dependency graph rewriting, for the purposes of swapping packages in the
7184 graph, is what the @code{package-input-rewriting} procedure in
7185 @code{(guix packages)} implements.
7187 @deffn {Scheme Procedure} package-input-rewriting @var{replacements} @
7188 [@var{rewrite-name}] [#:deep? #t]
7189 Return a procedure that, when passed a package, replaces its direct and
7190 indirect dependencies, including implicit inputs when @var{deep?} is
7191 true, according to @var{replacements}. @var{replacements} is a list of
7192 package pairs; the first element of each pair is the package to replace,
7193 and the second one is the replacement.
7195 Optionally, @var{rewrite-name} is a one-argument procedure that takes
7196 the name of a package and returns its new name after rewrite.
7200 Consider this example:
7203 (define libressl-instead-of-openssl
7204 ;; This is a procedure to replace OPENSSL by LIBRESSL,
7206 (package-input-rewriting `((,openssl . ,libressl))))
7208 (define git-with-libressl
7209 (libressl-instead-of-openssl git))
7213 Here we first define a rewriting procedure that replaces @var{openssl}
7214 with @var{libressl}. Then we use it to define a @dfn{variant} of the
7215 @var{git} package that uses @var{libressl} instead of @var{openssl}.
7216 This is exactly what the @option{--with-input} command-line option does
7217 (@pxref{Package Transformation Options, @option{--with-input}}).
7219 The following variant of @code{package-input-rewriting} can match packages to
7220 be replaced by name rather than by identity.
7222 @deffn {Scheme Procedure} package-input-rewriting/spec @var{replacements} [#:deep? #t]
7223 Return a procedure that, given a package, applies the given
7224 @var{replacements} to all the package graph, including implicit inputs
7225 unless @var{deep?} is false. @var{replacements} is a list of
7226 spec/procedures pair; each spec is a package specification such as
7227 @code{"gcc"} or @code{"guile@@2"}, and each procedure takes a matching
7228 package and returns a replacement for that package.
7231 The example above could be rewritten this way:
7234 (define libressl-instead-of-openssl
7235 ;; Replace all the packages called "openssl" with LibreSSL.
7236 (package-input-rewriting/spec `(("openssl" . ,(const libressl)))))
7239 The key difference here is that, this time, packages are matched by spec and
7240 not by identity. In other words, any package in the graph that is called
7241 @code{openssl} will be replaced.
7243 A more generic procedure to rewrite a package dependency graph is
7244 @code{package-mapping}: it supports arbitrary changes to nodes in the
7247 @deffn {Scheme Procedure} package-mapping @var{proc} [@var{cut?}] [#:deep? #f]
7248 Return a procedure that, given a package, applies @var{proc} to all the packages
7249 depended on and returns the resulting package. The procedure stops recursion
7250 when @var{cut?} returns true for a given package. When @var{deep?} is true, @var{proc} is
7251 applied to implicit inputs as well.
7256 @section Build Systems
7258 @cindex build system
7259 Each package definition specifies a @dfn{build system} and arguments for
7260 that build system (@pxref{Defining Packages}). This @code{build-system}
7261 field represents the build procedure of the package, as well as implicit
7262 dependencies of that build procedure.
7264 Build systems are @code{<build-system>} objects. The interface to
7265 create and manipulate them is provided by the @code{(guix build-system)}
7266 module, and actual build systems are exported by specific modules.
7268 @cindex bag (low-level package representation)
7269 Under the hood, build systems first compile package objects to
7270 @dfn{bags}. A @dfn{bag} is like a package, but with less
7271 ornamentation---in other words, a bag is a lower-level representation of
7272 a package, which includes all the inputs of that package, including some
7273 that were implicitly added by the build system. This intermediate
7274 representation is then compiled to a derivation (@pxref{Derivations}).
7275 The @code{package-with-c-toolchain} is an example of a way to change the
7276 implicit inputs that a package's build system pulls in (@pxref{package
7277 Reference, @code{package-with-c-toolchain}}).
7279 Build systems accept an optional list of @dfn{arguments}. In package
7280 definitions, these are passed @i{via} the @code{arguments} field
7281 (@pxref{Defining Packages}). They are typically keyword arguments
7282 (@pxref{Optional Arguments, keyword arguments in Guile,, guile, GNU
7283 Guile Reference Manual}). The value of these arguments is usually
7284 evaluated in the @dfn{build stratum}---i.e., by a Guile process launched
7285 by the daemon (@pxref{Derivations}).
7287 The main build system is @code{gnu-build-system}, which implements the
7288 standard build procedure for GNU and many other packages. It
7289 is provided by the @code{(guix build-system gnu)} module.
7291 @defvr {Scheme Variable} gnu-build-system
7292 @code{gnu-build-system} represents the GNU Build System, and variants
7293 thereof (@pxref{Configuration, configuration and makefile conventions,,
7294 standards, GNU Coding Standards}).
7296 @cindex build phases
7297 In a nutshell, packages using it are configured, built, and installed with
7298 the usual @code{./configure && make && make check && make install}
7299 command sequence. In practice, a few additional steps are often needed.
7300 All these steps are split up in separate @dfn{phases},
7301 notably@footnote{Please see the @code{(guix build gnu-build-system)}
7302 modules for more details about the build phases.}:
7306 Unpack the source tarball, and change the current directory to the
7307 extracted source tree. If the source is actually a directory, copy it
7308 to the build tree, and enter that directory.
7310 @item patch-source-shebangs
7311 Patch shebangs encountered in source files so they refer to the right
7312 store file names. For instance, this changes @code{#!/bin/sh} to
7313 @code{#!/gnu/store/@dots{}-bash-4.3/bin/sh}.
7316 Run the @file{configure} script with a number of default options, such
7317 as @option{--prefix=/gnu/store/@dots{}}, as well as the options specified
7318 by the @code{#:configure-flags} argument.
7321 Run @code{make} with the list of flags specified with
7322 @code{#:make-flags}. If the @code{#:parallel-build?} argument is true
7323 (the default), build with @code{make -j}.
7326 Run @code{make check}, or some other target specified with
7327 @code{#:test-target}, unless @code{#:tests? #f} is passed. If the
7328 @code{#:parallel-tests?} argument is true (the default), run @code{make
7332 Run @code{make install} with the flags listed in @code{#:make-flags}.
7334 @item patch-shebangs
7335 Patch shebangs on the installed executable files.
7338 Strip debugging symbols from ELF files (unless @code{#:strip-binaries?}
7339 is false), copying them to the @code{debug} output when available
7340 (@pxref{Installing Debugging Files}).
7343 @vindex %standard-phases
7344 The build-side module @code{(guix build gnu-build-system)} defines
7345 @code{%standard-phases} as the default list of build phases.
7346 @code{%standard-phases} is a list of symbol/procedure pairs, where the
7347 procedure implements the actual phase.
7349 @xref{Build Phases}, for more info on build phases and ways to customize
7352 In addition, this build system ensures that the ``standard'' environment
7353 for GNU packages is available. This includes tools such as GCC, libc,
7354 Coreutils, Bash, Make, Diffutils, grep, and sed (see the @code{(guix
7355 build-system gnu)} module for a complete list). We call these the
7356 @dfn{implicit inputs} of a package, because package definitions do not
7357 have to mention them.
7360 Other @code{<build-system>} objects are defined to support other
7361 conventions and tools used by free software packages. They inherit most
7362 of @code{gnu-build-system}, and differ mainly in the set of inputs
7363 implicitly added to the build process, and in the list of phases
7364 executed. Some of these build systems are listed below.
7366 @defvr {Scheme Variable} ant-build-system
7367 This variable is exported by @code{(guix build-system ant)}. It
7368 implements the build procedure for Java packages that can be built with
7369 @url{https://ant.apache.org/, Ant build tool}.
7371 It adds both @code{ant} and the @dfn{Java Development Kit} (JDK) as
7372 provided by the @code{icedtea} package to the set of inputs. Different
7373 packages can be specified with the @code{#:ant} and @code{#:jdk}
7374 parameters, respectively.
7376 When the original package does not provide a suitable Ant build file,
7377 the parameter @code{#:jar-name} can be used to generate a minimal Ant
7378 build file @file{build.xml} with tasks to build the specified jar
7379 archive. In this case the parameter @code{#:source-dir} can be used to
7380 specify the source sub-directory, defaulting to ``src''.
7382 The @code{#:main-class} parameter can be used with the minimal ant
7383 buildfile to specify the main class of the resulting jar. This makes the
7384 jar file executable. The @code{#:test-include} parameter can be used to
7385 specify the list of junit tests to run. It defaults to
7386 @code{(list "**/*Test.java")}. The @code{#:test-exclude} can be used to
7387 disable some tests. It defaults to @code{(list "**/Abstract*.java")},
7388 because abstract classes cannot be run as tests.
7390 The parameter @code{#:build-target} can be used to specify the Ant task
7391 that should be run during the @code{build} phase. By default the
7392 ``jar'' task will be run.
7396 @defvr {Scheme Variable} android-ndk-build-system
7397 @cindex Android distribution
7398 @cindex Android NDK build system
7399 This variable is exported by @code{(guix build-system android-ndk)}. It
7400 implements a build procedure for Android NDK (native development kit)
7401 packages using a Guix-specific build process.
7403 The build system assumes that packages install their public interface
7404 (header) files to the subdirectory @file{include} of the @code{out} output and
7405 their libraries to the subdirectory @file{lib} the @code{out} output.
7407 It's also assumed that the union of all the dependencies of a package
7408 has no conflicting files.
7410 For the time being, cross-compilation is not supported - so right now
7411 the libraries and header files are assumed to be host tools.
7415 @defvr {Scheme Variable} asdf-build-system/source
7416 @defvrx {Scheme Variable} asdf-build-system/sbcl
7417 @defvrx {Scheme Variable} asdf-build-system/ecl
7419 These variables, exported by @code{(guix build-system asdf)}, implement
7420 build procedures for Common Lisp packages using
7421 @url{https://common-lisp.net/project/asdf/, ``ASDF''}. ASDF is a system
7422 definition facility for Common Lisp programs and libraries.
7424 The @code{asdf-build-system/source} system installs the packages in
7425 source form, and can be loaded using any common lisp implementation, via
7426 ASDF@. The others, such as @code{asdf-build-system/sbcl}, install binary
7427 systems in the format which a particular implementation understands.
7428 These build systems can also be used to produce executable programs, or
7429 lisp images which contain a set of packages pre-loaded.
7431 The build system uses naming conventions. For binary packages, the
7432 package name should be prefixed with the lisp implementation, such as
7433 @code{sbcl-} for @code{asdf-build-system/sbcl}.
7435 Additionally, the corresponding source package should be labeled using
7436 the same convention as python packages (see @ref{Python Modules}), using
7437 the @code{cl-} prefix.
7439 In order to create executable programs and images, the build-side
7440 procedures @code{build-program} and @code{build-image} can be used.
7441 They should be called in a build phase after the
7442 @code{create-asdf-configuration} phase, so that the system which was
7443 just built can be used within the resulting image. @code{build-program}
7444 requires a list of Common Lisp expressions to be passed as the
7445 @code{#:entry-program} argument.
7447 By default, all the @file{.asd} files present in the sources are read to
7448 find system definitions. The @code{#:asd-files} parameter can be used
7449 to specify the list of @file{.asd} files to read. Furthermore, if the
7450 package defines a system for its tests in a separate file, it will be
7451 loaded before the tests are run if it is specified by the
7452 @code{#:test-asd-file} parameter. If it is not set, the files
7453 @code{<system>-tests.asd}, @code{<system>-test.asd}, @code{tests.asd},
7454 and @code{test.asd} will be tried if they exist.
7456 If for some reason the package must be named in a different way than the
7457 naming conventions suggest, or if several systems must be compiled, the
7458 @code{#:asd-systems} parameter can be used to specify the list of system
7463 @defvr {Scheme Variable} cargo-build-system
7464 @cindex Rust programming language
7465 @cindex Cargo (Rust build system)
7466 This variable is exported by @code{(guix build-system cargo)}. It
7467 supports builds of packages using Cargo, the build tool of the
7468 @uref{https://www.rust-lang.org, Rust programming language}.
7470 It adds @code{rustc} and @code{cargo} to the set of inputs.
7471 A different Rust package can be specified with the @code{#:rust} parameter.
7473 Regular cargo dependencies should be added to the package definition similarly
7474 to other packages; those needed only at build time to native-inputs, others to
7475 inputs. If you need to add source-only crates then you should add them to via
7476 the @code{#:cargo-inputs} parameter as a list of name and spec pairs, where the
7477 spec can be a package or a source definition. Note that the spec must
7478 evaluate to a path to a gzipped tarball which includes a @code{Cargo.toml}
7479 file at its root, or it will be ignored. Similarly, cargo dev-dependencies
7480 should be added to the package definition via the
7481 @code{#:cargo-development-inputs} parameter.
7483 In its @code{configure} phase, this build system will make any source inputs
7484 specified in the @code{#:cargo-inputs} and @code{#:cargo-development-inputs}
7485 parameters available to cargo. It will also remove an included
7486 @code{Cargo.lock} file to be recreated by @code{cargo} during the
7487 @code{build} phase. The @code{package} phase will run @code{cargo package}
7488 to create a source crate for future use. The @code{install} phase installs
7489 the binaries defined by the crate. Unless @code{install-source? #f} is
7490 defined it will also install a source crate repository of itself and unpacked
7491 sources, to ease in future hacking on rust packages.
7494 @defvr {Scheme Variable} chicken-build-system
7495 This variable is exported by @code{(guix build-system chicken)}. It
7496 builds @uref{https://call-cc.org/, CHICKEN Scheme} modules, also called
7497 ``eggs'' or ``extensions''. CHICKEN generates C source code, which then
7498 gets compiled by a C compiler, in this case GCC.
7500 This build system adds @code{chicken} to the package inputs, as well as
7501 the packages of @code{gnu-build-system}.
7503 The build system can't (yet) deduce the egg's name automatically, so just like
7504 with @code{go-build-system} and its @code{#:import-path}, you should define
7505 @code{#:egg-name} in the package's @code{arguments} field.
7507 For example, if you are packaging the @code{srfi-1} egg:
7510 (arguments '(#:egg-name "srfi-1"))
7513 Egg dependencies must be defined in @code{propagated-inputs}, not @code{inputs}
7514 because CHICKEN doesn't embed absolute references in compiled eggs.
7515 Test dependencies should go to @code{native-inputs}, as usual.
7518 @defvr {Scheme Variable} copy-build-system
7519 This variable is exported by @code{(guix build-system copy)}. It
7520 supports builds of simple packages that don't require much compiling,
7521 mostly just moving files around.
7523 It adds much of the @code{gnu-build-system} packages to the set of
7524 inputs. Because of this, the @code{copy-build-system} does not require
7525 all the boilerplate code often needed for the
7526 @code{trivial-build-system}.
7528 To further simplify the file installation process, an
7529 @code{#:install-plan} argument is exposed to let the packager specify
7530 which files go where. The install plan is a list of @code{(@var{source}
7531 @var{target} [@var{filters}])}. @var{filters} are optional.
7534 @item When @var{source} matches a file or directory without trailing slash, install it to @var{target}.
7536 @item If @var{target} has a trailing slash, install @var{source} basename beneath @var{target}.
7537 @item Otherwise install @var{source} as @var{target}.
7540 @item When @var{source} is a directory with a trailing slash, or when @var{filters} are used,
7541 the trailing slash of @var{target} is implied with the same meaning
7544 @item Without @var{filters}, install the full @var{source} @emph{content} to @var{target}.
7545 @item With @var{filters} among @code{#:include}, @code{#:include-regexp}, @code{#:exclude},
7546 @code{#:exclude-regexp}, only select files are installed depending on
7547 the filters. Each filters is specified by a list of strings.
7549 @item With @code{#:include}, install all the files which the path suffix matches
7550 at least one of the elements in the given list.
7551 @item With @code{#:include-regexp}, install all the files which the
7552 subpaths match at least one of the regular expressions in the given
7554 @item The @code{#:exclude} and @code{#:exclude-regexp} filters
7555 are the complement of their inclusion counterpart. Without @code{#:include} flags,
7556 install all files but those matching the exclusion filters.
7557 If both inclusions and exclusions are specified, the exclusions are done
7558 on top of the inclusions.
7561 In all cases, the paths relative to @var{source} are preserved within
7568 @item @code{("foo/bar" "share/my-app/")}: Install @file{bar} to @file{share/my-app/bar}.
7569 @item @code{("foo/bar" "share/my-app/baz")}: Install @file{bar} to @file{share/my-app/baz}.
7570 @item @code{("foo/" "share/my-app")}: Install the content of @file{foo} inside @file{share/my-app},
7571 e.g., install @file{foo/sub/file} to @file{share/my-app/sub/file}.
7572 @item @code{("foo/" "share/my-app" #:include ("sub/file"))}: Install only @file{foo/sub/file} to
7573 @file{share/my-app/sub/file}.
7574 @item @code{("foo/sub" "share/my-app" #:include ("file"))}: Install @file{foo/sub/file} to
7575 @file{share/my-app/file}.
7580 @cindex Clojure (programming language)
7581 @cindex simple Clojure build system
7582 @defvr {Scheme Variable} clojure-build-system
7583 This variable is exported by @code{(guix build-system clojure)}. It implements
7584 a simple build procedure for @uref{https://clojure.org/, Clojure} packages
7585 using plain old @code{compile} in Clojure. Cross-compilation is not supported
7588 It adds @code{clojure}, @code{icedtea} and @code{zip} to the set of inputs.
7589 Different packages can be specified with the @code{#:clojure}, @code{#:jdk} and
7590 @code{#:zip} parameters, respectively.
7592 A list of source directories, test directories and jar names can be specified
7593 with the @code{#:source-dirs}, @code{#:test-dirs} and @code{#:jar-names}
7594 parameters, respectively. Compile directory and main class can be specified
7595 with the @code{#:compile-dir} and @code{#:main-class} parameters, respectively.
7596 Other parameters are documented below.
7598 This build system is an extension of @code{ant-build-system}, but with the
7599 following phases changed:
7604 This phase calls @code{compile} in Clojure to compile source files and runs
7605 @command{jar} to create jars from both source files and compiled files
7606 according to the include list and exclude list specified in
7607 @code{#:aot-include} and @code{#:aot-exclude}, respectively. The exclude list
7608 has priority over the include list. These lists consist of symbols
7609 representing Clojure libraries or the special keyword @code{#:all} representing
7610 all Clojure libraries found under the source directories. The parameter
7611 @code{#:omit-source?} decides if source should be included into the jars.
7614 This phase runs tests according to the include list and exclude list specified
7615 in @code{#:test-include} and @code{#:test-exclude}, respectively. Their
7616 meanings are analogous to that of @code{#:aot-include} and
7617 @code{#:aot-exclude}, except that the special keyword @code{#:all} now
7618 stands for all Clojure libraries found under the test directories. The
7619 parameter @code{#:tests?} decides if tests should be run.
7622 This phase installs all jars built previously.
7625 Apart from the above, this build system also contains an additional phase:
7630 This phase installs all top-level files with base name matching
7631 @code{%doc-regex}. A different regex can be specified with the
7632 @code{#:doc-regex} parameter. All files (recursively) inside the documentation
7633 directories specified in @code{#:doc-dirs} are installed as well.
7637 @defvr {Scheme Variable} cmake-build-system
7638 This variable is exported by @code{(guix build-system cmake)}. It
7639 implements the build procedure for packages using the
7640 @url{https://www.cmake.org, CMake build tool}.
7642 It automatically adds the @code{cmake} package to the set of inputs.
7643 Which package is used can be specified with the @code{#:cmake}
7646 The @code{#:configure-flags} parameter is taken as a list of flags
7647 passed to the @command{cmake} command. The @code{#:build-type}
7648 parameter specifies in abstract terms the flags passed to the compiler;
7649 it defaults to @code{"RelWithDebInfo"} (short for ``release mode with
7650 debugging information''), which roughly means that code is compiled with
7651 @code{-O2 -g}, as is the case for Autoconf-based packages by default.
7654 @defvr {Scheme Variable} dune-build-system
7655 This variable is exported by @code{(guix build-system dune)}. It
7656 supports builds of packages using @uref{https://dune.build/, Dune}, a build
7657 tool for the OCaml programming language. It is implemented as an extension
7658 of the @code{ocaml-build-system} which is described below. As such, the
7659 @code{#:ocaml} and @code{#:findlib} parameters can be passed to this build
7662 It automatically adds the @code{dune} package to the set of inputs.
7663 Which package is used can be specified with the @code{#:dune}
7666 There is no @code{configure} phase because dune packages typically don't
7667 need to be configured. The @code{#:build-flags} parameter is taken as a
7668 list of flags passed to the @code{dune} command during the build.
7670 The @code{#:jbuild?} parameter can be passed to use the @code{jbuild}
7671 command instead of the more recent @code{dune} command while building
7672 a package. Its default value is @code{#f}.
7674 The @code{#:package} parameter can be passed to specify a package name, which
7675 is useful when a package contains multiple packages and you want to build
7676 only one of them. This is equivalent to passing the @code{-p} argument to
7680 @defvr {Scheme Variable} go-build-system
7681 This variable is exported by @code{(guix build-system go)}. It
7682 implements a build procedure for Go packages using the standard
7683 @url{https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies,
7684 Go build mechanisms}.
7686 The user is expected to provide a value for the key @code{#:import-path}
7687 and, in some cases, @code{#:unpack-path}. The
7688 @url{https://golang.org/doc/code.html#ImportPaths, import path}
7689 corresponds to the file system path expected by the package's build
7690 scripts and any referring packages, and provides a unique way to
7691 refer to a Go package. It is typically based on a combination of the
7692 package source code's remote URI and file system hierarchy structure. In
7693 some cases, you will need to unpack the package's source code to a
7694 different directory structure than the one indicated by the import path,
7695 and @code{#:unpack-path} should be used in such cases.
7697 Packages that provide Go libraries should install their source code into
7698 the built output. The key @code{#:install-source?}, which defaults to
7699 @code{#t}, controls whether or not the source code is installed. It can
7700 be set to @code{#f} for packages that only provide executable files.
7703 @defvr {Scheme Variable} glib-or-gtk-build-system
7704 This variable is exported by @code{(guix build-system glib-or-gtk)}. It
7705 is intended for use with packages making use of GLib or GTK+.
7707 This build system adds the following two phases to the ones defined by
7708 @code{gnu-build-system}:
7711 @item glib-or-gtk-wrap
7712 The phase @code{glib-or-gtk-wrap} ensures that programs in
7713 @file{bin/} are able to find GLib ``schemas'' and
7714 @uref{https://developer.gnome.org/gtk3/stable/gtk-running.html, GTK+
7715 modules}. This is achieved by wrapping the programs in launch scripts
7716 that appropriately set the @env{XDG_DATA_DIRS} and @env{GTK_PATH}
7717 environment variables.
7719 It is possible to exclude specific package outputs from that wrapping
7720 process by listing their names in the
7721 @code{#:glib-or-gtk-wrap-excluded-outputs} parameter. This is useful
7722 when an output is known not to contain any GLib or GTK+ binaries, and
7723 where wrapping would gratuitously add a dependency of that output on
7726 @item glib-or-gtk-compile-schemas
7727 The phase @code{glib-or-gtk-compile-schemas} makes sure that all
7728 @uref{https://developer.gnome.org/gio/stable/glib-compile-schemas.html,
7729 GSettings schemas} of GLib are compiled. Compilation is performed by the
7730 @command{glib-compile-schemas} program. It is provided by the package
7731 @code{glib:bin} which is automatically imported by the build system.
7732 The @code{glib} package providing @command{glib-compile-schemas} can be
7733 specified with the @code{#:glib} parameter.
7736 Both phases are executed after the @code{install} phase.
7739 @defvr {Scheme Variable} guile-build-system
7740 This build system is for Guile packages that consist exclusively of Scheme
7741 code and that are so lean that they don't even have a makefile, let alone a
7742 @file{configure} script. It compiles Scheme code using @command{guild
7743 compile} (@pxref{Compilation,,, guile, GNU Guile Reference Manual}) and
7744 installs the @file{.scm} and @file{.go} files in the right place. It also
7745 installs documentation.
7747 This build system supports cross-compilation by using the
7748 @option{--target} option of @samp{guild compile}.
7750 Packages built with @code{guile-build-system} must provide a Guile package in
7751 their @code{native-inputs} field.
7754 @defvr {Scheme Variable} julia-build-system
7755 This variable is exported by @code{(guix build-system julia)}. It
7756 implements the build procedure used by @uref{https://julialang.org/,
7757 julia} packages, which essentially is similar to running @samp{julia -e
7758 'using Pkg; Pkg.add(package)'} in an environment where
7759 @env{JULIA_LOAD_PATH} contains the paths to all Julia package inputs.
7760 Tests are run by calling @code{/test/runtests.jl}.
7762 The Julia package name is read from the file @file{Project.toml}. This
7763 value can be overridden by passing the argument @code{#:julia-package-name}
7764 (which must be correctly capitalized).
7766 Julia packages usually manage their binary dependencies via
7767 @code{JLLWrappers.jl}, a Julia package that creates a module (named
7768 after the wrapped library followed by @code{_jll.jl}.
7770 To add the binary path @code{_jll.jl} packages, you need to patch the
7771 files under @file{src/wrappers/}, replacing the call to the macro
7772 @code{JLLWrappers.@@generate_wrapper_header}, adding as a secound
7773 argument containing the store path the binary.
7775 As an example, in the MbedTLS Julia package, we add a build phase
7776 (@pxref{Build Phases}) to insert the absolute file name of the wrapped
7780 (add-after 'unpack 'override-binary-path
7781 (lambda* (#:key inputs #:allow-other-keys)
7782 (for-each (lambda (wrapper)
7783 (substitute* wrapper
7784 (("generate_wrapper_header.*")
7786 "generate_wrapper_header(\"MbedTLS\", \""
7787 (assoc-ref inputs "mbedtls-apache") "\")\n"))))
7788 ;; There's a Julia file for each platform, override them all.
7789 (find-files "src/wrappers/" "\\.jl$"))))
7792 Some older packages that aren't using @file{Package.toml} yet, will require
7793 this file to be created, too. The function @code{julia-create-package-toml}
7794 helps creating the file. You need to pass the outputs and the source of the
7795 package, it's name (the same as the @code{file-name} parameter), the package
7796 uuid, the package version, and a list of dependencies specified by their name
7800 @defvr {Scheme Variable} maven-build-system
7801 This variable is exported by @code{(guix build-system maven)}. It implements
7802 a build procedure for @uref{https://maven.apache.org, Maven} packages. Maven
7803 is a dependency and lifecycle management tool for Java. A user of Maven
7804 specifies dependencies and plugins in a @file{pom.xml} file that Maven reads.
7805 When Maven does not have one of the dependencies or plugins in its repository,
7806 it will download them and use them to build the package.
7808 The maven build system ensures that maven will not try to download any
7809 dependency by running in offline mode. Maven will fail if a dependency is
7810 missing. Before running Maven, the @file{pom.xml} (and subprojects) are
7811 modified to specify the version of dependencies and plugins that match the
7812 versions available in the guix build environment. Dependencies and plugins
7813 must be installed in the fake maven repository at @file{lib/m2}, and are
7814 symlinked into a proper repository before maven is run. Maven is instructed
7815 to use that repository for the build and installs built artifacts there.
7816 Changed files are copied to the @file{lib/m2} directory of the package output.
7818 You can specify a @file{pom.xml} file with the @code{#:pom-file} argument,
7819 or let the build system use the default @file{pom.xml} file in the sources.
7821 In case you need to specify a dependency's version manually, you can use the
7822 @code{#:local-packages} argument. It takes an association list where the key
7823 is the groupId of the package and its value is an association list where the
7824 key is the artifactId of the package and its value is the version you want to
7825 override in the @file{pom.xml}.
7827 Some packages use dependencies or plugins that are not useful at runtime nor
7828 at build time in Guix. You can alter the @file{pom.xml} file to remove them
7829 using the @code{#:exclude} argument. Its value is an association list where
7830 the key is the groupId of the plugin or dependency you want to remove, and
7831 the value is a list of artifactId you want to remove.
7833 You can override the default @code{jdk} and @code{maven} packages with the
7834 corresponding argument, @code{#:jdk} and @code{#:maven}.
7836 The @code{#:maven-plugins} argument is a list of maven plugins used during
7837 the build, with the same format as the @code{inputs} fields of the package
7838 declaration. Its default value is @code{(default-maven-plugins)} which is
7842 @defvr {Scheme Variable} minify-build-system
7843 This variable is exported by @code{(guix build-system minify)}. It
7844 implements a minification procedure for simple JavaScript packages.
7846 It adds @code{uglify-js} to the set of inputs and uses it to compress
7847 all JavaScript files in the @file{src} directory. A different minifier
7848 package can be specified with the @code{#:uglify-js} parameter, but it
7849 is expected that the package writes the minified code to the standard
7852 When the input JavaScript files are not all located in the @file{src}
7853 directory, the parameter @code{#:javascript-files} can be used to
7854 specify a list of file names to feed to the minifier.
7857 @defvr {Scheme Variable} ocaml-build-system
7858 This variable is exported by @code{(guix build-system ocaml)}. It implements
7859 a build procedure for @uref{https://ocaml.org, OCaml} packages, which consists
7860 of choosing the correct set of commands to run for each package. OCaml
7861 packages can expect many different commands to be run. This build system will
7864 When the package has a @file{setup.ml} file present at the top-level, it will
7865 run @code{ocaml setup.ml -configure}, @code{ocaml setup.ml -build} and
7866 @code{ocaml setup.ml -install}. The build system will assume that this file
7867 was generated by @uref{http://oasis.forge.ocamlcore.org/, OASIS} and will take
7868 care of setting the prefix and enabling tests if they are not disabled. You
7869 can pass configure and build flags with the @code{#:configure-flags} and
7870 @code{#:build-flags}. The @code{#:test-flags} key can be passed to change the
7871 set of flags used to enable tests. The @code{#:use-make?} key can be used to
7872 bypass this system in the build and install phases.
7874 When the package has a @file{configure} file, it is assumed that it is a
7875 hand-made configure script that requires a different argument format than
7876 in the @code{gnu-build-system}. You can add more flags with the
7877 @code{#:configure-flags} key.
7879 When the package has a @file{Makefile} file (or @code{#:use-make?} is
7880 @code{#t}), it will be used and more flags can be passed to the build and
7881 install phases with the @code{#:make-flags} key.
7883 Finally, some packages do not have these files and use a somewhat standard
7884 location for its build system. In that case, the build system will run
7885 @code{ocaml pkg/pkg.ml} or @code{ocaml pkg/build.ml} and take care of
7886 providing the path to the required findlib module. Additional flags can
7887 be passed via the @code{#:build-flags} key. Install is taken care of by
7888 @command{opam-installer}. In this case, the @code{opam} package must
7889 be added to the @code{native-inputs} field of the package definition.
7891 Note that most OCaml packages assume they will be installed in the same
7892 directory as OCaml, which is not what we want in guix. In particular, they
7893 will install @file{.so} files in their module's directory, which is usually
7894 fine because it is in the OCaml compiler directory. In guix though, these
7895 libraries cannot be found and we use @env{CAML_LD_LIBRARY_PATH}. This
7896 variable points to @file{lib/ocaml/site-lib/stubslibs} and this is where
7897 @file{.so} libraries should be installed.
7900 @defvr {Scheme Variable} python-build-system
7901 This variable is exported by @code{(guix build-system python)}. It
7902 implements the more or less standard build procedure used by Python
7903 packages, which consists in running @code{python setup.py build} and
7904 then @code{python setup.py install --prefix=/gnu/store/@dots{}}.
7906 For packages that install stand-alone Python programs under @code{bin/},
7907 it takes care of wrapping these programs so that their @env{PYTHONPATH}
7908 environment variable points to all the Python libraries they depend on.
7910 Which Python package is used to perform the build can be specified with
7911 the @code{#:python} parameter. This is a useful way to force a package
7912 to be built for a specific version of the Python interpreter, which
7913 might be necessary if the package is only compatible with a single
7914 interpreter version.
7916 By default guix calls @code{setup.py} under control of
7917 @code{setuptools}, much like @command{pip} does. Some packages are not
7918 compatible with setuptools (and pip), thus you can disable this by
7919 setting the @code{#:use-setuptools?} parameter to @code{#f}.
7922 @defvr {Scheme Variable} perl-build-system
7923 This variable is exported by @code{(guix build-system perl)}. It
7924 implements the standard build procedure for Perl packages, which either
7925 consists in running @code{perl Build.PL --prefix=/gnu/store/@dots{}},
7926 followed by @code{Build} and @code{Build install}; or in running
7927 @code{perl Makefile.PL PREFIX=/gnu/store/@dots{}}, followed by
7928 @code{make} and @code{make install}, depending on which of
7929 @code{Build.PL} or @code{Makefile.PL} is present in the package
7930 distribution. Preference is given to the former if both @code{Build.PL}
7931 and @code{Makefile.PL} exist in the package distribution. This
7932 preference can be reversed by specifying @code{#t} for the
7933 @code{#:make-maker?} parameter.
7935 The initial @code{perl Makefile.PL} or @code{perl Build.PL} invocation
7936 passes flags specified by the @code{#:make-maker-flags} or
7937 @code{#:module-build-flags} parameter, respectively.
7939 Which Perl package is used can be specified with @code{#:perl}.
7942 @defvr {Scheme Variable} renpy-build-system
7943 This variable is exported by @code{(guix build-system renpy)}. It implements
7944 the more or less standard build procedure used by Ren'py games, which consists
7945 of loading @code{#:game} once, thereby creating bytecode for it.
7947 It further creates a wrapper script in @code{bin/} and a desktop entry in
7948 @code{share/applications}, both of which can be used to launch the game.
7950 Which Ren'py package is used can be specified with @code{#:renpy}.
7951 Games can also be installed in outputs other than ``out'' by using
7955 @defvr {Scheme Variable} qt-build-system
7956 This variable is exported by @code{(guix build-system qt)}. It
7957 is intended for use with applications using Qt or KDE.
7959 This build system adds the following two phases to the ones defined by
7960 @code{cmake-build-system}:
7964 The phase @code{check-setup} prepares the environment for running
7965 the checks as commonly used by Qt test programs.
7966 For now this only sets some environment variables:
7967 @code{QT_QPA_PLATFORM=offscreen},
7968 @code{DBUS_FATAL_WARNINGS=0} and
7969 @code{CTEST_OUTPUT_ON_FAILURE=1}.
7971 This phase is added before the @code{check} phase.
7972 It's a separate phase to ease adjusting if necessary.
7975 The phase @code{qt-wrap}
7976 searches for Qt5 plugin paths, QML paths and some XDG in the inputs
7977 and output. In case some path is found, all programs in the output's
7978 @file{bin/}, @file{sbin/}, @file{libexec/} and @file{lib/libexec/} directories
7979 are wrapped in scripts defining the necessary environment variables.
7981 It is possible to exclude specific package outputs from that wrapping process
7982 by listing their names in the @code{#:qt-wrap-excluded-outputs} parameter.
7983 This is useful when an output is known not to contain any Qt binaries, and
7984 where wrapping would gratuitously add a dependency of that output on Qt, KDE,
7987 This phase is added after the @code{install} phase.
7991 @defvr {Scheme Variable} r-build-system
7992 This variable is exported by @code{(guix build-system r)}. It
7993 implements the build procedure used by @uref{https://r-project.org, R}
7994 packages, which essentially is little more than running @samp{R CMD
7995 INSTALL --library=/gnu/store/@dots{}} in an environment where
7996 @env{R_LIBS_SITE} contains the paths to all R package inputs. Tests are
7997 run after installation using the R function
7998 @code{tools::testInstalledPackage}.
8001 @defvr {Scheme Variable} rakudo-build-system
8002 This variable is exported by @code{(guix build-system rakudo)}. It
8003 implements the build procedure used by @uref{https://rakudo.org/,
8004 Rakudo} for @uref{https://perl6.org/, Perl6} packages. It installs the
8005 package to @code{/gnu/store/@dots{}/NAME-VERSION/share/perl6} and
8006 installs the binaries, library files and the resources, as well as wrap
8007 the files under the @code{bin/} directory. Tests can be skipped by
8008 passing @code{#f} to the @code{tests?} parameter.
8010 Which rakudo package is used can be specified with @code{rakudo}.
8011 Which perl6-tap-harness package used for the tests can be specified with
8012 @code{#:prove6} or removed by passing @code{#f} to the
8013 @code{with-prove6?} parameter.
8014 Which perl6-zef package used for tests and installing can be specified
8015 with @code{#:zef} or removed by passing @code{#f} to the
8016 @code{with-zef?} parameter.
8019 @defvr {Scheme Variable} texlive-build-system
8020 This variable is exported by @code{(guix build-system texlive)}. It is
8021 used to build TeX packages in batch mode with a specified engine. The
8022 build system sets the @env{TEXINPUTS} variable to find all TeX source
8023 files in the inputs.
8025 By default it runs @code{luatex} on all files ending on @code{ins}. A
8026 different engine and format can be specified with the
8027 @code{#:tex-format} argument. Different build targets can be specified
8028 with the @code{#:build-targets} argument, which expects a list of file
8029 names. The build system adds only @code{texlive-bin} and
8030 @code{texlive-latex-base} (both from @code{(gnu packages tex}) to the
8031 inputs. Both can be overridden with the arguments @code{#:texlive-bin}
8032 and @code{#:texlive-latex-base}, respectively.
8034 The @code{#:tex-directory} parameter tells the build system where to
8035 install the built files under the texmf tree.
8038 @defvr {Scheme Variable} ruby-build-system
8039 This variable is exported by @code{(guix build-system ruby)}. It
8040 implements the RubyGems build procedure used by Ruby packages, which
8041 involves running @code{gem build} followed by @code{gem install}.
8043 The @code{source} field of a package that uses this build system
8044 typically references a gem archive, since this is the format that Ruby
8045 developers use when releasing their software. The build system unpacks
8046 the gem archive, potentially patches the source, runs the test suite,
8047 repackages the gem, and installs it. Additionally, directories and
8048 tarballs may be referenced to allow building unreleased gems from Git or
8049 a traditional source release tarball.
8051 Which Ruby package is used can be specified with the @code{#:ruby}
8052 parameter. A list of additional flags to be passed to the @command{gem}
8053 command can be specified with the @code{#:gem-flags} parameter.
8056 @defvr {Scheme Variable} waf-build-system
8057 This variable is exported by @code{(guix build-system waf)}. It
8058 implements a build procedure around the @code{waf} script. The common
8059 phases---@code{configure}, @code{build}, and @code{install}---are
8060 implemented by passing their names as arguments to the @code{waf}
8063 The @code{waf} script is executed by the Python interpreter. Which
8064 Python package is used to run the script can be specified with the
8065 @code{#:python} parameter.
8068 @defvr {Scheme Variable} scons-build-system
8069 This variable is exported by @code{(guix build-system scons)}. It
8070 implements the build procedure used by the SCons software construction
8071 tool. This build system runs @code{scons} to build the package,
8072 @code{scons test} to run tests, and then @code{scons install} to install
8075 Additional flags to be passed to @code{scons} can be specified with the
8076 @code{#:scons-flags} parameter. The default build and install targets
8077 can be overridden with @code{#:build-targets} and
8078 @code{#:install-targets} respectively. The version of Python used to
8079 run SCons can be specified by selecting the appropriate SCons package
8080 with the @code{#:scons} parameter.
8083 @defvr {Scheme Variable} haskell-build-system
8084 This variable is exported by @code{(guix build-system haskell)}. It
8085 implements the Cabal build procedure used by Haskell packages, which
8086 involves running @code{runhaskell Setup.hs configure
8087 --prefix=/gnu/store/@dots{}} and @code{runhaskell Setup.hs build}.
8088 Instead of installing the package by running @code{runhaskell Setup.hs
8089 install}, to avoid trying to register libraries in the read-only
8090 compiler store directory, the build system uses @code{runhaskell
8091 Setup.hs copy}, followed by @code{runhaskell Setup.hs register}. In
8092 addition, the build system generates the package documentation by
8093 running @code{runhaskell Setup.hs haddock}, unless @code{#:haddock? #f}
8094 is passed. Optional Haddock parameters can be passed with the help of
8095 the @code{#:haddock-flags} parameter. If the file @code{Setup.hs} is
8096 not found, the build system looks for @code{Setup.lhs} instead.
8098 Which Haskell compiler is used can be specified with the @code{#:haskell}
8099 parameter which defaults to @code{ghc}.
8102 @defvr {Scheme Variable} dub-build-system
8103 This variable is exported by @code{(guix build-system dub)}. It
8104 implements the Dub build procedure used by D packages, which
8105 involves running @code{dub build} and @code{dub run}.
8106 Installation is done by copying the files manually.
8108 Which D compiler is used can be specified with the @code{#:ldc}
8109 parameter which defaults to @code{ldc}.
8112 @anchor{emacs-build-system}
8113 @defvr {Scheme Variable} emacs-build-system
8114 This variable is exported by @code{(guix build-system emacs)}. It
8115 implements an installation procedure similar to the packaging system
8116 of Emacs itself (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
8118 It first creates the @code{@code{package}-autoloads.el} file, then it
8119 byte compiles all Emacs Lisp files. Differently from the Emacs
8120 packaging system, the Info documentation files are moved to the standard
8121 documentation directory and the @file{dir} file is deleted. The Elisp
8122 package files are installed directly under @file{share/emacs/site-lisp}.
8125 @defvr {Scheme Variable} font-build-system
8126 This variable is exported by @code{(guix build-system font)}. It
8127 implements an installation procedure for font packages where upstream
8128 provides pre-compiled TrueType, OpenType, etc.@: font files that merely
8129 need to be copied into place. It copies font files to standard
8130 locations in the output directory.
8133 @defvr {Scheme Variable} meson-build-system
8134 This variable is exported by @code{(guix build-system meson)}. It
8135 implements the build procedure for packages that use
8136 @url{https://mesonbuild.com, Meson} as their build system.
8138 It adds both Meson and @uref{https://ninja-build.org/, Ninja} to the set
8139 of inputs, and they can be changed with the parameters @code{#:meson}
8140 and @code{#:ninja} if needed. The default Meson is
8141 @code{meson-for-build}, which is special because it doesn't clear the
8142 @code{RUNPATH} of binaries and libraries when they are installed.
8144 This build system is an extension of @code{gnu-build-system}, but with the
8145 following phases changed to some specific for Meson:
8150 The phase runs @code{meson} with the flags specified in
8151 @code{#:configure-flags}. The flag @option{--buildtype} is always set to
8152 @code{debugoptimized} unless something else is specified in
8153 @code{#:build-type}.
8156 The phase runs @code{ninja} to build the package in parallel by default, but
8157 this can be changed with @code{#:parallel-build?}.
8160 The phase runs @code{ninja} with the target specified in @code{#:test-target},
8161 which is @code{"test"} by default.
8164 The phase runs @code{ninja install} and can not be changed.
8167 Apart from that, the build system also adds the following phases:
8172 This phase ensures that all binaries can find the libraries they need.
8173 It searches for required libraries in subdirectories of the package being
8174 built, and adds those to @code{RUNPATH} where needed. It also removes
8175 references to libraries left over from the build phase by
8176 @code{meson-for-build}, such as test dependencies, that aren't actually
8177 required for the program to run.
8179 @item glib-or-gtk-wrap
8180 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8181 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8183 @item glib-or-gtk-compile-schemas
8184 This phase is the phase provided by @code{glib-or-gtk-build-system}, and it
8185 is not enabled by default. It can be enabled with @code{#:glib-or-gtk?}.
8189 @defvr {Scheme Variable} linux-module-build-system
8190 @code{linux-module-build-system} allows building Linux kernel modules.
8192 @cindex build phases
8193 This build system is an extension of @code{gnu-build-system}, but with the
8194 following phases changed:
8199 This phase configures the environment so that the Linux kernel's Makefile
8200 can be used to build the external kernel module.
8203 This phase uses the Linux kernel's Makefile in order to build the external
8207 This phase uses the Linux kernel's Makefile in order to install the external
8211 It is possible and useful to specify the Linux kernel to use for building
8212 the module (in the @code{arguments} form of a package using the
8213 @code{linux-module-build-system}, use the key @code{#:linux} to specify it).
8216 @defvr {Scheme Variable} node-build-system
8217 This variable is exported by @code{(guix build-system node)}. It
8218 implements the build procedure used by @uref{https://nodejs.org,
8219 Node.js}, which implements an approximation of the @code{npm install}
8220 command, followed by an @code{npm test} command.
8222 Which Node.js package is used to interpret the @code{npm} commands can
8223 be specified with the @code{#:node} parameter which defaults to
8227 Lastly, for packages that do not need anything as sophisticated, a
8228 ``trivial'' build system is provided. It is trivial in the sense that
8229 it provides basically no support: it does not pull any implicit inputs,
8230 and does not have a notion of build phases.
8232 @defvr {Scheme Variable} trivial-build-system
8233 This variable is exported by @code{(guix build-system trivial)}.
8235 This build system requires a @code{#:builder} argument. This argument
8236 must be a Scheme expression that builds the package output(s)---as
8237 with @code{build-expression->derivation} (@pxref{Derivations,
8238 @code{build-expression->derivation}}).
8242 @section Build Phases
8244 @cindex build phases, for packages
8245 Almost all package build systems implement a notion @dfn{build phases}:
8246 a sequence of actions that the build system executes, when you build the
8247 package, leading to the installed byproducts in the store. A notable
8248 exception is the ``bare-bones'' @code{trivial-build-system}
8249 (@pxref{Build Systems}).
8251 As discussed in the previous section, those build systems provide a
8252 standard list of phases. For @code{gnu-build-system}, the standard
8253 phases include an @code{unpack} phase to unpack the source code tarball,
8254 a @command{configure} phase to run @code{./configure}, a @code{build}
8255 phase to run @command{make}, and (among others) an @code{install} phase
8256 to run @command{make install}; @pxref{Build Systems}, for a more
8257 detailed view of these phases. Likewise, @code{cmake-build-system}
8258 inherits these phases, but its @code{configure} phase runs
8259 @command{cmake} instead of @command{./configure}. Other build systems,
8260 such as @code{python-build-system}, have a wholly different list of
8261 standard phases. All this code runs on the @dfn{build side}: it is
8262 evaluated when you actually build the package, in a dedicated build
8263 process spawned by the build daemon (@pxref{Invoking guix-daemon}).
8265 Build phases are represented as association lists or ``alists''
8266 (@pxref{Association Lists,,, guile, GNU Guile Reference Manual}) where
8267 each key is a symbol for the name of the phase and the associated value
8268 is a procedure that accepts an arbitrary number of arguments. By
8269 convention, those procedures receive information about the build in the
8270 form of @dfn{keyword parameters}, which they can use or ignore.
8272 For example, here is how @code{(guix build gnu-build-system)} defines
8273 @code{%standard-phases}, the variable holding its alist of build
8274 phases@footnote{We present a simplified view of those build phases, but
8275 do take a look at @code{(guix build gnu-build-system)} to see all the
8279 ;; The build phases of 'gnu-build-system'.
8281 (define* (unpack #:key source #:allow-other-keys)
8282 ;; Extract the source tarball.
8283 (invoke "tar" "xvf" source))
8285 (define* (configure #:key outputs #:allow-other-keys)
8286 ;; Run the 'configure' script. Install to output "out".
8287 (let ((out (assoc-ref outputs "out")))
8288 (invoke "./configure"
8289 (string-append "--prefix=" out))))
8291 (define* (build #:allow-other-keys)
8295 (define* (check #:key (test-target "check") (tests? #true)
8297 ;; Run the test suite.
8299 (invoke "make" test-target)
8300 (display "test suite not run\n")))
8302 (define* (install #:allow-other-keys)
8303 ;; Install files to the prefix 'configure' specified.
8304 (invoke "make" "install"))
8306 (define %standard-phases
8307 ;; The list of standard phases (quite a few are omitted
8308 ;; for brevity). Each element is a symbol/procedure pair.
8309 (list (cons 'unpack unpack)
8310 (cons 'configure configure)
8313 (cons 'install install)))
8316 This shows how @code{%standard-phases} is defined as a list of
8317 symbol/procedure pairs (@pxref{Pairs,,, guile, GNU Guile Reference
8318 Manual}). The first pair associates the @code{unpack} procedure with
8319 the @code{unpack} symbol---a name; the second pair defines the
8320 @code{configure} phase similarly, and so on. When building a package
8321 that uses @code{gnu-build-system} with its default list of phases, those
8322 phases are executed sequentially. You can see the name of each phase
8323 started and completed in the build log of packages that you build.
8325 Let's now look at the procedures themselves. Each one is defined with
8326 @code{define*}: @code{#:key} lists keyword parameters the procedure
8327 accepts, possibly with a default value, and @code{#:allow-other-keys}
8328 specifies that other keyword parameters are ignored (@pxref{Optional
8329 Arguments,,, guile, GNU Guile Reference Manual}).
8331 The @code{unpack} procedure honors the @code{source} parameter, which
8332 the build system uses to pass the file name of the source tarball (or
8333 version control checkout), and it ignores other parameters. The
8334 @code{configure} phase only cares about the @code{outputs} parameter, an
8335 alist mapping package output names to their store file name
8336 (@pxref{Packages with Multiple Outputs}). It extracts the file name of
8337 for @code{out}, the default output, and passes it to
8338 @command{./configure} as the installation prefix, meaning that
8339 @command{make install} will eventually copy all the files in that
8340 directory (@pxref{Configuration, configuration and makefile
8341 conventions,, standards, GNU Coding Standards}). @code{build} and
8342 @code{install} ignore all their arguments. @code{check} honors the
8343 @code{test-target} argument, which specifies the name of the Makefile
8344 target to run tests; it prints a message and skips tests when
8345 @code{tests?} is false.
8347 @cindex build phases, customizing
8348 The list of phases used for a particular package can be changed with the
8349 @code{#:phases} parameter of the build system. Changing the set of
8350 build phases boils down to building a new alist of phases based on the
8351 @code{%standard-phases} alist described above. This can be done with
8352 standard alist procedures such as @code{alist-delete} (@pxref{SRFI-1
8353 Association Lists,,, guile, GNU Guile Reference Manual}); however, it is
8354 more convenient to do so with @code{modify-phases} (@pxref{Build
8355 Utilities, @code{modify-phases}}).
8357 Here is an example of a package definition that removes the
8358 @code{configure} phase of @code{%standard-phases} and inserts a new
8359 phase before the @code{build} phase, called
8360 @code{set-prefix-in-makefile}:
8363 (define-public example
8366 ;; other fields omitted
8367 (build-system gnu-build-system)
8369 '(#:phases (modify-phases %standard-phases
8371 (add-before 'build 'set-prefix-in-makefile
8372 (lambda* (#:key outputs #:allow-other-keys)
8373 ;; Modify the makefile so that its
8374 ;; 'PREFIX' variable points to "out".
8375 (let ((out (assoc-ref outputs "out")))
8376 (substitute* "Makefile"
8378 (string-append "PREFIX = "
8383 The new phase that is inserted is written as an anonymous procedure,
8384 introduced with @code{lambda*}; it honors the @code{outputs} parameter
8385 we have seen before. @xref{Build Utilities}, for more about the helpers
8386 used by this phase, and for more examples of @code{modify-phases}.
8388 @cindex code staging
8389 @cindex staging, of code
8390 Keep in mind that build phases are code evaluated at the time the
8391 package is actually built. This explains why the whole
8392 @code{modify-phases} expression above is quoted (it comes after the
8393 @code{'} or apostrophe): it is @dfn{staged} for later execution.
8394 @xref{G-Expressions}, for an explanation of code staging and the
8395 @dfn{code strata} involved.
8397 @node Build Utilities
8398 @section Build Utilities
8400 As soon as you start writing non-trivial package definitions
8401 (@pxref{Defining Packages}) or other build actions
8402 (@pxref{G-Expressions}), you will likely start looking for helpers for
8403 ``shell-like'' actions---creating directories, copying and deleting
8404 files recursively, manipulating build phases, and so on. The
8405 @code{(guix build utils)} module provides such utility procedures.
8407 Most build systems load @code{(guix build utils)} (@pxref{Build
8408 Systems}). Thus, when writing custom build phases for your package
8409 definitions, you can usually assume those procedures are in scope.
8411 When writing G-expressions, you can import @code{(guix build utils)} on
8412 the ``build side'' using @code{with-imported-modules} and then put it in
8413 scope with the @code{use-modules} form (@pxref{Using Guile Modules,,,
8414 guile, GNU Guile Reference Manual}):
8417 (with-imported-modules '((guix build utils)) ;import it
8418 (computed-file "empty-tree"
8421 (use-modules (guix build utils))
8423 ;; Happily use its 'mkdir-p' procedure.
8424 (mkdir-p (string-append #$output "/a/b/c")))))
8427 The remainder of this section is the reference for most of the utility
8428 procedures provided by @code{(guix build utils)}.
8430 @c TODO Document what's missing.
8432 @subsection Dealing with Store File Names
8434 This section documents procedures that deal with store file names.
8436 @deffn {Scheme Procedure} %store-directory
8437 Return the directory name of the store.
8440 @deffn {Scheme Procedure} store-file-name? @var{file}
8441 Return true if @var{file} is in the store.
8444 @deffn {Scheme Procedure} strip-store-file-name @var{file}
8445 Strip the @file{/gnu/store} and hash from @var{file}, a store file name.
8446 The result is typically a @code{"@var{package}-@var{version}"} string.
8449 @deffn {Scheme Procedure} package-name->name+version @var{name}
8450 Given @var{name}, a package name like @code{"foo-0.9.1b"}, return two
8451 values: @code{"foo"} and @code{"0.9.1b"}. When the version part is
8452 unavailable, @var{name} and @code{#f} are returned. The first hyphen
8453 followed by a digit is considered to introduce the version part.
8456 @subsection File Types
8458 The procedures below deal with files and file types.
8460 @deffn {Scheme Procedure} directory-exists? @var{dir}
8461 Return @code{#t} if @var{dir} exists and is a directory.
8464 @deffn {Scheme Procedure} executable-file? @var{file}
8465 Return @code{#t} if @var{file} exists and is executable.
8468 @deffn {Scheme Procedure} symbolic-link? @var{file}
8469 Return @code{#t} if @var{file} is a symbolic link (aka. a ``symlink'').
8472 @deffn {Scheme Procedure} elf-file? @var{file}
8473 @deffnx {Scheme Procedure} ar-file? @var{file}
8474 @deffnx {Scheme Procedure} gzip-file? @var{file}
8475 Return @code{#t} if @var{file} is, respectively, an ELF file, an
8476 @code{ar} archive (such as a @file{.a} static library), or a gzip file.
8479 @deffn {Scheme Procedure} reset-gzip-timestamp @var{file} [#:keep-mtime? #t]
8480 If @var{file} is a gzip file, reset its embedded timestamp (as with
8481 @command{gzip --no-name}) and return true. Otherwise return @code{#f}.
8482 When @var{keep-mtime?} is true, preserve @var{file}'s modification time.
8485 @subsection File Manipulation
8487 The following procedures and macros help create, modify, and delete
8488 files. They provide functionality comparable to common shell utilities
8489 such as @command{mkdir -p}, @command{cp -r}, @command{rm -r}, and
8490 @command{sed}. They complement Guile's extensive, but low-level, file
8491 system interface (@pxref{POSIX,,, guile, GNU Guile Reference Manual}).
8493 @deffn {Scheme Syntax} with-directory-excursion @var{directory} @var{body}@dots{}
8494 Run @var{body} with @var{directory} as the process's current directory.
8496 Essentially, this macro changes the current directory to @var{directory}
8497 before evaluating @var{body}, using @code{chdir} (@pxref{Processes,,,
8498 guile, GNU Guile Reference Manual}). It changes back to the initial
8499 directory when the dynamic extent of @var{body} is left, be it @i{via}
8500 normal procedure return or @i{via} a non-local exit such as an
8504 @deffn {Scheme Procedure} mkdir-p @var{dir}
8505 Create directory @var{dir} and all its ancestors.
8508 @deffn {Scheme Procedure} install-file @var{file} @var{directory}
8509 Create @var{directory} if it does not exist and copy @var{file} in there
8510 under the same name.
8513 @deffn {Scheme Procedure} make-file-writable @var{file}
8514 Make @var{file} writable for its owner.
8517 @deffn {Scheme Procedure} copy-recursively @var{source} @var{destination} @
8518 [#:log (current-output-port)] [#:follow-symlinks? #f] [#:keep-mtime? #f]
8519 Copy @var{source} directory to @var{destination}. Follow symlinks if
8520 @var{follow-symlinks?} is true; otherwise, just preserve them. When
8521 @var{keep-mtime?} is true, keep the modification time of the files in
8522 @var{source} on those of @var{destination}. Write verbose output to the
8526 @deffn {Scheme Procedure} delete-file-recursively @var{dir} @
8527 [#:follow-mounts? #f]
8528 Delete @var{dir} recursively, like @command{rm -rf}, without following
8529 symlinks. Don't follow mount points either, unless @var{follow-mounts?}
8530 is true. Report but ignore errors.
8533 @deffn {Scheme Syntax} substitute* @var{file} @
8534 ((@var{regexp} @var{match-var}@dots{}) @var{body}@dots{}) @dots{}
8535 Substitute @var{regexp} in @var{file} by the string returned by
8536 @var{body}. @var{body} is evaluated with each @var{match-var} bound to
8537 the corresponding positional regexp sub-expression. For example:
8543 (("foo([a-z]+)bar(.*)$" all letters end)
8544 (string-append "baz" letter end)))
8547 Here, anytime a line of @var{file} contains @code{hello}, it is replaced
8548 by @code{good morning}. Anytime a line of @var{file} matches the second
8549 regexp, @code{all} is bound to the complete match, @code{letters} is bound
8550 to the first sub-expression, and @code{end} is bound to the last one.
8552 When one of the @var{match-var} is @code{_}, no variable is bound to the
8553 corresponding match substring.
8555 Alternatively, @var{file} may be a list of file names, in which case
8556 they are all subject to the substitutions.
8558 Be careful about using @code{$} to match the end of a line; by itself it
8559 won't match the terminating newline of a line.
8562 @subsection File Search
8564 @cindex file, searching
8565 This section documents procedures to search and filter files.
8567 @deffn {Scheme Procedure} file-name-predicate @var{regexp}
8568 Return a predicate that returns true when passed a file name whose base
8569 name matches @var{regexp}.
8572 @deffn {Scheme Procedure} find-files @var{dir} [@var{pred}] @
8573 [#:stat lstat] [#:directories? #f] [#:fail-on-error? #f]
8574 Return the lexicographically sorted list of files under @var{dir} for
8575 which @var{pred} returns true. @var{pred} is passed two arguments: the
8576 absolute file name, and its stat buffer; the default predicate always
8577 returns true. @var{pred} can also be a regular expression, in which
8578 case it is equivalent to @code{(file-name-predicate @var{pred})}.
8579 @var{stat} is used to obtain file information; using @code{lstat} means
8580 that symlinks are not followed. If @var{directories?} is true, then
8581 directories will also be included. If @var{fail-on-error?} is true,
8582 raise an exception upon error.
8585 Here are a few examples where we assume that the current directory is
8586 the root of the Guix source tree:
8589 ;; List all the regular files in the current directory.
8591 @result{} ("./.dir-locals.el" "./.gitignore" @dots{})
8593 ;; List all the .scm files under gnu/services.
8594 (find-files "gnu/services" "\\.scm$")
8595 @result{} ("gnu/services/admin.scm" "gnu/services/audio.scm" @dots{})
8597 ;; List ar files in the current directory.
8598 (find-files "." (lambda (file stat) (ar-file? file)))
8599 @result{} ("./libformat.a" "./libstore.a" @dots{})
8602 @deffn {Scheme Procedure} which @var{program}
8603 Return the complete file name for @var{program} as found in
8604 @code{$PATH}, or @code{#f} if @var{program} could not be found.
8607 @subsection Build Phases
8609 @cindex build phases
8610 The @code{(guix build utils)} also contains tools to manipulate build
8611 phases as used by build systems (@pxref{Build Systems}). Build phases
8612 are represented as association lists or ``alists'' (@pxref{Association
8613 Lists,,, guile, GNU Guile Reference Manual}) where each key is a symbol
8614 naming the phase and the associated value is a procedure (@pxref{Build
8617 Guile core and the @code{(srfi srfi-1)} module both provide tools to
8618 manipulate alists. The @code{(guix build utils)} module complements
8619 those with tools written with build phases in mind.
8621 @cindex build phases, modifying
8622 @deffn {Scheme Syntax} modify-phases @var{phases} @var{clause}@dots{}
8623 Modify @var{phases} sequentially as per each @var{clause}, which may
8624 have one of the following forms:
8627 (delete @var{old-phase-name})
8628 (replace @var{old-phase-name} @var{new-phase})
8629 (add-before @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8630 (add-after @var{old-phase-name} @var{new-phase-name} @var{new-phase})
8633 Where every @var{phase-name} above is an expression evaluating to a
8634 symbol, and @var{new-phase} an expression evaluating to a procedure.
8637 The example below is taken from the definition of the @code{grep}
8638 package. It adds a phase to run after the @code{install} phase, called
8639 @code{fix-egrep-and-fgrep}. That phase is a procedure (@code{lambda*}
8640 is for anonymous procedures) that takes a @code{#:outputs} keyword
8641 argument and ignores extra keyword arguments (@pxref{Optional
8642 Arguments,,, guile, GNU Guile Reference Manual}, for more on
8643 @code{lambda*} and optional and keyword arguments.) The phase uses
8644 @code{substitute*} to modify the installed @file{egrep} and @file{fgrep}
8645 scripts so that they refer to @code{grep} by its absolute file name:
8648 (modify-phases %standard-phases
8649 (add-after 'install 'fix-egrep-and-fgrep
8650 ;; Patch 'egrep' and 'fgrep' to execute 'grep' via its
8651 ;; absolute file name instead of searching for it in $PATH.
8652 (lambda* (#:key outputs #:allow-other-keys)
8653 (let* ((out (assoc-ref outputs "out"))
8654 (bin (string-append out "/bin")))
8655 (substitute* (list (string-append bin "/egrep")
8656 (string-append bin "/fgrep"))
8658 (string-append "exec " bin "/grep")))
8662 In the example below, phases are modified in two ways: the standard
8663 @code{configure} phase is deleted, presumably because the package does
8664 not have a @file{configure} script or anything similar, and the default
8665 @code{install} phase is replaced by one that manually copies the
8666 executable files to be installed:
8669 (modify-phases %standard-phases
8670 (delete 'configure) ;no 'configure' script
8672 (lambda* (#:key outputs #:allow-other-keys)
8673 ;; The package's Makefile doesn't provide an "install"
8674 ;; rule so do it by ourselves.
8675 (let ((bin (string-append (assoc-ref outputs "out")
8677 (install-file "footswitch" bin)
8678 (install-file "scythe" bin)
8682 @c TODO: Add more examples.
8691 Conceptually, the @dfn{store} is the place where derivations that have
8692 been built successfully are stored---by default, @file{/gnu/store}.
8693 Sub-directories in the store are referred to as @dfn{store items} or
8694 sometimes @dfn{store paths}. The store has an associated database that
8695 contains information such as the store paths referred to by each store
8696 path, and the list of @emph{valid} store items---results of successful
8697 builds. This database resides in @file{@var{localstatedir}/guix/db},
8698 where @var{localstatedir} is the state directory specified @i{via}
8699 @option{--localstatedir} at configure time, usually @file{/var}.
8701 The store is @emph{always} accessed by the daemon on behalf of its clients
8702 (@pxref{Invoking guix-daemon}). To manipulate the store, clients
8703 connect to the daemon over a Unix-domain socket, send requests to it,
8704 and read the result---these are remote procedure calls, or RPCs.
8707 Users must @emph{never} modify files under @file{/gnu/store} directly.
8708 This would lead to inconsistencies and break the immutability
8709 assumptions of Guix's functional model (@pxref{Introduction}).
8711 @xref{Invoking guix gc, @command{guix gc --verify}}, for information on
8712 how to check the integrity of the store and attempt recovery from
8713 accidental modifications.
8716 The @code{(guix store)} module provides procedures to connect to the
8717 daemon, and to perform RPCs. These are described below. By default,
8718 @code{open-connection}, and thus all the @command{guix} commands,
8719 connect to the local daemon or to the URI specified by the
8720 @env{GUIX_DAEMON_SOCKET} environment variable.
8722 @defvr {Environment Variable} GUIX_DAEMON_SOCKET
8723 When set, the value of this variable should be a file name or a URI
8724 designating the daemon endpoint. When it is a file name, it denotes a
8725 Unix-domain socket to connect to. In addition to file names, the
8726 supported URI schemes are:
8731 These are for Unix-domain sockets.
8732 @code{file:///var/guix/daemon-socket/socket} is equivalent to
8733 @file{/var/guix/daemon-socket/socket}.
8736 @cindex daemon, remote access
8737 @cindex remote access to the daemon
8738 @cindex daemon, cluster setup
8739 @cindex clusters, daemon setup
8740 These URIs denote connections over TCP/IP, without encryption nor
8741 authentication of the remote host. The URI must specify the host name
8742 and optionally a port number (by default port 44146 is used):
8745 guix://master.guix.example.org:1234
8748 This setup is suitable on local networks, such as clusters, where only
8749 trusted nodes may connect to the build daemon at
8750 @code{master.guix.example.org}.
8752 The @option{--listen} option of @command{guix-daemon} can be used to
8753 instruct it to listen for TCP connections (@pxref{Invoking guix-daemon,
8754 @option{--listen}}).
8757 @cindex SSH access to build daemons
8758 These URIs allow you to connect to a remote daemon over SSH@. This
8759 feature requires Guile-SSH (@pxref{Requirements}) and a working
8760 @command{guile} binary in @env{PATH} on the destination machine. It
8761 supports public key and GSSAPI authentication. A typical URL might look
8765 ssh://charlie@@guix.example.org:22
8768 As for @command{guix copy}, the usual OpenSSH client configuration files
8769 are honored (@pxref{Invoking guix copy}).
8772 Additional URI schemes may be supported in the future.
8774 @c XXX: Remove this note when the protocol incurs fewer round trips
8775 @c and when (guix derivations) no longer relies on file system access.
8777 The ability to connect to remote build daemons is considered
8778 experimental as of @value{VERSION}. Please get in touch with us to
8779 share any problems or suggestions you may have (@pxref{Contributing}).
8783 @deffn {Scheme Procedure} open-connection [@var{uri}] [#:reserve-space? #t]
8784 Connect to the daemon over the Unix-domain socket at @var{uri} (a string). When
8785 @var{reserve-space?} is true, instruct it to reserve a little bit of
8786 extra space on the file system so that the garbage collector can still
8787 operate should the disk become full. Return a server object.
8789 @var{file} defaults to @code{%default-socket-path}, which is the normal
8790 location given the options that were passed to @command{configure}.
8793 @deffn {Scheme Procedure} close-connection @var{server}
8794 Close the connection to @var{server}.
8797 @defvr {Scheme Variable} current-build-output-port
8798 This variable is bound to a SRFI-39 parameter, which refers to the port
8799 where build and error logs sent by the daemon should be written.
8802 Procedures that make RPCs all take a server object as their first
8805 @deffn {Scheme Procedure} valid-path? @var{server} @var{path}
8806 @cindex invalid store items
8807 Return @code{#t} when @var{path} designates a valid store item and
8808 @code{#f} otherwise (an invalid item may exist on disk but still be
8809 invalid, for instance because it is the result of an aborted or failed
8812 A @code{&store-protocol-error} condition is raised if @var{path} is not
8813 prefixed by the store directory (@file{/gnu/store}).
8816 @deffn {Scheme Procedure} add-text-to-store @var{server} @var{name} @var{text} [@var{references}]
8817 Add @var{text} under file @var{name} in the store, and return its store
8818 path. @var{references} is the list of store paths referred to by the
8819 resulting store path.
8822 @deffn {Scheme Procedure} build-derivations @var{store} @var{derivations} @
8824 Build @var{derivations}, a list of @code{<derivation>} objects, @file{.drv}
8825 file names, or derivation/output pairs, using the specified
8826 @var{mode}---@code{(build-mode normal)} by default.
8829 Note that the @code{(guix monads)} module provides a monad as well as
8830 monadic versions of the above procedures, with the goal of making it
8831 more convenient to work with code that accesses the store (@pxref{The
8835 @i{This section is currently incomplete.}
8838 @section Derivations
8841 Low-level build actions and the environment in which they are performed
8842 are represented by @dfn{derivations}. A derivation contains the
8843 following pieces of information:
8847 The outputs of the derivation---derivations produce at least one file or
8848 directory in the store, but may produce more.
8851 @cindex build-time dependencies
8852 @cindex dependencies, build-time
8853 The inputs of the derivations---i.e., its build-time dependencies---which may
8854 be other derivations or plain files in the store (patches, build scripts,
8858 The system type targeted by the derivation---e.g., @code{x86_64-linux}.
8861 The file name of a build script in the store, along with the arguments
8865 A list of environment variables to be defined.
8869 @cindex derivation path
8870 Derivations allow clients of the daemon to communicate build actions to
8871 the store. They exist in two forms: as an in-memory representation,
8872 both on the client- and daemon-side, and as files in the store whose
8873 name end in @file{.drv}---these files are referred to as @dfn{derivation
8874 paths}. Derivations paths can be passed to the @code{build-derivations}
8875 procedure to perform the build actions they prescribe (@pxref{The
8878 @cindex fixed-output derivations
8879 Operations such as file downloads and version-control checkouts for
8880 which the expected content hash is known in advance are modeled as
8881 @dfn{fixed-output derivations}. Unlike regular derivations, the outputs
8882 of a fixed-output derivation are independent of its inputs---e.g., a
8883 source code download produces the same result regardless of the download
8884 method and tools being used.
8887 @cindex run-time dependencies
8888 @cindex dependencies, run-time
8889 The outputs of derivations---i.e., the build results---have a set of
8890 @dfn{references}, as reported by the @code{references} RPC or the
8891 @command{guix gc --references} command (@pxref{Invoking guix gc}). References
8892 are the set of run-time dependencies of the build results. References are a
8893 subset of the inputs of the derivation; this subset is automatically computed
8894 by the build daemon by scanning all the files in the outputs.
8896 The @code{(guix derivations)} module provides a representation of
8897 derivations as Scheme objects, along with procedures to create and
8898 otherwise manipulate derivations. The lowest-level primitive to create
8899 a derivation is the @code{derivation} procedure:
8901 @deffn {Scheme Procedure} derivation @var{store} @var{name} @var{builder} @
8902 @var{args} [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8903 [#:recursive? #f] [#:inputs '()] [#:env-vars '()] @
8904 [#:system (%current-system)] [#:references-graphs #f] @
8905 [#:allowed-references #f] [#:disallowed-references #f] @
8906 [#:leaked-env-vars #f] [#:local-build? #f] @
8907 [#:substitutable? #t] [#:properties '()]
8908 Build a derivation with the given arguments, and return the resulting
8909 @code{<derivation>} object.
8911 When @var{hash} and @var{hash-algo} are given, a
8912 @dfn{fixed-output derivation} is created---i.e., one whose result is
8913 known in advance, such as a file download. If, in addition,
8914 @var{recursive?} is true, then that fixed output may be an executable
8915 file or a directory and @var{hash} must be the hash of an archive
8916 containing this output.
8918 When @var{references-graphs} is true, it must be a list of file
8919 name/store path pairs. In that case, the reference graph of each store
8920 path is exported in the build environment in the corresponding file, in
8921 a simple text format.
8923 When @var{allowed-references} is true, it must be a list of store items
8924 or outputs that the derivation's output may refer to. Likewise,
8925 @var{disallowed-references}, if true, must be a list of things the
8926 outputs may @emph{not} refer to.
8928 When @var{leaked-env-vars} is true, it must be a list of strings
8929 denoting environment variables that are allowed to ``leak'' from the
8930 daemon's environment to the build environment. This is only applicable
8931 to fixed-output derivations---i.e., when @var{hash} is true. The main
8932 use is to allow variables such as @code{http_proxy} to be passed to
8933 derivations that download files.
8935 When @var{local-build?} is true, declare that the derivation is not a
8936 good candidate for offloading and should rather be built locally
8937 (@pxref{Daemon Offload Setup}). This is the case for small derivations
8938 where the costs of data transfers would outweigh the benefits.
8940 When @var{substitutable?} is false, declare that substitutes of the
8941 derivation's output should not be used (@pxref{Substitutes}). This is
8942 useful, for instance, when building packages that capture details of the
8943 host CPU instruction set.
8945 @var{properties} must be an association list describing ``properties'' of the
8946 derivation. It is kept as-is, uninterpreted, in the derivation.
8950 Here's an example with a shell script as its builder, assuming
8951 @var{store} is an open connection to the daemon, and @var{bash} points
8952 to a Bash executable in the store:
8955 (use-modules (guix utils)
8959 (let ((builder ; add the Bash script to the store
8960 (add-text-to-store store "my-builder.sh"
8961 "echo hello world > $out\n" '())))
8962 (derivation store "foo"
8963 bash `("-e" ,builder)
8964 #:inputs `((,bash) (,builder))
8965 #:env-vars '(("HOME" . "/homeless"))))
8966 @result{} #<derivation /gnu/store/@dots{}-foo.drv => /gnu/store/@dots{}-foo>
8969 As can be guessed, this primitive is cumbersome to use directly. A
8970 better approach is to write build scripts in Scheme, of course! The
8971 best course of action for that is to write the build code as a
8972 ``G-expression'', and to pass it to @code{gexp->derivation}. For more
8973 information, @pxref{G-Expressions}.
8975 Once upon a time, @code{gexp->derivation} did not exist and constructing
8976 derivations with build code written in Scheme was achieved with
8977 @code{build-expression->derivation}, documented below. This procedure
8978 is now deprecated in favor of the much nicer @code{gexp->derivation}.
8980 @deffn {Scheme Procedure} build-expression->derivation @var{store} @
8981 @var{name} @var{exp} @
8982 [#:system (%current-system)] [#:inputs '()] @
8983 [#:outputs '("out")] [#:hash #f] [#:hash-algo #f] @
8984 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
8985 [#:references-graphs #f] [#:allowed-references #f] @
8986 [#:disallowed-references #f] @
8987 [#:local-build? #f] [#:substitutable? #t] [#:guile-for-build #f]
8988 Return a derivation that executes Scheme expression @var{exp} as a
8989 builder for derivation @var{name}. @var{inputs} must be a list of
8990 @code{(name drv-path sub-drv)} tuples; when @var{sub-drv} is omitted,
8991 @code{"out"} is assumed. @var{modules} is a list of names of Guile
8992 modules from the current search path to be copied in the store,
8993 compiled, and made available in the load path during the execution of
8994 @var{exp}---e.g., @code{((guix build utils) (guix build
8995 gnu-build-system))}.
8997 @var{exp} is evaluated in an environment where @code{%outputs} is bound
8998 to a list of output/path pairs, and where @code{%build-inputs} is bound
8999 to a list of string/output-path pairs made from @var{inputs}.
9000 Optionally, @var{env-vars} is a list of string pairs specifying the name
9001 and value of environment variables visible to the builder. The builder
9002 terminates by passing the result of @var{exp} to @code{exit}; thus, when
9003 @var{exp} returns @code{#f}, the build is considered to have failed.
9005 @var{exp} is built using @var{guile-for-build} (a derivation). When
9006 @var{guile-for-build} is omitted or is @code{#f}, the value of the
9007 @code{%guile-for-build} fluid is used instead.
9009 See the @code{derivation} procedure for the meaning of
9010 @var{references-graphs}, @var{allowed-references},
9011 @var{disallowed-references}, @var{local-build?}, and
9012 @var{substitutable?}.
9016 Here's an example of a single-output derivation that creates a directory
9017 containing one file:
9020 (let ((builder '(let ((out (assoc-ref %outputs "out")))
9021 (mkdir out) ; create /gnu/store/@dots{}-goo
9022 (call-with-output-file (string-append out "/test")
9024 (display '(hello guix) p))))))
9025 (build-expression->derivation store "goo" builder))
9027 @result{} #<derivation /gnu/store/@dots{}-goo.drv => @dots{}>
9031 @node The Store Monad
9032 @section The Store Monad
9036 The procedures that operate on the store described in the previous
9037 sections all take an open connection to the build daemon as their first
9038 argument. Although the underlying model is functional, they either have
9039 side effects or depend on the current state of the store.
9041 The former is inconvenient: the connection to the build daemon has to be
9042 carried around in all those functions, making it impossible to compose
9043 functions that do not take that parameter with functions that do. The
9044 latter can be problematic: since store operations have side effects
9045 and/or depend on external state, they have to be properly sequenced.
9047 @cindex monadic values
9048 @cindex monadic functions
9049 This is where the @code{(guix monads)} module comes in. This module
9050 provides a framework for working with @dfn{monads}, and a particularly
9051 useful monad for our uses, the @dfn{store monad}. Monads are a
9052 construct that allows two things: associating ``context'' with values
9053 (in our case, the context is the store), and building sequences of
9054 computations (here computations include accesses to the store). Values
9055 in a monad---values that carry this additional context---are called
9056 @dfn{monadic values}; procedures that return such values are called
9057 @dfn{monadic procedures}.
9059 Consider this ``normal'' procedure:
9062 (define (sh-symlink store)
9063 ;; Return a derivation that symlinks the 'bash' executable.
9064 (let* ((drv (package-derivation store bash))
9065 (out (derivation->output-path drv))
9066 (sh (string-append out "/bin/bash")))
9067 (build-expression->derivation store "sh"
9068 `(symlink ,sh %output))))
9071 Using @code{(guix monads)} and @code{(guix gexp)}, it may be rewritten
9072 as a monadic function:
9075 (define (sh-symlink)
9076 ;; Same, but return a monadic value.
9077 (mlet %store-monad ((drv (package->derivation bash)))
9078 (gexp->derivation "sh"
9079 #~(symlink (string-append #$drv "/bin/bash")
9083 There are several things to note in the second version: the @code{store}
9084 parameter is now implicit and is ``threaded'' in the calls to the
9085 @code{package->derivation} and @code{gexp->derivation} monadic
9086 procedures, and the monadic value returned by @code{package->derivation}
9087 is @dfn{bound} using @code{mlet} instead of plain @code{let}.
9089 As it turns out, the call to @code{package->derivation} can even be
9090 omitted since it will take place implicitly, as we will see later
9091 (@pxref{G-Expressions}):
9094 (define (sh-symlink)
9095 (gexp->derivation "sh"
9096 #~(symlink (string-append #$bash "/bin/bash")
9101 @c <https://syntaxexclamation.wordpress.com/2014/06/26/escaping-continuations/>
9102 @c for the funny quote.
9103 Calling the monadic @code{sh-symlink} has no effect. As someone once
9104 said, ``you exit a monad like you exit a building on fire: by running''.
9105 So, to exit the monad and get the desired effect, one must use
9106 @code{run-with-store}:
9109 (run-with-store (open-connection) (sh-symlink))
9110 @result{} /gnu/store/...-sh-symlink
9113 Note that the @code{(guix monad-repl)} module extends the Guile REPL with
9114 new ``meta-commands'' to make it easier to deal with monadic procedures:
9115 @code{run-in-store}, and @code{enter-store-monad}. The former is used
9116 to ``run'' a single monadic value through the store:
9119 scheme@@(guile-user)> ,run-in-store (package->derivation hello)
9120 $1 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
9123 The latter enters a recursive REPL, where all the return values are
9124 automatically run through the store:
9127 scheme@@(guile-user)> ,enter-store-monad
9128 store-monad@@(guile-user) [1]> (package->derivation hello)
9129 $2 = #<derivation /gnu/store/@dots{}-hello-2.9.drv => @dots{}>
9130 store-monad@@(guile-user) [1]> (text-file "foo" "Hello!")
9131 $3 = "/gnu/store/@dots{}-foo"
9132 store-monad@@(guile-user) [1]> ,q
9133 scheme@@(guile-user)>
9137 Note that non-monadic values cannot be returned in the
9138 @code{store-monad} REPL.
9140 The main syntactic forms to deal with monads in general are provided by
9141 the @code{(guix monads)} module and are described below.
9143 @deffn {Scheme Syntax} with-monad @var{monad} @var{body} ...
9144 Evaluate any @code{>>=} or @code{return} forms in @var{body} as being
9148 @deffn {Scheme Syntax} return @var{val}
9149 Return a monadic value that encapsulates @var{val}.
9152 @deffn {Scheme Syntax} >>= @var{mval} @var{mproc} ...
9153 @dfn{Bind} monadic value @var{mval}, passing its ``contents'' to monadic
9154 procedures @var{mproc}@dots{}@footnote{This operation is commonly
9155 referred to as ``bind'', but that name denotes an unrelated procedure in
9156 Guile. Thus we use this somewhat cryptic symbol inherited from the
9157 Haskell language.}. There can be one @var{mproc} or several of them, as
9162 (with-monad %state-monad
9164 (lambda (x) (return (+ 1 x)))
9165 (lambda (x) (return (* 2 x)))))
9169 @result{} some-state
9173 @deffn {Scheme Syntax} mlet @var{monad} ((@var{var} @var{mval}) ...) @
9175 @deffnx {Scheme Syntax} mlet* @var{monad} ((@var{var} @var{mval}) ...) @
9177 Bind the variables @var{var} to the monadic values @var{mval} in
9178 @var{body}, which is a sequence of expressions. As with the bind
9179 operator, this can be thought of as ``unpacking'' the raw, non-monadic
9180 value ``contained'' in @var{mval} and making @var{var} refer to that
9181 raw, non-monadic value within the scope of the @var{body}. The form
9182 (@var{var} -> @var{val}) binds @var{var} to the ``normal'' value
9183 @var{val}, as per @code{let}. The binding operations occur in sequence
9184 from left to right. The last expression of @var{body} must be a monadic
9185 expression, and its result will become the result of the @code{mlet} or
9186 @code{mlet*} when run in the @var{monad}.
9188 @code{mlet*} is to @code{mlet} what @code{let*} is to @code{let}
9189 (@pxref{Local Bindings,,, guile, GNU Guile Reference Manual}).
9192 @deffn {Scheme System} mbegin @var{monad} @var{mexp} ...
9193 Bind @var{mexp} and the following monadic expressions in sequence,
9194 returning the result of the last expression. Every expression in the
9195 sequence must be a monadic expression.
9197 This is akin to @code{mlet}, except that the return values of the
9198 monadic expressions are ignored. In that sense, it is analogous to
9199 @code{begin}, but applied to monadic expressions.
9202 @deffn {Scheme System} mwhen @var{condition} @var{mexp0} @var{mexp*} ...
9203 When @var{condition} is true, evaluate the sequence of monadic
9204 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9205 @var{condition} is false, return @code{*unspecified*} in the current
9206 monad. Every expression in the sequence must be a monadic expression.
9209 @deffn {Scheme System} munless @var{condition} @var{mexp0} @var{mexp*} ...
9210 When @var{condition} is false, evaluate the sequence of monadic
9211 expressions @var{mexp0}..@var{mexp*} as in an @code{mbegin}. When
9212 @var{condition} is true, return @code{*unspecified*} in the current
9213 monad. Every expression in the sequence must be a monadic expression.
9217 The @code{(guix monads)} module provides the @dfn{state monad}, which
9218 allows an additional value---the state---to be @emph{threaded} through
9219 monadic procedure calls.
9221 @defvr {Scheme Variable} %state-monad
9222 The state monad. Procedures in the state monad can access and change
9223 the state that is threaded.
9225 Consider the example below. The @code{square} procedure returns a value
9226 in the state monad. It returns the square of its argument, but also
9227 increments the current state value:
9231 (mlet %state-monad ((count (current-state)))
9232 (mbegin %state-monad
9233 (set-current-state (+ 1 count))
9236 (run-with-state (sequence %state-monad (map square (iota 3))) 0)
9241 When ``run'' through @code{%state-monad}, we obtain that additional state
9242 value, which is the number of @code{square} calls.
9245 @deffn {Monadic Procedure} current-state
9246 Return the current state as a monadic value.
9249 @deffn {Monadic Procedure} set-current-state @var{value}
9250 Set the current state to @var{value} and return the previous state as a
9254 @deffn {Monadic Procedure} state-push @var{value}
9255 Push @var{value} to the current state, which is assumed to be a list,
9256 and return the previous state as a monadic value.
9259 @deffn {Monadic Procedure} state-pop
9260 Pop a value from the current state and return it as a monadic value.
9261 The state is assumed to be a list.
9264 @deffn {Scheme Procedure} run-with-state @var{mval} [@var{state}]
9265 Run monadic value @var{mval} starting with @var{state} as the initial
9266 state. Return two values: the resulting value, and the resulting state.
9269 The main interface to the store monad, provided by the @code{(guix
9270 store)} module, is as follows.
9272 @defvr {Scheme Variable} %store-monad
9273 The store monad---an alias for @code{%state-monad}.
9275 Values in the store monad encapsulate accesses to the store. When its
9276 effect is needed, a value of the store monad must be ``evaluated'' by
9277 passing it to the @code{run-with-store} procedure (see below).
9280 @deffn {Scheme Procedure} run-with-store @var{store} @var{mval} [#:guile-for-build] [#:system (%current-system)]
9281 Run @var{mval}, a monadic value in the store monad, in @var{store}, an
9282 open store connection.
9285 @deffn {Monadic Procedure} text-file @var{name} @var{text} [@var{references}]
9286 Return as a monadic value the absolute file name in the store of the file
9287 containing @var{text}, a string. @var{references} is a list of store items that the
9288 resulting text file refers to; it defaults to the empty list.
9291 @deffn {Monadic Procedure} binary-file @var{name} @var{data} [@var{references}]
9292 Return as a monadic value the absolute file name in the store of the file
9293 containing @var{data}, a bytevector. @var{references} is a list of store
9294 items that the resulting binary file refers to; it defaults to the empty list.
9297 @deffn {Monadic Procedure} interned-file @var{file} [@var{name}] @
9298 [#:recursive? #t] [#:select? (const #t)]
9299 Return the name of @var{file} once interned in the store. Use
9300 @var{name} as its store name, or the basename of @var{file} if
9301 @var{name} is omitted.
9303 When @var{recursive?} is true, the contents of @var{file} are added
9304 recursively; if @var{file} designates a flat file and @var{recursive?}
9305 is true, its contents are added, and its permission bits are kept.
9307 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9308 @var{stat})} for each directory entry, where @var{file} is the entry's
9309 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9310 entries for which @var{select?} does not return true.
9312 The example below adds a file to the store, under two different names:
9315 (run-with-store (open-connection)
9316 (mlet %store-monad ((a (interned-file "README"))
9317 (b (interned-file "README" "LEGU-MIN")))
9318 (return (list a b))))
9320 @result{} ("/gnu/store/rwm@dots{}-README" "/gnu/store/44i@dots{}-LEGU-MIN")
9325 The @code{(guix packages)} module exports the following package-related
9328 @deffn {Monadic Procedure} package-file @var{package} [@var{file}] @
9329 [#:system (%current-system)] [#:target #f] @
9332 value in the absolute file name of @var{file} within the @var{output}
9333 directory of @var{package}. When @var{file} is omitted, return the name
9334 of the @var{output} directory of @var{package}. When @var{target} is
9335 true, use it as a cross-compilation target triplet.
9337 Note that this procedure does @emph{not} build @var{package}. Thus, the
9338 result might or might not designate an existing file. We recommend not
9339 using this procedure unless you know what you are doing.
9342 @deffn {Monadic Procedure} package->derivation @var{package} [@var{system}]
9343 @deffnx {Monadic Procedure} package->cross-derivation @var{package} @
9344 @var{target} [@var{system}]
9345 Monadic version of @code{package-derivation} and
9346 @code{package-cross-derivation} (@pxref{Defining Packages}).
9351 @section G-Expressions
9353 @cindex G-expression
9354 @cindex build code quoting
9355 So we have ``derivations'', which represent a sequence of build actions
9356 to be performed to produce an item in the store (@pxref{Derivations}).
9357 These build actions are performed when asking the daemon to actually
9358 build the derivations; they are run by the daemon in a container
9359 (@pxref{Invoking guix-daemon}).
9361 @cindex code staging
9362 @cindex staging, of code
9363 @cindex strata of code
9364 It should come as no surprise that we like to write these build actions
9365 in Scheme. When we do that, we end up with two @dfn{strata} of Scheme
9366 code@footnote{The term @dfn{stratum} in this context was coined by
9367 Manuel Serrano et al.@: in the context of their work on Hop. Oleg
9368 Kiselyov, who has written insightful
9369 @url{http://okmij.org/ftp/meta-programming/#meta-scheme, essays and code
9370 on this topic}, refers to this kind of code generation as
9371 @dfn{staging}.}: the ``host code''---code that defines packages, talks
9372 to the daemon, etc.---and the ``build code''---code that actually
9373 performs build actions, such as making directories, invoking
9374 @command{make}, and so on (@pxref{Build Phases}).
9376 To describe a derivation and its build actions, one typically needs to
9377 embed build code inside host code. It boils down to manipulating build
9378 code as data, and the homoiconicity of Scheme---code has a direct
9379 representation as data---comes in handy for that. But we need more than
9380 the normal @code{quasiquote} mechanism in Scheme to construct build
9383 The @code{(guix gexp)} module implements @dfn{G-expressions}, a form of
9384 S-expressions adapted to build expressions. G-expressions, or
9385 @dfn{gexps}, consist essentially of three syntactic forms: @code{gexp},
9386 @code{ungexp}, and @code{ungexp-splicing} (or simply: @code{#~},
9387 @code{#$}, and @code{#$@@}), which are comparable to
9388 @code{quasiquote}, @code{unquote}, and @code{unquote-splicing},
9389 respectively (@pxref{Expression Syntax, @code{quasiquote},, guile,
9390 GNU Guile Reference Manual}). However, there are major differences:
9394 Gexps are meant to be written to a file and run or manipulated by other
9398 When a high-level object such as a package or derivation is unquoted
9399 inside a gexp, the result is as if its output file name had been
9403 Gexps carry information about the packages or derivations they refer to,
9404 and these dependencies are automatically added as inputs to the build
9405 processes that use them.
9408 @cindex lowering, of high-level objects in gexps
9409 This mechanism is not limited to package and derivation
9410 objects: @dfn{compilers} able to ``lower'' other high-level objects to
9411 derivations or files in the store can be defined,
9412 such that these objects can also be inserted
9413 into gexps. For example, a useful type of high-level objects that can be
9414 inserted in a gexp is ``file-like objects'', which make it easy to
9415 add files to the store and to refer to them in
9416 derivations and such (see @code{local-file} and @code{plain-file}
9419 To illustrate the idea, here is an example of a gexp:
9426 (symlink (string-append #$coreutils "/bin/ls")
9430 This gexp can be passed to @code{gexp->derivation}; we obtain a
9431 derivation that builds a directory containing exactly one symlink to
9432 @file{/gnu/store/@dots{}-coreutils-8.22/bin/ls}:
9435 (gexp->derivation "the-thing" build-exp)
9438 As one would expect, the @code{"/gnu/store/@dots{}-coreutils-8.22"} string is
9439 substituted to the reference to the @var{coreutils} package in the
9440 actual build code, and @var{coreutils} is automatically made an input to
9441 the derivation. Likewise, @code{#$output} (equivalent to @code{(ungexp
9442 output)}) is replaced by a string containing the directory name of the
9443 output of the derivation.
9445 @cindex cross compilation
9446 In a cross-compilation context, it is useful to distinguish between
9447 references to the @emph{native} build of a package---that can run on the
9448 host---versus references to cross builds of a package. To that end, the
9449 @code{#+} plays the same role as @code{#$}, but is a reference to a
9450 native package build:
9453 (gexp->derivation "vi"
9456 (mkdir (string-append #$output "/bin"))
9457 (system* (string-append #+coreutils "/bin/ln")
9459 (string-append #$emacs "/bin/emacs")
9460 (string-append #$output "/bin/vi")))
9461 #:target "aarch64-linux-gnu")
9465 In the example above, the native build of @var{coreutils} is used, so
9466 that @command{ln} can actually run on the host; but then the
9467 cross-compiled build of @var{emacs} is referenced.
9469 @cindex imported modules, for gexps
9470 @findex with-imported-modules
9471 Another gexp feature is @dfn{imported modules}: sometimes you want to be
9472 able to use certain Guile modules from the ``host environment'' in the
9473 gexp, so those modules should be imported in the ``build environment''.
9474 The @code{with-imported-modules} form allows you to express that:
9477 (let ((build (with-imported-modules '((guix build utils))
9479 (use-modules (guix build utils))
9480 (mkdir-p (string-append #$output "/bin"))))))
9481 (gexp->derivation "empty-dir"
9484 (display "success!\n")
9489 In this example, the @code{(guix build utils)} module is automatically
9490 pulled into the isolated build environment of our gexp, such that
9491 @code{(use-modules (guix build utils))} works as expected.
9493 @cindex module closure
9494 @findex source-module-closure
9495 Usually you want the @emph{closure} of the module to be imported---i.e.,
9496 the module itself and all the modules it depends on---rather than just
9497 the module; failing to do that, attempts to use the module will fail
9498 because of missing dependent modules. The @code{source-module-closure}
9499 procedure computes the closure of a module by looking at its source file
9500 headers, which comes in handy in this case:
9503 (use-modules (guix modules)) ;for 'source-module-closure'
9505 (with-imported-modules (source-module-closure
9506 '((guix build utils)
9508 (gexp->derivation "something-with-vms"
9510 (use-modules (guix build utils)
9515 @cindex extensions, for gexps
9516 @findex with-extensions
9517 In the same vein, sometimes you want to import not just pure-Scheme
9518 modules, but also ``extensions'' such as Guile bindings to C libraries
9519 or other ``full-blown'' packages. Say you need the @code{guile-json}
9520 package available on the build side, here's how you would do it:
9523 (use-modules (gnu packages guile)) ;for 'guile-json'
9525 (with-extensions (list guile-json)
9526 (gexp->derivation "something-with-json"
9528 (use-modules (json))
9532 The syntactic form to construct gexps is summarized below.
9534 @deffn {Scheme Syntax} #~@var{exp}
9535 @deffnx {Scheme Syntax} (gexp @var{exp})
9536 Return a G-expression containing @var{exp}. @var{exp} may contain one
9537 or more of the following forms:
9541 @itemx (ungexp @var{obj})
9542 Introduce a reference to @var{obj}. @var{obj} may have one of the
9543 supported types, for example a package or a
9544 derivation, in which case the @code{ungexp} form is replaced by its
9545 output file name---e.g., @code{"/gnu/store/@dots{}-coreutils-8.22}.
9547 If @var{obj} is a list, it is traversed and references to supported
9548 objects are substituted similarly.
9550 If @var{obj} is another gexp, its contents are inserted and its
9551 dependencies are added to those of the containing gexp.
9553 If @var{obj} is another kind of object, it is inserted as is.
9555 @item #$@var{obj}:@var{output}
9556 @itemx (ungexp @var{obj} @var{output})
9557 This is like the form above, but referring explicitly to the
9558 @var{output} of @var{obj}---this is useful when @var{obj} produces
9559 multiple outputs (@pxref{Packages with Multiple Outputs}).
9562 @itemx #+@var{obj}:output
9563 @itemx (ungexp-native @var{obj})
9564 @itemx (ungexp-native @var{obj} @var{output})
9565 Same as @code{ungexp}, but produces a reference to the @emph{native}
9566 build of @var{obj} when used in a cross compilation context.
9568 @item #$output[:@var{output}]
9569 @itemx (ungexp output [@var{output}])
9570 Insert a reference to derivation output @var{output}, or to the main
9571 output when @var{output} is omitted.
9573 This only makes sense for gexps passed to @code{gexp->derivation}.
9576 @itemx (ungexp-splicing @var{lst})
9577 Like the above, but splices the contents of @var{lst} inside the
9581 @itemx (ungexp-native-splicing @var{lst})
9582 Like the above, but refers to native builds of the objects listed in
9587 G-expressions created by @code{gexp} or @code{#~} are run-time objects
9588 of the @code{gexp?} type (see below).
9591 @deffn {Scheme Syntax} with-imported-modules @var{modules} @var{body}@dots{}
9592 Mark the gexps defined in @var{body}@dots{} as requiring @var{modules}
9593 in their execution environment.
9595 Each item in @var{modules} can be the name of a module, such as
9596 @code{(guix build utils)}, or it can be a module name, followed by an
9597 arrow, followed by a file-like object:
9600 `((guix build utils)
9602 ((guix config) => ,(scheme-file "config.scm"
9603 #~(define-module @dots{}))))
9607 In the example above, the first two modules are taken from the search
9608 path, and the last one is created from the given file-like object.
9610 This form has @emph{lexical} scope: it has an effect on the gexps
9611 directly defined in @var{body}@dots{}, but not on those defined, say, in
9612 procedures called from @var{body}@dots{}.
9615 @deffn {Scheme Syntax} with-extensions @var{extensions} @var{body}@dots{}
9616 Mark the gexps defined in @var{body}@dots{} as requiring
9617 @var{extensions} in their build and execution environment.
9618 @var{extensions} is typically a list of package objects such as those
9619 defined in the @code{(gnu packages guile)} module.
9621 Concretely, the packages listed in @var{extensions} are added to the
9622 load path while compiling imported modules in @var{body}@dots{}; they
9623 are also added to the load path of the gexp returned by
9627 @deffn {Scheme Procedure} gexp? @var{obj}
9628 Return @code{#t} if @var{obj} is a G-expression.
9631 G-expressions are meant to be written to disk, either as code building
9632 some derivation, or as plain files in the store. The monadic procedures
9633 below allow you to do that (@pxref{The Store Monad}, for more
9634 information about monads).
9636 @deffn {Monadic Procedure} gexp->derivation @var{name} @var{exp} @
9637 [#:system (%current-system)] [#:target #f] [#:graft? #t] @
9638 [#:hash #f] [#:hash-algo #f] @
9639 [#:recursive? #f] [#:env-vars '()] [#:modules '()] @
9640 [#:module-path @code{%load-path}] @
9641 [#:effective-version "2.2"] @
9642 [#:references-graphs #f] [#:allowed-references #f] @
9643 [#:disallowed-references #f] @
9644 [#:leaked-env-vars #f] @
9645 [#:script-name (string-append @var{name} "-builder")] @
9646 [#:deprecation-warnings #f] @
9647 [#:local-build? #f] [#:substitutable? #t] @
9648 [#:properties '()] [#:guile-for-build #f]
9649 Return a derivation @var{name} that runs @var{exp} (a gexp) with
9650 @var{guile-for-build} (a derivation) on @var{system}; @var{exp} is
9651 stored in a file called @var{script-name}. When @var{target} is true,
9652 it is used as the cross-compilation target triplet for packages referred
9655 @var{modules} is deprecated in favor of @code{with-imported-modules}.
9657 make @var{modules} available in the evaluation context of @var{exp};
9658 @var{modules} is a list of names of Guile modules searched in
9659 @var{module-path} to be copied in the store, compiled, and made available in
9660 the load path during the execution of @var{exp}---e.g., @code{((guix
9661 build utils) (guix build gnu-build-system))}.
9663 @var{effective-version} determines the string to use when adding extensions of
9664 @var{exp} (see @code{with-extensions}) to the search path---e.g., @code{"2.2"}.
9666 @var{graft?} determines whether packages referred to by @var{exp} should be grafted when
9669 When @var{references-graphs} is true, it must be a list of tuples of one of the
9673 (@var{file-name} @var{package})
9674 (@var{file-name} @var{package} @var{output})
9675 (@var{file-name} @var{derivation})
9676 (@var{file-name} @var{derivation} @var{output})
9677 (@var{file-name} @var{store-item})
9680 The right-hand-side of each element of @var{references-graphs} is automatically made
9681 an input of the build process of @var{exp}. In the build environment, each
9682 @var{file-name} contains the reference graph of the corresponding item, in a simple
9685 @var{allowed-references} must be either @code{#f} or a list of output names and packages.
9686 In the latter case, the list denotes store items that the result is allowed to
9687 refer to. Any reference to another store item will lead to a build error.
9688 Similarly for @var{disallowed-references}, which can list items that must not be
9689 referenced by the outputs.
9691 @var{deprecation-warnings} determines whether to show deprecation warnings while
9692 compiling modules. It can be @code{#f}, @code{#t}, or @code{'detailed}.
