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 GNOME packages;
11719 the updater for KDE packages;
11721 the updater for X.org packages;
11723 the updater for packages hosted on kernel.org;
11725 the updater for @uref{https://elpa.gnu.org/, ELPA} packages;
11727 the updater for @uref{https://cran.r-project.org/, CRAN} packages;
11729 the updater for @uref{https://www.bioconductor.org/, Bioconductor} R packages;
11731 the updater for @uref{https://www.cpan.org/, CPAN} packages;
11733 the updater for @uref{https://pypi.python.org, PyPI} packages.
11735 the updater for @uref{https://rubygems.org, RubyGems} packages.
11737 the updater for @uref{https://github.com, GitHub} packages.
11739 the updater for @uref{https://hackage.haskell.org, Hackage} packages.
11741 the updater for @uref{https://www.stackage.org, Stackage} packages.
11743 the updater for @uref{https://crates.io, Crates} packages.
11745 the updater for @uref{https://launchpad.net, Launchpad} packages.
11747 a generic updater that crawls the HTML page where the source tarball of
11748 the package is hosted, when applicable.
11751 For instance, the following command only checks for updates of Emacs
11752 packages hosted at @code{elpa.gnu.org} and for updates of CRAN packages:
11755 $ guix refresh --type=elpa,cran
11756 gnu/packages/statistics.scm:819:13: r-testthat would be upgraded from 0.10.0 to 0.11.0
11757 gnu/packages/emacs.scm:856:13: emacs-auctex would be upgraded from 11.88.6 to 11.88.9
11760 @item --list-updaters
11762 List available updaters and exit (see @option{--type} above).
11764 For each updater, display the fraction of packages it covers; at the
11765 end, display the fraction of packages covered by all these updaters.
11768 In addition, @command{guix refresh} can be passed one or more package
11769 names, as in this example:
11772 $ ./pre-inst-env guix refresh -u emacs idutils gcc@@4.8
11776 The command above specifically updates the @code{emacs} and
11777 @code{idutils} packages. The @option{--select} option would have no
11778 effect in this case. You might also want to update definitions that
11779 correspond to the packages installed in your profile:
11782 $ ./pre-inst-env guix refresh -u \
11783 $(guix package --list-installed | cut -f1)
11786 When considering whether to upgrade a package, it is sometimes
11787 convenient to know which packages would be affected by the upgrade and
11788 should be checked for compatibility. For this the following option may
11789 be used when passing @command{guix refresh} one or more package names:
11793 @item --list-dependent
11795 List top-level dependent packages that would need to be rebuilt as a
11796 result of upgrading one or more packages.
11798 @xref{Invoking guix graph, the @code{reverse-package} type of
11799 @command{guix graph}}, for information on how to visualize the list of
11800 dependents of a package.
11804 Be aware that the @option{--list-dependent} option only
11805 @emph{approximates} the rebuilds that would be required as a result of
11806 an upgrade. More rebuilds might be required under some circumstances.
11809 $ guix refresh --list-dependent flex
11810 Building the following 120 packages would ensure 213 dependent packages are rebuilt:
11811 hop@@2.4.0 geiser@@0.4 notmuch@@0.18 mu@@0.9.9.5 cflow@@1.4 idutils@@4.6 @dots{}
11814 The command above lists a set of packages that could be built to check
11815 for compatibility with an upgraded @code{flex} package.
11819 @item --list-transitive
11820 List all the packages which one or more packages depend upon.
11823 $ guix refresh --list-transitive flex
11824 flex@@2.6.4 depends on the following 25 packages: perl@@5.28.0 help2man@@1.47.6
11825 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{}
11830 The command above lists a set of packages which, when changed, would cause
11831 @code{flex} to be rebuilt.
11833 The following options can be used to customize GnuPG operation:
11837 @item --gpg=@var{command}
11838 Use @var{command} as the GnuPG 2.x command. @var{command} is searched
11839 for in @code{$PATH}.
11841 @item --keyring=@var{file}
11842 Use @var{file} as the keyring for upstream keys. @var{file} must be in the
11843 @dfn{keybox format}. Keybox files usually have a name ending in @file{.kbx}
11844 and the GNU@tie{}Privacy Guard (GPG) can manipulate these files
11845 (@pxref{kbxutil, @command{kbxutil},, gnupg, Using the GNU Privacy Guard}, for
11846 information on a tool to manipulate keybox files).