9694 The other arguments are as for @code{derivation} (@pxref{Derivations}).
9697 @cindex file-like objects
9698 The @code{local-file}, @code{plain-file}, @code{computed-file},
9699 @code{program-file}, and @code{scheme-file} procedures below return
9700 @dfn{file-like objects}. That is, when unquoted in a G-expression,
9701 these objects lead to a file in the store. Consider this G-expression:
9704 #~(system* #$(file-append glibc "/sbin/nscd") "-f"
9705 #$(local-file "/tmp/my-nscd.conf"))
9708 The effect here is to ``intern'' @file{/tmp/my-nscd.conf} by copying it
9709 to the store. Once expanded, for instance @i{via}
9710 @code{gexp->derivation}, the G-expression refers to that copy under
9711 @file{/gnu/store}; thus, modifying or removing the file in @file{/tmp}
9712 does not have any effect on what the G-expression does.
9713 @code{plain-file} can be used similarly; it differs in that the file
9714 content is directly passed as a string.
9716 @deffn {Scheme Procedure} local-file @var{file} [@var{name}] @
9717 [#:recursive? #f] [#:select? (const #t)]
9718 Return an object representing local file @var{file} to add to the store;
9719 this object can be used in a gexp. If @var{file} is a literal string
9720 denoting a relative file name, it is looked up relative to the source
9721 file where it appears; if @var{file} is not a literal string, it is
9722 looked up relative to the current working directory at run time.
9723 @var{file} will be added to the store under @var{name}--by default the
9724 base name of @var{file}.
9726 When @var{recursive?} is true, the contents of @var{file} are added recursively; if @var{file}
9727 designates a flat file and @var{recursive?} is true, its contents are added, and its
9728 permission bits are kept.
9730 When @var{recursive?} is true, call @code{(@var{select?} @var{file}
9731 @var{stat})} for each directory entry, where @var{file} is the entry's
9732 absolute file name and @var{stat} is the result of @code{lstat}; exclude
9733 entries for which @var{select?} does not return true.
9735 This is the declarative counterpart of the @code{interned-file} monadic
9736 procedure (@pxref{The Store Monad, @code{interned-file}}).
9739 @deffn {Scheme Procedure} plain-file @var{name} @var{content}
9740 Return an object representing a text file called @var{name} with the given
9741 @var{content} (a string or a bytevector) to be added to the store.
9743 This is the declarative counterpart of @code{text-file}.
9746 @deffn {Scheme Procedure} computed-file @var{name} @var{gexp} @
9749 Return an object representing the store item @var{name}, a file or
9750 directory computed by @var{gexp}. When @var{local-build?} is true (the
9751 default), the derivation is built locally. @var{options} is a list of
9752 additional arguments to pass to @code{gexp->derivation}.
9754 This is the declarative counterpart of @code{gexp->derivation}.
9757 @deffn {Monadic Procedure} gexp->script @var{name} @var{exp} @
9758 [#:guile (default-guile)] [#:module-path %load-path] @
9759 [#:system (%current-system)] [#:target #f]
9760 Return an executable script @var{name} that runs @var{exp} using
9761 @var{guile}, with @var{exp}'s imported modules in its search path.
9762 Look up @var{exp}'s modules in @var{module-path}.
9764 The example below builds a script that simply invokes the @command{ls}
9768 (use-modules (guix gexp) (gnu packages base))
9770 (gexp->script "list-files"
9771 #~(execl #$(file-append coreutils "/bin/ls")
9775 When ``running'' it through the store (@pxref{The Store Monad,
9776 @code{run-with-store}}), we obtain a derivation that produces an
9777 executable file @file{/gnu/store/@dots{}-list-files} along these lines:
9780 #!/gnu/store/@dots{}-guile-2.0.11/bin/guile -ds
9782 (execl "/gnu/store/@dots{}-coreutils-8.22"/bin/ls" "ls")
9786 @deffn {Scheme Procedure} program-file @var{name} @var{exp} @
9787 [#:guile #f] [#:module-path %load-path]
9788 Return an object representing the executable store item @var{name} that
9789 runs @var{gexp}. @var{guile} is the Guile package used to execute that
9790 script. Imported modules of @var{gexp} are looked up in @var{module-path}.
9792 This is the declarative counterpart of @code{gexp->script}.
9795 @deffn {Monadic Procedure} gexp->file @var{name} @var{exp} @
9796 [#:set-load-path? #t] [#:module-path %load-path] @
9798 [#:guile (default-guile)]
9799 Return a derivation that builds a file @var{name} containing @var{exp}.
9800 When @var{splice?} is true, @var{exp} is considered to be a list of
9801 expressions that will be spliced in the resulting file.
9803 When @var{set-load-path?} is true, emit code in the resulting file to
9804 set @code{%load-path} and @code{%load-compiled-path} to honor
9805 @var{exp}'s imported modules. Look up @var{exp}'s modules in
9808 The resulting file holds references to all the dependencies of @var{exp}
9809 or a subset thereof.
9812 @deffn {Scheme Procedure} scheme-file @var{name} @var{exp} @
9813 [#:splice? #f] [#:set-load-path? #t]
9814 Return an object representing the Scheme file @var{name} that contains
9817 This is the declarative counterpart of @code{gexp->file}.
9820 @deffn {Monadic Procedure} text-file* @var{name} @var{text} @dots{}
9821 Return as a monadic value a derivation that builds a text file
9822 containing all of @var{text}. @var{text} may list, in addition to
9823 strings, objects of any type that can be used in a gexp: packages,
9824 derivations, local file objects, etc. The resulting store file holds
9825 references to all these.
9827 This variant should be preferred over @code{text-file} anytime the file
9828 to create will reference items from the store. This is typically the
9829 case when building a configuration file that embeds store file names,
9833 (define (profile.sh)
9834 ;; Return the name of a shell script in the store that
9835 ;; initializes the 'PATH' environment variable.
9836 (text-file* "profile.sh"
9837 "export PATH=" coreutils "/bin:"
9838 grep "/bin:" sed "/bin\n"))
9841 In this example, the resulting @file{/gnu/store/@dots{}-profile.sh} file
9842 will reference @var{coreutils}, @var{grep}, and @var{sed}, thereby
9843 preventing them from being garbage-collected during its lifetime.
9846 @deffn {Scheme Procedure} mixed-text-file @var{name} @var{text} @dots{}
9847 Return an object representing store file @var{name} containing
9848 @var{text}. @var{text} is a sequence of strings and file-like objects,
9852 (mixed-text-file "profile"
9853 "export PATH=" coreutils "/bin:" grep "/bin")
9856 This is the declarative counterpart of @code{text-file*}.
9859 @deffn {Scheme Procedure} file-union @var{name} @var{files}
9860 Return a @code{<computed-file>} that builds a directory containing all of @var{files}.
9861 Each item in @var{files} must be a two-element list where the first element is the
9862 file name to use in the new directory, and the second element is a gexp
9863 denoting the target file. Here's an example:
9867 `(("hosts" ,(plain-file "hosts"
9868 "127.0.0.1 localhost"))
9869 ("bashrc" ,(plain-file "bashrc"
9870 "alias ls='ls --color=auto'"))))
9873 This yields an @code{etc} directory containing these two files.
9876 @deffn {Scheme Procedure} directory-union @var{name} @var{things}
9877 Return a directory that is the union of @var{things}, where @var{things} is a list of
9878 file-like objects denoting directories. For example:
9881 (directory-union "guile+emacs" (list guile emacs))
9884 yields a directory that is the union of the @code{guile} and @code{emacs} packages.
9887 @deffn {Scheme Procedure} file-append @var{obj} @var{suffix} @dots{}
9888 Return a file-like object that expands to the concatenation of @var{obj}
9889 and @var{suffix}, where @var{obj} is a lowerable object and each
9890 @var{suffix} is a string.
9892 As an example, consider this gexp:
9895 (gexp->script "run-uname"
9896 #~(system* #$(file-append coreutils
9900 The same effect could be achieved with:
9903 (gexp->script "run-uname"
9904 #~(system* (string-append #$coreutils
9908 There is one difference though: in the @code{file-append} case, the
9909 resulting script contains the absolute file name as a string, whereas in
9910 the second case, the resulting script contains a @code{(string-append
9911 @dots{})} expression to construct the file name @emph{at run time}.
9914 @deffn {Scheme Syntax} let-system @var{system} @var{body}@dots{}
9915 @deffnx {Scheme Syntax} let-system (@var{system} @var{target}) @var{body}@dots{}
9916 Bind @var{system} to the currently targeted system---e.g.,
9917 @code{"x86_64-linux"}---within @var{body}.
9919 In the second case, additionally bind @var{target} to the current
9920 cross-compilation target---a GNU triplet such as
9921 @code{"arm-linux-gnueabihf"}---or @code{#f} if we are not
9924 @code{let-system} is useful in the occasional case where the object
9925 spliced into the gexp depends on the target system, as in this example:
9929 #+(let-system system
9930 (cond ((string-prefix? "armhf-" system)
9931 (file-append qemu "/bin/qemu-system-arm"))
9932 ((string-prefix? "x86_64-" system)
9933 (file-append qemu "/bin/qemu-system-x86_64"))
9936 "-net" "user" #$image)
9940 @deffn {Scheme Syntax} with-parameters ((@var{parameter} @var{value}) @dots{}) @var{exp}
9941 This macro is similar to the @code{parameterize} form for
9942 dynamically-bound @dfn{parameters} (@pxref{Parameters,,, guile, GNU
9943 Guile Reference Manual}). The key difference is that it takes effect
9944 when the file-like object returned by @var{exp} is lowered to a
9945 derivation or store item.
9947 A typical use of @code{with-parameters} is to force the system in effect
9951 (with-parameters ((%current-system "i686-linux"))
9955 The example above returns an object that corresponds to the i686 build
9956 of Coreutils, regardless of the current value of @code{%current-system}.
9960 Of course, in addition to gexps embedded in ``host'' code, there are
9961 also modules containing build tools. To make it clear that they are
9962 meant to be used in the build stratum, these modules are kept in the
9963 @code{(guix build @dots{})} name space.
9965 @cindex lowering, of high-level objects in gexps
9966 Internally, high-level objects are @dfn{lowered}, using their compiler,
9967 to either derivations or store items. For instance, lowering a package
9968 yields a derivation, and lowering a @code{plain-file} yields a store
9969 item. This is achieved using the @code{lower-object} monadic procedure.
9971 @deffn {Monadic Procedure} lower-object @var{obj} [@var{system}] @
9973 Return as a value in @code{%store-monad} the derivation or store item
9974 corresponding to @var{obj} for @var{system}, cross-compiling for
9975 @var{target} if @var{target} is true. @var{obj} must be an object that
9976 has an associated gexp compiler, such as a @code{<package>}.
9979 @node Invoking guix repl
9980 @section Invoking @command{guix repl}
9982 @cindex REPL, read-eval-print loop, script
9983 The @command{guix repl} command makes it easier to program Guix in Guile
9984 by launching a Guile @dfn{read-eval-print loop} (REPL) for interactive
9985 programming (@pxref{Using Guile Interactively,,, guile,
9986 GNU Guile Reference Manual}), or by running Guile scripts
9987 (@pxref{Running Guile Scripts,,, guile,
9988 GNU Guile Reference Manual}).
9989 Compared to just launching the @command{guile}
9990 command, @command{guix repl} guarantees that all the Guix modules and all its
9991 dependencies are available in the search path.
9993 The general syntax is:
9996 guix repl @var{options} [@var{file} @var{args}]
9999 When a @var{file} argument is provided, @var{file} is
10000 executed as a Guile scripts:
10003 guix repl my-script.scm
10006 To pass arguments to the script, use @code{--} to prevent them from
10007 being interpreted as arguments to @command{guix repl} itself:
10010 guix repl -- my-script.scm --input=foo.txt
10013 To make a script executable directly from the shell, using the guix
10014 executable that is on the user's search path, add the following two
10015 lines at the top of the script:
10018 @code{#!/usr/bin/env -S guix repl --}
10022 Without a file name argument, a Guile REPL is started:
10026 scheme@@(guile-user)> ,use (gnu packages base)
10027 scheme@@(guile-user)> coreutils
10028 $1 = #<package coreutils@@8.29 gnu/packages/base.scm:327 3e28300>
10032 In addition, @command{guix repl} implements a simple machine-readable REPL
10033 protocol for use by @code{(guix inferior)}, a facility to interact with
10034 @dfn{inferiors}, separate processes running a potentially different revision
10037 The available options are as follows:
10040 @item --type=@var{type}
10041 @itemx -t @var{type}
10042 Start a REPL of the given @var{TYPE}, which can be one of the following:
10046 This is default, and it spawns a standard full-featured Guile REPL.
10048 Spawn a REPL that uses the machine-readable protocol. This is the protocol
10049 that the @code{(guix inferior)} module speaks.
10052 @item --listen=@var{endpoint}
10053 By default, @command{guix repl} reads from standard input and writes to
10054 standard output. When this option is passed, it will instead listen for
10055 connections on @var{endpoint}. Here are examples of valid options:
10058 @item --listen=tcp:37146
10059 Accept connections on localhost on port 37146.
10061 @item --listen=unix:/tmp/socket
10062 Accept connections on the Unix-domain socket @file{/tmp/socket}.
10065 @item --load-path=@var{directory}
10066 @itemx -L @var{directory}
10067 Add @var{directory} to the front of the package module search path
10068 (@pxref{Package Modules}).
10070 This allows users to define their own packages and make them visible to
10071 the script or REPL.
10074 Inhibit loading of the @file{~/.guile} file. By default, that
10075 configuration file is loaded when spawning a @code{guile} REPL.
10078 @c *********************************************************************
10082 This section describes Guix command-line utilities. Some of them are
10083 primarily targeted at developers and users who write new package
10084 definitions, while others are more generally useful. They complement
10085 the Scheme programming interface of Guix in a convenient way.
10088 * Invoking guix build:: Building packages from the command line.
10089 * Invoking guix edit:: Editing package definitions.
10090 * Invoking guix download:: Downloading a file and printing its hash.
10091 * Invoking guix hash:: Computing the cryptographic hash of a file.
10092 * Invoking guix import:: Importing package definitions.
10093 * Invoking guix refresh:: Updating package definitions.
10094 * Invoking guix lint:: Finding errors in package definitions.
10095 * Invoking guix size:: Profiling disk usage.
10096 * Invoking guix graph:: Visualizing the graph of packages.
10097 * Invoking guix publish:: Sharing substitutes.
10098 * Invoking guix challenge:: Challenging substitute servers.
10099 * Invoking guix copy:: Copying to and from a remote store.
10100 * Invoking guix container:: Process isolation.
10101 * Invoking guix weather:: Assessing substitute availability.
10102 * Invoking guix processes:: Listing client processes.
10105 @node Invoking guix build
10106 @section Invoking @command{guix build}
10108 @cindex package building
10109 @cindex @command{guix build}
10110 The @command{guix build} command builds packages or derivations and
10111 their dependencies, and prints the resulting store paths. Note that it
10112 does not modify the user's profile---this is the job of the
10113 @command{guix package} command (@pxref{Invoking guix package}). Thus,
10114 it is mainly useful for distribution developers.
10116 The general syntax is:
10119 guix build @var{options} @var{package-or-derivation}@dots{}
10122 As an example, the following command builds the latest versions of Emacs
10123 and of Guile, displays their build logs, and finally displays the
10124 resulting directories:
10127 guix build emacs guile
10130 Similarly, the following command builds all the available packages:
10133 guix build --quiet --keep-going \
10134 $(guix package -A | cut -f1,2 --output-delimiter=@@)
10137 @var{package-or-derivation} may be either the name of a package found in
10138 the software distribution such as @code{coreutils} or
10139 @code{coreutils@@8.20}, or a derivation such as
10140 @file{/gnu/store/@dots{}-coreutils-8.19.drv}. In the former case, a
10141 package with the corresponding name (and optionally version) is searched
10142 for among the GNU distribution modules (@pxref{Package Modules}).
10144 Alternatively, the @option{--expression} option may be used to specify a
10145 Scheme expression that evaluates to a package; this is useful when
10146 disambiguating among several same-named packages or package variants is
10149 There may be zero or more @var{options}. The available options are
10150 described in the subsections below.
10153 * Common Build Options:: Build options for most commands.
10154 * Package Transformation Options:: Creating variants of packages.
10155 * Additional Build Options:: Options specific to 'guix build'.
10156 * Debugging Build Failures:: Real life packaging experience.
10159 @node Common Build Options
10160 @subsection Common Build Options
10162 A number of options that control the build process are common to
10163 @command{guix build} and other commands that can spawn builds, such as
10164 @command{guix package} or @command{guix archive}. These are the
10169 @item --load-path=@var{directory}
10170 @itemx -L @var{directory}
10171 Add @var{directory} to the front of the package module search path
10172 (@pxref{Package Modules}).
10174 This allows users to define their own packages and make them visible to
10175 the command-line tools.
10177 @item --keep-failed
10179 Keep the build tree of failed builds. Thus, if a build fails, its build
10180 tree is kept under @file{/tmp}, in a directory whose name is shown at
10181 the end of the build log. This is useful when debugging build issues.
10182 @xref{Debugging Build Failures}, for tips and tricks on how to debug
10185 This option implies @option{--no-offload}, and it has no effect when
10186 connecting to a remote daemon with a @code{guix://} URI (@pxref{The
10187 Store, the @env{GUIX_DAEMON_SOCKET} variable}).
10191 Keep going when some of the derivations fail to build; return only once
10192 all the builds have either completed or failed.
10194 The default behavior is to stop as soon as one of the specified
10195 derivations has failed.
10199 Do not build the derivations.
10201 @anchor{fallback-option}
10203 When substituting a pre-built binary fails, fall back to building
10204 packages locally (@pxref{Substitution Failure}).
10206 @item --substitute-urls=@var{urls}
10207 @anchor{client-substitute-urls}
10208 Consider @var{urls} the whitespace-separated list of substitute source
10209 URLs, overriding the default list of URLs of @command{guix-daemon}
10210 (@pxref{daemon-substitute-urls,, @command{guix-daemon} URLs}).
10212 This means that substitutes may be downloaded from @var{urls}, provided
10213 they are signed by a key authorized by the system administrator
10214 (@pxref{Substitutes}).
10216 When @var{urls} is the empty string, substitutes are effectively
10219 @item --no-substitutes
10220 Do not use substitutes for build products. That is, always build things
10221 locally instead of allowing downloads of pre-built binaries
10222 (@pxref{Substitutes}).
10225 Do not ``graft'' packages. In practice, this means that package updates
10226 available as grafts are not applied. @xref{Security Updates}, for more
10227 information on grafts.
10229 @item --rounds=@var{n}
10230 Build each derivation @var{n} times in a row, and raise an error if
10231 consecutive build results are not bit-for-bit identical.
10233 This is a useful way to detect non-deterministic builds processes.
10234 Non-deterministic build processes are a problem because they make it
10235 practically impossible for users to @emph{verify} whether third-party
10236 binaries are genuine. @xref{Invoking guix challenge}, for more.
10238 When used in conjunction with @option{--keep-failed}, the differing
10239 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10240 This makes it easy to look for differences between the two results.
10243 Do not use offload builds to other machines (@pxref{Daemon Offload
10244 Setup}). That is, always build things locally instead of offloading
10245 builds to remote machines.
10247 @item --max-silent-time=@var{seconds}
10248 When the build or substitution process remains silent for more than
10249 @var{seconds}, terminate it and report a build failure.
10251 By default, the daemon's setting is honored (@pxref{Invoking
10252 guix-daemon, @option{--max-silent-time}}).
10254 @item --timeout=@var{seconds}
10255 Likewise, when the build or substitution process lasts for more than
10256 @var{seconds}, terminate it and report a build failure.
10258 By default, the daemon's setting is honored (@pxref{Invoking
10259 guix-daemon, @option{--timeout}}).
10261 @c Note: This option is actually not part of %standard-build-options but
10262 @c most programs honor it.
10263 @cindex verbosity, of the command-line tools
10264 @cindex build logs, verbosity
10265 @item -v @var{level}
10266 @itemx --verbosity=@var{level}
10267 Use the given verbosity @var{level}, an integer. Choosing 0 means that
10268 no output is produced, 1 is for quiet output; 2 is similar to 1 but it
10269 additionally displays download URLs; 3 shows all the build log output on
10272 @item --cores=@var{n}
10274 Allow the use of up to @var{n} CPU cores for the build. The special
10275 value @code{0} means to use as many CPU cores as available.
10277 @item --max-jobs=@var{n}
10279 Allow at most @var{n} build jobs in parallel. @xref{Invoking
10280 guix-daemon, @option{--max-jobs}}, for details about this option and the
10281 equivalent @command{guix-daemon} option.
10283 @item --debug=@var{level}
10284 Produce debugging output coming from the build daemon. @var{level} must be an
10285 integer between 0 and 5; higher means more verbose output. Setting a level of
10286 4 or more may be helpful when debugging setup issues with the build daemon.
10290 Behind the scenes, @command{guix build} is essentially an interface to
10291 the @code{package-derivation} procedure of the @code{(guix packages)}
10292 module, and to the @code{build-derivations} procedure of the @code{(guix
10293 derivations)} module.
10295 In addition to options explicitly passed on the command line,
10296 @command{guix build} and other @command{guix} commands that support
10297 building honor the @env{GUIX_BUILD_OPTIONS} environment variable.
10299 @defvr {Environment Variable} GUIX_BUILD_OPTIONS
10300 Users can define this variable to a list of command line options that
10301 will automatically be used by @command{guix build} and other
10302 @command{guix} commands that can perform builds, as in the example
10306 $ export GUIX_BUILD_OPTIONS="--no-substitutes -c 2 -L /foo/bar"
10309 These options are parsed independently, and the result is appended to
10310 the parsed command-line options.
10314 @node Package Transformation Options
10315 @subsection Package Transformation Options
10317 @cindex package variants
10318 Another set of command-line options supported by @command{guix build}
10319 and also @command{guix package} are @dfn{package transformation
10320 options}. These are options that make it possible to define @dfn{package
10321 variants}---for instance, packages built from different source code.
10322 This is a convenient way to create customized packages on the fly
10323 without having to type in the definitions of package variants
10324 (@pxref{Defining Packages}).
10326 Package transformation options are preserved across upgrades:
10327 @command{guix upgrade} attempts to apply transformation options
10328 initially used when creating the profile to the upgraded packages.
10330 The available options are listed below. Most commands support them and
10331 also support a @option{--help-transform} option that lists all the
10332 available options and a synopsis (these options are not shown in the
10333 @option{--help} output for brevity).
10337 @item --with-source=@var{source}
10338 @itemx --with-source=@var{package}=@var{source}
10339 @itemx --with-source=@var{package}@@@var{version}=@var{source}
10340 Use @var{source} as the source of @var{package}, and @var{version} as
10341 its version number.
10342 @var{source} must be a file name or a URL, as for @command{guix
10343 download} (@pxref{Invoking guix download}).
10345 When @var{package} is omitted,
10346 it is taken to be the package name specified on the
10347 command line that matches the base of @var{source}---e.g.,
10348 if @var{source} is @code{/src/guile-2.0.10.tar.gz}, the corresponding
10349 package is @code{guile}.
10351 Likewise, when @var{version} is omitted, the version string is inferred from
10352 @var{source}; in the previous example, it is @code{2.0.10}.
10354 This option allows users to try out versions of packages other than the
10355 one provided by the distribution. The example below downloads
10356 @file{ed-1.7.tar.gz} from a GNU mirror and uses that as the source for
10357 the @code{ed} package:
10360 guix build ed --with-source=mirror://gnu/ed/ed-1.7.tar.gz
10363 As a developer, @option{--with-source} makes it easy to test release
10367 guix build guile --with-source=../guile-2.0.9.219-e1bb7.tar.xz
10370 @dots{} or to build from a checkout in a pristine environment:
10373 $ git clone git://git.sv.gnu.org/guix.git
10374 $ guix build guix --with-source=guix@@1.0=./guix
10377 @item --with-input=@var{package}=@var{replacement}
10378 Replace dependency on @var{package} by a dependency on
10379 @var{replacement}. @var{package} must be a package name, and
10380 @var{replacement} must be a package specification such as @code{guile}
10381 or @code{guile@@1.8}.
10383 For instance, the following command builds Guix, but replaces its
10384 dependency on the current stable version of Guile with a dependency on
10385 the legacy version of Guile, @code{guile@@2.0}:
10388 guix build --with-input=guile=guile@@2.0 guix
10391 This is a recursive, deep replacement. So in this example, both
10392 @code{guix} and its dependency @code{guile-json} (which also depends on
10393 @code{guile}) get rebuilt against @code{guile@@2.0}.
10395 This is implemented using the @code{package-input-rewriting} Scheme
10396 procedure (@pxref{Defining Packages, @code{package-input-rewriting}}).
10398 @item --with-graft=@var{package}=@var{replacement}
10399 This is similar to @option{--with-input} but with an important difference:
10400 instead of rebuilding the whole dependency chain, @var{replacement} is
10401 built and then @dfn{grafted} onto the binaries that were initially
10402 referring to @var{package}. @xref{Security Updates}, for more
10403 information on grafts.
10405 For example, the command below grafts version 3.5.4 of GnuTLS onto Wget
10406 and all its dependencies, replacing references to the version of GnuTLS
10407 they currently refer to:
10410 guix build --with-graft=gnutls=gnutls@@3.5.4 wget
10413 This has the advantage of being much faster than rebuilding everything.
10414 But there is a caveat: it works if and only if @var{package} and
10415 @var{replacement} are strictly compatible---for example, if they provide
10416 a library, the application binary interface (ABI) of those libraries
10417 must be compatible. If @var{replacement} is somehow incompatible with
10418 @var{package}, then the resulting package may be unusable. Use with
10421 @cindex debugging info, rebuilding
10422 @item --with-debug-info=@var{package}
10423 Build @var{package} in a way that preserves its debugging info and graft
10424 it onto packages that depend on it. This is useful if @var{package}
10425 does not already provide debugging info as a @code{debug} output
10426 (@pxref{Installing Debugging Files}).
10428 For example, suppose you're experiencing a crash in Inkscape and would
10429 like to see what's up in GLib, a library deep down in Inkscape's
10430 dependency graph. GLib lacks a @code{debug} output, so debugging is
10431 tough. Fortunately, you rebuild GLib with debugging info and tack it on
10435 guix install inkscape --with-debug-info=glib
10438 Only GLib needs to be recompiled so this takes a reasonable amount of
10439 time. @xref{Installing Debugging Files}, for more info.
10442 Under the hood, this option works by passing the @samp{#:strip-binaries?
10443 #f} to the build system of the package of interest (@pxref{Build
10444 Systems}). Most build systems support that option but some do not. In
10445 that case, an error is raised.
10447 Likewise, if a C/C++ package is built without @code{-g} (which is rarely
10448 the case), debugging info will remain unavailable even when
10449 @code{#:strip-binaries?} is false.
10452 @cindex tool chain, changing the build tool chain of a package
10453 @item --with-c-toolchain=@var{package}=@var{toolchain}
10454 This option changes the compilation of @var{package} and everything that
10455 depends on it so that they get built with @var{toolchain} instead of the
10456 default GNU tool chain for C/C++.
10458 Consider this example:
10461 guix build octave-cli \
10462 --with-c-toolchain=fftw=gcc-toolchain@@10 \
10463 --with-c-toolchain=fftwf=gcc-toolchain@@10
10466 The command above builds a variant of the @code{fftw} and @code{fftwf}
10467 packages using version 10 of @code{gcc-toolchain} instead of the default
10468 tool chain, and then builds a variant of the GNU@tie{}Octave
10469 command-line interface using them. GNU@tie{}Octave itself is also built
10470 with @code{gcc-toolchain@@10}.
10472 This other example builds the Hardware Locality (@code{hwloc}) library
10473 and its dependents up to @code{intel-mpi-benchmarks} with the Clang C
10477 guix build --with-c-toolchain=hwloc=clang-toolchain \
10478 intel-mpi-benchmarks
10482 There can be application binary interface (ABI) incompatibilities among
10483 tool chains. This is particularly true of the C++ standard library and
10484 run-time support libraries such as that of OpenMP@. By rebuilding all
10485 dependents with the same tool chain, @option{--with-c-toolchain} minimizes
10486 the risks of incompatibility but cannot entirely eliminate them. Choose
10487 @var{package} wisely.
10490 @item --with-git-url=@var{package}=@var{url}
10491 @cindex Git, using the latest commit
10492 @cindex latest commit, building
10493 Build @var{package} from the latest commit of the @code{master} branch of the
10494 Git repository at @var{url}. Git sub-modules of the repository are fetched,
10497 For example, the following command builds the NumPy Python library against the
10498 latest commit of the master branch of Python itself:
10501 guix build python-numpy \
10502 --with-git-url=python=https://github.com/python/cpython
10505 This option can also be combined with @option{--with-branch} or
10506 @option{--with-commit} (see below).
10508 @cindex continuous integration
10509 Obviously, since it uses the latest commit of the given branch, the result of
10510 such a command varies over time. Nevertheless it is a convenient way to
10511 rebuild entire software stacks against the latest commit of one or more
10512 packages. This is particularly useful in the context of continuous
10515 Checkouts are kept in a cache under @file{~/.cache/guix/checkouts} to speed up
10516 consecutive accesses to the same repository. You may want to clean it up once
10517 in a while to save disk space.
10519 @item --with-branch=@var{package}=@var{branch}
10520 Build @var{package} from the latest commit of @var{branch}. If the
10521 @code{source} field of @var{package} is an origin with the @code{git-fetch}
10522 method (@pxref{origin Reference}) or a @code{git-checkout} object, the
10523 repository URL is taken from that @code{source}. Otherwise you have to use
10524 @option{--with-git-url} to specify the URL of the Git repository.
10526 For instance, the following command builds @code{guile-sqlite3} from the
10527 latest commit of its @code{master} branch, and then builds @code{guix} (which
10528 depends on it) and @code{cuirass} (which depends on @code{guix}) against this
10529 specific @code{guile-sqlite3} build:
10532 guix build --with-branch=guile-sqlite3=master cuirass
10535 @item --with-commit=@var{package}=@var{commit}
10536 This is similar to @option{--with-branch}, except that it builds from
10537 @var{commit} rather than the tip of a branch. @var{commit} must be a valid
10538 Git commit SHA1 identifier or a tag.
10540 @item --with-patch=@var{package}=@var{file}
10541 Add @var{file} to the list of patches applied to @var{package}, where
10542 @var{package} is a spec such as @code{python@@3.8} or @code{glibc}.
10543 @var{file} must contain a patch; it is applied with the flags specified
10544 in the @code{origin} of @var{package} (@pxref{origin Reference}), which
10545 by default includes @code{-p1} (@pxref{patch Directories,,, diffutils,
10546 Comparing and Merging Files}).
10548 As an example, the command below rebuilds Coreutils with the GNU C
10549 Library (glibc) patched with the given patch:
10552 guix build coreutils --with-patch=glibc=./glibc-frob.patch
10555 In this example, glibc itself as well as everything that leads to
10556 Coreutils in the dependency graph is rebuilt.
10558 @cindex upstream, latest version
10559 @item --with-latest=@var{package}
10560 So you like living on the bleeding edge? This option is for you! It
10561 replaces occurrences of @var{package} in the dependency graph with its
10562 latest upstream version, as reported by @command{guix refresh}
10563 (@pxref{Invoking guix refresh}).
10565 It does so by determining the latest upstream release of @var{package}
10566 (if possible), downloading it, and authenticating it @emph{if} it comes
10567 with an OpenPGP signature.
10569 As an example, the command below builds Guix against the latest version
10573 guix build guix --with-latest=guile-json
10576 There are limitations. First, in cases where the tool cannot or does
10577 not know how to authenticate source code, you are at risk of running
10578 malicious code; a warning is emitted in this case. Second, this option
10579 simply changes the source used in the existing package definitions,
10580 which is not always sufficient: there might be additional dependencies
10581 that need to be added, patches to apply, and more generally the quality
10582 assurance work that Guix developers normally do will be missing.
10584 You've been warned! In all the other cases, it's a snappy way to stay
10585 on top. We encourage you to submit patches updating the actual package
10586 definitions once you have successfully tested an upgrade
10587 (@pxref{Contributing}).
10589 @cindex test suite, skipping
10590 @item --without-tests=@var{package}
10591 Build @var{package} without running its tests. This can be useful in
10592 situations where you want to skip the lengthy test suite of a
10593 intermediate package, or if a package's test suite fails in a
10594 non-deterministic fashion. It should be used with care because running
10595 the test suite is a good way to ensure a package is working as intended.
10597 Turning off tests leads to a different store item. Consequently, when
10598 using this option, anything that depends on @var{package} must be
10599 rebuilt, as in this example:
10602 guix install --without-tests=python python-notebook
10605 The command above installs @code{python-notebook} on top of
10606 @code{python} built without running its test suite. To do so, it also
10607 rebuilds everything that depends on @code{python}, including
10608 @code{python-notebook} itself.
10610 Internally, @option{--without-tests} relies on changing the
10611 @code{#:tests?} option of a package's @code{check} phase (@pxref{Build
10612 Systems}). Note that some packages use a customized @code{check} phase
10613 that does not respect a @code{#:tests? #f} setting. Therefore,
10614 @option{--without-tests} has no effect on these packages.
10618 Wondering how to achieve the same effect using Scheme code, for example
10619 in your manifest, or how to write your own package transformation?
10620 @xref{Defining Package Variants}, for an overview of the programming
10621 interfaces available.
10623 @node Additional Build Options
10624 @subsection Additional Build Options
10626 The command-line options presented below are specific to @command{guix
10633 Build quietly, without displaying the build log; this is equivalent to
10634 @option{--verbosity=0}. Upon completion, the build log is kept in @file{/var}
10635 (or similar) and can always be retrieved using the @option{--log-file} option.
10637 @item --file=@var{file}
10638 @itemx -f @var{file}
10639 Build the package, derivation, or other file-like object that the code within
10640 @var{file} evaluates to (@pxref{G-Expressions, file-like objects}).
10642 As an example, @var{file} might contain a package definition like this
10643 (@pxref{Defining Packages}):
10646 @include package-hello.scm
10649 The @var{file} may also contain a JSON representation of one or more
10650 package definitions. Running @code{guix build -f} on @file{hello.json}
10651 with the following contents would result in building the packages
10652 @code{myhello} and @code{greeter}:
10655 @verbatiminclude package-hello.json
10658 @item --manifest=@var{manifest}
10659 @itemx -m @var{manifest}
10660 Build all packages listed in the given @var{manifest}
10661 (@pxref{profile-manifest, @option{--manifest}}).
10663 @item --expression=@var{expr}
10664 @itemx -e @var{expr}
10665 Build the package or derivation @var{expr} evaluates to.
10667 For example, @var{expr} may be @code{(@@ (gnu packages guile)
10668 guile-1.8)}, which unambiguously designates this specific variant of
10669 version 1.8 of Guile.
10671 Alternatively, @var{expr} may be a G-expression, in which case it is used
10672 as a build program passed to @code{gexp->derivation}
10673 (@pxref{G-Expressions}).
10675 Lastly, @var{expr} may refer to a zero-argument monadic procedure
10676 (@pxref{The Store Monad}). The procedure must return a derivation as a
10677 monadic value, which is then passed through @code{run-with-store}.
10681 Build the source derivations of the packages, rather than the packages
10684 For instance, @code{guix build -S gcc} returns something like
10685 @file{/gnu/store/@dots{}-gcc-4.7.2.tar.bz2}, which is the GCC
10688 The returned source tarball is the result of applying any patches and
10689 code snippets specified in the package @code{origin} (@pxref{Defining
10692 @cindex source, verification
10693 As with other derivations, the result of building a source derivation
10694 can be verified using the @option{--check} option (@pxref{build-check}).
10695 This is useful to validate that a (potentially already built or
10696 substituted, thus cached) package source matches against its declared
10699 Note that @command{guix build -S} compiles the sources only of the
10700 specified packages. They do not include the sources of statically
10701 linked dependencies and by themselves are insufficient for reproducing
10705 Fetch and return the source of @var{package-or-derivation} and all their
10706 dependencies, recursively. This is a handy way to obtain a local copy
10707 of all the source code needed to build @var{packages}, allowing you to
10708 eventually build them even without network access. It is an extension
10709 of the @option{--source} option and can accept one of the following
10710 optional argument values:
10714 This value causes the @option{--sources} option to behave in the same way
10715 as the @option{--source} option.
10718 Build the source derivations of all packages, including any source that
10719 might be listed as @code{inputs}. This is the default value.
10722 $ guix build --sources tzdata
10723 The following derivations will be built:
10724 /gnu/store/@dots{}-tzdata2015b.tar.gz.drv
10725 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10729 Build the source derivations of all packages, as well of all transitive
10730 inputs to the packages. This can be used e.g.@: to
10731 prefetch package source for later offline building.
10734 $ guix build --sources=transitive tzdata
10735 The following derivations will be built:
10736 /gnu/store/@dots{}-tzcode2015b.tar.gz.drv
10737 /gnu/store/@dots{}-findutils-4.4.2.tar.xz.drv
10738 /gnu/store/@dots{}-grep-2.21.tar.xz.drv
10739 /gnu/store/@dots{}-coreutils-8.23.tar.xz.drv
10740 /gnu/store/@dots{}-make-4.1.tar.xz.drv
10741 /gnu/store/@dots{}-bash-4.3.tar.xz.drv
10747 @item --system=@var{system}
10748 @itemx -s @var{system}
10749 Attempt to build for @var{system}---e.g., @code{i686-linux}---instead of
10750 the system type of the build host. The @command{guix build} command allows
10751 you to repeat this option several times, in which case it builds for all the
10752 specified systems; other commands ignore extraneous @option{-s} options.
10755 The @option{--system} flag is for @emph{native} compilation and must not
10756 be confused with cross-compilation. See @option{--target} below for
10757 information on cross-compilation.
10760 An example use of this is on Linux-based systems, which can emulate
10761 different personalities. For instance, passing
10762 @option{--system=i686-linux} on an @code{x86_64-linux} system or
10763 @option{--system=armhf-linux} on an @code{aarch64-linux} system allows
10764 you to build packages in a complete 32-bit environment.
10767 Building for an @code{armhf-linux} system is unconditionally enabled on
10768 @code{aarch64-linux} machines, although certain aarch64 chipsets do not
10769 allow for this functionality, notably the ThunderX.
10772 Similarly, when transparent emulation with QEMU and @code{binfmt_misc}
10773 is enabled (@pxref{Virtualization Services,
10774 @code{qemu-binfmt-service-type}}), you can build for any system for
10775 which a QEMU @code{binfmt_misc} handler is installed.
10777 Builds for a system other than that of the machine you are using can
10778 also be offloaded to a remote machine of the right architecture.
10779 @xref{Daemon Offload Setup}, for more information on offloading.
10781 @item --target=@var{triplet}
10782 @cindex cross-compilation
10783 Cross-build for @var{triplet}, which must be a valid GNU triplet, such
10784 as @code{"aarch64-linux-gnu"} (@pxref{Specifying Target Triplets, GNU
10785 configuration triplets,, autoconf, Autoconf}).
10787 @anchor{build-check}
10789 @cindex determinism, checking
10790 @cindex reproducibility, checking
10791 Rebuild @var{package-or-derivation}, which are already available in the
10792 store, and raise an error if the build results are not bit-for-bit
10795 This mechanism allows you to check whether previously installed
10796 substitutes are genuine (@pxref{Substitutes}), or whether the build result
10797 of a package is deterministic. @xref{Invoking guix challenge}, for more
10798 background information and tools.
10800 When used in conjunction with @option{--keep-failed}, the differing
10801 output is kept in the store, under @file{/gnu/store/@dots{}-check}.
10802 This makes it easy to look for differences between the two results.
10805 @cindex repairing store items
10806 @cindex corruption, recovering from
10807 Attempt to repair the specified store items, if they are corrupt, by
10808 re-downloading or rebuilding them.
10810 This operation is not atomic and thus restricted to @code{root}.
10812 @item --derivations
10814 Return the derivation paths, not the output paths, of the given
10817 @item --root=@var{file}
10818 @itemx -r @var{file}
10819 @cindex GC roots, adding
10820 @cindex garbage collector roots, adding
10821 Make @var{file} a symlink to the result, and register it as a garbage
10824 Consequently, the results of this @command{guix build} invocation are
10825 protected from garbage collection until @var{file} is removed. When
10826 that option is omitted, build results are eligible for garbage
10827 collection as soon as the build completes. @xref{Invoking guix gc}, for
10831 @cindex build logs, access
10832 Return the build log file names or URLs for the given
10833 @var{package-or-derivation}, or raise an error if build logs are
10836 This works regardless of how packages or derivations are specified. For
10837 instance, the following invocations are equivalent:
10840 guix build --log-file $(guix build -d guile)
10841 guix build --log-file $(guix build guile)
10842 guix build --log-file guile
10843 guix build --log-file -e '(@@ (gnu packages guile) guile-2.0)'
10846 If a log is unavailable locally, and unless @option{--no-substitutes} is
10847 passed, the command looks for a corresponding log on one of the
10848 substitute servers (as specified with @option{--substitute-urls}).
10850 So for instance, imagine you want to see the build log of GDB on MIPS,
10851 but you are actually on an @code{x86_64} machine:
10854 $ guix build --log-file gdb -s aarch64-linux
10855 https://@value{SUBSTITUTE-SERVER}/log/@dots{}-gdb-7.10
10858 You can freely access a huge library of build logs!
10861 @node Debugging Build Failures
10862 @subsection Debugging Build Failures
10864 @cindex build failures, debugging
10865 When defining a new package (@pxref{Defining Packages}), you will
10866 probably find yourself spending some time debugging and tweaking the
10867 build until it succeeds. To do that, you need to operate the build
10868 commands yourself in an environment as close as possible to the one the
10871 To that end, the first thing to do is to use the @option{--keep-failed}
10872 or @option{-K} option of @command{guix build}, which will keep the
10873 failed build tree in @file{/tmp} or whatever directory you specified as
10874 @env{TMPDIR} (@pxref{Common Build Options, @option{--keep-failed}}).
10876 From there on, you can @command{cd} to the failed build tree and source
10877 the @file{environment-variables} file, which contains all the
10878 environment variable definitions that were in place when the build
10879 failed. So let's say you're debugging a build failure in package
10880 @code{foo}; a typical session would look like this:
10883 $ guix build foo -K
10884 @dots{} @i{build fails}
10885 $ cd /tmp/guix-build-foo.drv-0
10886 $ source ./environment-variables
10890 Now, you can invoke commands as if you were the daemon (almost) and
10891 troubleshoot your build process.
10893 Sometimes it happens that, for example, a package's tests pass when you
10894 run them manually but they fail when the daemon runs them. This can
10895 happen because the daemon runs builds in containers where, unlike in our
10896 environment above, network access is missing, @file{/bin/sh} does not
10897 exist, etc. (@pxref{Build Environment Setup}).
10899 In such cases, you may need to run inspect the build process from within
10900 a container similar to the one the build daemon creates:
10903 $ guix build -K foo
10905 $ cd /tmp/guix-build-foo.drv-0
10906 $ guix environment --no-grafts -C foo --ad-hoc strace gdb
10907 [env]# source ./environment-variables
10911 Here, @command{guix environment -C} creates a container and spawns a new
10912 shell in it (@pxref{Invoking guix environment}). The @command{--ad-hoc
10913 strace gdb} part adds the @command{strace} and @command{gdb} commands to
10914 the container, which you may find handy while debugging. The
10915 @option{--no-grafts} option makes sure we get the exact same
10916 environment, with ungrafted packages (@pxref{Security Updates}, for more
10919 To get closer to a container like that used by the build daemon, we can
10920 remove @file{/bin/sh}:
10926 (Don't worry, this is harmless: this is all happening in the throw-away
10927 container created by @command{guix environment}.)
10929 The @command{strace} command is probably not in the search path, but we
10933 [env]# $GUIX_ENVIRONMENT/bin/strace -f -o log make check
10936 In this way, not only you will have reproduced the environment variables
10937 the daemon uses, you will also be running the build process in a container
10938 similar to the one the daemon uses.
10941 @node Invoking guix edit
10942 @section Invoking @command{guix edit}
10944 @cindex @command{guix edit}
10945 @cindex package definition, editing
10946 So many packages, so many source files! The @command{guix edit} command
10947 facilitates the life of users and packagers by pointing their editor at
10948 the source file containing the definition of the specified packages.
10952 guix edit gcc@@4.9 vim
10956 launches the program specified in the @env{VISUAL} or in the
10957 @env{EDITOR} environment variable to view the recipe of GCC@tie{}4.9.3
10960 If you are using a Guix Git checkout (@pxref{Building from Git}), or
10961 have created your own packages on @env{GUIX_PACKAGE_PATH}
10962 (@pxref{Package Modules}), you will be able to edit the package
10963 recipes. In other cases, you will be able to examine the read-only recipes
10964 for packages currently in the store.
10966 Instead of @env{GUIX_PACKAGE_PATH}, the command-line option
10967 @option{--load-path=@var{directory}} (or in short @option{-L
10968 @var{directory}}) allows you to add @var{directory} to the front of the
10969 package module search path and so make your own packages visible.
10971 @node Invoking guix download
10972 @section Invoking @command{guix download}
10974 @cindex @command{guix download}
10975 @cindex downloading package sources
10976 When writing a package definition, developers typically need to download
10977 a source tarball, compute its SHA256 hash, and write that
10978 hash in the package definition (@pxref{Defining Packages}). The
10979 @command{guix download} tool helps with this task: it downloads a file
10980 from the given URI, adds it to the store, and prints both its file name
10981 in the store and its SHA256 hash.
10983 The fact that the downloaded file is added to the store saves bandwidth:
10984 when the developer eventually tries to build the newly defined package
10985 with @command{guix build}, the source tarball will not have to be
10986 downloaded again because it is already in the store. It is also a
10987 convenient way to temporarily stash files, which may be deleted
10988 eventually (@pxref{Invoking guix gc}).
10990 The @command{guix download} command supports the same URIs as used in
10991 package definitions. In particular, it supports @code{mirror://} URIs.
10992 @code{https} URIs (HTTP over TLS) are supported @emph{provided} the
10993 Guile bindings for GnuTLS are available in the user's environment; when
10994 they are not available, an error is raised. @xref{Guile Preparations,
10995 how to install the GnuTLS bindings for Guile,, gnutls-guile,
10996 GnuTLS-Guile}, for more information.
10998 @command{guix download} verifies HTTPS server certificates by loading
10999 the certificates of X.509 authorities from the directory pointed to by
11000 the @env{SSL_CERT_DIR} environment variable (@pxref{X.509
11001 Certificates}), unless @option{--no-check-certificate} is used.
11003 The following options are available:
11006 @item --hash=@var{algorithm}
11007 @itemx -H @var{algorithm}
11008 Compute a hash using the specified @var{algorithm}. @xref{Invoking guix
11009 hash}, for more information.
11011 @item --format=@var{fmt}
11012 @itemx -f @var{fmt}
11013 Write the hash in the format specified by @var{fmt}. For more
11014 information on the valid values for @var{fmt}, @pxref{Invoking guix hash}.
11016 @item --no-check-certificate
11017 Do not validate the X.509 certificates of HTTPS servers.
11019 When using this option, you have @emph{absolutely no guarantee} that you
11020 are communicating with the authentic server responsible for the given
11021 URL, which makes you vulnerable to ``man-in-the-middle'' attacks.
11023 @item --output=@var{file}
11024 @itemx -o @var{file}
11025 Save the downloaded file to @var{file} instead of adding it to the
11029 @node Invoking guix hash
11030 @section Invoking @command{guix hash}
11032 @cindex @command{guix hash}
11033 The @command{guix hash} command computes the hash of a file.
11034 It is primarily a convenience tool for anyone contributing to the
11035 distribution: it computes the cryptographic hash of a file, which can be
11036 used in the definition of a package (@pxref{Defining Packages}).
11038 The general syntax is:
11041 guix hash @var{option} @var{file}
11044 When @var{file} is @code{-} (a hyphen), @command{guix hash} computes the
11045 hash of data read from standard input. @command{guix hash} has the
11050 @item --hash=@var{algorithm}
11051 @itemx -H @var{algorithm}
11052 Compute a hash using the specified @var{algorithm}, @code{sha256} by
11055 @var{algorithm} must the name of a cryptographic hash algorithm
11056 supported by Libgcrypt @i{via} Guile-Gcrypt---e.g., @code{sha512} or
11057 @code{sha3-256} (@pxref{Hash Functions,,, guile-gcrypt, Guile-Gcrypt
11058 Reference Manual}).
11060 @item --format=@var{fmt}
11061 @itemx -f @var{fmt}
11062 Write the hash in the format specified by @var{fmt}.
11064 Supported formats: @code{base64}, @code{nix-base32}, @code{base32}, @code{base16}
11065 (@code{hex} and @code{hexadecimal} can be used as well).
11067 If the @option{--format} option is not specified, @command{guix hash}
11068 will output the hash in @code{nix-base32}. This representation is used
11069 in the definitions of packages.
11073 Compute the hash on @var{file} recursively.
11075 In this case, the hash is computed on an archive containing @var{file},
11076 including its children if it is a directory. Some of the metadata of
11077 @var{file} is part of the archive; for instance, when @var{file} is a
11078 regular file, the hash is different depending on whether @var{file} is
11079 executable or not. Metadata such as time stamps has no impact on the
11080 hash (@pxref{Invoking guix archive}).
11081 @c FIXME: Replace xref above with xref to an ``Archive'' section when
11084 @item --exclude-vcs
11086 When combined with @option{--recursive}, exclude version control system
11087 directories (@file{.bzr}, @file{.git}, @file{.hg}, etc.).
11090 As an example, here is how you would compute the hash of a Git checkout,
11091 which is useful when using the @code{git-fetch} method (@pxref{origin
11095 $ git clone http://example.org/foo.git
11101 @node Invoking guix import
11102 @section Invoking @command{guix import}
11104 @cindex importing packages
11105 @cindex package import
11106 @cindex package conversion
11107 @cindex Invoking @command{guix import}
11108 The @command{guix import} command is useful for people who would like to
11109 add a package to the distribution with as little work as
11110 possible---a legitimate demand. The command knows of a few
11111 repositories from which it can ``import'' package metadata. The result
11112 is a package definition, or a template thereof, in the format we know
11113 (@pxref{Defining Packages}).
11115 The general syntax is:
11118 guix import @var{importer} @var{options}@dots{}
11121 @var{importer} specifies the source from which to import package
11122 metadata, and @var{options} specifies a package identifier and other
11123 options specific to @var{importer}.
11125 Some of the importers rely on the ability to run the @command{gpgv} command.
11126 For these, GnuPG must be installed and in @code{$PATH}; run @code{guix install
11129 Currently, the available ``importers'' are:
11133 Import metadata for the given GNU package. This provides a template
11134 for the latest version of that GNU package, including the hash of its
11135 source tarball, and its canonical synopsis and description.
11137 Additional information such as the package dependencies and its
11138 license needs to be figured out manually.
11140 For example, the following command returns a package definition for
11144 guix import gnu hello
11147 Specific command-line options are:
11150 @item --key-download=@var{policy}
11151 As for @command{guix refresh}, specify the policy to handle missing
11152 OpenPGP keys when verifying the package signature. @xref{Invoking guix
11153 refresh, @option{--key-download}}.
11158 Import metadata from the @uref{https://pypi.python.org/, Python Package
11159 Index}. Information is taken from the JSON-formatted description
11160 available at @code{pypi.python.org} and usually includes all the relevant
11161 information, including package dependencies. For maximum efficiency, it
11162 is recommended to install the @command{unzip} utility, so that the
11163 importer can unzip Python wheels and gather data from them.
11165 The command below imports metadata for the @code{itsdangerous} Python
11169 guix import pypi itsdangerous
11175 Traverse the dependency graph of the given upstream package recursively
11176 and generate package expressions for all those packages that are not yet
11182 Import metadata from @uref{https://rubygems.org/, RubyGems}. Information
11183 is taken from the JSON-formatted description available at
11184 @code{rubygems.org} and includes most relevant information, including
11185 runtime dependencies. There are some caveats, however. The metadata
11186 doesn't distinguish between synopses and descriptions, so the same string
11187 is used for both fields. Additionally, the details of non-Ruby
11188 dependencies required to build native extensions is unavailable and left
11189 as an exercise to the packager.
11191 The command below imports metadata for the @code{rails} Ruby package:
11194 guix import gem rails
11200 Traverse the dependency graph of the given upstream package recursively
11201 and generate package expressions for all those packages that are not yet
11207 Import metadata from @uref{https://www.metacpan.org/, MetaCPAN}.
11208 Information is taken from the JSON-formatted metadata provided through
11209 @uref{https://fastapi.metacpan.org/, MetaCPAN's API} and includes most
11210 relevant information, such as module dependencies. License information
11211 should be checked closely. If Perl is available in the store, then the
11212 @code{corelist} utility will be used to filter core modules out of the
11213 list of dependencies.
11215 The command command below imports metadata for the Acme::Boolean Perl
11219 guix import cpan Acme::Boolean
11224 @cindex Bioconductor
11225 Import metadata from @uref{https://cran.r-project.org/, CRAN}, the
11226 central repository for the @uref{https://r-project.org, GNU@tie{}R
11227 statistical and graphical environment}.
11229 Information is extracted from the @file{DESCRIPTION} file of the package.
11231 The command command below imports metadata for the Cairo R package:
11234 guix import cran Cairo
11237 When @option{--recursive} is added, the importer will traverse the
11238 dependency graph of the given upstream package recursively and generate
11239 package expressions for all those packages that are not yet in Guix.
11241 When @option{--style=specification} is added, the importer will generate
11242 package definitions whose inputs are package specifications instead of
11243 references to package variables. This is useful when generated package
11244 definitions are to be appended to existing user modules, as the list of
11245 used package modules need not be changed. The default is
11246 @option{--style=variable}.
11248 When @option{--archive=bioconductor} is added, metadata is imported from
11249 @uref{https://www.bioconductor.org/, Bioconductor}, a repository of R
11250 packages for the analysis and comprehension of high-throughput
11251 genomic data in bioinformatics.
11253 Information is extracted from the @file{DESCRIPTION} file contained in the
11256 The command below imports metadata for the GenomicRanges R package:
11259 guix import cran --archive=bioconductor GenomicRanges
11262 Finally, you can also import R packages that have not yet been published on
11263 CRAN or Bioconductor as long as they are in a git repository. Use
11264 @option{--archive=git} followed by the URL of the git repository:
11267 guix import cran --archive=git https://github.com/immunogenomics/harmony
11273 Import metadata from @uref{https://www.ctan.org/, CTAN}, the
11274 comprehensive TeX archive network for TeX packages that are part of the
11275 @uref{https://www.tug.org/texlive/, TeX Live distribution}.
11277 Information about the package is obtained through the XML API provided
11278 by CTAN, while the source code is downloaded from the SVN repository of
11279 the Tex Live project. This is done because the CTAN does not keep
11280 versioned archives.
11282 The command command below imports metadata for the @code{fontspec}
11286 guix import texlive fontspec
11289 When @option{--archive=@var{directory}} is added, the source code is
11290 downloaded not from the @file{latex} sub-directory of the
11291 @file{texmf-dist/source} tree in the TeX Live SVN repository, but from
11292 the specified sibling @var{directory} under the same root.
11294 The command below imports metadata for the @code{ifxetex} package from
11295 CTAN while fetching the sources from the directory
11296 @file{texmf/source/generic}:
11299 guix import texlive --archive=generic ifxetex
11303 @cindex JSON, import
11304 Import package metadata from a local JSON file. Consider the following
11305 example package definition in JSON format:
11311 "source": "mirror://gnu/hello/hello-2.10.tar.gz",
11312 "build-system": "gnu",
11313 "home-page": "https://www.gnu.org/software/hello/",
11314 "synopsis": "Hello, GNU world: An example GNU package",
11315 "description": "GNU Hello prints a greeting.",
11316 "license": "GPL-3.0+",
11317 "native-inputs": ["gettext"]
11321 The field names are the same as for the @code{<package>} record
11322 (@xref{Defining Packages}). References to other packages are provided
11323 as JSON lists of quoted package specification strings such as
11324 @code{guile} or @code{guile@@2.0}.
11326 The importer also supports a more explicit source definition using the
11327 common fields for @code{<origin>} records:
11333 "method": "url-fetch",
11334 "uri": "mirror://gnu/hello/hello-2.10.tar.gz",
11336 "base32": "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"
11343 The command below reads metadata from the JSON file @code{hello.json}
11344 and outputs a package expression:
11347 guix import json hello.json
11351 Import metadata from a local copy of the source of the
11352 @uref{https://nixos.org/nixpkgs/, Nixpkgs distribution}@footnote{This
11353 relies on the @command{nix-instantiate} command of
11354 @uref{https://nixos.org/nix/, Nix}.}. Package definitions in Nixpkgs are
11355 typically written in a mixture of Nix-language and Bash code. This
11356 command only imports the high-level package structure that is written in
11357 the Nix language. It normally includes all the basic fields of a
11358 package definition.
11360 When importing a GNU package, the synopsis and descriptions are replaced
11361 by their canonical upstream variant.
11363 Usually, you will first need to do:
11366 export NIX_REMOTE=daemon
11370 so that @command{nix-instantiate} does not try to open the Nix database.
11372 As an example, the command below imports the package definition of
11373 LibreOffice (more precisely, it imports the definition of the package
11374 bound to the @code{libreoffice} top-level attribute):
11377 guix import nix ~/path/to/nixpkgs libreoffice
11382 Import metadata from the Haskell community's central package archive
11383 @uref{https://hackage.haskell.org/, Hackage}. Information is taken from
11384 Cabal files and includes all the relevant information, including package
11387 Specific command-line options are:
11392 Read a Cabal file from standard input.
11393 @item --no-test-dependencies
11395 Do not include dependencies required only by the test suites.
11396 @item --cabal-environment=@var{alist}
11397 @itemx -e @var{alist}
11398 @var{alist} is a Scheme alist defining the environment in which the
11399 Cabal conditionals are evaluated. The accepted keys are: @code{os},
11400 @code{arch}, @code{impl} and a string representing the name of a flag.
11401 The value associated with a flag has to be either the symbol
11402 @code{true} or @code{false}. The value associated with other keys
11403 has to conform to the Cabal file format definition. The default value
11404 associated with the keys @code{os}, @code{arch} and @code{impl} is
11405 @samp{linux}, @samp{x86_64} and @samp{ghc}, respectively.
11408 Traverse the dependency graph of the given upstream package recursively
11409 and generate package expressions for all those packages that are not yet
11413 The command below imports metadata for the latest version of the
11414 HTTP Haskell package without including test dependencies and
11415 specifying the value of the flag @samp{network-uri} as @code{false}:
11418 guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
11421 A specific package version may optionally be specified by following the
11422 package name by an at-sign and a version number as in the following example:
11425 guix import hackage mtl@@2.1.3.1
11430 The @code{stackage} importer is a wrapper around the @code{hackage} one.
11431 It takes a package name, looks up the package version included in a
11432 long-term support (LTS) @uref{https://www.stackage.org, Stackage}
11433 release and uses the @code{hackage} importer to retrieve its metadata.
11434 Note that it is up to you to select an LTS release compatible with the
11435 GHC compiler used by Guix.
11437 Specific command-line options are:
11440 @item --no-test-dependencies
11442 Do not include dependencies required only by the test suites.
11443 @item --lts-version=@var{version}
11444 @itemx -l @var{version}
11445 @var{version} is the desired LTS release version. If omitted the latest
11449 Traverse the dependency graph of the given upstream package recursively
11450 and generate package expressions for all those packages that are not yet
11454 The command below imports metadata for the HTTP Haskell package
11455 included in the LTS Stackage release version 7.18:
11458 guix import stackage --lts-version=7.18 HTTP
11463 Import metadata from an Emacs Lisp Package Archive (ELPA) package
11464 repository (@pxref{Packages,,, emacs, The GNU Emacs Manual}).
11466 Specific command-line options are:
11469 @item --archive=@var{repo}
11470 @itemx -a @var{repo}
11471 @var{repo} identifies the archive repository from which to retrieve the
11472 information. Currently the supported repositories and their identifiers
11476 @uref{https://elpa.gnu.org/packages, GNU}, selected by the @code{gnu}
11477 identifier. This is the default.
11479 Packages from @code{elpa.gnu.org} are signed with one of the keys
11480 contained in the GnuPG keyring at
11481 @file{share/emacs/25.1/etc/package-keyring.gpg} (or similar) in the
11482 @code{emacs} package (@pxref{Package Installation, ELPA package
11483 signatures,, emacs, The GNU Emacs Manual}).
11486 @uref{https://stable.melpa.org/packages, MELPA-Stable}, selected by the
11487 @code{melpa-stable} identifier.
11490 @uref{https://melpa.org/packages, MELPA}, selected by the @code{melpa}
11496 Traverse the dependency graph of the given upstream package recursively
11497 and generate package expressions for all those packages that are not yet
11503 Import metadata from the crates.io Rust package repository
11504 @uref{https://crates.io, crates.io}, as in this example:
11507 guix import crate blake2-rfc
11510 The crate importer also allows you to specify a version string:
11513 guix import crate constant-time-eq@@0.1.0
11516 Additional options include:
11521 Traverse the dependency graph of the given upstream package recursively
11522 and generate package expressions for all those packages that are not yet
11529 Import metadata from the @uref{https://opam.ocaml.org/, OPAM} package
11530 repository used by the OCaml community.
11532 Additional options include:
11537 Traverse the dependency graph of the given upstream package recursively
11538 and generate package expressions for all those packages that are not yet
11541 Select the given repository (a repository name). Possible values include:
11543 @item @code{opam}, the default opam repository,
11544 @item @code{coq} or @code{coq-released}, the stable repository for coq packages,
11545 @item @code{coq-core-dev}, the repository that contains development versions of coq,
11546 @item @code{coq-extra-dev}, the repository that contains development versions
11553 Import metadata for a Go module using
11554 @uref{https://proxy.golang.org, proxy.golang.org}.
11556 This importer is highly experimental. See the source code for more info
11557 about the current state.
11560 guix import go gopkg.in/yaml.v2
11563 Additional options include:
11568 Traverse the dependency graph of the given upstream package recursively
11569 and generate package expressions for all those packages that are not yet
11574 The structure of the @command{guix import} code is modular. It would be
11575 useful to have more importers for other package formats, and your help
11576 is welcome here (@pxref{Contributing}).
11578 @node Invoking guix refresh
11579 @section Invoking @command{guix refresh}
11581 @cindex @command {guix refresh}
11582 The primary audience of the @command{guix refresh} command is packagers.
11583 As a user, you may be interested in the @option{--with-latest} option,
11584 which can bring you package update superpowers built upon @command{guix
11585 refresh} (@pxref{Package Transformation Options,
11586 @option{--with-latest}}). By default, @command{guix refresh} reports
11587 any packages provided by the distribution that are outdated compared to
11588 the latest upstream version, like this:
11592 gnu/packages/gettext.scm:29:13: gettext would be upgraded from 0.18.1.1 to 0.18.2.1
11593 gnu/packages/glib.scm:77:12: glib would be upgraded from 2.34.3 to 2.37.0
11596 Alternatively, one can specify packages to consider, in which case a
11597 warning is emitted for packages that lack an updater:
11600 $ guix refresh coreutils guile guile-ssh
11601 gnu/packages/ssh.scm:205:2: warning: no updater for guile-ssh
11602 gnu/packages/guile.scm:136:12: guile would be upgraded from 2.0.12 to 2.0.13
11605 @command{guix refresh} browses the upstream repository of each package and determines
11606 the highest version number of the releases therein. The command
11607 knows how to update specific types of packages: GNU packages, ELPA
11608 packages, etc.---see the documentation for @option{--type} below. There
11609 are many packages, though, for which it lacks a method to determine
11610 whether a new upstream release is available. However, the mechanism is
11611 extensible, so feel free to get in touch with us to add a new method!
11616 Consider the packages specified, and all the packages upon which they depend.
11619 $ guix refresh --recursive coreutils
11620 gnu/packages/acl.scm:40:13: acl would be upgraded from 2.2.53 to 2.3.1
11621 gnu/packages/m4.scm:30:12: 1.4.18 is already the latest version of m4
11622 gnu/packages/xml.scm:68:2: warning: no updater for expat
11623 gnu/packages/multiprecision.scm:40:12: 6.1.2 is already the latest version of gmp
11629 Sometimes the upstream name differs from the package name used in Guix,
11630 and @command{guix refresh} needs a little help. Most updaters honor the
11631 @code{upstream-name} property in package definitions, which can be used
11635 (define-public network-manager
11637 (name "network-manager")
11639 (properties '((upstream-name . "NetworkManager")))))
11642 When passed @option{--update}, it modifies distribution source files to
11643 update the version numbers and source tarball hashes of those package
11644 recipes (@pxref{Defining Packages}). This is achieved by downloading
11645 each package's latest source tarball and its associated OpenPGP
11646 signature, authenticating the downloaded tarball against its signature
11647 using @command{gpgv}, and finally computing its hash---note that GnuPG must be
11648 installed and in @code{$PATH}; run @code{guix install gnupg} if needed.
11651 key used to sign the tarball is missing from the user's keyring, an
11652 attempt is made to automatically retrieve it from a public key server;
11653 when this is successful, the key is added to the user's keyring; otherwise,
11654 @command{guix refresh} reports an error.
11656 The following options are supported:
11660 @item --expression=@var{expr}
11661 @itemx -e @var{expr}
11662 Consider the package @var{expr} evaluates to.
11664 This is useful to precisely refer to a package, as in this example:
11667 guix refresh -l -e '(@@@@ (gnu packages commencement) glibc-final)'
11670 This command lists the dependents of the ``final'' libc (essentially all
11675 Update distribution source files (package recipes) in place. This is
11676 usually run from a checkout of the Guix source tree (@pxref{Running
11677 Guix Before It Is Installed}):
11680 $ ./pre-inst-env guix refresh -s non-core -u
11683 @xref{Defining Packages}, for more information on package definitions.
11685 @item --select=[@var{subset}]
11686 @itemx -s @var{subset}
11687 Select all the packages in @var{subset}, one of @code{core} or
11690 The @code{core} subset refers to all the packages at the core of the
11691 distribution---i.e., packages that are used to build ``everything
11692 else''. This includes GCC, libc, Binutils, Bash, etc. Usually,
11693 changing one of these packages in the distribution entails a rebuild of
11694 all the others. Thus, such updates are an inconvenience to users in
11695 terms of build time or bandwidth used to achieve the upgrade.
11697 The @code{non-core} subset refers to the remaining packages. It is
11698 typically useful in cases where an update of the core packages would be
11701 @item --manifest=@var{file}
11702 @itemx -m @var{file}
11703 Select all the packages from the manifest in @var{file}. This is useful to
11704 check if any packages of the user manifest can be updated.
11706 @item --type=@var{updater}
11707 @itemx -t @var{updater}
11708 Select only packages handled by @var{updater} (may be a comma-separated
11709 list of updaters). Currently, @var{updater} may be one of:
11713 the updater for GNU packages;
11715 the updater for packages hosted at @uref{https://savannah.gnu.org, Savannah};
11717 the updater for packages hosted at @uref{https://sourceforge.net, SourceForge};
11719 the updater for GNOME packages;
11721 the updater for KDE packages;
11723 the updater for X.org packages;
11725 the updater for packages hosted on kernel.org;
11727 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
11729 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
11731 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
11733 the updater for @uref{https://www.cpan.org/, CPAN} packages;
11735 the updater for @uref{https://pypi.python.org, PyPI} packages.
11737 the updater for @uref{https://rubygems.org, RubyGems} packages.
11739 the updater for @uref{https://github.com, GitHub} packages.
11741 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
11743 the updater for @uref{https://www.stackage.org, Stackage} packages.
11745 the updater for @uref{https://crates.io, Crates} packages.
11747 the updater for @uref{https://launchpad.net, Launchpad} packages.
11749 a generic updater that crawls the HTML page where the source tarball of
11750 the package is hosted, when applicable.
11753 For instance, the following command only checks for updates of Emacs
11754 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
11757 $ guix refresh --type=elpa,cran
11758 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
11759 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
11762 @item --list-updaters
11764 List available updaters and exit (see @option{--type} above).
11766 For each updater, display the fraction of packages it covers; at the
11767 end, display the fraction of packages covered by all these updaters.
11770 In addition, @command{guix refresh} can be passed one or more package
11771 names, as in this example:
11774 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
11778 The command above specifically updates the @code{emacs} and
11779 @code{idutils} packages. The @option{--select} option would have no
11780 effect in this case. You might also want to update definitions that
11781 correspond to the packages installed in your profile:
11784 $ ./pre-inst-env guix refresh -u \
11785 $(guix package --list-installed | cut -f1)
11788 When considering whether to upgrade a package, it is sometimes
11789 convenient to know which packages would be affected by the upgrade and
11790 should be checked for compatibility. For this the following option may
11791 be used when passing @command{guix refresh} one or more package names:
11795 @item --list-dependent
11797 List top-level dependent packages that would need to be rebuilt as a
11798 result of upgrading one or more packages.
11800 @xref{Invoking guix graph, the @code{reverse-package} type of
11801 @command{guix graph}}, for information on how to visualize the list of
11802 dependents of a package.
11806 Be aware that the @option{--list-dependent} option only
11807 @emph{approximates} the rebuilds that would be required as a result of
11808 an upgrade. More rebuilds might be required under some circumstances.
11811 $ guix refresh --list-dependent flex
11812 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
11813 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
11816 The command above lists a set of packages that could be built to check
11817 for compatibility with an upgraded @code{flex} package.
11821 @item --list-transitive
11822 List all the packages which one or more packages depend upon.
11825 $ guix refresh --list-transitive flex
11826 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
11827 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{}
11832 The command above lists a set of packages which, when changed, would cause
11833 @code{flex} to be rebuilt.
11835 The following options can be used to customize GnuPG operation:
11839 @item --gpg=@var{command}
11840 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
11841 for in @code{$PATH}.
11843 @item --keyring=@var{file}
11844 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
11845 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
11846 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
11847 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
11848 information on a tool to manipulate keybox files).
11850 When this option is omitted, @command{guix refresh} uses
11851 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
11852 signing keys. OpenPGP signatures are checked against keys from this keyring;
11853 missing keys are downloaded to this keyring as well (see
11854 @option{--key-download} below).
11856 You can export keys from your default GPG keyring into a keybox file using
11857 commands like this one:
11860 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
11863 Likewise, you can fetch keys to a specific keybox file like this:
11866 gpg --no-default-keyring --keyring mykeyring.kbx \
11867 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
11870 @xref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
11871 Privacy Guard}, for more information on GPG's @option{--keyring} option.
11873 @item --key-download=@var{policy}
11874 Handle missing OpenPGP keys according to @var{policy}, which may be one
11879 Always download missing OpenPGP keys from the key server, and add them
11880 to the user's GnuPG keyring.
11883 Never try to download missing OpenPGP keys. Instead just bail out.
11886 When a package signed with an unknown OpenPGP key is encountered, ask
11887 the user whether to download it or not. This is the default behavior.
11890 @item --key-server=@var{host}
11891 Use @var{host} as the OpenPGP key server when importing a public key.
11893 @item --load-path=@var{directory}
11894 Add @var{directory} to the front of the package module search path
11895 (@pxref{Package Modules}).
11897 This allows users to define their own packages and make them visible to
11898 the command-line tools.
11902 The @code{github} updater uses the
11903 @uref{https://developer.github.com/v3/, GitHub API} to query for new
11904 releases. When used repeatedly e.g.@: when refreshing all packages,
11905 GitHub will eventually refuse to answer any further API requests. By
11906 default 60 API requests per hour are allowed, and a full refresh on all
11907 GitHub packages in Guix requires more than this. Authentication with
11908 GitHub through the use of an API token alleviates these limits. To use
11909 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
11910 token procured from @uref{https://github.com/settings/tokens} or
11914 @node Invoking guix lint
11915 @section Invoking @command{guix lint}
11917 @cindex @command{guix lint}
11918 @cindex package, checking for errors
11919 The @command{guix lint} command is meant to help package developers avoid
11920 common errors and use a consistent style. It runs a number of checks on
11921 a given set of packages in order to find common mistakes in their
11922 definitions. Available @dfn{checkers} include (see
11923 @option{--list-checkers} for a complete list):
11928 Validate certain typographical and stylistic rules about package
11929 descriptions and synopses.
11931 @item inputs-should-be-native
11932 Identify inputs that should most likely be native inputs.
11938 @itemx source-file-name
11939 Probe @code{home-page} and @code{source} URLs and report those that are
11940 invalid. Suggest a @code{mirror://} URL when applicable. If the
11941 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
11942 URL@. Check that the source file name is meaningful, e.g.@: is not just a
11943 version number or ``git-checkout'', without a declared @code{file-name}
11944 (@pxref{origin Reference}).
11946 @item source-unstable-tarball
11947 Parse the @code{source} URL to determine if a tarball from GitHub is
11948 autogenerated or if it is a release tarball. Unfortunately GitHub's
11949 autogenerated tarballs are sometimes regenerated.
11952 Check that the derivation of the given packages can be successfully
11953 computed for all the supported systems (@pxref{Derivations}).
11955 @item profile-collisions
11956 Check whether installing the given packages in a profile would lead to
11957 collisions. Collisions occur when several packages with the same name
11958 but a different version or a different store file name are propagated.
11959 @xref{package Reference, @code{propagated-inputs}}, for more information
11960 on propagated inputs.
11963 @cindex Software Heritage, source code archive
11964 @cindex archival of source code, Software Heritage
11965 Checks whether the package's source code is archived at
11966 @uref{https://www.softwareheritage.org, Software Heritage}.
11968 When the source code that is not archived comes from a version-control system
11969 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
11970 ``save'' request so that it eventually archives it. This ensures that the
11971 source will remain available in the long term, and that Guix can fall back to
11972 Software Heritage should the source code disappear from its original host.
11973 The status of recent ``save'' requests can be
11974 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
11976 When source code is a tarball obtained with @code{url-fetch}, simply print a
11977 message when it is not archived. As of this writing, Software Heritage does
11978 not allow requests to save arbitrary tarballs; we are working on ways to
11979 ensure that non-VCS source code is also archived.
11982 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
11983 request rate per IP address}. When the limit is reached, @command{guix lint}
11984 prints a message and the @code{archival} checker stops doing anything until
11985 that limit has been reset.
11988 @cindex security vulnerabilities
11989 @cindex CVE, Common Vulnerabilities and Exposures
11990 Report known vulnerabilities found in the Common Vulnerabilities and
11991 Exposures (CVE) databases of the current and past year
11992 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
11995 To view information about a particular vulnerability, visit pages such as:
11999 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
12001 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
12005 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
12006 @code{CVE-2015-7554}.
12008 Package developers can specify in package recipes the
12009 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
12010 name and version of the package when they differ from the name or version
12011 that Guix uses, as in this example:
12017 ;; CPE calls this package "grub2".
12018 (properties '((cpe-name . "grub2")
12019 (cpe-version . "2.3"))))
12022 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
12023 Some entries in the CVE database do not specify which version of a
12024 package they apply to, and would thus ``stick around'' forever. Package
12025 developers who found CVE alerts and verified they can be ignored can
12026 declare them as in this example:
12032 ;; These CVEs no longer apply and can be safely ignored.
12033 (properties `((lint-hidden-cve . ("CVE-2011-0433"
12036 "CVE-2011-5244")))))
12040 Warn about obvious source code formatting issues: trailing white space,
12041 use of tabulations, etc.
12044 The general syntax is:
12047 guix lint @var{options} @var{package}@dots{}
12050 If no package is given on the command line, then all packages are checked.
12051 The @var{options} may be zero or more of the following:
12054 @item --list-checkers
12056 List and describe all the available checkers that will be run on packages
12061 Only enable the checkers specified in a comma-separated list using the
12062 names returned by @option{--list-checkers}.
12066 Only disable the checkers specified in a comma-separated list using the
12067 names returned by @option{--list-checkers}.
12071 Only enable the checkers that do not depend on Internet access.
12073 @item --load-path=@var{directory}
12074 @itemx -L @var{directory}
12075 Add @var{directory} to the front of the package module search path
12076 (@pxref{Package Modules}).
12078 This allows users to define their own packages and make them visible to
12079 the command-line tools.
12083 @node Invoking guix size
12084 @section Invoking @command{guix size}
12087 @cindex package size
12089 @cindex @command{guix size}
12090 The @command{guix size} command helps package developers profile the
12091 disk usage of packages. It is easy to overlook the impact of an
12092 additional dependency added to a package, or the impact of using a
12093 single output for a package that could easily be split (@pxref{Packages
12094 with Multiple Outputs}). Such are the typical issues that
12095 @command{guix size} can highlight.
12097 The command can be passed one or more package specifications
12098 such as @code{gcc@@4.8}
12099 or @code{guile:debug}, or a file name in the store. Consider this
12103 $ guix size coreutils
12104 store item total self
12105 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
12106 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
12107 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
12108 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
12109 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
12110 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
12111 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
12112 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
12117 The store items listed here constitute the @dfn{transitive closure} of
12118 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
12119 would be returned by:
12122 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
12125 Here the output shows three columns next to store items. The first column,
12126 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
12127 the store item---that is, its own size plus the size of all its
12128 dependencies. The next column, labeled ``self'', shows the size of the
12129 item itself. The last column shows the ratio of the size of the item
12130 itself to the space occupied by all the items listed here.
12132 In this example, we see that the closure of Coreutils weighs in at
12133 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
12134 libraries. (That libc and GCC's libraries represent a large fraction of
12135 the closure is not a problem @i{per se} because they are always available
12136 on the system anyway.)
12138 Since the command also accepts store file names, assessing the size of
12139 a build result is straightforward:
12142 guix size $(guix system build config.scm)
12145 When the package(s) passed to @command{guix size} are available in the
12146 store@footnote{More precisely, @command{guix size} looks for the
12147 @emph{ungrafted} variant of the given package(s), as returned by
12148 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
12149 for information on grafts.}, @command{guix size} queries the daemon to determine its
12150 dependencies, and measures its size in the store, similar to @command{du
12151 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
12154 When the given packages are @emph{not} in the store, @command{guix size}
12155 reports information based on the available substitutes
12156 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
12157 store items that are not even on disk, only available remotely.
12159 You can also specify several package names:
12162 $ guix size coreutils grep sed bash
12163 store item total self
12164 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
12165 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
12166 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
12167 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
12173 In this example we see that the combination of the four packages takes
12174 102.3@tie{}MiB in total, which is much less than the sum of each closure
12175 since they have a lot of dependencies in common.
12177 When looking at the profile returned by @command{guix size}, you may
12178 find yourself wondering why a given package shows up in the profile at
12179 all. To understand it, you can use @command{guix graph --path -t
12180 references} to display the shortest path between the two packages
12181 (@pxref{Invoking guix graph}).
12183 The available options are:
12187 @item --substitute-urls=@var{urls}
12188 Use substitute information from @var{urls}.
12189 @xref{client-substitute-urls, the same option for @code{guix build}}.
12191 @item --sort=@var{key}
12192 Sort lines according to @var{key}, one of the following options:
12196 the size of each item (the default);
12198 the total size of the item's closure.
12201 @item --map-file=@var{file}
12202 Write a graphical map of disk usage in PNG format to @var{file}.
12204 For the example above, the map looks like this:
12206 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
12207 produced by @command{guix size}}
12209 This option requires that
12210 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
12211 installed and visible in Guile's module search path. When that is not
12212 the case, @command{guix size} fails as it tries to load it.
12214 @item --system=@var{system}
12215 @itemx -s @var{system}
12216 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
12218 @item --load-path=@var{directory}
12219 @itemx -L @var{directory}
12220 Add @var{directory} to the front of the package module search path
12221 (@pxref{Package Modules}).
12223 This allows users to define their own packages and make them visible to
12224 the command-line tools.
12227 @node Invoking guix graph
12228 @section Invoking @command{guix graph}
12231 @cindex @command{guix graph}
12232 @cindex package dependencies
12233 Packages and their dependencies form a @dfn{graph}, specifically a
12234 directed acyclic graph (DAG). It can quickly become difficult to have a
12235 mental model of the package DAG, so the @command{guix graph} command
12236 provides a visual representation of the DAG@. By default,
12237 @command{guix graph} emits a DAG representation in the input format of
12238 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
12239 directly to the @command{dot} command of Graphviz. It can also emit an
12240 HTML page with embedded JavaScript code to display a ``chord diagram''
12241 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
12242 emit Cypher queries to construct a graph in a graph database supporting
12243 the @uref{https://www.opencypher.org/, openCypher} query language. With
12244 @option{--path}, it simply displays the shortest path between two
12245 packages. The general syntax is:
12248 guix graph @var{options} @var{package}@dots{}
12251 For example, the following command generates a PDF file representing the
12252 package DAG for the GNU@tie{}Core Utilities, showing its build-time
12256 guix graph coreutils | dot -Tpdf > dag.pdf
12259 The output looks like this:
12261 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
12263 Nice little graph, no?
12265 You may find it more pleasant to navigate the graph interactively with
12266 @command{xdot} (from the @code{xdot} package):
12269 guix graph coreutils | xdot -
12272 But there is more than one graph! The one above is concise: it is the
12273 graph of package objects, omitting implicit inputs such as GCC, libc,
12274 grep, etc. It is often useful to have such a concise graph, but
12275 sometimes one may want to see more details. @command{guix graph} supports
12276 several types of graphs, allowing you to choose the level of detail:
12280 This is the default type used in the example above. It shows the DAG of
12281 package objects, excluding implicit dependencies. It is concise, but
12282 filters out many details.
12284 @item reverse-package
12285 This shows the @emph{reverse} DAG of packages. For example:
12288 guix graph --type=reverse-package ocaml
12291 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
12292 you are also interested in cases where OCaml is an implicit dependency, see
12293 @code{reverse-bag} below).
12295 Note that for core packages this can yield huge graphs. If all you want
12296 is to know the number of packages that depend on a given package, use
12297 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
12298 @option{--list-dependent}}).
12301 This is the package DAG, @emph{including} implicit inputs.
12303 For instance, the following command:
12306 guix graph --type=bag-emerged coreutils
12309 ...@: yields this bigger graph:
12311 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
12313 At the bottom of the graph, we see all the implicit inputs of
12314 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
12316 Now, note that the dependencies of these implicit inputs---that is, the
12317 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
12318 here, for conciseness.
12321 Similar to @code{bag-emerged}, but this time including all the bootstrap
12324 @item bag-with-origins
12325 Similar to @code{bag}, but also showing origins and their dependencies.
12328 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
12329 it also takes implicit dependencies into account. For example:
12332 guix graph -t reverse-bag dune
12336 ...@: yields the graph of all packages that depend on Dune, directly or
12337 indirectly. Since Dune is an @emph{implicit} dependency of many packages
12338 @i{via} @code{dune-build-system}, this shows a large number of packages,
12339 whereas @code{reverse-package} would show very few if any.
12342 This is the most detailed representation: It shows the DAG of
12343 derivations (@pxref{Derivations}) and plain store items. Compared to
12344 the above representation, many additional nodes are visible, including
12345 build scripts, patches, Guile modules, etc.
12347 For this type of graph, it is also possible to pass a @file{.drv} file
12348 name instead of a package name, as in:
12351 guix graph -t derivation $(guix system build -d my-config.scm)
12355 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
12356 For example, the following command shows the graph for the package
12357 module that defines the @code{guile} package:
12360 guix graph -t module guile | xdot -
12364 All the types above correspond to @emph{build-time dependencies}. The
12365 following graph type represents the @emph{run-time dependencies}:
12369 This is the graph of @dfn{references} of a package output, as returned
12370 by @command{guix gc --references} (@pxref{Invoking guix gc}).
12372 If the given package output is not available in the store, @command{guix
12373 graph} attempts to obtain dependency information from substitutes.
12375 Here you can also pass a store file name instead of a package name. For
12376 example, the command below produces the reference graph of your profile
12377 (which can be big!):
12380 guix graph -t references $(readlink -f ~/.guix-profile)
12384 This is the graph of the @dfn{referrers} of a store item, as returned by
12385 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
12387 This relies exclusively on local information from your store. For
12388 instance, let us suppose that the current Inkscape is available in 10
12389 profiles on your machine; @command{guix graph -t referrers inkscape}
12390 will show a graph rooted at Inkscape and with those 10 profiles linked
12393 It can help determine what is preventing a store item from being garbage
12398 @cindex shortest path, between packages
12399 Often, the graph of the package you are interested in does not fit on
12400 your screen, and anyway all you want to know is @emph{why} that package
12401 actually depends on some seemingly unrelated package. The
12402 @option{--path} option instructs @command{guix graph} to display the
12403 shortest path between two packages (or derivations, or store items,
12407 $ guix graph --path emacs libunistring
12410 libunistring@@0.9.10
12411 $ guix graph --path -t derivation emacs libunistring
12412 /gnu/store/@dots{}-emacs-26.3.drv
12413 /gnu/store/@dots{}-mailutils-3.9.drv
12414 /gnu/store/@dots{}-libunistring-0.9.10.drv
12415 $ guix graph --path -t references emacs libunistring
12416 /gnu/store/@dots{}-emacs-26.3
12417 /gnu/store/@dots{}-libidn2-2.2.0
12418 /gnu/store/@dots{}-libunistring-0.9.10
12421 The available options are the following:
12424 @item --type=@var{type}
12425 @itemx -t @var{type}
12426 Produce a graph output of @var{type}, where @var{type} must be one of
12427 the values listed above.
12430 List the supported graph types.
12432 @item --backend=@var{backend}
12433 @itemx -b @var{backend}
12434 Produce a graph using the selected @var{backend}.
12436 @item --list-backends
12437 List the supported graph backends.
12439 Currently, the available backends are Graphviz and d3.js.
12442 Display the shortest path between two nodes of the type specified by
12443 @option{--type}. The example below shows the shortest path between
12444 @code{libreoffice} and @code{llvm} according to the references of
12445 @code{libreoffice}:
12448 $ guix graph --path -t references libreoffice llvm
12449 /gnu/store/@dots{}-libreoffice-6.4.2.2
12450 /gnu/store/@dots{}-libepoxy-1.5.4
12451 /gnu/store/@dots{}-mesa-19.3.4
12452 /gnu/store/@dots{}-llvm-9.0.1
12455 @item --expression=@var{expr}
12456 @itemx -e @var{expr}
12457 Consider the package @var{expr} evaluates to.
12459 This is useful to precisely refer to a package, as in this example:
12462 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
12465 @item --system=@var{system}
12466 @itemx -s @var{system}
12467 Display the graph for @var{system}---e.g., @code{i686-linux}.
12469 The package dependency graph is largely architecture-independent, but there
12470 are some architecture-dependent bits that this option allows you to visualize.
12472 @item --load-path=@var{directory}
12473 @itemx -L @var{directory}
12474 Add @var{directory} to the front of the package module search path
12475 (@pxref{Package Modules}).
12477 This allows users to define their own packages and make them visible to
12478 the command-line tools.
12481 On top of that, @command{guix graph} supports all the usual package
12482 transformation options (@pxref{Package Transformation Options}). This
12483 makes it easy to view the effect of a graph-rewriting transformation
12484 such as @option{--with-input}. For example, the command below outputs
12485 the graph of @code{git} once @code{openssl} has been replaced by
12486 @code{libressl} everywhere in the graph:
12489 guix graph git --with-input=openssl=libressl
12492 So many possibilities, so much fun!
12494 @node Invoking guix publish
12495 @section Invoking @command{guix publish}
12497 @cindex @command{guix publish}
12498 The purpose of @command{guix publish} is to enable users to easily share
12499 their store with others, who can then use it as a substitute server
12500 (@pxref{Substitutes}).
12502 When @command{guix publish} runs, it spawns an HTTP server which allows
12503 anyone with network access to obtain substitutes from it. This means
12504 that any machine running Guix can also act as if it were a build farm,
12505 since the HTTP interface is compatible with Cuirass, the software behind
12506 the @code{@value{SUBSTITUTE-SERVER}} build farm.
12508 For security, each substitute is signed, allowing recipients to check
12509 their authenticity and integrity (@pxref{Substitutes}). Because
12510 @command{guix publish} uses the signing key of the system, which is only
12511 readable by the system administrator, it must be started as root; the
12512 @option{--user} option makes it drop root privileges early on.
12514 The signing key pair must be generated before @command{guix publish} is
12515 launched, using @command{guix archive --generate-key} (@pxref{Invoking
12518 When the @option{--advertise} option is passed, the server advertises
12519 its availability on the local network using multicast DNS (mDNS) and DNS
12520 service discovery (DNS-SD), currently @i{via} Guile-Avahi (@pxref{Top,,,
12521 guile-avahi, Using Avahi in Guile Scheme Programs}).
12523 The general syntax is:
12526 guix publish @var{options}@dots{}
12529 Running @command{guix publish} without any additional arguments will
12530 spawn an HTTP server on port 8080:
12536 Once a publishing server has been authorized, the daemon may download
12537 substitutes from it. @xref{Getting Substitutes from Other Servers}.
12539 By default, @command{guix publish} compresses archives on the fly as it
12540 serves them. This ``on-the-fly'' mode is convenient in that it requires
12541 no setup and is immediately available. However, when serving lots of
12542 clients, we recommend using the @option{--cache} option, which enables
12543 caching of the archives before they are sent to clients---see below for
12544 details. The @command{guix weather} command provides a handy way to
12545 check what a server provides (@pxref{Invoking guix weather}).
12547 As a bonus, @command{guix publish} also serves as a content-addressed
12548 mirror for source files referenced in @code{origin} records
12549 (@pxref{origin Reference}). For instance, assuming @command{guix
12550 publish} is running on @code{example.org}, the following URL returns the
12551 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
12552 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
12555 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
12558 Obviously, these URLs only work for files that are in the store; in
12559 other cases, they return 404 (``Not Found'').
12561 @cindex build logs, publication
12562 Build logs are available from @code{/log} URLs like:
12565 http://example.org/log/gwspk@dots{}-guile-2.2.3
12569 When @command{guix-daemon} is configured to save compressed build logs,
12570 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
12571 URLs return the compressed log as-is, with an appropriate
12572 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
12573 running @command{guix-daemon} with @option{--log-compression=gzip} since
12574 Web browsers can automatically decompress it, which is not the case with
12577 The following options are available:
12580 @item --port=@var{port}
12581 @itemx -p @var{port}
12582 Listen for HTTP requests on @var{port}.
12584 @item --listen=@var{host}
12585 Listen on the network interface for @var{host}. The default is to
12586 accept connections from any interface.
12588 @item --user=@var{user}
12589 @itemx -u @var{user}
12590 Change privileges to @var{user} as soon as possible---i.e., once the
12591 server socket is open and the signing key has been read.
12593 @item --compression[=@var{method}[:@var{level}]]
12594 @itemx -C [@var{method}[:@var{level}]]
12595 Compress data using the given @var{method} and @var{level}. @var{method} is
12596 one of @code{lzip}, @code{zstd}, and @code{gzip}; when @var{method} is
12597 omitted, @code{gzip} is used.
12599 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
12600 to different compression levels: 1 is the fastest, and 9 is the best
12601 (CPU-intensive). The default is 3.
12603 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a
12604 small increase in CPU usage; see
12605 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip
12606 Web page}. However, @code{lzip} achieves low decompression throughput
12607 (on the order of 50@tie{}MiB/s on modern hardware), which can be a
12608 bottleneck for someone who downloads over a fast network connection.
12610 The compression ratio of @code{zstd} is between that of @code{lzip} and
12611 that of @code{gzip}; its main advantage is a
12612 @uref{https://facebook.github.io/zstd/,high decompression speed}.
12614 Unless @option{--cache} is used, compression occurs on the fly and
12615 the compressed streams are not
12616 cached. Thus, to reduce load on the machine that runs @command{guix
12617 publish}, it may be a good idea to choose a low compression level, to
12618 run @command{guix publish} behind a caching proxy, or to use
12619 @option{--cache}. Using @option{--cache} has the advantage that it
12620 allows @command{guix publish} to add @code{Content-Length} HTTP header
12623 This option can be repeated, in which case every substitute gets compressed
12624 using all the selected methods, and all of them are advertised. This is
12625 useful when users may not support all the compression methods: they can select
12626 the one they support.
12628 @item --cache=@var{directory}
12629 @itemx -c @var{directory}
12630 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
12631 and only serve archives that are in cache.
12633 When this option is omitted, archives and meta-data are created
12634 on-the-fly. This can reduce the available bandwidth, especially when
12635 compression is enabled, since this may become CPU-bound. Another
12636 drawback of the default mode is that the length of archives is not known
12637 in advance, so @command{guix publish} does not add a
12638 @code{Content-Length} HTTP header to its responses, which in turn
12639 prevents clients from knowing the amount of data being downloaded.
12641 Conversely, when @option{--cache} is used, the first request for a store
12642 item (@i{via} a @code{.narinfo} URL) triggers a
12643 background process to @dfn{bake} the archive---computing its
12644 @code{.narinfo} and compressing the archive, if needed. Once the
12645 archive is cached in @var{directory}, subsequent requests succeed and
12646 are served directly from the cache, which guarantees that clients get
12647 the best possible bandwidth.
12649 That first @code{.narinfo} request nonetheless returns 200, provided the
12650 requested store item is ``small enough'', below the cache bypass
12651 threshold---see @option{--cache-bypass-threshold} below. That way,
12652 clients do not have to wait until the archive is baked. For larger
12653 store items, the first @code{.narinfo} request returns 404, meaning that
12654 clients have to wait until the archive is baked.
12656 The ``baking'' process is performed by worker threads. By default, one
12657 thread per CPU core is created, but this can be customized. See
12658 @option{--workers} below.
12660 When @option{--ttl} is used, cached entries are automatically deleted
12661 when they have expired.
12663 @item --workers=@var{N}
12664 When @option{--cache} is used, request the allocation of @var{N} worker
12665 threads to ``bake'' archives.
12667 @item --ttl=@var{ttl}
12668 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
12669 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
12670 days, @code{1m} means 1 month, and so on.
12672 This allows the user's Guix to keep substitute information in cache for
12673 @var{ttl}. However, note that @code{guix publish} does not itself
12674 guarantee that the store items it provides will indeed remain available
12675 for as long as @var{ttl}.
12677 Additionally, when @option{--cache} is used, cached entries that have
12678 not been accessed for @var{ttl} and that no longer have a corresponding
12679 item in the store, may be deleted.
12681 @item --cache-bypass-threshold=@var{size}
12682 When used in conjunction with @option{--cache}, store items smaller than
12683 @var{size} are immediately available, even when they are not yet in
12684 cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
12685 for megabytes and so on. The default is @code{10M}.
12687 ``Cache bypass'' allows you to reduce the publication delay for clients
12688 at the expense of possibly additional I/O and CPU use on the server
12689 side: depending on the client access patterns, those store items can end
12690 up being baked several times until a copy is available in cache.
12692 Increasing the threshold may be useful for sites that have few users, or
12693 to guarantee that users get substitutes even for store items that are
12696 @item --nar-path=@var{path}
12697 Use @var{path} as the prefix for the URLs of ``nar'' files
12698 (@pxref{Invoking guix archive, normalized archives}).
12700 By default, nars are served at a URL such as
12701 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
12702 change the @code{/nar} part to @var{path}.
12704 @item --public-key=@var{file}
12705 @itemx --private-key=@var{file}
12706 Use the specific @var{file}s as the public/private key pair used to sign
12707 the store items being published.
12709 The files must correspond to the same key pair (the private key is used
12710 for signing and the public key is merely advertised in the signature
12711 metadata). They must contain keys in the canonical s-expression format
12712 as produced by @command{guix archive --generate-key} (@pxref{Invoking
12713 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
12714 @file{/etc/guix/signing-key.sec} are used.
12716 @item --repl[=@var{port}]
12717 @itemx -r [@var{port}]
12718 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
12719 Reference Manual}) on @var{port} (37146 by default). This is used
12720 primarily for debugging a running @command{guix publish} server.
12723 Enabling @command{guix publish} on Guix System is a one-liner: just
12724 instantiate a @code{guix-publish-service-type} service in the @code{services} field
12725 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
12726 @code{guix-publish-service-type}}).
12728 If you are instead running Guix on a ``foreign distro'', follow these
12733 If your host distro uses the systemd init system:
12736 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
12737 /etc/systemd/system/
12738 # systemctl start guix-publish && systemctl enable guix-publish
12742 If your host distro uses the Upstart init system:
12745 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
12746 # start guix-publish
12750 Otherwise, proceed similarly with your distro's init system.
12753 @node Invoking guix challenge
12754 @section Invoking @command{guix challenge}
12756 @cindex reproducible builds
12757 @cindex verifiable builds
12758 @cindex @command{guix challenge}
12760 Do the binaries provided by this server really correspond to the source
12761 code it claims to build? Is a package build process deterministic?
12762 These are the questions the @command{guix challenge} command attempts to
12765 The former is obviously an important question: Before using a substitute
12766 server (@pxref{Substitutes}), one had better @emph{verify} that it
12767 provides the right binaries, and thus @emph{challenge} it. The latter
12768 is what enables the former: If package builds are deterministic, then
12769 independent builds of the package should yield the exact same result,
12770 bit for bit; if a server provides a binary different from the one
12771 obtained locally, it may be either corrupt or malicious.
12773 We know that the hash that shows up in @file{/gnu/store} file names is
12774 the hash of all the inputs of the process that built the file or
12775 directory---compilers, libraries, build scripts,
12776 etc. (@pxref{Introduction}). Assuming deterministic build processes,
12777 one store file name should map to exactly one build output.
12778 @command{guix challenge} checks whether there is, indeed, a single
12779 mapping by comparing the build outputs of several independent builds of
12780 any given store item.
12782 The command output looks like this:
12785 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12786 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
12787 updating list of substitutes from 'https://guix.example.org'... 100.0%
12788 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
12789 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12790 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12791 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
12793 /lib/libcrypto.so.1.1
12796 /gnu/store/@dots{}-git-2.5.0 contents differ:
12797 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
12798 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
12799 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
12801 /libexec/git-core/git-fsck
12803 /gnu/store/@dots{}-pius-2.1.1 contents differ:
12804 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12805 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12806 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
12808 /share/man/man1/pius.1.gz
12812 6,406 store items were analyzed:
12813 - 4,749 (74.1%) were identical
12814 - 525 (8.2%) differed
12815 - 1,132 (17.7%) were inconclusive
12819 In this example, @command{guix challenge} first scans the store to
12820 determine the set of locally-built derivations---as opposed to store
12821 items that were downloaded from a substitute server---and then queries
12822 all the substitute servers. It then reports those store items for which
12823 the servers obtained a result different from the local build.
12825 @cindex non-determinism, in package builds
12826 As an example, @code{guix.example.org} always gets a different answer.
12827 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
12828 case of Git. This might indicate that the build process of Git is
12829 non-deterministic, meaning that its output varies as a function of
12830 various things that Guix does not fully control, in spite of building
12831 packages in isolated environments (@pxref{Features}). Most common
12832 sources of non-determinism include the addition of timestamps in build
12833 results, the inclusion of random numbers, and directory listings sorted
12834 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
12837 To find out what is wrong with this Git binary, the easiest approach is
12841 guix challenge git \
12842 --diff=diffoscope \
12843 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12846 This automatically invokes @command{diffoscope}, which displays detailed
12847 information about files that differ.
12849 Alternatively, we can do something along these lines (@pxref{Invoking guix
12853 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
12854 | lzip -d | guix archive -x /tmp/git
12855 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
12858 This command shows the difference between the files resulting from the
12859 local build, and the files resulting from the build on
12860 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
12861 diffutils, Comparing and Merging Files}). The @command{diff} command
12862 works great for text files. When binary files differ, a better option
12863 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
12864 visualize differences for all kinds of files.
12866 Once you have done that work, you can tell whether the differences are due
12867 to a non-deterministic build process or to a malicious server. We try
12868 hard to remove sources of non-determinism in packages to make it easier
12869 to verify substitutes, but of course, this is a process that
12870 involves not just Guix, but a large part of the free software community.
12871 In the meantime, @command{guix challenge} is one tool to help address
12874 If you are writing packages for Guix, you are encouraged to check
12875 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
12876 same build result as you did with:
12879 $ guix challenge @var{package}
12883 where @var{package} is a package specification such as
12884 @code{guile@@2.0} or @code{glibc:debug}.