11848 When this option is omitted, @command{guix refresh} uses
11849 @file{~/.config/guix/upstream/trustedkeys.kbx} as the keyring for upstream
11850 signing keys. OpenPGP signatures are checked against keys from this keyring;
11851 missing keys are downloaded to this keyring as well (see
11852 @option{--key-download} below).
11854 You can export keys from your default GPG keyring into a keybox file using
11855 commands like this one:
11858 gpg --export rms@@gnu.org | kbxutil --import-openpgp >> mykeyring.kbx
11861 Likewise, you can fetch keys to a specific keybox file like this:
11864 gpg --no-default-keyring --keyring mykeyring.kbx \
11865 --recv-keys @value{OPENPGP-SIGNING-KEY-ID}
11868 @xref{GPG Configuration Options, @option{--keyring},, gnupg, Using the GNU
11869 Privacy Guard}, for more information on GPG's @option{--keyring} option.
11871 @item --key-download=@var{policy}
11872 Handle missing OpenPGP keys according to @var{policy}, which may be one
11877 Always download missing OpenPGP keys from the key server, and add them
11878 to the user's GnuPG keyring.
11881 Never try to download missing OpenPGP keys. Instead just bail out.
11884 When a package signed with an unknown OpenPGP key is encountered, ask
11885 the user whether to download it or not. This is the default behavior.
11888 @item --key-server=@var{host}
11889 Use @var{host} as the OpenPGP key server when importing a public key.
11891 @item --load-path=@var{directory}
11892 Add @var{directory} to the front of the package module search path
11893 (@pxref{Package Modules}).
11895 This allows users to define their own packages and make them visible to
11896 the command-line tools.
11900 The @code{github} updater uses the
11901 @uref{https://developer.github.com/v3/, GitHub API} to query for new
11902 releases. When used repeatedly e.g.@: when refreshing all packages,
11903 GitHub will eventually refuse to answer any further API requests. By
11904 default 60 API requests per hour are allowed, and a full refresh on all
11905 GitHub packages in Guix requires more than this. Authentication with
11906 GitHub through the use of an API token alleviates these limits. To use
11907 an API token, set the environment variable @env{GUIX_GITHUB_TOKEN} to a
11908 token procured from @uref{https://github.com/settings/tokens} or
11912 @node Invoking guix lint
11913 @section Invoking @command{guix lint}
11915 @cindex @command{guix lint}
11916 @cindex package, checking for errors
11917 The @command{guix lint} command is meant to help package developers avoid
11918 common errors and use a consistent style. It runs a number of checks on
11919 a given set of packages in order to find common mistakes in their
11920 definitions. Available @dfn{checkers} include (see
11921 @option{--list-checkers} for a complete list):
11926 Validate certain typographical and stylistic rules about package
11927 descriptions and synopses.
11929 @item inputs-should-be-native
11930 Identify inputs that should most likely be native inputs.
11936 @itemx source-file-name
11937 Probe @code{home-page} and @code{source} URLs and report those that are
11938 invalid. Suggest a @code{mirror://} URL when applicable. If the
11939 @code{source} URL redirects to a GitHub URL, recommend usage of the GitHub
11940 URL@. Check that the source file name is meaningful, e.g.@: is not just a
11941 version number or ``git-checkout'', without a declared @code{file-name}
11942 (@pxref{origin Reference}).
11944 @item source-unstable-tarball
11945 Parse the @code{source} URL to determine if a tarball from GitHub is
11946 autogenerated or if it is a release tarball. Unfortunately GitHub's
11947 autogenerated tarballs are sometimes regenerated.
11950 Check that the derivation of the given packages can be successfully
11951 computed for all the supported systems (@pxref{Derivations}).
11953 @item profile-collisions
11954 Check whether installing the given packages in a profile would lead to
11955 collisions. Collisions occur when several packages with the same name
11956 but a different version or a different store file name are propagated.
11957 @xref{package Reference, @code{propagated-inputs}}, for more information
11958 on propagated inputs.
11961 @cindex Software Heritage, source code archive
11962 @cindex archival of source code, Software Heritage
11963 Checks whether the package's source code is archived at
11964 @uref{https://www.softwareheritage.org, Software Heritage}.
11966 When the source code that is not archived comes from a version-control system
11967 (VCS)---e.g., it's obtained with @code{git-fetch}, send Software Heritage a
11968 ``save'' request so that it eventually archives it. This ensures that the
11969 source will remain available in the long term, and that Guix can fall back to
11970 Software Heritage should the source code disappear from its original host.
11971 The status of recent ``save'' requests can be
11972 @uref{https://archive.softwareheritage.org/save/#requests, viewed on-line}.
11974 When source code is a tarball obtained with @code{url-fetch}, simply print a
11975 message when it is not archived. As of this writing, Software Heritage does
11976 not allow requests to save arbitrary tarballs; we are working on ways to
11977 ensure that non-VCS source code is also archived.
11980 @uref{https://archive.softwareheritage.org/api/#rate-limiting, limits the
11981 request rate per IP address}. When the limit is reached, @command{guix lint}
11982 prints a message and the @code{archival} checker stops doing anything until
11983 that limit has been reset.
11986 @cindex security vulnerabilities
11987 @cindex CVE, Common Vulnerabilities and Exposures
11988 Report known vulnerabilities found in the Common Vulnerabilities and
11989 Exposures (CVE) databases of the current and past year
11990 @uref{https://nvd.nist.gov/vuln/data-feeds, published by the US
11993 To view information about a particular vulnerability, visit pages such as:
11997 @indicateurl{https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-YYYY-ABCD}
11999 @indicateurl{https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-YYYY-ABCD}
12003 where @code{CVE-YYYY-ABCD} is the CVE identifier---e.g.,
12004 @code{CVE-2015-7554}.
12006 Package developers can specify in package recipes the
12007 @uref{https://nvd.nist.gov/products/cpe,Common Platform Enumeration (CPE)}
12008 name and version of the package when they differ from the name or version
12009 that Guix uses, as in this example:
12015 ;; CPE calls this package "grub2".
12016 (properties '((cpe-name . "grub2")
12017 (cpe-version . "2.3"))))
12020 @c See <https://www.openwall.com/lists/oss-security/2017/03/15/3>.
12021 Some entries in the CVE database do not specify which version of a
12022 package they apply to, and would thus ``stick around'' forever. Package
12023 developers who found CVE alerts and verified they can be ignored can
12024 declare them as in this example:
12030 ;; These CVEs no longer apply and can be safely ignored.
12031 (properties `((lint-hidden-cve . ("CVE-2011-0433"
12034 "CVE-2011-5244")))))
12038 Warn about obvious source code formatting issues: trailing white space,
12039 use of tabulations, etc.
12042 The general syntax is:
12045 guix lint @var{options} @var{package}@dots{}
12048 If no package is given on the command line, then all packages are checked.
12049 The @var{options} may be zero or more of the following:
12052 @item --list-checkers
12054 List and describe all the available checkers that will be run on packages
12059 Only enable the checkers specified in a comma-separated list using the
12060 names returned by @option{--list-checkers}.
12064 Only disable the checkers specified in a comma-separated list using the
12065 names returned by @option{--list-checkers}.
12069 Only enable the checkers that do not depend on Internet access.
12071 @item --load-path=@var{directory}
12072 @itemx -L @var{directory}
12073 Add @var{directory} to the front of the package module search path
12074 (@pxref{Package Modules}).
12076 This allows users to define their own packages and make them visible to
12077 the command-line tools.
12081 @node Invoking guix size
12082 @section Invoking @command{guix size}
12085 @cindex package size
12087 @cindex @command{guix size}
12088 The @command{guix size} command helps package developers profile the
12089 disk usage of packages. It is easy to overlook the impact of an
12090 additional dependency added to a package, or the impact of using a
12091 single output for a package that could easily be split (@pxref{Packages
12092 with Multiple Outputs}). Such are the typical issues that
12093 @command{guix size} can highlight.
12095 The command can be passed one or more package specifications
12096 such as @code{gcc@@4.8}
12097 or @code{guile:debug}, or a file name in the store. Consider this
12101 $ guix size coreutils
12102 store item total self
12103 /gnu/store/@dots{}-gcc-5.5.0-lib 60.4 30.1 38.1%
12104 /gnu/store/@dots{}-glibc-2.27 30.3 28.8 36.6%
12105 /gnu/store/@dots{}-coreutils-8.28 78.9 15.0 19.0%
12106 /gnu/store/@dots{}-gmp-6.1.2 63.1 2.7 3.4%
12107 /gnu/store/@dots{}-bash-static-4.4.12 1.5 1.5 1.9%
12108 /gnu/store/@dots{}-acl-2.2.52 61.1 0.4 0.5%
12109 /gnu/store/@dots{}-attr-2.4.47 60.6 0.2 0.3%
12110 /gnu/store/@dots{}-libcap-2.25 60.5 0.2 0.2%
12115 The store items listed here constitute the @dfn{transitive closure} of
12116 Coreutils---i.e., Coreutils and all its dependencies, recursively---as
12117 would be returned by:
12120 $ guix gc -R /gnu/store/@dots{}-coreutils-8.23
12123 Here the output shows three columns next to store items. The first column,
12124 labeled ``total'', shows the size in mebibytes (MiB) of the closure of
12125 the store item---that is, its own size plus the size of all its
12126 dependencies. The next column, labeled ``self'', shows the size of the
12127 item itself. The last column shows the ratio of the size of the item
12128 itself to the space occupied by all the items listed here.