12886 The general syntax is:
12889 guix challenge @var{options} [@var{packages}@dots{}]
12892 When a difference is found between the hash of a locally-built item and
12893 that of a server-provided substitute, or among substitutes provided by
12894 different servers, the command displays it as in the example above and
12895 its exit code is 2 (other non-zero exit codes denote other kinds of
12898 The one option that matters is:
12902 @item --substitute-urls=@var{urls}
12903 Consider @var{urls} the whitespace-separated list of substitute source
12904 URLs to compare to.
12906 @item --diff=@var{mode}
12907 Upon mismatches, show differences according to @var{mode}, one of:
12910 @item @code{simple} (the default)
12911 Show the list of files that differ.
12913 @item @code{diffoscope}
12914 @itemx @var{command}
12915 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
12916 two directories whose contents do not match.
12918 When @var{command} is an absolute file name, run @var{command} instead
12922 Do not show further details about the differences.
12925 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
12926 downloads the store items from the given substitute servers so that it
12931 Show details about matches (identical contents) in addition to
12932 information about mismatches.
12936 @node Invoking guix copy
12937 @section Invoking @command{guix copy}
12939 @cindex copy, of store items, over SSH
12940 @cindex SSH, copy of store items
12941 @cindex sharing store items across machines
12942 @cindex transferring store items across machines
12943 The @command{guix copy} command copies items from the store of one
12944 machine to that of another machine over a secure shell (SSH)
12945 connection@footnote{This command is available only when Guile-SSH was
12946 found. @xref{Requirements}, for details.}. For example, the following
12947 command copies the @code{coreutils} package, the user's profile, and all
12948 their dependencies over to @var{host}, logged in as @var{user}:
12951 guix copy --to=@var{user}@@@var{host} \
12952 coreutils $(readlink -f ~/.guix-profile)
12955 If some of the items to be copied are already present on @var{host},
12956 they are not actually sent.
12958 The command below retrieves @code{libreoffice} and @code{gimp} from
12959 @var{host}, assuming they are available there:
12962 guix copy --from=@var{host} libreoffice gimp
12965 The SSH connection is established using the Guile-SSH client, which is
12966 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
12967 @file{~/.ssh/config}, and uses the SSH agent for authentication.
12969 The key used to sign items that are sent must be accepted by the remote
12970 machine. Likewise, the key used by the remote machine to sign items you
12971 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
12972 own daemon. @xref{Invoking guix archive}, for more information about
12973 store item authentication.
12975 The general syntax is:
12978 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
12981 You must always specify one of the following options:
12984 @item --to=@var{spec}
12985 @itemx --from=@var{spec}
12986 Specify the host to send to or receive from. @var{spec} must be an SSH
12987 spec such as @code{example.org}, @code{charlie@@example.org}, or
12988 @code{charlie@@example.org:2222}.
12991 The @var{items} can be either package names, such as @code{gimp}, or
12992 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
12994 When specifying the name of a package to send, it is first built if
12995 needed, unless @option{--dry-run} was specified. Common build options
12996 are supported (@pxref{Common Build Options}).
12999 @node Invoking guix container
13000 @section Invoking @command{guix container}
13002 @cindex @command{guix container}
13004 As of version @value{VERSION}, this tool is experimental. The interface
13005 is subject to radical change in the future.
13008 The purpose of @command{guix container} is to manipulate processes
13009 running within an isolated environment, commonly known as a
13010 ``container'', typically created by the @command{guix environment}
13011 (@pxref{Invoking guix environment}) and @command{guix system container}
13012 (@pxref{Invoking guix system}) commands.
13014 The general syntax is:
13017 guix container @var{action} @var{options}@dots{}
13020 @var{action} specifies the operation to perform with a container, and
13021 @var{options} specifies the context-specific arguments for the action.
13023 The following actions are available:
13027 Execute a command within the context of a running container.
13032 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
13035 @var{pid} specifies the process ID of the running container.
13036 @var{program} specifies an executable file name within the root file
13037 system of the container. @var{arguments} are the additional options that
13038 will be passed to @var{program}.
13040 The following command launches an interactive login shell inside a
13041 Guix system container, started by @command{guix system container}, and whose
13042 process ID is 9001:
13045 guix container exec 9001 /run/current-system/profile/bin/bash --login
13048 Note that the @var{pid} cannot be the parent process of a container. It
13049 must be PID 1 of the container or one of its child processes.
13053 @node Invoking guix weather
13054 @section Invoking @command{guix weather}
13056 Occasionally you're grumpy because substitutes are lacking and you end
13057 up building packages by yourself (@pxref{Substitutes}). The
13058 @command{guix weather} command reports on substitute availability on the
13059 specified servers so you can have an idea of whether you'll be grumpy
13060 today. It can sometimes be useful info as a user, but it is primarily
13061 useful to people running @command{guix publish} (@pxref{Invoking guix
13064 @cindex statistics, for substitutes
13065 @cindex availability of substitutes
13066 @cindex substitute availability
13067 @cindex weather, substitute availability
13068 Here's a sample run:
13071 $ guix weather --substitute-urls=https://guix.example.org
13072 computing 5,872 package derivations for x86_64-linux...
13073 looking for 6,128 store items on https://guix.example.org..
13074 updating list of substitutes from 'https://guix.example.org'... 100.0%
13075 https://guix.example.org
13076 43.4% substitutes available (2,658 out of 6,128)
13077 7,032.5 MiB of nars (compressed)
13078 19,824.2 MiB on disk (uncompressed)
13079 0.030 seconds per request (182.9 seconds in total)
13080 33.5 requests per second
13082 9.8% (342 out of 3,470) of the missing items are queued
13084 x86_64-linux: 518 (59.7%)
13085 i686-linux: 221 (25.5%)
13086 aarch64-linux: 128 (14.8%)
13087 build rate: 23.41 builds per hour
13088 x86_64-linux: 11.16 builds per hour
13089 i686-linux: 6.03 builds per hour
13090 aarch64-linux: 6.41 builds per hour
13093 @cindex continuous integration, statistics
13094 As you can see, it reports the fraction of all the packages for which
13095 substitutes are available on the server---regardless of whether
13096 substitutes are enabled, and regardless of whether this server's signing
13097 key is authorized. It also reports the size of the compressed archives
13098 (``nars'') provided by the server, the size the corresponding store
13099 items occupy in the store (assuming deduplication is turned off), and
13100 the server's throughput. The second part gives continuous integration
13101 (CI) statistics, if the server supports it. In addition, using the
13102 @option{--coverage} option, @command{guix weather} can list ``important''
13103 package substitutes missing on the server (see below).
13105 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
13106 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
13107 challenge}, it ignores signatures on those substitutes, which is
13108 innocuous since the command only gathers statistics and cannot install
13111 The general syntax is:
13114 guix weather @var{options}@dots{} [@var{packages}@dots{}]
13117 When @var{packages} is omitted, @command{guix weather} checks the availability
13118 of substitutes for @emph{all} the packages, or for those specified with
13119 @option{--manifest}; otherwise it only considers the specified packages. It
13120 is also possible to query specific system types with @option{--system}.
13121 @command{guix weather} exits with a non-zero code when the fraction of
13122 available substitutes is below 100%.
13124 The available options are listed below.
13127 @item --substitute-urls=@var{urls}
13128 @var{urls} is the space-separated list of substitute server URLs to
13129 query. When this option is omitted, the default set of substitute
13130 servers is queried.
13132 @item --system=@var{system}
13133 @itemx -s @var{system}
13134 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
13135 option can be repeated, in which case @command{guix weather} will query
13136 substitutes for several system types.
13138 @item --manifest=@var{file}
13139 Instead of querying substitutes for all the packages, only ask for those
13140 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
13141 with the @code{-m} option of @command{guix package} (@pxref{Invoking
13144 This option can be repeated several times, in which case the manifests
13147 @item --coverage[=@var{count}]
13148 @itemx -c [@var{count}]
13149 Report on substitute coverage for packages: list packages with at least
13150 @var{count} dependents (zero by default) for which substitutes are
13151 unavailable. Dependent packages themselves are not listed: if @var{b} depends
13152 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
13153 @var{b} usually lacks substitutes as well. The result looks like this:
13156 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
13157 computing 8,983 package derivations for x86_64-linux...
13158 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
13159 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
13160 @value{SUBSTITUTE-URL}
13161 64.7% substitutes available (6,047 out of 9,343)
13163 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
13164 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
13165 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
13166 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
13170 What this example shows is that @code{kcoreaddons} and presumably the 58
13171 packages that depend on it have no substitutes at
13172 @code{@value{SUBSTITUTE-SERVER}}; likewise for @code{qgpgme} and the 46
13173 packages that depend on it.
13175 If you are a Guix developer, or if you are taking care of this build farm,
13176 you'll probably want to have a closer look at these packages: they may simply
13179 @item --display-missing
13180 Display the list of store items for which substitutes are missing.
13183 @node Invoking guix processes
13184 @section Invoking @command{guix processes}
13186 The @command{guix processes} command can be useful to developers and system
13187 administrators, especially on multi-user machines and on build farms: it lists
13188 the current sessions (connections to the daemon), as well as information about
13189 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
13190 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
13191 listed.}. Here's an example of the information it returns:
13194 $ sudo guix processes
13197 ClientCommand: guix environment --ad-hoc python
13201 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
13205 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
13206 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
13207 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
13208 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
13210 ChildCommand: guix offload x86_64-linux 7200 1 28800
13212 ChildCommand: guix offload x86_64-linux 7200 1 28800
13214 ChildCommand: guix offload x86_64-linux 7200 1 28800
13217 In this example we see that @command{guix-daemon} has three clients:
13218 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
13219 integration tool; their process identifier (PID) is given by the
13220 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
13221 @command{guix-daemon} sub-process of this particular session.
13223 The @code{LockHeld} fields show which store items are currently locked
13224 by this session, which corresponds to store items being built or
13225 substituted (the @code{LockHeld} field is not displayed when
13226 @command{guix processes} is not running as root). Last, by looking at
13227 the @code{ChildPID} and @code{ChildCommand} fields, we understand that
13228 these three builds are being offloaded (@pxref{Daemon Offload Setup}).
13230 The output is in Recutils format so we can use the handy @command{recsel}
13231 command to select sessions of interest (@pxref{Selection Expressions,,,
13232 recutils, GNU recutils manual}). As an example, the command shows the command
13233 line and PID of the client that triggered the build of a Perl package:
13236 $ sudo guix processes | \
13237 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
13239 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
13242 Additional options are listed below.
13245 @item --format=@var{format}
13246 @itemx -f @var{format}
13247 Produce output in the specified @var{format}, one of:
13251 The default option. It outputs a set of Session recutils records
13252 that include each @code{ChildProcess} as a field.
13255 Normalize the output records into record sets (@pxref{Record Sets,,,
13256 recutils, GNU recutils manual}). Normalizing into record sets allows
13257 joins across record types. The example below lists the PID of each
13258 @code{ChildProcess} and the associated PID for @code{Session} that
13259 spawned the @code{ChildProcess} where the @code{Session} was started
13260 using @command{guix build}.
13263 $ guix processes --format=normalized | \
13267 -p Session.PID,PID \
13268 -e 'Session.ClientCommand ~ "guix build"'
13281 @node System Configuration
13282 @chapter System Configuration
13284 @cindex system configuration
13285 Guix System supports a consistent whole-system configuration
13286 mechanism. By that we mean that all aspects of the global system
13287 configuration---such as the available system services, timezone and
13288 locale settings, user accounts---are declared in a single place. Such
13289 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
13291 One of the advantages of putting all the system configuration under the
13292 control of Guix is that it supports transactional system upgrades, and
13293 makes it possible to roll back to a previous system instantiation,
13294 should something go wrong with the new one (@pxref{Features}). Another
13295 advantage is that it makes it easy to replicate the exact same configuration
13296 across different machines, or at different points in time, without
13297 having to resort to additional administration tools layered on top of
13298 the own tools of the system.
13299 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
13301 This section describes this mechanism. First we focus on the system
13302 administrator's viewpoint---explaining how the system is configured and
13303 instantiated. Then we show how this mechanism can be extended, for
13304 instance to support new system services.
13307 * Using the Configuration System:: Customizing your GNU system.
13308 * operating-system Reference:: Detail of operating-system declarations.
13309 * File Systems:: Configuring file system mounts.
13310 * Mapped Devices:: Block device extra processing.
13311 * User Accounts:: Specifying user accounts.
13312 * Keyboard Layout:: How the system interprets key strokes.
13313 * Locales:: Language and cultural convention settings.
13314 * Services:: Specifying system services.
13315 * Setuid Programs:: Programs running with root privileges.
13316 * X.509 Certificates:: Authenticating HTTPS servers.
13317 * Name Service Switch:: Configuring libc's name service switch.
13318 * Initial RAM Disk:: Linux-Libre bootstrapping.
13319 * Bootloader Configuration:: Configuring the boot loader.
13320 * Invoking guix system:: Instantiating a system configuration.
13321 * Invoking guix deploy:: Deploying a system configuration to a remote host.
13322 * Running Guix in a VM:: How to run Guix System in a virtual machine.
13323 * Defining Services:: Adding new service definitions.
13326 @node Using the Configuration System
13327 @section Using the Configuration System
13329 The operating system is configured by providing an
13330 @code{operating-system} declaration in a file that can then be passed to
13331 the @command{guix system} command (@pxref{Invoking guix system}). A
13332 simple setup, with the default system services, the default Linux-Libre
13333 kernel, initial RAM disk, and boot loader looks like this:
13335 @findex operating-system
13337 @include os-config-bare-bones.texi
13340 This example should be self-describing. Some of the fields defined
13341 above, such as @code{host-name} and @code{bootloader}, are mandatory.
13342 Others, such as @code{packages} and @code{services}, can be omitted, in
13343 which case they get a default value.
13345 Below we discuss the effect of some of the most important fields
13346 (@pxref{operating-system Reference}, for details about all the available
13347 fields), and how to @dfn{instantiate} the operating system using
13348 @command{guix system}.
13350 @unnumberedsubsec Bootloader
13352 @cindex legacy boot, on Intel machines
13353 @cindex BIOS boot, on Intel machines
13356 The @code{bootloader} field describes the method that will be used to boot
13357 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
13358 mode, as in the example above. However, more recent machines rely instead on
13359 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
13360 the @code{bootloader} field should contain something along these lines:
13363 (bootloader-configuration
13364 (bootloader grub-efi-bootloader)
13365 (target "/boot/efi"))
13368 @xref{Bootloader Configuration}, for more information on the available
13369 configuration options.
13371 @unnumberedsubsec Globally-Visible Packages
13373 @vindex %base-packages
13374 The @code{packages} field lists packages that will be globally visible
13375 on the system, for all user accounts---i.e., in every user's @env{PATH}
13376 environment variable---in addition to the per-user profiles
13377 (@pxref{Invoking guix package}). The @code{%base-packages} variable
13378 provides all the tools one would expect for basic user and administrator
13379 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
13380 the GNU Zile lightweight text editor, @command{find}, @command{grep},
13381 etc. The example above adds GNU@tie{}Screen to those,
13382 taken from the @code{(gnu packages screen)}
13383 module (@pxref{Package Modules}). The
13384 @code{(list package output)} syntax can be used to add a specific output
13388 (use-modules (gnu packages))
13389 (use-modules (gnu packages dns))
13393 (packages (cons (list bind "utils")
13397 @findex specification->package
13398 Referring to packages by variable name, like @code{bind} above, has
13399 the advantage of being unambiguous; it also allows typos and such to be
13400 diagnosed right away as ``unbound variables''. The downside is that one
13401 needs to know which module defines which package, and to augment the
13402 @code{use-package-modules} line accordingly. To avoid that, one can use
13403 the @code{specification->package} procedure of the @code{(gnu packages)}
13404 module, which returns the best package for a given name or name and
13408 (use-modules (gnu packages))
13412 (packages (append (map specification->package
13413 '("tcpdump" "htop" "gnupg@@2.0"))
13417 @unnumberedsubsec System Services
13420 @vindex %base-services
13421 The @code{services} field lists @dfn{system services} to be made
13422 available when the system starts (@pxref{Services}).
13423 The @code{operating-system} declaration above specifies that, in
13424 addition to the basic services, we want the OpenSSH secure shell
13425 daemon listening on port 2222 (@pxref{Networking Services,
13426 @code{openssh-service-type}}). Under the hood,
13427 @code{openssh-service-type} arranges so that @command{sshd} is started with the
13428 right command-line options, possibly with supporting configuration files
13429 generated as needed (@pxref{Defining Services}).
13431 @cindex customization, of services
13432 @findex modify-services
13433 Occasionally, instead of using the base services as is, you will want to
13434 customize them. To do this, use @code{modify-services} (@pxref{Service
13435 Reference, @code{modify-services}}) to modify the list.
13437 For example, suppose you want to modify @code{guix-daemon} and Mingetty
13438 (the console log-in) in the @code{%base-services} list (@pxref{Base
13439 Services, @code{%base-services}}). To do that, you can write the
13440 following in your operating system declaration:
13443 (define %my-services
13444 ;; My very own list of services.
13445 (modify-services %base-services
13446 (guix-service-type config =>
13447 (guix-configuration
13449 ;; Fetch substitutes from example.org.
13451 (list "https://example.org/guix"
13452 "https://ci.guix.gnu.org"))))
13453 (mingetty-service-type config =>
13454 (mingetty-configuration
13456 ;; Automatially log in as "guest".
13457 (auto-login "guest")))))
13461 (services %my-services))
13464 This changes the configuration---i.e., the service parameters---of the
13465 @code{guix-service-type} instance, and that of all the
13466 @code{mingetty-service-type} instances in the @code{%base-services} list.
13467 Observe how this is accomplished: first, we arrange for the original
13468 configuration to be bound to the identifier @code{config} in the
13469 @var{body}, and then we write the @var{body} so that it evaluates to the
13470 desired configuration. In particular, notice how we use @code{inherit}
13471 to create a new configuration which has the same values as the old
13472 configuration, but with a few modifications.
13474 @cindex encrypted disk
13475 The configuration for a typical ``desktop'' usage, with an encrypted
13476 root partition, the X11 display
13477 server, GNOME and Xfce (users can choose which of these desktop
13478 environments to use at the log-in screen by pressing @kbd{F1}), network
13479 management, power management, and more, would look like this:
13482 @include os-config-desktop.texi
13485 A graphical system with a choice of lightweight window managers
13486 instead of full-blown desktop environments would look like this:
13489 @include os-config-lightweight-desktop.texi
13492 This example refers to the @file{/boot/efi} file system by its UUID,
13493 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
13494 as returned by the @command{blkid} command.
13496 @xref{Desktop Services}, for the exact list of services provided by
13497 @code{%desktop-services}. @xref{X.509 Certificates}, for background
13498 information about the @code{nss-certs} package that is used here.
13500 Again, @code{%desktop-services} is just a list of service objects. If
13501 you want to remove services from there, you can do so using the
13502 procedures for list filtering (@pxref{SRFI-1 Filtering and
13503 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
13504 following expression returns a list that contains all the services in
13505 @code{%desktop-services} minus the Avahi service:
13508 (remove (lambda (service)
13509 (eq? (service-kind service) avahi-service-type))
13513 @unnumberedsubsec Instantiating the System
13515 Assuming the @code{operating-system} declaration
13516 is stored in the @file{my-system-config.scm}
13517 file, the @command{guix system reconfigure my-system-config.scm} command
13518 instantiates that configuration, and makes it the default GRUB boot
13519 entry (@pxref{Invoking guix system}).
13521 The normal way to change the system configuration is by updating this
13522 file and re-running @command{guix system reconfigure}. One should never
13523 have to touch files in @file{/etc} or to run commands that modify the
13524 system state such as @command{useradd} or @command{grub-install}. In
13525 fact, you must avoid that since that would not only void your warranty
13526 but also prevent you from rolling back to previous versions of your
13527 system, should you ever need to.
13529 @cindex roll-back, of the operating system
13530 Speaking of roll-back, each time you run @command{guix system
13531 reconfigure}, a new @dfn{generation} of the system is created---without
13532 modifying or deleting previous generations. Old system generations get
13533 an entry in the bootloader boot menu, allowing you to boot them in case
13534 something went wrong with the latest generation. Reassuring, no? The
13535 @command{guix system list-generations} command lists the system
13536 generations available on disk. It is also possible to roll back the
13537 system via the commands @command{guix system roll-back} and
13538 @command{guix system switch-generation}.
13540 Although the @command{guix system reconfigure} command will not modify
13541 previous generations, you must take care when the current generation is not
13542 the latest (e.g., after invoking @command{guix system roll-back}), since
13543 the operation might overwrite a later generation (@pxref{Invoking guix
13546 @unnumberedsubsec The Programming Interface
13548 At the Scheme level, the bulk of an @code{operating-system} declaration
13549 is instantiated with the following monadic procedure (@pxref{The Store
13552 @deffn {Monadic Procedure} operating-system-derivation os
13553 Return a derivation that builds @var{os}, an @code{operating-system}
13554 object (@pxref{Derivations}).
13556 The output of the derivation is a single directory that refers to all
13557 the packages, configuration files, and other supporting files needed to
13558 instantiate @var{os}.
13561 This procedure is provided by the @code{(gnu system)} module. Along
13562 with @code{(gnu services)} (@pxref{Services}), this module contains the
13563 guts of Guix System. Make sure to visit it!
13566 @node operating-system Reference
13567 @section @code{operating-system} Reference
13569 This section summarizes all the options available in
13570 @code{operating-system} declarations (@pxref{Using the Configuration
13573 @deftp {Data Type} operating-system
13574 This is the data type representing an operating system configuration.
13575 By that, we mean all the global system configuration, not per-user
13576 configuration (@pxref{Using the Configuration System}).
13579 @item @code{kernel} (default: @code{linux-libre})
13580 The package object of the operating system kernel to
13581 use@footnote{Currently only the Linux-libre kernel is fully supported.
13582 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
13583 available when building a virtual machine disk image.}.
13586 @item @code{hurd} (default: @code{#f})
13587 The package object of the Hurd to be started by the kernel. When this
13588 field is set, produce a GNU/Hurd operating system. In that case,
13589 @code{kernel} must also be set to the @code{gnumach} package---the
13590 microkernel the Hurd runs on.
13593 This feature is experimental and only supported for disk images.
13596 @item @code{kernel-loadable-modules} (default: '())
13597 A list of objects (usually packages) to collect loadable kernel modules
13598 from--e.g. @code{(list ddcci-driver-linux)}.
13600 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
13601 List of strings or gexps representing additional arguments to pass on
13602 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
13604 @item @code{bootloader}
13605 The system bootloader configuration object. @xref{Bootloader Configuration}.
13608 This is the label (a string) as it appears in the bootloader's menu entry.
13609 The default label includes the kernel name and version.
13611 @item @code{keyboard-layout} (default: @code{#f})
13612 This field specifies the keyboard layout to use in the console. It can be
13613 either @code{#f}, in which case the default keyboard layout is used (usually
13614 US English), or a @code{<keyboard-layout>} record. @xref{Keyboard Layout},
13615 for more information.
13617 This keyboard layout is in effect as soon as the kernel has booted. For
13618 instance, it is the keyboard layout in effect when you type a passphrase if
13619 your root file system is on a @code{luks-device-mapping} mapped device
13620 (@pxref{Mapped Devices}).
13623 This does @emph{not} specify the keyboard layout used by the bootloader, nor
13624 that used by the graphical display server. @xref{Bootloader Configuration},
13625 for information on how to specify the bootloader's keyboard layout. @xref{X
13626 Window}, for information on how to specify the keyboard layout used by the X
13630 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
13632 @cindex initial RAM disk
13633 The list of Linux kernel modules that need to be available in the
13634 initial RAM disk. @xref{Initial RAM Disk}.
13636 @item @code{initrd} (default: @code{base-initrd})
13637 A procedure that returns an initial RAM disk for the Linux
13638 kernel. This field is provided to support low-level customization and
13639 should rarely be needed for casual use. @xref{Initial RAM Disk}.
13641 @item @code{firmware} (default: @code{%base-firmware})
13643 List of firmware packages loadable by the operating system kernel.
13645 The default includes firmware needed for Atheros- and Broadcom-based
13646 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
13647 respectively). @xref{Hardware Considerations}, for more info on
13648 supported hardware.
13650 @item @code{host-name}
13653 @item @code{hosts-file}
13655 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
13656 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
13657 Reference Manual}). The default is a file with entries for
13658 @code{localhost} and @var{host-name}.
13660 @item @code{mapped-devices} (default: @code{'()})
13661 A list of mapped devices. @xref{Mapped Devices}.
13663 @item @code{file-systems}
13664 A list of file systems. @xref{File Systems}.
13666 @cindex swap devices
13668 @item @code{swap-devices} (default: @code{'()})
13669 A list of UUIDs, file system labels, or strings identifying devices or
13670 files to be used for ``swap
13671 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
13672 Manual}). Here are some examples:
13675 @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
13676 Use the swap partition with the given UUID@. You can learn the UUID of a
13677 Linux swap partition by running @command{swaplabel @var{device}}, where
13678 @var{device} is the @file{/dev} file name of that partition.
13680 @item (list (file-system-label "swap"))
13681 Use the partition with label @code{swap}. Again, the
13682 @command{swaplabel} command allows you to view and change the label of a
13683 Linux swap partition.
13685 @item (list "/swapfile")
13686 Use the file @file{/swapfile} as swap space.
13688 @item (list "/dev/sda3" "/dev/sdb2")
13689 Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
13690 We recommend referring to swap devices by UUIDs or labels as shown above
13694 It is possible to specify a swap file in a file system on a mapped
13695 device (under @file{/dev/mapper}), provided that the necessary device
13696 mapping and file system are also specified. @xref{Mapped Devices} and
13697 @ref{File Systems}.
13699 @item @code{users} (default: @code{%base-user-accounts})
13700 @itemx @code{groups} (default: @code{%base-groups})
13701 List of user accounts and groups. @xref{User Accounts}.
13703 If the @code{users} list lacks a user account with UID@tie{}0, a
13704 ``root'' account with UID@tie{}0 is automatically added.
13706 @item @code{skeletons} (default: @code{(default-skeletons)})
13707 A list of target file name/file-like object tuples (@pxref{G-Expressions,
13708 file-like objects}). These are the skeleton files that will be added to
13709 the home directory of newly-created user accounts.
13711 For instance, a valid value may look like this:
13714 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
13715 (".guile" ,(plain-file "guile"
13716 "(use-modules (ice-9 readline))
13717 (activate-readline)")))
13720 @item @code{issue} (default: @code{%default-issue})
13721 A string denoting the contents of the @file{/etc/issue} file, which is
13722 displayed when users log in on a text console.
13724 @item @code{packages} (default: @code{%base-packages})
13725 A list of packages to be installed in the global profile, which is accessible
13726 at @file{/run/current-system/profile}. Each element is either a package
13727 variable or a package/output tuple. Here's a simple example of both:
13730 (cons* git ; the default "out" output
13731 (list git "send-email") ; another output of git
13732 %base-packages) ; the default set
13735 The default set includes core utilities and it is good practice to
13736 install non-core utilities in user profiles (@pxref{Invoking guix
13739 @item @code{timezone}
13740 A timezone identifying string---e.g., @code{"Europe/Paris"}.
13742 You can run the @command{tzselect} command to find out which timezone
13743 string corresponds to your region. Choosing an invalid timezone name
13744 causes @command{guix system} to fail.
13746 @item @code{locale} (default: @code{"en_US.utf8"})
13747 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
13748 Library Reference Manual}). @xref{Locales}, for more information.
13750 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
13751 The list of locale definitions to be compiled and that may be used at
13752 run time. @xref{Locales}.
13754 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
13755 The list of GNU@tie{}libc packages whose locale data and tools are used
13756 to build the locale definitions. @xref{Locales}, for compatibility
13757 considerations that justify this option.
13759 @item @code{name-service-switch} (default: @code{%default-nss})
13760 Configuration of the libc name service switch (NSS)---a
13761 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
13764 @item @code{services} (default: @code{%base-services})
13765 A list of service objects denoting system services. @xref{Services}.
13767 @cindex essential services
13768 @item @code{essential-services} (default: ...)
13769 The list of ``essential services''---i.e., things like instances of
13770 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
13771 Reference}), which are derived from the operating system definition itself.
13772 As a user you should @emph{never} need to touch this field.
13774 @item @code{pam-services} (default: @code{(base-pam-services)})
13776 @cindex pluggable authentication modules
13777 Linux @dfn{pluggable authentication module} (PAM) services.
13778 @c FIXME: Add xref to PAM services section.
13780 @item @code{setuid-programs} (default: @code{%setuid-programs})
13781 List of string-valued G-expressions denoting setuid programs.
13782 @xref{Setuid Programs}.
13784 @item @code{sudoers-file} (default: @code{%sudoers-specification})
13785 @cindex sudoers file
13786 The contents of the @file{/etc/sudoers} file as a file-like object
13787 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
13789 This file specifies which users can use the @command{sudo} command, what
13790 they are allowed to do, and what privileges they may gain. The default
13791 is that only @code{root} and members of the @code{wheel} group may use
13796 @deffn {Scheme Syntax} this-operating-system
13797 When used in the @emph{lexical scope} of an operating system field definition,
13798 this identifier resolves to the operating system being defined.
13800 The example below shows how to refer to the operating system being defined in
13801 the definition of the @code{label} field:
13804 (use-modules (gnu) (guix))
13808 (label (package-full-name
13809 (operating-system-kernel this-operating-system))))
13812 It is an error to refer to @code{this-operating-system} outside an operating
13819 @section File Systems
13821 The list of file systems to be mounted is specified in the
13822 @code{file-systems} field of the operating system declaration
13823 (@pxref{Using the Configuration System}). Each file system is declared
13824 using the @code{file-system} form, like this:
13828 (mount-point "/home")
13829 (device "/dev/sda3")
13833 As usual, some of the fields are mandatory---those shown in the example
13834 above---while others can be omitted. These are described below.
13836 @deftp {Data Type} file-system
13837 Objects of this type represent file systems to be mounted. They
13838 contain the following members:
13842 This is a string specifying the type of the file system---e.g.,
13845 @item @code{mount-point}
13846 This designates the place where the file system is to be mounted.
13848 @item @code{device}
13849 This names the ``source'' of the file system. It can be one of three
13850 things: a file system label, a file system UUID, or the name of a
13851 @file{/dev} node. Labels and UUIDs offer a way to refer to file
13852 systems without having to hard-code their actual device
13853 name@footnote{Note that, while it is tempting to use
13854 @file{/dev/disk/by-uuid} and similar device names to achieve the same
13855 result, this is not recommended: These special device nodes are created
13856 by the udev daemon and may be unavailable at the time the device is
13859 @findex file-system-label
13860 File system labels are created using the @code{file-system-label}
13861 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
13862 plain strings. Here's an example of a file system referred to by its
13863 label, as shown by the @command{e2label} command:
13867 (mount-point "/home")
13869 (device (file-system-label "my-home")))
13873 UUIDs are converted from their string representation (as shown by the
13874 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
13875 @code{uuid} form expects 16-byte UUIDs as defined in
13876 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
13877 form of UUID used by the ext2 family of file systems and others, but it
13878 is different from ``UUIDs'' found in FAT file systems, for instance.},
13883 (mount-point "/home")
13885 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
13888 When the source of a file system is a mapped device (@pxref{Mapped
13889 Devices}), its @code{device} field @emph{must} refer to the mapped
13890 device name---e.g., @file{"/dev/mapper/root-partition"}.
13891 This is required so that
13892 the system knows that mounting the file system depends on having the
13893 corresponding device mapping established.
13895 @item @code{flags} (default: @code{'()})
13896 This is a list of symbols denoting mount flags. Recognized flags
13897 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
13898 access to special files), @code{no-suid} (ignore setuid and setgid
13899 bits), @code{no-atime} (do not update file access times),
13900 @code{strict-atime} (update file access time), @code{lazy-time} (only
13901 update time on the in-memory version of the file inode), and
13902 @code{no-exec} (disallow program execution).
13903 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
13904 Manual}, for more information on these flags.
13906 @item @code{options} (default: @code{#f})
13907 This is either @code{#f}, or a string denoting mount options passed to
13908 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
13909 Library Reference Manual}, for details and run @command{man 8 mount} for
13910 options for various file systems. Note that the
13911 @code{file-system-options->alist} and @code{alist->file-system-options}
13912 procedures from @code{(gnu system file-systems)} can be used to convert
13913 file system options given as an association list to the string
13914 representation, and vice-versa.
13916 @item @code{mount?} (default: @code{#t})
13917 This value indicates whether to automatically mount the file system when
13918 the system is brought up. When set to @code{#f}, the file system gets
13919 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
13920 is not automatically mounted.
13922 @item @code{needed-for-boot?} (default: @code{#f})
13923 This Boolean value indicates whether the file system is needed when
13924 booting. If that is true, then the file system is mounted when the
13925 initial RAM disk (initrd) is loaded. This is always the case, for
13926 instance, for the root file system.
13928 @item @code{check?} (default: @code{#t})
13929 This Boolean indicates whether the file system needs to be checked for
13930 errors before being mounted.
13932 @item @code{create-mount-point?} (default: @code{#f})
13933 When true, the mount point is created if it does not exist yet.
13935 @item @code{mount-may-fail?} (default: @code{#f})
13936 When true, this indicates that mounting this file system can fail but
13937 that should not be considered an error. This is useful in unusual
13938 cases; an example of this is @code{efivarfs}, a file system that can
13939 only be mounted on EFI/UEFI systems.
13941 @item @code{dependencies} (default: @code{'()})
13942 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
13943 representing file systems that must be mounted or mapped devices that
13944 must be opened before (and unmounted or closed after) this one.
13946 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
13947 a dependency of @file{/sys/fs/cgroup/cpu} and
13948 @file{/sys/fs/cgroup/memory}.
13950 Another example is a file system that depends on a mapped device, for
13951 example for an encrypted partition (@pxref{Mapped Devices}).
13955 @deffn {Scheme Procedure} file-system-label @var{str}
13956 This procedure returns an opaque file system label from @var{str}, a
13960 (file-system-label "home")
13961 @result{} #<file-system-label "home">
13964 File system labels are used to refer to file systems by label rather
13965 than by device name. See above for examples.
13968 The @code{(gnu system file-systems)} exports the following useful
13971 @defvr {Scheme Variable} %base-file-systems
13972 These are essential file systems that are required on normal systems,
13973 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
13974 below). Operating system declarations should always contain at least
13978 @defvr {Scheme Variable} %pseudo-terminal-file-system
13979 This is the file system to be mounted as @file{/dev/pts}. It supports
13980 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
13981 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
13982 Manual}). Pseudo-terminals are used by terminal emulators such as
13986 @defvr {Scheme Variable} %shared-memory-file-system
13987 This file system is mounted as @file{/dev/shm} and is used to support
13988 memory sharing across processes (@pxref{Memory-mapped I/O,
13989 @code{shm_open},, libc, The GNU C Library Reference Manual}).
13992 @defvr {Scheme Variable} %immutable-store
13993 This file system performs a read-only ``bind mount'' of
13994 @file{/gnu/store}, making it read-only for all the users including
13995 @code{root}. This prevents against accidental modification by software
13996 running as @code{root} or by system administrators.
13998 The daemon itself is still able to write to the store: it remounts it
13999 read-write in its own ``name space.''
14002 @defvr {Scheme Variable} %binary-format-file-system
14003 The @code{binfmt_misc} file system, which allows handling of arbitrary
14004 executable file types to be delegated to user space. This requires the
14005 @code{binfmt.ko} kernel module to be loaded.
14008 @defvr {Scheme Variable} %fuse-control-file-system
14009 The @code{fusectl} file system, which allows unprivileged users to mount
14010 and unmount user-space FUSE file systems. This requires the
14011 @code{fuse.ko} kernel module to be loaded.
14014 The @code{(gnu system uuid)} module provides tools to deal with file
14015 system ``unique identifiers'' (UUIDs).
14017 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
14018 Return an opaque UUID (unique identifier) object of the given @var{type}
14019 (a symbol) by parsing @var{str} (a string):
14022 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
14023 @result{} #<<uuid> type: dce bv: @dots{}>
14025 (uuid "1234-ABCD" 'fat)
14026 @result{} #<<uuid> type: fat bv: @dots{}>
14029 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
14030 @code{ntfs}, or one of the commonly found synonyms for these.
14032 UUIDs are another way to unambiguously refer to file systems in
14033 operating system configuration. See the examples above.
14037 @node Btrfs file system
14038 @subsection Btrfs file system
14040 The Btrfs has special features, such as subvolumes, that merit being
14041 explained in more details. The following section attempts to cover
14042 basic as well as complex uses of a Btrfs file system with the Guix
14045 In its simplest usage, a Btrfs file system can be described, for
14050 (mount-point "/home")
14052 (device (file-system-label "my-home")))
14055 The example below is more complex, as it makes use of a Btrfs
14056 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
14057 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
14058 dependency on @code{mapped-devices}):
14062 (device (file-system-label "my-btrfs-pool"))
14065 (options "subvol=rootfs")
14066 (dependencies mapped-devices))
14069 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
14070 top level during the early boot, and rely on their configuration to
14071 refer to the correct subvolume path within that top level. The
14072 bootloaders operating in this way typically produce their configuration
14073 on a running system where the Btrfs partitions are already mounted and
14074 where the subvolume information is readily available. As an example,
14075 @command{grub-mkconfig}, the configuration generator command shipped
14076 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
14077 path of a subvolume.
14079 The Guix System produces a bootloader configuration using the operating
14080 system configuration as its sole input; it is therefore necessary to
14081 extract the subvolume name on which @file{/gnu/store} lives (if any)
14082 from that operating system configuration. To better illustrate,
14083 consider a subvolume named 'rootfs' which contains the root file system
14084 data. In such situation, the GRUB bootloader would only see the top
14085 level of the root Btrfs partition, e.g.:
14089 ├── rootfs (subvolume directory)
14090 ├── gnu (normal directory)
14091 ├── store (normal directory)
14095 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
14096 of the kernel, initrd binaries and any other files referred to in the
14097 GRUB configuration that must be found during the early boot.
14099 The next example shows a nested hierarchy of subvolumes and
14104 ├── rootfs (subvolume)
14105 ├── gnu (normal directory)
14106 ├── store (subvolume)
14110 This scenario would work without mounting the 'store' subvolume.
14111 Mounting 'rootfs' is sufficient, since the subvolume name matches its
14112 intended mount point in the file system hierarchy. Alternatively, the
14113 'store' subvolume could be referred to by setting the @code{subvol}
14114 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
14116 Finally, a more contrived example of nested subvolumes:
14120 ├── root-snapshots (subvolume)
14121 ├── root-current (subvolume)
14122 ├── guix-store (subvolume)
14126 Here, the 'guix-store' subvolume doesn't match its intended mount point,
14127 so it is necessary to mount it. The subvolume must be fully specified,
14128 by passing its file name to the @code{subvol} option. To illustrate,
14129 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
14130 a file system declaration such as:
14134 (device (file-system-label "btrfs-pool-1"))
14135 (mount-point "/gnu/store")
14137 (options "subvol=root-snapshots/root-current/guix-store,\
14138 compress-force=zstd,space_cache=v2"))
14141 @node Mapped Devices
14142 @section Mapped Devices
14144 @cindex device mapping
14145 @cindex mapped devices
14146 The Linux kernel has a notion of @dfn{device mapping}: a block device,
14147 such as a hard disk partition, can be @dfn{mapped} into another device,
14148 usually in @code{/dev/mapper/},
14149 with additional processing over the data that flows through
14150 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
14151 concept of a ``mapped device'' and that of a file system: both boil down
14152 to @emph{translating} input/output operations made on a file to
14153 operations on its backing store. Thus, the Hurd implements mapped
14154 devices, like file systems, using the generic @dfn{translator} mechanism
14155 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
14156 typical example is encryption device mapping: all writes to the mapped
14157 device are encrypted, and all reads are deciphered, transparently.
14158 Guix extends this notion by considering any device or set of devices that
14159 are @dfn{transformed} in some way to create a new device; for instance,
14160 RAID devices are obtained by @dfn{assembling} several other devices, such
14161 as hard disks or partitions, into a new one that behaves as one partition.
14163 Mapped devices are declared using the @code{mapped-device} form,
14164 defined as follows; for examples, see below.
14166 @deftp {Data Type} mapped-device
14167 Objects of this type represent device mappings that will be made when
14168 the system boots up.
14172 This is either a string specifying the name of the block device to be mapped,
14173 such as @code{"/dev/sda3"}, or a list of such strings when several devices
14174 need to be assembled for creating a new one. In case of LVM this is a
14175 string specifying name of the volume group to be mapped.
14178 This string specifies the name of the resulting mapped device. For
14179 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
14180 specifying @code{"my-partition"} leads to the creation of
14181 the @code{"/dev/mapper/my-partition"} device.
14182 For RAID devices of type @code{raid-device-mapping}, the full device name
14183 such as @code{"/dev/md0"} needs to be given.
14184 LVM logical volumes of type @code{lvm-device-mapping} need to
14185 be specified as @code{"VGNAME-LVNAME"}.
14188 This list of strings specifies names of the resulting mapped devices in case
14189 there are several. The format is identical to @var{target}.
14192 This must be a @code{mapped-device-kind} object, which specifies how
14193 @var{source} is mapped to @var{target}.
14197 @defvr {Scheme Variable} luks-device-mapping
14198 This defines LUKS block device encryption using the @command{cryptsetup}
14199 command from the package with the same name. It relies on the
14200 @code{dm-crypt} Linux kernel module.
14203 @defvr {Scheme Variable} raid-device-mapping
14204 This defines a RAID device, which is assembled using the @code{mdadm}
14205 command from the package with the same name. It requires a Linux kernel
14206 module for the appropriate RAID level to be loaded, such as @code{raid456}
14207 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
14210 @cindex LVM, logical volume manager
14211 @defvr {Scheme Variable} lvm-device-mapping
14212 This defines one or more logical volumes for the Linux
14213 @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
14214 The volume group is activated by the @command{vgchange} command from the
14215 @code{lvm2} package.
14218 @cindex disk encryption
14220 The following example specifies a mapping from @file{/dev/sda3} to
14221 @file{/dev/mapper/home} using LUKS---the
14222 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
14223 standard mechanism for disk encryption.
14224 The @file{/dev/mapper/home}
14225 device can then be used as the @code{device} of a @code{file-system}
14226 declaration (@pxref{File Systems}).
14230 (source "/dev/sda3")
14232 (type luks-device-mapping))
14235 Alternatively, to become independent of device numbering, one may obtain
14236 the LUKS UUID (@dfn{unique identifier}) of the source device by a
14240 cryptsetup luksUUID /dev/sda3
14243 and use it as follows:
14247 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
14249 (type luks-device-mapping))
14252 @cindex swap encryption
14253 It is also desirable to encrypt swap space, since swap space may contain
14254 sensitive data. One way to accomplish that is to use a swap file in a
14255 file system on a device mapped via LUKS encryption. In this way, the
14256 swap file is encrypted because the entire device is encrypted.
14257 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
14259 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
14260 may be declared as follows:
14264 (source (list "/dev/sda1" "/dev/sdb1"))
14265 (target "/dev/md0")
14266 (type raid-device-mapping))
14269 The @file{/dev/md0} device can then be used as the @code{device} of a
14270 @code{file-system} declaration (@pxref{File Systems}).
14271 Note that the RAID level need not be given; it is chosen during the
14272 initial creation and formatting of the RAID device and is determined
14273 automatically later.
14275 LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
14276 be declared as follows:
14281 (targets (list "vg0-alpha" "vg0-beta"))
14282 (type lvm-device-mapping))
14285 Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
14286 then be used as the @code{device} of a @code{file-system} declaration
14287 (@pxref{File Systems}).
14289 @node User Accounts
14290 @section User Accounts
14294 @cindex user accounts
14295 User accounts and groups are entirely managed through the
14296 @code{operating-system} declaration. They are specified with the
14297 @code{user-account} and @code{user-group} forms:
14303 (supplementary-groups '("wheel" ;allow use of sudo, etc.
14304 "audio" ;sound card
14305 "video" ;video devices such as webcams
14306 "cdrom")) ;the good ol' CD-ROM
14307 (comment "Bob's sister"))
14310 Here's a user account that uses a different shell and a custom home
14311 directory (the default would be @file{"/home/bob"}):
14317 (comment "Alice's bro")
14318 (shell (file-append zsh "/bin/zsh"))
14319 (home-directory "/home/robert"))
14322 When booting or upon completion of @command{guix system reconfigure},
14323 the system ensures that only the user accounts and groups specified in
14324 the @code{operating-system} declaration exist, and with the specified
14325 properties. Thus, account or group creations or modifications made by
14326 directly invoking commands such as @command{useradd} are lost upon
14327 reconfiguration or reboot. This ensures that the system remains exactly
14330 @deftp {Data Type} user-account
14331 Objects of this type represent user accounts. The following members may
14336 The name of the user account.
14340 This is the name (a string) or identifier (a number) of the user group
14341 this account belongs to.
14343 @item @code{supplementary-groups} (default: @code{'()})
14344 Optionally, this can be defined as a list of group names that this
14345 account belongs to.
14347 @item @code{uid} (default: @code{#f})
14348 This is the user ID for this account (a number), or @code{#f}. In the
14349 latter case, a number is automatically chosen by the system when the
14350 account is created.
14352 @item @code{comment} (default: @code{""})
14353 A comment about the account, such as the account owner's full name.
14355 @item @code{home-directory}
14356 This is the name of the home directory for the account.
14358 @item @code{create-home-directory?} (default: @code{#t})
14359 Indicates whether the home directory of this account should be created
14360 if it does not exist yet.
14362 @item @code{shell} (default: Bash)
14363 This is a G-expression denoting the file name of a program to be used as
14364 the shell (@pxref{G-Expressions}). For example, you would refer to the
14365 Bash executable like this:
14368 (file-append bash "/bin/bash")
14372 ... and to the Zsh executable like that:
14375 (file-append zsh "/bin/zsh")
14378 @item @code{system?} (default: @code{#f})
14379 This Boolean value indicates whether the account is a ``system''
14380 account. System accounts are sometimes treated specially; for instance,
14381 graphical login managers do not list them.
14383 @anchor{user-account-password}
14384 @cindex password, for user accounts
14385 @item @code{password} (default: @code{#f})
14386 You would normally leave this field to @code{#f}, initialize user
14387 passwords as @code{root} with the @command{passwd} command, and then let
14388 users change it with @command{passwd}. Passwords set with
14389 @command{passwd} are of course preserved across reboot and
14392 If you @emph{do} want to set an initial password for an account, then
14393 this field must contain the encrypted password, as a string. You can use the
14394 @code{crypt} procedure for this purpose:
14401 ;; Specify a SHA-512-hashed initial password.
14402 (password (crypt "InitialPassword!" "$6$abc")))
14406 The hash of this initial password will be available in a file in
14407 @file{/gnu/store}, readable by all the users, so this method must be used with
14411 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
14412 more information on password encryption, and @ref{Encryption,,, guile, GNU
14413 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
14419 User group declarations are even simpler:
14422 (user-group (name "students"))
14425 @deftp {Data Type} user-group
14426 This type is for, well, user groups. There are just a few fields:
14430 The name of the group.
14432 @item @code{id} (default: @code{#f})
14433 The group identifier (a number). If @code{#f}, a new number is
14434 automatically allocated when the group is created.
14436 @item @code{system?} (default: @code{#f})
14437 This Boolean value indicates whether the group is a ``system'' group.
14438 System groups have low numerical IDs.
14440 @item @code{password} (default: @code{#f})
14441 What, user groups can have a password? Well, apparently yes. Unless
14442 @code{#f}, this field specifies the password of the group.
14447 For convenience, a variable lists all the basic user groups one may
14450 @defvr {Scheme Variable} %base-groups
14451 This is the list of basic user groups that users and/or packages expect
14452 to be present on the system. This includes groups such as ``root'',
14453 ``wheel'', and ``users'', as well as groups used to control access to
14454 specific devices such as ``audio'', ``disk'', and ``cdrom''.
14457 @defvr {Scheme Variable} %base-user-accounts
14458 This is the list of basic system accounts that programs may expect to
14459 find on a GNU/Linux system, such as the ``nobody'' account.
14461 Note that the ``root'' account is not included here. It is a
14462 special-case and is automatically added whether or not it is specified.
14465 @node Keyboard Layout
14466 @section Keyboard Layout
14468 @cindex keyboard layout
14470 To specify what each key of your keyboard does, you need to tell the operating
14471 system what @dfn{keyboard layout} you want to use. The default, when nothing
14472 is specified, is the US English QWERTY layout for 105-key PC keyboards.
14473 However, German speakers will usually prefer the German QWERTZ layout, French
14474 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
14475 or bépo, and they might even want to further customize the effect of some of
14476 the keys. This section explains how to get that done.
14478 @cindex keyboard layout, definition
14479 There are three components that will want to know about your keyboard layout:
14483 The @emph{bootloader} may want to know what keyboard layout you want to use
14484 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
14485 you want, for instance, to make sure that you can type the passphrase of your
14486 encrypted root partition using the right layout.
14489 The @emph{operating system kernel}, Linux, will need that so that the console
14490 is properly configured (@pxref{operating-system Reference,
14491 @code{keyboard-layout}}).
14494 The @emph{graphical display server}, usually Xorg, also has its own idea of
14495 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
14498 Guix allows you to configure all three separately but, fortunately, it allows
14499 you to share the same keyboard layout for all three components.
14501 @cindex XKB, keyboard layouts
14502 Keyboard layouts are represented by records created by the
14503 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
14504 the X Keyboard extension (XKB), each layout has four attributes: a name (often
14505 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
14506 optional variant name, an optional keyboard model name, and a possibly empty
14507 list of additional options. In most cases the layout name is all you care
14510 @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
14511 [#:model] [#:options '()]
14512 Return a new keyboard layout with the given @var{name} and @var{variant}.
14514 @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
14515 string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
14516 @code{xkeyboard-config} package for valid options.
14519 Here are a few examples:
14522 ;; The German QWERTZ layout. Here we assume a standard
14523 ;; "pc105" keyboard model.
14524 (keyboard-layout "de")
14526 ;; The bépo variant of the French layout.
14527 (keyboard-layout "fr" "bepo")
14529 ;; The Catalan layout.
14530 (keyboard-layout "es" "cat")
14532 ;; Arabic layout with "Alt-Shift" to switch to US layout.
14533 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
14535 ;; The Latin American Spanish layout. In addition, the
14536 ;; "Caps Lock" key is used as an additional "Ctrl" key,
14537 ;; and the "Menu" key is used as a "Compose" key to enter
14538 ;; accented letters.
14539 (keyboard-layout "latam"
14540 #:options '("ctrl:nocaps" "compose:menu"))
14542 ;; The Russian layout for a ThinkPad keyboard.
14543 (keyboard-layout "ru" #:model "thinkpad")
14545 ;; The "US international" layout, which is the US layout plus
14546 ;; dead keys to enter accented characters. This is for an
14547 ;; Apple MacBook keyboard.
14548 (keyboard-layout "us" "intl" #:model "macbook78")
14551 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
14552 for a complete list of supported layouts, variants, and models.
14554 @cindex keyboard layout, configuration
14555 Let's say you want your system to use the Turkish keyboard layout throughout
14556 your system---bootloader, console, and Xorg. Here's what your system
14557 configuration would look like:
14559 @findex set-xorg-configuration
14561 ;; Using the Turkish layout for the bootloader, the console,
14566 (keyboard-layout (keyboard-layout "tr")) ;for the console
14567 (bootloader (bootloader-configuration
14568 (bootloader grub-efi-bootloader)
14569 (target "/boot/efi")
14570 (keyboard-layout keyboard-layout))) ;for GRUB
14571 (services (cons (set-xorg-configuration
14572 (xorg-configuration ;for Xorg
14573 (keyboard-layout keyboard-layout)))
14574 %desktop-services)))
14577 In the example above, for GRUB and for Xorg, we just refer to the
14578 @code{keyboard-layout} field defined above, but we could just as well refer to
14579 a different layout. The @code{set-xorg-configuration} procedure communicates
14580 the desired Xorg configuration to the graphical log-in manager, by default
14583 We've discussed how to specify the @emph{default} keyboard layout of your
14584 system when it starts, but you can also adjust it at run time:
14588 If you're using GNOME, its settings panel has a ``Region & Language'' entry
14589 where you can select one or more keyboard layouts.
14592 Under Xorg, the @command{setxkbmap} command (from the same-named package)
14593 allows you to change the current layout. For example, this is how you would
14594 change the layout to US Dvorak:
14597 setxkbmap us dvorak
14601 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
14602 console. However, note that @code{loadkeys} does @emph{not} use the XKB
14603 keyboard layout categorization described above. The command below loads the
14604 French bépo layout:
14615 A @dfn{locale} defines cultural conventions for a particular language
14616 and region of the world (@pxref{Locales,,, libc, The GNU C Library
14617 Reference Manual}). Each locale has a name that typically has the form
14618 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
14619 @code{fr_LU.utf8} designates the locale for the French language, with
14620 cultural conventions from Luxembourg, and using the UTF-8 encoding.
14622 @cindex locale definition
14623 Usually, you will want to specify the default locale for the machine
14624 using the @code{locale} field of the @code{operating-system} declaration
14625 (@pxref{operating-system Reference, @code{locale}}).
14627 The selected locale is automatically added to the @dfn{locale
14628 definitions} known to the system if needed, with its codeset inferred
14629 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
14630 @code{UTF-8} codeset. Additional locale definitions can be specified in
14631 the @code{locale-definitions} slot of @code{operating-system}---this is
14632 useful, for instance, if the codeset could not be inferred from the
14633 locale name. The default set of locale definitions includes some widely
14634 used locales, but not all the available locales, in order to save space.
14636 For instance, to add the North Frisian locale for Germany, the value of
14640 (cons (locale-definition
14641 (name "fy_DE.utf8") (source "fy_DE"))
14642 %default-locale-definitions)
14645 Likewise, to save space, one might want @code{locale-definitions} to
14646 list only the locales that are actually used, as in:
14649 (list (locale-definition
14650 (name "ja_JP.eucjp") (source "ja_JP")
14651 (charset "EUC-JP")))
14655 The compiled locale definitions are available at
14656 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
14657 version, which is the default location where the GNU@tie{}libc provided
14658 by Guix looks for locale data. This can be overridden using the
14659 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
14660 @env{LOCPATH} and locale packages}).
14662 The @code{locale-definition} form is provided by the @code{(gnu system
14663 locale)} module. Details are given below.
14665 @deftp {Data Type} locale-definition
14666 This is the data type of a locale definition.
14671 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
14672 Reference Manual}, for more information on locale names.
14674 @item @code{source}
14675 The name of the source for that locale. This is typically the
14676 @code{@var{language}_@var{territory}} part of the locale name.
14678 @item @code{charset} (default: @code{"UTF-8"})
14679 The ``character set'' or ``code set'' for that locale,
14680 @uref{https://www.iana.org/assignments/character-sets, as defined by
14686 @defvr {Scheme Variable} %default-locale-definitions
14687 A list of commonly used UTF-8 locales, used as the default
14688 value of the @code{locale-definitions} field of @code{operating-system}
14691 @cindex locale name
14692 @cindex normalized codeset in locale names
14693 These locale definitions use the @dfn{normalized codeset} for the part
14694 that follows the dot in the name (@pxref{Using gettextized software,
14695 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
14696 instance it has @code{uk_UA.utf8} but @emph{not}, say,
14697 @code{uk_UA.UTF-8}.
14700 @subsection Locale Data Compatibility Considerations
14702 @cindex incompatibility, of locale data
14703 @code{operating-system} declarations provide a @code{locale-libcs} field
14704 to specify the GNU@tie{}libc packages that are used to compile locale
14705 declarations (@pxref{operating-system Reference}). ``Why would I
14706 care?'', you may ask. Well, it turns out that the binary format of
14707 locale data is occasionally incompatible from one libc version to
14710 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
14711 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
14712 For instance, a program linked against libc version 2.21 is unable to
14713 read locale data produced with libc 2.22; worse, that program
14714 @emph{aborts} instead of simply ignoring the incompatible locale
14715 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
14716 the incompatible locale data, which is already an improvement.}.
14717 Similarly, a program linked against libc 2.22 can read most, but not
14718 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
14719 data is incompatible); thus calls to @code{setlocale} may fail, but
14720 programs will not abort.
14722 The ``problem'' with Guix is that users have a lot of freedom: They can
14723 choose whether and when to upgrade software in their profiles, and might
14724 be using a libc version different from the one the system administrator
14725 used to build the system-wide locale data.
14727 Fortunately, unprivileged users can also install their own locale data
14728 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
14729 @env{GUIX_LOCPATH} and locale packages}).
14731 Still, it is best if the system-wide locale data at
14732 @file{/run/current-system/locale} is built for all the libc versions
14733 actually in use on the system, so that all the programs can access
14734 it---this is especially crucial on a multi-user system. To do that, the
14735 administrator can specify several libc packages in the
14736 @code{locale-libcs} field of @code{operating-system}:
14739 (use-package-modules base)
14743 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
14746 This example would lead to a system containing locale definitions for
14747 both libc 2.21 and the current version of libc in
14748 @file{/run/current-system/locale}.
14754 @cindex system services
14755 An important part of preparing an @code{operating-system} declaration is
14756 listing @dfn{system services} and their configuration (@pxref{Using the
14757 Configuration System}). System services are typically daemons launched
14758 when the system boots, or other actions needed at that time---e.g.,
14759 configuring network access.
14761 Guix has a broad definition of ``service'' (@pxref{Service
14762 Composition}), but many services are managed by the GNU@tie{}Shepherd
14763 (@pxref{Shepherd Services}). On a running system, the @command{herd}
14764 command allows you to list the available services, show their status,
14765 start and stop them, or do other specific operations (@pxref{Jump
14766 Start,,, shepherd, The GNU Shepherd Manual}). For example:
14772 The above command, run as @code{root}, lists the currently defined
14773 services. The @command{herd doc} command shows a synopsis of the given
14774 service and its associated actions:
14778 Run libc's name service cache daemon (nscd).
14780 # herd doc nscd action invalidate
14781 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
14784 The @command{start}, @command{stop}, and @command{restart} sub-commands
14785 have the effect you would expect. For instance, the commands below stop
14786 the nscd service and restart the Xorg display server:
14790 Service nscd has been stopped.
14791 # herd restart xorg-server
14792 Service xorg-server has been stopped.
14793 Service xorg-server has been started.
14796 The following sections document the available services, starting with
14797 the core services, that may be used in an @code{operating-system}
14801 * Base Services:: Essential system services.
14802 * Scheduled Job Execution:: The mcron service.
14803 * Log Rotation:: The rottlog service.
14804 * Networking Services:: Network setup, SSH daemon, etc.
14805 * Unattended Upgrades:: Automated system upgrades.
14806 * X Window:: Graphical display.
14807 * Printing Services:: Local and remote printer support.
14808 * Desktop Services:: D-Bus and desktop services.
14809 * Sound Services:: ALSA and Pulseaudio services.
14810 * Database Services:: SQL databases, key-value stores, etc.
14811 * Mail Services:: IMAP, POP3, SMTP, and all that.
14812 * Messaging Services:: Messaging services.
14813 * Telephony Services:: Telephony services.
14814 * File-Sharing Services:: File-sharing services.
14815 * Monitoring Services:: Monitoring services.
14816 * Kerberos Services:: Kerberos services.
14817 * LDAP Services:: LDAP services.
14818 * Web Services:: Web servers.
14819 * Certificate Services:: TLS certificates via Let's Encrypt.
14820 * DNS Services:: DNS daemons.
14821 * VPN Services:: VPN daemons.
14822 * Network File System:: NFS related services.
14823 * Continuous Integration:: The Cuirass service.
14824 * Power Management Services:: Extending battery life.
14825 * Audio Services:: The MPD.
14826 * Virtualization Services:: Virtualization services.
14827 * Version Control Services:: Providing remote access to Git repositories.
14828 * Game Services:: Game servers.
14829 * PAM Mount Service:: Service to mount volumes when logging in.
14830 * Guix Services:: Services relating specifically to Guix.
14831 * Linux Services:: Services tied to the Linux kernel.
14832 * Hurd Services:: Services specific for a Hurd System.
14833 * Miscellaneous Services:: Other services.
14836 @node Base Services
14837 @subsection Base Services
14839 The @code{(gnu services base)} module provides definitions for the basic
14840 services that one expects from the system. The services exported by
14841 this module are listed below.
14843 @defvr {Scheme Variable} %base-services
14844 This variable contains a list of basic services (@pxref{Service Types
14845 and Services}, for more information on service objects) one would
14846 expect from the system: a login service (mingetty) on each tty, syslogd,
14847 the libc name service cache daemon (nscd), the udev device manager, and
14850 This is the default value of the @code{services} field of
14851 @code{operating-system} declarations. Usually, when customizing a
14852 system, you will want to append services to @code{%base-services}, like
14856 (append (list (service avahi-service-type)
14857 (service openssh-service-type))
14862 @defvr {Scheme Variable} special-files-service-type
14863 This is the service that sets up ``special files'' such as
14864 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
14866 The value associated with @code{special-files-service-type} services
14867 must be a list of tuples where the first element is the ``special file''
14868 and the second element is its target. By default it is:
14870 @cindex @file{/bin/sh}
14871 @cindex @file{sh}, in @file{/bin}
14873 `(("/bin/sh" ,(file-append bash "/bin/sh")))
14876 @cindex @file{/usr/bin/env}
14877 @cindex @file{env}, in @file{/usr/bin}
14878 If you want to add, say, @code{/usr/bin/env} to your system, you can
14882 `(("/bin/sh" ,(file-append bash "/bin/sh"))
14883 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
14886 Since this is part of @code{%base-services}, you can use
14887 @code{modify-services} to customize the set of special files
14888 (@pxref{Service Reference, @code{modify-services}}). But the simple way
14889 to add a special file is @i{via} the @code{extra-special-file} procedure
14893 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
14894 Use @var{target} as the ``special file'' @var{file}.
14896 For example, adding the following lines to the @code{services} field of
14897 your operating system declaration leads to a @file{/usr/bin/env}
14901 (extra-special-file "/usr/bin/env"
14902 (file-append coreutils "/bin/env"))
14906 @deffn {Scheme Procedure} host-name-service @var{name}
14907 Return a service that sets the host name to @var{name}.
14910 @defvr {Scheme Variable} console-font-service-type
14911 Install the given fonts on the specified ttys (fonts are per
14912 virtual console on the kernel Linux). The value of this service is a list of
14913 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
14914 package or any valid argument to @command{setfont}, as in this example:
14917 `(("tty1" . "LatGrkCyr-8x16")
14918 ("tty2" . ,(file-append
14920 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
14921 ("tty3" . ,(file-append
14923 "/share/consolefonts/ter-132n"))) ; for HDPI
14927 @deffn {Scheme Procedure} login-service @var{config}
14928 Return a service to run login according to @var{config}, a
14929 @code{<login-configuration>} object, which specifies the message of the day,
14930 among other things.
14933 @deftp {Data Type} login-configuration
14934 This is the data type representing the configuration of login.
14939 @cindex message of the day
14940 A file-like object containing the ``message of the day''.
14942 @item @code{allow-empty-passwords?} (default: @code{#t})
14943 Allow empty passwords by default so that first-time users can log in when
14944 the 'root' account has just been created.
14949 @deffn {Scheme Procedure} mingetty-service @var{config}
14950 Return a service to run mingetty according to @var{config}, a
14951 @code{<mingetty-configuration>} object, which specifies the tty to run, among
14955 @deftp {Data Type} mingetty-configuration
14956 This is the data type representing the configuration of Mingetty, which
14957 provides the default implementation of virtual console log-in.
14962 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
14964 @item @code{auto-login} (default: @code{#f})
14965 When true, this field must be a string denoting the user name under
14966 which the system automatically logs in. When it is @code{#f}, a
14967 user name and password must be entered to log in.
14969 @item @code{login-program} (default: @code{#f})
14970 This must be either @code{#f}, in which case the default log-in program
14971 is used (@command{login} from the Shadow tool suite), or a gexp denoting
14972 the name of the log-in program.
14974 @item @code{login-pause?} (default: @code{#f})
14975 When set to @code{#t} in conjunction with @var{auto-login}, the user
14976 will have to press a key before the log-in shell is launched.
14978 @item @code{clear-on-logout?} (default: @code{#t})
14979 When set to @code{#t}, the screen will be cleared after logout.
14981 @item @code{mingetty} (default: @var{mingetty})
14982 The Mingetty package to use.
14987 @deffn {Scheme Procedure} agetty-service @var{config}
14988 Return a service to run agetty according to @var{config}, an
14989 @code{<agetty-configuration>} object, which specifies the tty to run,
14990 among other things.
14993 @deftp {Data Type} agetty-configuration
14994 This is the data type representing the configuration of agetty, which
14995 implements virtual and serial console log-in. See the @code{agetty(8)}
14996 man page for more information.
15001 The name of the console this agetty runs on, as a string---e.g.,
15002 @code{"ttyS0"}. This argument is optional, it will default to
15003 a reasonable default serial port used by the kernel Linux.
15005 For this, if there is a value for an option @code{agetty.tty} in the kernel
15006 command line, agetty will extract the device name of the serial port
15007 from it and use that.
15009 If not and if there is a value for an option @code{console} with a tty in
15010 the Linux command line, agetty will extract the device name of the
15011 serial port from it and use that.
15013 In both cases, agetty will leave the other serial device settings
15014 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
15017 @item @code{baud-rate} (default: @code{#f})
15018 A string containing a comma-separated list of one or more baud rates, in
15021 @item @code{term} (default: @code{#f})
15022 A string containing the value used for the @env{TERM} environment
15025 @item @code{eight-bits?} (default: @code{#f})
15026 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
15029 @item @code{auto-login} (default: @code{#f})
15030 When passed a login name, as a string, the specified user will be logged
15031 in automatically without prompting for their login name or password.
15033 @item @code{no-reset?} (default: @code{#f})
15034 When @code{#t}, don't reset terminal cflags (control modes).
15036 @item @code{host} (default: @code{#f})
15037 This accepts a string containing the ``login_host'', which will be written
15038 into the @file{/var/run/utmpx} file.
15040 @item @code{remote?} (default: @code{#f})
15041 When set to @code{#t} in conjunction with @var{host}, this will add an
15042 @code{-r} fakehost option to the command line of the login program
15043 specified in @var{login-program}.
15045 @item @code{flow-control?} (default: @code{#f})
15046 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
15048 @item @code{no-issue?} (default: @code{#f})
15049 When set to @code{#t}, the contents of the @file{/etc/issue} file will
15050 not be displayed before presenting the login prompt.
15052 @item @code{init-string} (default: @code{#f})
15053 This accepts a string that will be sent to the tty or modem before
15054 sending anything else. It can be used to initialize a modem.
15056 @item @code{no-clear?} (default: @code{#f})
15057 When set to @code{#t}, agetty will not clear the screen before showing
15060 @item @code{login-program} (default: (file-append shadow "/bin/login"))
15061 This must be either a gexp denoting the name of a log-in program, or
15062 unset, in which case the default value is the @command{login} from the
15065 @item @code{local-line} (default: @code{#f})
15066 Control the CLOCAL line flag. This accepts one of three symbols as
15067 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
15068 the default value chosen by agetty is @code{'auto}.
15070 @item @code{extract-baud?} (default: @code{#f})
15071 When set to @code{#t}, instruct agetty to try to extract the baud rate
15072 from the status messages produced by certain types of modems.
15074 @item @code{skip-login?} (default: @code{#f})
15075 When set to @code{#t}, do not prompt the user for a login name. This
15076 can be used with @var{login-program} field to use non-standard login
15079 @item @code{no-newline?} (default: @code{#f})
15080 When set to @code{#t}, do not print a newline before printing the
15081 @file{/etc/issue} file.
15083 @c Is this dangerous only when used with login-program, or always?
15084 @item @code{login-options} (default: @code{#f})
15085 This option accepts a string containing options that are passed to the
15086 login program. When used with the @var{login-program}, be aware that a
15087 malicious user could try to enter a login name containing embedded
15088 options that could be parsed by the login program.
15090 @item @code{login-pause} (default: @code{#f})
15091 When set to @code{#t}, wait for any key before showing the login prompt.
15092 This can be used in conjunction with @var{auto-login} to save memory by
15093 lazily spawning shells.
15095 @item @code{chroot} (default: @code{#f})
15096 Change root to the specified directory. This option accepts a directory
15099 @item @code{hangup?} (default: @code{#f})
15100 Use the Linux system call @code{vhangup} to do a virtual hangup of the
15101 specified terminal.
15103 @item @code{keep-baud?} (default: @code{#f})
15104 When set to @code{#t}, try to keep the existing baud rate. The baud
15105 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
15108 @item @code{timeout} (default: @code{#f})
15109 When set to an integer value, terminate if no user name could be read
15110 within @var{timeout} seconds.
15112 @item @code{detect-case?} (default: @code{#f})
15113 When set to @code{#t}, turn on support for detecting an uppercase-only
15114 terminal. This setting will detect a login name containing only
15115 uppercase letters as indicating an uppercase-only terminal and turn on
15116 some upper-to-lower case conversions. Note that this will not support
15117 Unicode characters.
15119 @item @code{wait-cr?} (default: @code{#f})
15120 When set to @code{#t}, wait for the user or modem to send a
15121 carriage-return or linefeed character before displaying
15122 @file{/etc/issue} or login prompt. This is typically used with the
15123 @var{init-string} option.
15125 @item @code{no-hints?} (default: @code{#f})
15126 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
15129 @item @code{no-hostname?} (default: @code{#f})
15130 By default, the hostname is printed. When this option is set to
15131 @code{#t}, no hostname will be shown at all.
15133 @item @code{long-hostname?} (default: @code{#f})
15134 By default, the hostname is only printed until the first dot. When this
15135 option is set to @code{#t}, the fully qualified hostname by
15136 @code{gethostname} or @code{getaddrinfo} is shown.
15138 @item @code{erase-characters} (default: @code{#f})
15139 This option accepts a string of additional characters that should be
15140 interpreted as backspace when the user types their login name.
15142 @item @code{kill-characters} (default: @code{#f})
15143 This option accepts a string that should be interpreted to mean ``ignore
15144 all previous characters'' (also called a ``kill'' character) when the user
15145 types their login name.
15147 @item @code{chdir} (default: @code{#f})
15148 This option accepts, as a string, a directory path that will be changed
15151 @item @code{delay} (default: @code{#f})
15152 This options accepts, as an integer, the number of seconds to sleep
15153 before opening the tty and displaying the login prompt.
15155 @item @code{nice} (default: @code{#f})
15156 This option accepts, as an integer, the nice value with which to run the
15157 @command{login} program.
15159 @item @code{extra-options} (default: @code{'()})
15160 This option provides an ``escape hatch'' for the user to provide arbitrary
15161 command-line arguments to @command{agetty} as a list of strings.
15166 @deffn {Scheme Procedure} kmscon-service-type @var{config}
15167 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
15168 according to @var{config}, a @code{<kmscon-configuration>} object, which
15169 specifies the tty to run, among other things.
15172 @deftp {Data Type} kmscon-configuration
15173 This is the data type representing the configuration of Kmscon, which
15174 implements virtual console log-in.
15178 @item @code{virtual-terminal}
15179 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
15181 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
15182 A gexp denoting the name of the log-in program. The default log-in program is
15183 @command{login} from the Shadow tool suite.
15185 @item @code{login-arguments} (default: @code{'("-p")})
15186 A list of arguments to pass to @command{login}.
15188 @item @code{auto-login} (default: @code{#f})
15189 When passed a login name, as a string, the specified user will be logged
15190 in automatically without prompting for their login name or password.
15192 @item @code{hardware-acceleration?} (default: #f)
15193 Whether to use hardware acceleration.
15195 @item @code{font-engine} (default: @code{"pango"})
15196 Font engine used in Kmscon.
15198 @item @code{font-size} (default: @code{12})
15199 Font size used in Kmscon.
15201 @item @code{kmscon} (default: @var{kmscon})
15202 The Kmscon package to use.
15207 @cindex name service cache daemon
15209 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
15210 [#:name-services '()]
15211 Return a service that runs the libc name service cache daemon (nscd) with the
15212 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
15213 Service Switch}, for an example.
15215 For convenience, the Shepherd service for nscd provides the following actions:
15219 @cindex cache invalidation, nscd
15220 @cindex nscd, cache invalidation
15221 This invalidate the given cache. For instance, running:
15224 herd invalidate nscd hosts
15228 invalidates the host name lookup cache of nscd.
15231 Running @command{herd statistics nscd} displays information about nscd usage
15237 @defvr {Scheme Variable} %nscd-default-configuration
15238 This is the default @code{<nscd-configuration>} value (see below) used
15239 by @code{nscd-service}. It uses the caches defined by
15240 @code{%nscd-default-caches}; see below.
15243 @deftp {Data Type} nscd-configuration
15244 This is the data type representing the name service cache daemon (nscd)
15249 @item @code{name-services} (default: @code{'()})
15250 List of packages denoting @dfn{name services} that must be visible to
15251 the nscd---e.g., @code{(list @var{nss-mdns})}.
15253 @item @code{glibc} (default: @var{glibc})
15254 Package object denoting the GNU C Library providing the @command{nscd}
15257 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
15258 Name of the nscd log file. This is where debugging output goes when
15259 @code{debug-level} is strictly positive.
15261 @item @code{debug-level} (default: @code{0})
15262 Integer denoting the debugging levels. Higher numbers mean that more
15263 debugging output is logged.
15265 @item @code{caches} (default: @code{%nscd-default-caches})
15266 List of @code{<nscd-cache>} objects denoting things to be cached; see
15272 @deftp {Data Type} nscd-cache
15273 Data type representing a cache database of nscd and its parameters.
15277 @item @code{database}
15278 This is a symbol representing the name of the database to be cached.
15279 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
15280 @code{services}, which designate the corresponding NSS database
15281 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
15283 @item @code{positive-time-to-live}
15284 @itemx @code{negative-time-to-live} (default: @code{20})
15285 A number representing the number of seconds during which a positive or
15286 negative lookup result remains in cache.
15288 @item @code{check-files?} (default: @code{#t})
15289 Whether to check for updates of the files corresponding to
15292 For instance, when @var{database} is @code{hosts}, setting this flag
15293 instructs nscd to check for updates in @file{/etc/hosts} and to take
15296 @item @code{persistent?} (default: @code{#t})
15297 Whether the cache should be stored persistently on disk.
15299 @item @code{shared?} (default: @code{#t})
15300 Whether the cache should be shared among users.
15302 @item @code{max-database-size} (default: 32@tie{}MiB)
15303 Maximum size in bytes of the database cache.
15305 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
15306 @c settings, so leave them out.
15311 @defvr {Scheme Variable} %nscd-default-caches
15312 List of @code{<nscd-cache>} objects used by default by
15313 @code{nscd-configuration} (see above).
15315 It enables persistent and aggressive caching of service and host name
15316 lookups. The latter provides better host name lookup performance,
15317 resilience in the face of unreliable name servers, and also better
15318 privacy---often the result of host name lookups is in local cache, so
15319 external name servers do not even need to be queried.
15322 @anchor{syslog-configuration-type}
15325 @deftp {Data Type} syslog-configuration
15326 This data type represents the configuration of the syslog daemon.
15329 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
15330 The syslog daemon to use.
15332 @item @code{config-file} (default: @code{%default-syslog.conf})
15333 The syslog configuration file to use.
15338 @anchor{syslog-service}
15340 @deffn {Scheme Procedure} syslog-service @var{config}
15341 Return a service that runs a syslog daemon according to @var{config}.
15343 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
15344 information on the configuration file syntax.
15347 @defvr {Scheme Variable} guix-service-type
15348 This is the type of the service that runs the build daemon,
15349 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
15350 @code{guix-configuration} record as described below.
15353 @anchor{guix-configuration-type}
15354 @deftp {Data Type} guix-configuration
15355 This data type represents the configuration of the Guix build daemon.
15356 @xref{Invoking guix-daemon}, for more information.
15359 @item @code{guix} (default: @var{guix})
15360 The Guix package to use.
15362 @item @code{build-group} (default: @code{"guixbuild"})
15363 Name of the group for build user accounts.
15365 @item @code{build-accounts} (default: @code{10})
15366 Number of build user accounts to create.
15368 @item @code{authorize-key?} (default: @code{#t})
15369 @cindex substitutes, authorization thereof
15370 Whether to authorize the substitute keys listed in
15371 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
15372 (@pxref{Substitutes}).
15374 When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
15375 changed by invoking @command{guix archive --authorize}. You must
15376 instead adjust @code{guix-configuration} as you wish and reconfigure the
15377 system. This ensures that your operating system configuration file is
15381 When booting or reconfiguring to a system where @code{authorize-key?}
15382 is true, the existing @file{/etc/guix/acl} file is backed up as
15383 @file{/etc/guix/acl.bak} if it was determined to be a manually modified
15384 file. This is to facilitate migration from earlier versions, which
15385 allowed for in-place modifications to @file{/etc/guix/acl}.
15388 @vindex %default-authorized-guix-keys
15389 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
15390 The list of authorized key files for archive imports, as a list of
15391 string-valued gexps (@pxref{Invoking guix archive}). By default, it
15392 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
15393 See @code{substitute-urls} below for an example on how to change it.
15395 @item @code{use-substitutes?} (default: @code{#t})
15396 Whether to use substitutes.
15398 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
15399 The list of URLs where to look for substitutes by default.
15401 Suppose you would like to fetch substitutes from @code{guix.example.org}
15402 in addition to @code{@value{SUBSTITUTE-SERVER}}. You will need to do
15403 two things: (1) add @code{guix.example.org} to @code{substitute-urls},
15404 and (2) authorize its signing key, having done appropriate checks
15405 (@pxref{Substitute Server Authorization}). The configuration below does
15409 (guix-configuration
15411 (append (list "https://guix.example.org")
15412 %default-substitute-urls))
15414 (append (list (local-file "./guix.example.org-key.pub"))
15415 %default-authorized-guix-keys)))
15418 This example assumes that the file @file{./guix.example.org-key.pub}
15419 contains the public key that @code{guix.example.org} uses to sign
15422 @item @code{max-silent-time} (default: @code{0})
15423 @itemx @code{timeout} (default: @code{0})
15424 The number of seconds of silence and the number of seconds of activity,
15425 respectively, after which a build process times out. A value of zero
15426 disables the timeout.
15428 @item @code{log-compression} (default: @code{'bzip2})
15429 The type of compression used for build logs---one of @code{gzip},
15430 @code{bzip2}, or @code{none}.
15432 @item @code{discover?} (default: @code{#f})
15433 Whether to discover substitute servers on the local network using mDNS
15436 @item @code{extra-options} (default: @code{'()})
15437 List of extra command-line options for @command{guix-daemon}.
15439 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
15440 File where @command{guix-daemon}'s standard output and standard error
15443 @cindex HTTP proxy, for @code{guix-daemon}
15444 @cindex proxy, for @code{guix-daemon} HTTP access
15445 @item @code{http-proxy} (default: @code{#f})
15446 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
15447 derivations and substitutes.
15449 It is also possible to change the daemon's proxy at run time through the
15450 @code{set-http-proxy} action, which restarts it:
15453 herd set-http-proxy guix-daemon http://localhost:8118
15456 To clear the proxy settings, run:
15459 herd set-http-proxy guix-daemon
15462 @item @code{tmpdir} (default: @code{#f})
15463 A directory path where the @command{guix-daemon} will perform builds.
15468 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
15469 Run @var{udev}, which populates the @file{/dev} directory dynamically.
15470 udev rules can be provided as a list of files through the @var{rules}
15471 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
15472 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
15473 creation of such rule files.
15475 The @command{herd rules udev} command, as root, returns the name of the
15476 directory containing all the active udev rules.
15479 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
15480 Return a udev-rule file named @var{file-name} containing the rules
15481 defined by the @var{contents} literal.
15483 In the following example, a rule for a USB device is defined to be
15484 stored in the file @file{90-usb-thing.rules}. The rule runs a script
15485 upon detecting a USB device with a given product identifier.
15488 (define %example-udev-rule
15490 "90-usb-thing.rules"
15491 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
15492 "ATTR@{product@}==\"Example\", "
15493 "RUN+=\"/path/to/script\"")))
15497 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
15498 [#:groups @var{groups}]
15499 Return a service that extends @code{udev-service-type } with @var{rules}
15500 and @code{account-service-type} with @var{groups} as system groups.
15501 This works by creating a singleton service type
15502 @code{@var{name}-udev-rules}, of which the returned service is an
15505 Here we show how it can be used to extend @code{udev-service-type} with the
15506 previously defined rule @code{%example-udev-rule}.
15512 (cons (udev-rules-service 'usb-thing %example-udev-rule)
15513 %desktop-services)))
15517 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
15518 Return a udev file named @var{file-name} containing the rules defined
15519 within @var{file}, a file-like object.
15521 The following example showcases how we can use an existing rule file.
15524 (use-modules (guix download) ;for url-fetch
15525 (guix packages) ;for origin
15528 (define %android-udev-rules
15530 "51-android-udev.rules"
15531 (let ((version "20170910"))
15534 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
15535 "android-udev-rules/" version "/51-android.rules"))
15537 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
15541 Additionally, Guix package definitions can be included in @var{rules} in
15542 order to extend the udev rules with the definitions found under their
15543 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
15544 @var{file->udev-rule} example, we could have used the
15545 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
15546 packages android)} module.
15548 The following example shows how to use the @var{android-udev-rules}
15549 package so that the Android tool @command{adb} can detect devices
15550 without root privileges. It also details how to create the
15551 @code{adbusers} group, which is required for the proper functioning of
15552 the rules defined within the @code{android-udev-rules} package. To
15553 create such a group, we must define it both as part of the
15554 @code{supplementary-groups} of our @code{user-account} declaration, as
15555 well as in the @var{groups} of the @code{udev-rules-service} procedure.
15558 (use-modules (gnu packages android) ;for android-udev-rules
15559 (gnu system shadow) ;for user-group
15564 (users (cons (user-account
15566 (supplementary-groups
15567 '("adbusers" ;for adb
15568 "wheel" "netdev" "audio" "video")))))
15571 (cons (udev-rules-service 'android android-udev-rules
15572 #:groups '("adbusers"))
15573 %desktop-services)))
15576 @defvr {Scheme Variable} urandom-seed-service-type
15577 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
15578 when rebooting. It also tries to seed @file{/dev/urandom} from
15579 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
15583 @defvr {Scheme Variable} %random-seed-file
15584 This is the name of the file where some random bytes are saved by
15585 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
15586 It defaults to @file{/var/lib/random-seed}.
15591 @defvr {Scheme Variable} gpm-service-type
15592 This is the type of the service that runs GPM, the @dfn{general-purpose
15593 mouse daemon}, which provides mouse support to the Linux console. GPM
15594 allows users to use the mouse in the console, notably to select, copy,
15597 The value for services of this type must be a @code{gpm-configuration}
15598 (see below). This service is not part of @code{%base-services}.
15601 @deftp {Data Type} gpm-configuration
15602 Data type representing the configuration of GPM.
15605 @item @code{options} (default: @code{%default-gpm-options})
15606 Command-line options passed to @command{gpm}. The default set of
15607 options instruct @command{gpm} to listen to mouse events on
15608 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
15611 @item @code{gpm} (default: @code{gpm})
15612 The GPM package to use.
15617 @anchor{guix-publish-service-type}
15618 @deffn {Scheme Variable} guix-publish-service-type
15619 This is the service type for @command{guix publish} (@pxref{Invoking
15620 guix publish}). Its value must be a @code{guix-publish-configuration}
15621 object, as described below.
15623 This assumes that @file{/etc/guix} already contains a signing key pair as
15624 created by @command{guix archive --generate-key} (@pxref{Invoking guix
15625 archive}). If that is not the case, the service will fail to start.
15628 @deftp {Data Type} guix-publish-configuration
15629 Data type representing the configuration of the @code{guix publish}
15633 @item @code{guix} (default: @code{guix})
15634 The Guix package to use.
15636 @item @code{port} (default: @code{80})
15637 The TCP port to listen for connections.
15639 @item @code{host} (default: @code{"localhost"})
15640 The host (and thus, network interface) to listen to. Use
15641 @code{"0.0.0.0"} to listen on all the network interfaces.
15643 @item @code{advertise?} (default: @code{#f})
15644 When true, advertise the service on the local network @i{via} the DNS-SD
15645 protocol, using Avahi.
15647 This allows neighboring Guix devices with discovery on (see
15648 @code{guix-configuration} above) to discover this @command{guix publish}
15649 instance and to automatically download substitutes from it.
15651 @item @code{compression} (default: @code{'(("gzip" 3) ("zstd" 3))})
15652 This is a list of compression method/level tuple used when compressing
15653 substitutes. For example, to compress all substitutes with @emph{both} lzip
15654 at level 7 and gzip at level 9, write:
15657 '(("lzip" 7) ("gzip" 9))
15660 Level 9 achieves the best compression ratio at the expense of increased CPU
15661 usage, whereas level 1 achieves fast compression. @xref{Invoking guix
15662 publish}, for more information on the available compression methods and
15663 the tradeoffs involved.
15665 An empty list disables compression altogether.
15667 @item @code{nar-path} (default: @code{"nar"})
15668 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
15669 publish, @option{--nar-path}}, for details.
15671 @item @code{cache} (default: @code{#f})
15672 When it is @code{#f}, disable caching and instead generate archives on
15673 demand. Otherwise, this should be the name of a directory---e.g.,
15674 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
15675 archives and meta-data ready to be sent. @xref{Invoking guix publish,
15676 @option{--cache}}, for more information on the tradeoffs involved.
15678 @item @code{workers} (default: @code{#f})
15679 When it is an integer, this is the number of worker threads used for
15680 caching; when @code{#f}, the number of processors is used.
15681 @xref{Invoking guix publish, @option{--workers}}, for more information.
15683 @item @code{cache-bypass-threshold} (default: 10 MiB)
15684 When @code{cache} is true, this is the maximum size in bytes of a store
15685 item for which @command{guix publish} may bypass its cache in case of a
15686 cache miss. @xref{Invoking guix publish,
15687 @option{--cache-bypass-threshold}}, for more information.
15689 @item @code{ttl} (default: @code{#f})
15690 When it is an integer, this denotes the @dfn{time-to-live} in seconds
15691 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
15692 for more information.
15696 @anchor{rngd-service}
15697 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
15698 [#:device "/dev/hwrng"]
15699 Return a service that runs the @command{rngd} program from @var{rng-tools}
15700 to add @var{device} to the kernel's entropy pool. The service will fail if
15701 @var{device} does not exist.
15704 @anchor{pam-limits-service}
15705 @cindex session limits
15711 @cindex open file descriptors
15712 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
15714 Return a service that installs a configuration file for the
15715 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
15716 @code{pam_limits} module}. The procedure optionally takes a list of
15717 @code{pam-limits-entry} values, which can be used to specify
15718 @code{ulimit} limits and @code{nice} priority limits to user sessions.
15720 The following limits definition sets two hard and soft limits for all
15721 login sessions of users in the @code{realtime} group:
15724 (pam-limits-service
15726 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
15727 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
15730 The first entry increases the maximum realtime priority for
15731 non-privileged processes; the second entry lifts any restriction of the
15732 maximum address space that can be locked in memory. These settings are
15733 commonly used for real-time audio systems.
15735 Another useful example is raising the maximum number of open file
15736 descriptors that can be used:
15739 (pam-limits-service
15741 (pam-limits-entry "*" 'both 'nofile 100000)))
15744 In the above example, the asterisk means the limit should apply to any
15745 user. It is important to ensure the chosen value doesn't exceed the
15746 maximum system value visible in the @file{/proc/sys/fs/file-max} file,
15747 else the users would be prevented from login in. For more information
15748 about the Pluggable Authentication Module (PAM) limits, refer to the
15749 @samp{pam_limits} man page from the @code{linux-pam} package.
15752 @node Scheduled Job Execution
15753 @subsection Scheduled Job Execution
15757 @cindex scheduling jobs
15758 The @code{(gnu services mcron)} module provides an interface to
15759 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
15760 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
15761 Unix @command{cron} daemon; the main difference is that it is
15762 implemented in Guile Scheme, which provides a lot of flexibility when
15763 specifying the scheduling of jobs and their actions.
15765 The example below defines an operating system that runs the
15766 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
15767 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
15768 well as the @command{mkid} command on behalf of an unprivileged user
15769 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
15770 gexps to introduce job definitions that are passed to mcron
15771 (@pxref{G-Expressions}).
15774 (use-modules (guix) (gnu) (gnu services mcron))
15775 (use-package-modules base idutils)
15777 (define updatedb-job
15778 ;; Run 'updatedb' at 3AM every day. Here we write the
15779 ;; job's action as a Scheme procedure.
15780 #~(job '(next-hour '(3))
15782 (execl (string-append #$findutils "/bin/updatedb")
15784 "--prunepaths=/tmp /var/tmp /gnu/store"))))
15786 (define garbage-collector-job
15787 ;; Collect garbage 5 minutes after midnight every day.
15788 ;; The job's action is a shell command.
15789 #~(job "5 0 * * *" ;Vixie cron syntax
15792 (define idutils-job
15793 ;; Update the index database as user "charlie" at 12:15PM
15794 ;; and 19:15PM. This runs from the user's home directory.
15795 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
15796 (string-append #$idutils "/bin/mkid src")
15802 ;; %BASE-SERVICES already includes an instance of
15803 ;; 'mcron-service-type', which we extend with additional
15804 ;; jobs using 'simple-service'.
15805 (services (cons (simple-service 'my-cron-jobs
15807 (list garbage-collector-job
15813 For more complex jobs defined in Scheme where you need control over the top
15814 level, for instance to introduce a @code{use-modules} form, you can move your
15815 code to a separate program using the @code{program-file} procedure of the
15816 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
15820 (define %battery-alert-job
15821 ;; Beep when the battery percentage falls below %MIN-LEVEL.
15823 '(next-minute (range 0 60 1))
15825 "battery-alert.scm"
15826 (with-imported-modules (source-module-closure
15827 '((guix build utils)))
15829 (use-modules (guix build utils)
15832 (ice-9 textual-ports)
15835 (define %min-level 20)
15837 (setenv "LC_ALL" "C") ;ensure English output
15838 (and-let* ((input-pipe (open-pipe*
15840 #$(file-append acpi "/bin/acpi")))
15841 (output (get-string-all input-pipe))
15842 (m (string-match "Discharging, ([0-9]+)%" output))
15843 (level (string->number (match:substring m 1)))
15844 ((< level %min-level)))
15845 (format #t "warning: Battery level is low (~a%)~%" level)
15846 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
15849 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
15850 for more information on mcron job specifications. Below is the
15851 reference of the mcron service.
15853 On a running system, you can use the @code{schedule} action of the service to
15854 visualize the mcron jobs that will be executed next:
15857 # herd schedule mcron
15861 The example above lists the next five tasks that will be executed, but you can
15862 also specify the number of tasks to display:
15865 # herd schedule mcron 10
15868 @defvr {Scheme Variable} mcron-service-type
15869 This is the type of the @code{mcron} service, whose value is an
15870 @code{mcron-configuration} object.
15872 This service type can be the target of a service extension that provides
15873 it additional job specifications (@pxref{Service Composition}). In
15874 other words, it is possible to define services that provide additional
15878 @deftp {Data Type} mcron-configuration
15879 Data type representing the configuration of mcron.
15882 @item @code{mcron} (default: @var{mcron})
15883 The mcron package to use.
15886 This is a list of gexps (@pxref{G-Expressions}), where each gexp
15887 corresponds to an mcron job specification (@pxref{Syntax, mcron job
15888 specifications,, mcron, GNU@tie{}mcron}).
15894 @subsection Log Rotation
15897 @cindex log rotation
15899 Log files such as those found in @file{/var/log} tend to grow endlessly,
15900 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
15901 their contents in separate files, possibly compressed. The @code{(gnu
15902 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
15903 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
15905 This service is part of @code{%base-services}, and thus enabled by
15906 default, with the default settings, for commonly encountered log files.
15907 The example below shows how to extend it with an additional
15908 @dfn{rotation}, should you need to do that (usually, services that
15909 produce log files already take care of that):
15912 (use-modules (guix) (gnu))
15913 (use-service-modules admin)
15915 (define my-log-files
15916 ;; Log files that I want to rotate.
15917 '("/var/log/something.log" "/var/log/another.log"))
15921 (services (cons (simple-service 'rotate-my-stuff
15922 rottlog-service-type
15923 (list (log-rotation
15925 (files my-log-files))))
15929 @defvr {Scheme Variable} rottlog-service-type
15930 This is the type of the Rottlog service, whose value is a
15931 @code{rottlog-configuration} object.
15933 Other services can extend this one with new @code{log-rotation} objects
15934 (see below), thereby augmenting the set of files to be rotated.
15936 This service type can define mcron jobs (@pxref{Scheduled Job
15937 Execution}) to run the rottlog service.
15940 @deftp {Data Type} rottlog-configuration
15941 Data type representing the configuration of rottlog.
15944 @item @code{rottlog} (default: @code{rottlog})
15945 The Rottlog package to use.
15947 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
15948 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
15949 rottlog, GNU Rot[t]log Manual}).
15951 @item @code{rotations} (default: @code{%default-rotations})
15952 A list of @code{log-rotation} objects as defined below.
15955 This is a list of gexps where each gexp corresponds to an mcron job
15956 specification (@pxref{Scheduled Job Execution}).
15960 @deftp {Data Type} log-rotation
15961 Data type representing the rotation of a group of log files.
15963 Taking an example from the Rottlog manual (@pxref{Period Related File
15964 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
15970 (files '("/var/log/apache/*"))
15971 (options '("storedir apache-archives"
15977 The list of fields is as follows:
15980 @item @code{frequency} (default: @code{'weekly})
15981 The log rotation frequency, a symbol.
15984 The list of files or file glob patterns to rotate.
15986 @item @code{options} (default: @code{'()})
15987 The list of rottlog options for this rotation (@pxref{Configuration
15988 parameters,,, rottlog, GNU Rot[t]lg Manual}).
15990 @item @code{post-rotate} (default: @code{#f})
15991 Either @code{#f} or a gexp to execute once the rotation has completed.
15995 @defvr {Scheme Variable} %default-rotations
15996 Specifies weekly rotation of @code{%rotated-files} and of
15997 @file{/var/log/guix-daemon.log}.
16000 @defvr {Scheme Variable} %rotated-files
16001 The list of syslog-controlled files to be rotated. By default it is:
16002 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
16003 "/var/log/maillog")}.
16006 @node Networking Services
16007 @subsection Networking Services
16009 The @code{(gnu services networking)} module provides services to configure
16010 the network interface.
16012 @cindex DHCP, networking service
16013 @defvr {Scheme Variable} dhcp-client-service-type
16014 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
16015 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
16016 is the DHCP client package to use, @code{isc-dhcp} by default.
16019 @deffn {Scheme Procedure} dhcpd-service-type
16020 This type defines a service that runs a DHCP daemon. To create a
16021 service of this type, you must supply a @code{<dhcpd-configuration>}.
16025 (service dhcpd-service-type
16026 (dhcpd-configuration
16027 (config-file (local-file "my-dhcpd.conf"))
16028 (interfaces '("enp0s25"))))
16032 @deftp {Data Type} dhcpd-configuration
16034 @item @code{package} (default: @code{isc-dhcp})
16035 The package that provides the DHCP daemon. This package is expected to
16036 provide the daemon at @file{sbin/dhcpd} relative to its output
16037 directory. The default package is the
16038 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
16039 @item @code{config-file} (default: @code{#f})
16040 The configuration file to use. This is required. It will be passed to
16041 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
16042 object (@pxref{G-Expressions, file-like objects}). See @code{man
16043 dhcpd.conf} for details on the configuration file syntax.
16044 @item @code{version} (default: @code{"4"})
16045 The DHCP version to use. The ISC DHCP server supports the values ``4'',
16046 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
16047 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
16049 @item @code{run-directory} (default: @code{"/run/dhcpd"})
16050 The run directory to use. At service activation time, this directory
16051 will be created if it does not exist.
16052 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
16053 The PID file to use. This corresponds to the @code{-pf} option of
16054 @code{dhcpd}. See @code{man dhcpd} for details.
16055 @item @code{interfaces} (default: @code{'()})
16056 The names of the network interfaces on which dhcpd should listen for
16057 broadcasts. If this list is not empty, then its elements (which must be
16058 strings) will be appended to the @code{dhcpd} invocation when starting
16059 the daemon. It may not be necessary to explicitly specify any
16060 interfaces here; see @code{man dhcpd} for details.
16064 @defvr {Scheme Variable} static-networking-service-type
16065 This is the type for statically-configured network interfaces.
16066 @c TODO Document <static-networking> data structures.
16069 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
16070 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
16071 [#:requirement @code{'(udev)}]
16072 Return a service that starts @var{interface} with address @var{ip}. If
16073 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
16074 it must be a string specifying the default network gateway. @var{requirement}
16075 can be used to declare a dependency on another service before configuring the
16078 This procedure can be called several times, one for each network
16079 interface of interest. Behind the scenes what it does is extend
16080 @code{static-networking-service-type} with additional network interfaces
16086 (static-networking-service "eno1" "192.168.1.82"
16087 #:gateway "192.168.1.2"
16088 #:name-servers '("192.168.1.2"))
16095 @cindex network management
16096 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
16097 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
16098 management daemon that aims to simplify wired and wireless networking.
16100 This service adds the @var{wicd} package to the global profile, providing
16101 several commands to interact with the daemon and configure networking:
16102 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
16103 and @command{wicd-curses} user interfaces.
16106 @cindex ModemManager
16108 @defvr {Scheme Variable} modem-manager-service-type
16109 This is the service type for the
16110 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
16111 service. The value for this service type is a
16112 @code{modem-manager-configuration} record.
16114 This service is part of @code{%desktop-services} (@pxref{Desktop
16118 @deftp {Data Type} modem-manager-configuration
16119 Data type representing the configuration of ModemManager.
16122 @item @code{modem-manager} (default: @code{modem-manager})
16123 The ModemManager package to use.
16128 @cindex USB_ModeSwitch
16129 @cindex Modeswitching
16131 @defvr {Scheme Variable} usb-modeswitch-service-type
16132 This is the service type for the
16133 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch}
16134 service. The value for this service type is
16135 a @code{usb-modeswitch-configuration} record.
16137 When plugged in, some USB modems (and other USB devices) initially present
16138 themselves as a read-only storage medium and not as a modem. They need to be
16139 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
16140 installs udev rules to automatically modeswitch these devices when they are
16143 This service is part of @code{%desktop-services} (@pxref{Desktop
16147 @deftp {Data Type} usb-modeswitch-configuration
16148 Data type representing the configuration of USB_ModeSwitch.
16151 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
16152 The USB_ModeSwitch package providing the binaries for modeswitching.
16154 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
16155 The package providing the device data and udev rules file used by
16158 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
16159 Which config file to use for the USB_ModeSwitch dispatcher. By default the
16160 config file shipped with USB_ModeSwitch is used which disables logging to
16161 @file{/var/log} among other default settings. If set to @code{#f}, no config
16167 @cindex NetworkManager
16169 @defvr {Scheme Variable} network-manager-service-type
16170 This is the service type for the
16171 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
16172 service. The value for this service type is a
16173 @code{network-manager-configuration} record.
16175 This service is part of @code{%desktop-services} (@pxref{Desktop
16179 @deftp {Data Type} network-manager-configuration
16180 Data type representing the configuration of NetworkManager.
16183 @item @code{network-manager} (default: @code{network-manager})
16184 The NetworkManager package to use.
16186 @item @code{dns} (default: @code{"default"})
16187 Processing mode for DNS, which affects how NetworkManager uses the
16188 @code{resolv.conf} configuration file.
16192 NetworkManager will update @code{resolv.conf} to reflect the nameservers
16193 provided by currently active connections.
16196 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
16197 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
16198 then update @code{resolv.conf} to point to the local nameserver.
16200 With this setting, you can share your network connection. For example when
16201 you want to share your network connection to another laptop @i{via} an
16202 Ethernet cable, you can open @command{nm-connection-editor} and configure the
16203 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
16204 and reestablish the connection (or reboot).
16206 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
16207 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
16208 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
16209 browser on your host system, or connect to the VM @i{via} SSH
16210 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
16211 host-to-guest connection, run this command once:
16214 nmcli connection add type tun \
16215 connection.interface-name tap0 \
16216 tun.mode tap tun.owner $(id -u) \
16217 ipv4.method shared \
16218 ipv4.addresses 172.28.112.1/24
16221 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
16222 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
16223 @command{qemu-system-...}.