12130 In this example, we see that the closure of Coreutils weighs in at
12131 79@tie{}MiB, most of which is taken by libc and GCC's run-time support
12132 libraries. (That libc and GCC's libraries represent a large fraction of
12133 the closure is not a problem @i{per se} because they are always available
12134 on the system anyway.)
12136 Since the command also accepts store file names, assessing the size of
12137 a build result is straightforward:
12140 guix size $(guix system build config.scm)
12143 When the package(s) passed to @command{guix size} are available in the
12144 store@footnote{More precisely, @command{guix size} looks for the
12145 @emph{ungrafted} variant of the given package(s), as returned by
12146 @code{guix build @var{package} --no-grafts}. @xref{Security Updates},
12147 for information on grafts.}, @command{guix size} queries the daemon to determine its
12148 dependencies, and measures its size in the store, similar to @command{du
12149 -ms --apparent-size} (@pxref{du invocation,,, coreutils, GNU
12152 When the given packages are @emph{not} in the store, @command{guix size}
12153 reports information based on the available substitutes
12154 (@pxref{Substitutes}). This makes it possible it to profile disk usage of
12155 store items that are not even on disk, only available remotely.
12157 You can also specify several package names:
12160 $ guix size coreutils grep sed bash
12161 store item total self
12162 /gnu/store/@dots{}-coreutils-8.24 77.8 13.8 13.4%
12163 /gnu/store/@dots{}-grep-2.22 73.1 0.8 0.8%
12164 /gnu/store/@dots{}-bash-4.3.42 72.3 4.7 4.6%
12165 /gnu/store/@dots{}-readline-6.3 67.6 1.2 1.2%
12171 In this example we see that the combination of the four packages takes
12172 102.3@tie{}MiB in total, which is much less than the sum of each closure
12173 since they have a lot of dependencies in common.
12175 When looking at the profile returned by @command{guix size}, you may
12176 find yourself wondering why a given package shows up in the profile at
12177 all. To understand it, you can use @command{guix graph --path -t
12178 references} to display the shortest path between the two packages
12179 (@pxref{Invoking guix graph}).
12181 The available options are:
12185 @item --substitute-urls=@var{urls}
12186 Use substitute information from @var{urls}.
12187 @xref{client-substitute-urls, the same option for @code{guix build}}.
12189 @item --sort=@var{key}
12190 Sort lines according to @var{key}, one of the following options:
12194 the size of each item (the default);
12196 the total size of the item's closure.
12199 @item --map-file=@var{file}
12200 Write a graphical map of disk usage in PNG format to @var{file}.
12202 For the example above, the map looks like this:
12204 @image{images/coreutils-size-map,5in,, map of Coreutils disk usage
12205 produced by @command{guix size}}
12207 This option requires that
12208 @uref{https://wingolog.org/software/guile-charting/, Guile-Charting} be
12209 installed and visible in Guile's module search path. When that is not
12210 the case, @command{guix size} fails as it tries to load it.
12212 @item --system=@var{system}
12213 @itemx -s @var{system}
12214 Consider packages for @var{system}---e.g., @code{x86_64-linux}.
12216 @item --load-path=@var{directory}
12217 @itemx -L @var{directory}
12218 Add @var{directory} to the front of the package module search path
12219 (@pxref{Package Modules}).
12221 This allows users to define their own packages and make them visible to
12222 the command-line tools.
12225 @node Invoking guix graph
12226 @section Invoking @command{guix graph}
12229 @cindex @command{guix graph}
12230 @cindex package dependencies
12231 Packages and their dependencies form a @dfn{graph}, specifically a
12232 directed acyclic graph (DAG). It can quickly become difficult to have a
12233 mental model of the package DAG, so the @command{guix graph} command
12234 provides a visual representation of the DAG@. By default,
12235 @command{guix graph} emits a DAG representation in the input format of
12236 @uref{https://www.graphviz.org/, Graphviz}, so its output can be passed
12237 directly to the @command{dot} command of Graphviz. It can also emit an
12238 HTML page with embedded JavaScript code to display a ``chord diagram''
12239 in a Web browser, using the @uref{https://d3js.org/, d3.js} library, or
12240 emit Cypher queries to construct a graph in a graph database supporting
12241 the @uref{https://www.opencypher.org/, openCypher} query language. With
12242 @option{--path}, it simply displays the shortest path between two
12243 packages. The general syntax is:
12246 guix graph @var{options} @var{package}@dots{}
12249 For example, the following command generates a PDF file representing the
12250 package DAG for the GNU@tie{}Core Utilities, showing its build-time
12254 guix graph coreutils | dot -Tpdf > dag.pdf
12257 The output looks like this:
12259 @image{images/coreutils-graph,2in,,Dependency graph of the GNU Coreutils}
12261 Nice little graph, no?
12263 You may find it more pleasant to navigate the graph interactively with
12264 @command{xdot} (from the @code{xdot} package):
12267 guix graph coreutils | xdot -
12270 But there is more than one graph! The one above is concise: it is the
12271 graph of package objects, omitting implicit inputs such as GCC, libc,
12272 grep, etc. It is often useful to have such a concise graph, but
12273 sometimes one may want to see more details. @command{guix graph} supports
12274 several types of graphs, allowing you to choose the level of detail:
12278 This is the default type used in the example above. It shows the DAG of
12279 package objects, excluding implicit dependencies. It is concise, but
12280 filters out many details.
12282 @item reverse-package
12283 This shows the @emph{reverse} DAG of packages. For example:
12286 guix graph --type=reverse-package ocaml
12289 ...@: yields the graph of packages that @emph{explicitly} depend on OCaml (if
12290 you are also interested in cases where OCaml is an implicit dependency, see
12291 @code{reverse-bag} below).
12293 Note that for core packages this can yield huge graphs. If all you want
12294 is to know the number of packages that depend on a given package, use
12295 @command{guix refresh --list-dependent} (@pxref{Invoking guix refresh,
12296 @option{--list-dependent}}).
12299 This is the package DAG, @emph{including} implicit inputs.
12301 For instance, the following command:
12304 guix graph --type=bag-emerged coreutils
12307 ...@: yields this bigger graph:
12309 @image{images/coreutils-bag-graph,,5in,Detailed dependency graph of the GNU Coreutils}
12311 At the bottom of the graph, we see all the implicit inputs of
12312 @var{gnu-build-system} (@pxref{Build Systems, @code{gnu-build-system}}).
12314 Now, note that the dependencies of these implicit inputs---that is, the
12315 @dfn{bootstrap dependencies} (@pxref{Bootstrapping})---are not shown
12316 here, for conciseness.
12319 Similar to @code{bag-emerged}, but this time including all the bootstrap
12322 @item bag-with-origins
12323 Similar to @code{bag}, but also showing origins and their dependencies.
12326 This shows the @emph{reverse} DAG of packages. Unlike @code{reverse-package},
12327 it also takes implicit dependencies into account. For example:
12330 guix graph -t reverse-bag dune
12334 ...@: yields the graph of all packages that depend on Dune, directly or
12335 indirectly. Since Dune is an @emph{implicit} dependency of many packages
12336 @i{via} @code{dune-build-system}, this shows a large number of packages,
12337 whereas @code{reverse-package} would show very few if any.
12340 This is the most detailed representation: It shows the DAG of
12341 derivations (@pxref{Derivations}) and plain store items. Compared to
12342 the above representation, many additional nodes are visible, including
12343 build scripts, patches, Guile modules, etc.
12345 For this type of graph, it is also possible to pass a @file{.drv} file
12346 name instead of a package name, as in:
12349 guix graph -t derivation `guix system build -d my-config.scm`
12353 This is the graph of @dfn{package modules} (@pxref{Package Modules}).
12354 For example, the following command shows the graph for the package
12355 module that defines the @code{guile} package:
12358 guix graph -t module guile | xdot -
12362 All the types above correspond to @emph{build-time dependencies}. The
12363 following graph type represents the @emph{run-time dependencies}:
12367 This is the graph of @dfn{references} of a package output, as returned
12368 by @command{guix gc --references} (@pxref{Invoking guix gc}).
12370 If the given package output is not available in the store, @command{guix
12371 graph} attempts to obtain dependency information from substitutes.