16226 NetworkManager will not modify @code{resolv.conf}.
16229 @item @code{vpn-plugins} (default: @code{'()})
16230 This is the list of available plugins for virtual private networks
16231 (VPNs). An example of this is the @code{network-manager-openvpn}
16232 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
16238 @deffn {Scheme Variable} connman-service-type
16239 This is the service type to run @url{https://01.org/connman,Connman},
16240 a network connection manager.
16242 Its value must be an
16243 @code{connman-configuration} record as in this example:
16246 (service connman-service-type
16247 (connman-configuration
16248 (disable-vpn? #t)))
16251 See below for details about @code{connman-configuration}.
16254 @deftp {Data Type} connman-configuration
16255 Data Type representing the configuration of connman.
16258 @item @code{connman} (default: @var{connman})
16259 The connman package to use.
16261 @item @code{disable-vpn?} (default: @code{#f})
16262 When true, disable connman's vpn plugin.
16266 @cindex WPA Supplicant
16267 @defvr {Scheme Variable} wpa-supplicant-service-type
16268 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
16269 supplicant}, an authentication daemon required to authenticate against
16270 encrypted WiFi or ethernet networks.
16273 @deftp {Data Type} wpa-supplicant-configuration
16274 Data type representing the configuration of WPA Supplicant.
16276 It takes the following parameters:
16279 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
16280 The WPA Supplicant package to use.
16282 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
16283 List of services that should be started before WPA Supplicant starts.
16285 @item @code{dbus?} (default: @code{#t})
16286 Whether to listen for requests on D-Bus.
16288 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
16289 Where to store the PID file.
16291 @item @code{interface} (default: @code{#f})
16292 If this is set, it must specify the name of a network interface that
16293 WPA supplicant will control.
16295 @item @code{config-file} (default: @code{#f})
16296 Optional configuration file to use.
16298 @item @code{extra-options} (default: @code{'()})
16299 List of additional command-line arguments to pass to the daemon.
16303 @cindex hostapd service, for Wi-Fi access points
16304 @cindex Wi-Fi access points, hostapd service
16305 @defvr {Scheme Variable} hostapd-service-type
16306 This is the service type to run the @uref{https://w1.fi/hostapd/,
16307 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
16308 authentication servers. Its associated value must be a
16309 @code{hostapd-configuration} as shown below:
16312 ;; Use wlan1 to run the access point for "My Network".
16313 (service hostapd-service-type
16314 (hostapd-configuration
16315 (interface "wlan1")
16316 (ssid "My Network")
16321 @deftp {Data Type} hostapd-configuration
16322 This data type represents the configuration of the hostapd service, with
16323 the following fields:
16326 @item @code{package} (default: @code{hostapd})
16327 The hostapd package to use.
16329 @item @code{interface} (default: @code{"wlan0"})
16330 The network interface to run the WiFi access point.
16333 The SSID (@dfn{service set identifier}), a string that identifies this
16336 @item @code{broadcast-ssid?} (default: @code{#t})
16337 Whether to broadcast this SSID.
16339 @item @code{channel} (default: @code{1})
16340 The WiFi channel to use.
16342 @item @code{driver} (default: @code{"nl80211"})
16343 The driver interface type. @code{"nl80211"} is used with all Linux
16344 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
16345 RADIUS server that does # not control any wireless/wired driver.
16347 @item @code{extra-settings} (default: @code{""})
16348 Extra settings to append as-is to the hostapd configuration file. See
16349 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
16350 configuration file reference.
16354 @defvr {Scheme Variable} simulated-wifi-service-type
16355 This is the type of a service to simulate WiFi networking, which can be
16356 useful in virtual machines for testing purposes. The service loads the
16358 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
16359 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
16360 network that can be seen on @code{wlan0}, by default.
16362 The service's value is a @code{hostapd-configuration} record.
16366 @defvr {Scheme Variable} iptables-service-type
16367 This is the service type to set up an iptables configuration. iptables is a
16368 packet filtering framework supported by the Linux kernel. This service
16369 supports configuring iptables for both IPv4 and IPv6. A simple example
16370 configuration rejecting all incoming connections except those to the ssh port
16374 (service iptables-service-type
16375 (iptables-configuration
16376 (ipv4-rules (plain-file "iptables.rules" "*filter
16380 -A INPUT -p tcp --dport 22 -j ACCEPT
16381 -A INPUT -j REJECT --reject-with icmp-port-unreachable
16384 (ipv6-rules (plain-file "ip6tables.rules" "*filter
16388 -A INPUT -p tcp --dport 22 -j ACCEPT
16389 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
16395 @deftp {Data Type} iptables-configuration
16396 The data type representing the configuration of iptables.
16399 @item @code{iptables} (default: @code{iptables})
16400 The iptables package that provides @code{iptables-restore} and
16401 @code{ip6tables-restore}.
16402 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
16403 The iptables rules to use. It will be passed to @code{iptables-restore}.
16404 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16406 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
16407 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
16408 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16414 @defvr {Scheme Variable} nftables-service-type
16415 This is the service type to set up a nftables configuration. nftables is a
16416 netfilter project that aims to replace the existing iptables, ip6tables,
16417 arptables and ebtables framework. It provides a new packet filtering
16418 framework, a new user-space utility @command{nft}, and a compatibility layer
16419 for iptables. This service comes with a default ruleset
16420 @code{%default-nftables-ruleset} that rejecting all incomming connections
16421 except those to the ssh port 22. To use it, simply write:
16424 (service nftables-service-type)
16428 @deftp {Data Type} nftables-configuration
16429 The data type representing the configuration of nftables.
16432 @item @code{package} (default: @code{nftables})
16433 The nftables package that provides @command{nft}.
16434 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
16435 The nftables ruleset to use. This may be any ``file-like'' object
16436 (@pxref{G-Expressions, file-like objects}).
16440 @cindex NTP (Network Time Protocol), service
16441 @cindex ntpd, service for the Network Time Protocol daemon
16442 @cindex real time clock
16443 @defvr {Scheme Variable} ntp-service-type
16444 This is the type of the service running the @uref{https://www.ntp.org,
16445 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
16446 system clock synchronized with that of the specified NTP servers.
16448 The value of this service is an @code{ntpd-configuration} object, as described
16452 @deftp {Data Type} ntp-configuration
16453 This is the data type for the NTP service configuration.
16456 @item @code{servers} (default: @code{%ntp-servers})
16457 This is the list of servers (@code{<ntp-server>} records) with which
16458 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
16461 @item @code{allow-large-adjustment?} (default: @code{#t})
16462 This determines whether @command{ntpd} is allowed to make an initial
16463 adjustment of more than 1,000 seconds.
16465 @item @code{ntp} (default: @code{ntp})
16466 The NTP package to use.
16470 @defvr {Scheme Variable} %ntp-servers
16471 List of host names used as the default NTP servers. These are servers of the
16472 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
16475 @deftp {Data Type} ntp-server
16476 The data type representing the configuration of a NTP server.
16479 @item @code{type} (default: @code{'server})
16480 The type of the NTP server, given as a symbol. One of @code{'pool},
16481 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
16483 @item @code{address}
16484 The address of the server, as a string.
16486 @item @code{options}
16487 NTPD options to use with that specific server, given as a list of option names
16488 and/or of option names and values tuples. The following example define a server
16489 to use with the options @option{iburst} and @option{prefer}, as well as
16490 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
16495 (address "some.ntp.server.org")
16496 (options `(iburst (version 3) (maxpoll 16) prefer))))
16502 @deffn {Scheme Procedure} openntpd-service-type
16503 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
16504 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
16505 clock synchronized with that of the given servers.
16509 openntpd-service-type
16510 (openntpd-configuration
16511 (listen-on '("127.0.0.1" "::1"))
16512 (sensor '("udcf0 correction 70000"))
16513 (constraint-from '("www.gnu.org"))
16514 (constraints-from '("https://www.google.com/"))))
16519 @defvr {Scheme Variable} %openntpd-servers
16520 This variable is a list of the server addresses defined in
16521 @code{%ntp-servers}.
16524 @deftp {Data Type} openntpd-configuration
16526 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
16527 The openntpd executable to use.
16528 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
16529 A list of local IP addresses or hostnames the ntpd daemon should listen on.
16530 @item @code{query-from} (default: @code{'()})
16531 A list of local IP address the ntpd daemon should use for outgoing queries.
16532 @item @code{sensor} (default: @code{'()})
16533 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
16534 will listen to each sensor that actually exists and ignore non-existent ones.
16535 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
16537 @item @code{server} (default: @code{'()})
16538 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
16539 @item @code{servers} (default: @code{%openntp-servers})
16540 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
16541 @item @code{constraint-from} (default: @code{'()})
16542 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
16543 This time information is not used for precision but acts as an authenticated
16544 constraint, thereby reducing the impact of unauthenticated NTP
16545 man-in-the-middle attacks.
16546 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
16548 @item @code{constraints-from} (default: @code{'()})
16549 As with constraint from, specify a list of URLs, IP addresses or hostnames of
16550 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
16551 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
16556 @deffn {Scheme variable} inetd-service-type
16557 This service runs the @command{inetd} (@pxref{inetd invocation,,,
16558 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
16559 connections on internet sockets, and lazily starts the specified server
16560 program when a connection is made on one of these sockets.
16562 The value of this service is an @code{inetd-configuration} object. The
16563 following example configures the @command{inetd} daemon to provide the
16564 built-in @command{echo} service, as well as an smtp service which
16565 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
16566 gateway @code{hostname}:
16571 (inetd-configuration
16575 (socket-type 'stream)
16582 (socket-type 'stream)
16586 (program (file-append openssh "/bin/ssh"))
16588 '("ssh" "-qT" "-i" "/path/to/ssh_key"
16589 "-W" "smtp-server:25" "user@@hostname")))))))
16592 See below for more details about @code{inetd-configuration}.
16595 @deftp {Data Type} inetd-configuration
16596 Data type representing the configuration of @command{inetd}.
16599 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
16600 The @command{inetd} executable to use.
16602 @item @code{entries} (default: @code{'()})
16603 A list of @command{inetd} service entries. Each entry should be created
16604 by the @code{inetd-entry} constructor.
16608 @deftp {Data Type} inetd-entry
16609 Data type representing an entry in the @command{inetd} configuration.
16610 Each entry corresponds to a socket where @command{inetd} will listen for
16614 @item @code{node} (default: @code{#f})
16615 Optional string, a comma-separated list of local addresses
16616 @command{inetd} should use when listening for this service.
16617 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
16618 description of all options.
16620 A string, the name must correspond to an entry in @code{/etc/services}.
16621 @item @code{socket-type}
16622 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
16624 @item @code{protocol}
16625 A string, must correspond to an entry in @code{/etc/protocols}.
16626 @item @code{wait?} (default: @code{#t})
16627 Whether @command{inetd} should wait for the server to exit before
16628 listening to new service requests.
16630 A string containing the user (and, optionally, group) name of the user
16631 as whom the server should run. The group name can be specified in a
16632 suffix, separated by a colon or period, i.e.@: @code{"user"},
16633 @code{"user:group"} or @code{"user.group"}.
16634 @item @code{program} (default: @code{"internal"})
16635 The server program which will serve the requests, or @code{"internal"}
16636 if @command{inetd} should use a built-in service.
16637 @item @code{arguments} (default: @code{'()})
16638 A list strings or file-like objects, which are the server program's
16639 arguments, starting with the zeroth argument, i.e.@: the name of the
16640 program itself. For @command{inetd}'s internal services, this entry
16641 must be @code{'()} or @code{'("internal")}.
16644 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
16645 detailed discussion of each configuration field.
16649 @defvr {Scheme Variable} tor-service-type
16650 This is the type for a service that runs the @uref{https://torproject.org,
16651 Tor} anonymous networking daemon. The service is configured using a
16652 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
16653 @code{tor} unprivileged user, which is a member of the @code{tor} group.
16657 @deftp {Data Type} tor-configuration
16659 @item @code{tor} (default: @code{tor})
16660 The package that provides the Tor daemon. This package is expected to provide
16661 the daemon at @file{bin/tor} relative to its output directory. The default
16662 package is the @uref{https://www.torproject.org, Tor Project's}
16665 @item @code{config-file} (default: @code{(plain-file "empty" "")})
16666 The configuration file to use. It will be appended to a default configuration
16667 file, and the final configuration file will be passed to @code{tor} via its
16668 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
16669 file-like objects}). See @code{man tor} for details on the configuration file
16672 @item @code{hidden-services} (default: @code{'()})
16673 The list of @code{<hidden-service>} records to use. For any hidden service
16674 you include in this list, appropriate configuration to enable the hidden
16675 service will be automatically added to the default configuration file. You
16676 may conveniently create @code{<hidden-service>} records using the
16677 @code{tor-hidden-service} procedure described below.
16679 @item @code{socks-socket-type} (default: @code{'tcp})
16680 The default socket type that Tor should use for its SOCKS socket. This must
16681 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
16682 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
16683 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
16684 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
16687 If you want to customize the SOCKS socket in more detail, leave
16688 @code{socks-socket-type} at its default value of @code{'tcp} and use
16689 @code{config-file} to override the default by providing your own
16690 @code{SocksPort} option.
16692 @item @code{control-socket?} (default: @code{#f})
16693 Whether or not to provide a ``control socket'' by which Tor can be
16694 controlled to, for instance, dynamically instantiate tor onion services.
16695 If @code{#t}, Tor will listen for control commands on the UNIX domain socket
16696 @file{/var/run/tor/control-sock}, which will be made writable by members of the
16702 @cindex hidden service
16703 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
16704 Define a new Tor @dfn{hidden service} called @var{name} and implementing
16705 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
16708 '((22 "127.0.0.1:22")
16709 (80 "127.0.0.1:8080"))
16712 In this example, port 22 of the hidden service is mapped to local port 22, and
16713 port 80 is mapped to local port 8080.
16715 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
16716 the @file{hostname} file contains the @code{.onion} host name for the hidden
16719 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
16720 project's documentation} for more information.
16723 The @code{(gnu services rsync)} module provides the following services:
16725 You might want an rsync daemon if you have files that you want available
16726 so anyone (or just yourself) can download existing files or upload new
16729 @deffn {Scheme Variable} rsync-service-type
16730 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
16731 The value for this service type is a
16732 @command{rsync-configuration} record as in this example:
16735 (service rsync-service-type)
16738 See below for details about @code{rsync-configuration}.
16741 @deftp {Data Type} rsync-configuration
16742 Data type representing the configuration for @code{rsync-service}.
16745 @item @code{package} (default: @var{rsync})
16746 @code{rsync} package to use.
16748 @item @code{port-number} (default: @code{873})
16749 TCP port on which @command{rsync} listens for incoming connections. If port
16750 is less than @code{1024} @command{rsync} needs to be started as the
16751 @code{root} user and group.
16753 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
16754 Name of the file where @command{rsync} writes its PID.
16756 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
16757 Name of the file where @command{rsync} writes its lock file.
16759 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
16760 Name of the file where @command{rsync} writes its log file.
16762 @item @code{use-chroot?} (default: @var{#t})
16763 Whether to use chroot for @command{rsync} shared directory.
16765 @item @code{share-path} (default: @file{/srv/rsync})
16766 Location of the @command{rsync} shared directory.
16768 @item @code{share-comment} (default: @code{"Rsync share"})
16769 Comment of the @command{rsync} shared directory.
16771 @item @code{read-only?} (default: @var{#f})
16772 Read-write permissions to shared directory.
16774 @item @code{timeout} (default: @code{300})
16775 I/O timeout in seconds.
16777 @item @code{user} (default: @var{"root"})
16778 Owner of the @code{rsync} process.
16780 @item @code{group} (default: @var{"root"})
16781 Group of the @code{rsync} process.
16783 @item @code{uid} (default: @var{"rsyncd"})
16784 User name or user ID that file transfers to and from that module should take
16785 place as when the daemon was run as @code{root}.
16787 @item @code{gid} (default: @var{"rsyncd"})
16788 Group name or group ID that will be used when accessing the module.
16793 The @code{(gnu services syncthing)} module provides the following services:
16796 You might want a syncthing daemon if you have files between two or more
16797 computers and want to sync them in real time, safely protected from
16800 @deffn {Scheme Variable} syncthing-service-type
16801 This is the service type for the @uref{https://syncthing.net/,
16802 syncthing} daemon, The value for this service type is a
16803 @command{syncthing-configuration} record as in this example:
16806 (service syncthing-service-type
16807 (syncthing-configuration (user "alice")))
16810 See below for details about @code{syncthing-configuration}.
16812 @deftp {Data Type} syncthing-configuration
16813 Data type representing the configuration for @code{syncthing-service-type}.
16816 @item @code{syncthing} (default: @var{syncthing})
16817 @code{syncthing} package to use.
16819 @item @code{arguments} (default: @var{'()})
16820 List of command-line arguments passing to @code{syncthing} binary.
16822 @item @code{logflags} (default: @var{0})
16823 Sum of loging flags, see
16824 @uref{https://docs.syncthing.net/users/syncthing.html#cmdoption-logflags, Syncthing documentation logflags}.
16826 @item @code{user} (default: @var{#f})
16827 The user as which the Syncthing service is to be run.
16828 This assumes that the specified user exists.
16830 @item @code{group} (default: @var{"users"})
16831 The group as which the Syncthing service is to be run.
16832 This assumes that the specified group exists.
16834 @item @code{home} (default: @var{#f})
16835 Common configuration and data directory. The default configuration
16836 directory is @file{$HOME} of the specified Syncthing @code{user}.
16842 Furthermore, @code{(gnu services ssh)} provides the following services.
16846 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
16847 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
16848 [#:allow-empty-passwords? #f] [#:root-login? #f] @
16849 [#:syslog-output? #t] [#:x11-forwarding? #t] @
16850 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
16851 [#:public-key-authentication? #t] [#:initialize? #t]
16852 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
16853 @var{host-key} must designate a file containing the host key, and readable
16856 When @var{daemonic?} is true, @command{lshd} will detach from the
16857 controlling terminal and log its output to syslogd, unless one sets
16858 @var{syslog-output?} to false. Obviously, it also makes lsh-service
16859 depend on existence of syslogd service. When @var{pid-file?} is true,
16860 @command{lshd} writes its PID to the file called @var{pid-file}.
16862 When @var{initialize?} is true, automatically create the seed and host key
16863 upon service activation if they do not exist yet. This may take long and
16864 require interaction.
16866 When @var{initialize?} is false, it is up to the user to initialize the
16867 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
16868 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
16869 basics,,, lsh, LSH Manual}).
16871 When @var{interfaces} is empty, lshd listens for connections on all the
16872 network interfaces; otherwise, @var{interfaces} must be a list of host names
16875 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
16876 passwords, and @var{root-login?} specifies whether to accept log-ins as
16879 The other options should be self-descriptive.
16884 @deffn {Scheme Variable} openssh-service-type
16885 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
16886 shell daemon, @command{sshd}. Its value must be an
16887 @code{openssh-configuration} record as in this example:
16890 (service openssh-service-type
16891 (openssh-configuration
16892 (x11-forwarding? #t)
16893 (permit-root-login 'without-password)
16895 `(("alice" ,(local-file "alice.pub"))
16896 ("bob" ,(local-file "bob.pub"))))))
16899 See below for details about @code{openssh-configuration}.
16901 This service can be extended with extra authorized keys, as in this
16905 (service-extension openssh-service-type
16906 (const `(("charlie"
16907 ,(local-file "charlie.pub")))))
16911 @deftp {Data Type} openssh-configuration
16912 This is the configuration record for OpenSSH's @command{sshd}.
16915 @item @code{openssh} (default @var{openssh})
16916 The Openssh package to use.
16918 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
16919 Name of the file where @command{sshd} writes its PID.
16921 @item @code{port-number} (default: @code{22})
16922 TCP port on which @command{sshd} listens for incoming connections.
16924 @item @code{permit-root-login} (default: @code{#f})
16925 This field determines whether and when to allow logins as root. If
16926 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
16927 If it's the symbol @code{'without-password}, then root logins are
16928 permitted but not with password-based authentication.
16930 @item @code{allow-empty-passwords?} (default: @code{#f})
16931 When true, users with empty passwords may log in. When false, they may
16934 @item @code{password-authentication?} (default: @code{#t})
16935 When true, users may log in with their password. When false, they have
16936 other authentication methods.
16938 @item @code{public-key-authentication?} (default: @code{#t})
16939 When true, users may log in using public key authentication. When
16940 false, users have to use other authentication method.
16942 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
16943 This is used only by protocol version 2.
16945 @item @code{x11-forwarding?} (default: @code{#f})
16946 When true, forwarding of X11 graphical client connections is
16947 enabled---in other words, @command{ssh} options @option{-X} and
16948 @option{-Y} will work.
16950 @item @code{allow-agent-forwarding?} (default: @code{#t})
16951 Whether to allow agent forwarding.
16953 @item @code{allow-tcp-forwarding?} (default: @code{#t})
16954 Whether to allow TCP forwarding.
16956 @item @code{gateway-ports?} (default: @code{#f})
16957 Whether to allow gateway ports.
16959 @item @code{challenge-response-authentication?} (default: @code{#f})
16960 Specifies whether challenge response authentication is allowed (e.g.@: via
16963 @item @code{use-pam?} (default: @code{#t})
16964 Enables the Pluggable Authentication Module interface. If set to
16965 @code{#t}, this will enable PAM authentication using
16966 @code{challenge-response-authentication?} and
16967 @code{password-authentication?}, in addition to PAM account and session
16968 module processing for all authentication types.
16970 Because PAM challenge response authentication usually serves an
16971 equivalent role to password authentication, you should disable either
16972 @code{challenge-response-authentication?} or
16973 @code{password-authentication?}.
16975 @item @code{print-last-log?} (default: @code{#t})
16976 Specifies whether @command{sshd} should print the date and time of the
16977 last user login when a user logs in interactively.
16979 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
16980 Configures external subsystems (e.g.@: file transfer daemon).
16982 This is a list of two-element lists, each of which containing the
16983 subsystem name and a command (with optional arguments) to execute upon
16986 The command @command{internal-sftp} implements an in-process SFTP
16987 server. Alternatively, one can specify the @command{sftp-server} command:
16989 (service openssh-service-type
16990 (openssh-configuration
16992 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
16995 @item @code{accepted-environment} (default: @code{'()})
16996 List of strings describing which environment variables may be exported.
16998 Each string gets on its own line. See the @code{AcceptEnv} option in
16999 @code{man sshd_config}.
17001 This example allows ssh-clients to export the @env{COLORTERM} variable.
17002 It is set by terminal emulators, which support colors. You can use it in
17003 your shell's resource file to enable colors for the prompt and commands
17004 if this variable is set.
17007 (service openssh-service-type
17008 (openssh-configuration
17009 (accepted-environment '("COLORTERM"))))
17012 @item @code{authorized-keys} (default: @code{'()})
17013 @cindex authorized keys, SSH
17014 @cindex SSH authorized keys
17015 This is the list of authorized keys. Each element of the list is a user
17016 name followed by one or more file-like objects that represent SSH public
17020 (openssh-configuration
17022 `(("rekado" ,(local-file "rekado.pub"))
17023 ("chris" ,(local-file "chris.pub"))
17024 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
17028 registers the specified public keys for user accounts @code{rekado},
17029 @code{chris}, and @code{root}.
17031 Additional authorized keys can be specified @i{via}
17032 @code{service-extension}.
17034 Note that this does @emph{not} interfere with the use of
17035 @file{~/.ssh/authorized_keys}.
17037 @item @code{log-level} (default: @code{'info})
17038 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
17039 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
17040 page for @file{sshd_config} for the full list of level names.
17042 @item @code{extra-content} (default: @code{""})
17043 This field can be used to append arbitrary text to the configuration file. It
17044 is especially useful for elaborate configurations that cannot be expressed
17045 otherwise. This configuration, for example, would generally disable root
17046 logins, but permit them from one specific IP address:
17049 (openssh-configuration
17051 Match Address 192.168.0.1
17052 PermitRootLogin yes"))
17058 @deffn {Scheme Procedure} dropbear-service [@var{config}]
17059 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
17060 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
17063 For example, to specify a Dropbear service listening on port 1234, add
17064 this call to the operating system's @code{services} field:
17067 (dropbear-service (dropbear-configuration
17068 (port-number 1234)))
17072 @deftp {Data Type} dropbear-configuration
17073 This data type represents the configuration of a Dropbear SSH daemon.
17076 @item @code{dropbear} (default: @var{dropbear})
17077 The Dropbear package to use.
17079 @item @code{port-number} (default: 22)
17080 The TCP port where the daemon waits for incoming connections.
17082 @item @code{syslog-output?} (default: @code{#t})
17083 Whether to enable syslog output.
17085 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
17086 File name of the daemon's PID file.
17088 @item @code{root-login?} (default: @code{#f})
17089 Whether to allow @code{root} logins.
17091 @item @code{allow-empty-passwords?} (default: @code{#f})
17092 Whether to allow empty passwords.
17094 @item @code{password-authentication?} (default: @code{#t})
17095 Whether to enable password-based authentication.
17100 @deffn {Scheme Variable} autossh-service-type
17101 This is the type for the @uref{https://www.harding.motd.ca/autossh,
17102 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
17103 restarting it as necessary should it die or stop passing traffic.
17104 AutoSSH can be run manually from the command-line by passing arguments
17105 to the binary @command{autossh} from the package @code{autossh}, but it
17106 can also be run as a Guix service. This latter use case is documented
17109 AutoSSH can be used to forward local traffic to a remote machine using
17110 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
17113 For example, to specify a service running autossh as the user
17114 @code{pino} and forwarding all local connections to port @code{8081} to
17115 @code{remote:8081} using an SSH tunnel, add this call to the operating
17116 system's @code{services} field:
17119 (service autossh-service-type
17120 (autossh-configuration
17122 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
17126 @deftp {Data Type} autossh-configuration
17127 This data type represents the configuration of an AutoSSH service.
17131 @item @code{user} (default @code{"autossh"})
17132 The user as which the AutoSSH service is to be run.
17133 This assumes that the specified user exists.
17135 @item @code{poll} (default @code{600})
17136 Specifies the connection poll time in seconds.
17138 @item @code{first-poll} (default @code{#f})
17139 Specifies how many seconds AutoSSH waits before the first connection
17140 test. After this first test, polling is resumed at the pace defined in
17141 @code{poll}. When set to @code{#f}, the first poll is not treated
17142 specially and will also use the connection poll specified in
17145 @item @code{gate-time} (default @code{30})
17146 Specifies how many seconds an SSH connection must be active before it is
17147 considered successful.
17149 @item @code{log-level} (default @code{1})
17150 The log level, corresponding to the levels used by syslog---so @code{0}
17151 is the most silent while @code{7} is the chattiest.
17153 @item @code{max-start} (default @code{#f})
17154 The maximum number of times SSH may be (re)started before AutoSSH exits.
17155 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
17157 @item @code{message} (default @code{""})
17158 The message to append to the echo message sent when testing connections.
17160 @item @code{port} (default @code{"0"})
17161 The ports used for monitoring the connection. When set to @code{"0"},
17162 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
17163 a positive integer, ports @var{n} and @var{n}+1 are used for
17164 monitoring the connection, such that port @var{n} is the base
17165 monitoring port and @code{n+1} is the echo port. When set to
17166 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
17167 integers, the ports @var{n} and @var{m} are used for monitoring the
17168 connection, such that port @var{n} is the base monitoring port and
17169 @var{m} is the echo port.
17171 @item @code{ssh-options} (default @code{'()})
17172 The list of command-line arguments to pass to @command{ssh} when it is
17173 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
17174 may cause undefined behaviour.
17180 @deffn {Scheme Variable} webssh-service-type
17181 This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
17182 program that runs a web SSH client. WebSSH can be run manually from the
17183 command-line by passing arguments to the binary @command{wssh} from the
17184 package @code{webssh}, but it can also be run as a Guix service. This
17185 latter use case is documented here.
17187 For example, to specify a service running WebSSH on loopback interface
17188 on port @code{8888} with reject policy with a list of allowed to
17189 connection hosts, and NGINX as a reverse-proxy to this service listening
17190 for HTTPS connection, add this call to the operating system's
17191 @code{services} field:
17194 (service webssh-service-type
17195 (webssh-configuration (address "127.0.0.1")
17198 (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
17199 "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
17201 (service nginx-service-type
17202 (nginx-configuration
17205 (nginx-server-configuration
17206 (inherit %webssh-configuration-nginx)
17207 (server-name '("webssh.example.com"))
17208 (listen '("443 ssl"))
17209 (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
17210 (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
17212 (cons (nginx-location-configuration
17213 (uri "/.well-known")
17214 (body '("root /var/www;")))
17215 (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
17219 @deftp {Data Type} webssh-configuration
17220 Data type representing the configuration for @code{webssh-service}.
17223 @item @code{package} (default: @var{webssh})
17224 @code{webssh} package to use.
17226 @item @code{user-name} (default: @var{"webssh"})
17227 User name or user ID that file transfers to and from that module should take
17230 @item @code{group-name} (default: @var{"webssh"})
17231 Group name or group ID that will be used when accessing the module.
17233 @item @code{address} (default: @var{#f})
17234 IP address on which @command{webssh} listens for incoming connections.
17236 @item @code{port} (default: @var{8888})
17237 TCP port on which @command{webssh} listens for incoming connections.
17239 @item @code{policy} (default: @var{#f})
17240 Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
17242 @item @code{known-hosts} (default: @var{'()})
17243 List of hosts which allowed for SSH connection from @command{webssh}.
17245 @item @code{log-file} (default: @file{"/var/log/webssh.log"})
17246 Name of the file where @command{webssh} writes its log file.
17248 @item @code{log-level} (default: @var{#f})
17254 @defvr {Scheme Variable} %facebook-host-aliases
17255 This variable contains a string for use in @file{/etc/hosts}
17256 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
17257 line contains a entry that maps a known server name of the Facebook
17258 on-line service---e.g., @code{www.facebook.com}---to the local
17259 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
17261 This variable is typically used in the @code{hosts-file} field of an
17262 @code{operating-system} declaration (@pxref{operating-system Reference,
17263 @file{/etc/hosts}}):
17266 (use-modules (gnu) (guix))
17269 (host-name "mymachine")
17272 ;; Create a /etc/hosts file with aliases for "localhost"
17273 ;; and "mymachine", as well as for Facebook servers.
17274 (plain-file "hosts"
17275 (string-append (local-host-aliases host-name)
17276 %facebook-host-aliases))))
17279 This mechanism can prevent programs running locally, such as Web
17280 browsers, from accessing Facebook.
17283 The @code{(gnu services avahi)} provides the following definition.
17285 @defvr {Scheme Variable} avahi-service-type
17286 This is the service that runs @command{avahi-daemon}, a system-wide
17287 mDNS/DNS-SD responder that allows for service discovery and
17288 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
17289 Its value must be an @code{avahi-configuration} record---see below.
17291 This service extends the name service cache daemon (nscd) so that it can
17292 resolve @code{.local} host names using
17293 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
17294 Service Switch}, for information on host name resolution.
17296 Additionally, add the @var{avahi} package to the system profile so that
17297 commands such as @command{avahi-browse} are directly usable.
17300 @deftp {Data Type} avahi-configuration
17301 Data type representation the configuration for Avahi.
17305 @item @code{host-name} (default: @code{#f})
17306 If different from @code{#f}, use that as the host name to
17307 publish for this machine; otherwise, use the machine's actual host name.
17309 @item @code{publish?} (default: @code{#t})
17310 When true, allow host names and services to be published (broadcast) over the
17313 @item @code{publish-workstation?} (default: @code{#t})
17314 When true, @command{avahi-daemon} publishes the machine's host name and IP
17315 address via mDNS on the local network. To view the host names published on
17316 your local network, you can run:
17319 avahi-browse _workstation._tcp
17322 @item @code{wide-area?} (default: @code{#f})
17323 When true, DNS-SD over unicast DNS is enabled.
17325 @item @code{ipv4?} (default: @code{#t})
17326 @itemx @code{ipv6?} (default: @code{#t})
17327 These fields determine whether to use IPv4/IPv6 sockets.
17329 @item @code{domains-to-browse} (default: @code{'()})
17330 This is a list of domains to browse.
17334 @deffn {Scheme Variable} openvswitch-service-type
17335 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
17336 service, whose value should be an @code{openvswitch-configuration}
17340 @deftp {Data Type} openvswitch-configuration
17341 Data type representing the configuration of Open vSwitch, a multilayer
17342 virtual switch which is designed to enable massive network automation
17343 through programmatic extension.
17346 @item @code{package} (default: @var{openvswitch})
17347 Package object of the Open vSwitch.
17352 @defvr {Scheme Variable} pagekite-service-type
17353 This is the service type for the @uref{https://pagekite.net, PageKite} service,
17354 a tunneling solution for making localhost servers publicly visible, even from
17355 behind restrictive firewalls or NAT without forwarded ports. The value for
17356 this service type is a @code{pagekite-configuration} record.
17358 Here's an example exposing the local HTTP and SSH daemons:
17361 (service pagekite-service-type
17362 (pagekite-configuration
17363 (kites '("http:@@kitename:localhost:80:@@kitesecret"
17364 "raw/22:@@kitename:localhost:22:@@kitesecret"))
17365 (extra-file "/etc/pagekite.rc")))
17369 @deftp {Data Type} pagekite-configuration
17370 Data type representing the configuration of PageKite.
17373 @item @code{package} (default: @var{pagekite})
17374 Package object of PageKite.
17376 @item @code{kitename} (default: @code{#f})
17377 PageKite name for authenticating to the frontend server.
17379 @item @code{kitesecret} (default: @code{#f})
17380 Shared secret for authenticating to the frontend server. You should probably
17381 put this inside @code{extra-file} instead.
17383 @item @code{frontend} (default: @code{#f})
17384 Connect to the named PageKite frontend server instead of the
17385 @uref{https://pagekite.net,,pagekite.net} service.
17387 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
17388 List of service kites to use. Exposes HTTP on port 80 by default. The format
17389 is @code{proto:kitename:host:port:secret}.
17391 @item @code{extra-file} (default: @code{#f})
17392 Extra configuration file to read, which you are expected to create manually.
17393 Use this to add additional options and manage shared secrets out-of-band.
17398 @defvr {Scheme Variable} yggdrasil-service-type
17399 The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
17400 Yggdrasil network}, an early-stage implementation of a fully end-to-end
17401 encrypted IPv6 network.
17404 Yggdrasil provides name-independent routing with cryptographically generated
17405 addresses. Static addressing means you can keep the same address as long as
17406 you want, even if you move to a new location, or generate a new address (by
17407 generating new keys) whenever you want.
17408 @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
17411 Pass it a value of @code{yggdrasil-configuration} to connect it to public
17412 peers and/or local peers.
17414 Here is an example using public peers and a static address. The static
17415 signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
17416 (the default value for @code{config-file}).
17419 ;; part of the operating-system declaration
17420 (service yggdrasil-service-type
17421 (yggdrasil-configuration
17422 (autoconf? #f) ;; use only the public peers
17425 ;; https://github.com/yggdrasil-network/public-peers
17426 '((peers . #("tcp://1.2.3.4:1337"))))
17427 ;; /etc/yggdrasil-private.conf is the default value for config-file
17431 # sample content for /etc/yggdrasil-private.conf
17433 # Your public encryption key. Your peers may ask you for this to put
17434 # into their AllowedEncryptionPublicKeys configuration.
17435 EncryptionPublicKey: 378dc5...
17437 # Your private encryption key. DO NOT share this with anyone!
17438 EncryptionPrivateKey: 0777...
17440 # Your public signing key. You should not ordinarily need to share
17441 # this with anyone.
17442 SigningPublicKey: e1664...
17444 # Your private signing key. DO NOT share this with anyone!
17445 SigningPrivateKey: 0589d...
17450 @deftp {Data Type} yggdrasil-configuration
17451 Data type representing the configuration of Yggdrasil.
17454 @item @code{package} (default: @code{yggdrasil})
17455 Package object of Yggdrasil.
17457 @item @code{json-config} (default: @code{'()})
17458 Contents of @file{/etc/yggdrasil.conf}. Will be merged with
17459 @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
17460 the Guix store, which is readable to all users. @strong{Do not store your
17461 private keys in it}. See the output of @code{yggdrasil -genconf} for a
17462 quick overview of valid keys and their default values.
17464 @item @code{autoconf?} (default: @code{#f})
17465 Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
17466 and peer with IPv6 neighbors.
17468 @item @code{log-level} (default: @code{'info})
17469 How much detail to include in logs. Use @code{'debug} for more detail.
17471 @item @code{log-to} (default: @code{'stdout})
17472 Where to send logs. By default, the service logs standard output to
17473 @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
17474 sends output to the running syslog service.
17476 @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
17477 What HJSON file to load sensitive data from. This is where private keys
17478 should be stored, which are necessary to specify if you don't want a
17479 randomized address after each restart. Use @code{#f} to disable. Options
17480 defined in this file take precedence over @code{json-config}. Use the output
17481 of @code{yggdrasil -genconf} as a starting point. To configure a static
17482 address, delete everything except these options:
17485 @item @code{EncryptionPublicKey}
17486 @item @code{EncryptionPrivateKey}
17487 @item @code{SigningPublicKey}
17488 @item @code{SigningPrivateKey}
17494 @deffn {Scheme Variable} keepalived-service-type
17495 This is the type for the @uref{https://www.keepalived.org/, Keepalived}
17496 routing software, @command{keepalived}. Its value must be an
17497 @code{keepalived-configuration} record as in this example for master
17501 (service keepalived-service-type
17502 (keepalived-configuration
17503 (config-file (local-file "keepalived-master.conf"))))
17506 where @file{keepalived-master.conf}:
17509 vrrp_instance my-group @{
17512 virtual_router_id 100
17514 unicast_peer @{ 10.0.0.2 @}
17515 virtual_ipaddress @{
17521 and for backup machine:
17524 (service keepalived-service-type
17525 (keepalived-configuration
17526 (config-file (local-file "keepalived-backup.conf"))))
17529 where @file{keepalived-backup.conf}:
17532 vrrp_instance my-group @{
17535 virtual_router_id 100
17537 unicast_peer @{ 10.0.0.3 @}
17538 virtual_ipaddress @{
17545 @node Unattended Upgrades
17546 @subsection Unattended Upgrades
17548 @cindex unattended upgrades
17549 @cindex upgrades, unattended
17550 Guix provides a service to perform @emph{unattended upgrades}:
17551 periodically, the system automatically reconfigures itself from the
17552 latest Guix. Guix System has several properties that make unattended
17557 upgrades are transactional (either the upgrade succeeds or it fails, but
17558 you cannot end up with an ``in-between'' system state);
17560 the upgrade log is kept---you can view it with @command{guix system
17561 list-generations}---and you can roll back to any previous generation,
17562 should the upgraded system fail to behave as intended;
17564 channel code is authenticated so you know you can only run genuine code
17565 (@pxref{Channels});
17567 @command{guix system reconfigure} prevents downgrades, which makes it
17568 immune to @dfn{downgrade attacks}.
17571 To set up unattended upgrades, add an instance of
17572 @code{unattended-upgrade-service-type} like the one below to the list of
17573 your operating system services:
17576 (service unattended-upgrade-service-type)
17579 The defaults above set up weekly upgrades: every Sunday at midnight.
17580 You do not need to provide the operating system configuration file: it
17581 uses @file{/run/current-system/configuration.scm}, which ensures it
17582 always uses your latest configuration---@pxref{provenance-service-type},
17583 for more information about this file.
17585 There are several things that can be configured, in particular the
17586 periodicity and services (daemons) to be restarted upon completion.
17587 When the upgrade is successful, the service takes care of deleting
17588 system generations older that some threshold, as per @command{guix
17589 system delete-generations}. See the reference below for details.
17591 To ensure that upgrades are actually happening, you can run
17592 @command{guix system describe}. To investigate upgrade failures, visit
17593 the unattended upgrade log file (see below).
17595 @defvr {Scheme Variable} unattended-upgrade-service-type
17596 This is the service type for unattended upgrades. It sets up an mcron
17597 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
17598 reconfigure} from the latest version of the specified channels.
17600 Its value must be a @code{unattended-upgrade-configuration} record (see
17604 @deftp {Data Type} unattended-upgrade-configuration
17605 This data type represents the configuration of the unattended upgrade
17606 service. The following fields are available:
17609 @item @code{schedule} (default: @code{"30 01 * * 0"})
17610 This is the schedule of upgrades, expressed as a gexp containing an
17611 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
17612 mcron, GNU@tie{}mcron}).
17614 @item @code{channels} (default: @code{#~%default-channels})
17615 This gexp specifies the channels to use for the upgrade
17616 (@pxref{Channels}). By default, the tip of the official @code{guix}
17619 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
17620 This field specifies the operating system configuration file to use.
17621 The default is to reuse the config file of the current configuration.
17623 There are cases, though, where referring to
17624 @file{/run/current-system/configuration.scm} is not enough, for instance
17625 because that file refers to extra files (SSH public keys, extra
17626 configuration files, etc.) @i{via} @code{local-file} and similar
17627 constructs. For those cases, we recommend something along these lines:
17630 (unattended-upgrade-configuration
17631 (operating-system-file
17632 (file-append (local-file "." "config-dir" #:recursive? #t)
17636 The effect here is to import all of the current directory into the
17637 store, and to refer to @file{config.scm} within that directory.
17638 Therefore, uses of @code{local-file} within @file{config.scm} will work
17639 as expected. @xref{G-Expressions}, for information about
17640 @code{local-file} and @code{file-append}.
17642 @item @code{services-to-restart} (default: @code{'(mcron)})
17643 This field specifies the Shepherd services to restart when the upgrade
17646 Those services are restarted right away upon completion, as with
17647 @command{herd restart}, which ensures that the latest version is
17648 running---remember that by default @command{guix system reconfigure}
17649 only restarts services that are not currently running, which is
17650 conservative: it minimizes disruption but leaves outdated services
17653 Use @command{herd status} to find out candidates for restarting.
17654 @xref{Services}, for general information about services. Common
17655 services to restart would include @code{ntpd} and @code{ssh-daemon}.
17657 By default, the @code{mcron} service is restarted. This ensures that
17658 the latest version of the unattended upgrade job will be used next time.
17660 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
17661 This is the expiration time in seconds for system generations. System
17662 generations older that this amount of time are deleted with
17663 @command{guix system delete-generations} when an upgrade completes.
17666 The unattended upgrade service does not run the garbage collector. You
17667 will probably want to set up your own mcron job to run @command{guix gc}
17671 @item @code{maximum-duration} (default: @code{3600})
17672 Maximum duration in seconds for the upgrade; past that time, the upgrade
17675 This is primarily useful to ensure the upgrade does not end up
17676 rebuilding or re-downloading ``the world''.
17678 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
17679 File where unattended upgrades are logged.
17684 @subsection X Window
17687 @cindex X Window System
17688 @cindex login manager
17689 Support for the X Window graphical display system---specifically
17690 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
17691 there is no @code{xorg-service} procedure. Instead, the X server is
17692 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
17695 @cindex GNOME, login manager
17696 GDM of course allows users to log in into window managers and desktop
17697 environments other than GNOME; for those using GNOME, GDM is required for
17698 features such as automatic screen locking.
17700 @cindex window manager
17701 To use X11, you must install at least one @dfn{window manager}---for
17702 example the @code{windowmaker} or @code{openbox} packages---preferably
17703 by adding it to the @code{packages} field of your operating system
17704 definition (@pxref{operating-system Reference, system-wide packages}).
17706 @defvr {Scheme Variable} gdm-service-type
17707 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
17708 Desktop Manager} (GDM), a program that manages graphical display servers and
17709 handles graphical user logins. Its value must be a @code{gdm-configuration}
17712 @cindex session types (X11)
17713 @cindex X11 session types
17714 GDM looks for @dfn{session types} described by the @file{.desktop} files in
17715 @file{/run/current-system/profile/share/xsessions} and allows users to choose
17716 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
17717 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
17718 set of packages automatically makes them available at the log-in screen.
17720 In addition, @file{~/.xsession} files are honored. When available,
17721 @file{~/.xsession} must be an executable that starts a window manager
17722 and/or other X clients.
17725 @deftp {Data Type} gdm-configuration
17727 @item @code{auto-login?} (default: @code{#f})
17728 @itemx @code{default-user} (default: @code{#f})
17729 When @code{auto-login?} is false, GDM presents a log-in screen.
17731 When @code{auto-login?} is true, GDM logs in directly as
17732 @code{default-user}.
17734 @item @code{debug?} (default: @code{#f})
17735 When true, GDM writes debug messages to its log.
17737 @item @code{gnome-shell-assets} (default: ...)
17738 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
17740 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
17741 Configuration of the Xorg graphical server.
17743 @item @code{xsession} (default: @code{(xinitrc)})
17744 Script to run before starting a X session.
17746 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
17747 File name of the @code{dbus-daemon} executable.
17749 @item @code{gdm} (default: @code{gdm})
17750 The GDM package to use.
17754 @defvr {Scheme Variable} slim-service-type
17755 This is the type for the SLiM graphical login manager for X11.
17757 Like GDM, SLiM looks for session types described by @file{.desktop} files and
17758 allows users to choose a session from the log-in screen using @kbd{F1}. It
17759 also honors @file{~/.xsession} files.
17761 Unlike GDM, SLiM does not spawn the user session on a different VT after
17762 logging in, which means that you can only start one graphical session. If you
17763 want to be able to run multiple graphical sessions at the same time you have
17764 to add multiple SLiM services to your system services. The following example
17765 shows how to replace the default GDM service with two SLiM services on tty7
17769 (use-modules (gnu services)
17770 (gnu services desktop)
17771 (gnu services xorg)
17772 (srfi srfi-1)) ;for 'remove'
17776 (services (cons* (service slim-service-type (slim-configuration
17779 (service slim-service-type (slim-configuration
17782 (remove (lambda (service)
17783 (eq? (service-kind service) gdm-service-type))
17784 %desktop-services))))
17789 @deftp {Data Type} slim-configuration
17790 Data type representing the configuration of @code{slim-service-type}.
17793 @item @code{allow-empty-passwords?} (default: @code{#t})
17794 Whether to allow logins with empty passwords.
17796 @item @code{auto-login?} (default: @code{#f})
17797 @itemx @code{default-user} (default: @code{""})
17798 When @code{auto-login?} is false, SLiM presents a log-in screen.
17800 When @code{auto-login?} is true, SLiM logs in directly as
17801 @code{default-user}.
17803 @item @code{theme} (default: @code{%default-slim-theme})
17804 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
17805 The graphical theme to use and its name.
17807 @item @code{auto-login-session} (default: @code{#f})
17808 If true, this must be the name of the executable to start as the default
17809 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
17811 If false, a session described by one of the available @file{.desktop}
17812 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
17816 You must install at least one window manager in the system profile or in
17817 your user profile. Failing to do that, if @code{auto-login-session} is
17818 false, you will be unable to log in.
17821 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17822 Configuration of the Xorg graphical server.
17824 @item @code{display} (default @code{":0"})
17825 The display on which to start the Xorg graphical server.
17827 @item @code{vt} (default @code{"vt7"})
17828 The VT on which to start the Xorg graphical server.
17830 @item @code{xauth} (default: @code{xauth})
17831 The XAuth package to use.
17833 @item @code{shepherd} (default: @code{shepherd})
17834 The Shepherd package used when invoking @command{halt} and
17837 @item @code{sessreg} (default: @code{sessreg})
17838 The sessreg package used in order to register the session.
17840 @item @code{slim} (default: @code{slim})
17841 The SLiM package to use.
17845 @defvr {Scheme Variable} %default-theme
17846 @defvrx {Scheme Variable} %default-theme-name
17847 The default SLiM theme and its name.
17851 @deftp {Data Type} sddm-configuration
17852 This is the data type representing the SDDM service configuration.
17855 @item @code{display-server} (default: "x11")
17856 Select display server to use for the greeter. Valid values are
17857 @samp{"x11"} or @samp{"wayland"}.
17859 @item @code{numlock} (default: "on")
17860 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
17862 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
17863 Command to run when halting.
17865 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
17866 Command to run when rebooting.
17868 @item @code{theme} (default "maldives")
17869 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
17870 @samp{"maldives"} or @samp{"maya"}.
17872 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
17873 Directory to look for themes.
17875 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
17876 Directory to look for faces.
17878 @item @code{default-path} (default "/run/current-system/profile/bin")
17879 Default PATH to use.
17881 @item @code{minimum-uid} (default: 1000)
17882 Minimum UID displayed in SDDM and allowed for log-in.
17884 @item @code{maximum-uid} (default: 2000)
17885 Maximum UID to display in SDDM.
17887 @item @code{remember-last-user?} (default #t)
17888 Remember last user.
17890 @item @code{remember-last-session?} (default #t)
17891 Remember last session.
17893 @item @code{hide-users} (default "")
17894 Usernames to hide from SDDM greeter.
17896 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
17897 Users with shells listed will be hidden from the SDDM greeter.
17899 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
17900 Script to run before starting a wayland session.
17902 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
17903 Directory to look for desktop files starting wayland sessions.
17905 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17906 Configuration of the Xorg graphical server.
17908 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
17911 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
17914 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
17915 Script to run after starting xorg-server.
17917 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
17918 Script to run before stopping xorg-server.
17920 @item @code{xsession-command} (default: @code{xinitrc})
17921 Script to run before starting a X session.
17923 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
17924 Directory to look for desktop files starting X sessions.
17926 @item @code{minimum-vt} (default: 7)
17929 @item @code{auto-login-user} (default "")
17930 User to use for auto-login.
17932 @item @code{auto-login-session} (default "")
17933 Desktop file to use for auto-login.
17935 @item @code{relogin?} (default #f)
17936 Relogin after logout.
17941 @cindex login manager
17943 @defvr {Scheme Variable} sddm-service-type
17944 This is the type of the service to run the
17945 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
17946 must be a @code{sddm-configuration} record (see below).
17948 Here's an example use:
17951 (service sddm-service-type
17952 (sddm-configuration
17953 (auto-login-user "alice")
17954 (auto-login-session "xfce.desktop")))
17958 @deftp {Data Type} sddm-configuration
17959 This data type represents the configuration of the SDDM login manager.
17960 The available fields are:
17963 @item @code{sddm} (default: @code{sddm})
17964 The SDDM package to use.
17966 @item @code{display-server} (default: @code{"x11"})
17967 This must be either @code{"x11"} or @code{"wayland"}.
17969 @c FIXME: Add more fields.
17971 @item @code{auto-login-user} (default: @code{""})
17972 If non-empty, this is the user account under which to log in
17975 @item @code{auto-login-session} (default: @code{""})
17976 If non-empty, this is the @file{.desktop} file name to use as the
17977 auto-login session.
17981 @cindex Xorg, configuration
17982 @deftp {Data Type} xorg-configuration
17983 This data type represents the configuration of the Xorg graphical display
17984 server. Note that there is no Xorg service; instead, the X server is started
17985 by a ``display manager'' such as GDM, SDDM, and SLiM@. Thus, the configuration
17986 of these display managers aggregates an @code{xorg-configuration} record.
17989 @item @code{modules} (default: @code{%default-xorg-modules})
17990 This is a list of @dfn{module packages} loaded by the Xorg
17991 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
17993 @item @code{fonts} (default: @code{%default-xorg-fonts})
17994 This is a list of font directories to add to the server's @dfn{font path}.
17996 @item @code{drivers} (default: @code{'()})
17997 This must be either the empty list, in which case Xorg chooses a graphics
17998 driver automatically, or a list of driver names that will be tried in this
17999 order---e.g., @code{("modesetting" "vesa")}.
18001 @item @code{resolutions} (default: @code{'()})
18002 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
18003 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
18006 @cindex keyboard layout, for Xorg
18007 @cindex keymap, for Xorg
18008 @item @code{keyboard-layout} (default: @code{#f})
18009 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
18010 English (``qwerty'') for a 105-key PC keyboard.
18012 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
18013 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
18014 information on how to specify the keyboard layout.
18016 @item @code{extra-config} (default: @code{'()})
18017 This is a list of strings or objects appended to the configuration file. It
18018 is used to pass extra text to be added verbatim to the configuration file.
18020 @item @code{server} (default: @code{xorg-server})
18021 This is the package providing the Xorg server.
18023 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
18024 This is the list of command-line arguments to pass to the X server. The
18025 default is @code{-nolisten tcp}.
18029 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
18030 [@var{login-manager-service-type}]
18031 Tell the log-in manager (of type @var{login-manager-service-type}) to use
18032 @var{config}, an @code{<xorg-configuration>} record.
18034 Since the Xorg configuration is embedded in the log-in manager's
18035 configuration---e.g., @code{gdm-configuration}---this procedure provides a
18036 shorthand to set the Xorg configuration.
18039 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
18040 Return a @code{startx} script in which the modules, fonts, etc. specified
18041 in @var{config}, are available. The result should be used in place of
18044 Usually the X server is started by a login manager.
18048 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
18049 Add @var{package}, a package for a screen locker or screen saver whose
18050 command is @var{program}, to the set of setuid programs and add a PAM entry
18051 for it. For example:
18054 (screen-locker-service xlockmore "xlock")
18057 makes the good ol' XlockMore usable.
18061 @node Printing Services
18062 @subsection Printing Services
18064 @cindex printer support with CUPS
18065 The @code{(gnu services cups)} module provides a Guix service definition
18066 for the CUPS printing service. To add printer support to a Guix
18067 system, add a @code{cups-service} to the operating system definition:
18069 @deffn {Scheme Variable} cups-service-type
18070 The service type for the CUPS print server. Its value should be a valid
18071 CUPS configuration (see below). To use the default settings, simply
18074 (service cups-service-type)
18078 The CUPS configuration controls the basic things about your CUPS
18079 installation: what interfaces it listens on, what to do if a print job
18080 fails, how much logging to do, and so on. To actually add a printer,
18081 you have to visit the @url{http://localhost:631} URL, or use a tool such
18082 as GNOME's printer configuration services. By default, configuring a
18083 CUPS service will generate a self-signed certificate if needed, for
18084 secure connections to the print server.
18086 Suppose you want to enable the Web interface of CUPS and also add
18087 support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
18088 package and for HP printers @i{via} the @code{hplip-minimal} package.
18089 You can do that directly, like this (you need to use the
18090 @code{(gnu packages cups)} module):
18093 (service cups-service-type
18094 (cups-configuration
18095 (web-interface? #t)
18097 (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
18100 Note: If you wish to use the Qt5 based GUI which comes with the hplip
18101 package then it is suggested that you install the @code{hplip} package,
18102 either in your OS configuration file or as your user.
18104 The available configuration parameters follow. Each parameter
18105 definition is preceded by its type; for example, @samp{string-list foo}
18106 indicates that the @code{foo} parameter should be specified as a list of
18107 strings. There is also a way to specify the configuration as a string,
18108 if you have an old @code{cupsd.conf} file that you want to port over
18109 from some other system; see the end for more details.
18111 @c The following documentation was initially generated by
18112 @c (generate-documentation) in (gnu services cups). Manually maintained
18113 @c documentation is better, so we shouldn't hesitate to edit below as
18114 @c needed. However if the change you want to make to this documentation
18115 @c can be done in an automated way, it's probably easier to change
18116 @c (generate-documentation) than to make it below and have to deal with
18117 @c the churn as CUPS updates.
18120 Available @code{cups-configuration} fields are:
18122 @deftypevr {@code{cups-configuration} parameter} package cups
18126 @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list brlaser cups-filters epson-inkjet-printer-escpr foomatic-filters hplip-minimal splix)})
18127 Drivers and other extensions to the CUPS package.
18130 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
18131 Configuration of where to write logs, what directories to use for print
18132 spools, and related privileged configuration parameters.
18134 Available @code{files-configuration} fields are:
18136 @deftypevr {@code{files-configuration} parameter} log-location access-log
18137 Defines the access log filename. Specifying a blank filename disables
18138 access log generation. The value @code{stderr} causes log entries to be
18139 sent to the standard error file when the scheduler is running in the
18140 foreground, or to the system log daemon when run in the background. The
18141 value @code{syslog} causes log entries to be sent to the system log
18142 daemon. The server name may be included in filenames using the string
18143 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
18145 Defaults to @samp{"/var/log/cups/access_log"}.
18148 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
18149 Where CUPS should cache data.
18151 Defaults to @samp{"/var/cache/cups"}.
18154 @deftypevr {@code{files-configuration} parameter} string config-file-perm
18155 Specifies the permissions for all configuration files that the scheduler
18158 Note that the permissions for the printers.conf file are currently
18159 masked to only allow access from the scheduler user (typically root).
18160 This is done because printer device URIs sometimes contain sensitive
18161 authentication information that should not be generally known on the
18162 system. There is no way to disable this security feature.
18164 Defaults to @samp{"0640"}.
18167 @deftypevr {@code{files-configuration} parameter} log-location error-log
18168 Defines the error log filename. Specifying a blank filename disables
18169 error log generation. The value @code{stderr} causes log entries to be
18170 sent to the standard error file when the scheduler is running in the
18171 foreground, or to the system log daemon when run in the background. The
18172 value @code{syslog} causes log entries to be sent to the system log
18173 daemon. The server name may be included in filenames using the string
18174 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
18176 Defaults to @samp{"/var/log/cups/error_log"}.
18179 @deftypevr {@code{files-configuration} parameter} string fatal-errors
18180 Specifies which errors are fatal, causing the scheduler to exit. The
18185 No errors are fatal.
18188 All of the errors below are fatal.
18191 Browsing initialization errors are fatal, for example failed connections
18192 to the DNS-SD daemon.
18195 Configuration file syntax errors are fatal.
18198 Listen or Port errors are fatal, except for IPv6 failures on the
18199 loopback or @code{any} addresses.
18202 Log file creation or write errors are fatal.
18205 Bad startup file permissions are fatal, for example shared TLS
18206 certificate and key files with world-read permissions.
18209 Defaults to @samp{"all -browse"}.
18212 @deftypevr {@code{files-configuration} parameter} boolean file-device?
18213 Specifies whether the file pseudo-device can be used for new printer
18214 queues. The URI @uref{file:///dev/null} is always allowed.
18216 Defaults to @samp{#f}.
18219 @deftypevr {@code{files-configuration} parameter} string group
18220 Specifies the group name or ID that will be used when executing external
18223 Defaults to @samp{"lp"}.
18226 @deftypevr {@code{files-configuration} parameter} string log-file-perm
18227 Specifies the permissions for all log files that the scheduler writes.
18229 Defaults to @samp{"0644"}.
18232 @deftypevr {@code{files-configuration} parameter} log-location page-log
18233 Defines the page log filename. Specifying a blank filename disables
18234 page log generation. The value @code{stderr} causes log entries to be
18235 sent to the standard error file when the scheduler is running in the
18236 foreground, or to the system log daemon when run in the background. The
18237 value @code{syslog} causes log entries to be sent to the system log
18238 daemon. The server name may be included in filenames using the string
18239 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
18241 Defaults to @samp{"/var/log/cups/page_log"}.
18244 @deftypevr {@code{files-configuration} parameter} string remote-root
18245 Specifies the username that is associated with unauthenticated accesses
18246 by clients claiming to be the root user. The default is @code{remroot}.
18248 Defaults to @samp{"remroot"}.
18251 @deftypevr {@code{files-configuration} parameter} file-name request-root
18252 Specifies the directory that contains print jobs and other HTTP request
18255 Defaults to @samp{"/var/spool/cups"}.
18258 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
18259 Specifies the level of security sandboxing that is applied to print
18260 filters, backends, and other child processes of the scheduler; either
18261 @code{relaxed} or @code{strict}. This directive is currently only
18262 used/supported on macOS.
18264 Defaults to @samp{strict}.
18267 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
18268 Specifies the location of TLS certificates and private keys. CUPS will
18269 look for public and private keys in this directory: @file{.crt} files
18270 for PEM-encoded certificates and corresponding @file{.key} files for
18271 PEM-encoded private keys.
18273 Defaults to @samp{"/etc/cups/ssl"}.
18276 @deftypevr {@code{files-configuration} parameter} file-name server-root
18277 Specifies the directory containing the server configuration files.
18279 Defaults to @samp{"/etc/cups"}.
18282 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
18283 Specifies whether the scheduler calls fsync(2) after writing
18284 configuration or state files.
18286 Defaults to @samp{#f}.
18289 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
18290 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
18293 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
18294 Specifies the directory where temporary files are stored.
18296 Defaults to @samp{"/var/spool/cups/tmp"}.
18299 @deftypevr {@code{files-configuration} parameter} string user
18300 Specifies the user name or ID that is used when running external
18303 Defaults to @samp{"lp"}.
18306 @deftypevr {@code{files-configuration} parameter} string set-env
18307 Set the specified environment variable to be passed to child processes.
18309 Defaults to @samp{"variable value"}.
18313 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
18314 Specifies the logging level for the AccessLog file. The @code{config}
18315 level logs when printers and classes are added, deleted, or modified and
18316 when configuration files are accessed or updated. The @code{actions}
18317 level logs when print jobs are submitted, held, released, modified, or
18318 canceled, and any of the conditions for @code{config}. The @code{all}
18319 level logs all requests.
18321 Defaults to @samp{actions}.
18324 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
18325 Specifies whether to purge job history data automatically when it is no
18326 longer required for quotas.
18328 Defaults to @samp{#f}.
18331 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
18332 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
18333 For example, @samp{"_cups" "_print"} will tell network clients that both
18334 CUPS sharing and IPP Everywhere are supported.
18336 Defaults to @samp{"_cups"}.
18339 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
18340 Specifies which protocols to use for local printer sharing.
18342 Defaults to @samp{dnssd}.
18345 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
18346 Specifies whether the CUPS web interface is advertised.
18348 Defaults to @samp{#f}.
18351 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
18352 Specifies whether shared printers are advertised.
18354 Defaults to @samp{#f}.
18357 @deftypevr {@code{cups-configuration} parameter} string classification
18358 Specifies the security classification of the server. Any valid banner
18359 name can be used, including @samp{"classified"}, @samp{"confidential"},
18360 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
18361 banner can be omitted to disable secure printing functions.
18363 Defaults to @samp{""}.
18366 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
18367 Specifies whether users may override the classification (cover page) of
18368 individual print jobs using the @code{job-sheets} option.
18370 Defaults to @samp{#f}.
18373 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
18374 Specifies the default type of authentication to use.
18376 Defaults to @samp{Basic}.
18379 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
18380 Specifies whether encryption will be used for authenticated requests.
18382 Defaults to @samp{Required}.
18385 @deftypevr {@code{cups-configuration} parameter} string default-language
18386 Specifies the default language to use for text and web content.
18388 Defaults to @samp{"en"}.
18391 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
18392 Specifies the default paper size for new print queues. @samp{"Auto"}
18393 uses a locale-specific default, while @samp{"None"} specifies there is
18394 no default paper size. Specific size names are typically
18395 @samp{"Letter"} or @samp{"A4"}.
18397 Defaults to @samp{"Auto"}.
18400 @deftypevr {@code{cups-configuration} parameter} string default-policy
18401 Specifies the default access policy to use.
18403 Defaults to @samp{"default"}.
18406 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
18407 Specifies whether local printers are shared by default.
18409 Defaults to @samp{#t}.
18412 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
18413 Specifies the delay for updating of configuration and state files, in
18414 seconds. A value of 0 causes the update to happen as soon as possible,
18415 typically within a few milliseconds.
18417 Defaults to @samp{30}.
18420 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
18421 Specifies what to do when an error occurs. Possible values are
18422 @code{abort-job}, which will discard the failed print job;
18423 @code{retry-job}, which will retry the job at a later time;
18424 @code{retry-current-job}, which retries the failed job immediately; and
18425 @code{stop-printer}, which stops the printer.
18427 Defaults to @samp{stop-printer}.
18430 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
18431 Specifies the maximum cost of filters that are run concurrently, which
18432 can be used to minimize disk, memory, and CPU resource problems. A
18433 limit of 0 disables filter limiting. An average print to a
18434 non-PostScript printer needs a filter limit of about 200. A PostScript
18435 printer needs about half that (100). Setting the limit below these
18436 thresholds will effectively limit the scheduler to printing a single job
18439 Defaults to @samp{0}.
18442 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
18443 Specifies the scheduling priority of filters that are run to print a
18444 job. The nice value ranges from 0, the highest priority, to 19, the
18447 Defaults to @samp{0}.
18450 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
18451 Specifies whether to do reverse lookups on connecting clients. The
18452 @code{double} setting causes @code{cupsd} to verify that the hostname
18453 resolved from the address matches one of the addresses returned for that
18454 hostname. Double lookups also prevent clients with unregistered
18455 addresses from connecting to your server. Only set this option to
18456 @code{#t} or @code{double} if absolutely required.
18458 Defaults to @samp{#f}.
18461 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
18462 Specifies the number of seconds to wait before killing the filters and
18463 backend associated with a canceled or held job.
18465 Defaults to @samp{30}.
18468 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
18469 Specifies the interval between retries of jobs in seconds. This is
18470 typically used for fax queues but can also be used with normal print
18471 queues whose error policy is @code{retry-job} or
18472 @code{retry-current-job}.
18474 Defaults to @samp{30}.
18477 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
18478 Specifies the number of retries that are done for jobs. This is
18479 typically used for fax queues but can also be used with normal print
18480 queues whose error policy is @code{retry-job} or
18481 @code{retry-current-job}.
18483 Defaults to @samp{5}.
18486 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
18487 Specifies whether to support HTTP keep-alive connections.
18489 Defaults to @samp{#t}.
18492 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
18493 Specifies how long an idle client connection remains open, in seconds.
18495 Defaults to @samp{30}.
18498 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
18499 Specifies the maximum size of print files, IPP requests, and HTML form
18500 data. A limit of 0 disables the limit check.
18502 Defaults to @samp{0}.
18505 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
18506 Listens on the specified interfaces for connections. Valid values are
18507 of the form @var{address}:@var{port}, where @var{address} is either an
18508 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
18509 indicate all addresses. Values can also be file names of local UNIX
18510 domain sockets. The Listen directive is similar to the Port directive
18511 but allows you to restrict access to specific interfaces or networks.
18514 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
18515 Specifies the number of pending connections that will be allowed. This
18516 normally only affects very busy servers that have reached the MaxClients
18517 limit, but can also be triggered by large numbers of simultaneous
18518 connections. When the limit is reached, the operating system will
18519 refuse additional connections until the scheduler can accept the pending
18522 Defaults to @samp{128}.
18525 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
18526 Specifies a set of additional access controls.
18528 Available @code{location-access-controls} fields are:
18530 @deftypevr {@code{location-access-controls} parameter} file-name path
18531 Specifies the URI path to which the access control applies.
18534 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
18535 Access controls for all access to this path, in the same format as the
18536 @code{access-controls} of @code{operation-access-control}.
18538 Defaults to @samp{()}.
18541 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
18542 Access controls for method-specific access to this path.
18544 Defaults to @samp{()}.
18546 Available @code{method-access-controls} fields are:
18548 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
18549 If @code{#t}, apply access controls to all methods except the listed
18550 methods. Otherwise apply to only the listed methods.
18552 Defaults to @samp{#f}.
18555 @deftypevr {@code{method-access-controls} parameter} method-list methods
18556 Methods to which this access control applies.
18558 Defaults to @samp{()}.
18561 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
18562 Access control directives, as a list of strings. Each string should be
18563 one directive, such as @samp{"Order allow,deny"}.
18565 Defaults to @samp{()}.
18570 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
18571 Specifies the number of debugging messages that are retained for logging
18572 if an error occurs in a print job. Debug messages are logged regardless
18573 of the LogLevel setting.
18575 Defaults to @samp{100}.
18578 @deftypevr {@code{cups-configuration} parameter} log-level log-level
18579 Specifies the level of logging for the ErrorLog file. The value
18580 @code{none} stops all logging while @code{debug2} logs everything.
18582 Defaults to @samp{info}.
18585 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
18586 Specifies the format of the date and time in the log files. The value
18587 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
18589 Defaults to @samp{standard}.
18592 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
18593 Specifies the maximum number of simultaneous clients that are allowed by
18596 Defaults to @samp{100}.
18599 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
18600 Specifies the maximum number of simultaneous clients that are allowed
18601 from a single address.
18603 Defaults to @samp{100}.
18606 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
18607 Specifies the maximum number of copies that a user can print of each
18610 Defaults to @samp{9999}.
18613 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
18614 Specifies the maximum time a job may remain in the @code{indefinite}
18615 hold state before it is canceled. A value of 0 disables cancellation of
18618 Defaults to @samp{0}.
18621 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
18622 Specifies the maximum number of simultaneous jobs that are allowed. Set
18623 to 0 to allow an unlimited number of jobs.
18625 Defaults to @samp{500}.
18628 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
18629 Specifies the maximum number of simultaneous jobs that are allowed per
18630 printer. A value of 0 allows up to MaxJobs jobs per printer.
18632 Defaults to @samp{0}.
18635 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
18636 Specifies the maximum number of simultaneous jobs that are allowed per
18637 user. A value of 0 allows up to MaxJobs jobs per user.
18639 Defaults to @samp{0}.
18642 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
18643 Specifies the maximum time a job may take to print before it is
18644 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
18646 Defaults to @samp{10800}.
18649 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
18650 Specifies the maximum size of the log files before they are rotated, in
18651 bytes. The value 0 disables log rotation.
18653 Defaults to @samp{1048576}.
18656 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
18657 Specifies the maximum amount of time to allow between files in a
18658 multiple file print job, in seconds.
18660 Defaults to @samp{300}.
18663 @deftypevr {@code{cups-configuration} parameter} string page-log-format
18664 Specifies the format of PageLog lines. Sequences beginning with percent
18665 (@samp{%}) characters are replaced with the corresponding information,
18666 while all other characters are copied literally. The following percent
18667 sequences are recognized:
18671 insert a single percent character
18674 insert the value of the specified IPP attribute
18677 insert the number of copies for the current page
18680 insert the current page number
18683 insert the current date and time in common log format
18689 insert the printer name
18692 insert the username
18695 A value of the empty string disables page logging. The string @code{%p
18696 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
18697 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
18700 Defaults to @samp{""}.
18703 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
18704 Passes the specified environment variable(s) to child processes; a list
18707 Defaults to @samp{()}.
18710 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
18711 Specifies named access control policies.
18713 Available @code{policy-configuration} fields are:
18715 @deftypevr {@code{policy-configuration} parameter} string name
18716 Name of the policy.
18719 @deftypevr {@code{policy-configuration} parameter} string job-private-access
18720 Specifies an access list for a job's private values. @code{@@ACL} maps
18721 to the printer's requesting-user-name-allowed or
18722 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18723 owner. @code{@@SYSTEM} maps to the groups listed for the
18724 @code{system-group} field of the @code{files-config} configuration,
18725 which is reified into the @code{cups-files.conf(5)} file. Other
18726 possible elements of the access list include specific user names, and
18727 @code{@@@var{group}} to indicate members of a specific group. The
18728 access list may also be simply @code{all} or @code{default}.
18730 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18733 @deftypevr {@code{policy-configuration} parameter} string job-private-values
18734 Specifies the list of job values to make private, or @code{all},
18735 @code{default}, or @code{none}.
18737 Defaults to @samp{"job-name job-originating-host-name
18738 job-originating-user-name phone"}.
18741 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
18742 Specifies an access list for a subscription's private values.
18743 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
18744 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18745 owner. @code{@@SYSTEM} maps to the groups listed for the
18746 @code{system-group} field of the @code{files-config} configuration,
18747 which is reified into the @code{cups-files.conf(5)} file. Other
18748 possible elements of the access list include specific user names, and
18749 @code{@@@var{group}} to indicate members of a specific group. The
18750 access list may also be simply @code{all} or @code{default}.
18752 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18755 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
18756 Specifies the list of job values to make private, or @code{all},
18757 @code{default}, or @code{none}.
18759 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
18760 notify-subscriber-user-name notify-user-data"}.
18763 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
18764 Access control by IPP operation.
18766 Defaults to @samp{()}.
18770 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
18771 Specifies whether job files (documents) are preserved after a job is
18772 printed. If a numeric value is specified, job files are preserved for
18773 the indicated number of seconds after printing. Otherwise a boolean
18774 value applies indefinitely.
18776 Defaults to @samp{86400}.
18779 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
18780 Specifies whether the job history is preserved after a job is printed.
18781 If a numeric value is specified, the job history is preserved for the
18782 indicated number of seconds after printing. If @code{#t}, the job
18783 history is preserved until the MaxJobs limit is reached.
18785 Defaults to @samp{#t}.
18788 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
18789 Specifies the amount of time to wait for job completion before
18790 restarting the scheduler.
18792 Defaults to @samp{30}.
18795 @deftypevr {@code{cups-configuration} parameter} string rip-cache
18796 Specifies the maximum amount of memory to use when converting documents
18797 into bitmaps for a printer.
18799 Defaults to @samp{"128m"}.
18802 @deftypevr {@code{cups-configuration} parameter} string server-admin
18803 Specifies the email address of the server administrator.
18805 Defaults to @samp{"root@@localhost.localdomain"}.
18808 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
18809 The ServerAlias directive is used for HTTP Host header validation when
18810 clients connect to the scheduler from external interfaces. Using the
18811 special name @code{*} can expose your system to known browser-based DNS
18812 rebinding attacks, even when accessing sites through a firewall. If the
18813 auto-discovery of alternate names does not work, we recommend listing
18814 each alternate name with a ServerAlias directive instead of using
18817 Defaults to @samp{*}.
18820 @deftypevr {@code{cups-configuration} parameter} string server-name
18821 Specifies the fully-qualified host name of the server.
18823 Defaults to @samp{"localhost"}.
18826 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
18827 Specifies what information is included in the Server header of HTTP
18828 responses. @code{None} disables the Server header. @code{ProductOnly}
18829 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
18830 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
18831 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
18832 the output of the @code{uname} command. @code{Full} reports @code{CUPS
18833 2.0.0 (@var{uname}) IPP/2.0}.
18835 Defaults to @samp{Minimal}.
18838 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
18839 Listens on the specified interfaces for encrypted connections. Valid
18840 values are of the form @var{address}:@var{port}, where @var{address} is
18841 either an IPv6 address enclosed in brackets, an IPv4 address, or
18842 @code{*} to indicate all addresses.
18844 Defaults to @samp{()}.
18847 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
18848 Sets encryption options. By default, CUPS only supports encryption
18849 using TLS v1.0 or higher using known secure cipher suites. Security is
18850 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
18851 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
18852 suites, which are required for some older clients. The @code{AllowSSL3} option
18853 enables SSL v3.0, which is required for some older clients that do not support
18854 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
18855 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
18856 protocol version to TLS v1.1.
18858 Defaults to @samp{()}.
18861 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
18862 Specifies whether the scheduler requires clients to strictly adhere to
18863 the IPP specifications.
18865 Defaults to @samp{#f}.
18868 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
18869 Specifies the HTTP request timeout, in seconds.
18871 Defaults to @samp{300}.
18875 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
18876 Specifies whether the web interface is enabled.
18878 Defaults to @samp{#f}.
18881 At this point you're probably thinking ``oh dear, Guix manual, I like
18882 you but you can stop already with the configuration options''. Indeed.
18883 However, one more point: it could be that you have an existing
18884 @code{cupsd.conf} that you want to use. In that case, you can pass an
18885 @code{opaque-cups-configuration} as the configuration of a
18886 @code{cups-service-type}.
18888 Available @code{opaque-cups-configuration} fields are:
18890 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
18894 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
18895 The contents of the @code{cupsd.conf}, as a string.
18898 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
18899 The contents of the @code{cups-files.conf} file, as a string.
18902 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
18903 strings of the same name, you could instantiate a CUPS service like
18907 (service cups-service-type
18908 (opaque-cups-configuration
18909 (cupsd.conf cupsd.conf)
18910 (cups-files.conf cups-files.conf)))
18914 @node Desktop Services
18915 @subsection Desktop Services
18917 The @code{(gnu services desktop)} module provides services that are
18918 usually useful in the context of a ``desktop'' setup---that is, on a
18919 machine running a graphical display server, possibly with graphical user
18920 interfaces, etc. It also defines services that provide specific desktop
18921 environments like GNOME, Xfce or MATE.
18923 To simplify things, the module defines a variable containing the set of
18924 services that users typically expect on a machine with a graphical
18925 environment and networking:
18927 @defvr {Scheme Variable} %desktop-services
18928 This is a list of services that builds upon @code{%base-services} and
18929 adds or adjusts services for a typical ``desktop'' setup.
18931 In particular, it adds a graphical login manager (@pxref{X Window,
18932 @code{gdm-service-type}}), screen lockers, a network management tool
18933 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
18934 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
18935 energy and color management services, the @code{elogind} login and seat
18936 manager, the Polkit privilege service, the GeoClue location service, the
18937 AccountsService daemon that allows authorized users change system passwords,
18938 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
18939 name service switch service configured to be able to use @code{nss-mdns}
18940 (@pxref{Name Service Switch, mDNS}).
18943 The @code{%desktop-services} variable can be used as the @code{services}
18944 field of an @code{operating-system} declaration (@pxref{operating-system
18945 Reference, @code{services}}).
18947 Additionally, the @code{gnome-desktop-service-type},
18948 @code{xfce-desktop-service}, @code{mate-desktop-service-type},
18949 @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
18950 procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
18951 ``add GNOME'' means that system-level services like the backlight adjustment
18952 helpers and the power management utilities are added to the system, extending
18953 @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
18954 elevated privileges on a limited number of special-purpose system interfaces.
18955 Additionally, adding a service made by @code{gnome-desktop-service-type} adds
18956 the GNOME metapackage to the system profile. Likewise, adding the Xfce
18957 service not only adds the @code{xfce} metapackage to the system profile, but
18958 it also gives the Thunar file manager the ability to open a ``root-mode'' file
18959 management window, if the user authenticates using the administrator's
18960 password via the standard polkit graphical interface. To ``add MATE'' means
18961 that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
18962 to operate with elevated privileges on a limited number of special-purpose
18963 system interfaces. Additionally, adding a service of type
18964 @code{mate-desktop-service-type} adds the MATE metapackage to the system
18965 profile. ``Adding Enlightenment'' means that @code{dbus} is extended
18966 appropriately, and several of Enlightenment's binaries are set as setuid,
18967 allowing Enlightenment's screen locker and other functionality to work as
18970 The desktop environments in Guix use the Xorg display server by
18971 default. If you'd like to use the newer display server protocol
18972 called Wayland, you need to use the @code{sddm-service} instead of
18973 GDM as the graphical login manager. You should then
18974 select the ``GNOME (Wayland)'' session in SDDM@. Alternatively you can
18975 also try starting GNOME on Wayland manually from a TTY with the
18976 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
18977 gnome-session``. Currently only GNOME has support for Wayland.
18979 @defvr {Scheme Variable} gnome-desktop-service-type
18980 This is the type of the service that adds the @uref{https://www.gnome.org,
18981 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
18982 object (see below).
18984 This service adds the @code{gnome} package to the system profile, and extends
18985 polkit with the actions from @code{gnome-settings-daemon}.
18988 @deftp {Data Type} gnome-desktop-configuration
18989 Configuration record for the GNOME desktop environment.
18992 @item @code{gnome} (default: @code{gnome})
18993 The GNOME package to use.
18997 @defvr {Scheme Variable} xfce-desktop-service-type
18998 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
18999 desktop environment. Its value is an @code{xfce-desktop-configuration} object
19002 This service adds the @code{xfce} package to the system profile, and
19003 extends polkit with the ability for @code{thunar} to manipulate the file
19004 system as root from within a user session, after the user has authenticated
19005 with the administrator's password.
19007 Note that @code{xfce4-panel} and its plugin packages should be installed in
19008 the same profile to ensure compatibility. When using this service, you should
19009 add extra plugins (@code{xfce4-whiskermenu-plugin},
19010 @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
19011 @code{operating-system}.
19014 @deftp {Data Type} xfce-desktop-configuration
19015 Configuration record for the Xfce desktop environment.
19018 @item @code{xfce} (default: @code{xfce})
19019 The Xfce package to use.
19023 @deffn {Scheme Variable} mate-desktop-service-type
19024 This is the type of the service that runs the @uref{https://mate-desktop.org/,
19025 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
19026 object (see below).
19028 This service adds the @code{mate} package to the system
19029 profile, and extends polkit with the actions from
19030 @code{mate-settings-daemon}.
19033 @deftp {Data Type} mate-desktop-configuration
19034 Configuration record for the MATE desktop environment.
19037 @item @code{mate} (default: @code{mate})
19038 The MATE package to use.
19042 @deffn {Scheme Variable} lxqt-desktop-service-type
19043 This is the type of the service that runs the @uref{https://lxqt.github.io,
19044 LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
19045 object (see below).
19047 This service adds the @code{lxqt} package to the system
19051 @deftp {Data Type} lxqt-desktop-configuration
19052 Configuration record for the LXQt desktop environment.
19055 @item @code{lxqt} (default: @code{lxqt})
19056 The LXQT package to use.
19060 @deffn {Scheme Variable} enlightenment-desktop-service-type
19061 Return a service that adds the @code{enlightenment} package to the system
19062 profile, and extends dbus with actions from @code{efl}.
19065 @deftp {Data Type} enlightenment-desktop-service-configuration
19067 @item @code{enlightenment} (default: @code{enlightenment})
19068 The enlightenment package to use.
19072 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
19073 the default @code{%desktop-services} variable doesn't include any of
19074 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
19075 @code{%desktop-services} in the @code{services} field of your
19076 @code{operating-system}:
19079 (use-modules (gnu))
19080 (use-service-modules desktop)
19083 ;; cons* adds items to the list given as its last argument.
19084 (services (cons* (service gnome-desktop-service-type)
19085 (service xfce-desktop-service)
19086 %desktop-services))
19090 These desktop environments will then be available as options in the
19091 graphical login window.
19093 The actual service definitions included in @code{%desktop-services} and
19094 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
19095 are described below.
19097 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
19098 Return a service that runs the ``system bus'', using @var{dbus}, with
19099 support for @var{services}.
19101 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
19102 facility. Its system bus is used to allow system services to communicate
19103 and to be notified of system-wide events.
19105 @var{services} must be a list of packages that provide an
19106 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
19107 and policy files. For example, to allow avahi-daemon to use the system bus,
19108 @var{services} must be equal to @code{(list avahi)}.
19111 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
19112 Return a service that runs the @code{elogind} login and
19113 seat management daemon. @uref{https://github.com/elogind/elogind,
19114 Elogind} exposes a D-Bus interface that can be used to know which users
19115 are logged in, know what kind of sessions they have open, suspend the
19116 system, inhibit system suspend, reboot the system, and other tasks.
19118 Elogind handles most system-level power events for a computer, for
19119 example suspending the system when a lid is closed, or shutting it down
19120 when the power button is pressed.
19122 The @var{config} keyword argument specifies the configuration for
19123 elogind, and should be the result of an @code{(elogind-configuration
19124 (@var{parameter} @var{value})...)} invocation. Available parameters and
19125 their default values are:
19128 @item kill-user-processes?
19130 @item kill-only-users
19132 @item kill-exclude-users
19134 @item inhibit-delay-max-seconds
19136 @item handle-power-key
19138 @item handle-suspend-key
19140 @item handle-hibernate-key
19142 @item handle-lid-switch
19144 @item handle-lid-switch-docked
19146 @item handle-lid-switch-external-power
19148 @item power-key-ignore-inhibited?
19150 @item suspend-key-ignore-inhibited?
19152 @item hibernate-key-ignore-inhibited?
19154 @item lid-switch-ignore-inhibited?
19156 @item holdoff-timeout-seconds
19160 @item idle-action-seconds
19162 @item runtime-directory-size-percent
19164 @item runtime-directory-size
19168 @item suspend-state
19169 @code{("mem" "standby" "freeze")}
19172 @item hibernate-state
19174 @item hibernate-mode
19175 @code{("platform" "shutdown")}
19176 @item hybrid-sleep-state
19178 @item hybrid-sleep-mode
19179 @code{("suspend" "platform" "shutdown")}
19183 @deffn {Scheme Procedure} accountsservice-service @
19184 [#:accountsservice @var{accountsservice}]
19185 Return a service that runs AccountsService, a system service that can
19186 list available accounts, change their passwords, and so on.
19187 AccountsService integrates with PolicyKit to enable unprivileged users
19188 to acquire the capability to modify their system configuration.
19189 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
19190 accountsservice web site} for more information.
19192 The @var{accountsservice} keyword argument is the @code{accountsservice}
19193 package to expose as a service.
19196 @deffn {Scheme Procedure} polkit-service @
19197 [#:polkit @var{polkit}]
19198 Return a service that runs the
19199 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
19200 management service}, which allows system administrators to grant access to
19201 privileged operations in a structured way. By querying the Polkit service, a
19202 privileged system component can know when it should grant additional
19203 capabilities to ordinary users. For example, an ordinary user can be granted
19204 the capability to suspend the system if the user is logged in locally.
19207 @defvr {Scheme Variable} polkit-wheel-service
19208 Service that adds the @code{wheel} group as admins to the Polkit
19209 service. This makes it so that users in the @code{wheel} group are queried
19210 for their own passwords when performing administrative actions instead of
19211 @code{root}'s, similar to the behaviour used by @code{sudo}.
19214 @defvr {Scheme Variable} upower-service-type
19215 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
19216 system-wide monitor for power consumption and battery levels, with the given
19217 configuration settings.
19219 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
19220 notably used by GNOME.
19223 @deftp {Data Type} upower-configuration
19224 Data type representation the configuration for UPower.
19228 @item @code{upower} (default: @var{upower})
19229 Package to use for @code{upower}.
19231 @item @code{watts-up-pro?} (default: @code{#f})
19232 Enable the Watts Up Pro device.
19234 @item @code{poll-batteries?} (default: @code{#t})
19235 Enable polling the kernel for battery level changes.
19237 @item @code{ignore-lid?} (default: @code{#f})
19238 Ignore the lid state, this can be useful if it's incorrect on a device.
19240 @item @code{use-percentage-for-policy?} (default: @code{#f})
19241 Whether battery percentage based policy should be used. The default is to use
19242 the time left, change to @code{#t} to use the percentage.
19244 @item @code{percentage-low} (default: @code{10})
19245 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19246 at which the battery is considered low.
19248 @item @code{percentage-critical} (default: @code{3})
19249 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19250 at which the battery is considered critical.
19252 @item @code{percentage-action} (default: @code{2})
19253 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19254 at which action will be taken.
19256 @item @code{time-low} (default: @code{1200})
19257 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19258 seconds at which the battery is considered low.
19260 @item @code{time-critical} (default: @code{300})
19261 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19262 seconds at which the battery is considered critical.
19264 @item @code{time-action} (default: @code{120})
19265 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19266 seconds at which action will be taken.
19268 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
19269 The action taken when @code{percentage-action} or @code{time-action} is
19270 reached (depending on the configuration of @code{use-percentage-for-policy?}).
19272 Possible values are:
19282 @code{'hybrid-sleep}.
19288 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
19289 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
19290 UDisks}, a @dfn{disk management} daemon that provides user interfaces
19291 with notifications and ways to mount/unmount disks. Programs that talk
19292 to UDisks include the @command{udisksctl} command, part of UDisks, and
19293 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
19294 it will only be able to use the file-system utilities installed in the
19295 system profile. For example if you want to be able to mount NTFS
19296 file-systems in read and write fashion, you'll need to have
19297 @code{ntfs-3g} installed system-wide.
19300 @deffn {Scheme Variable} colord-service-type
19301 This is the type of the service that runs @command{colord}, a system
19302 service with a D-Bus
19303 interface to manage the color profiles of input and output devices such as
19304 screens and scanners. It is notably used by the GNOME Color Manager graphical
19305 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
19306 site} for more information.
19309 @cindex scanner access
19310 @defvr {Scheme Variable} sane-service-type
19311 This service provides access to scanners @i{via}
19312 @uref{http://www.sane-project.org, SANE} by installing the necessary
19313 udev rules. It is included in @code{%desktop-services} (@pxref{Desktop
19314 Services}) and relies by default on @code{sane-backends-minimal} package
19315 (see below) for hardware support.
19318 @defvr {Scheme Variable} sane-backends-minimal
19319 The default package which the @code{sane-service-type} installs. It
19320 supports many recent scanners.
19323 @defvr {Scheme Variable} sane-backends
19324 This package includes support for all scanners that
19325 @code{sane-backends-minimal} supports, plus older Hewlett-Packard
19326 scanners supported by @code{hplip} package. In order to use this on
19327 a system which relies on @code{%desktop-services}, you may use
19328 @code{modify-services} (@pxref{Service Reference,
19329 @code{modify-services}}) as illustrated below:
19332 (use-modules (gnu))
19333 (use-service-modules
19336 (use-package-modules
19340 (define %my-desktop-services
19341 ;; List of desktop services that supports a broader range of scanners.
19342 (modify-services %desktop-services
19343 (sane-service-type _ => sane-backends)))
19347 (services %my-desktop-services)
19351 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
19352 Return a configuration allowing an application to access GeoClue
19353 location data. @var{name} is the Desktop ID of the application, without
19354 the @code{.desktop} part. If @var{allowed?} is true, the application
19355 will have access to location information by default. The boolean
19356 @var{system?} value indicates whether an application is a system component
19357 or not. Finally @var{users} is a list of UIDs of all users for which
19358 this application is allowed location info access. An empty users list
19359 means that all users are allowed.
19362 @defvr {Scheme Variable} %standard-geoclue-applications
19363 The standard list of well-known GeoClue application configurations,
19364 granting authority to the GNOME date-and-time utility to ask for the
19365 current location in order to set the time zone, and allowing the
19366 IceCat and Epiphany web browsers to request location information.
19367 IceCat and Epiphany both query the user before allowing a web page to
19368 know the user's location.
19371 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
19372 [#:whitelist '()] @
19373 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
19374 [#:submit-data? #f]
19375 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
19376 [#:submission-nick "geoclue"] @
19377 [#:applications %standard-geoclue-applications]
19378 Return a service that runs the GeoClue location service. This service
19379 provides a D-Bus interface to allow applications to request access to a
19380 user's physical location, and optionally to add information to online
19381 location databases. See
19382 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
19383 web site} for more information.
19386 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
19387 [@w{#:auto-enable? #f}]
19388 Return a service that runs the @command{bluetoothd} daemon, which
19389 manages all the Bluetooth devices and provides a number of D-Bus
19390 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
19391 powered automatically at boot, which can be useful when using a
19392 bluetooth keyboard or mouse.
19394 Users need to be in the @code{lp} group to access the D-Bus service.
19397 @defvr {Scheme Variable} gnome-keyring-service-type
19398 This is the type of the service that adds the
19399 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
19400 value is a @code{gnome-keyring-configuration} object (see below).
19402 This service adds the @code{gnome-keyring} package to the system profile
19403 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
19404 a user's login keyring when they log in or setting its password with passwd.
19407 @deftp {Data Type} gnome-keyring-configuration
19408 Configuration record for the GNOME Keyring service.
19411 @item @code{keyring} (default: @code{gnome-keyring})
19412 The GNOME keyring package to use.
19414 @item @code{pam-services}
19415 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
19416 services to extend, where @var{service} is the name of an existing
19417 service to extend and @var{kind} is one of @code{login} or
19420 If @code{login} is given, it adds an optional
19421 @code{pam_gnome_keyring.so} to the auth block without arguments and to
19422 the session block with @code{auto_start}. If @code{passwd} is given, it
19423 adds an optional @code{pam_gnome_keyring.so} to the password block
19426 By default, this field contains ``gdm-password'' with the value @code{login}
19427 and ``passwd'' is with the value @code{passwd}.
19432 @node Sound Services
19433 @subsection Sound Services
19435 @cindex sound support
19437 @cindex PulseAudio, sound support
19439 The @code{(gnu services sound)} module provides a service to configure the
19440 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
19441 preferred ALSA output driver.
19443 @deffn {Scheme Variable} alsa-service-type
19444 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
19445 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
19446 configuration file. The value for this type is a @command{alsa-configuration}
19447 record as in this example:
19450 (service alsa-service-type)
19453 See below for details about @code{alsa-configuration}.
19456 @deftp {Data Type} alsa-configuration
19457 Data type representing the configuration for @code{alsa-service}.
19460 @item @code{alsa-plugins} (default: @var{alsa-plugins})
19461 @code{alsa-plugins} package to use.
19463 @item @code{pulseaudio?} (default: @var{#t})
19464 Whether ALSA applications should transparently be made to use the
19465 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
19467 Using PulseAudio allows you to run several sound-producing applications
19468 at the same time and to individual control them @i{via}
19469 @command{pavucontrol}, among other things.
19471 @item @code{extra-options} (default: @var{""})
19472 String to append to the @file{/etc/asound.conf} file.
19477 Individual users who want to override the system configuration of ALSA can do
19478 it with the @file{~/.asoundrc} file:
19481 # In guix, we have to specify the absolute path for plugins.
19483 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
19486 # Routing ALSA to jack:
19487 # <http://jackaudio.org/faq/routing_alsa.html>.
19491 0 system:playback_1
19492 1 system:playback_2
19509 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
19512 @deffn {Scheme Variable} pulseaudio-service-type
19513 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
19514 sound server. It exists to allow system overrides of the default settings
19515 via @code{pulseaudio-configuration}, see below.
19518 This service overrides per-user configuration files. If you want
19519 PulseAudio to honor configuration files in @file{~/.config/pulse} you
19520 have to unset the environment variables @env{PULSE_CONFIG} and
19521 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
19525 This service on its own does not ensure, that the @code{pulseaudio} package
19526 exists on your machine. It merely adds configuration files for it, as
19527 detailed below. In the (admittedly unlikely) case, that you find yourself
19528 without a @code{pulseaudio} package, consider enabling it through the
19529 @code{alsa-service-type} above.
19533 @deftp {Data Type} pulseaudio-configuration
19534 Data type representing the configuration for @code{pulseaudio-service}.
19537 @item @code{client-conf} (default: @code{'()})
19538 List of settings to set in @file{client.conf}.
19539 Accepts a list of strings or a symbol-value pairs. A string will be
19540 inserted as-is with a newline added. A pair will be formatted as
19541 ``key = value'', again with a newline added.
19543 @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
19544 List of settings to set in @file{daemon.conf}, formatted just like
19547 @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
19548 Script file to use as @file{default.pa}.
19550 @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
19551 Script file to use as @file{system.pa}.
19555 @deffn {Scheme Variable} ladspa-service-type
19556 This service sets the @var{LADSPA_PATH} variable, so that programs, which
19557 respect it, e.g. PulseAudio, can load LADSPA plugins.
19559 The following example will setup the service to enable modules from the
19560 @code{swh-plugins} package:
19563 (service ladspa-service-type
19564 (ladspa-configuration (plugins (list swh-plugins))))
19567 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
19572 @node Database Services
19573 @subsection Database Services
19577 The @code{(gnu services databases)} module provides the following services.
19579 @subsubheading PostgreSQL
19581 The following example describes a PostgreSQL service with the default
19585 (service postgresql-service-type
19586 (postgresql-configuration
19587 (postgresql postgresql-10)))
19590 If the services fails to start, it may be due to an incompatible
19591 cluster already present in @var{data-directory}. Adjust it (or, if you
19592 don't need the cluster anymore, delete @var{data-directory}), then
19593 restart the service.
19595 Peer authentication is used by default and the @code{postgres} user
19596 account has no shell, which prevents the direct execution of @code{psql}
19597 commands as this user. To use @code{psql}, you can temporarily log in
19598 as @code{postgres} using a shell, create a PostgreSQL superuser with the
19599 same name as one of the system users and then create the associated
19603 sudo -u postgres -s /bin/sh
19604 createuser --interactive
19605 createdb $MY_USER_LOGIN # Replace appropriately.
19608 @deftp {Data Type} postgresql-configuration
19609 Data type representing the configuration for the
19610 @code{postgresql-service-type}.
19613 @item @code{postgresql}
19614 PostgreSQL package to use for the service.
19616 @item @code{port} (default: @code{5432})
19617 Port on which PostgreSQL should listen.
19619 @item @code{locale} (default: @code{"en_US.utf8"})
19620 Locale to use as the default when creating the database cluster.
19622 @item @code{config-file} (default: @code{(postgresql-config-file)})
19623 The configuration file to use when running PostgreSQL@. The default
19624 behaviour uses the postgresql-config-file record with the default values
19627 @item @code{log-directory} (default: @code{"/var/log/postgresql"})
19628 The directory where @command{pg_ctl} output will be written in a file
19629 named @code{"pg_ctl.log"}. This file can be useful to debug PostgreSQL
19630 configuration errors for instance.
19632 @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
19633 Directory in which to store the data.
19635 @item @code{extension-packages} (default: @code{'()})
19636 @cindex postgresql extension-packages
19637 Additional extensions are loaded from packages listed in
19638 @var{extension-packages}. Extensions are available at runtime. For instance,
19639 to create a geographic database using the @code{postgis} extension, a user can
19640 configure the postgresql-service as in this example:
19644 (use-package-modules databases geo)
19648 ;; postgresql is required to run `psql' but postgis is not required for
19649 ;; proper operation.
19650 (packages (cons* postgresql %base-packages))
19653 (service postgresql-service-type
19654 (postgresql-configuration
19655 (postgresql postgresql-10)
19656 (extension-packages (list postgis))))
19660 Then the extension becomes visible and you can initialise an empty geographic
19661 database in this way:
19665 > create database postgistest;
19666 > \connect postgistest;
19667 > create extension postgis;
19668 > create extension postgis_topology;
19671 There is no need to add this field for contrib extensions such as hstore or
19672 dblink as they are already loadable by postgresql. This field is only
19673 required to add extensions provided by other packages.
19678 @deftp {Data Type} postgresql-config-file
19679 Data type representing the PostgreSQL configuration file. As shown in
19680 the following example, this can be used to customize the configuration
19681 of PostgreSQL@. Note that you can use any G-expression or filename in
19682 place of this record, if you already have a configuration file you'd
19683 like to use for example.
19686 (service postgresql-service-type
19687 (postgresql-configuration
19689 (postgresql-config-file
19690 (log-destination "stderr")
19692 (plain-file "pg_hba.conf"
19694 local all all trust
19695 host all all 127.0.0.1/32 md5
19696 host all all ::1/128 md5"))
19698 '(("session_preload_libraries" "auto_explain")
19699 ("random_page_cost" 2)
19700 ("auto_explain.log_min_duration" "100 ms")
19701 ("work_mem" "500 MB")
19702 ("logging_collector" #t)
19703 ("log_directory" "/var/log/postgresql")))))))
19707 @item @code{log-destination} (default: @code{"syslog"})
19708 The logging method to use for PostgreSQL@. Multiple values are accepted,
19709 separated by commas.
19711 @item @code{hba-file} (default: @code{%default-postgres-hba})
19712 Filename or G-expression for the host-based authentication
19715 @item @code{ident-file} (default: @code{%default-postgres-ident})
19716 Filename or G-expression for the user name mapping configuration.
19718 @item @code{socket-directory} (default: @code{"/var/run/postgresql"})
19719 Specifies the directory of the Unix-domain socket(s) on which PostgreSQL
19720 is to listen for connections from client applications. If set to
19721 @code{#false} PostgreSQL does not listen on any Unix-domain sockets, in
19722 which case only TCP/IP sockets can be used to connect to the server.
19724 @item @code{extra-config} (default: @code{'()})
19725 List of additional keys and values to include in the PostgreSQL config
19726 file. Each entry in the list should be a list where the first element
19727 is the key, and the remaining elements are the values.
19729 The values can be numbers, booleans or strings and will be mapped to
19730 PostgreSQL parameters types @code{Boolean}, @code{String},
19731 @code{Numeric}, @code{Numeric with Unit} and @code{Enumerated} described
19732 @uref{https://www.postgresql.org/docs/current/config-setting.html,
19738 @deffn {Scheme Variable} postgresql-role-service-type
19739 This service allows to create PostgreSQL roles and databases after
19740 PostgreSQL service start. Here is an example of its use.
19743 (service postgresql-role-service-type
19744 (postgresql-role-configuration
19746 (list (postgresql-role
19748 (create-database? #t))))))
19751 This service can be extended with extra roles, as in this
19755 (service-extension postgresql-role-service-type
19756 (const (postgresql-role
19758 (create-database? #t))))
19762 @deftp {Data Type} postgresql-role
19763 PostgreSQL manages database access permissions using the concept of
19764 roles. A role can be thought of as either a database user, or a group
19765 of database users, depending on how the role is set up. Roles can own
19766 database objects (for example, tables) and can assign privileges on
19767 those objects to other roles to control who has access to which objects.
19773 @item @code{permissions} (default: @code{'(createdb login)})
19774 The role permissions list. Supported permissions are @code{bypassrls},
19775 @code{createdb}, @code{createrole}, @code{login}, @code{replication} and
19778 @item @code{create-database?} (default: @code{#f})
19779 Whether to create a database with the same name as the role.
19784 @deftp {Data Type} postgresql-role-configuration
19785 Data type representing the configuration of
19786 @var{postgresql-role-service-type}.
19789 @item @code{host} (default: @code{"/var/run/postgresql"})
19790 The PostgreSQL host to connect to.
19792 @item @code{log} (default: @code{"/var/log/postgresql_roles.log"})
19793 File name of the log file.
19795 @item @code{roles} (default: @code{'()})
19796 The initial PostgreSQL roles to create.
19800 @subsubheading MariaDB/MySQL
19802 @defvr {Scheme Variable} mysql-service-type
19803 This is the service type for a MySQL or MariaDB database server. Its value
19804 is a @code{mysql-configuration} object that specifies which package to use,
19805 as well as various settings for the @command{mysqld} daemon.
19808 @deftp {Data Type} mysql-configuration
19809 Data type representing the configuration of @var{mysql-service-type}.
19812 @item @code{mysql} (default: @var{mariadb})
19813 Package object of the MySQL database server, can be either @var{mariadb}
19816 For MySQL, a temporary root password will be displayed at activation time.
19817 For MariaDB, the root password is empty.
19819 @item @code{bind-address} (default: @code{"127.0.0.1"})
19820 The IP on which to listen for network connections. Use @code{"0.0.0.0"}
19821 to bind to all available network interfaces.
19823 @item @code{port} (default: @code{3306})
19824 TCP port on which the database server listens for incoming connections.
19826 @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
19827 Socket file to use for local (non-network) connections.
19829 @item @code{extra-content} (default: @code{""})
19830 Additional settings for the @file{my.cnf} configuration file.
19832 @item @code{auto-upgrade?} (default: @code{#t})
19833 Whether to automatically run @command{mysql_upgrade} after starting the
19834 service. This is necessary to upgrade the @dfn{system schema} after
19835 ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
19836 be disabled if you would rather do that manually.
19841 @subsubheading Memcached
19843 @defvr {Scheme Variable} memcached-service-type
19844 This is the service type for the @uref{https://memcached.org/,
19845 Memcached} service, which provides a distributed in memory cache. The
19846 value for the service type is a @code{memcached-configuration} object.
19850 (service memcached-service-type)
19853 @deftp {Data Type} memcached-configuration
19854 Data type representing the configuration of memcached.
19857 @item @code{memcached} (default: @code{memcached})
19858 The Memcached package to use.
19860 @item @code{interfaces} (default: @code{'("0.0.0.0")})
19861 Network interfaces on which to listen.
19863 @item @code{tcp-port} (default: @code{11211})
19864 Port on which to accept connections.
19866 @item @code{udp-port} (default: @code{11211})
19867 Port on which to accept UDP connections on, a value of 0 will disable
19868 listening on a UDP socket.
19870 @item @code{additional-options} (default: @code{'()})
19871 Additional command line options to pass to @code{memcached}.
19875 @subsubheading Redis
19877 @defvr {Scheme Variable} redis-service-type
19878 This is the service type for the @uref{https://redis.io/, Redis}
19879 key/value store, whose value is a @code{redis-configuration} object.
19882 @deftp {Data Type} redis-configuration
19883 Data type representing the configuration of redis.
19886 @item @code{redis} (default: @code{redis})
19887 The Redis package to use.
19889 @item @code{bind} (default: @code{"127.0.0.1"})
19890 Network interface on which to listen.
19892 @item @code{port} (default: @code{6379})
19893 Port on which to accept connections on, a value of 0 will disable
19894 listening on a TCP socket.
19896 @item @code{working-directory} (default: @code{"/var/lib/redis"})
19897 Directory in which to store the database and related files.
19901 @node Mail Services
19902 @subsection Mail Services
19906 The @code{(gnu services mail)} module provides Guix service definitions
19907 for email services: IMAP, POP3, and LMTP servers, as well as mail
19908 transport agents (MTAs). Lots of acronyms! These services are detailed
19909 in the subsections below.
19911 @subsubheading Dovecot Service
19913 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
19914 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
19917 By default, Dovecot does not need much configuration; the default
19918 configuration object created by @code{(dovecot-configuration)} will
19919 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
19920 certificate will be generated for TLS-protected connections, though
19921 Dovecot will also listen on cleartext ports by default. There are a
19922 number of options, though, which mail administrators might need to change,
19923 and as is the case with other services, Guix allows the system
19924 administrator to specify these parameters via a uniform Scheme interface.
19926 For example, to specify that mail is located at @code{maildir~/.mail},
19927 one would instantiate the Dovecot service like this:
19930 (dovecot-service #:config
19931 (dovecot-configuration
19932 (mail-location "maildir:~/.mail")))
19935 The available configuration parameters follow. Each parameter
19936 definition is preceded by its type; for example, @samp{string-list foo}
19937 indicates that the @code{foo} parameter should be specified as a list of
19938 strings. There is also a way to specify the configuration as a string,
19939 if you have an old @code{dovecot.conf} file that you want to port over
19940 from some other system; see the end for more details.
19942 @c The following documentation was initially generated by
19943 @c (generate-documentation) in (gnu services mail). Manually maintained
19944 @c documentation is better, so we shouldn't hesitate to edit below as
19945 @c needed. However if the change you want to make to this documentation
19946 @c can be done in an automated way, it's probably easier to change
19947 @c (generate-documentation) than to make it below and have to deal with
19948 @c the churn as dovecot updates.
19950 Available @code{dovecot-configuration} fields are:
19952 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
19953 The dovecot package.
19956 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
19957 A list of IPs or hosts where to listen for connections. @samp{*}
19958 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
19959 interfaces. If you want to specify non-default ports or anything more
19960 complex, customize the address and port fields of the
19961 @samp{inet-listener} of the specific services you are interested in.
19964 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
19965 List of protocols we want to serve. Available protocols include
19966 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
19968 Available @code{protocol-configuration} fields are:
19970 @deftypevr {@code{protocol-configuration} parameter} string name
19971 The name of the protocol.
19974 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
19975 UNIX socket path to the master authentication server to find users.
19976 This is used by imap (for shared users) and lda.
19977 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
19980 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
19981 Space separated list of plugins to load.
19984 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
19985 Maximum number of IMAP connections allowed for a user from each IP
19986 address. NOTE: The username is compared case-sensitively.
19987 Defaults to @samp{10}.
19992 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
19993 List of services to enable. Available services include @samp{imap},
19994 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
19997 Available @code{service-configuration} fields are:
19999 @deftypevr {@code{service-configuration} parameter} string kind
20000 The service kind. Valid values include @code{director},
20001 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
20002 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
20003 @code{tcpwrap}, @code{quota-warning}, or anything else.
20006 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
20007 Listeners for the service. A listener is either a
20008 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
20009 an @code{inet-listener-configuration}.
20010 Defaults to @samp{()}.
20012 Available @code{unix-listener-configuration} fields are:
20014 @deftypevr {@code{unix-listener-configuration} parameter} string path
20015 Path to the file, relative to @code{base-dir} field. This is also used as
20019 @deftypevr {@code{unix-listener-configuration} parameter} string mode
20020 The access mode for the socket.
20021 Defaults to @samp{"0600"}.
20024 @deftypevr {@code{unix-listener-configuration} parameter} string user
20025 The user to own the socket.
20026 Defaults to @samp{""}.
20029 @deftypevr {@code{unix-listener-configuration} parameter} string group
20030 The group to own the socket.
20031 Defaults to @samp{""}.
20035 Available @code{fifo-listener-configuration} fields are:
20037 @deftypevr {@code{fifo-listener-configuration} parameter} string path
20038 Path to the file, relative to @code{base-dir} field. This is also used as
20042 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
20043 The access mode for the socket.
20044 Defaults to @samp{"0600"}.
20047 @deftypevr {@code{fifo-listener-configuration} parameter} string user
20048 The user to own the socket.
20049 Defaults to @samp{""}.
20052 @deftypevr {@code{fifo-listener-configuration} parameter} string group
20053 The group to own the socket.
20054 Defaults to @samp{""}.
20058 Available @code{inet-listener-configuration} fields are:
20060 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
20061 The protocol to listen for.
20064 @deftypevr {@code{inet-listener-configuration} parameter} string address
20065 The address on which to listen, or empty for all addresses.
20066 Defaults to @samp{""}.
20069 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
20070 The port on which to listen.
20073 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
20074 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
20076 Defaults to @samp{#t}.
20081 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
20082 Maximum number of simultaneous client connections per process. Once
20083 this number of connections is received, the next incoming connection
20084 will prompt Dovecot to spawn another process. If set to 0,
20085 @code{default-client-limit} is used instead.
20087 Defaults to @samp{0}.
20091 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
20092 Number of connections to handle before starting a new process.
20093 Typically the only useful values are 0 (unlimited) or 1. 1 is more
20094 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
20095 Defaults to @samp{1}.
20099 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
20100 Maximum number of processes that can exist for this service. If set to
20101 0, @code{default-process-limit} is used instead.
20103 Defaults to @samp{0}.
20107 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
20108 Number of processes to always keep waiting for more connections.
20109 Defaults to @samp{0}.
20112 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
20113 If you set @samp{service-count 0}, you probably need to grow
20115 Defaults to @samp{256000000}.
20120 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
20121 Dict configuration, as created by the @code{dict-configuration}
20124 Available @code{dict-configuration} fields are:
20126 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
20127 A list of key-value pairs that this dict should hold.
20128 Defaults to @samp{()}.
20133 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
20134 A list of passdb configurations, each one created by the
20135 @code{passdb-configuration} constructor.
20137 Available @code{passdb-configuration} fields are:
20139 @deftypevr {@code{passdb-configuration} parameter} string driver
20140 The driver that the passdb should use. Valid values include
20141 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
20143 Defaults to @samp{"pam"}.
20146 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
20147 Space separated list of arguments to the passdb driver.
20148 Defaults to @samp{""}.
20153 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
20154 List of userdb configurations, each one created by the
20155 @code{userdb-configuration} constructor.
20157 Available @code{userdb-configuration} fields are:
20159 @deftypevr {@code{userdb-configuration} parameter} string driver
20160 The driver that the userdb should use. Valid values include
20161 @samp{passwd} and @samp{static}.
20162 Defaults to @samp{"passwd"}.
20165 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
20166 Space separated list of arguments to the userdb driver.
20167 Defaults to @samp{""}.
20170 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
20171 Override fields from passwd.
20172 Defaults to @samp{()}.
20177 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
20178 Plug-in configuration, created by the @code{plugin-configuration}
20182 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
20183 List of namespaces. Each item in the list is created by the
20184 @code{namespace-configuration} constructor.
20186 Available @code{namespace-configuration} fields are:
20188 @deftypevr {@code{namespace-configuration} parameter} string name
20189 Name for this namespace.
20192 @deftypevr {@code{namespace-configuration} parameter} string type
20193 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
20194 Defaults to @samp{"private"}.
20197 @deftypevr {@code{namespace-configuration} parameter} string separator
20198 Hierarchy separator to use. You should use the same separator for
20199 all namespaces or some clients get confused. @samp{/} is usually a good
20200 one. The default however depends on the underlying mail storage
20202 Defaults to @samp{""}.
20205 @deftypevr {@code{namespace-configuration} parameter} string prefix
20206 Prefix required to access this namespace. This needs to be
20207 different for all namespaces. For example @samp{Public/}.
20208 Defaults to @samp{""}.
20211 @deftypevr {@code{namespace-configuration} parameter} string location
20212 Physical location of the mailbox. This is in the same format as
20213 mail_location, which is also the default for it.
20214 Defaults to @samp{""}.
20217 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
20218 There can be only one INBOX, and this setting defines which
20220 Defaults to @samp{#f}.
20223 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
20224 If namespace is hidden, it's not advertised to clients via NAMESPACE
20225 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
20226 useful when converting from another server with different namespaces
20227 which you want to deprecate but still keep working. For example you can
20228 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
20230 Defaults to @samp{#f}.
20233 @deftypevr {@code{namespace-configuration} parameter} boolean list?
20234 Show the mailboxes under this namespace with the LIST command. This
20235 makes the namespace visible for clients that do not support the NAMESPACE
20236 extension. The special @code{children} value lists child mailboxes, but
20237 hides the namespace prefix.
20238 Defaults to @samp{#t}.
20241 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
20242 Namespace handles its own subscriptions. If set to @code{#f}, the
20243 parent namespace handles them. The empty prefix should always have this
20245 Defaults to @samp{#t}.
20248 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
20249 List of predefined mailboxes in this namespace.
20250 Defaults to @samp{()}.
20252 Available @code{mailbox-configuration} fields are:
20254 @deftypevr {@code{mailbox-configuration} parameter} string name
20255 Name for this mailbox.
20258 @deftypevr {@code{mailbox-configuration} parameter} string auto
20259 @samp{create} will automatically create this mailbox.
20260 @samp{subscribe} will both create and subscribe to the mailbox.
20261 Defaults to @samp{"no"}.
20264 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
20265 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
20266 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
20267 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
20268 Defaults to @samp{()}.
20275 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
20276 Base directory where to store runtime data.
20277 Defaults to @samp{"/var/run/dovecot/"}.
20280 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
20281 Greeting message for clients.
20282 Defaults to @samp{"Dovecot ready."}.
20285 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
20286 List of trusted network ranges. Connections from these IPs are
20287 allowed to override their IP addresses and ports (for logging and for
20288 authentication checks). @samp{disable-plaintext-auth} is also ignored
20289 for these networks. Typically you would specify your IMAP proxy servers
20291 Defaults to @samp{()}.
20294 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
20295 List of login access check sockets (e.g.@: tcpwrap).
20296 Defaults to @samp{()}.
20299 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
20300 Show more verbose process titles (in ps). Currently shows user name
20301 and IP address. Useful for seeing who is actually using the IMAP
20302 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
20304 Defaults to @samp{#f}.
20307 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
20308 Should all processes be killed when Dovecot master process shuts down.
20309 Setting this to @code{#f} means that Dovecot can be upgraded without
20310 forcing existing client connections to close (although that could also
20311 be a problem if the upgrade is e.g.@: due to a security fix).
20312 Defaults to @samp{#t}.
20315 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
20316 If non-zero, run mail commands via this many connections to doveadm
20317 server, instead of running them directly in the same process.
20318 Defaults to @samp{0}.
20321 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
20322 UNIX socket or host:port used for connecting to doveadm server.
20323 Defaults to @samp{"doveadm-server"}.
20326 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
20327 List of environment variables that are preserved on Dovecot startup
20328 and passed down to all of its child processes. You can also give
20329 key=value pairs to always set specific settings.
20332 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
20333 Disable LOGIN command and all other plaintext authentications unless
20334 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
20335 matches the local IP (i.e.@: you're connecting from the same computer),
20336 the connection is considered secure and plaintext authentication is
20337 allowed. See also ssl=required setting.
20338 Defaults to @samp{#t}.
20341 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
20342 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
20343 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
20344 for caching to be used.
20345 Defaults to @samp{0}.
20348 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
20349 Time to live for cached data. After TTL expires the cached record
20350 is no longer used, *except* if the main database lookup returns internal
20351 failure. We also try to handle password changes automatically: If
20352 user's previous authentication was successful, but this one wasn't, the
20353 cache isn't used. For now this works only with plaintext
20355 Defaults to @samp{"1 hour"}.
20358 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
20359 TTL for negative hits (user not found, password mismatch).
20360 0 disables caching them completely.
20361 Defaults to @samp{"1 hour"}.
20364 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
20365 List of realms for SASL authentication mechanisms that need them.
20366 You can leave it empty if you don't want to support multiple realms.
20367 Many clients simply use the first one listed here, so keep the default
20369 Defaults to @samp{()}.
20372 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
20373 Default realm/domain to use if none was specified. This is used for
20374 both SASL realms and appending @@domain to username in plaintext
20376 Defaults to @samp{""}.
20379 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
20380 List of allowed characters in username. If the user-given username
20381 contains a character not listed in here, the login automatically fails.
20382 This is just an extra check to make sure user can't exploit any
20383 potential quote escaping vulnerabilities with SQL/LDAP databases. If
20384 you want to allow all characters, set this value to empty.
20385 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
20388 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
20389 Username character translations before it's looked up from
20390 databases. The value contains series of from -> to characters. For
20391 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
20392 translated to @samp{@@}.
20393 Defaults to @samp{""}.
20396 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
20397 Username formatting before it's looked up from databases. You can
20398 use the standard variables here, e.g.@: %Lu would lowercase the username,
20399 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
20400 change the @samp{@@} into @samp{-AT-}. This translation is done after
20401 @samp{auth-username-translation} changes.
20402 Defaults to @samp{"%Lu"}.
20405 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
20406 If you want to allow master users to log in by specifying the master
20407 username within the normal username string (i.e.@: not using SASL
20408 mechanism's support for it), you can specify the separator character
20409 here. The format is then <username><separator><master username>.
20410 UW-IMAP uses @samp{*} as the separator, so that could be a good
20412 Defaults to @samp{""}.
20415 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
20416 Username to use for users logging in with ANONYMOUS SASL
20418 Defaults to @samp{"anonymous"}.
20421 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
20422 Maximum number of dovecot-auth worker processes. They're used to
20423 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
20424 They're automatically created and destroyed as needed.
20425 Defaults to @samp{30}.
20428 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
20429 Host name to use in GSSAPI principal names. The default is to use
20430 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
20431 allow all keytab entries.
20432 Defaults to @samp{""}.
20435 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
20436 Kerberos keytab to use for the GSSAPI mechanism. Will use the
20437 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
20438 need to change the auth service to run as root to be able to read this
20440 Defaults to @samp{""}.
20443 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
20444 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
20445 and @samp{ntlm-auth} helper.
20446 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
20447 Defaults to @samp{#f}.
20450 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
20451 Path for Samba's @samp{ntlm-auth} helper binary.
20452 Defaults to @samp{"/usr/bin/ntlm_auth"}.
20455 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
20456 Time to delay before replying to failed authentications.
20457 Defaults to @samp{"2 secs"}.
20460 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
20461 Require a valid SSL client certificate or the authentication
20463 Defaults to @samp{#f}.
20466 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
20467 Take the username from client's SSL certificate, using
20468 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
20470 Defaults to @samp{#f}.
20473 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
20474 List of wanted authentication mechanisms. Supported mechanisms are:
20475 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
20476 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
20477 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
20478 @samp{disable-plaintext-auth} setting.
20481 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
20482 List of IPs or hostnames to all director servers, including ourself.
20483 Ports can be specified as ip:port. The default port is the same as what
20484 director service's @samp{inet-listener} is using.
20485 Defaults to @samp{()}.
20488 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
20489 List of IPs or hostnames to all backend mail servers. Ranges are
20490 allowed too, like 10.0.0.10-10.0.0.30.
20491 Defaults to @samp{()}.
20494 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
20495 How long to redirect users to a specific server after it no longer
20496 has any connections.
20497 Defaults to @samp{"15 min"}.
20500 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
20501 How the username is translated before being hashed. Useful values
20502 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
20503 are shared within domain.
20504 Defaults to @samp{"%Lu"}.
20507 @deftypevr {@code{dovecot-configuration} parameter} string log-path
20508 Log file to use for error messages. @samp{syslog} logs to syslog,
20509 @samp{/dev/stderr} logs to stderr.
20510 Defaults to @samp{"syslog"}.
20513 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
20514 Log file to use for informational messages. Defaults to
20516 Defaults to @samp{""}.
20519 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
20520 Log file to use for debug messages. Defaults to
20521 @samp{info-log-path}.
20522 Defaults to @samp{""}.
20525 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
20526 Syslog facility to use if you're logging to syslog. Usually if you
20527 don't want to use @samp{mail}, you'll use local0..local7. Also other
20528 standard facilities are supported.
20529 Defaults to @samp{"mail"}.
20532 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
20533 Log unsuccessful authentication attempts and the reasons why they
20535 Defaults to @samp{#f}.
20538 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
20539 In case of password mismatches, log the attempted password. Valid
20540 values are no, plain and sha1. sha1 can be useful for detecting brute
20541 force password attempts vs. user simply trying the same password over
20542 and over again. You can also truncate the value to n chars by appending
20543 ":n" (e.g.@: sha1:6).
20544 Defaults to @samp{"no"}.
20547 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
20548 Even more verbose logging for debugging purposes. Shows for example
20550 Defaults to @samp{#f}.
20553 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
20554 In case of password mismatches, log the passwords and used scheme so
20555 the problem can be debugged. Enabling this also enables
20557 Defaults to @samp{#f}.
20560 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
20561 Enable mail process debugging. This can help you figure out why
20562 Dovecot isn't finding your mails.
20563 Defaults to @samp{#f}.
20566 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
20567 Show protocol level SSL errors.
20568 Defaults to @samp{#f}.
20571 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
20572 Prefix for each line written to log file. % codes are in
20573 strftime(3) format.
20574 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
20577 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
20578 List of elements we want to log. The elements which have a
20579 non-empty variable value are joined together to form a comma-separated
20583 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
20584 Login log format. %s contains @samp{login-log-format-elements}
20585 string, %$ contains the data we want to log.
20586 Defaults to @samp{"%$: %s"}.
20589 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
20590 Log prefix for mail processes. See doc/wiki/Variables.txt for list
20591 of possible variables you can use.
20592 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
20595 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
20596 Format to use for logging mail deliveries. You can use variables:
20599 Delivery status message (e.g.@: @samp{saved to INBOX})
20611 Defaults to @samp{"msgid=%m: %$"}.
20614 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
20615 Location for users' mailboxes. The default is empty, which means
20616 that Dovecot tries to find the mailboxes automatically. This won't work
20617 if the user doesn't yet have any mail, so you should explicitly tell
20618 Dovecot the full location.
20620 If you're using mbox, giving a path to the INBOX
20621 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
20622 where the other mailboxes are kept. This is called the @emph{root mail
20623 directory}, and it must be the first path given in the
20624 @samp{mail-location} setting.
20626 There are a few special variables you can use, e.g.:
20632 user part in user@@domain, same as %u if there's no domain
20634 domain part in user@@domain, empty if there's no domain
20639 See doc/wiki/Variables.txt for full list. Some examples:
20641 @item maildir:~/Maildir
20642 @item mbox:~/mail:INBOX=/var/mail/%u
20643 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
20645 Defaults to @samp{""}.
20648 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
20649 System user and group used to access mails. If you use multiple,
20650 userdb can override these by returning uid or gid fields. You can use
20651 either numbers or names. <doc/wiki/UserIds.txt>.
20652 Defaults to @samp{""}.
20655 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
20657 Defaults to @samp{""}.
20660 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
20661 Group to enable temporarily for privileged operations. Currently
20662 this is used only with INBOX when either its initial creation or
20663 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
20665 Defaults to @samp{""}.
20668 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
20669 Grant access to these supplementary groups for mail processes.
20670 Typically these are used to set up access to shared mailboxes. Note
20671 that it may be dangerous to set these if users can create symlinks
20672 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
20673 could allow a user to delete others' mailboxes, or @code{ln -s
20674 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
20678 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
20679 Allow full file system access to clients. There's no access checks
20680 other than what the operating system does for the active UID/GID@. It
20681 works with both maildir and mboxes, allowing you to prefix mailboxes
20682 names with e.g.@: @file{/path/} or @file{~user/}.
20683 Defaults to @samp{#f}.
20686 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
20687 Don't use @code{mmap()} at all. This is required if you store indexes to
20688 shared file systems (NFS or clustered file system).
20689 Defaults to @samp{#f}.
20692 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
20693 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
20694 supports @samp{O_EXCL} since version 3, so this should be safe to use
20695 nowadays by default.
20696 Defaults to @samp{#t}.
20699 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
20700 When to use fsync() or fdatasync() calls:
20703 Whenever necessary to avoid losing important data
20705 Useful with e.g.@: NFS when @code{write()}s are delayed
20707 Never use it (best performance, but crashes can lose data).
20709 Defaults to @samp{"optimized"}.
20712 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
20713 Mail storage exists in NFS@. Set this to yes to make Dovecot flush
20714 NFS caches whenever needed. If you're using only a single mail server
20716 Defaults to @samp{#f}.
20719 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
20720 Mail index files also exist in NFS@. Setting this to yes requires
20721 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
20722 Defaults to @samp{#f}.
20725 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
20726 Locking method for index files. Alternatives are fcntl, flock and
20727 dotlock. Dotlocking uses some tricks which may create more disk I/O
20728 than other locking methods. NFS users: flock doesn't work, remember to
20729 change @samp{mmap-disable}.
20730 Defaults to @samp{"fcntl"}.
20733 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
20734 Directory in which LDA/LMTP temporarily stores incoming mails >128
20736 Defaults to @samp{"/tmp"}.
20739 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
20740 Valid UID range for users. This is mostly to make sure that users can't
20741 log in as daemons or other system users. Note that denying root logins is
20742 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
20744 Defaults to @samp{500}.
20747 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
20749 Defaults to @samp{0}.
20752 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
20753 Valid GID range for users. Users having non-valid GID as primary group ID
20754 aren't allowed to log in. If user belongs to supplementary groups with
20755 non-valid GIDs, those groups are not set.
20756 Defaults to @samp{1}.
20759 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
20761 Defaults to @samp{0}.
20764 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
20765 Maximum allowed length for mail keyword name. It's only forced when
20766 trying to create new keywords.
20767 Defaults to @samp{50}.
20770 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
20771 List of directories under which chrooting is allowed for mail
20772 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
20773 too). This setting doesn't affect @samp{login-chroot}
20774 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
20775 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
20776 which local users can modify, that may lead to root exploit. Usually
20777 this should be done only if you don't allow shell access for users.
20778 <doc/wiki/Chrooting.txt>.
20779 Defaults to @samp{()}.
20782 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
20783 Default chroot directory for mail processes. This can be overridden
20784 for specific users in user database by giving @samp{/./} in user's home
20785 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
20786 there is no real need to do chrooting, Dovecot doesn't allow users to
20787 access files outside their mail directory anyway. If your home
20788 directories are prefixed with the chroot directory, append @samp{/.} to
20789 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
20790 Defaults to @samp{""}.
20793 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
20794 UNIX socket path to master authentication server to find users.
20795 This is used by imap (for shared users) and lda.
20796 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
20799 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
20800 Directory where to look up mail plugins.
20801 Defaults to @samp{"/usr/lib/dovecot"}.
20804 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
20805 List of plugins to load for all services. Plugins specific to IMAP,
20806 LDA, etc.@: are added to this list in their own .conf files.
20807 Defaults to @samp{()}.
20810 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
20811 The minimum number of mails in a mailbox before updates are done to
20812 cache file. This allows optimizing Dovecot's behavior to do less disk
20813 writes at the cost of more disk reads.
20814 Defaults to @samp{0}.
20817 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
20818 When IDLE command is running, mailbox is checked once in a while to
20819 see if there are any new mails or other changes. This setting defines
20820 the minimum time to wait between those checks. Dovecot can also use
20821 dnotify, inotify and kqueue to find out immediately when changes
20823 Defaults to @samp{"30 secs"}.
20826 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
20827 Save mails with CR+LF instead of plain LF@. This makes sending those
20828 mails take less CPU, especially with sendfile() syscall with Linux and
20829 FreeBSD@. But it also creates a bit more disk I/O which may just make it
20830 slower. Also note that if other software reads the mboxes/maildirs,
20831 they may handle the extra CRs wrong and cause problems.
20832 Defaults to @samp{#f}.
20835 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
20836 By default LIST command returns all entries in maildir beginning
20837 with a dot. Enabling this option makes Dovecot return only entries
20838 which are directories. This is done by stat()ing each entry, so it
20839 causes more disk I/O.
20840 (For systems setting struct @samp{dirent->d_type} this check is free
20841 and it's done always regardless of this setting).
20842 Defaults to @samp{#f}.
20845 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
20846 When copying a message, do it with hard links whenever possible.
20847 This makes the performance much better, and it's unlikely to have any
20849 Defaults to @samp{#t}.
20852 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
20853 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
20854 directory only when its mtime changes unexpectedly or when we can't find
20855 the mail otherwise.
20856 Defaults to @samp{#f}.
20859 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
20860 Which locking methods to use for locking mbox. There are four
20865 Create <mailbox>.lock file. This is the oldest and most NFS-safe
20866 solution. If you want to use /var/mail/ like directory, the users will
20867 need write access to that directory.
20869 Same as dotlock, but if it fails because of permissions or because there
20870 isn't enough disk space, just skip it.
20872 Use this if possible. Works with NFS too if lockd is used.
20874 May not exist in all systems. Doesn't work with NFS.
20876 May not exist in all systems. Doesn't work with NFS.
20879 You can use multiple locking methods; if you do the order they're declared
20880 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
20881 locking methods as well. Some operating systems don't allow using some of
20882 them simultaneously.
20885 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
20889 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
20890 Maximum time to wait for lock (all of them) before aborting.
20891 Defaults to @samp{"5 mins"}.
20894 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
20895 If dotlock exists but the mailbox isn't modified in any way,
20896 override the lock file after this much time.
20897 Defaults to @samp{"2 mins"}.
20900 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
20901 When mbox changes unexpectedly we have to fully read it to find out
20902 what changed. If the mbox is large this can take a long time. Since
20903 the change is usually just a newly appended mail, it'd be faster to
20904 simply read the new mails. If this setting is enabled, Dovecot does
20905 this but still safely fallbacks to re-reading the whole mbox file
20906 whenever something in mbox isn't how it's expected to be. The only real
20907 downside to this setting is that if some other MUA changes message
20908 flags, Dovecot doesn't notice it immediately. Note that a full sync is
20909 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
20910 Defaults to @samp{#t}.
20913 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
20914 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
20915 EXAMINE, EXPUNGE or CHECK commands. If this is set,
20916 @samp{mbox-dirty-syncs} is ignored.
20917 Defaults to @samp{#f}.
20920 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
20921 Delay writing mbox headers until doing a full write sync (EXPUNGE
20922 and CHECK commands and when closing the mailbox). This is especially
20923 useful for POP3 where clients often delete all mails. The downside is
20924 that our changes aren't immediately visible to other MUAs.
20925 Defaults to @samp{#t}.
20928 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
20929 If mbox size is smaller than this (e.g.@: 100k), don't write index
20930 files. If an index file already exists it's still read, just not
20932 Defaults to @samp{0}.
20935 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
20936 Maximum dbox file size until it's rotated.
20937 Defaults to @samp{10000000}.
20940 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
20941 Maximum dbox file age until it's rotated. Typically in days. Day
20942 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
20944 Defaults to @samp{"1d"}.
20947 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
20948 When creating new mdbox files, immediately preallocate their size to
20949 @samp{mdbox-rotate-size}. This setting currently works only in Linux
20950 with some file systems (ext4, xfs).
20951 Defaults to @samp{#f}.
20954 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
20955 sdbox and mdbox support saving mail attachments to external files,
20956 which also allows single instance storage for them. Other backends
20957 don't support this for now.
20959 WARNING: This feature hasn't been tested much yet. Use at your own risk.
20961 Directory root where to store mail attachments. Disabled, if empty.
20962 Defaults to @samp{""}.
20965 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
20966 Attachments smaller than this aren't saved externally. It's also
20967 possible to write a plugin to disable saving specific attachments
20969 Defaults to @samp{128000}.
20972 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
20973 File system backend to use for saving attachments:
20976 No SiS done by Dovecot (but this might help FS's own deduplication)
20978 SiS with immediate byte-by-byte comparison during saving
20979 @item sis-queue posix
20980 SiS with delayed comparison and deduplication.
20982 Defaults to @samp{"sis posix"}.
20985 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
20986 Hash format to use in attachment filenames. You can add any text and
20987 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
20988 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
20989 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
20990 Defaults to @samp{"%@{sha1@}"}.
20993 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
20995 Defaults to @samp{100}.
20998 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
21000 Defaults to @samp{1000}.
21003 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
21004 Default VSZ (virtual memory size) limit for service processes.
21005 This is mainly intended to catch and kill processes that leak memory
21006 before they eat up everything.
21007 Defaults to @samp{256000000}.
21010 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
21011 Login user is internally used by login processes. This is the most
21012 untrusted user in Dovecot system. It shouldn't have access to anything
21014 Defaults to @samp{"dovenull"}.
21017 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
21018 Internal user is used by unprivileged processes. It should be
21019 separate from login user, so that login processes can't disturb other
21021 Defaults to @samp{"dovecot"}.
21024 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
21025 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
21026 Defaults to @samp{"required"}.
21029 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
21030 PEM encoded X.509 SSL/TLS certificate (public key).
21031 Defaults to @samp{"</etc/dovecot/default.pem"}.
21034 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
21035 PEM encoded SSL/TLS private key. The key is opened before
21036 dropping root privileges, so keep the key file unreadable by anyone but
21038 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
21041 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
21042 If key file is password protected, give the password here.
21043 Alternatively give it when starting dovecot with -p parameter. Since
21044 this file is often world-readable, you may want to place this setting
21045 instead to a different.
21046 Defaults to @samp{""}.
21049 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
21050 PEM encoded trusted certificate authority. Set this only if you
21051 intend to use @samp{ssl-verify-client-cert? #t}. The file should
21052 contain the CA certificate(s) followed by the matching
21053 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
21054 Defaults to @samp{""}.
21057 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
21058 Require that CRL check succeeds for client certificates.
21059 Defaults to @samp{#t}.
21062 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
21063 Request client to send a certificate. If you also want to require
21064 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
21065 Defaults to @samp{#f}.
21068 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
21069 Which field from certificate to use for username. commonName and
21070 x500UniqueIdentifier are the usual choices. You'll also need to set
21071 @samp{auth-ssl-username-from-cert? #t}.
21072 Defaults to @samp{"commonName"}.
21075 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
21076 Minimum SSL protocol version to accept.
21077 Defaults to @samp{"TLSv1"}.
21080 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
21081 SSL ciphers to use.
21082 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
21085 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
21086 SSL crypto device to use, for valid values run "openssl engine".
21087 Defaults to @samp{""}.
21090 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
21091 Address to use when sending rejection mails.
21092 %d expands to recipient domain.
21093 Defaults to @samp{"postmaster@@%d"}.
21096 @deftypevr {@code{dovecot-configuration} parameter} string hostname
21097 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
21098 and in LMTP replies. Default is the system's real hostname@@domain.
21099 Defaults to @samp{""}.
21102 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
21103 If user is over quota, return with temporary failure instead of
21105 Defaults to @samp{#f}.
21108 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
21109 Binary to use for sending mails.
21110 Defaults to @samp{"/usr/sbin/sendmail"}.
21113 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
21114 If non-empty, send mails via this SMTP host[:port] instead of
21116 Defaults to @samp{""}.
21119 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
21120 Subject: header to use for rejection mails. You can use the same
21121 variables as for @samp{rejection-reason} below.
21122 Defaults to @samp{"Rejected: %s"}.
21125 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
21126 Human readable error message for rejection mails. You can use
21139 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
21142 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
21143 Delimiter character between local-part and detail in email
21145 Defaults to @samp{"+"}.
21148 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
21149 Header where the original recipient address (SMTP's RCPT TO:
21150 address) is taken from if not available elsewhere. With dovecot-lda -a
21151 parameter overrides this. A commonly used header for this is
21153 Defaults to @samp{""}.
21156 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
21157 Should saving a mail to a nonexistent mailbox automatically create
21159 Defaults to @samp{#f}.
21162 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
21163 Should automatically created mailboxes be also automatically
21165 Defaults to @samp{#f}.
21168 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
21169 Maximum IMAP command line length. Some clients generate very long
21170 command lines with huge mailboxes, so you may need to raise this if you
21171 get "Too long argument" or "IMAP command line too large" errors
21173 Defaults to @samp{64000}.
21176 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
21177 IMAP logout format string:
21180 total number of bytes read from client
21182 total number of bytes sent to client.
21184 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
21185 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@}"}.
21188 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
21189 Override the IMAP CAPABILITY response. If the value begins with '+',
21190 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
21191 Defaults to @samp{""}.
21194 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
21195 How long to wait between "OK Still here" notifications when client
21197 Defaults to @samp{"2 mins"}.
21200 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
21201 ID field names and values to send to clients. Using * as the value
21202 makes Dovecot use the default value. The following fields have default
21203 values currently: name, version, os, os-version, support-url,
21205 Defaults to @samp{""}.
21208 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
21209 ID fields sent by client to log. * means everything.
21210 Defaults to @samp{""}.
21213 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
21214 Workarounds for various client bugs:
21217 @item delay-newmail
21218 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
21219 CHECK commands. Some clients ignore them otherwise, for example OSX
21220 Mail (<v2.1). Outlook Express breaks more badly though, without this it
21221 may show user "Message no longer in server" errors. Note that OE6
21222 still breaks even with this workaround if synchronization is set to
21225 @item tb-extra-mailbox-sep
21226 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
21227 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
21228 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
21230 @item tb-lsub-flags
21231 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
21232 This makes Thunderbird realize they aren't selectable and show them
21233 greyed out, instead of only later giving "not selectable" popup error.
21235 Defaults to @samp{()}.
21238 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
21239 Host allowed in URLAUTH URLs sent by client. "*" allows all.
21240 Defaults to @samp{""}.
21244 Whew! Lots of configuration options. The nice thing about it though is
21245 that Guix has a complete interface to Dovecot's configuration
21246 language. This allows not only a nice way to declare configurations,
21247 but also offers reflective capabilities as well: users can write code to
21248 inspect and transform configurations from within Scheme.
21250 However, it could be that you just want to get a @code{dovecot.conf} up
21251 and running. In that case, you can pass an
21252 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
21253 @code{dovecot-service}. As its name indicates, an opaque configuration
21254 does not have easy reflective capabilities.
21256 Available @code{opaque-dovecot-configuration} fields are:
21258 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
21259 The dovecot package.
21262 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
21263 The contents of the @code{dovecot.conf}, as a string.
21266 For example, if your @code{dovecot.conf} is just the empty string, you
21267 could instantiate a dovecot service like this:
21270 (dovecot-service #:config
21271 (opaque-dovecot-configuration
21275 @subsubheading OpenSMTPD Service
21277 @deffn {Scheme Variable} opensmtpd-service-type
21278 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
21279 service, whose value should be an @code{opensmtpd-configuration} object
21280 as in this example:
21283 (service opensmtpd-service-type
21284 (opensmtpd-configuration
21285 (config-file (local-file "./my-smtpd.conf"))))
21289 @deftp {Data Type} opensmtpd-configuration
21290 Data type representing the configuration of opensmtpd.
21293 @item @code{package} (default: @var{opensmtpd})
21294 Package object of the OpenSMTPD SMTP server.
21296 @item @code{config-file} (default: @code{%default-opensmtpd-file})
21297 File-like object of the OpenSMTPD configuration file to use. By default
21298 it listens on the loopback network interface, and allows for mail from
21299 users and daemons on the local machine, as well as permitting email to
21300 remote servers. Run @command{man smtpd.conf} for more information.
21305 @subsubheading Exim Service
21307 @cindex mail transfer agent (MTA)
21308 @cindex MTA (mail transfer agent)
21311 @deffn {Scheme Variable} exim-service-type
21312 This is the type of the @uref{https://exim.org, Exim} mail transfer
21313 agent (MTA), whose value should be an @code{exim-configuration} object
21314 as in this example:
21317 (service exim-service-type
21318 (exim-configuration
21319 (config-file (local-file "./my-exim.conf"))))
21323 In order to use an @code{exim-service-type} service you must also have a
21324 @code{mail-aliases-service-type} service present in your
21325 @code{operating-system} (even if it has no aliases).
21327 @deftp {Data Type} exim-configuration
21328 Data type representing the configuration of exim.
21331 @item @code{package} (default: @var{exim})
21332 Package object of the Exim server.
21334 @item @code{config-file} (default: @code{#f})
21335 File-like object of the Exim configuration file to use. If its value is
21336 @code{#f} then use the default configuration file from the package
21337 provided in @code{package}. The resulting configuration file is loaded
21338 after setting the @code{exim_user} and @code{exim_group} configuration
21344 @subsubheading Getmail service
21349 @deffn {Scheme Variable} getmail-service-type
21350 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
21351 mail retriever, whose value should be an @code{getmail-configuration}.
21354 Available @code{getmail-configuration} fields are:
21356 @deftypevr {@code{getmail-configuration} parameter} symbol name
21357 A symbol to identify the getmail service.
21359 Defaults to @samp{"unset"}.
21363 @deftypevr {@code{getmail-configuration} parameter} package package
21364 The getmail package to use.
21368 @deftypevr {@code{getmail-configuration} parameter} string user
21369 The user to run getmail as.
21371 Defaults to @samp{"getmail"}.
21375 @deftypevr {@code{getmail-configuration} parameter} string group
21376 The group to run getmail as.
21378 Defaults to @samp{"getmail"}.
21382 @deftypevr {@code{getmail-configuration} parameter} string directory
21383 The getmail directory to use.
21385 Defaults to @samp{"/var/lib/getmail/default"}.
21389 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
21390 The getmail configuration file to use.
21392 Available @code{getmail-configuration-file} fields are:
21394 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
21395 What mail account to retrieve mail from, and how to access that account.
21397 Available @code{getmail-retriever-configuration} fields are:
21399 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
21400 The type of mail retriever to use. Valid values include @samp{passwd}
21403 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
21407 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
21408 Username to login to the mail server with.
21410 Defaults to @samp{unset}.
21414 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
21415 Username to login to the mail server with.
21417 Defaults to @samp{unset}.
21421 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
21422 Port number to connect to.
21424 Defaults to @samp{#f}.
21428 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
21429 Override fields from passwd.
21431 Defaults to @samp{""}.
21435 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
21436 Override fields from passwd.
21438 Defaults to @samp{()}.
21442 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
21443 PEM-formatted key file to use for the TLS negotiation.
21445 Defaults to @samp{""}.
21449 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
21450 PEM-formatted certificate file to use for the TLS negotiation.
21452 Defaults to @samp{""}.
21456 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
21457 CA certificates to use.
21459 Defaults to @samp{""}.
21463 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
21464 Extra retriever parameters.
21466 Defaults to @samp{()}.
21472 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
21473 What to do with retrieved messages.
21475 Available @code{getmail-destination-configuration} fields are:
21477 @deftypevr {@code{getmail-destination-configuration} parameter} string type
21478 The type of mail destination. Valid values include @samp{Maildir},
21479 @samp{Mboxrd} and @samp{MDA_external}.
21481 Defaults to @samp{unset}.
21485 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
21486 The path option for the mail destination. The behaviour depends on the
21489 Defaults to @samp{""}.
21493 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
21494 Extra destination parameters
21496 Defaults to @samp{()}.
21502 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
21505 Available @code{getmail-options-configuration} fields are:
21507 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
21508 If set to @samp{0}, getmail will only print warnings and errors. A
21509 value of @samp{1} means that messages will be printed about retrieving
21510 and deleting messages. If set to @samp{2}, getmail will print messages
21511 about each of it's actions.
21513 Defaults to @samp{1}.
21517 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
21518 If true, getmail will retrieve all available messages. Otherwise it
21519 will only retrieve messages it hasn't seen previously.
21521 Defaults to @samp{#t}.
21525 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
21526 If set to true, messages will be deleted from the server after
21527 retrieving and successfully delivering them. Otherwise, messages will
21528 be left on the server.
21530 Defaults to @samp{#f}.
21534 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
21535 Getmail will delete messages this number of days after seeing them, if
21536 they have been delivered. This means messages will be left on the
21537 server this number of days after delivering them. A value of @samp{0}
21538 disabled this feature.
21540 Defaults to @samp{0}.
21544 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
21545 Delete messages larger than this of bytes after retrieving them, even if
21546 the delete and delete-after options are disabled. A value of @samp{0}
21547 disables this feature.
21549 Defaults to @samp{0}.
21553 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
21554 Retrieve messages totalling up to this number of bytes before closing
21555 the session with the server. A value of @samp{0} disables this feature.
21557 Defaults to @samp{0}.
21561 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
21562 Don't retrieve messages larger than this number of bytes. A value of
21563 @samp{0} disables this feature.
21565 Defaults to @samp{0}.
21569 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
21570 If true, getmail will add a Delivered-To header to messages.
21572 Defaults to @samp{#t}.
21576 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
21577 If set, getmail adds a Received header to the messages.
21579 Defaults to @samp{#t}.
21583 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
21584 Getmail will record a log of its actions to the named file. A value of
21585 @samp{""} disables this feature.
21587 Defaults to @samp{""}.
21591 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
21592 If true, getmail will record a log of its actions using the system
21595 Defaults to @samp{#f}.
21599 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
21600 If true, getmail will log information about messages not retrieved and
21601 the reason for not retrieving them, as well as starting and ending
21604 Defaults to @samp{#f}.
21608 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
21609 Extra options to include.
21611 Defaults to @samp{()}.
21619 @deftypevr {@code{getmail-configuration} parameter} list idle
21620 A list of mailboxes that getmail should wait on the server for new mail
21621 notifications. This depends on the server supporting the IDLE
21624 Defaults to @samp{()}.
21628 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
21629 Environment variables to set for getmail.
21631 Defaults to @samp{()}.
21635 @subsubheading Mail Aliases Service
21637 @cindex email aliases
21638 @cindex aliases, for email addresses
21640 @deffn {Scheme Variable} mail-aliases-service-type
21641 This is the type of the service which provides @code{/etc/aliases},
21642 specifying how to deliver mail to users on this system.
21645 (service mail-aliases-service-type
21646 '(("postmaster" "bob")
21647 ("bob" "bob@@example.com" "bob@@example2.com")))
21651 The configuration for a @code{mail-aliases-service-type} service is an
21652 association list denoting how to deliver mail that comes to this
21653 system. Each entry is of the form @code{(alias addresses ...)}, with
21654 @code{alias} specifying the local alias and @code{addresses} specifying
21655 where to deliver this user's mail.
21657 The aliases aren't required to exist as users on the local system. In
21658 the above example, there doesn't need to be a @code{postmaster} entry in
21659 the @code{operating-system}'s @code{user-accounts} in order to deliver
21660 the @code{postmaster} mail to @code{bob} (which subsequently would
21661 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
21663 @subsubheading GNU Mailutils IMAP4 Daemon
21664 @cindex GNU Mailutils IMAP4 Daemon
21666 @deffn {Scheme Variable} imap4d-service-type
21667 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
21668 mailutils, GNU Mailutils Manual}), whose value should be an
21669 @code{imap4d-configuration} object as in this example:
21672 (service imap4d-service-type
21673 (imap4d-configuration
21674 (config-file (local-file "imap4d.conf"))))
21678 @deftp {Data Type} imap4d-configuration
21679 Data type representing the configuration of @command{imap4d}.
21682 @item @code{package} (default: @code{mailutils})
21683 The package that provides @command{imap4d}.
21685 @item @code{config-file} (default: @code{%default-imap4d-config-file})
21686 File-like object of the configuration file to use, by default it will listen
21687 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
21688 Mailutils Manual}, for details.
21693 @subsubheading Radicale Service
21697 @deffn {Scheme Variable} radicale-service-type
21698 This is the type of the @uref{https://radicale.org, Radicale} CalDAV/CardDAV
21699 server whose value should be a @code{radicale-configuration}.
21702 @deftp {Data Type} radicale-configuration
21703 Data type representing the configuration of @command{radicale}.
21706 @item @code{package} (default: @code{radicale})
21707 The package that provides @command{radicale}.
21709 @item @code{config-file} (default: @code{%default-radicale-config-file})
21710 File-like object of the configuration file to use, by default it will listen
21711 on TCP port 5232 of @code{localhost} and use the @code{htpasswd} file at
21712 @file{/var/lib/radicale/users} with no (@code{plain}) encryption.
21717 @node Messaging Services
21718 @subsection Messaging Services
21723 The @code{(gnu services messaging)} module provides Guix service
21724 definitions for messaging services. Currently it provides the following
21727 @subsubheading Prosody Service
21729 @deffn {Scheme Variable} prosody-service-type
21730 This is the type for the @uref{https://prosody.im, Prosody XMPP
21731 communication server}. Its value must be a @code{prosody-configuration}
21732 record as in this example:
21735 (service prosody-service-type
21736 (prosody-configuration
21737 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
21740 (int-component-configuration
21741 (hostname "conference.example.net")
21743 (mod-muc (mod-muc-configuration)))))
21746 (virtualhost-configuration
21747 (domain "example.net"))))))
21750 See below for details about @code{prosody-configuration}.
21754 By default, Prosody does not need much configuration. Only one
21755 @code{virtualhosts} field is needed: it specifies the domain you wish
21758 You can perform various sanity checks on the generated configuration
21759 with the @code{prosodyctl check} command.
21761 Prosodyctl will also help you to import certificates from the
21762 @code{letsencrypt} directory so that the @code{prosody} user can access
21763 them. See @url{https://prosody.im/doc/letsencrypt}.
21766 prosodyctl --root cert import /etc/letsencrypt/live
21769 The available configuration parameters follow. Each parameter
21770 definition is preceded by its type; for example, @samp{string-list foo}
21771 indicates that the @code{foo} parameter should be specified as a list of
21772 strings. Types starting with @code{maybe-} denote parameters that won't
21773 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
21775 There is also a way to specify the configuration as a string, if you
21776 have an old @code{prosody.cfg.lua} file that you want to port over from
21777 some other system; see the end for more details.
21779 The @code{file-object} type designates either a file-like object
21780 (@pxref{G-Expressions, file-like objects}) or a file name.
21782 @c The following documentation was initially generated by
21783 @c (generate-documentation) in (gnu services messaging). Manually maintained
21784 @c documentation is better, so we shouldn't hesitate to edit below as
21785 @c needed. However if the change you want to make to this documentation
21786 @c can be done in an automated way, it's probably easier to change
21787 @c (generate-documentation) than to make it below and have to deal with
21788 @c the churn as Prosody updates.
21790 Available @code{prosody-configuration} fields are:
21792 @deftypevr {@code{prosody-configuration} parameter} package prosody
21793 The Prosody package.
21796 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
21797 Location of the Prosody data storage directory. See
21798 @url{https://prosody.im/doc/configure}.
21799 Defaults to @samp{"/var/lib/prosody"}.
21802 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
21803 Additional plugin directories. They are searched in all the specified
21804 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
21805 Defaults to @samp{()}.
21808 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
21809 Every virtual host and component needs a certificate so that clients and
21810 servers can securely verify its identity. Prosody will automatically load
21811 certificates/keys from the directory specified here.
21812 Defaults to @samp{"/etc/prosody/certs"}.
21815 @deftypevr {@code{prosody-configuration} parameter} string-list admins
21816 This is a list of accounts that are admins for the server. Note that you
21817 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
21818 @url{https://prosody.im/doc/creating_accounts}.
21819 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
21820 Defaults to @samp{()}.
21823 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
21824 Enable use of libevent for better performance under high load. See
21825 @url{https://prosody.im/doc/libevent}.
21826 Defaults to @samp{#f}.
21829 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
21830 This is the list of modules Prosody will load on startup. It looks for
21831 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
21832 Documentation on modules can be found at:
21833 @url{https://prosody.im/doc/modules}.
21834 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
21837 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
21838 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
21839 should you want to disable them then add them to this list.
21840 Defaults to @samp{()}.
21843 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
21844 Path to a text file where the shared groups are defined. If this path is
21845 empty then @samp{mod_groups} does nothing. See
21846 @url{https://prosody.im/doc/modules/mod_groups}.
21847 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
21850 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
21851 Disable account creation by default, for security. See
21852 @url{https://prosody.im/doc/creating_accounts}.
21853 Defaults to @samp{#f}.
21856 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
21857 These are the SSL/TLS-related settings. Most of them are disabled so to
21858 use Prosody's defaults. If you do not completely understand these options, do
21859 not add them to your config, it is easy to lower the security of your server
21860 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
21862 Available @code{ssl-configuration} fields are:
21864 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
21865 This determines what handshake to use.
21868 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
21869 Path to your private key file.
21872 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
21873 Path to your certificate file.
21876 @deftypevr {@code{ssl-configuration} parameter} file-object capath
21877 Path to directory containing root certificates that you wish Prosody to
21878 trust when verifying the certificates of remote servers.
21879 Defaults to @samp{"/etc/ssl/certs"}.
21882 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
21883 Path to a file containing root certificates that you wish Prosody to trust.
21884 Similar to @code{capath} but with all certificates concatenated together.
21887 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
21888 A list of verification options (these mostly map to OpenSSL's
21889 @code{set_verify()} flags).
21892 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
21893 A list of general options relating to SSL/TLS@. These map to OpenSSL's
21894 @code{set_options()}. For a full list of options available in LuaSec, see the
21898 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
21899 How long a chain of certificate authorities to check when looking for a
21900 trusted root certificate.
21903 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
21904 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
21905 clients, and in what order.
21908 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
21909 A path to a file containing parameters for Diffie-Hellman key exchange. You
21910 can create such a file with:
21911 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
21914 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
21915 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
21916 @samp{"secp384r1"}.
21919 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
21920 A list of ``extra'' verification options.
21923 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
21924 Password for encrypted private keys.
21929 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
21930 Whether to force all client-to-server connections to be encrypted or not.
21931 See @url{https://prosody.im/doc/modules/mod_tls}.
21932 Defaults to @samp{#f}.
21935 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
21936 Set of mechanisms that will never be offered. See
21937 @url{https://prosody.im/doc/modules/mod_saslauth}.
21938 Defaults to @samp{("DIGEST-MD5")}.
21941 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
21942 Whether to force all server-to-server connections to be encrypted or not.
21943 See @url{https://prosody.im/doc/modules/mod_tls}.
21944 Defaults to @samp{#f}.
21947 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
21948 Whether to require encryption and certificate authentication. This
21949 provides ideal security, but requires servers you communicate with to support
21950 encryption AND present valid, trusted certificates. See
21951 @url{https://prosody.im/doc/s2s#security}.
21952 Defaults to @samp{#f}.
21955 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
21956 Many servers don't support encryption or have invalid or self-signed
21957 certificates. You can list domains here that will not be required to
21958 authenticate using certificates. They will be authenticated using DNS@. See
21959 @url{https://prosody.im/doc/s2s#security}.
21960 Defaults to @samp{()}.
21963 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
21964 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
21965 valid certificates for some domains by specifying a list here. See
21966 @url{https://prosody.im/doc/s2s#security}.
21967 Defaults to @samp{()}.
21970 @deftypevr {@code{prosody-configuration} parameter} string authentication
21971 Select the authentication backend to use. The default provider stores
21972 passwords in plaintext and uses Prosody's configured data storage to store the
21973 authentication data. If you do not trust your server please see
21974 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
21975 about using the hashed backend. See also
21976 @url{https://prosody.im/doc/authentication}
21977 Defaults to @samp{"internal_plain"}.
21980 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
21981 Set logging options. Advanced logging configuration is not yet supported
21982 by the Prosody service. See @url{https://prosody.im/doc/logging}.
21983 Defaults to @samp{"*syslog"}.
21986 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
21987 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
21988 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
21991 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
21992 Maximum allowed size of the HTTP body (in bytes).
21995 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
21996 Some modules expose their own URL in various ways. This URL is built
21997 from the protocol, host and port used. If Prosody sits behind a proxy, the
21998 public URL will be @code{http-external-url} instead. See
21999 @url{https://prosody.im/doc/http#external_url}.
22002 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
22003 A host in Prosody is a domain on which user accounts can be created. For
22004 example if you want your users to have addresses like
22005 @samp{"john.smith@@example.com"} then you need to add a host
22006 @samp{"example.com"}. All options in this list will apply only to this host.
22008 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
22009 the actual physical host that Prosody is installed on. A single Prosody
22010 instance can serve many domains, each one defined as a VirtualHost entry in
22011 Prosody's configuration. Conversely a server that hosts a single domain would
22012 have just one VirtualHost entry.
22014 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
22016 Available @code{virtualhost-configuration} fields are:
22018 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:
22019 @deftypevr {@code{virtualhost-configuration} parameter} string domain
22020 Domain you wish Prosody to serve.
22025 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
22026 Components are extra services on a server which are available to clients,
22027 usually on a subdomain of the main server (such as
22028 @samp{"mycomponent.example.com"}). Example components might be chatroom
22029 servers, user directories, or gateways to other protocols.
22031 Internal components are implemented with Prosody-specific plugins. To add an
22032 internal component, you simply fill the hostname field, and the plugin you wish
22033 to use for the component.
22035 See @url{https://prosody.im/doc/components}.
22036 Defaults to @samp{()}.
22038 Available @code{int-component-configuration} fields are:
22040 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:
22041 @deftypevr {@code{int-component-configuration} parameter} string hostname
22042 Hostname of the component.
22045 @deftypevr {@code{int-component-configuration} parameter} string plugin
22046 Plugin you wish to use for the component.
22049 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
22050 Multi-user chat (MUC) is Prosody's module for allowing you to create
22051 hosted chatrooms/conferences for XMPP users.
22053 General information on setting up and using multi-user chatrooms can be found
22054 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
22055 which you should read if you are new to XMPP chatrooms.
22057 See also @url{https://prosody.im/doc/modules/mod_muc}.
22059 Available @code{mod-muc-configuration} fields are:
22061 @deftypevr {@code{mod-muc-configuration} parameter} string name
22062 The name to return in service discovery responses.
22063 Defaults to @samp{"Prosody Chatrooms"}.
22066 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
22067 If @samp{#t}, this will only allow admins to create new chatrooms.
22068 Otherwise anyone can create a room. The value @samp{"local"} restricts room
22069 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
22070 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
22071 restricts to service administrators only.
22072 Defaults to @samp{#f}.
22075 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
22076 Maximum number of history messages that will be sent to the member that has
22077 just joined the room.
22078 Defaults to @samp{20}.
22085 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
22086 External components use XEP-0114, which most standalone components
22087 support. To add an external component, you simply fill the hostname field. See
22088 @url{https://prosody.im/doc/components}.
22089 Defaults to @samp{()}.
22091 Available @code{ext-component-configuration} fields are:
22093 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:
22094 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
22095 Password which the component will use to log in.
22098 @deftypevr {@code{ext-component-configuration} parameter} string hostname
22099 Hostname of the component.
22104 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
22105 Port(s) Prosody listens on for component connections.
22106 Defaults to @samp{(5347)}.
22109 @deftypevr {@code{prosody-configuration} parameter} string component-interface
22110 Interface Prosody listens on for component connections.
22111 Defaults to @samp{"127.0.0.1"}.
22114 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
22115 Raw content that will be added to the configuration file.
22118 It could be that you just want to get a @code{prosody.cfg.lua}
22119 up and running. In that case, you can pass an
22120 @code{opaque-prosody-configuration} record as the value of
22121 @code{prosody-service-type}. As its name indicates, an opaque configuration
22122 does not have easy reflective capabilities.
22123 Available @code{opaque-prosody-configuration} fields are:
22125 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
22126 The prosody package.
22129 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
22130 The contents of the @code{prosody.cfg.lua} to use.
22133 For example, if your @code{prosody.cfg.lua} is just the empty
22134 string, you could instantiate a prosody service like this:
22137 (service prosody-service-type
22138 (opaque-prosody-configuration
22139 (prosody.cfg.lua "")))
22142 @c end of Prosody auto-generated documentation
22144 @subsubheading BitlBee Service
22146 @cindex IRC (Internet Relay Chat)
22147 @cindex IRC gateway
22148 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
22149 interface to a variety of messaging protocols such as XMPP.
22151 @defvr {Scheme Variable} bitlbee-service-type
22152 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
22153 gateway daemon. Its value is a @code{bitlbee-configuration} (see
22156 To have BitlBee listen on port 6667 on localhost, add this line to your
22160 (service bitlbee-service-type)
22164 @deftp {Data Type} bitlbee-configuration
22165 This is the configuration for BitlBee, with the following fields:
22168 @item @code{interface} (default: @code{"127.0.0.1"})
22169 @itemx @code{port} (default: @code{6667})
22170 Listen on the network interface corresponding to the IP address
22171 specified in @var{interface}, on @var{port}.
22173 When @var{interface} is @code{127.0.0.1}, only local clients can
22174 connect; when it is @code{0.0.0.0}, connections can come from any
22175 networking interface.
22177 @item @code{bitlbee} (default: @code{bitlbee})
22178 The BitlBee package to use.
22180 @item @code{plugins} (default: @code{'()})
22181 List of plugin packages to use---e.g., @code{bitlbee-discord}.
22183 @item @code{extra-settings} (default: @code{""})
22184 Configuration snippet added as-is to the BitlBee configuration file.
22188 @subsubheading Quassel Service
22190 @cindex IRC (Internet Relay Chat)
22191 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
22192 meaning that one or more clients can attach to and detach from the
22195 @defvr {Scheme Variable} quassel-service-type
22196 This is the service type for the @url{https://quassel-irc.org/,Quassel}
22197 IRC backend daemon. Its value is a @code{quassel-configuration}
22201 @deftp {Data Type} quassel-configuration
22202 This is the configuration for Quassel, with the following fields:
22205 @item @code{quassel} (default: @code{quassel})
22206 The Quassel package to use.
22208 @item @code{interface} (default: @code{"::,0.0.0.0"})
22209 @item @code{port} (default: @code{4242})
22210 Listen on the network interface(s) corresponding to the IPv4 or IPv6
22211 interfaces specified in the comma delimited @var{interface}, on
22214 @item @code{loglevel} (default: @code{"Info"})
22215 The level of logging desired. Accepted values are Debug, Info, Warning
22220 @node Telephony Services
22221 @subsection Telephony Services
22223 @cindex Murmur (VoIP server)
22224 @cindex VoIP server
22225 This section describes how to set up and run a Murmur server. Murmur is
22226 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
22229 @deftp {Data Type} murmur-configuration
22230 The service type for the Murmur server. An example configuration can
22234 (service murmur-service-type
22235 (murmur-configuration
22237 "Welcome to this Mumble server running on Guix!")
22238 (cert-required? #t) ;disallow text password logins
22239 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
22240 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
22243 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
22244 password with the command that is printed during the activation phase.
22246 It is recommended to register a normal Mumble user account
22247 and grant it admin or moderator rights.
22248 You can use the @code{mumble} client to
22249 login as new normal user, register yourself, and log out.
22250 For the next step login with the name @code{SuperUser} use
22251 the @code{SuperUser} password that you set previously,
22252 and grant your newly registered mumble user administrator or moderator
22253 rights and create some channels.
22255 Available @code{murmur-configuration} fields are:
22258 @item @code{package} (default: @code{mumble})
22259 Package that contains @code{bin/murmurd}.
22261 @item @code{user} (default: @code{"murmur"})
22262 User who will run the Murmur server.
22264 @item @code{group} (default: @code{"murmur"})
22265 Group of the user who will run the murmur server.
22267 @item @code{port} (default: @code{64738})
22268 Port on which the server will listen.
22270 @item @code{welcome-text} (default: @code{""})
22271 Welcome text sent to clients when they connect.
22273 @item @code{server-password} (default: @code{""})
22274 Password the clients have to enter in order to connect.
22276 @item @code{max-users} (default: @code{100})
22277 Maximum of users that can be connected to the server at once.
22279 @item @code{max-user-bandwidth} (default: @code{#f})
22280 Maximum voice traffic a user can send per second.
22282 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
22283 File name of the sqlite database.
22284 The service's user will become the owner of the directory.
22286 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
22287 File name of the log file.
22288 The service's user will become the owner of the directory.
22290 @item @code{autoban-attempts} (default: @code{10})
22291 Maximum number of logins a user can make in @code{autoban-timeframe}
22292 without getting auto banned for @code{autoban-time}.
22294 @item @code{autoban-timeframe} (default: @code{120})
22295 Timeframe for autoban in seconds.
22297 @item @code{autoban-time} (default: @code{300})
22298 Amount of time in seconds for which a client gets banned
22299 when violating the autoban limits.
22301 @item @code{opus-threshold} (default: @code{100})
22302 Percentage of clients that need to support opus
22303 before switching over to opus audio codec.
22305 @item @code{channel-nesting-limit} (default: @code{10})
22306 How deep channels can be nested at maximum.
22308 @item @code{channelname-regex} (default: @code{#f})
22309 A string in form of a Qt regular expression that channel names must conform to.
22311 @item @code{username-regex} (default: @code{#f})
22312 A string in form of a Qt regular expression that user names must conform to.
22314 @item @code{text-message-length} (default: @code{5000})
22315 Maximum size in bytes that a user can send in one text chat message.
22317 @item @code{image-message-length} (default: @code{(* 128 1024)})
22318 Maximum size in bytes that a user can send in one image message.
22320 @item @code{cert-required?} (default: @code{#f})
22321 If it is set to @code{#t} clients that use weak password authentication
22322 will not be accepted. Users must have completed the certificate wizard to join.
22324 @item @code{remember-channel?} (default: @code{#f})
22325 Should murmur remember the last channel each user was in when they disconnected
22326 and put them into the remembered channel when they rejoin.
22328 @item @code{allow-html?} (default: @code{#f})
22329 Should html be allowed in text messages, user comments, and channel descriptions.
22331 @item @code{allow-ping?} (default: @code{#f})
22332 Setting to true exposes the current user count, the maximum user count, and
22333 the server's maximum bandwidth per client to unauthenticated users. In the
22334 Mumble client, this information is shown in the Connect dialog.
22336 Disabling this setting will prevent public listing of the server.
22338 @item @code{bonjour?} (default: @code{#f})
22339 Should the server advertise itself in the local network through the bonjour protocol.
22341 @item @code{send-version?} (default: @code{#f})
22342 Should the murmur server version be exposed in ping requests.
22344 @item @code{log-days} (default: @code{31})
22345 Murmur also stores logs in the database, which are accessible via RPC.
22346 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
22347 or -1 to disable logging to the database.
22349 @item @code{obfuscate-ips?} (default: @code{#t})
22350 Should logged ips be obfuscated to protect the privacy of users.
22352 @item @code{ssl-cert} (default: @code{#f})
22353 File name of the SSL/TLS certificate used for encrypted connections.
22356 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
22358 @item @code{ssl-key} (default: @code{#f})
22359 Filepath to the ssl private key used for encrypted connections.
22361 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
22364 @item @code{ssl-dh-params} (default: @code{#f})
22365 File name of a PEM-encoded file with Diffie-Hellman parameters
22366 for the SSL/TLS encryption. Alternatively you set it to
22367 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
22368 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
22370 @item @code{ssl-ciphers} (default: @code{#f})
22371 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
22374 This option is specified using
22375 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
22376 OpenSSL cipher list notation}.
22378 It is recommended that you try your cipher string using 'openssl ciphers <string>'
22379 before setting it here, to get a feel for which cipher suites you will get.
22380 After setting this option, it is recommend that you inspect your Murmur log
22381 to ensure that Murmur is using the cipher suites that you expected it to.
22383 Note: Changing this option may impact the backwards compatibility of your
22384 Murmur server, and can remove the ability for older Mumble clients to be able
22387 @item @code{public-registration} (default: @code{#f})
22388 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
22390 You can optionally register your server in the public server list that the
22391 @code{mumble} client shows on startup.
22392 You cannot register your server if you have set a @code{server-password},
22393 or set @code{allow-ping} to @code{#f}.
22395 It might take a few hours until it shows up in the public list.
22397 @item @code{file} (default: @code{#f})
22398 Optional alternative override for this configuration.
22402 @deftp {Data Type} murmur-public-registration-configuration
22403 Configuration for public registration of a murmur service.
22407 This is a display name for your server. Not to be confused with the hostname.
22409 @item @code{password}
22410 A password to identify your registration.
22411 Subsequent updates will need the same password. Don't lose your password.
22414 This should be a @code{http://} or @code{https://} link to your web
22417 @item @code{hostname} (default: @code{#f})
22418 By default your server will be listed by its IP address.
22419 If it is set your server will be linked by this host name instead.
22425 @node File-Sharing Services
22426 @subsection File-Sharing Services
22428 The @code{(gnu services file-sharing)} module provides services that
22429 assist with transferring files over peer-to-peer file-sharing networks.
22431 @subsubheading Transmission Daemon Service
22433 @uref{https://transmissionbt.com/, Transmission} is a flexible
22434 BitTorrent client that offers a variety of graphical and command-line
22435 interfaces. A @code{transmission-daemon-service-type} service provides
22436 Transmission's headless variant, @command{transmission-daemon}, as a
22437 system service, allowing users to share files via BitTorrent even when
22438 they are not logged in.
22440 @deffn {Scheme Variable} transmission-daemon-service-type
22441 The service type for the Transmission Daemon BitTorrent client. Its
22442 value must be a @code{transmission-daemon-configuration} object as in
22446 (service transmission-daemon-service-type
22447 (transmission-daemon-configuration
22448 ;; Restrict access to the RPC ("control") interface
22449 (rpc-authentication-required? #t)
22450 (rpc-username "transmission")
22452 (transmission-password-hash
22453 "transmission" ; desired password
22454 "uKd1uMs9")) ; arbitrary salt value
22456 ;; Accept requests from this and other hosts on the
22458 (rpc-whitelist-enabled? #t)
22459 (rpc-whitelist '("::1" "127.0.0.1" "192.168.0.*"))
22461 ;; Limit bandwidth use during work hours
22462 (alt-speed-down (* 1024 2)) ; 2 MB/s
22463 (alt-speed-up 512) ; 512 kB/s
22465 (alt-speed-time-enabled? #t)
22466 (alt-speed-time-day 'weekdays)
22467 (alt-speed-time-begin
22468 (+ (* 60 8) 30)) ; 8:30 am
22469 (alt-speed-time-end
22470 (+ (* 60 (+ 12 5)) 30)))) ; 5:30 pm
22474 Once the service is started, users can interact with the daemon through
22475 its Web interface (at @code{http://localhost:9091/}) or by using the
22476 @command{transmission-remote} command-line tool, available in the
22477 @code{transmission} package. (Emacs users may want to also consider the
22478 @code{emacs-transmission} package.) Both communicate with the daemon
22479 through its remote procedure call (RPC) interface, which by default is
22480 available to all users on the system; you may wish to change this by
22481 assigning values to the @code{rpc-authentication-required?},
22482 @code{rpc-username} and @code{rpc-password} settings, as shown in the
22483 example above and documented further below.
22485 The value for @code{rpc-password} must be a password hash of the type
22486 generated and used by Transmission clients. This can be copied verbatim
22487 from an existing @file{settings.json} file, if another Transmission
22488 client is already being used. Otherwise, the
22489 @code{transmission-password-hash} and @code{transmission-random-salt}
22490 procedures provided by this module can be used to obtain a suitable hash
22493 @deffn {Scheme Procedure} transmission-password-hash @var{password} @var{salt}
22494 Returns a string containing the result of hashing @var{password}
22495 together with @var{salt}, in the format recognized by Transmission
22496 clients for their @code{rpc-password} configuration setting.
22498 @var{salt} must be an eight-character string. The
22499 @code{transmission-random-salt} procedure can be used to generate a
22500 suitable salt value at random.
22503 @deffn {Scheme Procedure} transmission-random-salt
22504 Returns a string containing a random, eight-character salt value of the
22505 type generated and used by Transmission clients, suitable for passing to
22506 the @code{transmission-password-hash} procedure.
22509 These procedures are accessible from within a Guile REPL started with
22510 the @command{guix repl} command (@pxref{Invoking guix repl}). This is
22511 useful for obtaining a random salt value to provide as the second
22512 parameter to `transmission-password-hash`, as in this example session:
22516 scheme@@(guix-user)> ,use (gnu services file-sharing)
22517 scheme@@(guix-user)> (transmission-random-salt)
22521 Alternatively, a complete password hash can generated in a single step:
22524 scheme@@(guix-user)> (transmission-password-hash "transmission"
22525 (transmission-random-salt))
22526 $2 = "@{c8bbc6d1740cd8dc819a6e25563b67812c1c19c9VtFPfdsX"
22529 The resulting string can be used as-is for the value of
22530 @code{rpc-password}, allowing the password to be kept hidden even in the
22531 operating-system configuration.
22533 Torrent files downloaded by the daemon are directly accessible only to
22534 users in the ``transmission'' user group, who receive read-only access
22535 to the directory specified by the @code{download-dir} configuration
22536 setting (and also the directory specified by @code{incomplete-dir}, if
22537 @code{incomplete-dir-enabled?} is @code{#t}). Downloaded files can be
22538 moved to another directory or deleted altogether using
22539 @command{transmission-remote} with its @code{--move} and
22540 @code{--remove-and-delete} options.
22542 If the @code{watch-dir-enabled?} setting is set to @code{#t}, users in
22543 the ``transmission'' group are able also to place @file{.torrent} files
22544 in the directory specified by @code{watch-dir} to have the corresponding
22545 torrents added by the daemon. (The @code{trash-original-torrent-files?}
22546 setting controls whether the daemon deletes these files after processing
22549 Some of the daemon's configuration settings can be changed temporarily
22550 by @command{transmission-remote} and similar tools. To undo these
22551 changes, use the service's @code{reload} action to have the daemon
22552 reload its settings from disk:
22555 # herd reload transmission-daemon
22558 The full set of available configuration settings is defined by the
22559 @code{transmission-daemon-configuration} data type.
22561 @deftp {Data Type} transmission-daemon-configuration
22562 The data type representing configuration settings for Transmission
22563 Daemon. These correspond directly to the settings recognized by
22564 Transmission clients in their @file{settings.json} file.
22567 @c The following documentation was initially generated by
22568 @c (generate-transmission-daemon-documentation) in (gnu services
22569 @c file-sharing). Manually maintained documentation is better, so we
22570 @c shouldn't hesitate to edit below as needed. However if the change
22571 @c you want to make to this documentation can be done in an automated
22572 @c way, it's probably easier to change (generate-documentation) than to
22573 @c make it below and have to deal with the churn as Transmission Daemon
22576 @c %start of fragment
22578 Available @code{transmission-daemon-configuration} fields are:
22580 @deftypevr {@code{transmission-daemon-configuration} parameter} package transmission
22581 The Transmission package to use.
22585 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer stop-wait-period
22586 The period, in seconds, to wait when stopping the service for
22587 @command{transmission-daemon} to exit before killing its process. This
22588 allows the daemon time to complete its housekeeping and send a final
22589 update to trackers as it shuts down. On slow hosts, or hosts with a
22590 slow network connection, this value may need to be increased.
22592 Defaults to @samp{10}.
22596 @deftypevr {@code{transmission-daemon-configuration} parameter} string download-dir
22597 The directory to which torrent files are downloaded.
22599 Defaults to @samp{"/var/lib/transmission-daemon/downloads"}.
22603 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean incomplete-dir-enabled?
22604 If @code{#t}, files will be held in @code{incomplete-dir} while their
22605 torrent is being downloaded, then moved to @code{download-dir} once the
22606 torrent is complete. Otherwise, files for all torrents (including those
22607 still being downloaded) will be placed in @code{download-dir}.
22609 Defaults to @samp{#f}.
22613 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string incomplete-dir
22614 The directory in which files from incompletely downloaded torrents will
22615 be held when @code{incomplete-dir-enabled?} is @code{#t}.
22617 Defaults to @samp{disabled}.
22621 @deftypevr {@code{transmission-daemon-configuration} parameter} umask umask
22622 The file mode creation mask used for downloaded files. (See the
22623 @command{umask} man page for more information.)
22625 Defaults to @samp{18}.
22629 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rename-partial-files?
22630 When @code{#t}, ``.part'' is appended to the name of partially
22633 Defaults to @samp{#t}.
22637 @deftypevr {@code{transmission-daemon-configuration} parameter} preallocation-mode preallocation
22638 The mode by which space should be preallocated for downloaded files, one
22639 of @code{none}, @code{fast} (or @code{sparse}) and @code{full}.
22640 Specifying @code{full} will minimize disk fragmentation at a cost to
22641 file-creation speed.
22643 Defaults to @samp{fast}.
22647 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean watch-dir-enabled?
22648 If @code{#t}, the directory specified by @code{watch-dir} will be
22649 watched for new @file{.torrent} files and the torrents they describe
22650 added automatically (and the original files removed, if
22651 @code{trash-original-torrent-files?} is @code{#t}).
22653 Defaults to @samp{#f}.
22657 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string watch-dir
22658 The directory to be watched for @file{.torrent} files indicating new
22659 torrents to be added, when @code{watch-dir-enabled} is @code{#t}.
22661 Defaults to @samp{disabled}.
22665 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean trash-original-torrent-files?
22666 When @code{#t}, @file{.torrent} files will be deleted from the watch
22667 directory once their torrent has been added (see
22668 @code{watch-directory-enabled?}).
22670 Defaults to @samp{#f}.
22674 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-down-enabled?
22675 When @code{#t}, the daemon's download speed will be limited to the rate
22676 specified by @code{speed-limit-down}.
22678 Defaults to @samp{#f}.
22682 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-down
22683 The default global-maximum download speed, in kilobytes per second.
22685 Defaults to @samp{100}.
22689 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-up-enabled?
22690 When @code{#t}, the daemon's upload speed will be limited to the rate
22691 specified by @code{speed-limit-up}.
22693 Defaults to @samp{#f}.
22697 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-up
22698 The default global-maximum upload speed, in kilobytes per second.
22700 Defaults to @samp{100}.
22704 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-enabled?
22705 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
22706 @code{alt-speed-up} are used (in place of @code{speed-limit-down} and
22707 @code{speed-limit-up}, if they are enabled) to constrain the daemon's
22708 bandwidth usage. This can be scheduled to occur automatically at
22709 certain times during the week; see @code{alt-speed-time-enabled?}.
22711 Defaults to @samp{#f}.
22715 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-down
22716 The alternate global-maximum download speed, in kilobytes per second.
22718 Defaults to @samp{50}.
22722 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-up
22723 The alternate global-maximum upload speed, in kilobytes per second.
22725 Defaults to @samp{50}.
22729 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-time-enabled?
22730 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
22731 @code{alt-speed-up} will be enabled automatically during the periods
22732 specified by @code{alt-speed-time-day}, @code{alt-speed-time-begin} and
22733 @code{alt-time-speed-end}.
22735 Defaults to @samp{#f}.
22739 @deftypevr {@code{transmission-daemon-configuration} parameter} day-list alt-speed-time-day
22740 The days of the week on which the alternate-speed schedule should be
22741 used, specified either as a list of days (@code{sunday}, @code{monday},
22742 and so on) or using one of the symbols @code{weekdays}, @code{weekends}
22745 Defaults to @samp{all}.
22749 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-begin
22750 The time of day at which to enable the alternate speed limits, expressed
22751 as a number of minutes since midnight.
22753 Defaults to @samp{540}.
22757 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-end
22758 The time of day at which to disable the alternate speed limits,
22759 expressed as a number of minutes since midnight.
22761 Defaults to @samp{1020}.
22765 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv4
22766 The IP address at which to listen for peer connections, or ``0.0.0.0''
22767 to listen at all available IP addresses.
22769 Defaults to @samp{"0.0.0.0"}.
22773 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv6
22774 The IPv6 address at which to listen for peer connections, or ``::'' to
22775 listen at all available IPv6 addresses.
22777 Defaults to @samp{"::"}.
22781 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean peer-port-random-on-start?
22782 If @code{#t}, when the daemon starts it will select a port at random on
22783 which to listen for peer connections, from the range specified
22784 (inclusively) by @code{peer-port-random-low} and
22785 @code{peer-port-random-high}. Otherwise, it listens on the port
22786 specified by @code{peer-port}.
22788 Defaults to @samp{#f}.
22792 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-low
22793 The lowest selectable port number when @code{peer-port-random-on-start?}
22796 Defaults to @samp{49152}.
22800 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-high
22801 The highest selectable port number when @code{peer-port-random-on-start}
22804 Defaults to @samp{65535}.
22808 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port
22809 The port on which to listen for peer connections when
22810 @code{peer-port-random-on-start?} is @code{#f}.
22812 Defaults to @samp{51413}.
22816 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean port-forwarding-enabled?
22817 If @code{#t}, the daemon will attempt to configure port-forwarding on an
22818 upstream gateway automatically using @acronym{UPnP} and
22821 Defaults to @samp{#t}.
22825 @deftypevr {@code{transmission-daemon-configuration} parameter} encryption-mode encryption
22826 The encryption preference for peer connections, one of
22827 @code{prefer-unencrypted-connections},
22828 @code{prefer-encrypted-connections} or
22829 @code{require-encrypted-connections}.
22831 Defaults to @samp{prefer-encrypted-connections}.
22835 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string peer-congestion-algorithm
22836 The TCP congestion-control algorithm to use for peer connections,
22837 specified using a string recognized by the operating system in calls to
22838 @code{setsockopt} (or set to @code{disabled}, in which case the
22839 operating-system default is used).
22841 Note that on GNU/Linux systems, the kernel must be configured to allow
22842 processes to use a congestion-control algorithm not in the default set;
22843 otherwise, it will deny these requests with ``Operation not permitted''.
22844 To see which algorithms are available on your system and which are
22845 currently permitted for use, look at the contents of the files
22846 @file{tcp_available_congestion_control} and
22847 @file{tcp_allowed_congestion_control} in the @file{/proc/sys/net/ipv4}
22850 As an example, to have Transmission Daemon use
22851 @uref{http://www-ece.rice.edu/networks/TCP-LP/,the TCP Low Priority
22852 congestion-control algorithm}, you'll need to modify your kernel
22853 configuration to build in support for the algorithm, then update your
22854 operating-system configuration to allow its use by adding a
22855 @code{sysctl-service-type} service (or updating the existing one's
22856 configuration) with lines like the following:
22859 (service sysctl-service-type
22860 (sysctl-configuration
22862 ("net.ipv4.tcp_allowed_congestion_control" .
22863 "reno cubic lp"))))
22866 The Transmission Daemon configuration can then be updated with
22869 (peer-congestion-algorithm "lp")
22872 and the system reconfigured to have the changes take effect.
22874 Defaults to @samp{disabled}.
22878 @deftypevr {@code{transmission-daemon-configuration} parameter} tcp-type-of-service peer-socket-tos
22879 The type of service to request in outgoing @acronym{TCP} packets, one of
22880 @code{default}, @code{low-cost}, @code{throughput}, @code{low-delay} and
22881 @code{reliability}.
22883 Defaults to @samp{default}.
22887 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-global
22888 The global limit on the number of connected peers.
22890 Defaults to @samp{200}.
22894 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-per-torrent
22895 The per-torrent limit on the number of connected peers.
22897 Defaults to @samp{50}.
22901 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer upload-slots-per-torrent
22902 The maximum number of peers to which the daemon will upload data
22903 simultaneously for each torrent.
22905 Defaults to @samp{14}.
22909 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-id-ttl-hours
22910 The maximum lifespan, in hours, of the peer ID associated with each
22911 public torrent before it is regenerated.
22913 Defaults to @samp{6}.
22917 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean blocklist-enabled?
22918 When @code{#t}, the daemon will ignore peers mentioned in the blocklist
22919 it has most recently downloaded from @code{blocklist-url}.
22921 Defaults to @samp{#f}.
22925 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string blocklist-url
22926 The URL of a peer blocklist (in @acronym{P2P}-plaintext or eMule
22927 @file{.dat} format) to be periodically downloaded and applied when
22928 @code{blocklist-enabled?} is @code{#t}.
22930 Defaults to @samp{disabled}.
22934 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean download-queue-enabled?
22935 If @code{#t}, the daemon will be limited to downloading at most
22936 @code{download-queue-size} non-stalled torrents simultaneously.
22938 Defaults to @samp{#t}.
22942 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer download-queue-size
22943 The size of the daemon's download queue, which limits the number of
22944 non-stalled torrents it will download at any one time when
22945 @code{download-queue-enabled?} is @code{#t}.
22947 Defaults to @samp{5}.
22951 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean seed-queue-enabled?
22952 If @code{#t}, the daemon will be limited to seeding at most
22953 @code{seed-queue-size} non-stalled torrents simultaneously.
22955 Defaults to @samp{#f}.
22959 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer seed-queue-size
22960 The size of the daemon's seed queue, which limits the number of
22961 non-stalled torrents it will seed at any one time when
22962 @code{seed-queue-enabled?} is @code{#t}.
22964 Defaults to @samp{10}.
22968 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean queue-stalled-enabled?
22969 When @code{#t}, the daemon will consider torrents for which it has not
22970 shared data in the past @code{queue-stalled-minutes} minutes to be
22971 stalled and not count them against its @code{download-queue-size} and
22972 @code{seed-queue-size} limits.
22974 Defaults to @samp{#t}.
22978 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer queue-stalled-minutes
22979 The maximum period, in minutes, a torrent may be idle before it is
22980 considered to be stalled, when @code{queue-stalled-enabled?} is
22983 Defaults to @samp{30}.
22987 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean ratio-limit-enabled?
22988 When @code{#t}, a torrent being seeded will automatically be paused once
22989 it reaches the ratio specified by @code{ratio-limit}.
22991 Defaults to @samp{#f}.
22995 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-rational ratio-limit
22996 The ratio at which a torrent being seeded will be paused, when
22997 @code{ratio-limit-enabled?} is @code{#t}.
22999 Defaults to @samp{2.0}.
23003 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean idle-seeding-limit-enabled?
23004 When @code{#t}, a torrent being seeded will automatically be paused once
23005 it has been idle for @code{idle-seeding-limit} minutes.
23007 Defaults to @samp{#f}.
23011 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer idle-seeding-limit
23012 The maximum period, in minutes, a torrent being seeded may be idle
23013 before it is paused, when @code{idle-seeding-limit-enabled?} is
23016 Defaults to @samp{30}.
23020 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean dht-enabled?
23021 Enable @uref{http://bittorrent.org/beps/bep_0005.html,the distributed
23022 hash table (@acronym{DHT}) protocol}, which supports the use of
23023 trackerless torrents.
23025 Defaults to @samp{#t}.
23029 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean lpd-enabled?
23030 Enable @uref{https://en.wikipedia.org/wiki/Local_Peer_Discovery,local
23031 peer discovery} (@acronym{LPD}), which allows the discovery of peers on
23032 the local network and may reduce the amount of data sent over the public
23035 Defaults to @samp{#f}.
23039 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean pex-enabled?
23040 Enable @uref{https://en.wikipedia.org/wiki/Peer_exchange,peer exchange}
23041 (@acronym{PEX}), which reduces the daemon's reliance on external
23042 trackers and may improve its performance.
23044 Defaults to @samp{#t}.
23048 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean utp-enabled?
23049 Enable @uref{http://bittorrent.org/beps/bep_0029.html,the micro
23050 transport protocol} (@acronym{uTP}), which aims to reduce the impact of
23051 BitTorrent traffic on other users of the local network while maintaining
23052 full utilization of the available bandwidth.
23054 Defaults to @samp{#t}.
23058 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-enabled?
23059 If @code{#t}, enable the remote procedure call (@acronym{RPC})
23060 interface, which allows remote control of the daemon via its Web
23061 interface, the @command{transmission-remote} command-line client, and
23064 Defaults to @samp{#t}.
23068 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-bind-address
23069 The IP address at which to listen for @acronym{RPC} connections, or
23070 ``0.0.0.0'' to listen at all available IP addresses.
23072 Defaults to @samp{"0.0.0.0"}.
23076 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number rpc-port
23077 The port on which to listen for @acronym{RPC} connections.
23079 Defaults to @samp{9091}.
23083 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-url
23084 The path prefix to use in the @acronym{RPC}-endpoint @acronym{URL}.
23086 Defaults to @samp{"/transmission/"}.
23090 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-authentication-required?
23091 When @code{#t}, clients must authenticate (see @code{rpc-username} and
23092 @code{rpc-password}) when using the @acronym{RPC} interface. Note this
23093 has the side effect of disabling host-name whitelisting (see
23094 @code{rpc-host-whitelist-enabled?}.
23096 Defaults to @samp{#f}.
23100 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string rpc-username
23101 The username required by clients to access the @acronym{RPC} interface
23102 when @code{rpc-authentication-required?} is @code{#t}.
23104 Defaults to @samp{disabled}.
23108 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-transmission-password-hash rpc-password
23109 The password required by clients to access the @acronym{RPC} interface
23110 when @code{rpc-authentication-required?} is @code{#t}. This must be
23111 specified using a password hash in the format recognized by Transmission
23112 clients, either copied from an existing @file{settings.json} file or
23113 generated using the @code{transmission-password-hash} procedure.
23115 Defaults to @samp{disabled}.
23119 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-whitelist-enabled?
23120 When @code{#t}, @acronym{RPC} requests will be accepted only when they
23121 originate from an address specified in @code{rpc-whitelist}.
23123 Defaults to @samp{#t}.
23127 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-whitelist
23128 The list of IP and IPv6 addresses from which @acronym{RPC} requests will
23129 be accepted when @code{rpc-whitelist-enabled?} is @code{#t}. Wildcards
23130 may be specified using @samp{*}.
23132 Defaults to @samp{("127.0.0.1" "::1")}.
23136 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-host-whitelist-enabled?
23137 When @code{#t}, @acronym{RPC} requests will be accepted only when they
23138 are addressed to a host named in @code{rpc-host-whitelist}. Note that
23139 requests to ``localhost'' or ``localhost.'', or to a numeric address,
23140 are always accepted regardless of these settings.
23142 Note also this functionality is disabled when
23143 @code{rpc-authentication-required?} is @code{#t}.
23145 Defaults to @samp{#t}.
23149 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-host-whitelist
23150 The list of host names recognized by the @acronym{RPC} server when
23151 @code{rpc-host-whitelist-enabled?} is @code{#t}.
23153 Defaults to @samp{()}.
23157 @deftypevr {@code{transmission-daemon-configuration} parameter} message-level message-level
23158 The minimum severity level of messages to be logged (to
23159 @file{/var/log/transmission.log}) by the daemon, one of @code{none} (no
23160 logging), @code{error}, @code{info} and @code{debug}.
23162 Defaults to @samp{info}.
23166 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean start-added-torrents?
23167 When @code{#t}, torrents are started as soon as they are added;
23168 otherwise, they are added in ``paused'' state.
23170 Defaults to @samp{#t}.
23174 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean script-torrent-done-enabled?
23175 When @code{#t}, the script specified by
23176 @code{script-torrent-done-filename} will be invoked each time a torrent
23179 Defaults to @samp{#f}.
23183 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-file-object script-torrent-done-filename
23184 A file name or file-like object specifying a script to run each time a
23185 torrent completes, when @code{script-torrent-done-enabled?} is
23188 Defaults to @samp{disabled}.
23192 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean scrape-paused-torrents-enabled?
23193 When @code{#t}, the daemon will scrape trackers for a torrent even when
23194 the torrent is paused.
23196 Defaults to @samp{#t}.
23200 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer cache-size-mb
23201 The amount of memory, in megabytes, to allocate for the daemon's
23202 in-memory cache. A larger value may increase performance by reducing
23203 the frequency of disk I/O.
23205 Defaults to @samp{4}.
23209 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean prefetch-enabled?
23210 When @code{#t}, the daemon will try to improve I/O performance by
23211 hinting to the operating system which data is likely to be read next
23212 from disk to satisfy requests from peers.
23214 Defaults to @samp{#t}.
23219 @c %end of fragment
23223 @node Monitoring Services
23224 @subsection Monitoring Services
23226 @subsubheading Tailon Service
23228 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
23229 viewing and searching log files.
23231 The following example will configure the service with default values.
23232 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
23235 (service tailon-service-type)
23238 The following example customises more of the Tailon configuration,
23239 adding @command{sed} to the list of allowed commands.
23242 (service tailon-service-type
23243 (tailon-configuration
23245 (tailon-configuration-file
23246 (allowed-commands '("tail" "grep" "awk" "sed"))))))
23250 @deftp {Data Type} tailon-configuration
23251 Data type representing the configuration of Tailon.
23252 This type has the following parameters:
23255 @item @code{config-file} (default: @code{(tailon-configuration-file)})
23256 The configuration file to use for Tailon. This can be set to a
23257 @dfn{tailon-configuration-file} record value, or any gexp
23258 (@pxref{G-Expressions}).
23260 For example, to instead use a local file, the @code{local-file} function
23264 (service tailon-service-type
23265 (tailon-configuration
23266 (config-file (local-file "./my-tailon.conf"))))
23269 @item @code{package} (default: @code{tailon})
23270 The tailon package to use.
23275 @deftp {Data Type} tailon-configuration-file
23276 Data type representing the configuration options for Tailon.
23277 This type has the following parameters:
23280 @item @code{files} (default: @code{(list "/var/log")})
23281 List of files to display. The list can include strings for a single file
23282 or directory, or a list, where the first item is the name of a
23283 subsection, and the remaining items are the files or directories in that
23286 @item @code{bind} (default: @code{"localhost:8080"})
23287 Address and port to which Tailon should bind on.
23289 @item @code{relative-root} (default: @code{#f})
23290 URL path to use for Tailon, set to @code{#f} to not use a path.
23292 @item @code{allow-transfers?} (default: @code{#t})
23293 Allow downloading the log files in the web interface.
23295 @item @code{follow-names?} (default: @code{#t})
23296 Allow tailing of not-yet existent files.
23298 @item @code{tail-lines} (default: @code{200})
23299 Number of lines to read initially from each file.
23301 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
23302 Commands to allow running. By default, @code{sed} is disabled.
23304 @item @code{debug?} (default: @code{#f})
23305 Set @code{debug?} to @code{#t} to show debug messages.
23307 @item @code{wrap-lines} (default: @code{#t})
23308 Initial line wrapping state in the web interface. Set to @code{#t} to
23309 initially wrap lines (the default), or to @code{#f} to initially not
23312 @item @code{http-auth} (default: @code{#f})
23313 HTTP authentication type to use. Set to @code{#f} to disable
23314 authentication (the default). Supported values are @code{"digest"} or
23317 @item @code{users} (default: @code{#f})
23318 If HTTP authentication is enabled (see @code{http-auth}), access will be
23319 restricted to the credentials provided here. To configure users, use a
23320 list of pairs, where the first element of the pair is the username, and
23321 the 2nd element of the pair is the password.
23324 (tailon-configuration-file
23325 (http-auth "basic")
23326 (users '(("user1" . "password1")
23327 ("user2" . "password2"))))
23334 @subsubheading Darkstat Service
23336 Darkstat is a packet sniffer that captures network traffic, calculates
23337 statistics about usage, and serves reports over HTTP.
23339 @defvar {Scheme Variable} darkstat-service-type
23340 This is the service type for the
23341 @uref{https://unix4lyfe.org/darkstat/, darkstat}
23342 service, its value must be a @code{darkstat-configuration} record as in
23346 (service darkstat-service-type
23347 (darkstat-configuration
23348 (interface "eno1")))
23352 @deftp {Data Type} darkstat-configuration
23353 Data type representing the configuration of @command{darkstat}.
23356 @item @code{package} (default: @code{darkstat})
23357 The darkstat package to use.
23359 @item @code{interface}
23360 Capture traffic on the specified network interface.
23362 @item @code{port} (default: @code{"667"})
23363 Bind the web interface to the specified port.
23365 @item @code{bind-address} (default: @code{"127.0.0.1"})
23366 Bind the web interface to the specified address.
23368 @item @code{base} (default: @code{"/"})
23369 Specify the path of the base URL@. This can be useful if
23370 @command{darkstat} is accessed via a reverse proxy.
23375 @subsubheading Prometheus Node Exporter Service
23377 @cindex prometheus-node-exporter
23378 The Prometheus ``node exporter'' makes hardware and operating system statistics
23379 provided by the Linux kernel available for the Prometheus monitoring system.
23380 This service should be deployed on all physical nodes and virtual machines,
23381 where monitoring these statistics is desirable.
23383 @defvar {Scheme variable} prometheus-node-exporter-service-type
23384 This is the service type for the
23385 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
23386 service, its value must be a @code{prometheus-node-exporter-configuration}.
23389 (service prometheus-node-exporter-service-type)
23393 @deftp {Data Type} prometheus-node-exporter-configuration
23394 Data type representing the configuration of @command{node_exporter}.
23397 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
23398 The prometheus-node-exporter package to use.
23400 @item @code{web-listen-address} (default: @code{":9100"})
23401 Bind the web interface to the specified address.
23403 @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
23404 This directory can be used to export metrics specific to this machine.
23405 Files containing metrics in the text format, with the filename ending in
23406 @code{.prom} should be placed in this directory.
23408 @item @code{extra-options} (default: @code{'()})
23409 Extra options to pass to the Prometheus node exporter.
23414 @subsubheading Zabbix server
23415 @cindex zabbix zabbix-server
23416 Zabbix provides monitoring metrics, among others network utilization, CPU load
23417 and disk space consumption:
23420 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
23421 @item Auto-discovery of servers and network devices and interfaces.
23422 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
23423 @item Distributed monitoring with centralized web administration.
23424 @item Native high performance agents.
23425 @item SLA, and ITIL KPI metrics on reporting.
23426 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
23427 @item Remote command execution through Zabbix proxies.
23430 @c %start of fragment
23432 Available @code{zabbix-server-configuration} fields are:
23434 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
23435 The zabbix-server package.
23439 @deftypevr {@code{zabbix-server-configuration} parameter} string user
23440 User who will run the Zabbix server.
23442 Defaults to @samp{"zabbix"}.
23446 @deftypevr {@code{zabbix-server-configuration} parameter} group group
23447 Group who will run the Zabbix server.
23449 Defaults to @samp{"zabbix"}.
23453 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
23454 Database host name.
23456 Defaults to @samp{"127.0.0.1"}.
23460 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
23463 Defaults to @samp{"zabbix"}.
23467 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
23470 Defaults to @samp{"zabbix"}.
23474 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
23475 Database password. Please, use @code{include-files} with
23476 @code{DBPassword=SECRET} inside a specified file instead.
23478 Defaults to @samp{""}.
23482 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
23485 Defaults to @samp{5432}.
23489 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
23490 Specifies where log messages are written to:
23494 @code{system} - syslog.
23497 @code{file} - file specified with @code{log-file} parameter.
23500 @code{console} - standard output.
23504 Defaults to @samp{""}.
23508 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
23509 Log file name for @code{log-type} @code{file} parameter.
23511 Defaults to @samp{"/var/log/zabbix/server.log"}.
23515 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
23518 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
23522 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
23523 The location of certificate authority (CA) files for SSL server
23524 certificate verification.
23526 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
23530 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
23531 Location of SSL client certificates.
23533 Defaults to @samp{"/etc/ssl/certs"}.
23537 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
23538 Extra options will be appended to Zabbix server configuration file.
23540 Defaults to @samp{""}.
23544 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
23545 You may include individual files or all files in a directory in the
23546 configuration file.
23548 Defaults to @samp{()}.
23552 @c %end of fragment
23554 @subsubheading Zabbix agent
23555 @cindex zabbix zabbix-agent
23557 Zabbix agent gathers information for Zabbix server.
23559 @c %start of fragment
23561 Available @code{zabbix-agent-configuration} fields are:
23563 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
23564 The zabbix-agent package.
23568 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
23569 User who will run the Zabbix agent.
23571 Defaults to @samp{"zabbix"}.
23575 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
23576 Group who will run the Zabbix agent.
23578 Defaults to @samp{"zabbix"}.
23582 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
23583 Unique, case sensitive hostname which is required for active checks and
23584 must match hostname as configured on the server.
23586 Defaults to @samp{""}.
23590 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
23591 Specifies where log messages are written to:
23595 @code{system} - syslog.
23598 @code{file} - file specified with @code{log-file} parameter.
23601 @code{console} - standard output.
23605 Defaults to @samp{""}.
23609 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
23610 Log file name for @code{log-type} @code{file} parameter.
23612 Defaults to @samp{"/var/log/zabbix/agent.log"}.
23616 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
23619 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
23623 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
23624 List of IP addresses, optionally in CIDR notation, or hostnames of
23625 Zabbix servers and Zabbix proxies. Incoming connections will be
23626 accepted only from the hosts listed here.
23628 Defaults to @samp{("127.0.0.1")}.
23632 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
23633 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
23634 proxies for active checks. If port is not specified, default port is
23635 used. If this parameter is not specified, active checks are disabled.
23637 Defaults to @samp{("127.0.0.1")}.
23641 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
23642 Extra options will be appended to Zabbix server configuration file.
23644 Defaults to @samp{""}.
23648 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
23649 You may include individual files or all files in a directory in the
23650 configuration file.
23652 Defaults to @samp{()}.
23656 @c %end of fragment
23658 @subsubheading Zabbix front-end
23659 @cindex zabbix zabbix-front-end
23661 This service provides a WEB interface to Zabbix server.
23663 @c %start of fragment
23665 Available @code{zabbix-front-end-configuration} fields are:
23667 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
23668 NGINX configuration.
23672 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
23673 Database host name.
23675 Defaults to @samp{"localhost"}.
23679 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
23682 Defaults to @samp{5432}.
23686 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
23689 Defaults to @samp{"zabbix"}.
23693 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
23696 Defaults to @samp{"zabbix"}.
23700 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
23701 Database password. Please, use @code{db-secret-file} instead.
23703 Defaults to @samp{""}.
23707 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
23708 Secret file containing the credentials for the Zabbix front-end. The value
23709 must be a local file name, not a G-expression. You are expected to create
23710 this file manually. Its contents will be copied into @file{zabbix.conf.php}
23711 as the value of @code{$DB['PASSWORD']}.
23713 Defaults to @samp{""}.
23717 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
23718 Zabbix server hostname.
23720 Defaults to @samp{"localhost"}.
23724 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
23725 Zabbix server port.
23727 Defaults to @samp{10051}.
23732 @c %end of fragment
23734 @node Kerberos Services
23735 @subsection Kerberos Services
23738 The @code{(gnu services kerberos)} module provides services relating to
23739 the authentication protocol @dfn{Kerberos}.
23741 @subsubheading Krb5 Service
23743 Programs using a Kerberos client library normally
23744 expect a configuration file in @file{/etc/krb5.conf}.
23745 This service generates such a file from a definition provided in the
23746 operating system declaration.
23747 It does not cause any daemon to be started.
23749 No ``keytab'' files are provided by this service---you must explicitly create them.
23750 This service is known to work with the MIT client library, @code{mit-krb5}.
23751 Other implementations have not been tested.
23753 @defvr {Scheme Variable} krb5-service-type
23754 A service type for Kerberos 5 clients.
23758 Here is an example of its use:
23760 (service krb5-service-type
23761 (krb5-configuration
23762 (default-realm "EXAMPLE.COM")
23763 (allow-weak-crypto? #t)
23766 (name "EXAMPLE.COM")
23767 (admin-server "groucho.example.com")
23768 (kdc "karl.example.com"))
23771 (admin-server "kerb-admin.argrx.edu")
23772 (kdc "keys.argrx.edu"))))))
23776 This example provides a Kerberos@tie{}5 client configuration which:
23778 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
23779 of which have distinct administration servers and key distribution centers;
23780 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
23781 specified by clients;
23782 @item Accepts services which only support encryption types known to be weak.
23785 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
23786 Only the most commonly used ones are described here.
23787 For a full list, and more detailed explanation of each, see the MIT
23788 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
23792 @deftp {Data Type} krb5-realm
23793 @cindex realm, kerberos
23796 This field is a string identifying the name of the realm.
23797 A common convention is to use the fully qualified DNS name of your organization,
23798 converted to upper case.
23800 @item @code{admin-server}
23801 This field is a string identifying the host where the administration server is
23805 This field is a string identifying the key distribution center
23810 @deftp {Data Type} krb5-configuration
23813 @item @code{allow-weak-crypto?} (default: @code{#f})
23814 If this flag is @code{#t} then services which only offer encryption algorithms
23815 known to be weak will be accepted.
23817 @item @code{default-realm} (default: @code{#f})
23818 This field should be a string identifying the default Kerberos
23819 realm for the client.
23820 You should set this field to the name of your Kerberos realm.
23821 If this value is @code{#f}
23822 then a realm must be specified with every Kerberos principal when invoking programs
23823 such as @command{kinit}.
23825 @item @code{realms}
23826 This should be a non-empty list of @code{krb5-realm} objects, which clients may
23828 Normally, one of them will have a @code{name} field matching the @code{default-realm}
23834 @subsubheading PAM krb5 Service
23837 The @code{pam-krb5} service allows for login authentication and password
23838 management via Kerberos.
23839 You will need this service if you want PAM enabled applications to authenticate
23840 users using Kerberos.
23842 @defvr {Scheme Variable} pam-krb5-service-type
23843 A service type for the Kerberos 5 PAM module.
23846 @deftp {Data Type} pam-krb5-configuration
23847 Data type representing the configuration of the Kerberos 5 PAM module.
23848 This type has the following parameters:
23850 @item @code{pam-krb5} (default: @code{pam-krb5})
23851 The pam-krb5 package to use.
23853 @item @code{minimum-uid} (default: @code{1000})
23854 The smallest user ID for which Kerberos authentications should be attempted.
23855 Local accounts with lower values will silently fail to authenticate.
23860 @node LDAP Services
23861 @subsection LDAP Services
23863 @cindex nslcd, LDAP service
23865 The @code{(gnu services authentication)} module provides the
23866 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
23867 server. In addition to configuring the service itself, you may want to add
23868 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
23869 Switch} for detailed information.
23871 Here is a simple operating system declaration with a default configuration of
23872 the @code{nslcd-service-type} and a Name Service Switch configuration that
23873 consults the @code{ldap} name service last:
23876 (use-service-modules authentication)
23877 (use-modules (gnu system nss))
23883 (service nslcd-service-type)
23884 (service dhcp-client-service-type)
23886 (name-service-switch
23887 (let ((services (list (name-service (name "db"))
23888 (name-service (name "files"))
23889 (name-service (name "ldap")))))
23890 (name-service-switch
23891 (inherit %mdns-host-lookup-nss)
23892 (password services)
23895 (netgroup services)
23896 (gshadow services)))))
23899 @c %start of generated documentation for nslcd-configuration
23901 Available @code{nslcd-configuration} fields are:
23903 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
23904 The @code{nss-pam-ldapd} package to use.
23908 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
23909 The number of threads to start that can handle requests and perform LDAP
23910 queries. Each thread opens a separate connection to the LDAP server.
23911 The default is to start 5 threads.
23913 Defaults to @samp{disabled}.
23917 @deftypevr {@code{nslcd-configuration} parameter} string uid
23918 This specifies the user id with which the daemon should be run.
23920 Defaults to @samp{"nslcd"}.
23924 @deftypevr {@code{nslcd-configuration} parameter} string gid
23925 This specifies the group id with which the daemon should be run.
23927 Defaults to @samp{"nslcd"}.
23931 @deftypevr {@code{nslcd-configuration} parameter} log-option log
23932 This option controls the way logging is done via a list containing
23933 SCHEME and LEVEL@. The SCHEME argument may either be the symbols
23934 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
23935 argument is optional and specifies the log level. The log level may be
23936 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
23937 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
23938 specified log level or higher are logged.
23940 Defaults to @samp{("/var/log/nslcd" info)}.
23944 @deftypevr {@code{nslcd-configuration} parameter} list uri
23945 The list of LDAP server URIs. Normally, only the first server will be
23946 used with the following servers as fall-back.
23948 Defaults to @samp{("ldap://localhost:389/")}.
23952 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
23953 The version of the LDAP protocol to use. The default is to use the
23954 maximum version supported by the LDAP library.
23956 Defaults to @samp{disabled}.
23960 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
23961 Specifies the distinguished name with which to bind to the directory
23962 server for lookups. The default is to bind anonymously.
23964 Defaults to @samp{disabled}.
23968 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
23969 Specifies the credentials with which to bind. This option is only
23970 applicable when used with binddn.
23972 Defaults to @samp{disabled}.
23976 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
23977 Specifies the distinguished name to use when the root user tries to
23978 modify a user's password using the PAM module.
23980 Defaults to @samp{disabled}.
23984 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
23985 Specifies the credentials with which to bind if the root user tries to
23986 change a user's password. This option is only applicable when used with
23989 Defaults to @samp{disabled}.
23993 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
23994 Specifies the SASL mechanism to be used when performing SASL
23997 Defaults to @samp{disabled}.
24001 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
24002 Specifies the SASL realm to be used when performing SASL authentication.
24004 Defaults to @samp{disabled}.
24008 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
24009 Specifies the authentication identity to be used when performing SASL
24012 Defaults to @samp{disabled}.
24016 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
24017 Specifies the authorization identity to be used when performing SASL
24020 Defaults to @samp{disabled}.
24024 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
24025 Determines whether the LDAP server host name should be canonicalised. If
24026 this is enabled the LDAP library will do a reverse host name lookup. By
24027 default, it is left up to the LDAP library whether this check is
24030 Defaults to @samp{disabled}.
24034 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
24035 Set the name for the GSS-API Kerberos credentials cache.
24037 Defaults to @samp{disabled}.
24041 @deftypevr {@code{nslcd-configuration} parameter} string base
24042 The directory search base.
24044 Defaults to @samp{"dc=example,dc=com"}.
24048 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
24049 Specifies the search scope (subtree, onelevel, base or children). The
24050 default scope is subtree; base scope is almost never useful for name
24051 service lookups; children scope is not supported on all servers.
24053 Defaults to @samp{(subtree)}.
24057 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
24058 Specifies the policy for dereferencing aliases. The default policy is
24059 to never dereference aliases.
24061 Defaults to @samp{disabled}.
24065 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
24066 Specifies whether automatic referral chasing should be enabled. The
24067 default behaviour is to chase referrals.
24069 Defaults to @samp{disabled}.
24073 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
24074 This option allows for custom attributes to be looked up instead of the
24075 default RFC 2307 attributes. It is a list of maps, each consisting of
24076 the name of a map, the RFC 2307 attribute to match and the query
24077 expression for the attribute as it is available in the directory.
24079 Defaults to @samp{()}.
24083 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
24084 A list of filters consisting of the name of a map to which the filter
24085 applies and an LDAP search filter expression.
24087 Defaults to @samp{()}.
24091 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
24092 Specifies the time limit in seconds to use when connecting to the
24093 directory server. The default value is 10 seconds.
24095 Defaults to @samp{disabled}.
24099 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
24100 Specifies the time limit (in seconds) to wait for a response from the
24101 LDAP server. A value of zero, which is the default, is to wait
24102 indefinitely for searches to be completed.
24104 Defaults to @samp{disabled}.
24108 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
24109 Specifies the period if inactivity (in seconds) after which the con‐
24110 nection to the LDAP server will be closed. The default is not to time
24113 Defaults to @samp{disabled}.
24117 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
24118 Specifies the number of seconds to sleep when connecting to all LDAP
24119 servers fails. By default one second is waited between the first
24120 failure and the first retry.
24122 Defaults to @samp{disabled}.
24126 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
24127 Specifies the time after which the LDAP server is considered to be
24128 permanently unavailable. Once this time is reached retries will be done
24129 only once per this time period. The default value is 10 seconds.
24131 Defaults to @samp{disabled}.
24135 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
24136 Specifies whether to use SSL/TLS or not (the default is not to). If
24137 'start-tls is specified then StartTLS is used rather than raw LDAP over
24140 Defaults to @samp{disabled}.
24144 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
24145 Specifies what checks to perform on a server-supplied certificate. The
24146 meaning of the values is described in the ldap.conf(5) manual page.
24148 Defaults to @samp{disabled}.
24152 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
24153 Specifies the directory containing X.509 certificates for peer authen‐
24154 tication. This parameter is ignored when using GnuTLS.
24156 Defaults to @samp{disabled}.
24160 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
24161 Specifies the path to the X.509 certificate for peer authentication.
24163 Defaults to @samp{disabled}.
24167 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
24168 Specifies the path to an entropy source. This parameter is ignored when
24171 Defaults to @samp{disabled}.
24175 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
24176 Specifies the ciphers to use for TLS as a string.
24178 Defaults to @samp{disabled}.
24182 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
24183 Specifies the path to the file containing the local certificate for
24184 client TLS authentication.
24186 Defaults to @samp{disabled}.
24190 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
24191 Specifies the path to the file containing the private key for client TLS
24194 Defaults to @samp{disabled}.
24198 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
24199 Set this to a number greater than 0 to request paged results from the
24200 LDAP server in accordance with RFC2696. The default (0) is to not
24201 request paged results.
24203 Defaults to @samp{disabled}.
24207 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
24208 This option prevents group membership lookups through LDAP for the
24209 specified users. Alternatively, the value 'all-local may be used. With
24210 that value nslcd builds a full list of non-LDAP users on startup.
24212 Defaults to @samp{disabled}.
24216 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
24217 This option ensures that LDAP users with a numeric user id lower than
24218 the specified value are ignored.
24220 Defaults to @samp{disabled}.
24224 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
24225 This option specifies an offset that is added to all LDAP numeric user
24226 ids. This can be used to avoid user id collisions with local users.
24228 Defaults to @samp{disabled}.
24232 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
24233 This option specifies an offset that is added to all LDAP numeric group
24234 ids. This can be used to avoid user id collisions with local groups.
24236 Defaults to @samp{disabled}.
24240 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
24241 If this option is set, the member attribute of a group may point to
24242 another group. Members of nested groups are also returned in the higher
24243 level group and parent groups are returned when finding groups for a
24244 specific user. The default is not to perform extra searches for nested
24247 Defaults to @samp{disabled}.
24251 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
24252 If this option is set, the group member list is not retrieved when
24253 looking up groups. Lookups for finding which groups a user belongs to
24254 will remain functional so the user will likely still get the correct
24255 groups assigned on login.
24257 Defaults to @samp{disabled}.
24261 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
24262 If this option is set, functions which cause all user/group entries to
24263 be loaded from the directory will not succeed in doing so. This can
24264 dramatically reduce LDAP server load in situations where there are a
24265 great number of users and/or groups. This option is not recommended for
24266 most configurations.
24268 Defaults to @samp{disabled}.
24272 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
24273 This option can be used to specify how user and group names are verified
24274 within the system. This pattern is used to check all user and group
24275 names that are requested and returned from LDAP.
24277 Defaults to @samp{disabled}.
24281 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
24282 This specifies whether or not to perform searches using case-insensitive
24283 matching. Enabling this could open up the system to authorization
24284 bypass vulnerabilities and introduce nscd cache poisoning
24285 vulnerabilities which allow denial of service.
24287 Defaults to @samp{disabled}.
24291 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
24292 This option specifies whether password policy controls are requested and
24293 handled from the LDAP server when performing user authentication.
24295 Defaults to @samp{disabled}.
24299 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
24300 By default nslcd performs an LDAP search with the user's credentials
24301 after BIND (authentication) to ensure that the BIND operation was
24302 successful. The default search is a simple check to see if the user's
24303 DN exists. A search filter can be specified that will be used instead.
24304 It should return at least one entry.
24306 Defaults to @samp{disabled}.
24310 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
24311 This option allows flexible fine tuning of the authorisation check that
24312 should be performed. The search filter specified is executed and if any
24313 entries match, access is granted, otherwise access is denied.
24315 Defaults to @samp{disabled}.
24319 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
24320 If this option is set password modification using pam_ldap will be
24321 denied and the specified message will be presented to the user instead.
24322 The message can be used to direct the user to an alternative means of
24323 changing their password.
24325 Defaults to @samp{disabled}.
24329 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
24330 List of pam service names for which LDAP authentication should suffice.
24332 Defaults to @samp{()}.
24336 @c %end of generated documentation for nslcd-configuration
24340 @subsection Web Services
24345 The @code{(gnu services web)} module provides the Apache HTTP Server,
24346 the nginx web server, and also a fastcgi wrapper daemon.
24348 @subsubheading Apache HTTP Server
24350 @deffn {Scheme Variable} httpd-service-type
24351 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
24352 (@dfn{httpd}). The value for this service type is a
24353 @code{httpd-configuration} record.
24355 A simple example configuration is given below.
24358 (service httpd-service-type
24359 (httpd-configuration
24362 (server-name "www.example.com")
24363 (document-root "/srv/http/www.example.com")))))
24366 Other services can also extend the @code{httpd-service-type} to add to
24370 (simple-service 'www.example.com-server httpd-service-type
24374 (list (string-join '("ServerName www.example.com"
24375 "DocumentRoot /srv/http/www.example.com")
24380 The details for the @code{httpd-configuration}, @code{httpd-module},
24381 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
24384 @deffn {Data Type} httpd-configuration
24385 This data type represents the configuration for the httpd service.
24388 @item @code{package} (default: @code{httpd})
24389 The httpd package to use.
24391 @item @code{pid-file} (default: @code{"/var/run/httpd"})
24392 The pid file used by the shepherd-service.
24394 @item @code{config} (default: @code{(httpd-config-file)})
24395 The configuration file to use with the httpd service. The default value
24396 is a @code{httpd-config-file} record, but this can also be a different
24397 G-expression that generates a file, for example a @code{plain-file}. A
24398 file outside of the store can also be specified through a string.
24403 @deffn {Data Type} httpd-module
24404 This data type represents a module for the httpd service.
24408 The name of the module.
24411 The file for the module. This can be relative to the httpd package being
24412 used, the absolute location of a file, or a G-expression for a file
24413 within the store, for example @code{(file-append mod-wsgi
24414 "/modules/mod_wsgi.so")}.
24419 @defvr {Scheme Variable} %default-httpd-modules
24420 A default list of @code{httpd-module} objects.
24423 @deffn {Data Type} httpd-config-file
24424 This data type represents a configuration file for the httpd service.
24427 @item @code{modules} (default: @code{%default-httpd-modules})
24428 The modules to load. Additional modules can be added here, or loaded by
24429 additional configuration.
24431 For example, in order to handle requests for PHP files, you can use Apache’s
24432 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
24435 (service httpd-service-type
24436 (httpd-configuration
24441 (name "proxy_module")
24442 (file "modules/mod_proxy.so"))
24444 (name "proxy_fcgi_module")
24445 (file "modules/mod_proxy_fcgi.so"))
24446 %default-httpd-modules))
24447 (extra-config (list "\
24448 <FilesMatch \\.php$>
24449 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
24450 </FilesMatch>"))))))
24451 (service php-fpm-service-type
24452 (php-fpm-configuration
24453 (socket "/var/run/php-fpm.sock")
24454 (socket-group "httpd")))
24457 @item @code{server-root} (default: @code{httpd})
24458 The @code{ServerRoot} in the configuration file, defaults to the httpd
24459 package. Directives including @code{Include} and @code{LoadModule} are
24460 taken as relative to the server root.
24462 @item @code{server-name} (default: @code{#f})
24463 The @code{ServerName} in the configuration file, used to specify the
24464 request scheme, hostname and port that the server uses to identify
24467 This doesn't need to be set in the server config, and can be specified
24468 in virtual hosts. The default is @code{#f} to not specify a
24471 @item @code{document-root} (default: @code{"/srv/http"})
24472 The @code{DocumentRoot} from which files will be served.
24474 @item @code{listen} (default: @code{'("80")})
24475 The list of values for the @code{Listen} directives in the config
24476 file. The value should be a list of strings, when each string can
24477 specify the port number to listen on, and optionally the IP address and
24480 @item @code{pid-file} (default: @code{"/var/run/httpd"})
24481 The @code{PidFile} to use. This should match the @code{pid-file} set in
24482 the @code{httpd-configuration} so that the Shepherd service is
24483 configured correctly.
24485 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
24486 The @code{ErrorLog} to which the server will log errors.
24488 @item @code{user} (default: @code{"httpd"})
24489 The @code{User} which the server will answer requests as.
24491 @item @code{group} (default: @code{"httpd"})
24492 The @code{Group} which the server will answer requests as.
24494 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
24495 A flat list of strings and G-expressions which will be added to the end
24496 of the configuration file.
24498 Any values which the service is extended with will be appended to this
24504 @deffn {Data Type} httpd-virtualhost
24505 This data type represents a virtualhost configuration block for the httpd service.
24507 These should be added to the extra-config for the httpd-service.
24510 (simple-service 'www.example.com-server httpd-service-type
24514 (list (string-join '("ServerName www.example.com"
24515 "DocumentRoot /srv/http/www.example.com")
24520 @item @code{addresses-and-ports}
24521 The addresses and ports for the @code{VirtualHost} directive.
24523 @item @code{contents}
24524 The contents of the @code{VirtualHost} directive, this should be a list
24525 of strings and G-expressions.
24530 @subsubheading NGINX
24532 @deffn {Scheme Variable} nginx-service-type
24533 Service type for the @uref{https://nginx.org/,NGinx} web server. The
24534 value for this service type is a @code{<nginx-configuration>} record.
24536 A simple example configuration is given below.
24539 (service nginx-service-type
24540 (nginx-configuration
24542 (list (nginx-server-configuration
24543 (server-name '("www.example.com"))
24544 (root "/srv/http/www.example.com"))))))
24547 In addition to adding server blocks to the service configuration
24548 directly, this service can be extended by other services to add server
24549 blocks, as in this example:
24552 (simple-service 'my-extra-server nginx-service-type
24553 (list (nginx-server-configuration
24554 (root "/srv/http/extra-website")
24555 (try-files (list "$uri" "$uri/index.html")))))
24559 At startup, @command{nginx} has not yet read its configuration file, so
24560 it uses a default file to log error messages. If it fails to load its
24561 configuration file, that is where error messages are logged. After the
24562 configuration file is loaded, the default error log file changes as per
24563 configuration. In our case, startup error messages can be found in
24564 @file{/var/run/nginx/logs/error.log}, and after configuration in
24565 @file{/var/log/nginx/error.log}. The second location can be changed
24566 with the @var{log-directory} configuration option.
24568 @deffn {Data Type} nginx-configuration
24569 This data type represents the configuration for NGinx. Some
24570 configuration can be done through this and the other provided record
24571 types, or alternatively, a config file can be provided.
24574 @item @code{nginx} (default: @code{nginx})
24575 The nginx package to use.
24577 @item @code{log-directory} (default: @code{"/var/log/nginx"})
24578 The directory to which NGinx will write log files.
24580 @item @code{run-directory} (default: @code{"/var/run/nginx"})
24581 The directory in which NGinx will create a pid file, and write temporary
24584 @item @code{server-blocks} (default: @code{'()})
24585 A list of @dfn{server blocks} to create in the generated configuration
24586 file, the elements should be of type
24587 @code{<nginx-server-configuration>}.
24589 The following example would setup NGinx to serve @code{www.example.com}
24590 from the @code{/srv/http/www.example.com} directory, without using
24593 (service nginx-service-type
24594 (nginx-configuration
24596 (list (nginx-server-configuration
24597 (server-name '("www.example.com"))
24598 (root "/srv/http/www.example.com"))))))
24601 @item @code{upstream-blocks} (default: @code{'()})
24602 A list of @dfn{upstream blocks} to create in the generated configuration
24603 file, the elements should be of type
24604 @code{<nginx-upstream-configuration>}.
24606 Configuring upstreams through the @code{upstream-blocks} can be useful
24607 when combined with @code{locations} in the
24608 @code{<nginx-server-configuration>} records. The following example
24609 creates a server configuration with one location configuration, that
24610 will proxy requests to a upstream configuration, which will handle
24611 requests with two servers.
24616 (nginx-configuration
24618 (list (nginx-server-configuration
24619 (server-name '("www.example.com"))
24620 (root "/srv/http/www.example.com")
24623 (nginx-location-configuration
24625 (body '("proxy_pass http://server-proxy;"))))))))
24627 (list (nginx-upstream-configuration
24628 (name "server-proxy")
24629 (servers (list "server1.example.com"
24630 "server2.example.com")))))))
24633 @item @code{file} (default: @code{#f})
24634 If a configuration @var{file} is provided, this will be used, rather than
24635 generating a configuration file from the provided @code{log-directory},
24636 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
24637 proper operation, these arguments should match what is in @var{file} to ensure
24638 that the directories are created when the service is activated.
24640 This can be useful if you have an existing configuration file, or it's
24641 not possible to do what is required through the other parts of the
24642 nginx-configuration record.
24644 @item @code{server-names-hash-bucket-size} (default: @code{#f})
24645 Bucket size for the server names hash tables, defaults to @code{#f} to
24646 use the size of the processors cache line.
24648 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
24649 Maximum bucket size for the server names hash tables.
24651 @item @code{modules} (default: @code{'()})
24652 List of nginx dynamic modules to load. This should be a list of file
24653 names of loadable modules, as in this example:
24658 (file-append nginx-accept-language-module "\
24659 /etc/nginx/modules/ngx_http_accept_language_module.so")
24660 (file-append nginx-lua-module "\
24661 /etc/nginx/modules/ngx_http_lua_module.so")))
24664 @item @code{lua-package-path} (default: @code{'()})
24665 List of nginx lua packages to load. This should be a list of package
24666 names of loadable lua modules, as in this example:
24669 (lua-package-path (list lua-resty-core
24676 @item @code{lua-package-cpath} (default: @code{'()})
24677 List of nginx lua C packages to load. This should be a list of package
24678 names of loadable lua C modules, as in this example:
24681 (lua-package-cpath (list lua-resty-signal))
24684 @item @code{global-directives} (default: @code{'((events . ()))})
24685 Association list of global directives for the top level of the nginx
24686 configuration. Values may themselves be association lists.
24690 `((worker_processes . 16)
24692 (events . ((worker_connections . 1024)))))
24695 @item @code{extra-content} (default: @code{""})
24696 Extra content for the @code{http} block. Should be string or a string
24697 valued G-expression.
24702 @deftp {Data Type} nginx-server-configuration
24703 Data type representing the configuration of an nginx server block.
24704 This type has the following parameters:
24707 @item @code{listen} (default: @code{'("80" "443 ssl")})
24708 Each @code{listen} directive sets the address and port for IP, or the
24709 path for a UNIX-domain socket on which the server will accept requests.
24710 Both address and port, or only address or only port can be specified.
24711 An address may also be a hostname, for example:
24714 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
24717 @item @code{server-name} (default: @code{(list 'default)})
24718 A list of server names this server represents. @code{'default} represents the
24719 default server for connections matching no other server.
24721 @item @code{root} (default: @code{"/srv/http"})
24722 Root of the website nginx will serve.
24724 @item @code{locations} (default: @code{'()})
24725 A list of @dfn{nginx-location-configuration} or
24726 @dfn{nginx-named-location-configuration} records to use within this
24729 @item @code{index} (default: @code{(list "index.html")})
24730 Index files to look for when clients ask for a directory. If it cannot be found,
24731 Nginx will send the list of files in the directory.
24733 @item @code{try-files} (default: @code{'()})
24734 A list of files whose existence is checked in the specified order.
24735 @code{nginx} will use the first file it finds to process the request.
24737 @item @code{ssl-certificate} (default: @code{#f})
24738 Where to find the certificate for secure connections. Set it to @code{#f} if
24739 you don't have a certificate or you don't want to use HTTPS.
24741 @item @code{ssl-certificate-key} (default: @code{#f})
24742 Where to find the private key for secure connections. Set it to @code{#f} if
24743 you don't have a key or you don't want to use HTTPS.
24745 @item @code{server-tokens?} (default: @code{#f})
24746 Whether the server should add its configuration to response.
24748 @item @code{raw-content} (default: @code{'()})
24749 A list of raw lines added to the server block.
24754 @deftp {Data Type} nginx-upstream-configuration
24755 Data type representing the configuration of an nginx @code{upstream}
24756 block. This type has the following parameters:
24760 Name for this group of servers.
24762 @item @code{servers}
24763 Specify the addresses of the servers in the group. The address can be
24764 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
24765 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
24766 prefix @samp{unix:}. For addresses using an IP address or domain name,
24767 the default port is 80, and a different port can be specified
24773 @deftp {Data Type} nginx-location-configuration
24774 Data type representing the configuration of an nginx @code{location}
24775 block. This type has the following parameters:
24779 URI which this location block matches.
24781 @anchor{nginx-location-configuration body}
24783 Body of the location block, specified as a list of strings. This can contain
24785 configuration directives. For example, to pass requests to a upstream
24786 server group defined using an @code{nginx-upstream-configuration} block,
24787 the following directive would be specified in the body @samp{(list "proxy_pass
24788 http://upstream-name;")}.
24793 @deftp {Data Type} nginx-named-location-configuration
24794 Data type representing the configuration of an nginx named location
24795 block. Named location blocks are used for request redirection, and not
24796 used for regular request processing. This type has the following
24801 Name to identify this location block.
24804 @xref{nginx-location-configuration body}, as the body for named location
24805 blocks can be used in a similar way to the
24806 @code{nginx-location-configuration body}. One restriction is that the
24807 body of a named location block cannot contain location blocks.
24812 @subsubheading Varnish Cache
24814 Varnish is a fast cache server that sits in between web applications
24815 and end users. It proxies requests from clients and caches the
24816 accessed URLs such that multiple requests for the same resource only
24817 creates one request to the back-end.
24819 @defvr {Scheme Variable} varnish-service-type
24820 Service type for the Varnish daemon.
24823 @deftp {Data Type} varnish-configuration
24824 Data type representing the @code{varnish} service configuration.
24825 This type has the following parameters:
24828 @item @code{package} (default: @code{varnish})
24829 The Varnish package to use.
24831 @item @code{name} (default: @code{"default"})
24832 A name for this Varnish instance. Varnish will create a directory in
24833 @file{/var/varnish/} with this name and keep temporary files there. If
24834 the name starts with a forward slash, it is interpreted as an absolute
24837 Pass the @code{-n} argument to other Varnish programs to connect to the
24838 named instance, e.g.@: @command{varnishncsa -n default}.
24840 @item @code{backend} (default: @code{"localhost:8080"})
24841 The backend to use. This option has no effect if @code{vcl} is set.
24843 @item @code{vcl} (default: #f)
24844 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
24845 is @code{#f}, Varnish will proxy @code{backend} using the default
24846 configuration. Otherwise this must be a file-like object with valid
24849 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
24850 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
24851 can do something along these lines:
24854 (define %gnu-mirror
24855 (plain-file "gnu.vcl"
24857 backend gnu @{ .host = \"www.gnu.org\"; @}"))
24861 (services (cons (service varnish-service-type
24862 (varnish-configuration
24864 (vcl %gnu-mirror)))
24868 The configuration of an already running Varnish instance can be inspected
24869 and changed using the @command{varnishadm} program.
24871 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
24872 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
24873 comprehensive documentation on Varnish and its configuration language.
24875 @item @code{listen} (default: @code{'("localhost:80")})
24876 List of addresses Varnish will listen on.
24878 @item @code{storage} (default: @code{'("malloc,128m")})
24879 List of storage backends that will be available in VCL.
24881 @item @code{parameters} (default: @code{'()})
24882 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
24884 @item @code{extra-options} (default: @code{'()})
24885 Additional arguments to pass to the @command{varnishd} process.
24890 @subsubheading Patchwork
24892 Patchwork is a patch tracking system. It can collect patches sent to a
24893 mailing list, and display them in a web interface.
24895 @defvr {Scheme Variable} patchwork-service-type
24896 Service type for Patchwork.
24899 The following example is an example of a minimal service for Patchwork, for
24900 the @code{patchwork.example.com} domain.
24903 (service patchwork-service-type
24904 (patchwork-configuration
24905 (domain "patchwork.example.com")
24907 (patchwork-settings-module
24908 (allowed-hosts (list domain))
24909 (default-from-email "patchwork@@patchwork.example.com")))
24910 (getmail-retriever-config
24911 (getmail-retriever-configuration
24912 (type "SimpleIMAPSSLRetriever")
24913 (server "imap.example.com")
24915 (username "patchwork")
24917 (list (file-append coreutils "/bin/cat")
24918 "/etc/getmail-patchwork-imap-password"))
24920 '((mailboxes . ("Patches"))))))))
24924 There are three records for configuring the Patchwork service. The
24925 @code{<patchwork-configuration>} relates to the configuration for Patchwork
24926 within the HTTPD service.
24928 The @code{settings-module} field within the @code{<patchwork-configuration>}
24929 record can be populated with the @code{<patchwork-settings-module>} record,
24930 which describes a settings module that is generated within the Guix store.
24932 For the @code{database-configuration} field within the
24933 @code{<patchwork-settings-module>}, the
24934 @code{<patchwork-database-configuration>} must be used.
24936 @deftp {Data Type} patchwork-configuration
24937 Data type representing the Patchwork service configuration. This type has the
24938 following parameters:
24941 @item @code{patchwork} (default: @code{patchwork})
24942 The Patchwork package to use.
24944 @item @code{domain}
24945 The domain to use for Patchwork, this is used in the HTTPD service virtual
24948 @item @code{settings-module}
24949 The settings module to use for Patchwork. As a Django application, Patchwork
24950 is configured with a Python module containing the settings. This can either be
24951 an instance of the @code{<patchwork-settings-module>} record, any other record
24952 that represents the settings in the store, or a directory outside of the
24955 @item @code{static-path} (default: @code{"/static/"})
24956 The path under which the HTTPD service should serve the static files.
24958 @item @code{getmail-retriever-config}
24959 The getmail-retriever-configuration record value to use with
24960 Patchwork. Getmail will be configured with this value, the messages will be
24961 delivered to Patchwork.
24966 @deftp {Data Type} patchwork-settings-module
24967 Data type representing a settings module for Patchwork. Some of these
24968 settings relate directly to Patchwork, but others relate to Django, the web
24969 framework used by Patchwork, or the Django Rest Framework library. This type
24970 has the following parameters:
24973 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
24974 The database connection settings used for Patchwork. See the
24975 @code{<patchwork-database-configuration>} record type for more information.
24977 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
24978 Patchwork, as a Django web application uses a secret key for cryptographically
24979 signing values. This file should contain a unique unpredictable value.
24981 If this file does not exist, it will be created and populated with a random
24982 value by the patchwork-setup shepherd service.
24984 This setting relates to Django.
24986 @item @code{allowed-hosts}
24987 A list of valid hosts for this Patchwork service. This should at least include
24988 the domain specified in the @code{<patchwork-configuration>} record.
24990 This is a Django setting.
24992 @item @code{default-from-email}
24993 The email address from which Patchwork should send email by default.
24995 This is a Patchwork setting.
24997 @item @code{static-url} (default: @code{#f})
24998 The URL to use when serving static assets. It can be part of a URL, or a full
24999 URL, but must end in a @code{/}.
25001 If the default value is used, the @code{static-path} value from the
25002 @code{<patchwork-configuration>} record will be used.
25004 This is a Django setting.
25006 @item @code{admins} (default: @code{'()})
25007 Email addresses to send the details of errors that occur. Each value should
25008 be a list containing two elements, the name and then the email address.
25010 This is a Django setting.
25012 @item @code{debug?} (default: @code{#f})
25013 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
25014 messages will be shown.
25016 This is a Django setting.
25018 @item @code{enable-rest-api?} (default: @code{#t})
25019 Whether to enable the Patchwork REST API.
25021 This is a Patchwork setting.
25023 @item @code{enable-xmlrpc?} (default: @code{#t})
25024 Whether to enable the XML RPC API.
25026 This is a Patchwork setting.
25028 @item @code{force-https-links?} (default: @code{#t})
25029 Whether to use HTTPS links on Patchwork pages.
25031 This is a Patchwork setting.
25033 @item @code{extra-settings} (default: @code{""})
25034 Extra code to place at the end of the Patchwork settings module.
25039 @deftp {Data Type} patchwork-database-configuration
25040 Data type representing the database configuration for Patchwork.
25043 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
25044 The database engine to use.
25046 @item @code{name} (default: @code{"patchwork"})
25047 The name of the database to use.
25049 @item @code{user} (default: @code{"httpd"})
25050 The user to connect to the database as.
25052 @item @code{password} (default: @code{""})
25053 The password to use when connecting to the database.
25055 @item @code{host} (default: @code{""})
25056 The host to make the database connection to.
25058 @item @code{port} (default: @code{""})
25059 The port on which to connect to the database.
25064 @subsubheading Mumi
25066 @cindex Mumi, Debbugs Web interface
25067 @cindex Debbugs, Mumi Web interface
25068 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
25069 Web interface to the Debbugs bug tracker, by default for
25070 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
25071 but it also fetches and indexes mail retrieved from Debbugs.
25073 @defvr {Scheme Variable} mumi-service-type
25074 This is the service type for Mumi.
25077 @deftp {Data Type} mumi-configuration
25078 Data type representing the Mumi service configuration. This type has the
25082 @item @code{mumi} (default: @code{mumi})
25083 The Mumi package to use.
25085 @item @code{mailer?} (default: @code{#true})
25086 Whether to enable or disable the mailer component.
25088 @item @code{mumi-configuration-sender}
25089 The email address used as the sender for comments.
25091 @item @code{mumi-configuration-smtp}
25092 A URI to configure the SMTP settings for Mailutils. This could be
25093 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
25094 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
25095 mailutils, GNU@tie{}Mailutils}.
25101 @subsubheading FastCGI
25104 FastCGI is an interface between the front-end and the back-end of a web
25105 service. It is a somewhat legacy facility; new web services should
25106 generally just talk HTTP between the front-end and the back-end.
25107 However there are a number of back-end services such as PHP or the
25108 optimized HTTP Git repository access that use FastCGI, so we have
25109 support for it in Guix.
25111 To use FastCGI, you configure the front-end web server (e.g., nginx) to
25112 dispatch some subset of its requests to the fastcgi backend, which
25113 listens on a local TCP or UNIX socket. There is an intermediary
25114 @code{fcgiwrap} program that sits between the actual backend process and
25115 the web server. The front-end indicates which backend program to run,
25116 passing that information to the @code{fcgiwrap} process.
25118 @defvr {Scheme Variable} fcgiwrap-service-type
25119 A service type for the @code{fcgiwrap} FastCGI proxy.
25122 @deftp {Data Type} fcgiwrap-configuration
25123 Data type representing the configuration of the @code{fcgiwrap} service.
25124 This type has the following parameters:
25126 @item @code{package} (default: @code{fcgiwrap})
25127 The fcgiwrap package to use.
25129 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
25130 The socket on which the @code{fcgiwrap} process should listen, as a
25131 string. Valid @var{socket} values include
25132 @code{unix:@var{/path/to/unix/socket}},
25133 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
25134 @code{tcp6:[@var{ipv6_addr}]:port}.
25136 @item @code{user} (default: @code{fcgiwrap})
25137 @itemx @code{group} (default: @code{fcgiwrap})
25138 The user and group names, as strings, under which to run the
25139 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
25140 the user asks for the specific user or group names @code{fcgiwrap} that
25141 the corresponding user and/or group is present on the system.
25143 It is possible to configure a FastCGI-backed web service to pass HTTP
25144 authentication information from the front-end to the back-end, and to
25145 allow @code{fcgiwrap} to run the back-end process as a corresponding
25146 local user. To enable this capability on the back-end, run
25147 @code{fcgiwrap} as the @code{root} user and group. Note that this
25148 capability also has to be configured on the front-end as well.
25153 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
25154 with some additional features useful for sites of any size.
25156 These features include:
25158 @item Adaptive process spawning
25159 @item Basic statistics (similar to Apache's mod_status)
25160 @item Advanced process management with graceful stop/start
25161 @item Ability to start workers with different uid/gid/chroot/environment
25162 and different php.ini (replaces safe_mode)
25163 @item Stdout & stderr logging
25164 @item Emergency restart in case of accidental opcode cache destruction
25165 @item Accelerated upload support
25166 @item Support for a "slowlog"
25167 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
25168 a special function to finish request & flush all data while continuing to do
25169 something time-consuming (video converting, stats processing, etc.)
25171 ...@: and much more.
25173 @defvr {Scheme Variable} php-fpm-service-type
25174 A Service type for @code{php-fpm}.
25177 @deftp {Data Type} php-fpm-configuration
25178 Data Type for php-fpm service configuration.
25180 @item @code{php} (default: @code{php})
25181 The php package to use.
25182 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
25183 The address on which to accept FastCGI requests. Valid syntaxes are:
25185 @item @code{"ip.add.re.ss:port"}
25186 Listen on a TCP socket to a specific address on a specific port.
25187 @item @code{"port"}
25188 Listen on a TCP socket to all addresses on a specific port.
25189 @item @code{"/path/to/unix/socket"}
25190 Listen on a unix socket.
25193 @item @code{user} (default: @code{php-fpm})
25194 User who will own the php worker processes.
25195 @item @code{group} (default: @code{php-fpm})
25196 Group of the worker processes.
25197 @item @code{socket-user} (default: @code{php-fpm})
25198 User who can speak to the php-fpm socket.
25199 @item @code{socket-group} (default: @code{nginx})
25200 Group that can speak to the php-fpm socket.
25201 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
25202 The process id of the php-fpm process is written to this file
25203 once the service has started.
25204 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
25205 Log for the php-fpm master process.
25206 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
25207 Detailed settings for the php-fpm process manager.
25210 @item @code{<php-fpm-dynamic-process-manager-configuration>}
25211 @item @code{<php-fpm-static-process-manager-configuration>}
25212 @item @code{<php-fpm-on-demand-process-manager-configuration>}
25214 @item @code{display-errors} (default @code{#f})
25215 Determines whether php errors and warning should be sent to clients
25216 and displayed in their browsers.
25217 This is useful for local php development, but a security risk for public sites,
25218 as error messages can reveal passwords and personal data.
25219 @item @code{timezone} (default @code{#f})
25220 Specifies @code{php_admin_value[date.timezone]} parameter.
25221 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
25222 This file will log the @code{stderr} outputs of php worker processes.
25223 Can be set to @code{#f} to disable logging.
25224 @item @code{file} (default @code{#f})
25225 An optional override of the whole configuration.
25226 You can use the @code{mixed-text-file} function or an absolute filepath for it.
25227 @item @code{php-ini-file} (default @code{#f})
25228 An optional override of the default php settings.
25229 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
25230 You can use the @code{mixed-text-file} function or an absolute filepath for it.
25232 For local development it is useful to set a higher timeout and memory
25233 limit for spawned php processes. This be accomplished with the
25234 following operating system configuration snippet:
25236 (define %local-php-ini
25237 (plain-file "php.ini"
25239 max_execution_time = 1800"))
25243 (services (cons (service php-fpm-service-type
25244 (php-fpm-configuration
25245 (php-ini-file %local-php-ini)))
25249 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
25250 directives} for comprehensive documentation on the acceptable
25251 @file{php.ini} directives.
25255 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
25256 Data Type for the @code{dynamic} php-fpm process manager. With the
25257 @code{dynamic} process manager, spare worker processes are kept around
25258 based on it's configured limits.
25260 @item @code{max-children} (default: @code{5})
25261 Maximum of worker processes.
25262 @item @code{start-servers} (default: @code{2})
25263 How many worker processes should be started on start-up.
25264 @item @code{min-spare-servers} (default: @code{1})
25265 How many spare worker processes should be kept around at minimum.
25266 @item @code{max-spare-servers} (default: @code{3})
25267 How many spare worker processes should be kept around at maximum.
25271 @deftp {Data type} php-fpm-static-process-manager-configuration
25272 Data Type for the @code{static} php-fpm process manager. With the
25273 @code{static} process manager, an unchanging number of worker processes
25276 @item @code{max-children} (default: @code{5})
25277 Maximum of worker processes.
25281 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
25282 Data Type for the @code{on-demand} php-fpm process manager. With the
25283 @code{on-demand} process manager, worker processes are only created as
25286 @item @code{max-children} (default: @code{5})
25287 Maximum of worker processes.
25288 @item @code{process-idle-timeout} (default: @code{10})
25289 The time in seconds after which a process with no requests is killed.
25294 @deffn {Scheme Procedure} nginx-php-location @
25295 [#:nginx-package nginx] @
25296 [socket (string-append "/var/run/php" @
25297 (version-major (package-version php)) @
25299 A helper function to quickly add php to an @code{nginx-server-configuration}.
25302 A simple services setup for nginx with php can look like this:
25304 (services (cons* (service dhcp-client-service-type)
25305 (service php-fpm-service-type)
25306 (service nginx-service-type
25307 (nginx-server-configuration
25308 (server-name '("example.com"))
25309 (root "/srv/http/")
25311 (list (nginx-php-location)))
25313 (ssl-certificate #f)
25314 (ssl-certificate-key #f)))
25318 @cindex cat-avatar-generator
25319 The cat avatar generator is a simple service to demonstrate the use of php-fpm
25320 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
25321 the hash of a user's email address.
25323 @deffn {Scheme Procedure} cat-avatar-generator-service @
25324 [#:cache-dir "/var/cache/cat-avatar-generator"] @
25325 [#:package cat-avatar-generator] @
25326 [#:configuration (nginx-server-configuration)]
25327 Returns an nginx-server-configuration that inherits @code{configuration}. It
25328 extends the nginx configuration to add a server block that serves @code{package},
25329 a version of cat-avatar-generator. During execution, cat-avatar-generator will
25330 be able to use @code{cache-dir} as its cache directory.
25333 A simple setup for cat-avatar-generator can look like this:
25335 (services (cons* (cat-avatar-generator-service
25337 (nginx-server-configuration
25338 (server-name '("example.com"))))
25343 @subsubheading Hpcguix-web
25345 @cindex hpcguix-web
25346 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
25347 program is a customizable web interface to browse Guix packages,
25348 initially designed for users of high-performance computing (HPC)
25351 @defvr {Scheme Variable} hpcguix-web-service-type
25352 The service type for @code{hpcguix-web}.
25355 @deftp {Data Type} hpcguix-web-configuration
25356 Data type for the hpcguix-web service configuration.
25360 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
25361 configuration. The main items available in this spec are:
25364 @item @code{title-prefix} (default: @code{"hpcguix | "})
25365 The page title prefix.
25367 @item @code{guix-command} (default: @code{"guix"})
25368 The @command{guix} command.
25370 @item @code{package-filter-proc} (default: @code{(const #t)})
25371 A procedure specifying how to filter packages that are displayed.
25373 @item @code{package-page-extension-proc} (default: @code{(const '())})
25374 Extension package for @code{hpcguix-web}.
25376 @item @code{menu} (default: @code{'()})
25377 Additional entry in page @code{menu}.
25379 @item @code{channels} (default: @code{%default-channels})
25380 List of channels from which the package list is built (@pxref{Channels}).
25382 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
25383 The expiration time, in seconds, after which the package list is rebuilt from
25384 the latest instances of the given channels.
25387 See the hpcguix-web repository for a
25388 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
25391 @item @code{package} (default: @code{hpcguix-web})
25392 The hpcguix-web package to use.
25396 A typical hpcguix-web service declaration looks like this:
25399 (service hpcguix-web-service-type
25400 (hpcguix-web-configuration
25402 #~(define site-config
25403 (hpcweb-configuration
25404 (title-prefix "Guix-HPC - ")
25405 (menu '(("/about" "ABOUT"))))))))
25409 The hpcguix-web service periodically updates the package list it publishes by
25410 pulling channels from Git. To that end, it needs to access X.509 certificates
25411 so that it can authenticate Git servers when communicating over HTTPS, and it
25412 assumes that @file{/etc/ssl/certs} contains those certificates.
25414 Thus, make sure to add @code{nss-certs} or another certificate package to the
25415 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
25416 more information on X.509 certificates.
25419 @subsubheading gmnisrv
25422 The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
25423 simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
25425 @deffn {Scheme Variable} gmnisrv-service-type
25426 This is the type of the gmnisrv service, whose value should be a
25427 @code{gmnisrv-configuration} object, as in this example:
25430 (service gmnisrv-service-type
25431 (gmnisrv-configuration
25432 (config-file (local-file "./my-gmnisrv.ini"))))
25436 @deftp {Data Type} gmnisrv-configuration
25437 Data type representing the configuration of gmnisrv.
25440 @item @code{package} (default: @var{gmnisrv})
25441 Package object of the gmnisrv server.
25443 @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
25444 File-like object of the gmnisrv configuration file to use. The default
25445 configuration listens on port 1965 and serves files from
25446 @file{/srv/gemini}. Certificates are stored in
25447 @file{/var/lib/gemini/certs}. For more information, run @command{man
25448 gmnisrv} and @command{man gmnisrv.ini}.
25453 @subsubheading Agate
25456 The @uref{gemini://qwertqwefsday.eu/agate.gmi, Agate}
25457 (@uref{https://github.com/mbrubeck/agate, GitHub page over HTTPS})
25458 program is a simple @uref{https://gemini.circumlunar.space/, Gemini}
25459 protocol server written in Rust.
25461 @deffn {Scheme Variable} agate-service-type
25462 This is the type of the agate service, whose value should be an
25463 @code{agate-service-type} object, as in this example:
25466 (service agate-service-type
25467 (agate-configuration
25468 (content "/srv/gemini")
25469 (cert "/srv/cert.pem")
25470 (key "/srv/key.rsa")))
25473 The example above represents the minimal tweaking necessary to get Agate
25474 up and running. Specifying the path to the certificate and key is
25475 always necessary, as the Gemini protocol requires TLS by default.
25477 To obtain a certificate and a key, you could, for example, use OpenSSL,
25478 running a command similar to the following example:
25481 openssl req -x509 -newkey rsa:4096 -keyout key.rsa -out cert.pem \
25482 -days 3650 -nodes -subj "/CN=example.com"
25485 Of course, you'll have to replace @i{example.com} with your own domain
25486 name, and then point the Agate configuration towards the path of the
25487 generated key and certificate.
25491 @deftp {Data Type} agate-configuration
25492 Data type representing the configuration of Agate.
25495 @item @code{package} (default: @code{agate})
25496 The package object of the Agate server.
25498 @item @code{content} (default: @file{"/srv/gemini"})
25499 The directory from which Agate will serve files.
25501 @item @code{cert} (default: @code{#f})
25502 The path to the TLS certificate PEM file to be used for encrypted
25503 connections. Must be filled in with a value from the user.
25505 @item @code{key} (default: @code{#f})
25506 The path to the PKCS8 private key file to be used for encrypted
25507 connections. Must be filled in with a value from the user.
25509 @item @code{addr} (default: @code{'("0.0.0.0:1965" "[::]:1965")})
25510 A list of the addresses to listen on.
25512 @item @code{hostname} (default: @code{#f})
25513 The domain name of this Gemini server. Optional.
25515 @item @code{lang} (default: @code{#f})
25516 RFC 4646 language code(s) for text/gemini documents. Optional.
25518 @item @code{silent?} (default: @code{#f})
25519 Set to @code{#t} to disable logging output.
25521 @item @code{serve-secret?} (default: @code{#f})
25522 Set to @code{#t} to serve secret files (files/directories starting with
25525 @item @code{log-ip?} (default: @code{#t})
25526 Whether or not to output IP addresses when logging.
25528 @item @code{user} (default: @code{"agate"})
25529 Owner of the @code{agate} process.
25531 @item @code{group} (default: @code{"agate"})
25532 Owner's group of the @code{agate} process.
25534 @item @code{log-file} (default: @file{"/var/log/agate.log"})
25535 The file which should store the logging output of Agate.
25540 @node Certificate Services
25541 @subsection Certificate Services
25544 @cindex HTTP, HTTPS
25545 @cindex Let's Encrypt
25546 @cindex TLS certificates
25547 The @code{(gnu services certbot)} module provides a service to
25548 automatically obtain a valid TLS certificate from the Let's Encrypt
25549 certificate authority. These certificates can then be used to serve
25550 content securely over HTTPS or other TLS-based protocols, with the
25551 knowledge that the client will be able to verify the server's
25554 @url{https://letsencrypt.org/, Let's Encrypt} provides the
25555 @code{certbot} tool to automate the certification process. This tool
25556 first securely generates a key on the server. It then makes a request
25557 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
25558 checks that the request originates from the host in question by using a
25559 challenge-response protocol, requiring the server to provide its
25560 response over HTTP@. If that protocol completes successfully, the CA
25561 signs the key, resulting in a certificate. That certificate is valid
25562 for a limited period of time, and therefore to continue to provide TLS
25563 services, the server needs to periodically ask the CA to renew its
25566 The certbot service automates this process: the initial key
25567 generation, the initial certification request to the Let's Encrypt
25568 service, the web server challenge/response integration, writing the
25569 certificate to disk, the automated periodic renewals, and the deployment
25570 tasks associated with the renewal (e.g.@: reloading services, copying keys
25571 with different permissions).
25573 Certbot is run twice a day, at a random minute within the hour. It
25574 won't do anything until your certificates are due for renewal or
25575 revoked, but running it regularly would give your service a chance of
25576 staying online in case a Let's Encrypt-initiated revocation happened for
25579 By using this service, you agree to the ACME Subscriber Agreement, which
25580 can be found there:
25581 @url{https://acme-v01.api.letsencrypt.org/directory}.
25583 @defvr {Scheme Variable} certbot-service-type
25584 A service type for the @code{certbot} Let's Encrypt client. Its value
25585 must be a @code{certbot-configuration} record as in this example:
25588 (define %nginx-deploy-hook
25590 "nginx-deploy-hook"
25591 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
25592 (kill pid SIGHUP))))
25594 (service certbot-service-type
25595 (certbot-configuration
25596 (email "foo@@example.net")
25599 (certificate-configuration
25600 (domains '("example.net" "www.example.net"))
25601 (deploy-hook %nginx-deploy-hook))
25602 (certificate-configuration
25603 (domains '("bar.example.net")))))))
25606 See below for details about @code{certbot-configuration}.
25609 @deftp {Data Type} certbot-configuration
25610 Data type representing the configuration of the @code{certbot} service.
25611 This type has the following parameters:
25614 @item @code{package} (default: @code{certbot})
25615 The certbot package to use.
25617 @item @code{webroot} (default: @code{/var/www})
25618 The directory from which to serve the Let's Encrypt challenge/response
25621 @item @code{certificates} (default: @code{()})
25622 A list of @code{certificates-configuration}s for which to generate
25623 certificates and request signatures. Each certificate has a @code{name}
25624 and several @code{domains}.
25626 @item @code{email} (default: @code{#f})
25627 Optional email address used for registration and recovery contact.
25628 Setting this is encouraged as it allows you to receive important
25629 notifications about the account and issued certificates.
25631 @item @code{server} (default: @code{#f})
25632 Optional URL of ACME server. Setting this overrides certbot's default,
25633 which is the Let's Encrypt server.
25635 @item @code{rsa-key-size} (default: @code{2048})
25636 Size of the RSA key.
25638 @item @code{default-location} (default: @i{see below})
25639 The default @code{nginx-location-configuration}. Because @code{certbot}
25640 needs to be able to serve challenges and responses, it needs to be able
25641 to run a web server. It does so by extending the @code{nginx} web
25642 service with an @code{nginx-server-configuration} listening on the
25643 @var{domains} on port 80, and which has a
25644 @code{nginx-location-configuration} for the @code{/.well-known/} URI
25645 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
25646 these nginx configuration data types.
25648 Requests to other URL paths will be matched by the
25649 @code{default-location}, which if present is added to all
25650 @code{nginx-server-configuration}s.
25652 By default, the @code{default-location} will issue a redirect from
25653 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
25654 you to define what to serve on your site via @code{https}.
25656 Pass @code{#f} to not issue a default location.
25660 @deftp {Data Type} certificate-configuration
25661 Data type representing the configuration of a certificate.
25662 This type has the following parameters:
25665 @item @code{name} (default: @i{see below})
25666 This name is used by Certbot for housekeeping and in file paths; it
25667 doesn't affect the content of the certificate itself. To see
25668 certificate names, run @code{certbot certificates}.
25670 Its default is the first provided domain.
25672 @item @code{domains} (default: @code{()})
25673 The first domain provided will be the subject CN of the certificate, and
25674 all domains will be Subject Alternative Names on the certificate.
25676 @item @code{challenge} (default: @code{#f})
25677 The challenge type that has to be run by certbot. If @code{#f} is specified,
25678 default to the HTTP challenge. If a value is specified, defaults to the
25679 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
25680 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
25681 and gives Let's Encrypt permission to log the public IP address of the
25682 requesting machine.
25684 @item @code{authentication-hook} (default: @code{#f})
25685 Command to be run in a shell once for each certificate challenge to be
25686 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
25687 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
25688 contains the validation string and @code{$CERTBOT_TOKEN} contains the
25689 file name of the resource requested when performing an HTTP-01 challenge.
25691 @item @code{cleanup-hook} (default: @code{#f})
25692 Command to be run in a shell once for each certificate challenge that
25693 have been answered by the @code{auth-hook}. For this command, the shell
25694 variables available in the @code{auth-hook} script are still available, and
25695 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
25696 of the @code{auth-hook} script.
25698 @item @code{deploy-hook} (default: @code{#f})
25699 Command to be run in a shell once for each successfully issued
25700 certificate. For this command, the shell variable
25701 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
25702 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
25703 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
25704 contain a space-delimited list of renewed certificate domains (for
25705 example, @samp{"example.com www.example.com"}.
25710 For each @code{certificate-configuration}, the certificate is saved to
25711 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
25712 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
25714 @subsection DNS Services
25715 @cindex DNS (domain name system)
25716 @cindex domain name system (DNS)
25718 The @code{(gnu services dns)} module provides services related to the
25719 @dfn{domain name system} (DNS). It provides a server service for hosting
25720 an @emph{authoritative} DNS server for multiple zones, slave or master.
25721 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
25722 caching and forwarding DNS server for the LAN, which uses
25723 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
25725 @subsubheading Knot Service
25727 An example configuration of an authoritative server for two zones, one master
25731 (define-zone-entries example.org.zone
25732 ;; Name TTL Class Type Data
25733 ("@@" "" "IN" "A" "127.0.0.1")
25734 ("@@" "" "IN" "NS" "ns")
25735 ("ns" "" "IN" "A" "127.0.0.1"))
25737 (define master-zone
25738 (knot-zone-configuration
25739 (domain "example.org")
25741 (origin "example.org")
25742 (entries example.org.zone)))))
25745 (knot-zone-configuration
25746 (domain "plop.org")
25747 (dnssec-policy "default")
25748 (master (list "plop-master"))))
25750 (define plop-master
25751 (knot-remote-configuration
25753 (address (list "208.76.58.171"))))
25757 (services (cons* (service knot-service-type
25758 (knot-configuration
25759 (remotes (list plop-master))
25760 (zones (list master-zone slave-zone))))
25765 @deffn {Scheme Variable} knot-service-type
25766 This is the type for the Knot DNS server.
25768 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
25769 zones, that is to say domain names you would buy from a registrar. This server
25770 is not a resolver, meaning that it can only resolve names for which it is
25771 authoritative. This server can be configured to serve zones as a master server
25772 or a slave server as a per-zone basis. Slave zones will get their data from
25773 masters, and will serve it as an authoritative server. From the point of view
25774 of a resolver, there is no difference between master and slave.
25776 The following data types are used to configure the Knot DNS server:
25779 @deftp {Data Type} knot-key-configuration
25780 Data type representing a key.
25781 This type has the following parameters:
25784 @item @code{id} (default: @code{""})
25785 An identifier for other configuration fields to refer to this key. IDs must
25786 be unique and must not be empty.
25788 @item @code{algorithm} (default: @code{#f})
25789 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
25790 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
25791 and @code{'hmac-sha512}.
25793 @item @code{secret} (default: @code{""})
25794 The secret key itself.
25799 @deftp {Data Type} knot-acl-configuration
25800 Data type representing an Access Control List (ACL) configuration.
25801 This type has the following parameters:
25804 @item @code{id} (default: @code{""})
25805 An identifier for other configuration fields to refer to this key. IDs must be
25806 unique and must not be empty.
25808 @item @code{address} (default: @code{'()})
25809 An ordered list of IP addresses, network subnets, or network ranges represented
25810 with strings. The query must match one of them. Empty value means that
25811 address match is not required.
25813 @item @code{key} (default: @code{'()})
25814 An ordered list of references to keys represented with strings. The string
25815 must match a key ID defined in a @code{knot-key-configuration}. No key means
25816 that a key is not require to match that ACL.
25818 @item @code{action} (default: @code{'()})
25819 An ordered list of actions that are permitted or forbidden by this ACL@. Possible
25820 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
25821 and @code{'update}.
25823 @item @code{deny?} (default: @code{#f})
25824 When true, the ACL defines restrictions. Listed actions are forbidden. When
25825 false, listed actions are allowed.
25830 @deftp {Data Type} zone-entry
25831 Data type representing a record entry in a zone file.
25832 This type has the following parameters:
25835 @item @code{name} (default: @code{"@@"})
25836 The name of the record. @code{"@@"} refers to the origin of the zone. Names
25837 are relative to the origin of the zone. For example, in the @code{example.org}
25838 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
25839 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
25840 refers to @code{ns.example.org}.
25842 @item @code{ttl} (default: @code{""})
25843 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
25845 @item @code{class} (default: @code{"IN"})
25846 The class of the record. Knot currently supports only @code{"IN"} and
25847 partially @code{"CH"}.
25849 @item @code{type} (default: @code{"A"})
25850 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
25851 address), NS (Name Server) and MX (Mail eXchange). Many other types are
25854 @item @code{data} (default: @code{""})
25855 The data contained in the record. For instance an IP address associated with
25856 an A record, or a domain name associated with an NS record. Remember that
25857 domain names are relative to the origin unless they end with a dot.
25862 @deftp {Data Type} zone-file
25863 Data type representing the content of a zone file.
25864 This type has the following parameters:
25867 @item @code{entries} (default: @code{'()})
25868 The list of entries. The SOA record is taken care of, so you don't need to
25869 put it in the list of entries. This list should probably contain an entry
25870 for your primary authoritative DNS server. Other than using a list of entries
25871 directly, you can use @code{define-zone-entries} to define a object containing
25872 the list of entries more easily, that you can later pass to the @code{entries}
25873 field of the @code{zone-file}.
25875 @item @code{origin} (default: @code{""})
25876 The name of your zone. This parameter cannot be empty.
25878 @item @code{ns} (default: @code{"ns"})
25879 The domain of your primary authoritative DNS server. The name is relative to
25880 the origin, unless it ends with a dot. It is mandatory that this primary
25881 DNS server corresponds to an NS record in the zone and that it is associated
25882 to an IP address in the list of entries.
25884 @item @code{mail} (default: @code{"hostmaster"})
25885 An email address people can contact you at, as the owner of the zone. This
25886 is translated as @code{<mail>@@<origin>}.
25888 @item @code{serial} (default: @code{1})
25889 The serial number of the zone. As this is used to keep track of changes by
25890 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
25891 Always increment it when you make a change in your zone.
25893 @item @code{refresh} (default: @code{(* 2 24 3600)})
25894 The frequency at which slaves will do a zone transfer. This value is a number
25895 of seconds. It can be computed by multiplications or with
25896 @code{(string->duration)}.
25898 @item @code{retry} (default: @code{(* 15 60)})
25899 The period after which a slave will retry to contact its master when it fails
25900 to do so a first time.
25902 @item @code{expiry} (default: @code{(* 14 24 3600)})
25903 Default TTL of records. Existing records are considered correct for at most
25904 this amount of time. After this period, resolvers will invalidate their cache
25905 and check again that it still exists.
25907 @item @code{nx} (default: @code{3600})
25908 Default TTL of inexistant records. This delay is usually short because you want
25909 your new domains to reach everyone quickly.
25914 @deftp {Data Type} knot-remote-configuration
25915 Data type representing a remote configuration.
25916 This type has the following parameters:
25919 @item @code{id} (default: @code{""})
25920 An identifier for other configuration fields to refer to this remote. IDs must
25921 be unique and must not be empty.
25923 @item @code{address} (default: @code{'()})
25924 An ordered list of destination IP addresses. Addresses are tried in sequence.
25925 An optional port can be given with the @@ separator. For instance:
25926 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
25928 @item @code{via} (default: @code{'()})
25929 An ordered list of source IP addresses. An empty list will have Knot choose
25930 an appropriate source IP@. An optional port can be given with the @@ separator.
25931 The default is to choose at random.
25933 @item @code{key} (default: @code{#f})
25934 A reference to a key, that is a string containing the identifier of a key
25935 defined in a @code{knot-key-configuration} field.
25940 @deftp {Data Type} knot-keystore-configuration
25941 Data type representing a keystore to hold dnssec keys.
25942 This type has the following parameters:
25945 @item @code{id} (default: @code{""})
25946 The id of the keystore. It must not be empty.
25948 @item @code{backend} (default: @code{'pem})
25949 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
25951 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
25952 The configuration string of the backend. An example for the PKCS#11 is:
25953 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
25954 For the pem backend, the string represents a path in the file system.
25959 @deftp {Data Type} knot-policy-configuration
25960 Data type representing a dnssec policy. Knot DNS is able to automatically
25961 sign your zones. It can either generate and manage your keys automatically or
25962 use keys that you generate.
25964 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
25965 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
25966 zone. In order to be trusted, the KSK needs to be present in the parent zone
25967 (usually a top-level domain). If your registrar supports dnssec, you will
25968 have to send them your KSK's hash so they can add a DS record in their zone.
25969 This is not automated and need to be done each time you change your KSK.
25971 The policy also defines the lifetime of keys. Usually, ZSK can be changed
25972 easily and use weaker cryptographic functions (they use lower parameters) in
25973 order to sign records quickly, so they are changed often. The KSK however
25974 requires manual interaction with the registrar, so they are changed less often
25975 and use stronger parameters because they sign only one record.
25977 This type has the following parameters:
25980 @item @code{id} (default: @code{""})
25981 The id of the policy. It must not be empty.
25983 @item @code{keystore} (default: @code{"default"})
25984 A reference to a keystore, that is a string containing the identifier of a
25985 keystore defined in a @code{knot-keystore-configuration} field. The
25986 @code{"default"} identifier means the default keystore (a kasp database that
25987 was setup by this service).
25989 @item @code{manual?} (default: @code{#f})
25990 Whether the key management is manual or automatic.
25992 @item @code{single-type-signing?} (default: @code{#f})
25993 When @code{#t}, use the Single-Type Signing Scheme.
25995 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
25996 An algorithm of signing keys and issued signatures.
25998 @item @code{ksk-size} (default: @code{256})
25999 The length of the KSK@. Note that this value is correct for the default
26000 algorithm, but would be unsecure for other algorithms.
26002 @item @code{zsk-size} (default: @code{256})
26003 The length of the ZSK@. Note that this value is correct for the default
26004 algorithm, but would be unsecure for other algorithms.
26006 @item @code{dnskey-ttl} (default: @code{'default})
26007 The TTL value for DNSKEY records added into zone apex. The special
26008 @code{'default} value means same as the zone SOA TTL.
26010 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
26011 The period between ZSK publication and the next rollover initiation.
26013 @item @code{propagation-delay} (default: @code{(* 24 3600)})
26014 An extra delay added for each key rollover step. This value should be high
26015 enough to cover propagation of data from the master server to all slaves.
26017 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
26018 A validity period of newly issued signatures.
26020 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
26021 A period how long before a signature expiration the signature will be refreshed.
26023 @item @code{nsec3?} (default: @code{#f})
26024 When @code{#t}, NSEC3 will be used instead of NSEC.
26026 @item @code{nsec3-iterations} (default: @code{5})
26027 The number of additional times the hashing is performed.
26029 @item @code{nsec3-salt-length} (default: @code{8})
26030 The length of a salt field in octets, which is appended to the original owner
26031 name before hashing.
26033 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
26034 The validity period of newly issued salt field.
26039 @deftp {Data Type} knot-zone-configuration
26040 Data type representing a zone served by Knot.
26041 This type has the following parameters:
26044 @item @code{domain} (default: @code{""})
26045 The domain served by this configuration. It must not be empty.
26047 @item @code{file} (default: @code{""})
26048 The file where this zone is saved. This parameter is ignored by master zones.
26049 Empty means default location that depends on the domain name.
26051 @item @code{zone} (default: @code{(zone-file)})
26052 The content of the zone file. This parameter is ignored by slave zones. It
26053 must contain a zone-file record.
26055 @item @code{master} (default: @code{'()})
26056 A list of master remotes. When empty, this zone is a master. When set, this
26057 zone is a slave. This is a list of remotes identifiers.
26059 @item @code{ddns-master} (default: @code{#f})
26060 The main master. When empty, it defaults to the first master in the list of
26063 @item @code{notify} (default: @code{'()})
26064 A list of slave remote identifiers.
26066 @item @code{acl} (default: @code{'()})
26067 A list of acl identifiers.
26069 @item @code{semantic-checks?} (default: @code{#f})
26070 When set, this adds more semantic checks to the zone.
26072 @item @code{disable-any?} (default: @code{#f})
26073 When set, this forbids queries of the ANY type.
26075 @item @code{zonefile-sync} (default: @code{0})
26076 The delay between a modification in memory and on disk. 0 means immediate
26079 @item @code{zonefile-load} (default: @code{#f})
26080 The way the zone file contents are applied during zone load. Possible values
26084 @item @code{#f} for using the default value from Knot,
26085 @item @code{'none} for not using the zone file at all,
26086 @item @code{'difference} for computing the difference between already available
26087 contents and zone contents and applying it to the current zone contents,
26088 @item @code{'difference-no-serial} for the same as @code{'difference}, but
26089 ignoring the SOA serial in the zone file, while the server takes care of it
26091 @item @code{'whole} for loading zone contents from the zone file.
26094 @item @code{journal-content} (default: @code{#f})
26095 The way the journal is used to store zone and its changes. Possible values
26096 are @code{'none} to not use it at all, @code{'changes} to store changes and
26097 @code{'all} to store contents. @code{#f} does not set this option, so the
26098 default value from Knot is used.
26100 @item @code{max-journal-usage} (default: @code{#f})
26101 The maximum size for the journal on disk. @code{#f} does not set this option,
26102 so the default value from Knot is used.
26104 @item @code{max-journal-depth} (default: @code{#f})
26105 The maximum size of the history. @code{#f} does not set this option, so the
26106 default value from Knot is used.
26108 @item @code{max-zone-size} (default: @code{#f})
26109 The maximum size of the zone file. This limit is enforced for incoming
26110 transfer and updates. @code{#f} does not set this option, so the default
26111 value from Knot is used.
26113 @item @code{dnssec-policy} (default: @code{#f})
26114 A reference to a @code{knot-policy-configuration} record, or the special
26115 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
26118 @item @code{serial-policy} (default: @code{'increment})
26119 A policy between @code{'increment} and @code{'unixtime}.
26124 @deftp {Data Type} knot-configuration
26125 Data type representing the Knot configuration.
26126 This type has the following parameters:
26129 @item @code{knot} (default: @code{knot})
26132 @item @code{run-directory} (default: @code{"/var/run/knot"})
26133 The run directory. This directory will be used for pid file and sockets.
26135 @item @code{includes} (default: @code{'()})
26136 A list of strings or file-like objects denoting other files that must be
26137 included at the top of the configuration file.
26139 @cindex secrets, Knot service
26140 This can be used to manage secrets out-of-band. For example, secret
26141 keys may be stored in an out-of-band file not managed by Guix, and
26142 thus not visible in @file{/gnu/store}---e.g., you could store secret
26143 key configuration in @file{/etc/knot/secrets.conf} and add this file
26144 to the @code{includes} list.
26146 One can generate a secret tsig key (for nsupdate and zone transfers with the
26147 keymgr command from the knot package. Note that the package is not automatically
26148 installed by the service. The following example shows how to generate a new
26152 keymgr -t mysecret > /etc/knot/secrets.conf
26153 chmod 600 /etc/knot/secrets.conf
26156 Also note that the generated key will be named @var{mysecret}, so it is the
26157 name that needs to be used in the @var{key} field of the
26158 @code{knot-acl-configuration} record and in other places that need to refer
26161 It can also be used to add configuration not supported by this interface.
26163 @item @code{listen-v4} (default: @code{"0.0.0.0"})
26164 An ip address on which to listen.
26166 @item @code{listen-v6} (default: @code{"::"})
26167 An ip address on which to listen.
26169 @item @code{listen-port} (default: @code{53})
26170 A port on which to listen.
26172 @item @code{keys} (default: @code{'()})
26173 The list of knot-key-configuration used by this configuration.
26175 @item @code{acls} (default: @code{'()})
26176 The list of knot-acl-configuration used by this configuration.
26178 @item @code{remotes} (default: @code{'()})
26179 The list of knot-remote-configuration used by this configuration.
26181 @item @code{zones} (default: @code{'()})
26182 The list of knot-zone-configuration used by this configuration.
26187 @subsubheading Knot Resolver Service
26189 @deffn {Scheme Variable} knot-resolver-service-type
26190 This is the type of the knot resolver service, whose value should be
26191 an @code{knot-resolver-configuration} object as in this example:
26194 (service knot-resolver-service-type
26195 (knot-resolver-configuration
26196 (kresd-config-file (plain-file "kresd.conf" "
26197 net.listen('192.168.0.1', 5353)
26198 user('knot-resolver', 'knot-resolver')
26199 modules = @{ 'hints > iterate', 'stats', 'predict' @}
26200 cache.size = 100 * MB
26204 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
26207 @deftp {Data Type} knot-resolver-configuration
26208 Data type representing the configuration of knot-resolver.
26211 @item @code{package} (default: @var{knot-resolver})
26212 Package object of the knot DNS resolver.
26214 @item @code{kresd-config-file} (default: %kresd.conf)
26215 File-like object of the kresd configuration file to use, by default it
26216 will listen on @code{127.0.0.1} and @code{::1}.
26218 @item @code{garbage-collection-interval} (default: 1000)
26219 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
26225 @subsubheading Dnsmasq Service
26227 @deffn {Scheme Variable} dnsmasq-service-type
26228 This is the type of the dnsmasq service, whose value should be an
26229 @code{dnsmasq-configuration} object as in this example:
26232 (service dnsmasq-service-type
26233 (dnsmasq-configuration
26235 (servers '("192.168.1.1"))))
26239 @deftp {Data Type} dnsmasq-configuration
26240 Data type representing the configuration of dnsmasq.
26243 @item @code{package} (default: @var{dnsmasq})
26244 Package object of the dnsmasq server.
26246 @item @code{no-hosts?} (default: @code{#f})
26247 When true, don't read the hostnames in /etc/hosts.
26249 @item @code{port} (default: @code{53})
26250 The port to listen on. Setting this to zero completely disables DNS
26251 responses, leaving only DHCP and/or TFTP functions.
26253 @item @code{local-service?} (default: @code{#t})
26254 Accept DNS queries only from hosts whose address is on a local subnet,
26255 ie a subnet for which an interface exists on the server.
26257 @item @code{listen-addresses} (default: @code{'()})
26258 Listen on the given IP addresses.
26260 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
26261 The file to read the IP address of the upstream nameservers from.
26263 @item @code{no-resolv?} (default: @code{#f})
26264 When true, don't read @var{resolv-file}.
26266 @item @code{servers} (default: @code{'()})
26267 Specify IP address of upstream servers directly.
26269 @item @code{addresses} (default: @code{'()})
26270 For each entry, specify an IP address to return for any host in the
26271 given domains. Queries in the domains are never forwarded and always
26272 replied to with the specified IP address.
26274 This is useful for redirecting hosts locally, for example:
26277 (service dnsmasq-service-type
26278 (dnsmasq-configuration
26280 '(; Redirect to a local web-server.
26281 "/example.org/127.0.0.1"
26282 ; Redirect subdomain to a specific IP.
26283 "/subdomain.example.org/192.168.1.42"))))
26286 Note that rules in @file{/etc/hosts} take precedence over this.
26288 @item @code{cache-size} (default: @code{150})
26289 Set the size of dnsmasq's cache. Setting the cache size to zero
26292 @item @code{negative-cache?} (default: @code{#t})
26293 When false, disable negative caching.
26295 @item @code{tftp-enable?} (default: @code{#f})
26296 Whether to enable the built-in TFTP server.
26298 @item @code{tftp-no-fail?} (default: @code{#f})
26299 If true, does not fail dnsmasq if the TFTP server could not start up.
26301 @item @code{tftp-single-port?} (default: @code{#f})
26302 Whether to use only one single port for TFTP.
26304 @item @code{tftp-secure?} (default: @code{#f})
26305 If true, only files owned by the user running the dnsmasq process are accessible.
26307 If dnsmasq is being run as root, different rules apply:
26308 @code{tftp-secure?} has no effect, but only files which have the
26309 world-readable bit set are accessible.
26311 @item @code{tftp-max} (default: @code{#f})
26312 If set, sets the maximal number of concurrent connections allowed.
26314 @item @code{tftp-mtu} (default: @code{#f})
26315 If set, sets the MTU for TFTP packets to that value.
26317 @item @code{tftp-no-blocksize?} (default: @code{#f})
26318 If true, stops the TFTP server from negotiating the blocksize with a client.
26320 @item @code{tftp-lowercase?} (default: @code{#f})
26321 Whether to convert all filenames in TFTP requests to lowercase.
26323 @item @code{tftp-port-range} (default: @code{#f})
26324 If set, fixes the dynamical ports (one per client) to the given range
26325 (@code{"<start>,<end>"}).
26327 @item @code{tftp-root} (default: @code{/var/empty,lo})
26328 Look for files to transfer using TFTP relative to the given directory.
26329 When this is set, TFTP paths which include @samp{..} are rejected, to stop clients
26330 getting outside the specified root. Absolute paths (starting with @samp{/}) are
26331 allowed, but they must be within the TFTP-root. If the optional interface
26332 argument is given, the directory is only used for TFTP requests via that
26335 @item @code{tftp-unique-root} (default: @code{#f})
26336 If set, add the IP or hardware address of the TFTP client as a path component
26337 on the end of the TFTP-root. Only valid if a TFTP root is set and the
26338 directory exists. Defaults to adding IP address (in standard dotted-quad
26341 For instance, if @option{--tftp-root} is @samp{/tftp} and client
26342 @samp{1.2.3.4} requests file @file{myfile} then the effective path will
26343 be @file{/tftp/1.2.3.4/myfile} if @file{/tftp/1.2.3.4} exists or
26344 @file{/tftp/myfile} otherwise. When @samp{=mac} is specified it will
26345 append the MAC address instead, using lowercase zero padded digits
26346 separated by dashes, e.g.: @samp{01-02-03-04-aa-bb}. Note that
26347 resolving MAC addresses is only possible if the client is in the local
26348 network or obtained a DHCP lease from dnsmasq.
26353 @subsubheading ddclient Service
26356 The ddclient service described below runs the ddclient daemon, which takes
26357 care of automatically updating DNS entries for service providers such as
26358 @uref{https://dyn.com/dns/, Dyn}.
26360 The following example show instantiates the service with its default
26364 (service ddclient-service-type)
26367 Note that ddclient needs to access credentials that are stored in a
26368 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
26369 @code{secret-file} below). You are expected to create this file manually, in
26370 an ``out-of-band'' fashion (you @emph{could} make this file part of the
26371 service configuration, for instance by using @code{plain-file}, but it will be
26372 world-readable @i{via} @file{/gnu/store}). See the examples in the
26373 @file{share/ddclient} directory of the @code{ddclient} package.
26375 @c %start of fragment
26377 Available @code{ddclient-configuration} fields are:
26379 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
26380 The ddclient package.
26384 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
26385 The period after which ddclient will retry to check IP and domain name.
26387 Defaults to @samp{300}.
26391 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
26392 Use syslog for the output.
26394 Defaults to @samp{#t}.
26398 @deftypevr {@code{ddclient-configuration} parameter} string mail
26401 Defaults to @samp{"root"}.
26405 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
26406 Mail failed update to user.
26408 Defaults to @samp{"root"}.
26412 @deftypevr {@code{ddclient-configuration} parameter} string pid
26413 The ddclient PID file.
26415 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
26419 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
26420 Enable SSL support.
26422 Defaults to @samp{#t}.
26426 @deftypevr {@code{ddclient-configuration} parameter} string user
26427 Specifies the user name or ID that is used when running ddclient
26430 Defaults to @samp{"ddclient"}.
26434 @deftypevr {@code{ddclient-configuration} parameter} string group
26435 Group of the user who will run the ddclient program.
26437 Defaults to @samp{"ddclient"}.
26441 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
26442 Secret file which will be appended to @file{ddclient.conf} file. This
26443 file contains credentials for use by ddclient. You are expected to
26444 create it manually.
26446 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
26450 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
26451 Extra options will be appended to @file{ddclient.conf} file.
26453 Defaults to @samp{()}.
26458 @c %end of fragment
26462 @subsection VPN Services
26463 @cindex VPN (virtual private network)
26464 @cindex virtual private network (VPN)
26466 The @code{(gnu services vpn)} module provides services related to
26467 @dfn{virtual private networks} (VPNs).
26469 @subsubheading OpenVPN
26471 It provides a @emph{client} service for your machine to connect to a
26472 VPN, and a @emph{server} service for your machine to host a VPN@.
26474 @deffn {Scheme Procedure} openvpn-client-service @
26475 [#:config (openvpn-client-configuration)]
26477 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
26480 @deffn {Scheme Procedure} openvpn-server-service @
26481 [#:config (openvpn-server-configuration)]
26483 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
26485 Both can be run simultaneously.
26488 @c %automatically generated documentation
26490 Available @code{openvpn-client-configuration} fields are:
26492 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
26493 The OpenVPN package.
26497 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
26498 The OpenVPN pid file.
26500 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
26504 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
26505 The protocol (UDP or TCP) used to open a channel between clients and
26508 Defaults to @samp{udp}.
26512 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
26513 The device type used to represent the VPN connection.
26515 Defaults to @samp{tun}.
26519 If you do not have some of these files (eg.@: you use a username and
26520 password), you can disable any of the following three fields by setting
26521 it to @code{'disabled}.
26523 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
26524 The certificate authority to check connections against.
26526 Defaults to @samp{"/etc/openvpn/ca.crt"}.
26530 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
26531 The certificate of the machine the daemon is running on. It should be
26532 signed by the authority given in @code{ca}.
26534 Defaults to @samp{"/etc/openvpn/client.crt"}.
26538 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
26539 The key of the machine the daemon is running on. It must be the key whose
26540 certificate is @code{cert}.
26542 Defaults to @samp{"/etc/openvpn/client.key"}.
26546 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
26547 Whether to use the lzo compression algorithm.
26549 Defaults to @samp{#t}.
26553 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
26554 Don't re-read key files across SIGUSR1 or --ping-restart.
26556 Defaults to @samp{#t}.
26560 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
26561 Don't close and reopen TUN/TAP device or run up/down scripts across
26562 SIGUSR1 or --ping-restart restarts.
26564 Defaults to @samp{#t}.
26568 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
26569 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
26570 poll/epoll/select prior to the write operation.
26572 Defaults to @samp{#f}.
26575 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
26578 Defaults to @samp{3}.
26582 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
26583 Add an additional layer of HMAC authentication on top of the TLS control
26584 channel to protect against DoS attacks.
26586 Defaults to @samp{#f}.
26590 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
26591 Authenticate with server using username/password. The option is a file
26592 containing username/password on 2 lines. Do not use a file-like object as it
26593 would be added to the store and readable by any user.
26595 Defaults to @samp{'disabled}.
26598 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
26599 Whether to check the server certificate has server usage extension.
26601 Defaults to @samp{#t}.
26605 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
26606 Bind to a specific local port number.
26608 Defaults to @samp{#f}.
26612 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
26613 Retry resolving server address.
26615 Defaults to @samp{#t}.
26619 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
26620 A list of remote servers to connect to.
26622 Defaults to @samp{()}.
26624 Available @code{openvpn-remote-configuration} fields are:
26626 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
26629 Defaults to @samp{"my-server"}.
26633 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
26634 Port number the server listens to.
26636 Defaults to @samp{1194}.
26641 @c %end of automatic openvpn-client documentation
26643 @c %automatically generated documentation
26645 Available @code{openvpn-server-configuration} fields are:
26647 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
26648 The OpenVPN package.
26652 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
26653 The OpenVPN pid file.
26655 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
26659 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
26660 The protocol (UDP or TCP) used to open a channel between clients and
26663 Defaults to @samp{udp}.
26667 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
26668 The device type used to represent the VPN connection.
26670 Defaults to @samp{tun}.
26674 If you do not have some of these files (eg.@: you use a username and
26675 password), you can disable any of the following three fields by setting
26676 it to @code{'disabled}.
26678 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
26679 The certificate authority to check connections against.
26681 Defaults to @samp{"/etc/openvpn/ca.crt"}.
26685 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
26686 The certificate of the machine the daemon is running on. It should be
26687 signed by the authority given in @code{ca}.
26689 Defaults to @samp{"/etc/openvpn/client.crt"}.
26693 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
26694 The key of the machine the daemon is running on. It must be the key whose
26695 certificate is @code{cert}.
26697 Defaults to @samp{"/etc/openvpn/client.key"}.
26701 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
26702 Whether to use the lzo compression algorithm.
26704 Defaults to @samp{#t}.
26708 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
26709 Don't re-read key files across SIGUSR1 or --ping-restart.
26711 Defaults to @samp{#t}.
26715 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
26716 Don't close and reopen TUN/TAP device or run up/down scripts across
26717 SIGUSR1 or --ping-restart restarts.
26719 Defaults to @samp{#t}.
26723 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
26724 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
26725 poll/epoll/select prior to the write operation.
26727 Defaults to @samp{#f}.
26730 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
26733 Defaults to @samp{3}.
26737 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
26738 Add an additional layer of HMAC authentication on top of the TLS control
26739 channel to protect against DoS attacks.
26741 Defaults to @samp{#f}.
26745 @deftypevr {@code{openvpn-server-configuration} parameter} number port
26746 Specifies the port number on which the server listens.
26748 Defaults to @samp{1194}.
26752 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
26753 An ip and mask specifying the subnet inside the virtual network.
26755 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
26759 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
26760 A CIDR notation specifying the IPv6 subnet inside the virtual network.
26762 Defaults to @samp{#f}.
26766 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
26767 The Diffie-Hellman parameters file.
26769 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
26773 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
26774 The file that records client IPs.
26776 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
26780 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
26781 When true, the server will act as a gateway for its clients.
26783 Defaults to @samp{#f}.
26787 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
26788 When true, clients are allowed to talk to each other inside the VPN.
26790 Defaults to @samp{#f}.
26794 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
26795 Causes ping-like messages to be sent back and forth over the link so
26796 that each side knows when the other side has gone down. @code{keepalive}
26797 requires a pair. The first element is the period of the ping sending,
26798 and the second element is the timeout before considering the other side
26803 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
26804 The maximum number of clients.
26806 Defaults to @samp{100}.
26810 @deftypevr {@code{openvpn-server-configuration} parameter} string status
26811 The status file. This file shows a small report on current connection.
26812 It is truncated and rewritten every minute.
26814 Defaults to @samp{"/var/run/openvpn/status"}.
26818 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
26819 The list of configuration for some clients.
26821 Defaults to @samp{()}.
26823 Available @code{openvpn-ccd-configuration} fields are:
26825 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
26828 Defaults to @samp{"client"}.
26832 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
26835 Defaults to @samp{#f}.
26839 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
26842 Defaults to @samp{#f}.
26849 @c %end of automatic openvpn-server documentation
26851 @subsubheading Wireguard
26853 @defvr {Scheme Variable} wireguard-service-type
26854 A service type for a Wireguard tunnel interface. Its value must be a
26855 @code{wireguard-configuration} record as in this example:
26858 (service wireguard-service-type
26859 (wireguard-configuration
26864 (endpoint "my.wireguard.com:51820")
26865 (public-key "hzpKg9X1yqu1axN6iJp0mWf6BZGo8m1wteKwtTmDGF4=")
26866 (allowed-ips '("10.0.0.2/32")))))))
26871 @deftp {Data Type} wireguard-configuration
26872 Data type representing the configuration of the Wireguard service.
26875 @item @code{wireguard}
26876 The wireguard package to use for this service.
26878 @item @code{interface} (default: @code{"wg0"})
26879 The interface name for the VPN.
26881 @item @code{addresses} (default: @code{'("10.0.0.1/32")})
26882 The IP addresses to be assigned to the above interface.
26884 @item @code{private-key} (default: @code{"/etc/wireguard/private.key"})
26885 The private key file for the interface. It is automatically generated if
26886 the file does not exist.
26888 @item @code{peers} (default: @code{'()})
26889 The authorized peers on this interface. This is a list of
26890 @var{wireguard-peer} records.
26895 @deftp {Data Type} wireguard-peer
26896 Data type representing a Wireguard peer attached to a given interface.
26902 @item @code{endpoint} (default: @code{#f})
26903 The optional endpoint for the peer, such as
26904 @code{"demo.wireguard.com:51820"}.
26906 @item @code{public-key}
26907 The peer public-key represented as a base64 string.
26909 @item @code{allowed-ips}
26910 A list of IP addresses from which incoming traffic for this peer is
26911 allowed and to which incoming traffic for this peer is directed.
26916 @node Network File System
26917 @subsection Network File System
26920 The @code{(gnu services nfs)} module provides the following services,
26921 which are most commonly used in relation to mounting or exporting
26922 directory trees as @dfn{network file systems} (NFS).
26924 While it is possible to use the individual components that together make
26925 up a Network File System service, we recommended to configure an NFS
26926 server with the @code{nfs-service-type}.
26928 @subsubheading NFS Service
26929 @cindex NFS, server
26931 The NFS service takes care of setting up all NFS component services,
26932 kernel configuration file systems, and installs configuration files in
26933 the locations that NFS expects.
26935 @defvr {Scheme Variable} nfs-service-type
26936 A service type for a complete NFS server.
26939 @deftp {Data Type} nfs-configuration
26940 This data type represents the configuration of the NFS service and all
26943 It has the following parameters:
26945 @item @code{nfs-utils} (default: @code{nfs-utils})
26946 The nfs-utils package to use.
26948 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
26949 If a list of string values is provided, the @command{rpc.nfsd} daemon
26950 will be limited to supporting the given versions of the NFS protocol.
26952 @item @code{exports} (default: @code{'()})
26953 This is a list of directories the NFS server should export. Each entry
26954 is a list consisting of two elements: a directory name and a string
26955 containing all options. This is an example in which the directory
26956 @file{/export} is served to all NFS clients as a read-only share:
26962 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
26965 @item @code{rpcmountd-port} (default: @code{#f})
26966 The network port that the @command{rpc.mountd} daemon should use.
26968 @item @code{rpcstatd-port} (default: @code{#f})
26969 The network port that the @command{rpc.statd} daemon should use.
26971 @item @code{rpcbind} (default: @code{rpcbind})
26972 The rpcbind package to use.
26974 @item @code{idmap-domain} (default: @code{"localdomain"})
26975 The local NFSv4 domain name.
26977 @item @code{nfsd-port} (default: @code{2049})
26978 The network port that the @command{nfsd} daemon should use.
26980 @item @code{nfsd-threads} (default: @code{8})
26981 The number of threads used by the @command{nfsd} daemon.
26983 @item @code{nfsd-tcp?} (default: @code{#t})
26984 Whether the @command{nfsd} daemon should listen on a TCP socket.
26986 @item @code{nfsd-udp?} (default: @code{#f})
26987 Whether the @command{nfsd} daemon should listen on a UDP socket.
26989 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
26990 The directory where the pipefs file system is mounted.
26992 @item @code{debug} (default: @code{'()"})
26993 A list of subsystems for which debugging output should be enabled. This
26994 is a list of symbols. Any of these symbols are valid: @code{nfsd},
26995 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
26999 If you don't need a complete NFS service or prefer to build it yourself
27000 you can use the individual component services that are documented below.
27002 @subsubheading RPC Bind Service
27005 The RPC Bind service provides a facility to map program numbers into
27006 universal addresses.
27007 Many NFS related services use this facility. Hence it is automatically
27008 started when a dependent service starts.
27010 @defvr {Scheme Variable} rpcbind-service-type
27011 A service type for the RPC portmapper daemon.
27015 @deftp {Data Type} rpcbind-configuration
27016 Data type representing the configuration of the RPC Bind Service.
27017 This type has the following parameters:
27019 @item @code{rpcbind} (default: @code{rpcbind})
27020 The rpcbind package to use.
27022 @item @code{warm-start?} (default: @code{#t})
27023 If this parameter is @code{#t}, then the daemon will read a
27024 state file on startup thus reloading state information saved by a previous
27030 @subsubheading Pipefs Pseudo File System
27034 The pipefs file system is used to transfer NFS related data
27035 between the kernel and user space programs.
27037 @defvr {Scheme Variable} pipefs-service-type
27038 A service type for the pipefs pseudo file system.
27041 @deftp {Data Type} pipefs-configuration
27042 Data type representing the configuration of the pipefs pseudo file system service.
27043 This type has the following parameters:
27045 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27046 The directory to which the file system is to be attached.
27051 @subsubheading GSS Daemon Service
27054 @cindex global security system
27056 The @dfn{global security system} (GSS) daemon provides strong security for RPC
27058 Before exchanging RPC requests an RPC client must establish a security
27059 context. Typically this is done using the Kerberos command @command{kinit}
27060 or automatically at login time using PAM services (@pxref{Kerberos Services}).
27062 @defvr {Scheme Variable} gss-service-type
27063 A service type for the Global Security System (GSS) daemon.
27066 @deftp {Data Type} gss-configuration
27067 Data type representing the configuration of the GSS daemon service.
27068 This type has the following parameters:
27070 @item @code{nfs-utils} (default: @code{nfs-utils})
27071 The package in which the @command{rpc.gssd} command is to be found.
27073 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27074 The directory where the pipefs file system is mounted.
27080 @subsubheading IDMAP Daemon Service
27082 @cindex name mapper
27084 The idmap daemon service provides mapping between user IDs and user names.
27085 Typically it is required in order to access file systems mounted via NFSv4.
27087 @defvr {Scheme Variable} idmap-service-type
27088 A service type for the Identity Mapper (IDMAP) daemon.
27091 @deftp {Data Type} idmap-configuration
27092 Data type representing the configuration of the IDMAP daemon service.
27093 This type has the following parameters:
27095 @item @code{nfs-utils} (default: @code{nfs-utils})
27096 The package in which the @command{rpc.idmapd} command is to be found.
27098 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27099 The directory where the pipefs file system is mounted.
27101 @item @code{domain} (default: @code{#f})
27102 The local NFSv4 domain name.
27103 This must be a string or @code{#f}.
27104 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
27106 @item @code{verbosity} (default: @code{0})
27107 The verbosity level of the daemon.
27112 @node Continuous Integration
27113 @subsection Continuous Integration
27115 @cindex continuous integration
27116 @uref{https://guix.gnu.org/cuirass/, Cuirass} is a continuous
27117 integration tool for Guix. It can be used both for development and for
27118 providing substitutes to others (@pxref{Substitutes}).
27120 The @code{(gnu services cuirass)} module provides the following service.
27122 @defvr {Scheme Procedure} cuirass-service-type
27123 The type of the Cuirass service. Its value must be a
27124 @code{cuirass-configuration} object, as described below.
27127 To add build jobs, you have to set the @code{specifications} field of
27128 the configuration. For instance, the following example will build all
27129 the packages provided by the @code{my-channel} channel.
27132 (define %cuirass-specs
27133 #~(list (specification
27134 (name "my-channel")
27135 (build '(channels my-channel))
27139 (url "https://my-channel.git"))
27140 %default-channels)))))
27142 (service cuirass-service-type
27143 (cuirass-configuration
27144 (specifications %cuirass-specs)))
27147 To build the @code{linux-libre} package defined by the default Guix
27148 channel, one can use the following configuration.
27151 (define %cuirass-specs
27152 #~(list (specification
27154 (build '(packages "linux-libre")))))
27156 (service cuirass-service-type
27157 (cuirass-configuration
27158 (specifications %cuirass-specs)))
27161 The other configuration possibilities, as well as the specification
27162 record itself are described in the Cuirass manual
27163 (@pxref{Specifications,,, cuirass, Cuirass}).
27165 While information related to build jobs is located directly in the
27166 specifications, global settings for the @command{cuirass} process are
27167 accessible in other @code{cuirass-configuration} fields.
27169 @deftp {Data Type} cuirass-configuration
27170 Data type representing the configuration of Cuirass.
27173 @item @code{cuirass} (default: @code{cuirass})
27174 The Cuirass package to use.
27176 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
27177 Location of the log file.
27179 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
27180 Location of the log file used by the web interface.
27182 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
27183 Location of the repository cache.
27185 @item @code{user} (default: @code{"cuirass"})
27186 Owner of the @code{cuirass} process.
27188 @item @code{group} (default: @code{"cuirass"})
27189 Owner's group of the @code{cuirass} process.
27191 @item @code{interval} (default: @code{60})
27192 Number of seconds between the poll of the repositories followed by the
27195 @item @code{parameters} (default: @code{#f})
27196 Read parameters from the given @var{parameters} file. The supported
27197 parameters are described here (@pxref{Parameters,,, cuirass, Cuirass}).
27199 @item @code{remote-server} (default: @code{#f})
27200 A @code{cuirass-remote-server-configuration} record to use the build
27201 remote mechanism or @code{#f} to use the default build mechanism.
27203 @item @code{database} (default: @code{"dbname=cuirass host=/var/run/postgresql"})
27204 Use @var{database} as the database containing the jobs and the past
27205 build results. Since Cuirass uses PostgreSQL as a database engine,
27206 @var{database} must be a string such as @code{"dbname=cuirass
27209 @item @code{port} (default: @code{8081})
27210 Port number used by the HTTP server.
27212 @item @code{host} (default: @code{"localhost"})
27213 Listen on the network interface for @var{host}. The default is to
27214 accept connections from localhost.
27216 @item @code{specifications} (default: @code{#~'()})
27217 A gexp (@pxref{G-Expressions}) that evaluates to a list of
27218 specifications records. The specification record is described in the
27219 Cuirass manual (@pxref{Specifications,,, cuirass, Cuirass}).
27221 @item @code{use-substitutes?} (default: @code{#f})
27222 This allows using substitutes to avoid building every dependencies of a job
27225 @item @code{one-shot?} (default: @code{#f})
27226 Only evaluate specifications and build derivations once.
27228 @item @code{fallback?} (default: @code{#f})
27229 When substituting a pre-built binary fails, fall back to building
27232 @item @code{extra-options} (default: @code{'()})
27233 Extra options to pass when running the Cuirass processes.
27238 @cindex remote build
27239 @subsubheading Cuirass remote building
27241 Cuirass supports two mechanisms to build derivations.
27244 @item Using the local Guix daemon.
27245 This is the default build mechanism. Once the build jobs are
27246 evaluated, they are sent to the local Guix daemon. Cuirass then
27247 listens to the Guix daemon output to detect the various build events.
27249 @item Using the remote build mechanism.
27250 The build jobs are not submitted to the local Guix daemon. Instead, a
27251 remote server dispatches build requests to the connect remote workers,
27252 according to the build priorities.
27256 To enable this build mode a @code{cuirass-remote-server-configuration}
27257 record must be passed as @code{remote-server} argument of the
27258 @code{cuirass-configuration} record. The
27259 @code{cuirass-remote-server-configuration} record is described below.
27261 This build mode scales way better than the default build mode. This is
27262 the build mode that is used on the GNU Guix build farm at
27263 @url{https://ci.guix.gnu.org}. It should be preferred when using
27264 Cuirass to build large amount of packages.
27266 @deftp {Data Type} cuirass-remote-server-configuration
27267 Data type representing the configuration of the Cuirass remote-server.
27270 @item @code{backend-port} (default: @code{5555})
27271 The TCP port for communicating with @code{remote-worker} processes
27272 using ZMQ. It defaults to @code{5555}.
27274 @item @code{log-port} (default: @code{5556})
27275 The TCP port of the log server. It defaults to @code{5556}.
27277 @item @code{publish-port} (default: @code{5557})
27278 The TCP port of the publish server. It defaults to @code{5557}.
27280 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-server.log"})
27281 Location of the log file.
27283 @item @code{cache} (default: @code{"/var/cache/cuirass/remote"})
27284 Use @var{cache} directory to cache build log files.
27286 @item @code{trigger-url} (default: @code{#f})
27287 Once a substitute is successfully fetched, trigger substitute baking at
27290 @item @code{public-key}
27291 @item @code{private-key}
27292 Use the specific @var{file}s as the public/private key pair used to sign
27293 the store items being published.
27298 At least one remote worker must also be started on any machine of the
27299 local network to actually perform the builds and report their status.
27301 @deftp {Data Type} cuirass-remote-worker-configuration
27302 Data type representing the configuration of the Cuirass remote-worker.
27305 @item @code{cuirass} (default: @code{cuirass})
27306 The Cuirass package to use.
27308 @item @code{workers} (default: @code{1})
27309 Start @var{workers} parallel workers.
27311 @item @code{server} (default: @code{#f})
27312 Do not use Avahi discovery and connect to the given @code{server} IP
27315 @item @code{systems} (default: @code{(list (%current-system))})
27316 Only request builds for the given @var{systems}.
27318 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-worker.log"})
27319 Location of the log file.
27321 @item @code{publish-port} (default: @code{5558})
27322 The TCP port of the publish server. It defaults to @code{5558}.
27324 @item @code{public-key}
27325 @item @code{private-key}
27326 Use the specific @var{file}s as the public/private key pair used to sign
27327 the store items being published.
27332 @node Power Management Services
27333 @subsection Power Management Services
27336 @cindex power management with TLP
27337 @subsubheading TLP daemon
27339 The @code{(gnu services pm)} module provides a Guix service definition
27340 for the Linux power management tool TLP.
27342 TLP enables various powersaving modes in userspace and kernel.
27343 Contrary to @code{upower-service}, it is not a passive,
27344 monitoring tool, as it will apply custom settings each time a new power
27345 source is detected. More information can be found at
27346 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
27348 @deffn {Scheme Variable} tlp-service-type
27349 The service type for the TLP tool. The default settings are optimised
27350 for battery life on most systems, but you can tweak them to your heart's
27351 content by adding a valid @code{tlp-configuration}:
27353 (service tlp-service-type
27355 (cpu-scaling-governor-on-ac (list "performance"))
27356 (sched-powersave-on-bat? #t)))
27360 Each parameter definition is preceded by its type; for example,
27361 @samp{boolean foo} indicates that the @code{foo} parameter
27362 should be specified as a boolean. Types starting with
27363 @code{maybe-} denote parameters that won't show up in TLP config file
27364 when their value is @code{'disabled}.
27366 @c The following documentation was initially generated by
27367 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
27368 @c documentation is better, so we shouldn't hesitate to edit below as
27369 @c needed. However if the change you want to make to this documentation
27370 @c can be done in an automated way, it's probably easier to change
27371 @c (generate-documentation) than to make it below and have to deal with
27372 @c the churn as TLP updates.
27374 Available @code{tlp-configuration} fields are:
27376 @deftypevr {@code{tlp-configuration} parameter} package tlp
27381 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
27382 Set to true if you wish to enable TLP.
27384 Defaults to @samp{#t}.
27388 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
27389 Default mode when no power supply can be detected. Alternatives are AC
27392 Defaults to @samp{"AC"}.
27396 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
27397 Number of seconds Linux kernel has to wait after the disk goes idle,
27398 before syncing on AC.
27400 Defaults to @samp{0}.
27404 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
27405 Same as @code{disk-idle-ac} but on BAT mode.
27407 Defaults to @samp{2}.
27411 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
27412 Dirty pages flushing periodicity, expressed in seconds.
27414 Defaults to @samp{15}.
27418 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
27419 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
27421 Defaults to @samp{60}.
27425 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
27426 CPU frequency scaling governor on AC mode. With intel_pstate driver,
27427 alternatives are powersave and performance. With acpi-cpufreq driver,
27428 alternatives are ondemand, powersave, performance and conservative.
27430 Defaults to @samp{disabled}.
27434 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
27435 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
27437 Defaults to @samp{disabled}.
27441 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
27442 Set the min available frequency for the scaling governor on AC.
27444 Defaults to @samp{disabled}.
27448 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
27449 Set the max available frequency for the scaling governor on AC.
27451 Defaults to @samp{disabled}.
27455 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
27456 Set the min available frequency for the scaling governor on BAT.
27458 Defaults to @samp{disabled}.
27462 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
27463 Set the max available frequency for the scaling governor on BAT.
27465 Defaults to @samp{disabled}.
27469 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
27470 Limit the min P-state to control the power dissipation of the CPU, in AC
27471 mode. Values are stated as a percentage of the available performance.
27473 Defaults to @samp{disabled}.
27477 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
27478 Limit the max P-state to control the power dissipation of the CPU, in AC
27479 mode. Values are stated as a percentage of the available performance.
27481 Defaults to @samp{disabled}.
27485 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
27486 Same as @code{cpu-min-perf-on-ac} on BAT mode.
27488 Defaults to @samp{disabled}.
27492 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
27493 Same as @code{cpu-max-perf-on-ac} on BAT mode.
27495 Defaults to @samp{disabled}.
27499 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
27500 Enable CPU turbo boost feature on AC mode.
27502 Defaults to @samp{disabled}.
27506 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
27507 Same as @code{cpu-boost-on-ac?} on BAT mode.
27509 Defaults to @samp{disabled}.
27513 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
27514 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
27515 used under light load conditions.
27517 Defaults to @samp{#f}.
27521 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
27522 Same as @code{sched-powersave-on-ac?} but on BAT mode.
27524 Defaults to @samp{#t}.
27528 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
27529 Enable Linux kernel NMI watchdog.
27531 Defaults to @samp{#f}.
27535 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
27536 For Linux kernels with PHC patch applied, change CPU voltages. An
27537 example value would be @samp{"F:V F:V F:V F:V"}.
27539 Defaults to @samp{disabled}.
27543 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
27544 Set CPU performance versus energy saving policy on AC@. Alternatives are
27545 performance, normal, powersave.
27547 Defaults to @samp{"performance"}.
27551 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
27552 Same as @code{energy-perf-policy-ac} but on BAT mode.
27554 Defaults to @samp{"powersave"}.
27558 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
27563 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
27564 Hard disk advanced power management level.
27568 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
27569 Same as @code{disk-apm-bat} but on BAT mode.
27573 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
27574 Hard disk spin down timeout. One value has to be specified for each
27575 declared hard disk.
27577 Defaults to @samp{disabled}.
27581 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
27582 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
27584 Defaults to @samp{disabled}.
27588 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
27589 Select IO scheduler for disk devices. One value has to be specified for
27590 each declared hard disk. Example alternatives are cfq, deadline and
27593 Defaults to @samp{disabled}.
27597 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
27598 SATA aggressive link power management (ALPM) level. Alternatives are
27599 min_power, medium_power, max_performance.
27601 Defaults to @samp{"max_performance"}.
27605 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
27606 Same as @code{sata-linkpwr-ac} but on BAT mode.
27608 Defaults to @samp{"min_power"}.
27612 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
27613 Exclude specified SATA host devices for link power management.
27615 Defaults to @samp{disabled}.
27619 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
27620 Enable Runtime Power Management for AHCI controller and disks on AC
27623 Defaults to @samp{disabled}.
27627 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
27628 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
27630 Defaults to @samp{disabled}.
27634 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
27635 Seconds of inactivity before disk is suspended.
27637 Defaults to @samp{15}.
27641 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
27642 PCI Express Active State Power Management level. Alternatives are
27643 default, performance, powersave.
27645 Defaults to @samp{"performance"}.
27649 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
27650 Same as @code{pcie-aspm-ac} but on BAT mode.
27652 Defaults to @samp{"powersave"}.
27656 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
27657 Radeon graphics clock speed level. Alternatives are low, mid, high,
27660 Defaults to @samp{"high"}.
27664 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
27665 Same as @code{radeon-power-ac} but on BAT mode.
27667 Defaults to @samp{"low"}.
27671 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
27672 Radeon dynamic power management method (DPM). Alternatives are battery,
27675 Defaults to @samp{"performance"}.
27679 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
27680 Same as @code{radeon-dpm-state-ac} but on BAT mode.
27682 Defaults to @samp{"battery"}.
27686 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
27687 Radeon DPM performance level. Alternatives are auto, low, high.
27689 Defaults to @samp{"auto"}.
27693 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
27694 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
27696 Defaults to @samp{"auto"}.
27700 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
27701 Wifi power saving mode.
27703 Defaults to @samp{#f}.
27707 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
27708 Same as @code{wifi-power-ac?} but on BAT mode.
27710 Defaults to @samp{#t}.
27714 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
27715 Disable wake on LAN.
27717 Defaults to @samp{#t}.
27721 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
27722 Timeout duration in seconds before activating audio power saving on
27723 Intel HDA and AC97 devices. A value of 0 disables power saving.
27725 Defaults to @samp{0}.
27729 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
27730 Same as @code{sound-powersave-ac} but on BAT mode.
27732 Defaults to @samp{1}.
27736 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
27737 Disable controller in powersaving mode on Intel HDA devices.
27739 Defaults to @samp{#t}.
27743 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
27744 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
27745 powered on again by releasing (and reinserting) the eject lever or by
27746 pressing the disc eject button on newer models.
27748 Defaults to @samp{#f}.
27752 @deftypevr {@code{tlp-configuration} parameter} string bay-device
27753 Name of the optical drive device to power off.
27755 Defaults to @samp{"sr0"}.
27759 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
27760 Runtime Power Management for PCI(e) bus devices. Alternatives are on
27763 Defaults to @samp{"on"}.
27767 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
27768 Same as @code{runtime-pm-ac} but on BAT mode.
27770 Defaults to @samp{"auto"}.
27774 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
27775 Runtime Power Management for all PCI(e) bus devices, except blacklisted
27778 Defaults to @samp{#t}.
27782 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
27783 Exclude specified PCI(e) device addresses from Runtime Power Management.
27785 Defaults to @samp{disabled}.
27789 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
27790 Exclude PCI(e) devices assigned to the specified drivers from Runtime
27795 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
27796 Enable USB autosuspend feature.
27798 Defaults to @samp{#t}.
27802 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
27803 Exclude specified devices from USB autosuspend.
27805 Defaults to @samp{disabled}.
27809 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
27810 Exclude WWAN devices from USB autosuspend.
27812 Defaults to @samp{#t}.
27816 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
27817 Include specified devices into USB autosuspend, even if they are already
27818 excluded by the driver or via @code{usb-blacklist-wwan?}.
27820 Defaults to @samp{disabled}.
27824 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
27825 Enable USB autosuspend before shutdown.
27827 Defaults to @samp{disabled}.
27831 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
27832 Restore radio device state (bluetooth, wifi, wwan) from previous
27833 shutdown on system startup.
27835 Defaults to @samp{#f}.
27840 @cindex CPU frequency scaling with thermald
27841 @subsubheading Thermald daemon
27843 The @code{(gnu services pm)} module provides an interface to
27844 thermald, a CPU frequency scaling service which helps prevent overheating.
27846 @defvr {Scheme Variable} thermald-service-type
27847 This is the service type for
27848 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
27849 Thermal Daemon, which is responsible for controlling the thermal state
27850 of processors and preventing overheating.
27853 @deftp {Data Type} thermald-configuration
27854 Data type representing the configuration of @code{thermald-service-type}.
27857 @item @code{ignore-cpuid-check?} (default: @code{#f})
27858 Ignore cpuid check for supported CPU models.
27860 @item @code{thermald} (default: @var{thermald})
27861 Package object of thermald.
27866 @node Audio Services
27867 @subsection Audio Services
27869 The @code{(gnu services audio)} module provides a service to start MPD
27870 (the Music Player Daemon).
27873 @subsubheading Music Player Daemon
27875 The Music Player Daemon (MPD) is a service that can play music while
27876 being controlled from the local machine or over the network by a variety
27879 The following example shows how one might run @code{mpd} as user
27880 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
27883 (service mpd-service-type
27889 @defvr {Scheme Variable} mpd-service-type
27890 The service type for @command{mpd}
27893 @deftp {Data Type} mpd-configuration
27894 Data type representing the configuration of @command{mpd}.
27897 @item @code{user} (default: @code{"mpd"})
27898 The user to run mpd as.
27900 @item @code{music-dir} (default: @code{"~/Music"})
27901 The directory to scan for music files.
27903 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
27904 The directory to store playlists.
27906 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
27907 The location of the music database.
27909 @item @code{state-file} (default: @code{"~/.mpd/state"})
27910 The location of the file that stores current MPD's state.
27912 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
27913 The location of the sticker database.
27915 @item @code{port} (default: @code{"6600"})
27916 The port to run mpd on.
27918 @item @code{address} (default: @code{"any"})
27919 The address that mpd will bind to. To use a Unix domain socket,
27920 an absolute path can be specified here.
27922 @item @code{outputs} (default: @code{"(list (mpd-output))"})
27923 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
27928 @deftp {Data Type} mpd-output
27929 Data type representing an @command{mpd} audio output.
27932 @item @code{name} (default: @code{"MPD"})
27933 The name of the audio output.
27935 @item @code{type} (default: @code{"pulse"})
27936 The type of audio output.
27938 @item @code{enabled?} (default: @code{#t})
27939 Specifies whether this audio output is enabled when MPD is started. By
27940 default, all audio outputs are enabled. This is just the default
27941 setting when there is no state file; with a state file, the previous
27944 @item @code{tags?} (default: @code{#t})
27945 If set to @code{#f}, then MPD will not send tags to this output. This
27946 is only useful for output plugins that can receive tags, for example the
27947 @code{httpd} output plugin.
27949 @item @code{always-on?} (default: @code{#f})
27950 If set to @code{#t}, then MPD attempts to keep this audio output always
27951 open. This may be useful for streaming servers, when you don’t want to
27952 disconnect all listeners even when playback is accidentally stopped.
27954 @item @code{mixer-type}
27955 This field accepts a symbol that specifies which mixer should be used
27956 for this audio output: the @code{hardware} mixer, the @code{software}
27957 mixer, the @code{null} mixer (allows setting the volume, but with no
27958 effect; this can be used as a trick to implement an external mixer
27959 External Mixer) or no mixer (@code{none}).
27961 @item @code{extra-options} (default: @code{'()})
27962 An association list of option symbols to string values to be appended to
27963 the audio output configuration.
27968 The following example shows a configuration of @code{mpd} that provides
27969 an HTTP audio streaming output.
27972 (service mpd-service-type
27980 `((encoder . "vorbis")
27981 (port . "8080"))))))))
27985 @node Virtualization Services
27986 @subsection Virtualization Services
27988 The @code{(gnu services virtualization)} module provides services for
27989 the libvirt and virtlog daemons, as well as other virtualization-related
27992 @subsubheading Libvirt daemon
27994 @code{libvirtd} is the server side daemon component of the libvirt
27995 virtualization management system. This daemon runs on host servers
27996 and performs required management tasks for virtualized guests.
27998 @deffn {Scheme Variable} libvirt-service-type
27999 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
28000 Its value must be a @code{libvirt-configuration}.
28003 (service libvirt-service-type
28004 (libvirt-configuration
28005 (unix-sock-group "libvirt")
28006 (tls-port "16555")))
28010 @c Auto-generated with (generate-libvirt-documentation)
28011 Available @code{libvirt-configuration} fields are:
28013 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
28018 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
28019 Flag listening for secure TLS connections on the public TCP/IP port.
28020 You must set @code{listen} for this to have any effect.
28022 It is necessary to setup a CA and issue server certificates before using
28025 Defaults to @samp{#t}.
28029 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
28030 Listen for unencrypted TCP connections on the public TCP/IP port. You must
28031 set @code{listen} for this to have any effect.
28033 Using the TCP socket requires SASL authentication by default. Only SASL
28034 mechanisms which support data encryption are allowed. This is
28035 DIGEST_MD5 and GSSAPI (Kerberos5).
28037 Defaults to @samp{#f}.
28041 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
28042 Port for accepting secure TLS connections. This can be a port number,
28045 Defaults to @samp{"16514"}.
28049 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
28050 Port for accepting insecure TCP connections. This can be a port number,
28053 Defaults to @samp{"16509"}.
28057 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
28058 IP address or hostname used for client connections.
28060 Defaults to @samp{"0.0.0.0"}.
28064 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
28065 Flag toggling mDNS advertisement of the libvirt service.
28067 Alternatively can disable for all services on a host by stopping the
28070 Defaults to @samp{#f}.
28074 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
28075 Default mDNS advertisement name. This must be unique on the immediate
28078 Defaults to @samp{"Virtualization Host <hostname>"}.
28082 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
28083 UNIX domain socket group ownership. This can be used to allow a
28084 'trusted' set of users access to management capabilities without
28087 Defaults to @samp{"root"}.
28091 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
28092 UNIX socket permissions for the R/O socket. This is used for monitoring
28095 Defaults to @samp{"0777"}.
28099 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
28100 UNIX socket permissions for the R/W socket. Default allows only root.
28101 If PolicyKit is enabled on the socket, the default will change to allow
28102 everyone (eg, 0777)
28104 Defaults to @samp{"0770"}.
28108 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
28109 UNIX socket permissions for the admin socket. Default allows only owner
28110 (root), do not change it unless you are sure to whom you are exposing
28113 Defaults to @samp{"0777"}.
28117 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
28118 The directory in which sockets will be found/created.
28120 Defaults to @samp{"/var/run/libvirt"}.
28124 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
28125 Authentication scheme for UNIX read-only sockets. By default socket
28126 permissions allow anyone to connect
28128 Defaults to @samp{"polkit"}.
28132 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
28133 Authentication scheme for UNIX read-write sockets. By default socket
28134 permissions only allow root. If PolicyKit support was compiled into
28135 libvirt, the default will be to use 'polkit' auth.
28137 Defaults to @samp{"polkit"}.
28141 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
28142 Authentication scheme for TCP sockets. If you don't enable SASL, then
28143 all TCP traffic is cleartext. Don't do this outside of a dev/test
28146 Defaults to @samp{"sasl"}.
28150 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
28151 Authentication scheme for TLS sockets. TLS sockets already have
28152 encryption provided by the TLS layer, and limited authentication is done
28155 It is possible to make use of any SASL authentication mechanism as well,
28156 by using 'sasl' for this option
28158 Defaults to @samp{"none"}.
28162 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
28163 API access control scheme.
28165 By default an authenticated user is allowed access to all APIs. Access
28166 drivers can place restrictions on this.
28168 Defaults to @samp{()}.
28172 @deftypevr {@code{libvirt-configuration} parameter} string key-file
28173 Server key file path. If set to an empty string, then no private key is
28176 Defaults to @samp{""}.
28180 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
28181 Server key file path. If set to an empty string, then no certificate is
28184 Defaults to @samp{""}.
28188 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
28189 Server key file path. If set to an empty string, then no CA certificate
28192 Defaults to @samp{""}.
28196 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
28197 Certificate revocation list path. If set to an empty string, then no
28200 Defaults to @samp{""}.
28204 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
28205 Disable verification of our own server certificates.
28207 When libvirtd starts it performs some sanity checks against its own
28210 Defaults to @samp{#f}.
28214 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
28215 Disable verification of client certificates.
28217 Client certificate verification is the primary authentication mechanism.
28218 Any client which does not present a certificate signed by the CA will be
28221 Defaults to @samp{#f}.
28225 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
28226 Whitelist of allowed x509 Distinguished Name.
28228 Defaults to @samp{()}.
28232 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
28233 Whitelist of allowed SASL usernames. The format for username depends on
28234 the SASL authentication mechanism.
28236 Defaults to @samp{()}.
28240 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
28241 Override the compile time default TLS priority string. The default is
28242 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
28243 is desired for libvirt to deviate from the global default settings.
28245 Defaults to @samp{"NORMAL"}.
28249 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
28250 Maximum number of concurrent client connections to allow over all
28253 Defaults to @samp{5000}.
28257 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
28258 Maximum length of queue of connections waiting to be accepted by the
28259 daemon. Note, that some protocols supporting retransmission may obey
28260 this so that a later reattempt at connection succeeds.
28262 Defaults to @samp{1000}.
28266 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
28267 Maximum length of queue of accepted but not yet authenticated clients.
28268 Set this to zero to turn this feature off
28270 Defaults to @samp{20}.
28274 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
28275 Number of workers to start up initially.
28277 Defaults to @samp{5}.
28281 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
28282 Maximum number of worker threads.
28284 If the number of active clients exceeds @code{min-workers}, then more
28285 threads are spawned, up to max_workers limit. Typically you'd want
28286 max_workers to equal maximum number of clients allowed.
28288 Defaults to @samp{20}.
28292 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
28293 Number of priority workers. If all workers from above pool are stuck,
28294 some calls marked as high priority (notably domainDestroy) can be
28295 executed in this pool.
28297 Defaults to @samp{5}.
28301 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
28302 Total global limit on concurrent RPC calls.
28304 Defaults to @samp{20}.
28308 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
28309 Limit on concurrent requests from a single client connection. To avoid
28310 one client monopolizing the server this should be a small fraction of
28311 the global max_requests and max_workers parameter.
28313 Defaults to @samp{5}.
28317 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
28318 Same as @code{min-workers} but for the admin interface.
28320 Defaults to @samp{1}.
28324 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
28325 Same as @code{max-workers} but for the admin interface.
28327 Defaults to @samp{5}.
28331 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
28332 Same as @code{max-clients} but for the admin interface.
28334 Defaults to @samp{5}.
28338 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
28339 Same as @code{max-queued-clients} but for the admin interface.
28341 Defaults to @samp{5}.
28345 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
28346 Same as @code{max-client-requests} but for the admin interface.
28348 Defaults to @samp{5}.
28352 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
28353 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
28355 Defaults to @samp{3}.
28359 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
28362 A filter allows to select a different logging level for a given category
28363 of logs. The format for a filter is one of:
28374 where @code{name} is a string which is matched against the category
28375 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
28376 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
28377 name in the filter can be a substring of the full category name, in
28378 order to match multiple similar categories), the optional @samp{"+"}
28379 prefix tells libvirt to log stack trace for each message matching name,
28380 and @code{x} is the minimal level where matching messages should be
28398 Multiple filters can be defined in a single filters statement, they just
28399 need to be separated by spaces.
28401 Defaults to @samp{"3:remote 4:event"}.
28405 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
28408 An output is one of the places to save logging information. The format
28409 for an output can be:
28413 output goes to stderr
28415 @item x:syslog:name
28416 use syslog for the output and use the given name as the ident
28418 @item x:file:file_path
28419 output to a file, with the given filepath
28422 output to journald logging system
28426 In all case the x prefix is the minimal level, acting as a filter
28443 Multiple outputs can be defined, they just need to be separated by
28446 Defaults to @samp{"3:stderr"}.
28450 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
28451 Allows usage of the auditing subsystem to be altered
28455 0: disable all auditing
28458 1: enable auditing, only if enabled on host
28461 2: enable auditing, and exit if disabled on host.
28465 Defaults to @samp{1}.
28469 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
28470 Send audit messages via libvirt logging infrastructure.
28472 Defaults to @samp{#f}.
28476 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
28477 Host UUID@. UUID must not have all digits be the same.
28479 Defaults to @samp{""}.
28483 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
28484 Source to read host UUID.
28488 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
28491 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
28495 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
28498 Defaults to @samp{"smbios"}.
28502 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
28503 A keepalive message is sent to a client after @code{keepalive_interval}
28504 seconds of inactivity to check if the client is still responding. If
28505 set to -1, libvirtd will never send keepalive requests; however clients
28506 can still send them and the daemon will send responses.
28508 Defaults to @samp{5}.
28512 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
28513 Maximum number of keepalive messages that are allowed to be sent to the
28514 client without getting any response before the connection is considered
28517 In other words, the connection is automatically closed approximately
28518 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
28519 the last message received from the client. When @code{keepalive-count}
28520 is set to 0, connections will be automatically closed after
28521 @code{keepalive-interval} seconds of inactivity without sending any
28522 keepalive messages.
28524 Defaults to @samp{5}.
28528 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
28529 Same as above but for admin interface.
28531 Defaults to @samp{5}.
28535 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
28536 Same as above but for admin interface.
28538 Defaults to @samp{5}.
28542 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
28543 Timeout for Open vSwitch calls.
28545 The @code{ovs-vsctl} utility is used for the configuration and its
28546 timeout option is set by default to 5 seconds to avoid potential
28547 infinite waits blocking libvirt.
28549 Defaults to @samp{5}.
28553 @c %end of autogenerated docs
28555 @subsubheading Virtlog daemon
28556 The virtlogd service is a server side daemon component of libvirt that is
28557 used to manage logs from virtual machine consoles.
28559 This daemon is not used directly by libvirt client applications, rather it
28560 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
28561 standalone daemon, the main @code{libvirtd} daemon can be restarted without
28562 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
28563 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
28565 @deffn {Scheme Variable} virtlog-service-type
28566 This is the type of the virtlog daemon.
28567 Its value must be a @code{virtlog-configuration}.
28570 (service virtlog-service-type
28571 (virtlog-configuration
28572 (max-clients 1000)))
28576 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
28577 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
28579 Defaults to @samp{3}.
28583 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
28586 A filter allows to select a different logging level for a given category
28587 of logs The format for a filter is one of:
28598 where @code{name} is a string which is matched against the category
28599 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
28600 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
28601 be a substring of the full category name, in order to match multiple
28602 similar categories), the optional "+" prefix tells libvirt to log stack
28603 trace for each message matching name, and @code{x} is the minimal level
28604 where matching messages should be logged:
28621 Multiple filters can be defined in a single filters statement, they just
28622 need to be separated by spaces.
28624 Defaults to @samp{"3:remote 4:event"}.
28628 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
28631 An output is one of the places to save logging information The format
28632 for an output can be:
28636 output goes to stderr
28638 @item x:syslog:name
28639 use syslog for the output and use the given name as the ident
28641 @item x:file:file_path
28642 output to a file, with the given filepath
28645 output to journald logging system
28649 In all case the x prefix is the minimal level, acting as a filter
28666 Multiple outputs can be defined, they just need to be separated by
28669 Defaults to @samp{"3:stderr"}.
28673 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
28674 Maximum number of concurrent client connections to allow over all
28677 Defaults to @samp{1024}.
28681 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
28682 Maximum file size before rolling over.
28684 Defaults to @samp{2MB}
28688 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
28689 Maximum number of backup files to keep.
28691 Defaults to @samp{3}
28695 @anchor{transparent-emulation-qemu}
28696 @subsubheading Transparent Emulation with QEMU
28699 @cindex @code{binfmt_misc}
28700 @code{qemu-binfmt-service-type} provides support for transparent
28701 emulation of program binaries built for different architectures---e.g.,
28702 it allows you to transparently execute an ARMv7 program on an x86_64
28703 machine. It achieves this by combining the @uref{https://www.qemu.org,
28704 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
28705 This feature only allows you to emulate GNU/Linux on a different
28706 architecture, but see below for GNU/Hurd support.
28708 @defvr {Scheme Variable} qemu-binfmt-service-type
28709 This is the type of the QEMU/binfmt service for transparent emulation.
28710 Its value must be a @code{qemu-binfmt-configuration} object, which
28711 specifies the QEMU package to use as well as the architecture we want to
28715 (service qemu-binfmt-service-type
28716 (qemu-binfmt-configuration
28717 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
28720 In this example, we enable transparent emulation for the ARM and aarch64
28721 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
28722 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
28723 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
28726 @deftp {Data Type} qemu-binfmt-configuration
28727 This is the configuration for the @code{qemu-binfmt} service.
28730 @item @code{platforms} (default: @code{'()})
28731 The list of emulated QEMU platforms. Each item must be a @dfn{platform
28732 object} as returned by @code{lookup-qemu-platforms} (see below).
28734 For example, let's suppose you're on an x86_64 machine and you have this
28738 (service qemu-binfmt-service-type
28739 (qemu-binfmt-configuration
28740 (platforms (lookup-qemu-platforms "arm"))))
28746 guix build -s armhf-linux inkscape
28750 and it will build Inkscape for ARMv7 @emph{as if it were a native
28751 build}, transparently using QEMU to emulate the ARMv7 CPU@. Pretty handy
28752 if you'd like to test a package build for an architecture you don't have
28755 @item @code{qemu} (default: @code{qemu})
28756 The QEMU package to use.
28760 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
28761 Return the list of QEMU platform objects corresponding to
28762 @var{platforms}@dots{}. @var{platforms} must be a list of strings
28763 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
28764 @code{"mips64el"}, and so on.
28767 @deffn {Scheme Procedure} qemu-platform? @var{obj}
28768 Return true if @var{obj} is a platform object.
28771 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
28772 Return the name of @var{platform}---a string such as @code{"arm"}.
28776 @subsubheading The Hurd in a Virtual Machine
28778 @cindex @code{hurd}
28782 Service @code{hurd-vm} provides support for running GNU/Hurd in a
28783 virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
28784 to be used on GNU/Linux and the given GNU/Hurd operating system
28785 configuration is cross-compiled. The virtual machine is a Shepherd
28786 service that can be referred to by the names @code{hurd-vm} and
28787 @code{childhurd} and be controlled with commands such as:
28791 herd stop childhurd
28794 When the service is running, you can view its console by connecting to
28795 it with a VNC client, for example with:
28798 guix environment --ad-hoc tigervnc-client -- \
28799 vncviewer localhost:5900
28802 The default configuration (see @code{hurd-vm-configuration} below)
28803 spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
28804 (the virtual machine emulator) redirects to port 10222 on the host.
28805 Thus, you can connect over SSH to the childhurd with:
28808 ssh root@@localhost -p 10022
28811 The childhurd is volatile and stateless: it starts with a fresh root
28812 file system every time you restart it. By default though, all the files
28813 under @file{/etc/childhurd} on the host are copied as is to the root
28814 file system of the childhurd when it boots. This allows you to
28815 initialize ``secrets'' inside the VM: SSH host keys, authorized
28816 substitute keys, and so on---see the explanation of @code{secret-root}
28819 @defvr {Scheme Variable} hurd-vm-service-type
28820 This is the type of the Hurd in a Virtual Machine service. Its value
28821 must be a @code{hurd-vm-configuration} object, which specifies the
28822 operating system (@pxref{operating-system Reference}) and the disk size
28823 for the Hurd Virtual Machine, the QEMU package to use as well as the
28824 options for running it.
28829 (service hurd-vm-service-type
28830 (hurd-vm-configuration
28831 (disk-size (* 5000 (expt 2 20))) ;5G
28832 (memory-size 1024))) ;1024MiB
28835 would create a disk image big enough to build GNU@tie{}Hello, with some
28839 @deftp {Data Type} hurd-vm-configuration
28840 The data type representing the configuration for
28841 @code{hurd-vm-service-type}.
28844 @item @code{os} (default: @var{%hurd-vm-operating-system})
28845 The operating system to instantiate. This default is bare-bones with a
28846 permissive OpenSSH secure shell daemon listening on port 2222
28847 (@pxref{Networking Services, @code{openssh-service-type}}).
28849 @item @code{qemu} (default: @code{qemu-minimal})
28850 The QEMU package to use.
28852 @item @code{image} (default: @var{hurd-vm-disk-image})
28853 The procedure used to build the disk-image built from this
28856 @item @code{disk-size} (default: @code{'guess})
28857 The size of the disk image.
28859 @item @code{memory-size} (default: @code{512})
28860 The memory size of the Virtual Machine in mebibytes.
28862 @item @code{options} (default: @code{'("--snapshot")})
28863 The extra options for running QEMU.
28865 @item @code{id} (default: @code{#f})
28866 If set, a non-zero positive integer used to parameterize Childhurd
28867 instances. It is appended to the service's name,
28868 e.g. @code{childhurd1}.
28870 @item @code{net-options} (default: @var{hurd-vm-net-options})
28871 The procedure used to produce the list of QEMU networking options.
28873 By default, it produces
28876 '("--device" "rtl8139,netdev=net0"
28877 "--netdev" "user,id=net0\
28878 ,hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004\
28879 ,hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222\
28880 ,hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900")
28883 with forwarded ports:
28886 @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
28887 @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
28888 @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
28891 @item @code{secret-root} (default: @file{/etc/childhurd})
28892 The root directory with out-of-band secrets to be installed into the
28893 childhurd once it runs. Childhurds are volatile which means that on
28894 every startup, secrets such as the SSH host keys and Guix signing key
28897 If the @file{/etc/childhurd} directory does not exist, the
28898 @code{secret-service} running in the Childhurd will be sent an empty
28901 By default, the service automatically populates @file{/etc/childhurd}
28902 with the following non-volatile secrets, unless they already exist:
28905 /etc/childhurd/etc/guix/acl
28906 /etc/childhurd/etc/guix/signing-key.pub
28907 /etc/childhurd/etc/guix/signing-key.sec
28908 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
28909 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
28910 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
28911 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
28914 These files are automatically sent to the guest Hurd VM when it boots,
28915 including permissions.
28917 @cindex childhurd, offloading
28918 @cindex Hurd, offloading
28919 Having these files in place means that only a couple of things are
28920 missing to allow the host to offload @code{i586-gnu} builds to the
28925 Authorizing the childhurd's key on the host so that the host accepts
28926 build results coming from the childhurd, which can be done like so:
28929 guix archive --authorize < \
28930 /etc/childhurd/etc/guix/signing-key.pub
28934 Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
28938 We're working towards making that happen automatically---get in touch
28939 with us at @email{guix-devel@@gnu.org} to discuss it!
28943 Note that by default the VM image is volatile, i.e., once stopped the
28944 contents are lost. If you want a stateful image instead, override the
28945 configuration's @code{image} and @code{options} without
28946 the @code{--snapshot} flag using something along these lines:
28949 (service hurd-vm-service-type
28950 (hurd-vm-configuration
28951 (image (const "/out/of/store/writable/hurd.img"))
28955 @subsubheading Ganeti
28960 This service is considered experimental. Configuration options may be changed
28961 in a backwards-incompatible manner, and not all features have been thorougly
28962 tested. Users of this service are encouraged to share their experience at
28963 @email{guix-devel@@gnu.org}.
28966 Ganeti is a virtual machine management system. It is designed to keep virtual
28967 machines running on a cluster of servers even in the event of hardware failures,
28968 and to make maintenance and recovery tasks easy. It consists of multiple
28969 services which are described later in this section. In addition to the Ganeti
28970 service, you will need the OpenSSH service (@pxref{Networking Services,
28971 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
28972 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
28973 and address (or use a DNS server).
28975 All nodes participating in a Ganeti cluster should have the same Ganeti and
28976 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
28977 cluster node that supports multiple storage backends, and installs the
28978 @code{debootstrap} and @code{guix} @dfn{OS providers}:
28981 (use-package-modules virtualization)
28982 (use-service-modules base ganeti networking ssh)
28985 (host-name "node1")
28986 (hosts-file (plain-file "hosts" (format #f "
28987 127.0.0.1 localhost
28990 192.168.1.200 ganeti.example.com
28991 192.168.1.201 node1.example.com node1
28992 192.168.1.202 node2.example.com node2
28995 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
28996 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
28997 (packages (append (map specification->package
28998 '("qemu" "lvm2" "drbd-utils" "ceph"
28999 ;; Add the debootstrap and guix OS providers.
29000 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
29003 (append (list (static-networking-service "eth0" "192.168.1.201"
29004 #:netmask "255.255.255.0"
29005 #:gateway "192.168.1.254"
29006 #:name-servers '("192.168.1.252"
29009 ;; Ganeti uses SSH to communicate between nodes.
29010 (service openssh-service-type
29011 (openssh-configuration
29012 (permit-root-login 'without-password)))
29014 (service ganeti-service-type
29015 (ganeti-configuration
29016 ;; This list specifies allowed file system paths
29017 ;; for storing virtual machine images.
29018 (file-storage-paths '("/srv/ganeti/file-storage"))
29019 ;; This variable configures a single "variant" for
29020 ;; both Debootstrap and Guix that works with KVM.
29021 (os %default-ganeti-os))))
29025 Users are advised to read the
29026 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
29027 administrators guide} to learn about the various cluster options and
29028 day-to-day operations. There is also a
29029 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
29030 describing how to configure and initialize a small cluster.
29032 @defvr {Scheme Variable} ganeti-service-type
29033 This is a service type that includes all the various services that Ganeti
29036 Its value is a @code{ganeti-configuration} object that defines the package
29037 to use for CLI operations, as well as configuration for the various daemons.
29038 Allowed file storage paths and available guest operating systems are also
29039 configured through this data type.
29042 @deftp {Data Type} ganeti-configuration
29043 The @code{ganeti} service takes the following configuration options:
29046 @item @code{ganeti} (default: @code{ganeti})
29047 The @code{ganeti} package to use. It will be installed to the system profile
29048 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
29049 that the value specified here does not affect the other services as each refer
29050 to a specific @code{ganeti} package (see below).
29052 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
29053 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
29054 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
29055 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
29056 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
29057 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
29058 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
29059 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
29060 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
29061 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
29063 These options control the various daemons and cron jobs that are distributed
29064 with Ganeti. The possible values for these are described in detail below.
29065 To override a setting, you must use the configuration type for that service:
29068 (service ganeti-service-type
29069 (ganeti-configuration
29070 (rapi-configuration
29071 (ganeti-rapi-configuration
29072 (interface "eth1"))))
29073 (watcher-configuration
29074 (ganeti-watcher-configuration
29075 (rapi-ip "10.0.0.1"))))
29078 @item @code{file-storage-paths} (default: @code{'()})
29079 List of allowed directories for file storage backend.
29081 @item @code{os} (default: @code{%default-ganeti-os})
29082 List of @code{<ganeti-os>} records.
29085 In essence @code{ganeti-service-type} is shorthand for declaring each service
29089 (service ganeti-noded-service-type)
29090 (service ganeti-confd-service-type)
29091 (service ganeti-wconfd-service-type)
29092 (service ganeti-luxid-service-type)
29093 (service ganeti-kvmd-service-type)
29094 (service ganeti-mond-service-type)
29095 (service ganeti-metad-service-type)
29096 (service ganeti-watcher-service-type)
29097 (service ganeti-cleaner-service-type)
29100 Plus a service extension for @code{etc-service-type} that configures the file
29101 storage backend and OS variants.
29105 @deftp {Data Type} ganeti-os
29106 This data type is suitable for passing to the @code{os} parameter of
29107 @code{ganeti-configuration}. It takes the following parameters:
29111 The name for this OS provider. It is only used to specify where the
29112 configuration ends up. Setting it to ``debootstrap'' will create
29113 @file{/etc/ganeti/instance-debootstrap}.
29115 @item @code{extension}
29116 The file extension for variants of this OS type. For example
29117 @file{.conf} or @file{.scm}.
29119 @item @code{variants} (default: @code{'()})
29120 List of @code{ganeti-os-variant} objects for this OS.
29125 @deftp {Data Type} ganeti-os-variant
29126 This is the data type for a Ganeti OS variant. It takes the following
29131 The name of this variant.
29133 @item @code{configuration}
29134 A configuration file for this variant.
29138 @defvr {Scheme Variable} %default-debootstrap-hooks
29139 This variable contains hooks to configure networking and the GRUB bootloader.
29142 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
29143 This variable contains a list of packages suitable for a fully-virtualized guest.
29146 @deftp {Data Type} debootstrap-configuration
29148 This data type creates configuration files suitable for the debootstrap OS provider.
29151 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
29152 When not @code{#f}, this must be a G-expression that specifies a directory with
29153 scripts that will run when the OS is installed. It can also be a list of
29154 @code{(name . file-like)} pairs. For example:
29157 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
29160 That will create a directory with one executable named @code{99-hello-world}
29161 and run it every time this variant is installed. If set to @code{#f}, hooks
29162 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
29163 @item @code{proxy} (default: @code{#f})
29164 Optional HTTP proxy to use.
29165 @item @code{mirror} (default: @code{#f})
29166 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
29167 The default varies depending on the distribution.
29168 @item @code{arch} (default: @code{#f})
29169 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
29170 on an AArch64 host. Default is to use the current system architecture.
29171 @item @code{suite} (default: @code{"stable"})
29172 When set, this must be a Debian distribution ``suite'' such as @code{buster}
29173 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
29174 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
29175 List of extra packages that will get installed by dpkg in addition
29176 to the minimal system.
29177 @item @code{components} (default: @code{#f})
29178 When set, must be a list of Debian repository ``components''. For example
29179 @code{'("main" "contrib")}.
29180 @item @code{generate-cache?} (default: @code{#t})
29181 Whether to automatically cache the generated debootstrap archive.
29182 @item @code{clean-cache} (default: @code{14})
29183 Discard the cache after this amount of days. Use @code{#f} to never
29185 @item @code{partition-style} (default: @code{'msdos})
29186 The type of partition to create. When set, it must be one of
29187 @code{'msdos}, @code{'none} or a string.
29188 @item @code{partition-alignment} (default: @code{2048})
29189 Alignment of the partition in sectors.
29193 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
29194 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
29195 takes two parameters: a name and a @code{debootstrap-configuration} object.
29198 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
29199 This is a helper procedure that creates a @code{ganeti-os} record. It takes
29200 a list of variants created with @code{debootstrap-variant}.
29203 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
29204 This is a helper procedure that creates a @code{ganeti-os-variant} record for
29205 use with the Guix OS provider. It takes a name and a G-expression that returns
29206 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
29207 Guix System configuration.
29210 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
29211 This is a helper procedure that creates a @code{ganeti-os} record. It
29212 takes a list of variants produced by @code{guix-variant}.
29215 @defvr {Scheme Variable} %default-debootstrap-variants
29216 This is a convenience variable to make the debootstrap provider work
29217 ``out of the box'' without users having to declare variants manually. It
29218 contains a single debootstrap variant with the default configuration:
29221 (list (debootstrap-variant
29223 (debootstrap-configuration)))
29227 @defvr {Scheme Variable} %default-guix-variants
29228 This is a convenience variable to make the Guix OS provider work without
29229 additional configuration. It creates a virtual machine that has an SSH
29230 server, a serial console, and authorizes the Ganeti hosts SSH keys.
29233 (list (guix-variant
29235 (file-append ganeti-instance-guix
29236 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
29240 Users can implement support for OS providers unbeknownst to Guix by extending
29241 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
29247 (extension ".conf")
29249 (list (ganeti-os-variant
29251 (configuration (plain-file "bar" "this is fine"))))))
29254 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
29255 to a file in the store with contents @code{this is fine}. It also creates
29256 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
29258 Obviously this may not work for all OS providers out there. If you find the
29259 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
29261 The rest of this section documents the various services that are included by
29262 @code{ganeti-service-type}.
29264 @defvr {Scheme Variable} ganeti-noded-service-type
29265 @command{ganeti-noded} is the daemon responsible for node-specific functions
29266 within the Ganeti system. The value of this service must be a
29267 @code{ganeti-noded-configuration} object.
29270 @deftp {Data Type} ganeti-noded-configuration
29271 This is the configuration for the @code{ganeti-noded} service.
29274 @item @code{ganeti} (default: @code{ganeti})
29275 The @code{ganeti} package to use for this service.
29277 @item @code{port} (default: @code{1811})
29278 The TCP port on which the node daemon listens for network requests.
29280 @item @code{address} (default: @code{"0.0.0.0"})
29281 The network address that the daemon will bind to. The default address means
29282 bind to all available addresses.
29284 @item @code{interface} (default: @code{#f})
29285 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
29286 that the daemon will bind to.
29288 @item @code{max-clients} (default: @code{20})
29289 This sets a limit on the maximum number of simultaneous client connections
29290 that the daemon will handle. Connections above this count are accepted, but
29291 no responses will be sent until enough connections have closed.
29293 @item @code{ssl?} (default: @code{#t})
29294 Whether to use SSL/TLS to encrypt network communications. The certificate
29295 is automatically provisioned by the cluster and can be rotated with
29296 @command{gnt-cluster renew-crypto}.
29298 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
29299 This can be used to provide a specific encryption key for TLS communications.
29301 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
29302 This can be used to provide a specific certificate for TLS communications.
29304 @item @code{debug?} (default: @code{#f})
29305 When true, the daemon performs additional logging for debugging purposes.
29306 Note that this will leak encryption details to the log files, use with caution.
29311 @defvr {Scheme Variable} ganeti-confd-service-type
29312 @command{ganeti-confd} answers queries related to the configuration of a
29313 Ganeti cluster. The purpose of this daemon is to have a highly available
29314 and fast way to query cluster configuration values. It is automatically
29315 active on all @dfn{master candidates}. The value of this service must be a
29316 @code{ganeti-confd-configuration} object.
29320 @deftp {Data Type} ganeti-confd-configuration
29321 This is the configuration for the @code{ganeti-confd} service.
29324 @item @code{ganeti} (default: @code{ganeti})
29325 The @code{ganeti} package to use for this service.
29327 @item @code{port} (default: @code{1814})
29328 The UDP port on which to listen for network requests.
29330 @item @code{address} (default: @code{"0.0.0.0"})
29331 Network address that the daemon will bind to.
29333 @item @code{debug?} (default: @code{#f})
29334 When true, the daemon performs additional logging for debugging purposes.
29339 @defvr {Scheme Variable} ganeti-wconfd-service-type
29340 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
29341 about the cluster configuration and is the only entity that can accept
29342 changes to it. All jobs that need to modify the configuration will do so
29343 by sending appropriate requests to this daemon. It only runs on the
29344 @dfn{master node} and will automatically disable itself on other nodes.
29346 The value of this service must be a
29347 @code{ganeti-wconfd-configuration} object.
29350 @deftp {Data Type} ganeti-wconfd-configuration
29351 This is the configuration for the @code{ganeti-wconfd} service.
29354 @item @code{ganeti} (default: @code{ganeti})
29355 The @code{ganeti} package to use for this service.
29357 @item @code{no-voting?} (default: @code{#f})
29358 The daemon will refuse to start if the majority of cluster nodes does not
29359 agree that it is running on the master node. Set to @code{#t} to start
29360 even if a quorum can not be reached (dangerous, use with caution).
29362 @item @code{debug?} (default: @code{#f})
29363 When true, the daemon performs additional logging for debugging purposes.
29368 @defvr {Scheme Variable} ganeti-luxid-service-type
29369 @command{ganeti-luxid} is a daemon used to answer queries related to the
29370 configuration and the current live state of a Ganeti cluster. Additionally,
29371 it is the authoritative daemon for the Ganeti job queue. Jobs can be
29372 submitted via this daemon and it schedules and starts them.
29374 It takes a @code{ganeti-luxid-configuration} object.
29377 @deftp {Data Type} ganeti-luxid-configuration
29378 This is the configuration for the @code{ganeti-wconfd} service.
29381 @item @code{ganeti} (default: @code{ganeti})
29382 The @code{ganeti} package to use for this service.
29384 @item @code{no-voting?} (default: @code{#f})
29385 The daemon will refuse to start if it cannot verify that the majority of
29386 cluster nodes believes that it is running on the master node. Set to
29387 @code{#t} to ignore such checks and start anyway (this can be dangerous).
29389 @item @code{debug?} (default: @code{#f})
29390 When true, the daemon performs additional logging for debugging purposes.
29395 @defvr {Scheme Variable} ganeti-rapi-service-type
29396 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
29397 the master node and can be used to perform cluster actions programmatically
29398 via a JSON-based RPC protocol.
29400 Most query operations are allowed without authentication (unless
29401 @var{require-authentication?} is set), whereas write operations require
29402 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
29403 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
29404 API documentation} for more information.
29406 The value of this service must be a @code{ganeti-rapi-configuration} object.
29409 @deftp {Data Type} ganeti-rapi-configuration
29410 This is the configuration for the @code{ganeti-rapi} service.
29413 @item @code{ganeti} (default: @code{ganeti})
29414 The @code{ganeti} package to use for this service.
29416 @item @code{require-authentication?} (default: @code{#f})
29417 Whether to require authentication even for read-only operations.
29419 @item @code{port} (default: @code{5080})
29420 The TCP port on which to listen to API requests.
29422 @item @code{address} (default: @code{"0.0.0.0"})
29423 The network address that the service will bind to. By default it listens
29424 on all configured addresses.
29426 @item @code{interface} (default: @code{#f})
29427 When set, it must specify a specific network interface such as @code{eth0}
29428 that the daemon will bind to.
29430 @item @code{max-clients} (default: @code{20})
29431 The maximum number of simultaneous client requests to handle. Further
29432 connections are allowed, but no responses are sent until enough connections
29435 @item @code{ssl?} (default: @code{#t})
29436 Whether to use SSL/TLS encryption on the RAPI port.
29438 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
29439 This can be used to provide a specific encryption key for TLS communications.
29441 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
29442 This can be used to provide a specific certificate for TLS communications.
29444 @item @code{debug?} (default: @code{#f})
29445 When true, the daemon performs additional logging for debugging purposes.
29446 Note that this will leak encryption details to the log files, use with caution.
29451 @defvr {Scheme Variable} ganeti-kvmd-service-type
29452 @command{ganeti-kvmd} is responsible for determining whether a given KVM
29453 instance was shut down by an administrator or a user. Normally Ganeti will
29454 restart an instance that was not stopped through Ganeti itself. If the
29455 cluster option @code{user_shutdown} is true, this daemon monitors the
29456 @code{QMP} socket provided by QEMU and listens for shutdown events, and
29457 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
29458 it shuts down gracefully by itself.
29460 It takes a @code{ganeti-kvmd-configuration} object.
29463 @deftp {Data Type} ganeti-kvmd-configuration
29466 @item @code{ganeti} (default: @code{ganeti})
29467 The @code{ganeti} package to use for this service.
29469 @item @code{debug?} (default: @code{#f})
29470 When true, the daemon performs additional logging for debugging purposes.
29475 @defvr {Scheme Variable} ganeti-mond-service-type
29476 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
29477 functionality. It is responsible for running data collectors and publish the
29478 collected information through a HTTP interface.
29480 It takes a @code{ganeti-mond-configuration} object.
29483 @deftp {Data Type} ganeti-mond-configuration
29486 @item @code{ganeti} (default: @code{ganeti})
29487 The @code{ganeti} package to use for this service.
29489 @item @code{port} (default: @code{1815})
29490 The port on which the daemon will listen.
29492 @item @code{address} (default: @code{"0.0.0.0"})
29493 The network address that the daemon will bind to. By default it binds to all
29494 available interfaces.
29496 @item @code{debug?} (default: @code{#f})
29497 When true, the daemon performs additional logging for debugging purposes.
29502 @defvr {Scheme Variable} ganeti-metad-service-type
29503 @command{ganeti-metad} is an optional daemon that can be used to provide
29504 information about the cluster to instances or OS install scripts.
29506 It takes a @code{ganeti-metad-configuration} object.
29509 @deftp {Data Type} ganeti-metad-configuration
29512 @item @code{ganeti} (default: @code{ganeti})
29513 The @code{ganeti} package to use for this service.
29515 @item @code{port} (default: @code{80})
29516 The port on which the daemon will listen.
29518 @item @code{address} (default: @code{#f})
29519 If set, the daemon will bind to this address only. If left unset, the behavior
29520 depends on the cluster configuration.
29522 @item @code{debug?} (default: @code{#f})
29523 When true, the daemon performs additional logging for debugging purposes.
29528 @defvr {Scheme Variable} ganeti-watcher-service-type
29529 @command{ganeti-watcher} is a script designed to run periodically and ensure
29530 the health of a cluster. It will automatically restart instances that have
29531 stopped without Ganeti's consent, and repairs DRBD links in case a node has
29532 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
29533 that are not running. If the cluster parameter @code{ensure_node_health}
29534 is set, the watcher will also shutdown instances and DRBD devices if the
29535 node it is running on is declared offline by known master candidates.
29537 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
29539 The service takes a @code{ganeti-watcher-configuration} object.
29542 @deftp {Data Type} ganeti-watcher-configuration
29545 @item @code{ganeti} (default: @code{ganeti})
29546 The @code{ganeti} package to use for this service.
29548 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
29549 How often to run the script. The default is every five minutes.
29551 @item @code{rapi-ip} (default: @code{#f})
29552 This option needs to be specified only if the RAPI daemon is configured to use
29553 a particular interface or address. By default the cluster address is used.
29555 @item @code{job-age} (default: @code{(* 6 3600)})
29556 Archive cluster jobs older than this age, specified in seconds. The default
29557 is 6 hours. This keeps @command{gnt-job list} manageable.
29559 @item @code{verify-disks?} (default: @code{#t})
29560 If this is @code{#f}, the watcher will not try to repair broken DRBD links
29561 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
29564 @item @code{debug?} (default: @code{#f})
29565 When @code{#t}, the script performs additional logging for debugging purposes.
29570 @defvr {Scheme Variable} ganeti-cleaner-service-type
29571 @command{ganeti-cleaner} is a script designed to run periodically and remove
29572 old files from the cluster. This service type controls two @dfn{cron jobs}:
29573 one intended for the master node that permanently purges old cluster jobs,
29574 and one intended for every node that removes expired X509 certificates, keys,
29575 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
29576 it is safe to include even on non-master nodes as it will disable itself as
29579 It takes a @code{ganeti-cleaner-configuration} object.
29582 @deftp {Data Type} ganeti-cleaner-configuration
29585 @item @code{ganeti} (default: @code{ganeti})
29586 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
29588 @item @code{master-schedule} (default: @code{"45 1 * * *"})
29589 How often to run the master cleaning job. The default is once per day, at
29592 @item @code{node-schedule} (default: @code{"45 2 * * *"})
29593 How often to run the node cleaning job. The default is once per day, at
29599 @node Version Control Services
29600 @subsection Version Control Services
29602 The @code{(gnu services version-control)} module provides a service to
29603 allow remote access to local Git repositories. There are three options:
29604 the @code{git-daemon-service}, which provides access to repositories via
29605 the @code{git://} unsecured TCP-based protocol, extending the
29606 @code{nginx} web server to proxy some requests to
29607 @code{git-http-backend}, or providing a web interface with
29608 @code{cgit-service-type}.
29610 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
29612 Return a service that runs @command{git daemon}, a simple TCP server to
29613 expose repositories over the Git protocol for anonymous access.
29615 The optional @var{config} argument should be a
29616 @code{<git-daemon-configuration>} object, by default it allows read-only
29617 access to exported@footnote{By creating the magic file
29618 @file{git-daemon-export-ok} in the repository directory.} repositories under
29623 @deftp {Data Type} git-daemon-configuration
29624 Data type representing the configuration for @code{git-daemon-service}.
29627 @item @code{package} (default: @code{git})
29628 Package object of the Git distributed version control system.
29630 @item @code{export-all?} (default: @code{#f})
29631 Whether to allow access for all Git repositories, even if they do not
29632 have the @file{git-daemon-export-ok} file.
29634 @item @code{base-path} (default: @file{/srv/git})
29635 Whether to remap all the path requests as relative to the given path.
29636 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
29637 @samp{example.com}, then if you later try to pull
29638 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
29639 path as @file{/srv/git/hello.git}.
29641 @item @code{user-path} (default: @code{#f})
29642 Whether to allow @code{~user} notation to be used in requests. When
29643 specified with empty string, requests to
29644 @indicateurl{git://host/~alice/foo} is taken as a request to access
29645 @code{foo} repository in the home directory of user @code{alice}. If
29646 @code{(user-path "@var{path}")} is specified, the same request is taken
29647 as a request to access @file{@var{path}/foo} repository in the home
29648 directory of user @code{alice}.
29650 @item @code{listen} (default: @code{'()})
29651 Whether to listen on specific IP addresses or hostnames, defaults to
29654 @item @code{port} (default: @code{#f})
29655 Whether to listen on an alternative port, which defaults to 9418.
29657 @item @code{whitelist} (default: @code{'()})
29658 If not empty, only allow access to this list of directories.
29660 @item @code{extra-options} (default: @code{'()})
29661 Extra options will be passed to @command{git daemon}, please run
29662 @command{man git-daemon} for more information.
29667 The @code{git://} protocol lacks authentication. When you pull from a
29668 repository fetched via @code{git://}, you don't know whether the data you
29669 receive was modified or is even coming from the specified host, and your
29670 connection is subject to eavesdropping. It's better to use an authenticated
29671 and encrypted transport, such as @code{https}. Although Git allows you
29672 to serve repositories using unsophisticated file-based web servers,
29673 there is a faster protocol implemented by the @code{git-http-backend}
29674 program. This program is the back-end of a proper Git web service. It
29675 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
29676 on running the necessary @code{fcgiwrap} daemon.
29678 Guix has a separate configuration data type for serving Git repositories
29681 @deftp {Data Type} git-http-configuration
29682 Data type representing the configuration for a future
29683 @code{git-http-service-type}; can currently be used to configure Nginx
29684 through @code{git-http-nginx-location-configuration}.
29687 @item @code{package} (default: @var{git})
29688 Package object of the Git distributed version control system.
29690 @item @code{git-root} (default: @file{/srv/git})
29691 Directory containing the Git repositories to expose to the world.
29693 @item @code{export-all?} (default: @code{#f})
29694 Whether to expose access for all Git repositories in @var{git-root},
29695 even if they do not have the @file{git-daemon-export-ok} file.
29697 @item @code{uri-path} (default: @samp{/git/})
29698 Path prefix for Git access. With the default @samp{/git/} prefix, this
29699 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
29700 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
29701 with this prefix are not passed on to this Git instance.
29703 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
29704 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
29709 There is no @code{git-http-service-type}, currently; instead you can
29710 create an @code{nginx-location-configuration} from a
29711 @code{git-http-configuration} and then add that location to a web
29714 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
29715 [config=(git-http-configuration)]
29716 Compute an @code{nginx-location-configuration} that corresponds to the
29717 given Git http configuration. An example nginx service definition to
29718 serve the default @file{/srv/git} over HTTPS might be:
29721 (service nginx-service-type
29722 (nginx-configuration
29725 (nginx-server-configuration
29726 (listen '("443 ssl"))
29727 (server-name "git.my-host.org")
29729 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
29730 (ssl-certificate-key
29731 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
29734 (git-http-nginx-location-configuration
29735 (git-http-configuration (uri-path "/"))))))))))
29738 This example assumes that you are using Let's Encrypt to get your TLS
29739 certificate. @xref{Certificate Services}. The default @code{certbot}
29740 service will redirect all HTTP traffic on @code{git.my-host.org} to
29741 HTTPS@. You will also need to add an @code{fcgiwrap} proxy to your
29742 system services. @xref{Web Services}.
29745 @subsubheading Cgit Service
29747 @cindex Cgit service
29748 @cindex Git, web interface
29749 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
29750 repositories written in C.
29752 The following example will configure the service with default values.
29753 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
29756 (service cgit-service-type)
29759 The @code{file-object} type designates either a file-like object
29760 (@pxref{G-Expressions, file-like objects}) or a string.
29762 @c %start of fragment
29764 Available @code{cgit-configuration} fields are:
29766 @deftypevr {@code{cgit-configuration} parameter} package package
29771 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
29772 NGINX configuration.
29776 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
29777 Specifies a command which will be invoked to format the content of about
29778 pages (both top-level and for each repository).
29780 Defaults to @samp{""}.
29784 @deftypevr {@code{cgit-configuration} parameter} string agefile
29785 Specifies a path, relative to each repository path, which can be used to
29786 specify the date and time of the youngest commit in the repository.
29788 Defaults to @samp{""}.
29792 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
29793 Specifies a command that will be invoked for authenticating repository
29796 Defaults to @samp{""}.
29800 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
29801 Flag which, when set to @samp{age}, enables date ordering in the branch
29802 ref list, and when set @samp{name} enables ordering by branch name.
29804 Defaults to @samp{"name"}.
29808 @deftypevr {@code{cgit-configuration} parameter} string cache-root
29809 Path used to store the cgit cache entries.
29811 Defaults to @samp{"/var/cache/cgit"}.
29815 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
29816 Number which specifies the time-to-live, in minutes, for the cached
29817 version of repository pages accessed with a fixed SHA1.
29819 Defaults to @samp{-1}.
29823 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
29824 Number which specifies the time-to-live, in minutes, for the cached
29825 version of repository pages accessed without a fixed SHA1.
29827 Defaults to @samp{5}.
29831 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
29832 Number which specifies the time-to-live, in minutes, for the cached
29833 version of the repository summary page.
29835 Defaults to @samp{5}.
29839 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
29840 Number which specifies the time-to-live, in minutes, for the cached
29841 version of the repository index page.
29843 Defaults to @samp{5}.
29847 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
29848 Number which specifies the time-to-live, in minutes, for the result of
29849 scanning a path for Git repositories.
29851 Defaults to @samp{15}.
29855 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
29856 Number which specifies the time-to-live, in minutes, for the cached
29857 version of the repository about page.
29859 Defaults to @samp{15}.
29863 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
29864 Number which specifies the time-to-live, in minutes, for the cached
29865 version of snapshots.
29867 Defaults to @samp{5}.
29871 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
29872 The maximum number of entries in the cgit cache. When set to @samp{0},
29873 caching is disabled.
29875 Defaults to @samp{0}.
29879 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
29880 Sort items in the repo list case sensitively.
29882 Defaults to @samp{#t}.
29886 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
29887 List of common prefixes which, when combined with a repository URL,
29888 generates valid clone URLs for the repository.
29890 Defaults to @samp{()}.
29894 @deftypevr {@code{cgit-configuration} parameter} list clone-url
29895 List of @code{clone-url} templates.
29897 Defaults to @samp{()}.
29901 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
29902 Command which will be invoked to format commit messages.
29904 Defaults to @samp{""}.
29908 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
29909 Flag which, when set to @samp{date}, enables strict date ordering in the
29910 commit log, and when set to @samp{topo} enables strict topological
29913 Defaults to @samp{"git log"}.
29917 @deftypevr {@code{cgit-configuration} parameter} file-object css
29918 URL which specifies the css document to include in all cgit pages.
29920 Defaults to @samp{"/share/cgit/cgit.css"}.
29924 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
29925 Specifies a command which will be invoked to format names and email
29926 address of committers, authors, and taggers, as represented in various
29927 places throughout the cgit interface.
29929 Defaults to @samp{""}.
29933 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
29934 Flag which, when set to @samp{#t}, will make cgit generate a HTML
29935 fragment suitable for embedding in other HTML pages.
29937 Defaults to @samp{#f}.
29941 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
29942 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
29943 commit history graph to the left of the commit messages in the
29944 repository log page.
29946 Defaults to @samp{#f}.
29950 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
29951 Flag which, when set to @samp{#t}, allows all filter settings to be
29952 overridden in repository-specific cgitrc files.
29954 Defaults to @samp{#f}.
29958 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
29959 Flag which, when set to @samp{#t}, allows users to follow a file in the
29962 Defaults to @samp{#f}.
29966 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
29967 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
29970 Defaults to @samp{#t}.
29974 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
29975 Flag which, when set to @samp{#t}, will make cgit generate extra links
29976 "summary", "commit", "tree" for each repo in the repository index.
29978 Defaults to @samp{#f}.
29982 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
29983 Flag which, when set to @samp{#t}, will make cgit display the owner of
29984 each repo in the repository index.
29986 Defaults to @samp{#t}.
29990 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
29991 Flag which, when set to @samp{#t}, will make cgit print the number of
29992 modified files for each commit on the repository log page.
29994 Defaults to @samp{#f}.
29998 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
29999 Flag which, when set to @samp{#t}, will make cgit print the number of
30000 added and removed lines for each commit on the repository log page.
30002 Defaults to @samp{#f}.
30006 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
30007 Flag which, when set to @code{#t}, will make cgit display remote
30008 branches in the summary and refs views.
30010 Defaults to @samp{#f}.
30014 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
30015 Flag which, when set to @code{1}, will make cgit use the subject of the
30016 parent commit as link text when generating links to parent commits in
30019 Defaults to @samp{#f}.
30023 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
30024 Flag which, when set to @samp{#t}, will make cgit use the subject of the
30025 parent commit as link text when generating links to parent commits in
30028 Defaults to @samp{#f}.
30032 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
30033 Flag which, when set to @samp{#t}, will make cgit generate linenumber
30034 links for plaintext blobs printed in the tree view.
30036 Defaults to @samp{#t}.
30040 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
30041 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
30042 set any repo specific settings.
30044 Defaults to @samp{#f}.
30048 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
30049 URL used as link to a shortcut icon for cgit.
30051 Defaults to @samp{"/favicon.ico"}.
30055 @deftypevr {@code{cgit-configuration} parameter} string footer
30056 The content of the file specified with this option will be included
30057 verbatim at the bottom of all pages (i.e.@: it replaces the standard
30058 "generated by..."@: message).
30060 Defaults to @samp{""}.
30064 @deftypevr {@code{cgit-configuration} parameter} string head-include
30065 The content of the file specified with this option will be included
30066 verbatim in the HTML HEAD section on all pages.
30068 Defaults to @samp{""}.
30072 @deftypevr {@code{cgit-configuration} parameter} string header
30073 The content of the file specified with this option will be included
30074 verbatim at the top of all pages.
30076 Defaults to @samp{""}.
30080 @deftypevr {@code{cgit-configuration} parameter} file-object include
30081 Name of a configfile to include before the rest of the current config-
30084 Defaults to @samp{""}.
30088 @deftypevr {@code{cgit-configuration} parameter} string index-header
30089 The content of the file specified with this option will be included
30090 verbatim above the repository index.
30092 Defaults to @samp{""}.
30096 @deftypevr {@code{cgit-configuration} parameter} string index-info
30097 The content of the file specified with this option will be included
30098 verbatim below the heading on the repository index page.
30100 Defaults to @samp{""}.
30104 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
30105 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
30106 in the servers timezone.
30108 Defaults to @samp{#f}.
30112 @deftypevr {@code{cgit-configuration} parameter} file-object logo
30113 URL which specifies the source of an image which will be used as a logo
30116 Defaults to @samp{"/share/cgit/cgit.png"}.
30120 @deftypevr {@code{cgit-configuration} parameter} string logo-link
30121 URL loaded when clicking on the cgit logo image.
30123 Defaults to @samp{""}.
30127 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
30128 Command which will be invoked to format the Owner column of the main
30131 Defaults to @samp{""}.
30135 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
30136 Number of items to display in atom feeds view.
30138 Defaults to @samp{10}.
30142 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
30143 Number of entries to list per page in "log" view.
30145 Defaults to @samp{50}.
30149 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
30150 Number of commit message characters to display in "log" view.
30152 Defaults to @samp{80}.
30156 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
30157 Specifies the number of entries to list per page on the repository index
30160 Defaults to @samp{50}.
30164 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
30165 Specifies the maximum number of repo description characters to display
30166 on the repository index page.
30168 Defaults to @samp{80}.
30172 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
30173 Specifies the maximum size of a blob to display HTML for in KBytes.
30175 Defaults to @samp{0}.
30179 @deftypevr {@code{cgit-configuration} parameter} string max-stats
30180 Maximum statistics period. Valid values are @samp{week},@samp{month},
30181 @samp{quarter} and @samp{year}.
30183 Defaults to @samp{""}.
30187 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
30188 Mimetype for the specified filename extension.
30190 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
30191 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
30192 "image/png") (svg "image/svg+xml"))}.
30196 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
30197 Specifies the file to use for automatic mimetype lookup.
30199 Defaults to @samp{""}.
30203 @deftypevr {@code{cgit-configuration} parameter} string module-link
30204 Text which will be used as the formatstring for a hyperlink when a
30205 submodule is printed in a directory listing.
30207 Defaults to @samp{""}.
30211 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
30212 If set to the value @samp{#t} caching will be disabled.
30214 Defaults to @samp{#f}.
30218 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
30219 If set to @samp{#t} showing full author email addresses will be
30222 Defaults to @samp{#f}.
30226 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
30227 Flag which, when set to @samp{#t}, will make cgit omit the standard
30228 header on all pages.
30230 Defaults to @samp{#f}.
30234 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
30235 A list of subdirectories inside of @code{repository-directory}, relative
30236 to it, that should loaded as Git repositories. An empty list means that
30237 all subdirectories will be loaded.
30239 Defaults to @samp{()}.
30243 @deftypevr {@code{cgit-configuration} parameter} file-object readme
30244 Text which will be used as default value for @code{cgit-repo-readme}.
30246 Defaults to @samp{""}.
30250 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
30251 If set to @code{#t} and @code{repository-directory} is enabled, if any
30252 repositories are found with a suffix of @code{.git}, this suffix will be
30253 removed for the URL and name.
30255 Defaults to @samp{#f}.
30259 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
30260 Maximum number of files to consider when detecting renames.
30262 Defaults to @samp{-1}.
30266 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
30267 The way in which repositories in each section are sorted.
30269 Defaults to @samp{""}.
30273 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
30274 Text used as content for the @code{robots} meta-tag.
30276 Defaults to @samp{("noindex" "nofollow")}.
30280 @deftypevr {@code{cgit-configuration} parameter} string root-desc
30281 Text printed below the heading on the repository index page.
30283 Defaults to @samp{"a fast webinterface for the git dscm"}.
30287 @deftypevr {@code{cgit-configuration} parameter} string root-readme
30288 The content of the file specified with this option will be included
30289 verbatim below the ``about'' link on the repository index page.
30291 Defaults to @samp{""}.
30295 @deftypevr {@code{cgit-configuration} parameter} string root-title
30296 Text printed as heading on the repository index page.
30298 Defaults to @samp{""}.
30302 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
30303 If set to @samp{#t} and repository-directory is enabled,
30304 repository-directory will recurse into directories whose name starts
30305 with a period. Otherwise, repository-directory will stay away from such
30306 directories, considered as ``hidden''. Note that this does not apply to
30307 the @file{.git} directory in non-bare repos.
30309 Defaults to @samp{#f}.
30313 @deftypevr {@code{cgit-configuration} parameter} list snapshots
30314 Text which specifies the default set of snapshot formats that cgit
30315 generates links for.
30317 Defaults to @samp{()}.
30321 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
30322 Name of the directory to scan for repositories (represents
30325 Defaults to @samp{"/srv/git"}.
30329 @deftypevr {@code{cgit-configuration} parameter} string section
30330 The name of the current repository section - all repositories defined
30331 after this option will inherit the current section name.
30333 Defaults to @samp{""}.
30337 @deftypevr {@code{cgit-configuration} parameter} string section-sort
30338 Flag which, when set to @samp{1}, will sort the sections on the
30339 repository listing by name.
30341 Defaults to @samp{""}.
30345 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
30346 A number which, if defined prior to repository-directory, specifies how
30347 many path elements from each repo path to use as a default section name.
30349 Defaults to @samp{0}.
30353 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
30354 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
30357 Defaults to @samp{#f}.
30361 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
30362 Specifies a command which will be invoked to format plaintext blobs in
30365 Defaults to @samp{""}.
30369 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
30370 Specifies the number of branches to display in the repository ``summary''
30373 Defaults to @samp{10}.
30377 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
30378 Specifies the number of log entries to display in the repository
30381 Defaults to @samp{10}.
30385 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
30386 Specifies the number of tags to display in the repository ``summary''
30389 Defaults to @samp{10}.
30393 @deftypevr {@code{cgit-configuration} parameter} string strict-export
30394 Filename which, if specified, needs to be present within the repository
30395 for cgit to allow access to that repository.
30397 Defaults to @samp{""}.
30401 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
30402 URL which, if specified, will be used as root for all cgit links.
30404 Defaults to @samp{"/"}.
30408 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
30409 A list of @dfn{cgit-repo} records to use with config.
30411 Defaults to @samp{()}.
30413 Available @code{repository-cgit-configuration} fields are:
30415 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
30416 A mask of snapshot formats for this repo that cgit generates links for,
30417 restricted by the global @code{snapshots} setting.
30419 Defaults to @samp{()}.
30423 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
30424 Override the default @code{source-filter}.
30426 Defaults to @samp{""}.
30430 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
30431 The relative URL used to access the repository.
30433 Defaults to @samp{""}.
30437 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
30438 Override the default @code{about-filter}.
30440 Defaults to @samp{""}.
30444 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
30445 Flag which, when set to @samp{age}, enables date ordering in the branch
30446 ref list, and when set to @samp{name} enables ordering by branch name.
30448 Defaults to @samp{""}.
30452 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
30453 A list of URLs which can be used to clone repo.
30455 Defaults to @samp{()}.
30459 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
30460 Override the default @code{commit-filter}.
30462 Defaults to @samp{""}.
30466 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
30467 Flag which, when set to @samp{date}, enables strict date ordering in the
30468 commit log, and when set to @samp{topo} enables strict topological
30471 Defaults to @samp{""}.
30475 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
30476 The name of the default branch for this repository. If no such branch
30477 exists in the repository, the first branch name (when sorted) is used as
30478 default instead. By default branch pointed to by HEAD, or ``master'' if
30479 there is no suitable HEAD.
30481 Defaults to @samp{""}.
30485 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
30486 The value to show as repository description.
30488 Defaults to @samp{""}.
30492 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
30493 The value to show as repository homepage.
30495 Defaults to @samp{""}.
30499 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
30500 Override the default @code{email-filter}.
30502 Defaults to @samp{""}.
30506 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
30507 A flag which can be used to disable the global setting
30508 @code{enable-commit-graph?}.
30510 Defaults to @samp{disabled}.
30514 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
30515 A flag which can be used to disable the global setting
30516 @code{enable-log-filecount?}.
30518 Defaults to @samp{disabled}.
30522 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
30523 A flag which can be used to disable the global setting
30524 @code{enable-log-linecount?}.
30526 Defaults to @samp{disabled}.
30530 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
30531 Flag which, when set to @code{#t}, will make cgit display remote
30532 branches in the summary and refs views.
30534 Defaults to @samp{disabled}.
30538 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
30539 A flag which can be used to override the global setting
30540 @code{enable-subject-links?}.
30542 Defaults to @samp{disabled}.
30546 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
30547 A flag which can be used to override the global setting
30548 @code{enable-html-serving?}.
30550 Defaults to @samp{disabled}.
30554 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
30555 Flag which, when set to @code{#t}, hides the repository from the
30558 Defaults to @samp{#f}.
30562 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
30563 Flag which, when set to @samp{#t}, ignores the repository.
30565 Defaults to @samp{#f}.
30569 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
30570 URL which specifies the source of an image which will be used as a logo
30571 on this repo’s pages.
30573 Defaults to @samp{""}.
30577 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
30578 URL loaded when clicking on the cgit logo image.
30580 Defaults to @samp{""}.
30584 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
30585 Override the default @code{owner-filter}.
30587 Defaults to @samp{""}.
30591 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
30592 Text which will be used as the formatstring for a hyperlink when a
30593 submodule is printed in a directory listing. The arguments for the
30594 formatstring are the path and SHA1 of the submodule commit.
30596 Defaults to @samp{""}.
30600 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
30601 Text which will be used as the formatstring for a hyperlink when a
30602 submodule with the specified subdirectory path is printed in a directory
30605 Defaults to @samp{()}.
30609 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
30610 Override the default maximum statistics period.
30612 Defaults to @samp{""}.
30616 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
30617 The value to show as repository name.
30619 Defaults to @samp{""}.
30623 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
30624 A value used to identify the owner of the repository.
30626 Defaults to @samp{""}.
30630 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
30631 An absolute path to the repository directory.
30633 Defaults to @samp{""}.
30637 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
30638 A path (relative to repo) which specifies a file to include verbatim as
30639 the ``About'' page for this repo.
30641 Defaults to @samp{""}.
30645 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
30646 The name of the current repository section - all repositories defined
30647 after this option will inherit the current section name.
30649 Defaults to @samp{""}.
30653 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
30654 Extra options will be appended to cgitrc file.
30656 Defaults to @samp{()}.
30662 @deftypevr {@code{cgit-configuration} parameter} list extra-options
30663 Extra options will be appended to cgitrc file.
30665 Defaults to @samp{()}.
30670 @c %end of fragment
30672 However, it could be that you just want to get a @code{cgitrc} up and
30673 running. In that case, you can pass an @code{opaque-cgit-configuration}
30674 as a record to @code{cgit-service-type}. As its name indicates, an
30675 opaque configuration does not have easy reflective capabilities.
30677 Available @code{opaque-cgit-configuration} fields are:
30679 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
30683 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
30684 The contents of the @code{cgitrc}, as a string.
30687 For example, if your @code{cgitrc} is just the empty string, you
30688 could instantiate a cgit service like this:
30691 (service cgit-service-type
30692 (opaque-cgit-configuration
30696 @subsubheading Gitolite Service
30698 @cindex Gitolite service
30699 @cindex Git, hosting
30700 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
30701 repositories on a central server.
30703 Gitolite can handle multiple repositories and users, and supports flexible
30704 configuration of the permissions for the users on the repositories.
30706 The following example will configure Gitolite using the default @code{git}
30707 user, and the provided SSH public key.
30710 (service gitolite-service-type
30711 (gitolite-configuration
30712 (admin-pubkey (plain-file
30714 "ssh-rsa AAAA... guix@@example.com"))))
30717 Gitolite is configured through a special admin repository which you can clone,
30718 for example, if you setup Gitolite on @code{example.com}, you would run the
30719 following command to clone the admin repository.
30722 git clone git@@example.com:gitolite-admin
30725 When the Gitolite service is activated, the provided @code{admin-pubkey} will
30726 be inserted in to the @file{keydir} directory in the gitolite-admin
30727 repository. If this results in a change in the repository, it will be
30728 committed using the message ``gitolite setup by GNU Guix''.
30730 @deftp {Data Type} gitolite-configuration
30731 Data type representing the configuration for @code{gitolite-service-type}.
30734 @item @code{package} (default: @var{gitolite})
30735 Gitolite package to use.
30737 @item @code{user} (default: @var{git})
30738 User to use for Gitolite. This will be user that you use when accessing
30741 @item @code{group} (default: @var{git})
30742 Group to use for Gitolite.
30744 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
30745 Directory in which to store the Gitolite configuration and repositories.
30747 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
30748 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
30749 representing the configuration for Gitolite.
30751 @item @code{admin-pubkey} (default: @var{#f})
30752 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
30753 setup Gitolite. This will be inserted in to the @file{keydir} directory
30754 within the gitolite-admin repository.
30756 To specify the SSH key as a string, use the @code{plain-file} function.
30759 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
30765 @deftp {Data Type} gitolite-rc-file
30766 Data type representing the Gitolite RC file.
30769 @item @code{umask} (default: @code{#o0077})
30770 This controls the permissions Gitolite sets on the repositories and their
30773 A value like @code{#o0027} will give read access to the group used by Gitolite
30774 (by default: @code{git}). This is necessary when using Gitolite with software
30775 like cgit or gitweb.
30777 @item @code{git-config-keys} (default: @code{""})
30778 Gitolite allows you to set git config values using the @samp{config}
30779 keyword. This setting allows control over the config keys to accept.
30781 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
30782 Set the role names allowed to be used by users running the perms command.
30784 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
30785 This setting controls the commands and features to enable within Gitolite.
30791 @node Game Services
30792 @subsection Game Services
30794 @subsubheading The Battle for Wesnoth Service
30796 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
30797 based tactical strategy game, with several single player campaigns, and
30798 multiplayer games (both networked and local).
30800 @defvar {Scheme Variable} wesnothd-service-type
30801 Service type for the wesnothd service. Its value must be a
30802 @code{wesnothd-configuration} object. To run wesnothd in the default
30803 configuration, instantiate it as:
30806 (service wesnothd-service-type)
30810 @deftp {Data Type} wesnothd-configuration
30811 Data type representing the configuration of @command{wesnothd}.
30814 @item @code{package} (default: @code{wesnoth-server})
30815 The wesnoth server package to use.
30817 @item @code{port} (default: @code{15000})
30818 The port to bind the server to.
30823 @node PAM Mount Service
30824 @subsection PAM Mount Service
30827 The @code{(gnu services pam-mount)} module provides a service allowing
30828 users to mount volumes when they log in. It should be able to mount any
30829 volume format supported by the system.
30831 @defvar {Scheme Variable} pam-mount-service-type
30832 Service type for PAM Mount support.
30835 @deftp {Data Type} pam-mount-configuration
30836 Data type representing the configuration of PAM Mount.
30838 It takes the following parameters:
30842 The configuration rules that will be used to generate
30843 @file{/etc/security/pam_mount.conf.xml}.
30845 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
30846 Guile Reference Manual}), and the default ones don't mount anything for
30850 `((debug (@@ (enable "0")))
30851 (mntoptions (@@ (allow ,(string-join
30852 '("nosuid" "nodev" "loop"
30853 "encryption" "fsck" "nonempty"
30854 "allow_root" "allow_other")
30856 (mntoptions (@@ (require "nosuid,nodev")))
30857 (logout (@@ (wait "0")
30861 (mkmountpoint (@@ (enable "1")
30865 Some @code{volume} elements must be added to automatically mount volumes
30866 at login. Here's an example allowing the user @code{alice} to mount her
30867 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
30868 the partition where he stores his data:
30871 (define pam-mount-rules
30872 `((debug (@@ (enable "0")))
30873 (volume (@@ (user "alice")
30876 (mountpoint "/home/alice")))
30877 (volume (@@ (user "bob")
30880 (mountpoint "/home/bob/data")
30881 (options "defaults,autodefrag,compress")))
30882 (mntoptions (@@ (allow ,(string-join
30883 '("nosuid" "nodev" "loop"
30884 "encryption" "fsck" "nonempty"
30885 "allow_root" "allow_other")
30887 (mntoptions (@@ (require "nosuid,nodev")))
30888 (logout (@@ (wait "0")
30892 (mkmountpoint (@@ (enable "1")
30893 (remove "true")))))
30895 (service pam-mount-service-type
30896 (pam-mount-configuration
30897 (rules pam-mount-rules)))
30900 The complete list of possible options can be found in the man page for
30901 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
30906 @node Guix Services
30907 @subsection Guix Services
30909 @subsubheading Guix Build Coordinator
30910 The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
30911 Coordinator} aids in distributing derivation builds among machines
30912 running an @dfn{agent}. The build daemon is still used to build the
30913 derivations, but the Guix Build Coordinator manages allocating builds
30914 and working with the results.
30917 This service is considered experimental. Configuration options may be
30918 changed in a backwards-incompatible manner, and not all features have
30919 been thorougly tested.
30922 The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
30923 more connected @dfn{agent} processes. The coordinator process handles
30924 clients submitting builds, and allocating builds to agents. The agent
30925 processes talk to a build daemon to actually perform the builds, then
30926 send the results back to the coordinator.
30928 There is a script to run the coordinator component of the Guix Build
30929 Coordinator, but the Guix service uses a custom Guile script instead, to
30930 provide better integration with G-expressions used in the configuration.
30932 @defvar {Scheme Variable} guix-build-coordinator-service-type
30933 Service type for the Guix Build Coordinator. Its value must be a
30934 @code{guix-build-coordinator-configuration} object.
30937 @deftp {Data Type} guix-build-coordinator-configuration
30938 Data type representing the configuration of the Guix Build Coordinator.
30941 @item @code{package} (default: @code{guix-build-coordinator})
30942 The Guix Build Coordinator package to use.
30944 @item @code{user} (default: @code{"guix-build-coordinator"})
30945 The system user to run the service as.
30947 @item @code{group} (default: @code{"guix-build-coordinator"})
30948 The system group to run the service as.
30950 @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
30951 The URI to use for the database.
30953 @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
30954 The URI describing how to listen to requests from agent processes.
30956 @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
30957 The URI describing how to listen to requests from clients. The client
30958 API allows submitting builds and currently isn't authenticated, so take
30959 care when configuring this value.
30961 @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
30962 A G-expression for the allocation strategy to be used. This is a
30963 procedure that takes the datastore as an argument and populates the
30964 allocation plan in the database.
30966 @item @code{hooks} (default: @var{'()})
30967 An association list of hooks. These provide a way to execute arbitrary
30968 code upon certain events, like a build result being processed.
30970 @item @code{guile} (default: @code{guile-3.0-latest})
30971 The Guile package with which to run the Guix Build Coordinator.
30976 @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
30977 Service type for a Guix Build Coordinator agent. Its value must be a
30978 @code{guix-build-coordinator-agent-configuration} object.
30981 @deftp {Data Type} guix-build-coordinator-agent-configuration
30982 Data type representing the configuration a Guix Build Coordinator agent.
30985 @item @code{package} (default: @code{guix-build-coordinator})
30986 The Guix Build Coordinator package to use.
30988 @item @code{user} (default: @code{"guix-build-coordinator-agent"})
30989 The system user to run the service as.
30991 @item @code{coordinator} (default: @code{"http://localhost:8745"})
30992 The URI to use when connecting to the coordinator.
30994 @item @code{authentication}
30995 Record describing how this agent should authenticate with the
30996 coordinator. Possible record types are described below.
30998 @item @code{systems} (default: @code{#f})
30999 The systems for which this agent should fetch builds. The agent process
31000 will use the current system it's running on as the default.
31002 @item @code{max-parallel-builds} (default: @code{1})
31003 The number of builds to perform in parallel.
31005 @item @code{derivation-substitute-urls} (default: @code{#f})
31006 URLs from which to attempt to fetch substitutes for derivations, if the
31007 derivations aren't already available.
31009 @item @code{non-derivation-substitute-urls} (default: @code{#f})
31010 URLs from which to attempt to fetch substitutes for build inputs, if the
31011 input store items aren't already available.
31016 @deftp {Data Type} guix-build-coordinator-agent-password-auth
31017 Data type representing an agent authenticating with a coordinator via a
31022 The UUID of the agent. This should be generated by the coordinator
31023 process, stored in the coordinator database, and used by the intended
31026 @item @code{password}
31027 The password to use when connecting to the coordinator.
31032 @deftp {Data Type} guix-build-coordinator-agent-password-file-auth
31033 Data type representing an agent authenticating with a coordinator via a
31034 UUID and password read from a file.
31038 The UUID of the agent. This should be generated by the coordinator
31039 process, stored in the coordinator database, and used by the intended
31042 @item @code{password-file}
31043 A file containing the password to use when connecting to the
31049 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth
31050 Data type representing an agent authenticating with a coordinator via a
31051 dyanmic auth token and agent name.
31054 @item @code{agent-name}
31055 Name of an agent, this is used to match up to an existing entry in the
31056 database if there is one. When no existing entry is found, a new entry
31057 is automatically added.
31060 Dynamic auth token, this is created and stored in the coordinator
31061 database, and is used by the agent to authenticate.
31066 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth-with-file
31067 Data type representing an agent authenticating with a coordinator via a
31068 dyanmic auth token read from a file and agent name.
31071 @item @code{agent-name}
31072 Name of an agent, this is used to match up to an existing entry in the
31073 database if there is one. When no existing entry is found, a new entry
31074 is automatically added.
31076 @item @code{token-file}
31077 File containing the dynamic auth token, this is created and stored in
31078 the coordinator database, and is used by the agent to authenticate.
31083 The Guix Build Coordinator package contains a script to query an
31084 instance of the Guix Data Service for derivations to build, and then
31085 submit builds for those derivations to the coordinator. The service
31086 type below assists in running this script. This is an additional tool
31087 that may be useful when building derivations contained within an
31088 instance of the Guix Data Service.
31090 @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
31091 Service type for the
31092 guix-build-coordinator-queue-builds-from-guix-data-service script. Its
31093 value must be a @code{guix-build-coordinator-queue-builds-configuration}
31097 @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
31098 Data type representing the options to the queue builds from guix data
31102 @item @code{package} (default: @code{guix-build-coordinator})
31103 The Guix Build Coordinator package to use.
31105 @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
31106 The system user to run the service as.
31108 @item @code{coordinator} (default: @code{"http://localhost:8745"})
31109 The URI to use when connecting to the coordinator.
31111 @item @code{systems} (default: @code{#f})
31112 The systems for which to fetch derivations to build.
31114 @item @code{systems-and-targets} (default: @code{#f})
31115 An association list of system and target pairs for which to fetch
31116 derivations to build.
31118 @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
31119 The Guix Data Service instance from which to query to find out about
31120 derivations to build.
31122 @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
31123 A file to record which commits have been processed, to avoid needlessly
31124 processing them again if the service is restarted.
31129 @subsubheading Guix Data Service
31130 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
31131 and provides data about GNU Guix. This includes information about
31132 packages, derivations and lint warnings.
31134 The data is stored in a PostgreSQL database, and available through a web
31137 @defvar {Scheme Variable} guix-data-service-type
31138 Service type for the Guix Data Service. Its value must be a
31139 @code{guix-data-service-configuration} object. The service optionally
31140 extends the getmail service, as the guix-commits mailing list is used to
31141 find out about changes in the Guix git repository.
31144 @deftp {Data Type} guix-data-service-configuration
31145 Data type representing the configuration of the Guix Data Service.
31148 @item @code{package} (default: @code{guix-data-service})
31149 The Guix Data Service package to use.
31151 @item @code{user} (default: @code{"guix-data-service"})
31152 The system user to run the service as.
31154 @item @code{group} (default: @code{"guix-data-service"})
31155 The system group to run the service as.
31157 @item @code{port} (default: @code{8765})
31158 The port to bind the web service to.
31160 @item @code{host} (default: @code{"127.0.0.1"})
31161 The host to bind the web service to.
31163 @item @code{getmail-idle-mailboxes} (default: @code{#f})
31164 If set, this is the list of mailboxes that the getmail service will be
31165 configured to listen to.
31167 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
31168 If set, this is the @code{getmail-retriever-configuration} object with
31169 which to configure getmail to fetch mail from the guix-commits mailing
31172 @item @code{extra-options} (default: @var{'()})
31173 Extra command line options for @code{guix-data-service}.
31175 @item @code{extra-process-jobs-options} (default: @var{'()})
31176 Extra command line options for @code{guix-data-service-process-jobs}.
31181 @node Linux Services
31182 @subsection Linux Services
31185 @cindex out of memory killer
31187 @cindex early out of memory daemon
31188 @subsubheading Early OOM Service
31190 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
31191 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
31192 space and provides a more responsive and configurable alternative to the
31193 in-kernel OOM killer. It is useful to prevent the system from becoming
31194 unresponsive when it runs out of memory.
31196 @deffn {Scheme Variable} earlyoom-service-type
31197 The service type for running @command{earlyoom}, the Early OOM daemon.
31198 Its value must be a @code{earlyoom-configuration} object, described
31199 below. The service can be instantiated in its default configuration
31203 (service earlyoom-service-type)
31207 @deftp {Data Type} earlyoom-configuration
31208 This is the configuration record for the @code{earlyoom-service-type}.
31211 @item @code{earlyoom} (default: @var{earlyoom})
31212 The Earlyoom package to use.
31214 @item @code{minimum-available-memory} (default: @code{10})
31215 The threshold for the minimum @emph{available} memory, in percentages.
31217 @item @code{minimum-free-swap} (default: @code{10})
31218 The threshold for the minimum free swap memory, in percentages.
31220 @item @code{prefer-regexp} (default: @code{#f})
31221 A regular expression (as a string) to match the names of the processes
31222 that should be preferably killed.
31224 @item @code{avoid-regexp} (default: @code{#f})
31225 A regular expression (as a string) to match the names of the processes
31226 that should @emph{not} be killed.
31228 @item @code{memory-report-interval} (default: @code{0})
31229 The interval in seconds at which a memory report is printed. It is
31230 disabled by default.
31232 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
31233 A boolean indicating whether the positive adjustments set in
31234 @file{/proc/*/oom_score_adj} should be ignored.
31236 @item @code{show-debug-messages?} (default: @code{#f})
31237 A boolean indicating whether debug messages should be printed. The logs
31238 are saved at @file{/var/log/earlyoom.log}.
31240 @item @code{send-notification-command} (default: @code{#f})
31241 This can be used to provide a custom command used for sending
31247 @cindex kernel module loader
31248 @subsubheading Kernel Module Loader Service
31250 The kernel module loader service allows one to load loadable kernel
31251 modules at boot. This is especially useful for modules that don't
31252 autoload and need to be manually loaded, as it's the case with
31255 @deffn {Scheme Variable} kernel-module-loader-service-type
31256 The service type for loading loadable kernel modules at boot with
31257 @command{modprobe}. Its value must be a list of strings representing
31258 module names. For example loading the drivers provided by
31259 @code{ddcci-driver-linux}, in debugging mode by passing some module
31260 parameters, can be done as follow:
31263 (use-modules (gnu) (gnu services))
31264 (use-package-modules linux)
31265 (use-service-modules linux)
31267 (define ddcci-config
31268 (plain-file "ddcci.conf"
31269 "options ddcci dyndbg delay=120"))
31273 (services (cons* (service kernel-module-loader-service-type
31274 '("ddcci" "ddcci_backlight"))
31275 (simple-service 'ddcci-config etc-service-type
31276 (list `("modprobe.d/ddcci.conf"
31279 (kernel-loadable-modules (list ddcci-driver-linux)))
31284 @cindex compressed swap
31285 @cindex Compressed RAM-based block devices
31286 @subsubheading Zram Device Service
31288 The Zram device service provides a compressed swap device in system
31289 memory. The Linux Kernel documentation has more information about
31290 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
31293 @deffn {Scheme Variable} zram-device-service-type
31294 This service creates the zram block device, formats it as swap and
31295 enables it as a swap device. The service's value is a
31296 @code{zram-device-configuration} record.
31298 @deftp {Data Type} zram-device-configuration
31299 This is the data type representing the configuration for the zram-device
31303 @item @code{size} (default @code{"1G"})
31304 This is the amount of space you wish to provide for the zram device. It
31305 accepts a string and can be a number of bytes or use a suffix, eg.:
31306 @code{"512M"} or @code{1024000}.
31307 @item @code{compression-algorithm} (default @code{'lzo})
31308 This is the compression algorithm you wish to use. It is difficult to
31309 list all the possible compression options, but common ones supported by
31310 Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
31311 @item @code{memory-limit} (default @code{0})
31312 This is the maximum amount of memory which the zram device can use.
31313 Setting it to '0' disables the limit. While it is generally expected
31314 that compression will be 2:1, it is possible that uncompressable data
31315 can be written to swap and this is a method to limit how much memory can
31316 be used. It accepts a string and can be a number of bytes or use a
31317 suffix, eg.: @code{"2G"}.
31318 @item @code{priority} (default @code{-1})
31319 This is the priority of the swap device created from the zram device.
31320 @code{swapon} accepts values between -1 and 32767, with higher values
31321 indicating higher priority. Higher priority swap will generally be used
31328 @node Hurd Services
31329 @subsection Hurd Services
31331 @defvr {Scheme Variable} hurd-console-service-type
31332 This service starts the fancy @code{VGA} console client on the Hurd.
31334 The service's value is a @code{hurd-console-configuration} record.
31337 @deftp {Data Type} hurd-console-configuration
31338 This is the data type representing the configuration for the
31339 hurd-console-service.
31342 @item @code{hurd} (default: @var{hurd})
31343 The Hurd package to use.
31347 @defvr {Scheme Variable} hurd-getty-service-type
31348 This service starts a tty using the Hurd @code{getty} program.
31350 The service's value is a @code{hurd-getty-configuration} record.
31353 @deftp {Data Type} hurd-getty-configuration
31354 This is the data type representing the configuration for the
31355 hurd-getty-service.
31358 @item @code{hurd} (default: @var{hurd})
31359 The Hurd package to use.
31362 The name of the console this Getty runs on---e.g., @code{"tty1"}.
31364 @item @code{baud-rate} (default: @code{38400})
31365 An integer specifying the baud rate of the tty.
31370 @node Miscellaneous Services
31371 @subsection Miscellaneous Services
31373 @cindex fingerprint
31374 @subsubheading Fingerprint Service
31376 The @code{(gnu services authentication)} module provides a DBus service to
31377 read and identify fingerprints via a fingerprint sensor.
31379 @defvr {Scheme Variable} fprintd-service-type
31380 The service type for @command{fprintd}, which provides the fingerprint
31381 reading capability.
31384 (service fprintd-service-type)
31389 @subsubheading System Control Service
31391 The @code{(gnu services sysctl)} provides a service to configure kernel
31392 parameters at boot.
31394 @defvr {Scheme Variable} sysctl-service-type
31395 The service type for @command{sysctl}, which modifies kernel parameters
31396 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
31400 (service sysctl-service-type
31401 (sysctl-configuration
31402 (settings '(("net.ipv4.ip_forward" . "1")))))
31405 Since @code{sysctl-service-type} is used in the default lists of
31406 services, @code{%base-services} and @code{%desktop-services}, you can
31407 use @code{modify-services} to change its configuration and add the
31408 kernel parameters that you want (@pxref{Service Reference,
31409 @code{modify-services}}).
31412 (modify-services %base-services
31413 (sysctl-service-type config =>
31414 (sysctl-configuration
31415 (settings (append '(("net.ipv4.ip_forward" . "1"))
31416 %default-sysctl-settings)))))
31421 @deftp {Data Type} sysctl-configuration
31422 The data type representing the configuration of @command{sysctl}.
31425 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
31426 The @command{sysctl} executable to use.
31428 @item @code{settings} (default: @code{%default-sysctl-settings})
31429 An association list specifies kernel parameters and their values.
31433 @defvr {Scheme Variable} %default-sysctl-settings
31434 An association list specifying the default @command{sysctl} parameters
31439 @subsubheading PC/SC Smart Card Daemon Service
31441 The @code{(gnu services security-token)} module provides the following service
31442 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
31443 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
31444 manager that coordinates communications with smart card readers, smart cards
31445 and cryptographic tokens that are connected to the system.
31447 @defvr {Scheme Variable} pcscd-service-type
31448 Service type for the @command{pcscd} service. Its value must be a
31449 @code{pcscd-configuration} object. To run pcscd in the default
31450 configuration, instantiate it as:
31453 (service pcscd-service-type)
31457 @deftp {Data Type} pcscd-configuration
31458 The data type representing the configuration of @command{pcscd}.
31461 @item @code{pcsc-lite} (default: @code{pcsc-lite})
31462 The pcsc-lite package that provides pcscd.
31463 @item @code{usb-drivers} (default: @code{(list ccid)})
31464 List of packages that provide USB drivers to pcscd. Drivers are expected to be
31465 under @file{pcsc/drivers} in the store directory of the package.
31470 @subsubheading Lirc Service
31472 The @code{(gnu services lirc)} module provides the following service.
31474 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
31475 [#:device #f] [#:driver #f] [#:config-file #f] @
31476 [#:extra-options '()]
31477 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
31478 decodes infrared signals from remote controls.
31480 Optionally, @var{device}, @var{driver} and @var{config-file}
31481 (configuration file name) may be specified. See @command{lircd} manual
31484 Finally, @var{extra-options} is a list of additional command-line options
31485 passed to @command{lircd}.
31489 @subsubheading Spice Service
31491 The @code{(gnu services spice)} module provides the following service.
31493 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
31494 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
31495 that enables sharing the clipboard with a vm and setting the guest display
31496 resolution when the graphical console window resizes.
31499 @cindex inputattach
31500 @subsubheading inputattach Service
31502 @cindex tablet input, for Xorg
31503 @cindex touchscreen input, for Xorg
31504 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
31505 use input devices such as Wacom tablets, touchscreens, or joysticks with the
31506 Xorg display server.
31508 @deffn {Scheme Variable} inputattach-service-type
31509 Type of a service that runs @command{inputattach} on a device and
31510 dispatches events from it.
31513 @deftp {Data Type} inputattach-configuration
31515 @item @code{device-type} (default: @code{"wacom"})
31516 The type of device to connect to. Run @command{inputattach --help}, from the
31517 @code{inputattach} package, to see the list of supported device types.
31519 @item @code{device} (default: @code{"/dev/ttyS0"})
31520 The device file to connect to the device.
31522 @item @code{baud-rate} (default: @code{#f})
31523 Baud rate to use for the serial connection.
31524 Should be a number or @code{#f}.
31526 @item @code{log-file} (default: @code{#f})
31527 If true, this must be the name of a file to log messages to.
31531 @subsubheading Dictionary Service
31533 The @code{(gnu services dict)} module provides the following service:
31535 @defvr {Scheme Variable} dicod-service-type
31536 This is the type of the service that runs the @command{dicod} daemon, an
31537 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
31540 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
31541 Return a service that runs the @command{dicod} daemon, an implementation
31542 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
31544 The optional @var{config} argument specifies the configuration for
31545 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
31546 default it serves the GNU Collaborative International Dictionary of English.
31548 You can add @command{open localhost} to your @file{~/.dico} file to make
31549 @code{localhost} the default server for @command{dico} client
31550 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
31553 @deftp {Data Type} dicod-configuration
31554 Data type representing the configuration of dicod.
31557 @item @code{dico} (default: @var{dico})
31558 Package object of the GNU Dico dictionary server.
31560 @item @code{interfaces} (default: @var{'("localhost")})
31561 This is the list of IP addresses and ports and possibly socket file
31562 names to listen to (@pxref{Server Settings, @code{listen} directive,,
31563 dico, GNU Dico Manual}).
31565 @item @code{handlers} (default: @var{'()})
31566 List of @code{<dicod-handler>} objects denoting handlers (module instances).
31568 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
31569 List of @code{<dicod-database>} objects denoting dictionaries to be served.
31573 @deftp {Data Type} dicod-handler
31574 Data type representing a dictionary handler (module instance).
31578 Name of the handler (module instance).
31580 @item @code{module} (default: @var{#f})
31581 Name of the dicod module of the handler (instance). If it is @code{#f},
31582 the module has the same name as the handler.
31583 (@pxref{Modules,,, dico, GNU Dico Manual}).
31585 @item @code{options}
31586 List of strings or gexps representing the arguments for the module handler
31590 @deftp {Data Type} dicod-database
31591 Data type representing a dictionary database.
31595 Name of the database, will be used in DICT commands.
31597 @item @code{handler}
31598 Name of the dicod handler (module instance) used by this database
31599 (@pxref{Handlers,,, dico, GNU Dico Manual}).
31601 @item @code{complex?} (default: @var{#f})
31602 Whether the database configuration complex. The complex configuration
31603 will need a corresponding @code{<dicod-handler>} object, otherwise not.
31605 @item @code{options}
31606 List of strings or gexps representing the arguments for the database
31607 (@pxref{Databases,,, dico, GNU Dico Manual}).
31611 @defvr {Scheme Variable} %dicod-database:gcide
31612 A @code{<dicod-database>} object serving the GNU Collaborative International
31613 Dictionary of English using the @code{gcide} package.
31616 The following is an example @code{dicod-service} configuration.
31619 (dicod-service #:config
31620 (dicod-configuration
31621 (handlers (list (dicod-handler
31625 (list #~(string-append "dbdir=" #$wordnet))))))
31626 (databases (list (dicod-database
31629 (handler "wordnet")
31630 (options '("database=wn")))
31631 %dicod-database:gcide))))
31635 @subsubheading Docker Service
31637 The @code{(gnu services docker)} module provides the following services.
31639 @defvr {Scheme Variable} docker-service-type
31641 This is the type of the service that runs @url{https://www.docker.com,Docker},
31642 a daemon that can execute application bundles (sometimes referred to as
31643 ``containers'') in isolated environments.
31647 @deftp {Data Type} docker-configuration
31648 This is the data type representing the configuration of Docker and Containerd.
31652 @item @code{package} (default: @code{docker})
31653 The Docker daemon package to use.
31655 @item @code{package} (default: @code{docker-cli})
31656 The Docker client package to use.
31658 @item @code{containerd} (default: @var{containerd})
31659 The Containerd package to use.
31661 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
31662 The Docker user-land networking proxy package to use.
31664 @item @code{enable-proxy?} (default @code{#t})
31665 Enable or disable the use of the Docker user-land networking proxy.
31667 @item @code{debug?} (default @code{#f})
31668 Enable or disable debug output.
31670 @item @code{enable-iptables?} (default @code{#t})
31671 Enable or disable the addition of iptables rules.
31676 @cindex Singularity, container service
31677 @defvr {Scheme Variable} singularity-service-type
31678 This is the type of the service that allows you to run
31679 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
31680 create and run application bundles (aka. ``containers''). The value for this
31681 service is the Singularity package to use.
31683 The service does not install a daemon; instead, it installs helper programs as
31684 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
31685 @command{singularity run} and similar commands.
31689 @subsubheading Auditd Service
31691 The @code{(gnu services auditd)} module provides the following service.
31693 @defvr {Scheme Variable} auditd-service-type
31695 This is the type of the service that runs
31696 @url{https://people.redhat.com/sgrubb/audit/,auditd},
31697 a daemon that tracks security-relevant information on your system.
31699 Examples of things that can be tracked:
31709 Failed login attempts
31716 @command{auditctl} from the @code{audit} package can be used in order
31717 to add or remove events to be tracked (until the next reboot).
31718 In order to permanently track events, put the command line arguments
31719 of auditctl into a file called @code{audit.rules} in the configuration
31720 directory (see below).
31721 @command{aureport} from the @code{audit} package can be used in order
31722 to view a report of all recorded events.
31723 The audit daemon by default logs into the file
31724 @file{/var/log/audit.log}.
31728 @deftp {Data Type} auditd-configuration
31729 This is the data type representing the configuration of auditd.
31733 @item @code{audit} (default: @code{audit})
31734 The audit package to use.
31736 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
31737 The directory containing the configuration file for the audit package, which
31738 must be named @code{auditd.conf}, and optionally some audit rules to
31739 instantiate on startup.
31745 @subsubheading R-Shiny service
31747 The @code{(gnu services science)} module provides the following service.
31749 @defvr {Scheme Variable} rshiny-service-type
31751 This is a type of service which is used to run a webapp created with
31752 @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
31753 variable and runs the provided script to call @code{runApp}.
31755 @deftp {Data Type} rshiny-configuration
31756 This is the data type representing the configuration of rshiny.
31760 @item @code{package} (default: @code{r-shiny})
31761 The package to use.
31763 @item @code{binary} (defaunlt @code{"rshiny"})
31764 The name of the binary or shell script located at @code{package/bin/} to
31765 run when the service is run.
31767 The common way to create this file is as follows:
31771 (let* ((out (assoc-ref %outputs "out"))
31772 (targetdir (string-append out "/share/" ,name))
31773 (app (string-append out "/bin/" ,name))
31774 (Rbin (string-append (assoc-ref %build-inputs "r-min")
31777 (mkdir-p (string-append out "/bin"))
31778 (call-with-output-file app
31784 runApp(launch.browser=0, port=4202)~%\n"
31793 @subsubheading Nix service
31795 The @code{(gnu services nix)} module provides the following service.
31797 @defvr {Scheme Variable} nix-service-type
31799 This is the type of the service that runs build daemon of the
31800 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
31804 (use-modules (gnu))
31805 (use-service-modules nix)
31806 (use-package-modules package-management)
31810 (packages (append (list nix)
31813 (services (append (list (service nix-service-type))
31817 After @command{guix system reconfigure} configure Nix for your user:
31820 @item Add a Nix channel and update it. See
31821 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
31823 @item Create a symlink to your profile and activate Nix profile:
31827 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
31828 $ source /run/current-system/profile/etc/profile.d/nix.sh
31833 @deftp {Data Type} nix-configuration
31834 This data type represents the configuration of the Nix daemon.
31837 @item @code{nix} (default: @code{nix})
31838 The Nix package to use.
31840 @item @code{sandbox} (default: @code{#t})
31841 Specifies whether builds are sandboxed by default.
31843 @item @code{build-sandbox-items} (default: @code{'()})
31844 This is a list of strings or objects appended to the
31845 @code{build-sandbox-items} field of the configuration file.
31847 @item @code{extra-config} (default: @code{'()})
31848 This is a list of strings or objects appended to the configuration file.
31849 It is used to pass extra text to be added verbatim to the configuration
31852 @item @code{extra-options} (default: @code{'()})
31853 Extra command line options for @code{nix-service-type}.
31857 @node Setuid Programs
31858 @section Setuid Programs
31860 @cindex setuid programs
31861 Some programs need to run with ``root'' privileges, even when they are
31862 launched by unprivileged users. A notorious example is the
31863 @command{passwd} program, which users can run to change their
31864 password, and which needs to access the @file{/etc/passwd} and
31865 @file{/etc/shadow} files---something normally restricted to root, for
31866 obvious security reasons. To address that, these executables are
31867 @dfn{setuid-root}, meaning that they always run with root privileges
31868 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
31869 for more info about the setuid mechanism).
31871 The store itself @emph{cannot} contain setuid programs: that would be a
31872 security issue since any user on the system can write derivations that
31873 populate the store (@pxref{The Store}). Thus, a different mechanism is
31874 used: instead of changing the setuid bit directly on files that are in
31875 the store, we let the system administrator @emph{declare} which programs
31876 should be setuid root.
31878 The @code{setuid-programs} field of an @code{operating-system}
31879 declaration contains a list of G-expressions denoting the names of
31880 programs to be setuid-root (@pxref{Using the Configuration System}).
31881 For instance, the @command{passwd} program, which is part of the Shadow
31882 package, can be designated by this G-expression (@pxref{G-Expressions}):
31885 #~(string-append #$shadow "/bin/passwd")
31888 A default set of setuid programs is defined by the
31889 @code{%setuid-programs} variable of the @code{(gnu system)} module.
31891 @defvr {Scheme Variable} %setuid-programs
31892 A list of G-expressions denoting common programs that are setuid-root.
31894 The list includes commands such as @command{passwd}, @command{ping},
31895 @command{su}, and @command{sudo}.
31898 Under the hood, the actual setuid programs are created in the
31899 @file{/run/setuid-programs} directory at system activation time. The
31900 files in this directory refer to the ``real'' binaries, which are in the
31903 @node X.509 Certificates
31904 @section X.509 Certificates
31906 @cindex HTTPS, certificates
31907 @cindex X.509 certificates
31909 Web servers available over HTTPS (that is, HTTP over the transport-layer
31910 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
31911 that the client can then use to @emph{authenticate} the server. To do
31912 that, clients verify that the server's certificate is signed by a
31913 so-called @dfn{certificate authority} (CA). But to verify the CA's
31914 signature, clients must have first acquired the CA's certificate.
31916 Web browsers such as GNU@tie{}IceCat include their own set of CA
31917 certificates, such that they are able to verify CA signatures
31920 However, most other programs that can talk HTTPS---@command{wget},
31921 @command{git}, @command{w3m}, etc.---need to be told where CA
31922 certificates can be found.
31924 @cindex @code{nss-certs}
31925 In Guix, this is done by adding a package that provides certificates
31926 to the @code{packages} field of the @code{operating-system} declaration
31927 (@pxref{operating-system Reference}). Guix includes one such package,
31928 @code{nss-certs}, which is a set of CA certificates provided as part of
31929 Mozilla's Network Security Services.
31931 Note that it is @emph{not} part of @code{%base-packages}, so you need to
31932 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
31933 most applications and libraries look for certificates by default, points
31934 to the certificates installed globally.
31936 Unprivileged users, including users of Guix on a foreign distro,
31937 can also install their own certificate package in
31938 their profile. A number of environment variables need to be defined so
31939 that applications and libraries know where to find them. Namely, the
31940 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
31941 variables. Some applications add their own environment variables; for
31942 instance, the Git version control system honors the certificate bundle
31943 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
31944 would typically run something like:
31947 guix install nss-certs
31948 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
31949 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
31950 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
31953 As another example, R requires the @env{CURL_CA_BUNDLE} environment
31954 variable to point to a certificate bundle, so you would have to run
31955 something like this:
31958 guix install nss-certs
31959 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
31962 For other applications you may want to look up the required environment
31963 variable in the relevant documentation.
31966 @node Name Service Switch
31967 @section Name Service Switch
31969 @cindex name service switch
31971 The @code{(gnu system nss)} module provides bindings to the
31972 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
31973 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
31974 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
31975 extended with new ``name'' lookup methods for system databases, which
31976 includes host names, service names, user accounts, and more (@pxref{Name
31977 Service Switch, System Databases and Name Service Switch,, libc, The GNU
31978 C Library Reference Manual}).
31980 The NSS configuration specifies, for each system database, which lookup
31981 method is to be used, and how the various methods are chained
31982 together---for instance, under which circumstances NSS should try the
31983 next method in the list. The NSS configuration is given in the
31984 @code{name-service-switch} field of @code{operating-system} declarations
31985 (@pxref{operating-system Reference, @code{name-service-switch}}).
31988 @cindex .local, host name lookup
31989 As an example, the declaration below configures the NSS to use the
31990 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
31991 back-end}, which supports host name lookups over multicast DNS (mDNS)
31992 for host names ending in @code{.local}:
31995 (name-service-switch
31996 (hosts (list %files ;first, check /etc/hosts
31998 ;; If the above did not succeed, try
31999 ;; with 'mdns_minimal'.
32001 (name "mdns_minimal")
32003 ;; 'mdns_minimal' is authoritative for
32004 ;; '.local'. When it returns "not found",
32005 ;; no need to try the next methods.
32006 (reaction (lookup-specification
32007 (not-found => return))))
32009 ;; Then fall back to DNS.
32013 ;; Finally, try with the "full" 'mdns'.
32018 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
32019 contains this configuration, so you will not have to type it if all you
32020 want is to have @code{.local} host lookup working.
32022 Note that, in this case, in addition to setting the
32023 @code{name-service-switch} of the @code{operating-system} declaration,
32024 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
32025 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
32026 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
32027 to the name service cache daemon (@pxref{Base Services,
32028 @code{nscd-service}}).
32030 For convenience, the following variables provide typical NSS
32033 @defvr {Scheme Variable} %default-nss
32034 This is the default name service switch configuration, a
32035 @code{name-service-switch} object.
32038 @defvr {Scheme Variable} %mdns-host-lookup-nss
32039 This is the name service switch configuration with support for host name
32040 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
32043 The reference for name service switch configuration is given below. It
32044 is a direct mapping of the configuration file format of the C library , so
32045 please refer to the C library manual for more information (@pxref{NSS
32046 Configuration File,,, libc, The GNU C Library Reference Manual}).
32047 Compared to the configuration file format of libc NSS, it has the advantage
32048 not only of adding this warm parenthetic feel that we like, but also
32049 static checks: you will know about syntax errors and typos as soon as you
32050 run @command{guix system}.
32052 @deftp {Data Type} name-service-switch
32054 This is the data type representation the configuration of libc's name
32055 service switch (NSS). Each field below represents one of the supported
32072 The system databases handled by the NSS@. Each of these fields must be a
32073 list of @code{<name-service>} objects (see below).
32077 @deftp {Data Type} name-service
32079 This is the data type representing an actual name service and the
32080 associated lookup action.
32084 A string denoting the name service (@pxref{Services in the NSS
32085 configuration,,, libc, The GNU C Library Reference Manual}).
32087 Note that name services listed here must be visible to nscd. This is
32088 achieved by passing the @code{#:name-services} argument to
32089 @code{nscd-service} the list of packages providing the needed name
32090 services (@pxref{Base Services, @code{nscd-service}}).
32093 An action specified using the @code{lookup-specification} macro
32094 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
32095 Reference Manual}). For example:
32098 (lookup-specification (unavailable => continue)
32099 (success => return))
32104 @node Initial RAM Disk
32105 @section Initial RAM Disk
32108 @cindex initial RAM disk
32109 For bootstrapping purposes, the Linux-Libre kernel is passed an
32110 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
32111 root file system as well as an initialization script. The latter is
32112 responsible for mounting the real root file system, and for loading any
32113 kernel modules that may be needed to achieve that.
32115 The @code{initrd-modules} field of an @code{operating-system}
32116 declaration allows you to specify Linux-libre kernel modules that must
32117 be available in the initrd. In particular, this is where you would list
32118 modules needed to actually drive the hard disk where your root partition
32119 is---although the default value of @code{initrd-modules} should cover
32120 most use cases. For example, assuming you need the @code{megaraid_sas}
32121 module in addition to the default modules to be able to access your root
32122 file system, you would write:
32127 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
32130 @defvr {Scheme Variable} %base-initrd-modules
32131 This is the list of kernel modules included in the initrd by default.
32134 Furthermore, if you need lower-level customization, the @code{initrd}
32135 field of an @code{operating-system} declaration allows
32136 you to specify which initrd you would like to use. The @code{(gnu
32137 system linux-initrd)} module provides three ways to build an initrd: the
32138 high-level @code{base-initrd} procedure and the low-level
32139 @code{raw-initrd} and @code{expression->initrd} procedures.
32141 The @code{base-initrd} procedure is intended to cover most common uses.
32142 For example, if you want to add a bunch of kernel modules to be loaded
32143 at boot time, you can define the @code{initrd} field of the operating
32144 system declaration like this:
32147 (initrd (lambda (file-systems . rest)
32148 ;; Create a standard initrd but set up networking
32149 ;; with the parameters QEMU expects by default.
32150 (apply base-initrd file-systems
32151 #:qemu-networking? #t
32155 The @code{base-initrd} procedure also handles common use cases that
32156 involves using the system as a QEMU guest, or as a ``live'' system with
32157 volatile root file system.
32159 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
32160 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
32161 such as trying to guess which kernel modules and packages should be included
32162 to the initrd. An example use of @code{raw-initrd} is when a user has
32163 a custom Linux kernel configuration and default kernel modules included by
32164 @code{base-initrd} are not available.
32166 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
32167 honors several options passed on the Linux kernel command line
32168 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
32169 @code{-append} option of QEMU), notably:
32172 @item --load=@var{boot}
32173 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
32174 program, once it has mounted the root file system.
32176 Guix uses this option to yield control to a boot program that runs the
32177 service activation programs and then spawns the GNU@tie{}Shepherd, the
32178 initialization system.
32180 @item --root=@var{root}
32181 Mount @var{root} as the root file system. @var{root} can be a device
32182 name like @code{/dev/sda1}, a file system label, or a file system UUID.
32183 When unspecified, the device name from the root file system of the
32184 operating system declaration is used.
32186 @item --system=@var{system}
32187 Have @file{/run/booted-system} and @file{/run/current-system} point to
32190 @item modprobe.blacklist=@var{modules}@dots{}
32191 @cindex module, black-listing
32192 @cindex black list, of kernel modules
32193 Instruct the initial RAM disk as well as the @command{modprobe} command
32194 (from the kmod package) to refuse to load @var{modules}. @var{modules}
32195 must be a comma-separated list of module names---e.g.,
32196 @code{usbkbd,9pnet}.
32199 Start a read-eval-print loop (REPL) from the initial RAM disk before it
32200 tries to load kernel modules and to mount the root file system. Our
32201 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
32202 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
32203 Manual}, for more information on Guile's REPL.
32207 Now that you know all the features that initial RAM disks produced by
32208 @code{base-initrd} and @code{raw-initrd} provide,
32209 here is how to use it and customize it further.
32212 @cindex initial RAM disk
32213 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
32214 [#:linux-modules '()] [#:mapped-devices '()] @
32215 [#:keyboard-layout #f] @
32216 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
32217 Return a derivation that builds a raw initrd. @var{file-systems} is
32218 a list of file systems to be mounted by the initrd, possibly in addition to
32219 the root file system specified on the kernel command line via @option{--root}.
32220 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
32221 @var{mapped-devices} is a list of device mappings to realize before
32222 @var{file-systems} are mounted (@pxref{Mapped Devices}).
32223 @var{helper-packages} is a list of packages to be copied in the initrd.
32225 include @code{e2fsck/static} or other packages needed by the initrd to check
32226 the root file system.
32228 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
32229 the desired console keyboard layout. This is done before @var{mapped-devices}
32230 are set up and before @var{file-systems} are mounted such that, should the
32231 user need to enter a passphrase or use the REPL, this happens using the
32232 intended keyboard layout.
32234 When @var{qemu-networking?} is true, set up networking with the standard QEMU
32235 parameters. When @var{virtio?} is true, load additional modules so that the
32236 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
32238 When @var{volatile-root?} is true, the root file system is writable but any changes
32242 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
32243 [#:mapped-devices '()] [#:keyboard-layout #f] @
32244 [#:qemu-networking? #f] [#:volatile-root? #f] @
32245 [#:linux-modules '()]
32246 Return as a file-like object a generic initrd, with kernel
32247 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
32248 mounted by the initrd, possibly in addition to the root file system specified
32249 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
32250 mappings to realize before @var{file-systems} are mounted.
32252 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
32253 the desired console keyboard layout. This is done before @var{mapped-devices}
32254 are set up and before @var{file-systems} are mounted such that, should the
32255 user need to enter a passphrase or use the REPL, this happens using the
32256 intended keyboard layout.
32258 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
32260 The initrd is automatically populated with all the kernel modules necessary
32261 for @var{file-systems} and for the given options. Additional kernel
32262 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
32263 loaded at boot time in the order in which they appear.
32266 Needless to say, the initrds we produce and use embed a
32267 statically-linked Guile, and the initialization program is a Guile
32268 program. That gives a lot of flexibility. The
32269 @code{expression->initrd} procedure builds such an initrd, given the
32270 program to run in that initrd.
32272 @deffn {Scheme Procedure} expression->initrd @var{exp} @
32273 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
32274 Return as a file-like object a Linux initrd (a gzipped cpio archive)
32275 containing @var{guile} and that evaluates @var{exp}, a G-expression,
32276 upon booting. All the derivations referenced by @var{exp} are
32277 automatically copied to the initrd.
32280 @node Bootloader Configuration
32281 @section Bootloader Configuration
32284 @cindex boot loader
32286 The operating system supports multiple bootloaders. The bootloader is
32287 configured using @code{bootloader-configuration} declaration. All the
32288 fields of this structure are bootloader agnostic except for one field,
32289 @code{bootloader} that indicates the bootloader to be configured and
32292 Some of the bootloaders do not honor every field of
32293 @code{bootloader-configuration}. For instance, the extlinux
32294 bootloader does not support themes and thus ignores the @code{theme}
32297 @deftp {Data Type} bootloader-configuration
32298 The type of a bootloader configuration declaration.
32302 @item @code{bootloader}
32303 @cindex EFI, bootloader
32304 @cindex UEFI, bootloader
32305 @cindex BIOS, bootloader
32306 The bootloader to use, as a @code{bootloader} object. For now
32307 @code{grub-bootloader}, @code{grub-efi-bootloader},
32308 @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
32309 @code{u-boot-bootloader} are supported.
32311 @cindex ARM, bootloaders
32312 @cindex AArch64, bootloaders
32313 Available bootloaders are described in @code{(gnu bootloader @dots{})}
32314 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
32315 of bootloaders for a wide range of ARM and AArch64 systems, using the
32316 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
32318 @vindex grub-efi-bootloader
32319 @code{grub-efi-bootloader} allows to boot on modern systems using the
32320 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
32321 use if the installation image contains a @file{/sys/firmware/efi} directory
32322 when you boot it on your system.
32324 @vindex grub-bootloader
32325 @code{grub-bootloader} allows you to boot in particular Intel-based machines
32326 in ``legacy'' BIOS mode.
32328 @vindex grub-efi-netboot-bootloader
32329 @code{grub-efi-netboot-bootloader} allows you to boot your system over network
32330 through TFTP@. In combination with an NFS root file system this allows you to
32331 build a diskless Guix system.
32333 The installation of the @code{grub-efi-netboot-bootloader} generates the content
32334 of the TFTP root directory at @code{target}
32335 (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
32336 You may want to mount your TFTP server directory onto @code{target} to move the
32337 required files to the TFTP server automatically.
32339 If you plan to use an NFS root file system as well (actually if you mount the
32340 store from an NFS share), then the TFTP server needs to serve the file
32341 @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
32342 image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
32343 initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
32344 files from the store will be accessed by GRUB through TFTP with their normal
32345 store path, for example as
32346 @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
32348 Two symlinks are created to make this possible. The first symlink is
32349 @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
32350 @file{../../../boot/grub/grub.cfg},
32351 where @code{target} may be @file{/boot}. In this case the link is not leaving
32352 the served TFTP root directory, but otherwise it does. The second link is
32353 @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
32354 is leaving the served TFTP root directory.
32356 The assumption behind all this is that you have an NFS server exporting the root
32357 file system for your Guix system, and additionally a TFTP server exporting your
32358 @code{target} directory—usually @file{/boot}—from that same root file system for
32359 your Guix system. In this constellation the symlinks will work.
32361 For other constellations you will have to program your own bootloader installer,
32362 which then takes care to make necessary files from the store accessible through
32363 TFTP, for example by copying them into the TFTP root directory at @code{target}.
32365 It is important to note that symlinks pointing outside the TFTP root directory
32366 may need to be allowed in the configuration of your TFTP server. Further the
32367 store link exposes the whole store through TFTP@. Both points need to be
32368 considered carefully for security aspects.
32370 Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
32371 NFS servers, you also need a properly configured DHCP server to make the booting
32372 over netboot possible. For all this we can currently only recommend you to look
32373 for instructions about @acronym{PXE, Preboot eXecution Environment}.
32375 @item @code{target}
32376 This is a string denoting the target onto which to install the
32379 The interpretation depends on the bootloader in question. For
32380 @code{grub-bootloader}, for example, it should be a device name understood by
32381 the bootloader @command{installer} command, such as @code{/dev/sda} or
32382 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
32383 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
32384 system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
32385 @code{target} should be the mount point corresponding to the TFTP root
32386 directory of your TFTP server.
32388 @item @code{menu-entries} (default: @code{()})
32389 A possibly empty list of @code{menu-entry} objects (see below), denoting
32390 entries to appear in the bootloader menu, in addition to the current
32391 system entry and the entry pointing to previous system generations.
32393 @item @code{default-entry} (default: @code{0})
32394 The index of the default boot menu entry. Index 0 is for the entry of the
32397 @item @code{timeout} (default: @code{5})
32398 The number of seconds to wait for keyboard input before booting. Set to
32399 0 to boot immediately, and to -1 to wait indefinitely.
32401 @cindex keyboard layout, for the bootloader
32402 @item @code{keyboard-layout} (default: @code{#f})
32403 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
32404 layout, usually US@tie{}English (``qwerty'').
32406 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
32410 This option is currently ignored by bootloaders other than @code{grub} and
32414 @item @code{theme} (default: @var{#f})
32415 The bootloader theme object describing the theme to use. If no theme
32416 is provided, some bootloaders might use a default theme, that's true
32419 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
32420 The output terminals used for the bootloader boot menu, as a list of
32421 symbols. GRUB accepts the values: @code{console}, @code{serial},
32422 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
32423 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
32424 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
32425 configuration,,, grub,GNU GRUB manual}).
32427 @item @code{terminal-inputs} (default: @code{'()})
32428 The input terminals used for the bootloader boot menu, as a list of
32429 symbols. For GRUB, the default is the native platform terminal as
32430 determined at run-time. GRUB accepts the values: @code{console},
32431 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
32432 @code{usb_keyboard}. This field corresponds to the GRUB variable
32433 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
32436 @item @code{serial-unit} (default: @code{#f})
32437 The serial unit used by the bootloader, as an integer from 0 to 3.
32438 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
32439 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
32441 @item @code{serial-speed} (default: @code{#f})
32442 The speed of the serial interface, as an integer. For GRUB, the
32443 default value is chosen at run-time; currently GRUB chooses
32444 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
32451 Should you want to list additional boot menu entries @i{via} the
32452 @code{menu-entries} field above, you will need to create them with the
32453 @code{menu-entry} form. For example, imagine you want to be able to
32454 boot another distro (hard to imagine!), you can define a menu entry
32459 (label "The Other Distro")
32460 (linux "/boot/old/vmlinux-2.6.32")
32461 (linux-arguments '("root=/dev/sda2"))
32462 (initrd "/boot/old/initrd"))
32467 @deftp {Data Type} menu-entry
32468 The type of an entry in the bootloader menu.
32473 The label to show in the menu---e.g., @code{"GNU"}.
32475 @item @code{linux} (default: @code{#f})
32476 The Linux kernel image to boot, for example:
32479 (file-append linux-libre "/bzImage")
32482 For GRUB, it is also possible to specify a device explicitly in the
32483 file path using GRUB's device naming convention (@pxref{Naming
32484 convention,,, grub, GNU GRUB manual}), for example:
32487 "(hd0,msdos1)/boot/vmlinuz"
32490 If the device is specified explicitly as above, then the @code{device}
32491 field is ignored entirely.
32493 @item @code{linux-arguments} (default: @code{()})
32494 The list of extra Linux kernel command-line arguments---e.g.,
32495 @code{("console=ttyS0")}.
32497 @item @code{initrd} (default: @code{#f})
32498 A G-Expression or string denoting the file name of the initial RAM disk
32499 to use (@pxref{G-Expressions}).
32501 @item @code{device} (default: @code{#f})
32502 The device where the kernel and initrd are to be found---i.e., for GRUB,
32503 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
32505 This may be a file system label (a string), a file system UUID (a
32506 bytevector, @pxref{File Systems}), or @code{#f}, in which case
32507 the bootloader will search the device containing the file specified by
32508 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
32509 must @emph{not} be an OS device name such as @file{/dev/sda1}.
32511 @item @code{multiboot-kernel} (default: @code{#f})
32512 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
32513 manual}). When this field is set, a Multiboot menu-entry is generated.
32517 (file-append mach "/boot/gnumach")
32520 @item @code{multiboot-arguments} (default: @code{()})
32521 The list of extra command-line arguments for the multiboot-kernel.
32523 @item @code{multiboot-modules} (default: @code{()})
32524 The list of commands for loading Multiboot modules. For example:
32527 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
32529 (list (file-append libc "/lib/ld.so.1") "exec"
32539 @c FIXME: Write documentation once it's stable.
32540 For now only GRUB has theme support. GRUB themes are created using
32541 the @code{grub-theme} form, which is not fully documented yet.
32543 @deftp {Data Type} grub-theme
32544 Data type representing the configuration of the GRUB theme.
32547 @item @code{gfxmode} (default: @code{'("auto")})
32548 The GRUB @code{gfxmode} to set (a list of screen resolution strings,
32549 @pxref{gfxmode,,, grub, GNU GRUB manual}).
32553 @deffn {Scheme Procedure} grub-theme
32554 Return the default GRUB theme used by the operating system if no
32555 @code{theme} field is specified in @code{bootloader-configuration}
32558 It comes with a fancy background image displaying the GNU and Guix
32562 For example, to override the default resolution, you may use something
32567 (bootloader-configuration
32570 (inherit (grub-theme))
32571 (gfxmode '("1024x786x32" "auto"))))))
32574 @node Invoking guix system
32575 @section Invoking @code{guix system}
32577 Once you have written an operating system declaration as seen in the
32578 previous section, it can be @dfn{instantiated} using the @command{guix
32579 system} command. The synopsis is:
32582 guix system @var{options}@dots{} @var{action} @var{file}
32585 @var{file} must be the name of a file containing an
32586 @code{operating-system} declaration. @var{action} specifies how the
32587 operating system is instantiated. Currently the following values are
32592 Display available service type definitions that match the given regular
32593 expressions, sorted by relevance:
32599 $ guix system search console
32600 name: console-fonts
32601 location: gnu/services/base.scm:806:2
32602 extends: shepherd-root
32603 description: Install the given fonts on the specified ttys (fonts are per
32604 + virtual console on GNU/Linux). The value of this service is a list of
32605 + tty/font pairs. The font can be the name of a font provided by the `kbd'
32606 + package or any valid argument to `setfont', as in this example:
32608 + '(("tty1" . "LatGrkCyr-8x16")
32609 + ("tty2" . (file-append
32611 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
32612 + ("tty3" . (file-append
32614 + "/share/consolefonts/ter-132n"))) ; for HDPI
32618 location: gnu/services/base.scm:1190:2
32619 extends: shepherd-root
32620 description: Provide console login using the `mingetty' program.
32624 location: gnu/services/base.scm:860:2
32626 description: Provide a console log-in service as specified by its
32627 + configuration value, a `login-configuration' object.
32633 As for @command{guix package --search}, the result is written in
32634 @code{recutils} format, which makes it easy to filter the output
32635 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
32638 Build the operating system described in @var{file}, activate it, and
32639 switch to it@footnote{This action (and the related actions
32640 @code{switch-generation} and @code{roll-back}) are usable only on
32641 systems already running Guix System.}.
32644 @c The paragraph below refers to the problem discussed at
32645 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
32646 It is highly recommended to run @command{guix pull} once before you run
32647 @command{guix system reconfigure} for the first time (@pxref{Invoking
32648 guix pull}). Failing to do that you would see an older version of Guix
32649 once @command{reconfigure} has completed.
32652 This effects all the configuration specified in @var{file}: user
32653 accounts, system services, global package list, setuid programs, etc.
32654 The command starts system services specified in @var{file} that are not
32655 currently running; if a service is currently running this command will
32656 arrange for it to be upgraded the next time it is stopped (e.g.@: by
32657 @code{herd stop X} or @code{herd restart X}).
32659 This command creates a new generation whose number is one greater than
32660 the current generation (as reported by @command{guix system
32661 list-generations}). If that generation already exists, it will be
32662 overwritten. This behavior mirrors that of @command{guix package}
32663 (@pxref{Invoking guix package}).
32665 It also adds a bootloader menu entry for the new OS configuration,
32666 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
32667 entries for older configurations to a submenu, allowing you to choose
32668 an older system generation at boot time should you need it.
32670 @cindex provenance tracking, of the operating system
32671 Upon completion, the new system is deployed under
32672 @file{/run/current-system}. This directory contains @dfn{provenance
32673 meta-data}: the list of channels in use (@pxref{Channels}) and
32674 @var{file} itself, when available. You can view it by running:
32677 guix system describe
32680 This information is useful should you later want to inspect how this
32681 particular generation was built. In fact, assuming @var{file} is
32682 self-contained, you can later rebuild generation @var{n} of your
32683 operating system with:
32686 guix time-machine \
32687 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
32688 system reconfigure \
32689 /var/guix/profiles/system-@var{n}-link/configuration.scm
32692 You can think of it as some sort of built-in version control! Your
32693 system is not just a binary artifact: @emph{it carries its own source}.
32694 @xref{Service Reference, @code{provenance-service-type}}, for more
32695 information on provenance tracking.
32697 By default, @command{reconfigure} @emph{prevents you from downgrading
32698 your system}, which could (re)introduce security vulnerabilities and
32699 also cause problems with ``stateful'' services such as database
32700 management systems. You can override that behavior by passing
32701 @option{--allow-downgrades}.
32703 @item switch-generation
32704 @cindex generations
32705 Switch to an existing system generation. This action atomically
32706 switches the system profile to the specified system generation. It
32707 also rearranges the system's existing bootloader menu entries. It
32708 makes the menu entry for the specified system generation the default,
32709 and it moves the entries for the other generations to a submenu, if
32710 supported by the bootloader being used. The next time the system
32711 boots, it will use the specified system generation.
32713 The bootloader itself is not being reinstalled when using this
32714 command. Thus, the installed bootloader is used with an updated
32715 configuration file.
32717 The target generation can be specified explicitly by its generation
32718 number. For example, the following invocation would switch to system
32722 guix system switch-generation 7
32725 The target generation can also be specified relative to the current
32726 generation with the form @code{+N} or @code{-N}, where @code{+3} means
32727 ``3 generations ahead of the current generation,'' and @code{-1} means
32728 ``1 generation prior to the current generation.'' When specifying a
32729 negative value such as @code{-1}, you must precede it with @code{--} to
32730 prevent it from being parsed as an option. For example:
32733 guix system switch-generation -- -1
32736 Currently, the effect of invoking this action is @emph{only} to switch
32737 the system profile to an existing generation and rearrange the
32738 bootloader menu entries. To actually start using the target system
32739 generation, you must reboot after running this action. In the future,
32740 it will be updated to do the same things as @command{reconfigure},
32741 like activating and deactivating services.
32743 This action will fail if the specified generation does not exist.
32746 @cindex rolling back
32747 Switch to the preceding system generation. The next time the system
32748 boots, it will use the preceding system generation. This is the inverse
32749 of @command{reconfigure}, and it is exactly the same as invoking
32750 @command{switch-generation} with an argument of @code{-1}.
32752 Currently, as with @command{switch-generation}, you must reboot after
32753 running this action to actually start using the preceding system
32756 @item delete-generations
32757 @cindex deleting system generations
32758 @cindex saving space
32759 Delete system generations, making them candidates for garbage collection
32760 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
32763 This works in the same way as @samp{guix package --delete-generations}
32764 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
32765 arguments, all system generations but the current one are deleted:
32768 guix system delete-generations
32771 You can also select the generations you want to delete. The example below
32772 deletes all the system generations that are more than two month old:
32775 guix system delete-generations 2m
32778 Running this command automatically reinstalls the bootloader with an updated
32779 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
32780 longer lists the generations that have been deleted.
32783 Build the derivation of the operating system, which includes all the
32784 configuration files and programs needed to boot and run the system.
32785 This action does not actually install anything.
32788 Populate the given directory with all the files necessary to run the
32789 operating system specified in @var{file}. This is useful for first-time
32790 installations of Guix System. For instance:
32793 guix system init my-os-config.scm /mnt
32796 copies to @file{/mnt} all the store items required by the configuration
32797 specified in @file{my-os-config.scm}. This includes configuration
32798 files, packages, and so on. It also creates other essential files
32799 needed for the system to operate correctly---e.g., the @file{/etc},
32800 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
32802 This command also installs bootloader on the target specified in
32803 @file{my-os-config}, unless the @option{--no-bootloader} option was
32807 @cindex virtual machine
32809 @anchor{guix system vm}
32810 Build a virtual machine that contains the operating system declared in
32811 @var{file}, and return a script to run that virtual machine (VM).
32814 The @code{vm} action and others below
32815 can use KVM support in the Linux-libre kernel. Specifically, if the
32816 machine has hardware virtualization support, the corresponding
32817 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
32818 must exist and be readable and writable by the user and by the
32819 build users of the daemon (@pxref{Build Environment Setup}).
32822 Arguments given to the script are passed to QEMU as in the example
32823 below, which enables networking and requests 1@tie{}GiB of RAM for the
32827 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
32830 The VM shares its store with the host system.
32832 Additional file systems can be shared between the host and the VM using
32833 the @option{--share} and @option{--expose} command-line options: the former
32834 specifies a directory to be shared with write access, while the latter
32835 provides read-only access to the shared directory.
32837 The example below creates a VM in which the user's home directory is
32838 accessible read-only, and where the @file{/exchange} directory is a
32839 read-write mapping of @file{$HOME/tmp} on the host:
32842 guix system vm my-config.scm \
32843 --expose=$HOME --share=$HOME/tmp=/exchange
32846 On GNU/Linux, the default is to boot directly to the kernel; this has
32847 the advantage of requiring only a very tiny root disk image since the
32848 store of the host can then be mounted.
32850 The @option{--full-boot} option forces a complete boot sequence, starting
32851 with the bootloader. This requires more disk space since a root image
32852 containing at least the kernel, initrd, and bootloader data files must
32853 be created. The @option{--image-size} option can be used to specify the
32856 @cindex System images, creation in various formats
32857 @cindex Creating system images in various formats
32859 @itemx docker-image
32860 Return a virtual machine, disk image, or Docker image of the operating
32861 system declared in @var{file} that stands alone. By default,
32862 @command{guix system} estimates the size of the image needed to store
32863 the system, but you can use the @option{--image-size} option to specify
32864 a value. Docker images are built to contain exactly what they need, so
32865 the @option{--image-size} option is ignored in the case of
32866 @code{docker-image}.
32868 @cindex image, creating disk images
32869 The @code{image} command can produce various image types. The
32870 image type can be selected using the @option{--image-type} option. It
32871 defaults to @code{efi-raw}. When its value is @code{iso9660}, the
32872 @option{--label} option can be used to specify a volume ID with
32873 @code{image}. By default, the root file system of a disk image is
32874 mounted non-volatile; the @option{--volatile} option can be provided to
32875 make it volatile instead. When using @code{image}, the bootloader
32876 installed on the generated image is taken from the provided
32877 @code{operating-system} definition. The following example demonstrates
32878 how to generate an image that uses the @code{grub-efi-bootloader}
32879 bootloader and boot it with QEMU:
32882 image=$(guix system image --image-type=qcow2 \
32883 gnu/system/examples/lightweight-desktop.tmpl)
32884 cp $image /tmp/my-image.qcow2
32885 chmod +w /tmp/my-image.qcow2
32886 qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
32887 -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
32890 When using the @code{efi-raw} image type, a raw disk image is produced;
32891 it can be copied as is to a USB stick, for instance. Assuming
32892 @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
32893 the image to it using the following command:
32896 # dd if=$(guix system image my-os.scm) of=/dev/sdc status=progress
32899 The @code{--list-image-types} command lists all the available image
32902 @cindex creating virtual machine images
32903 When using the @code{qcow2} image type, the returned image is in qcow2
32904 format, which the QEMU emulator can efficiently use. @xref{Running Guix
32905 in a VM}, for more information on how to run the image in a virtual
32906 machine. The @code{grub-bootloader} bootloader is always used
32907 independently of what is declared in the @code{operating-system} file
32908 passed as argument. This is to make it easier to work with QEMU, which
32909 uses the SeaBIOS BIOS by default, expecting a bootloader to be installed
32910 in the Master Boot Record (MBR).
32912 @cindex docker-image, creating docker images
32913 When using @code{docker-image}, a Docker image is produced. Guix builds
32914 the image from scratch, not from a pre-existing Docker base image. As a
32915 result, it contains @emph{exactly} what you define in the operating
32916 system configuration file. You can then load the image and launch a
32917 Docker container using commands like the following:
32920 image_id="$(docker load < guix-system-docker-image.tar.gz)"
32921 container_id="$(docker create $image_id)"
32922 docker start $container_id
32925 This command starts a new Docker container from the specified image. It
32926 will boot the Guix system in the usual manner, which means it will
32927 start any services you have defined in the operating system
32928 configuration. You can get an interactive shell running in the container
32929 using @command{docker exec}:
32932 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
32935 Depending on what you run in the Docker container, it
32936 may be necessary to give the container additional permissions. For
32937 example, if you intend to build software using Guix inside of the Docker
32938 container, you may need to pass the @option{--privileged} option to
32939 @code{docker create}.
32941 Last, the @option{--network} option applies to @command{guix system
32942 docker-image}: it produces an image where network is supposedly shared
32943 with the host, and thus without services like nscd or NetworkManager.
32946 Return a script to run the operating system declared in @var{file}
32947 within a container. Containers are a set of lightweight isolation
32948 mechanisms provided by the kernel Linux-libre. Containers are
32949 substantially less resource-demanding than full virtual machines since
32950 the kernel, shared objects, and other resources can be shared with the
32951 host system; this also means they provide thinner isolation.
32953 Currently, the script must be run as root in order to support more than
32954 a single user and group. The container shares its store with the host
32957 As with the @code{vm} action (@pxref{guix system vm}), additional file
32958 systems to be shared between the host and container can be specified
32959 using the @option{--share} and @option{--expose} options:
32962 guix system container my-config.scm \
32963 --expose=$HOME --share=$HOME/tmp=/exchange
32967 This option requires Linux-libre 3.19 or newer.
32972 @var{options} can contain any of the common build options (@pxref{Common
32973 Build Options}). In addition, @var{options} can contain one of the
32977 @item --expression=@var{expr}
32978 @itemx -e @var{expr}
32979 Consider the operating-system @var{expr} evaluates to.
32980 This is an alternative to specifying a file which evaluates to an
32982 This is used to generate the Guix system installer @pxref{Building the
32983 Installation Image}).
32985 @item --system=@var{system}
32986 @itemx -s @var{system}
32987 Attempt to build for @var{system} instead of the host system type.
32988 This works as per @command{guix build} (@pxref{Invoking guix build}).
32992 Return the derivation file name of the given operating system without
32995 @cindex provenance tracking, of the operating system
32996 @item --save-provenance
32997 As discussed above, @command{guix system init} and @command{guix system
32998 reconfigure} always save provenance information @i{via} a dedicated
32999 service (@pxref{Service Reference, @code{provenance-service-type}}).
33000 However, other commands don't do that by default. If you wish to, say,
33001 create a virtual machine image that contains provenance information, you
33005 guix system image -t qcow2 --save-provenance config.scm
33008 That way, the resulting image will effectively ``embed its own source''
33009 in the form of meta-data in @file{/run/current-system}. With that
33010 information, one can rebuild the image to make sure it really contains
33011 what it pretends to contain; or they could use that to derive a variant
33014 @item --image-type=@var{type}
33015 @itemx -t @var{type}
33016 For the @code{image} action, create an image with given @var{type}.
33018 When this option is omitted, @command{guix system} uses the
33019 @code{efi-raw} image type.
33021 @cindex ISO-9660 format
33022 @cindex CD image format
33023 @cindex DVD image format
33024 @option{--image-type=iso9660} produces an ISO-9660 image, suitable
33025 for burning on CDs and DVDs.
33027 @item --image-size=@var{size}
33028 For the @code{image} action, create an image of the given @var{size}.
33029 @var{size} may be a number of bytes, or it may include a unit as a
33030 suffix (@pxref{Block size, size specifications,, coreutils, GNU
33033 When this option is omitted, @command{guix system} computes an estimate
33034 of the image size as a function of the size of the system declared in
33039 For the @code{container} action, allow containers to access the host network,
33040 that is, do not create a network namespace.
33042 @item --root=@var{file}
33043 @itemx -r @var{file}
33044 Make @var{file} a symlink to the result, and register it as a garbage
33047 @item --skip-checks
33048 Skip pre-installation safety checks.
33050 By default, @command{guix system init} and @command{guix system
33051 reconfigure} perform safety checks: they make sure the file systems that
33052 appear in the @code{operating-system} declaration actually exist
33053 (@pxref{File Systems}), and that any Linux kernel modules that may be
33054 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
33055 RAM Disk}). Passing this option skips these tests altogether.
33057 @item --allow-downgrades
33058 Instruct @command{guix system reconfigure} to allow system downgrades.
33060 By default, @command{reconfigure} prevents you from downgrading your
33061 system. It achieves that by comparing the provenance info of your
33062 system (shown by @command{guix system describe}) with that of your
33063 @command{guix} command (shown by @command{guix describe}). If the
33064 commits for @command{guix} are not descendants of those used for your
33065 system, @command{guix system reconfigure} errors out. Passing
33066 @option{--allow-downgrades} allows you to bypass these checks.
33069 Make sure you understand its security implications before using
33070 @option{--allow-downgrades}.
33074 @cindex on-error strategy
33075 @cindex error strategy
33076 @item --on-error=@var{strategy}
33077 Apply @var{strategy} when an error occurs when reading @var{file}.
33078 @var{strategy} may be one of the following:
33081 @item nothing-special
33082 Report the error concisely and exit. This is the default strategy.
33085 Likewise, but also display a backtrace.
33088 Report the error and enter Guile's debugger. From there, you can run
33089 commands such as @code{,bt} to get a backtrace, @code{,locals} to
33090 display local variable values, and more generally inspect the state of the
33091 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
33092 a list of available debugging commands.
33096 Once you have built, configured, re-configured, and re-re-configured
33097 your Guix installation, you may find it useful to list the operating
33098 system generations available on disk---and that you can choose from the
33099 bootloader boot menu:
33104 Describe the current system generation: its file name, the kernel and
33105 bootloader used, etc., as well as provenance information when available.
33107 @item list-generations
33108 List a summary of each generation of the operating system available on
33109 disk, in a human-readable way. This is similar to the
33110 @option{--list-generations} option of @command{guix package}
33111 (@pxref{Invoking guix package}).
33113 Optionally, one can specify a pattern, with the same syntax that is used
33114 in @command{guix package --list-generations}, to restrict the list of
33115 generations displayed. For instance, the following command displays
33116 generations that are up to 10 days old:
33119 $ guix system list-generations 10d
33124 The @command{guix system} command has even more to offer! The following
33125 sub-commands allow you to visualize how your system services relate to
33128 @anchor{system-extension-graph}
33131 @item extension-graph
33132 Emit to standard output the @dfn{service
33133 extension graph} of the operating system defined in @var{file}
33134 (@pxref{Service Composition}, for more information on service
33135 extensions). By default the output is in Dot/Graphviz format, but you
33136 can choose a different format with @option{--graph-backend}, as with
33137 @command{guix graph} (@pxref{Invoking guix graph, @option{--backend}}):
33142 $ guix system extension-graph @var{file} | xdot -
33145 shows the extension relations among services.
33147 @anchor{system-shepherd-graph}
33148 @item shepherd-graph
33149 Emit to standard output the @dfn{dependency
33150 graph} of shepherd services of the operating system defined in
33151 @var{file}. @xref{Shepherd Services}, for more information and for an
33154 Again, the default output format is Dot/Graphviz, but you can pass
33155 @option{--graph-backend} to select a different one.
33159 @node Invoking guix deploy
33160 @section Invoking @code{guix deploy}
33162 We've already seen @code{operating-system} declarations used to manage a
33163 machine's configuration locally. Suppose you need to configure multiple
33164 machines, though---perhaps you're managing a service on the web that's
33165 comprised of several servers. @command{guix deploy} enables you to use those
33166 same @code{operating-system} declarations to manage multiple remote hosts at
33167 once as a logical ``deployment''.
33170 The functionality described in this section is still under development
33171 and is subject to change. Get in touch with us on
33172 @email{guix-devel@@gnu.org}!
33176 guix deploy @var{file}
33179 Such an invocation will deploy the machines that the code within @var{file}
33180 evaluates to. As an example, @var{file} might contain a definition like this:
33183 ;; This is a Guix deployment of a "bare bones" setup, with
33184 ;; no X11 display server, to a machine with an SSH daemon
33185 ;; listening on localhost:2222. A configuration such as this
33186 ;; may be appropriate for virtual machine with ports
33187 ;; forwarded to the host's loopback interface.
33189 (use-service-modules networking ssh)
33190 (use-package-modules bootloaders)
33194 (host-name "gnu-deployed")
33195 (timezone "Etc/UTC")
33196 (bootloader (bootloader-configuration
33197 (bootloader grub-bootloader)
33198 (target "/dev/vda")
33199 (terminal-outputs '(console))))
33200 (file-systems (cons (file-system
33202 (device "/dev/vda1")
33204 %base-file-systems))
33206 (append (list (service dhcp-client-service-type)
33207 (service openssh-service-type
33208 (openssh-configuration
33209 (permit-root-login #t)
33210 (allow-empty-passwords? #t))))
33214 (operating-system %system)
33215 (environment managed-host-environment-type)
33216 (configuration (machine-ssh-configuration
33217 (host-name "localhost")
33218 (system "x86_64-linux")
33220 (identity "./id_rsa")
33224 The file should evaluate to a list of @var{machine} objects. This example,
33225 upon being deployed, will create a new generation on the remote system
33226 realizing the @code{operating-system} declaration @code{%system}.
33227 @code{environment} and @code{configuration} specify how the machine should be
33228 provisioned---that is, how the computing resources should be created and
33229 managed. The above example does not create any resources, as a
33230 @code{'managed-host} is a machine that is already running the Guix system and
33231 available over the network. This is a particularly simple case; a more
33232 complex deployment may involve, for example, starting virtual machines through
33233 a Virtual Private Server (VPS) provider. In such a case, a different
33234 @var{environment} type would be used.
33236 Do note that you first need to generate a key pair on the coordinator machine
33237 to allow the daemon to export signed archives of files from the store
33238 (@pxref{Invoking guix archive}), though this step is automatic on Guix
33242 # guix archive --generate-key
33246 Each target machine must authorize the key of the master machine so that it
33247 accepts store items it receives from the coordinator:
33250 # guix archive --authorize < coordinator-public-key.txt
33253 @code{user}, in this example, specifies the name of the user account to log in
33254 as to perform the deployment. Its default value is @code{root}, but root
33255 login over SSH may be forbidden in some cases. To work around this,
33256 @command{guix deploy} can log in as an unprivileged user and employ
33257 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
33258 currently installed on the remote and can be invoked non-interactively as
33259 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
33260 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
33261 be accomplished with the following operating system configuration snippet:
33265 (gnu system)) ;for %sudoers-specification
33267 (define %user "username")
33272 (plain-file "sudoers"
33273 (string-append (plain-file-content %sudoers-specification)
33274 (format #f "~a ALL = NOPASSWD: ALL~%"
33279 For more information regarding the format of the @file{sudoers} file,
33280 consult @command{man sudoers}.
33282 @deftp {Data Type} machine
33283 This is the data type representing a single machine in a heterogeneous Guix
33287 @item @code{operating-system}
33288 The object of the operating system configuration to deploy.
33290 @item @code{environment}
33291 An @code{environment-type} describing how the machine should be provisioned.
33293 @item @code{configuration} (default: @code{#f})
33294 An object describing the configuration for the machine's @code{environment}.
33295 If the @code{environment} has a default configuration, @code{#f} may be used.
33296 If @code{#f} is used for an environment with no default configuration,
33297 however, an error will be thrown.
33301 @deftp {Data Type} machine-ssh-configuration
33302 This is the data type representing the SSH client parameters for a machine
33303 with an @code{environment} of @code{managed-host-environment-type}.
33306 @item @code{host-name}
33307 @item @code{build-locally?} (default: @code{#t})
33308 If false, system derivations will be built on the machine being deployed to.
33309 @item @code{system}
33310 The system type describing the architecture of the machine being deployed
33311 to---e.g., @code{"x86_64-linux"}.
33312 @item @code{authorize?} (default: @code{#t})
33313 If true, the coordinator's signing key will be added to the remote's ACL
33315 @item @code{port} (default: @code{22})
33316 @item @code{user} (default: @code{"root"})
33317 @item @code{identity} (default: @code{#f})
33318 If specified, the path to the SSH private key to use to authenticate with the
33321 @item @code{host-key} (default: @code{#f})
33322 This should be the SSH host key of the machine, which looks like this:
33325 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
33328 When @code{host-key} is @code{#f}, the server is authenticated against
33329 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
33332 @item @code{allow-downgrades?} (default: @code{#f})
33333 Whether to allow potential downgrades.
33335 Like @command{guix system reconfigure}, @command{guix deploy} compares
33336 the channel commits currently deployed on the remote host (as returned
33337 by @command{guix system describe}) to those currently in use (as
33338 returned by @command{guix describe}) to determine whether commits
33339 currently in use are descendants of those deployed. When this is not
33340 the case and @code{allow-downgrades?} is false, it raises an error.
33341 This ensures you do not accidentally downgrade remote machines.
33345 @deftp {Data Type} digital-ocean-configuration
33346 This is the data type describing the Droplet that should be created for a
33347 machine with an @code{environment} of @code{digital-ocean-environment-type}.
33350 @item @code{ssh-key}
33351 The path to the SSH private key to use to authenticate with the remote
33352 host. In the future, this field may not exist.
33354 A list of string ``tags'' that uniquely identify the machine. Must be given
33355 such that no two machines in the deployment have the same set of tags.
33356 @item @code{region}
33357 A Digital Ocean region slug, such as @code{"nyc3"}.
33359 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
33360 @item @code{enable-ipv6?}
33361 Whether or not the droplet should be created with IPv6 networking.
33365 @node Running Guix in a VM
33366 @section Running Guix in a Virtual Machine
33368 @cindex virtual machine
33369 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
33371 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
33372 This image is a compressed image in QCOW format. You will first need to
33373 decompress with @command{xz -d}, and then you can pass it to an emulator such
33374 as QEMU (see below for details).
33376 This image boots the Xfce graphical environment and it contains some
33377 commonly used tools. You can install more software in the image by running
33378 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
33379 also reconfigure the system based on its initial configuration file available
33380 as @file{/run/current-system/configuration.scm} (@pxref{Using the
33381 Configuration System}).
33383 Instead of using this pre-built image, one can also build their own virtual
33384 machine image using @command{guix system vm-image} (@pxref{Invoking guix
33385 system}). The returned image is in qcow2 format, which the
33386 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
33389 If you built your own image, you must copy it out of the store
33390 (@pxref{The Store}) and give yourself permission to write to the copy
33391 before you can use it. When invoking QEMU, you must choose a system
33392 emulator that is suitable for your hardware platform. Here is a minimal
33393 QEMU invocation that will boot the result of @command{guix system
33394 image -t qcow2} on x86_64 hardware:
33397 $ qemu-system-x86_64 \
33398 -nic user,model=virtio-net-pci \
33399 -enable-kvm -m 1024 \
33400 -device virtio-blk,drive=myhd \
33401 -drive if=none,file=/tmp/qemu-image,id=myhd
33404 Here is what each of these options means:
33407 @item qemu-system-x86_64
33408 This specifies the hardware platform to emulate. This should match the
33411 @item -nic user,model=virtio-net-pci
33412 Enable the unprivileged user-mode network stack. The guest OS can
33413 access the host but not vice versa. This is the simplest way to get the
33414 guest OS online. @code{model} specifies which network device to emulate:
33415 @code{virtio-net-pci} is a special device made for virtualized operating
33416 systems and recommended for most uses. Assuming your hardware platform is
33417 x86_64, you can get a list of available NIC models by running
33418 @command{qemu-system-x86_64 -nic model=help}.
33421 If your system has hardware virtualization extensions, enabling the
33422 virtual machine support (KVM) of the Linux kernel will make things run
33425 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
33427 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
33428 which may be insufficient for some operations.
33430 @item -device virtio-blk,drive=myhd
33431 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
33432 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
33433 better performance than if it were emulating a complete disk drive. See the
33434 QEMU and KVM documentation for more info.
33436 @item -drive if=none,file=/tmp/qemu-image,id=myhd
33437 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
33438 store of the ``myhd'' drive.
33441 The default @command{run-vm.sh} script that is returned by an invocation of
33442 @command{guix system vm} does not add a @command{-nic user} flag by default.
33443 To get network access from within the vm add the @code{(dhcp-client-service)}
33444 to your system definition and start the VM using
33445 @command{$(guix system vm config.scm) -nic user}. An important caveat of using
33446 @command{-nic user} for networking is that @command{ping} will not work, because
33447 it uses the ICMP protocol. You'll have to use a different command to check for
33448 network connectivity, for example @command{guix download}.
33450 @subsection Connecting Through SSH
33454 To enable SSH inside a VM you need to add an SSH server like
33455 @code{openssh-service-type} to your VM (@pxref{Networking Services,
33456 @code{openssh-service-type}}). In addition you need to forward the SSH port,
33457 22 by default, to the host. You can do this with
33460 $(guix system vm config.scm) -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
33463 To connect to the VM you can run
33466 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
33469 The @command{-p} tells @command{ssh} the port you want to connect to.
33470 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
33471 every time you modify your @command{config.scm} file and the
33472 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
33473 connection to an unknown host every time you connect.
33475 @subsection Using @command{virt-viewer} with Spice
33477 As an alternative to the default @command{qemu} graphical client you can
33478 use the @command{remote-viewer} from the @command{virt-viewer} package. To
33479 connect pass the @command{-spice port=5930,disable-ticketing} flag to
33480 @command{qemu}. See previous section for further information on how to do this.
33482 Spice also allows you to do some nice stuff like share your clipboard with your
33483 VM@. To enable that you'll also have to pass the following flags to @command{qemu}:
33486 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
33487 -chardev spicevmc,name=vdagent,id=vdagent
33488 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
33489 name=com.redhat.spice.0
33492 You'll also need to add the @code{(spice-vdagent-service)} to your
33493 system definition (@pxref{Miscellaneous Services, Spice service}).
33495 @node Defining Services
33496 @section Defining Services
33498 The previous sections show the available services and how one can combine
33499 them in an @code{operating-system} declaration. But how do we define
33500 them in the first place? And what is a service anyway?
33503 * Service Composition:: The model for composing services.
33504 * Service Types and Services:: Types and services.
33505 * Service Reference:: API reference.
33506 * Shepherd Services:: A particular type of service.
33509 @node Service Composition
33510 @subsection Service Composition
33514 Here we define a @dfn{service} as, broadly, something that extends the
33515 functionality of the operating system. Often a service is a process---a
33516 @dfn{daemon}---started when the system boots: a secure shell server, a
33517 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
33518 whose execution can be triggered by another daemon---e.g., an FTP server
33519 started by @command{inetd} or a D-Bus service activated by
33520 @command{dbus-daemon}. Occasionally, a service does not map to a
33521 daemon. For instance, the ``account'' service collects user accounts
33522 and makes sure they exist when the system runs; the ``udev'' service
33523 collects device management rules and makes them available to the eudev
33524 daemon; the @file{/etc} service populates the @file{/etc} directory
33527 @cindex service extensions
33528 Guix system services are connected by @dfn{extensions}. For instance, the
33529 secure shell service @emph{extends} the Shepherd---the
33530 initialization system, running as PID@tie{}1---by giving it the command
33531 lines to start and stop the secure shell daemon (@pxref{Networking
33532 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
33533 service by passing it its @file{.service} specification, and extends the
33534 udev service by passing it device management rules (@pxref{Desktop
33535 Services, @code{upower-service}}); the Guix daemon service extends the
33536 Shepherd by passing it the command lines to start and stop the daemon,
33537 and extends the account service by passing it a list of required build
33538 user accounts (@pxref{Base Services}).
33540 All in all, services and their ``extends'' relations form a directed
33541 acyclic graph (DAG). If we represent services as boxes and extensions
33542 as arrows, a typical system might provide something like this:
33544 @image{images/service-graph,,5in,Typical service extension graph.}
33546 @cindex system service
33547 At the bottom, we see the @dfn{system service}, which produces the
33548 directory containing everything to run and boot the system, as returned
33549 by the @command{guix system build} command. @xref{Service Reference},
33550 to learn about the other service types shown here.
33551 @xref{system-extension-graph, the @command{guix system extension-graph}
33552 command}, for information on how to generate this representation for a
33553 particular operating system definition.
33555 @cindex service types
33556 Technically, developers can define @dfn{service types} to express these
33557 relations. There can be any number of services of a given type on the
33558 system---for instance, a system running two instances of the GNU secure
33559 shell server (lsh) has two instances of @code{lsh-service-type}, with
33560 different parameters.
33562 The following section describes the programming interface for service
33563 types and services.
33565 @node Service Types and Services
33566 @subsection Service Types and Services
33568 A @dfn{service type} is a node in the DAG described above. Let us start
33569 with a simple example, the service type for the Guix build daemon
33570 (@pxref{Invoking guix-daemon}):
33573 (define guix-service-type
33577 (list (service-extension shepherd-root-service-type guix-shepherd-service)
33578 (service-extension account-service-type guix-accounts)
33579 (service-extension activation-service-type guix-activation)))
33580 (default-value (guix-configuration))))
33584 It defines three things:
33588 A name, whose sole purpose is to make inspection and debugging easier.
33591 A list of @dfn{service extensions}, where each extension designates the
33592 target service type and a procedure that, given the parameters of the
33593 service, returns a list of objects to extend the service of that type.
33595 Every service type has at least one service extension. The only
33596 exception is the @dfn{boot service type}, which is the ultimate service.
33599 Optionally, a default value for instances of this type.
33602 In this example, @code{guix-service-type} extends three services:
33605 @item shepherd-root-service-type
33606 The @code{guix-shepherd-service} procedure defines how the Shepherd
33607 service is extended. Namely, it returns a @code{<shepherd-service>}
33608 object that defines how @command{guix-daemon} is started and stopped
33609 (@pxref{Shepherd Services}).
33611 @item account-service-type
33612 This extension for this service is computed by @code{guix-accounts},
33613 which returns a list of @code{user-group} and @code{user-account}
33614 objects representing the build user accounts (@pxref{Invoking
33617 @item activation-service-type
33618 Here @code{guix-activation} is a procedure that returns a gexp, which is
33619 a code snippet to run at ``activation time''---e.g., when the service is
33623 A service of this type is instantiated like this:
33626 (service guix-service-type
33627 (guix-configuration
33629 (extra-options '("--gc-keep-derivations"))))
33632 The second argument to the @code{service} form is a value representing
33633 the parameters of this specific service instance.
33634 @xref{guix-configuration-type, @code{guix-configuration}}, for
33635 information about the @code{guix-configuration} data type. When the
33636 value is omitted, the default value specified by
33637 @code{guix-service-type} is used:
33640 (service guix-service-type)
33643 @code{guix-service-type} is quite simple because it extends other
33644 services but is not extensible itself.
33646 @c @subsubsubsection Extensible Service Types
33648 The service type for an @emph{extensible} service looks like this:
33651 (define udev-service-type
33652 (service-type (name 'udev)
33654 (list (service-extension shepherd-root-service-type
33655 udev-shepherd-service)))
33657 (compose concatenate) ;concatenate the list of rules
33658 (extend (lambda (config rules)
33660 (($ <udev-configuration> udev initial-rules)
33661 (udev-configuration
33662 (udev udev) ;the udev package to use
33663 (rules (append initial-rules rules)))))))))
33666 This is the service type for the
33667 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
33668 management daemon}. Compared to the previous example, in addition to an
33669 extension of @code{shepherd-root-service-type}, we see two new fields:
33673 This is the procedure to @dfn{compose} the list of extensions to
33674 services of this type.
33676 Services can extend the udev service by passing it lists of rules; we
33677 compose those extensions simply by concatenating them.
33680 This procedure defines how the value of the service is @dfn{extended} with
33681 the composition of the extensions.
33683 Udev extensions are composed into a list of rules, but the udev service
33684 value is itself a @code{<udev-configuration>} record. So here, we
33685 extend that record by appending the list of rules it contains to the
33686 list of contributed rules.
33689 This is a string giving an overview of the service type. The string can
33690 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
33691 @command{guix system search} command searches these strings and displays
33692 them (@pxref{Invoking guix system}).
33695 There can be only one instance of an extensible service type such as
33696 @code{udev-service-type}. If there were more, the
33697 @code{service-extension} specifications would be ambiguous.
33699 Still here? The next section provides a reference of the programming
33700 interface for services.
33702 @node Service Reference
33703 @subsection Service Reference
33705 We have seen an overview of service types (@pxref{Service Types and
33706 Services}). This section provides a reference on how to manipulate
33707 services and service types. This interface is provided by the
33708 @code{(gnu services)} module.
33710 @deffn {Scheme Procedure} service @var{type} [@var{value}]
33711 Return a new service of @var{type}, a @code{<service-type>} object (see
33712 below). @var{value} can be any object; it represents the parameters of
33713 this particular service instance.
33715 When @var{value} is omitted, the default value specified by @var{type}
33716 is used; if @var{type} does not specify a default value, an error is
33719 For instance, this:
33722 (service openssh-service-type)
33726 is equivalent to this:
33729 (service openssh-service-type
33730 (openssh-configuration))
33733 In both cases the result is an instance of @code{openssh-service-type}
33734 with the default configuration.
33737 @deffn {Scheme Procedure} service? @var{obj}
33738 Return true if @var{obj} is a service.
33741 @deffn {Scheme Procedure} service-kind @var{service}
33742 Return the type of @var{service}---i.e., a @code{<service-type>} object.
33745 @deffn {Scheme Procedure} service-value @var{service}
33746 Return the value associated with @var{service}. It represents its
33750 Here is an example of how a service is created and manipulated:
33754 (service nginx-service-type
33755 (nginx-configuration
33757 (log-directory log-directory)
33758 (run-directory run-directory)
33759 (file config-file))))
33764 (eq? (service-kind s) nginx-service-type)
33768 The @code{modify-services} form provides a handy way to change the
33769 parameters of some of the services of a list such as
33770 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
33771 evaluates to a list of services. Of course, you could always use
33772 standard list combinators such as @code{map} and @code{fold} to do that
33773 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
33774 @code{modify-services} simply provides a more concise form for this
33777 @deffn {Scheme Syntax} modify-services @var{services} @
33778 (@var{type} @var{variable} => @var{body}) @dots{}
33780 Modify the services listed in @var{services} according to the given
33781 clauses. Each clause has the form:
33784 (@var{type} @var{variable} => @var{body})
33787 where @var{type} is a service type---e.g.,
33788 @code{guix-service-type}---and @var{variable} is an identifier that is
33789 bound within the @var{body} to the service parameters---e.g., a
33790 @code{guix-configuration} instance---of the original service of that
33793 The @var{body} should evaluate to the new service parameters, which will
33794 be used to configure the new service. This new service will replace the
33795 original in the resulting list. Because a service's service parameters
33796 are created using @code{define-record-type*}, you can write a succinct
33797 @var{body} that evaluates to the new service parameters by using the
33798 @code{inherit} feature that @code{define-record-type*} provides.
33800 @xref{Using the Configuration System}, for example usage.
33804 Next comes the programming interface for service types. This is
33805 something you want to know when writing new service definitions, but not
33806 necessarily when simply looking for ways to customize your
33807 @code{operating-system} declaration.
33809 @deftp {Data Type} service-type
33810 @cindex service type
33811 This is the representation of a @dfn{service type} (@pxref{Service Types
33816 This is a symbol, used only to simplify inspection and debugging.
33818 @item @code{extensions}
33819 A non-empty list of @code{<service-extension>} objects (see below).
33821 @item @code{compose} (default: @code{#f})
33822 If this is @code{#f}, then the service type denotes services that cannot
33823 be extended---i.e., services that do not receive ``values'' from other
33826 Otherwise, it must be a one-argument procedure. The procedure is called
33827 by @code{fold-services} and is passed a list of values collected from
33828 extensions. It may return any single value.
33830 @item @code{extend} (default: @code{#f})
33831 If this is @code{#f}, services of this type cannot be extended.
33833 Otherwise, it must be a two-argument procedure: @code{fold-services}
33834 calls it, passing it the initial value of the service as the first
33835 argument and the result of applying @code{compose} to the extension
33836 values as the second argument. It must return a value that is a valid
33837 parameter value for the service instance.
33839 @item @code{description}
33840 This is a string, possibly using Texinfo markup, describing in a couple
33841 of sentences what the service is about. This string allows users to
33842 find about the service through @command{guix system search}
33843 (@pxref{Invoking guix system}).
33845 @item @code{default-value} (default: @code{&no-default-value})
33846 The default value associated for instances of this service type. This
33847 allows users to use the @code{service} form without its second argument:
33850 (service @var{type})
33853 The returned service in this case has the default value specified by
33857 @xref{Service Types and Services}, for examples.
33860 @deffn {Scheme Procedure} service-extension @var{target-type} @
33862 Return a new extension for services of type @var{target-type}.
33863 @var{compute} must be a one-argument procedure: @code{fold-services}
33864 calls it, passing it the value associated with the service that provides
33865 the extension; it must return a valid value for the target service.
33868 @deffn {Scheme Procedure} service-extension? @var{obj}
33869 Return true if @var{obj} is a service extension.
33872 Occasionally, you might want to simply extend an existing service. This
33873 involves creating a new service type and specifying the extension of
33874 interest, which can be verbose; the @code{simple-service} procedure
33875 provides a shorthand for this.
33877 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
33878 Return a service that extends @var{target} with @var{value}. This works
33879 by creating a singleton service type @var{name}, of which the returned
33880 service is an instance.
33882 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
33886 (simple-service 'my-mcron-job mcron-service-type
33887 #~(job '(next-hour (3)) "guix gc -F 2G"))
33891 At the core of the service abstraction lies the @code{fold-services}
33892 procedure, which is responsible for ``compiling'' a list of services
33893 down to a single directory that contains everything needed to boot and
33894 run the system---the directory shown by the @command{guix system build}
33895 command (@pxref{Invoking guix system}). In essence, it propagates
33896 service extensions down the service graph, updating each node parameters
33897 on the way, until it reaches the root node.
33899 @deffn {Scheme Procedure} fold-services @var{services} @
33900 [#:target-type @var{system-service-type}]
33901 Fold @var{services} by propagating their extensions down to the root of
33902 type @var{target-type}; return the root service adjusted accordingly.
33905 Lastly, the @code{(gnu services)} module also defines several essential
33906 service types, some of which are listed below.
33908 @defvr {Scheme Variable} system-service-type
33909 This is the root of the service graph. It produces the system directory
33910 as returned by the @command{guix system build} command.
33913 @defvr {Scheme Variable} boot-service-type
33914 The type of the ``boot service'', which produces the @dfn{boot script}.
33915 The boot script is what the initial RAM disk runs when booting.
33918 @defvr {Scheme Variable} etc-service-type
33919 The type of the @file{/etc} service. This service is used to create
33920 files under @file{/etc} and can be extended by
33921 passing it name/file tuples such as:
33924 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
33927 In this example, the effect would be to add an @file{/etc/issue} file
33928 pointing to the given file.
33931 @defvr {Scheme Variable} setuid-program-service-type
33932 Type for the ``setuid-program service''. This service collects lists of
33933 executable file names, passed as gexps, and adds them to the set of
33934 setuid-root programs on the system (@pxref{Setuid Programs}).
33937 @defvr {Scheme Variable} profile-service-type
33938 Type of the service that populates the @dfn{system profile}---i.e., the
33939 programs under @file{/run/current-system/profile}. Other services can
33940 extend it by passing it lists of packages to add to the system profile.
33943 @cindex provenance tracking, of the operating system
33944 @anchor{provenance-service-type}
33945 @defvr {Scheme Variable} provenance-service-type
33946 This is the type of the service that records @dfn{provenance meta-data}
33947 in the system itself. It creates several files under
33948 @file{/run/current-system}:
33952 This is a ``channel file'' that can be passed to @command{guix pull -C}
33953 or @command{guix time-machine -C}, and which describes the channels used
33954 to build the system, if that information was available
33955 (@pxref{Channels}).
33957 @item configuration.scm
33958 This is the file that was passed as the value for this
33959 @code{provenance-service-type} service. By default, @command{guix
33960 system reconfigure} automatically passes the OS configuration file it
33961 received on the command line.
33964 This contains the same information as the two other files but in a
33965 format that is more readily processable.
33968 In general, these two pieces of information (channels and configuration
33969 file) are enough to reproduce the operating system ``from source''.
33972 This information is necessary to rebuild your operating system, but it
33973 is not always sufficient. In particular, @file{configuration.scm}
33974 itself is insufficient if it is not self-contained---if it refers to
33975 external Guile modules or to extra files. If you want
33976 @file{configuration.scm} to be self-contained, we recommend that modules
33977 or files it refers to be part of a channel.
33979 Besides, provenance meta-data is ``silent'' in the sense that it does
33980 not change the bits contained in your system, @emph{except for the
33981 meta-data bits themselves}. Two different OS configurations or sets of
33982 channels can lead to the same system, bit-for-bit; when
33983 @code{provenance-service-type} is used, these two systems will have
33984 different meta-data and thus different store file names, which makes
33985 comparison less trivial.
33988 This service is automatically added to your operating system
33989 configuration when you use @command{guix system reconfigure},
33990 @command{guix system init}, or @command{guix deploy}.
33993 @node Shepherd Services
33994 @subsection Shepherd Services
33996 @cindex shepherd services
33998 @cindex init system
33999 The @code{(gnu services shepherd)} module provides a way to define
34000 services managed by the GNU@tie{}Shepherd, which is the
34001 initialization system---the first process that is started when the
34002 system boots, also known as PID@tie{}1
34003 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
34005 Services in the Shepherd can depend on each other. For instance, the
34006 SSH daemon may need to be started after the syslog daemon has been
34007 started, which in turn can only happen once all the file systems have
34008 been mounted. The simple operating system defined earlier (@pxref{Using
34009 the Configuration System}) results in a service graph like this:
34011 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
34013 You can actually generate such a graph for any operating system
34014 definition using the @command{guix system shepherd-graph} command
34015 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
34017 The @code{%shepherd-root-service} is a service object representing
34018 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
34019 by passing it lists of @code{<shepherd-service>} objects.
34021 @deftp {Data Type} shepherd-service
34022 The data type representing a service managed by the Shepherd.
34025 @item @code{provision}
34026 This is a list of symbols denoting what the service provides.
34028 These are the names that may be passed to @command{herd start},
34029 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
34030 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
34031 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
34033 @item @code{requirement} (default: @code{'()})
34034 List of symbols denoting the Shepherd services this one depends on.
34036 @cindex one-shot services, for the Shepherd
34037 @item @code{one-shot?} (default: @code{#f})
34038 Whether this service is @dfn{one-shot}. One-shot services stop immediately
34039 after their @code{start} action has completed. @xref{Slots of services,,,
34040 shepherd, The GNU Shepherd Manual}, for more info.
34042 @item @code{respawn?} (default: @code{#t})
34043 Whether to restart the service when it stops, for instance when the
34044 underlying process dies.
34047 @itemx @code{stop} (default: @code{#~(const #f)})
34048 The @code{start} and @code{stop} fields refer to the Shepherd's
34049 facilities to start and stop processes (@pxref{Service De- and
34050 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
34051 G-expressions that get expanded in the Shepherd configuration file
34052 (@pxref{G-Expressions}).
34054 @item @code{actions} (default: @code{'()})
34055 @cindex actions, of Shepherd services
34056 This is a list of @code{shepherd-action} objects (see below) defining
34057 @dfn{actions} supported by the service, in addition to the standard
34058 @code{start} and @code{stop} actions. Actions listed here become available as
34059 @command{herd} sub-commands:
34062 herd @var{action} @var{service} [@var{arguments}@dots{}]
34065 @item @code{auto-start?} (default: @code{#t})
34066 Whether this service should be started automatically by the Shepherd. If it
34067 is @code{#f} the service has to be started manually with @code{herd start}.
34069 @item @code{documentation}
34070 A documentation string, as shown when running:
34073 herd doc @var{service-name}
34076 where @var{service-name} is one of the symbols in @code{provision}
34077 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
34079 @item @code{modules} (default: @code{%default-modules})
34080 This is the list of modules that must be in scope when @code{start} and
34081 @code{stop} are evaluated.
34086 The example below defines a Shepherd service that spawns
34087 @command{syslogd}, the system logger from the GNU Networking Utilities
34088 (@pxref{syslogd invocation, @command{syslogd},, inetutils, GNU
34092 (let ((config (plain-file "syslogd.conf" "@dots{}")))
34094 (documentation "Run the syslog daemon (syslogd).")
34095 (provision '(syslogd))
34096 (requirement '(user-processes))
34097 (start #~(make-forkexec-constructor
34098 (list #$(file-append inetutils "/libexec/syslogd")
34099 "--rcfile" #$config)
34100 #:pid-file "/var/run/syslog.pid"))
34101 (stop #~(make-kill-destructor))))
34104 Key elements in this example are the @code{start} and @code{stop}
34105 fields: they are @dfn{staged} code snippets that use the
34106 @code{make-forkexec-constructor} procedure provided by the Shepherd and
34107 its dual, @code{make-kill-destructor} (@pxref{Service De- and
34108 Constructors,,, shepherd, The GNU Shepherd Manual}). The @code{start}
34109 field will have @command{shepherd} spawn @command{syslogd} with the
34110 given option; note that we pass @code{config} after @option{--rcfile},
34111 which is a configuration file declared above (contents of this file are
34112 omitted). Likewise, the @code{stop} field tells how this service is to
34113 be stopped; in this case, it is stopped by making the @code{kill} system
34114 call on its PID@. Code staging is achieved using G-expressions:
34115 @code{#~} stages code, while @code{#$} ``escapes'' back to host code
34116 (@pxref{G-Expressions}).
34118 @deftp {Data Type} shepherd-action
34119 This is the data type that defines additional actions implemented by a
34120 Shepherd service (see above).
34124 Symbol naming the action.
34126 @item documentation
34127 This is a documentation string for the action. It can be viewed by running:
34130 herd doc @var{service} action @var{action}
34134 This should be a gexp that evaluates to a procedure of at least one argument,
34135 which is the ``running value'' of the service (@pxref{Slots of services,,,
34136 shepherd, The GNU Shepherd Manual}).
34139 The following example defines an action called @code{say-hello} that kindly
34145 (documentation "Say hi!")
34146 (procedure #~(lambda (running . args)
34147 (format #t "Hello, friend! arguments: ~s\n"
34152 Assuming this action is added to the @code{example} service, then you can do:
34155 # herd say-hello example
34156 Hello, friend! arguments: ()
34157 # herd say-hello example a b c
34158 Hello, friend! arguments: ("a" "b" "c")
34161 This, as you can see, is a fairly sophisticated way to say hello.
34162 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
34166 @defvr {Scheme Variable} shepherd-root-service-type
34167 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
34169 This is the service type that extensions target when they want to create
34170 shepherd services (@pxref{Service Types and Services}, for an example).
34171 Each extension must pass a list of @code{<shepherd-service>}. Its
34172 value must be a @code{shepherd-configuration}, as described below.
34175 @deftp {Data Type} shepherd-configuration
34176 This data type represents the Shepherd's configuration.
34179 @item shepherd (default: @code{shepherd})
34180 The Shepherd package to use.
34182 @item services (default: @code{'()})
34183 A list of @code{<shepherd-service>} to start.
34184 You should probably use the service extension
34185 mechanism instead (@pxref{Shepherd Services}).
34189 The following example specifies the Shepherd package for the operating
34195 (services (append (list openssh-service-type))
34199 ;; Use own Shepherd package.
34200 (essential-services
34201 (modify-services (operating-system-default-essential-services
34202 this-operating-system)
34203 (shepherd-root-service-type config => (shepherd-configuration
34205 (shepherd my-shepherd))))))
34208 @defvr {Scheme Variable} %shepherd-root-service
34209 This service represents PID@tie{}1.
34213 @node Documentation
34214 @chapter Documentation
34216 @cindex documentation, searching for
34217 @cindex searching for documentation
34218 @cindex Info, documentation format
34220 @cindex manual pages
34221 In most cases packages installed with Guix come with documentation.
34222 There are two main documentation formats: ``Info'', a browseable
34223 hypertext format used for GNU software, and ``manual pages'' (or ``man
34224 pages''), the linear documentation format traditionally found on Unix.
34225 Info manuals are accessed with the @command{info} command or with Emacs,
34226 and man pages are accessed using @command{man}.
34228 You can look for documentation of software installed on your system by
34229 keyword. For example, the following command searches for information
34230 about ``TLS'' in Info manuals:
34234 "(emacs)Network Security" -- STARTTLS
34235 "(emacs)Network Security" -- TLS
34236 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
34237 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
34242 The command below searches for the same keyword in man pages:
34246 SSL (7) - OpenSSL SSL/TLS library
34247 certtool (1) - GnuTLS certificate tool
34251 These searches are purely local to your computer so you have the
34252 guarantee that documentation you find corresponds to what you have
34253 actually installed, you can access it off-line, and your privacy is
34256 Once you have these results, you can view the relevant documentation by
34260 $ info "(gnutls)Core TLS API"
34270 Info manuals contain sections and indices as well as hyperlinks like
34271 those found in Web pages. The @command{info} reader (@pxref{Top, Info
34272 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
34273 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
34274 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
34275 Introduction}, for an introduction to Info navigation.
34277 @node Installing Debugging Files
34278 @chapter Installing Debugging Files
34280 @cindex debugging files
34281 Program binaries, as produced by the GCC compilers for instance, are
34282 typically written in the ELF format, with a section containing
34283 @dfn{debugging information}. Debugging information is what allows the
34284 debugger, GDB, to map binary code to source code; it is required to
34285 debug a compiled program in good conditions.
34287 This chapter explains how to use separate debug info when packages
34288 provide it, and how to rebuild packages with debug info when it's
34292 * Separate Debug Info:: Installing 'debug' outputs.
34293 * Rebuilding Debug Info:: Building missing debug info.
34296 @node Separate Debug Info
34297 @section Separate Debug Info
34299 The problem with debugging information is that is takes up a fair amount
34300 of disk space. For example, debugging information for the GNU C Library
34301 weighs in at more than 60 MiB@. Thus, as a user, keeping all the
34302 debugging info of all the installed programs is usually not an option.
34303 Yet, space savings should not come at the cost of an impediment to
34304 debugging---especially in the GNU system, which should make it easier
34305 for users to exert their computing freedom (@pxref{GNU Distribution}).
34307 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
34308 mechanism that allows users to get the best of both worlds: debugging
34309 information can be stripped from the binaries and stored in separate
34310 files. GDB is then able to load debugging information from those files,
34311 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
34314 The GNU distribution takes advantage of this by storing debugging
34315 information in the @code{lib/debug} sub-directory of a separate package
34316 output unimaginatively called @code{debug} (@pxref{Packages with
34317 Multiple Outputs}). Users can choose to install the @code{debug} output
34318 of a package when they need it. For instance, the following command
34319 installs the debugging information for the GNU C Library and for GNU
34323 guix install glibc:debug guile:debug
34326 GDB must then be told to look for debug files in the user's profile, by
34327 setting the @code{debug-file-directory} variable (consider setting it
34328 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
34332 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
34335 From there on, GDB will pick up debugging information from the
34336 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
34338 In addition, you will most likely want GDB to be able to show the source
34339 code being debugged. To do that, you will have to unpack the source
34340 code of the package of interest (obtained with @code{guix build
34341 --source}, @pxref{Invoking guix build}), and to point GDB to that source
34342 directory using the @code{directory} command (@pxref{Source Path,
34343 @code{directory},, gdb, Debugging with GDB}).
34345 @c XXX: keep me up-to-date
34346 The @code{debug} output mechanism in Guix is implemented by the
34347 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
34348 opt-in---debugging information is available only for the packages with
34349 definitions explicitly declaring a @code{debug} output. To check
34350 whether a package has a @code{debug} output, use @command{guix package
34351 --list-available} (@pxref{Invoking guix package}).
34353 Read on for how to deal with packages lacking a @code{debug} output.
34355 @node Rebuilding Debug Info
34356 @section Rebuilding Debug Info
34358 @cindex debugging info, rebuilding
34359 As we saw above, some packages, but not all, provide debugging info in a
34360 @code{debug} output. What can you do when debugging info is missing?
34361 The @option{--with-debug-info} option provides a solution to that: it
34362 allows you to rebuild the package(s) for which debugging info is
34363 missing---and only those---and to graft those onto the application
34364 you're debugging. Thus, while it's not as fast as installing a
34365 @code{debug} output, it is relatively inexpensive.
34367 Let's illustrate that. Suppose you're experiencing a bug in Inkscape
34368 and would like to see what's going on in GLib, a library that's deep
34369 down in its dependency graph. As it turns out, GLib does not have a
34370 @code{debug} output and the backtrace GDB shows is all sadness:
34374 #0 0x00007ffff5f92190 in g_getenv ()
34375 from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
34376 #1 0x00007ffff608a7d6 in gobject_init_ctor ()
34377 from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
34378 #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
34379 env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
34380 #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
34384 To address that, you install Inkscape linked against a variant GLib that
34385 contains debug info:
34388 guix install inkscape --with-debug-info=glib
34391 This time, debugging will be a whole lot nicer:
34394 $ gdb --args sh -c 'exec inkscape'
34397 Function "g_getenv" not defined.
34398 Make breakpoint pending on future shared library load? (y or [n]) y
34399 Breakpoint 1 (g_getenv) pending.
34401 Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
34404 #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
34405 #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
34406 #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
34407 #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
34408 env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
34414 Note that there can be packages for which @option{--with-debug-info}
34415 will not have the desired effect. @xref{Package Transformation Options,
34416 @option{--with-debug-info}}, for more information.
34418 @node Security Updates
34419 @chapter Security Updates
34421 @cindex security updates
34422 @cindex security vulnerabilities
34423 Occasionally, important security vulnerabilities are discovered in software
34424 packages and must be patched. Guix developers try hard to keep track of
34425 known vulnerabilities and to apply fixes as soon as possible in the
34426 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
34427 containing only security updates). The @command{guix lint} tool helps
34428 developers find out about vulnerable versions of software packages in the
34433 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
34434 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
34435 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
34439 @xref{Invoking guix lint}, for more information.
34441 Guix follows a functional
34442 package management discipline (@pxref{Introduction}), which implies
34443 that, when a package is changed, @emph{every package that depends on it}
34444 must be rebuilt. This can significantly slow down the deployment of
34445 fixes in core packages such as libc or Bash, since basically the whole
34446 distribution would need to be rebuilt. Using pre-built binaries helps
34447 (@pxref{Substitutes}), but deployment may still take more time than
34451 To address this, Guix implements @dfn{grafts}, a mechanism that allows
34452 for fast deployment of critical updates without the costs associated
34453 with a whole-distribution rebuild. The idea is to rebuild only the
34454 package that needs to be patched, and then to ``graft'' it onto packages
34455 explicitly installed by the user and that were previously referring to
34456 the original package. The cost of grafting is typically very low, and
34457 order of magnitudes lower than a full rebuild of the dependency chain.
34459 @cindex replacements of packages, for grafts
34460 For instance, suppose a security update needs to be applied to Bash.
34461 Guix developers will provide a package definition for the ``fixed''
34462 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
34463 Packages}). Then, the original package definition is augmented with a
34464 @code{replacement} field pointing to the package containing the bug fix:
34471 (replacement bash-fixed)))
34474 From there on, any package depending directly or indirectly on Bash---as
34475 reported by @command{guix gc --requisites} (@pxref{Invoking guix
34476 gc})---that is installed is automatically ``rewritten'' to refer to
34477 @code{bash-fixed} instead of @code{bash}. This grafting process takes
34478 time proportional to the size of the package, usually less than a
34479 minute for an ``average'' package on a recent machine. Grafting is
34480 recursive: when an indirect dependency requires grafting, then grafting
34481 ``propagates'' up to the package that the user is installing.
34483 Currently, the length of the name and version of the graft and that of
34484 the package it replaces (@code{bash-fixed} and @code{bash} in the example
34485 above) must be equal. This restriction mostly comes from the fact that
34486 grafting works by patching files, including binary files, directly.
34487 Other restrictions may apply: for instance, when adding a graft to a
34488 package providing a shared library, the original shared library and its
34489 replacement must have the same @code{SONAME} and be binary-compatible.
34491 The @option{--no-grafts} command-line option allows you to forcefully
34492 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
34496 guix build bash --no-grafts
34500 returns the store file name of the original Bash, whereas:
34507 returns the store file name of the ``fixed'', replacement Bash. This
34508 allows you to distinguish between the two variants of Bash.
34510 To verify which Bash your whole profile refers to, you can run
34511 (@pxref{Invoking guix gc}):
34514 guix gc -R $(readlink -f ~/.guix-profile) | grep bash
34518 @dots{} and compare the store file names that you get with those above.
34519 Likewise for a complete Guix system generation:
34522 guix gc -R $(guix system build my-config.scm) | grep bash
34525 Lastly, to check which Bash running processes are using, you can use the
34526 @command{lsof} command:
34529 lsof | grep /gnu/store/.*bash
34533 @node Bootstrapping
34534 @chapter Bootstrapping
34536 @c Adapted from the ELS 2013 paper.
34538 @cindex bootstrapping
34540 Bootstrapping in our context refers to how the distribution gets built
34541 ``from nothing''. Remember that the build environment of a derivation
34542 contains nothing but its declared inputs (@pxref{Introduction}). So
34543 there's an obvious chicken-and-egg problem: how does the first package
34544 get built? How does the first compiler get compiled?
34546 It is tempting to think of this question as one that only die-hard
34547 hackers may care about. However, while the answer to that question is
34548 technical in nature, its implications are wide-ranging. How the
34549 distribution is bootstrapped defines the extent to which we, as
34550 individuals and as a collective of users and hackers, can trust the
34551 software we run. It is a central concern from the standpoint of
34552 @emph{security} and from a @emph{user freedom} viewpoint.
34554 @cindex bootstrap binaries
34555 The GNU system is primarily made of C code, with libc at its core. The
34556 GNU build system itself assumes the availability of a Bourne shell and
34557 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
34558 `grep'. Furthermore, build programs---programs that run
34559 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
34560 (@pxref{Derivations}). Consequently, to be able to build anything at
34561 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
34562 Binutils, libc, and the other packages mentioned above---the
34563 @dfn{bootstrap binaries}.
34565 These bootstrap binaries are ``taken for granted'', though we can also
34566 re-create them if needed (@pxref{Preparing to Use the Bootstrap
34570 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
34571 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
34574 @node Reduced Binary Seed Bootstrap
34575 @section The Reduced Binary Seed Bootstrap
34577 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
34578 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
34579 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
34580 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
34581 ``taken for granted.''
34583 Taking the bootstrap binaries for granted means that we consider them to
34584 be a correct and trustworthy ``seed'' for building the complete system.
34585 Therein lies a problem: the combined size of these bootstrap binaries is
34586 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
34587 or even inspecting these is next to impossible.
34589 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
34590 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
34591 Source Bootstrap'' and while we are working towards that goal it would
34592 be hyperbole to use that term for what we do now.}.
34594 The Reduced Binary Seed bootstrap removes the most critical tools---from a
34595 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
34596 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
34597 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
34598 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
34600 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
34601 C Library are built from source. From here on the more traditional
34602 bootstrap process resumes. This approach has reduced the bootstrap
34603 binaries in size to about 145MB in Guix v1.1.
34605 The next step that Guix has taken is to replace the shell and all its
34606 utilities with implementations in Guile Scheme, the @emph{Scheme-only
34607 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
34608 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
34609 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
34610 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
34611 removed are now built from source.
34613 Building the GNU System from source is currently only possible by adding
34614 some historical GNU packages as intermediate steps@footnote{Packages
34615 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
34616 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
34617 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
34618 and GNU packages become more bootstrappable again (e.g., new releases of
34619 GNU Sed will also ship as gzipped tarballs again, as alternative to the
34620 hard to bootstrap @code{xz}-compression), this set of added packages can
34621 hopefully be reduced again.
34623 The graph below shows the resulting dependency graph for
34624 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
34625 traditional bootstrap of the rest of the Guix System.
34627 @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
34628 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
34630 The only significant binary bootstrap seeds that remain@footnote{
34631 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
34632 together with @code{mes}.} are a Scheme intepreter and a Scheme
34633 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
34634 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
34635 to get Guile running.}.
34637 This further reduction has brought down the size of the binary seed to
34638 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
34640 Work is ongoing to remove all binary blobs from our free software
34641 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
34642 is work to bring these bootstraps to the @code{arm-linux} and
34643 @code{aarch64-linux} architectures and to the Hurd.
34645 If you are interested, join us on @samp{#bootstrappable} on the Freenode
34646 IRC network or discuss on @email{bug-mes@@gnu.org} or
34647 @email{gash-devel@@nongnu.org}.
34649 @node Preparing to Use the Bootstrap Binaries
34650 @section Preparing to Use the Bootstrap Binaries
34652 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
34653 @c large image, it's hard to scroll. Oh well.
34654 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
34656 The figure above shows the very beginning of the dependency graph of the
34657 distribution, corresponding to the package definitions of the @code{(gnu
34658 packages bootstrap)} module. A similar figure can be generated with
34659 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
34662 guix graph -t derivation \
34663 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
34664 | dot -Tps > gcc.ps
34667 or, for the further Reduced Binary Seed bootstrap
34670 guix graph -t derivation \
34671 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
34672 | dot -Tps > mes.ps
34675 At this level of detail, things are
34676 slightly complex. First, Guile itself consists of an ELF executable,
34677 along with many source and compiled Scheme files that are dynamically
34678 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
34679 tarball shown in this graph. This tarball is part of Guix's ``source''
34680 distribution, and gets inserted into the store with @code{add-to-store}
34681 (@pxref{The Store}).
34683 But how do we write a derivation that unpacks this tarball and adds it
34684 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
34685 derivation---the first one that gets built---uses @code{bash} as its
34686 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
34687 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
34688 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
34689 the Guix source distribution, whose sole purpose is to allow the Guile
34690 tarball to be unpacked.
34692 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
34693 Guile that can be used to run subsequent build programs. Its first task
34694 is to download tarballs containing the other pre-built binaries---this
34695 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
34696 @code{ftp-client.scm} are used for this purpose. The
34697 @code{module-import.drv} derivations import those modules in a directory
34698 in the store, using the original layout. The
34699 @code{module-import-compiled.drv} derivations compile those modules, and
34700 write them in an output directory with the right layout. This
34701 corresponds to the @code{#:modules} argument of
34702 @code{build-expression->derivation} (@pxref{Derivations}).
34704 Finally, the various tarballs are unpacked by the derivations
34705 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
34706 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
34707 point we have a working C tool chain.
34709 @unnumberedsec Building the Build Tools
34711 Bootstrapping is complete when we have a full tool chain that does not
34712 depend on the pre-built bootstrap tools discussed above. This
34713 no-dependency requirement is verified by checking whether the files of
34714 the final tool chain contain references to the @file{/gnu/store}
34715 directories of the bootstrap inputs. The process that leads to this
34716 ``final'' tool chain is described by the package definitions found in
34717 the @code{(gnu packages commencement)} module.
34719 The @command{guix graph} command allows us to ``zoom out'' compared to
34720 the graph above, by looking at the level of package objects instead of
34721 individual derivations---remember that a package may translate to
34722 several derivations, typically one derivation to download its source,
34723 one to build the Guile modules it needs, and one to actually build the
34724 package from source. The command:
34727 guix graph -t bag \
34728 -e '(@@@@ (gnu packages commencement)
34729 glibc-final-with-bootstrap-bash)' | xdot -
34733 displays the dependency graph leading to the ``final'' C
34734 library@footnote{You may notice the @code{glibc-intermediate} label,
34735 suggesting that it is not @emph{quite} final, but as a good
34736 approximation, we will consider it final.}, depicted below.
34738 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
34740 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
34741 The first tool that gets built with the bootstrap binaries is
34742 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
34743 for all the following packages. From there Findutils and Diffutils get
34746 Then come the first-stage Binutils and GCC, built as pseudo cross
34747 tools---i.e., with @option{--target} equal to @option{--host}. They are
34748 used to build libc. Thanks to this cross-build trick, this libc is
34749 guaranteed not to hold any reference to the initial tool chain.
34751 From there the final Binutils and GCC (not shown above) are built. GCC
34752 uses @command{ld} from the final Binutils, and links programs against
34753 the just-built libc. This tool chain is used to build the other
34754 packages used by Guix and by the GNU Build System: Guile, Bash,
34757 And voilà! At this point we have the complete set of build tools that
34758 the GNU Build System expects. These are in the @code{%final-inputs}
34759 variable of the @code{(gnu packages commencement)} module, and are
34760 implicitly used by any package that uses @code{gnu-build-system}
34761 (@pxref{Build Systems, @code{gnu-build-system}}).
34764 @unnumberedsec Building the Bootstrap Binaries
34766 @cindex bootstrap binaries
34767 Because the final tool chain does not depend on the bootstrap binaries,
34768 those rarely need to be updated. Nevertheless, it is useful to have an
34769 automated way to produce them, should an update occur, and this is what
34770 the @code{(gnu packages make-bootstrap)} module provides.
34772 The following command builds the tarballs containing the bootstrap binaries
34773 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
34774 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
34775 and Guile, and a tarball containing a mixture of Coreutils and other basic
34776 command-line tools):
34779 guix build bootstrap-tarballs
34782 The generated tarballs are those that should be referred to in the
34783 @code{(gnu packages bootstrap)} module mentioned at the beginning of
34786 Still here? Then perhaps by now you've started to wonder: when do we
34787 reach a fixed point? That is an interesting question! The answer is
34788 unknown, but if you would like to investigate further (and have
34789 significant computational and storage resources to do so), then let us
34792 @unnumberedsec Reducing the Set of Bootstrap Binaries
34794 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
34795 binary code! Why is that a problem? It's a problem because these big chunks
34796 of binary code are practically non-auditable, which makes it hard to establish
34797 what source code produced them. Every unauditable binary also leaves us
34798 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
34799 paper @emph{Reflections on Trusting Trust}.
34801 This is mitigated by the fact that our bootstrap binaries were generated
34802 from an earlier Guix revision. Nevertheless it lacks the level of
34803 transparency that we get in the rest of the package dependency graph,
34804 where Guix always gives us a source-to-binary mapping. Thus, our goal
34805 is to reduce the set of bootstrap binaries to the bare minimum.
34807 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
34808 on-going projects to do that. One of these is about replacing the
34809 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
34810 of increasing complexity, which could be built from source starting from
34811 a simple and auditable assembler.
34813 Our first major achievement is the replacement of of GCC, the GNU C Library
34814 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
34815 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
34816 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
34817 bootstrapped yet and thus we inject them as binary seeds. We call this the
34818 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
34819 binaries! Also, it has eliminated the C compiler binary; i686-linux and
34820 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
34822 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
34823 also looking at any other bootstrap binaries. Your help is welcome!
34826 @chapter Porting to a New Platform
34828 As discussed above, the GNU distribution is self-contained, and
34829 self-containment is achieved by relying on pre-built ``bootstrap
34830 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
34831 operating system kernel, CPU architecture, and application binary
34832 interface (ABI). Thus, to port the distribution to a platform that is
34833 not yet supported, one must build those bootstrap binaries, and update
34834 the @code{(gnu packages bootstrap)} module to use them on that platform.
34836 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
34837 When everything goes well, and assuming the GNU tool chain supports the
34838 target platform, this can be as simple as running a command like this
34842 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
34845 For this to work, the @code{glibc-dynamic-linker} procedure in
34846 @code{(gnu packages bootstrap)} must be augmented to return the right
34847 file name for libc's dynamic linker on that platform; likewise,
34848 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
34849 taught about the new platform.
34851 Once these are built, the @code{(gnu packages bootstrap)} module needs
34852 to be updated to refer to these binaries on the target platform. That
34853 is, the hashes and URLs of the bootstrap tarballs for the new platform
34854 must be added alongside those of the currently supported platforms. The
34855 bootstrap Guile tarball is treated specially: it is expected to be
34856 available locally, and @file{gnu/local.mk} has rules to download it for
34857 the supported architectures; a rule for the new platform must be added
34860 In practice, there may be some complications. First, it may be that the
34861 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
34862 above) is not recognized by all the GNU tools. Typically, glibc
34863 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
34864 configure flag (see @code{gcc.scm} for examples of how to handle this).
34865 Second, some of the required packages could fail to build for that
34866 platform. Lastly, the generated binaries could be broken for some
34869 @c *********************************************************************
34870 @include contributing.texi
34872 @c *********************************************************************
34873 @node Acknowledgments
34874 @chapter Acknowledgments
34876 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
34877 which was designed and
34878 implemented by Eelco Dolstra, with contributions from other people (see
34879 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
34880 management, and promoted unprecedented features, such as transactional
34881 package upgrades and rollbacks, per-user profiles, and referentially
34882 transparent build processes. Without this work, Guix would not exist.
34884 The Nix-based software distributions, Nixpkgs and NixOS, have also been
34885 an inspiration for Guix.
34887 GNU@tie{}Guix itself is a collective work with contributions from a
34888 number of people. See the @file{AUTHORS} file in Guix for more
34889 information on these fine people. The @file{THANKS} file lists people
34890 who have helped by reporting bugs, taking care of the infrastructure,
34891 providing artwork and themes, making suggestions, and more---thank you!
34894 @c *********************************************************************
34895 @node GNU Free Documentation License
34896 @appendix GNU Free Documentation License
34897 @cindex license, GNU Free Documentation License
34898 @include fdl-1.3.texi
34900 @c *********************************************************************
34901 @node Concept Index
34902 @unnumbered Concept Index
34905 @node Programming Index
34906 @unnumbered Programming Index
34907 @syncodeindex tp fn
34908 @syncodeindex vr fn
34913 @c Local Variables:
34914 @c ispell-local-dictionary: "american";