12373 Here you can also pass a store file name instead of a package name. For
12374 example, the command below produces the reference graph of your profile
12375 (which can be big!):
12378 guix graph -t references `readlink -f ~/.guix-profile`
12382 This is the graph of the @dfn{referrers} of a store item, as returned by
12383 @command{guix gc --referrers} (@pxref{Invoking guix gc}).
12385 This relies exclusively on local information from your store. For
12386 instance, let us suppose that the current Inkscape is available in 10
12387 profiles on your machine; @command{guix graph -t referrers inkscape}
12388 will show a graph rooted at Inkscape and with those 10 profiles linked
12391 It can help determine what is preventing a store item from being garbage
12396 @cindex shortest path, between packages
12397 Often, the graph of the package you are interested in does not fit on
12398 your screen, and anyway all you want to know is @emph{why} that package
12399 actually depends on some seemingly unrelated package. The
12400 @option{--path} option instructs @command{guix graph} to display the
12401 shortest path between two packages (or derivations, or store items,
12405 $ guix graph --path emacs libunistring
12408 libunistring@@0.9.10
12409 $ guix graph --path -t derivation emacs libunistring
12410 /gnu/store/@dots{}-emacs-26.3.drv
12411 /gnu/store/@dots{}-mailutils-3.9.drv
12412 /gnu/store/@dots{}-libunistring-0.9.10.drv
12413 $ guix graph --path -t references emacs libunistring
12414 /gnu/store/@dots{}-emacs-26.3
12415 /gnu/store/@dots{}-libidn2-2.2.0
12416 /gnu/store/@dots{}-libunistring-0.9.10
12419 The available options are the following:
12422 @item --type=@var{type}
12423 @itemx -t @var{type}
12424 Produce a graph output of @var{type}, where @var{type} must be one of
12425 the values listed above.
12428 List the supported graph types.
12430 @item --backend=@var{backend}
12431 @itemx -b @var{backend}
12432 Produce a graph using the selected @var{backend}.
12434 @item --list-backends
12435 List the supported graph backends.
12437 Currently, the available backends are Graphviz and d3.js.
12440 Display the shortest path between two nodes of the type specified by
12441 @option{--type}. The example below shows the shortest path between
12442 @code{libreoffice} and @code{llvm} according to the references of
12443 @code{libreoffice}:
12446 $ guix graph --path -t references libreoffice llvm
12447 /gnu/store/@dots{}-libreoffice-6.4.2.2
12448 /gnu/store/@dots{}-libepoxy-1.5.4
12449 /gnu/store/@dots{}-mesa-19.3.4
12450 /gnu/store/@dots{}-llvm-9.0.1
12453 @item --expression=@var{expr}
12454 @itemx -e @var{expr}
12455 Consider the package @var{expr} evaluates to.
12457 This is useful to precisely refer to a package, as in this example:
12460 guix graph -e '(@@@@ (gnu packages commencement) gnu-make-final)'
12463 @item --system=@var{system}
12464 @itemx -s @var{system}
12465 Display the graph for @var{system}---e.g., @code{i686-linux}.
12467 The package dependency graph is largely architecture-independent, but there
12468 are some architecture-dependent bits that this option allows you to visualize.
12470 @item --load-path=@var{directory}
12471 @itemx -L @var{directory}
12472 Add @var{directory} to the front of the package module search path
12473 (@pxref{Package Modules}).
12475 This allows users to define their own packages and make them visible to
12476 the command-line tools.
12479 On top of that, @command{guix graph} supports all the usual package
12480 transformation options (@pxref{Package Transformation Options}). This
12481 makes it easy to view the effect of a graph-rewriting transformation
12482 such as @option{--with-input}. For example, the command below outputs
12483 the graph of @code{git} once @code{openssl} has been replaced by
12484 @code{libressl} everywhere in the graph:
12487 guix graph git --with-input=openssl=libressl
12490 So many possibilities, so much fun!
12492 @node Invoking guix publish
12493 @section Invoking @command{guix publish}
12495 @cindex @command{guix publish}
12496 The purpose of @command{guix publish} is to enable users to easily share
12497 their store with others, who can then use it as a substitute server
12498 (@pxref{Substitutes}).
12500 When @command{guix publish} runs, it spawns an HTTP server which allows
12501 anyone with network access to obtain substitutes from it. This means
12502 that any machine running Guix can also act as if it were a build farm,
12503 since the HTTP interface is compatible with Cuirass, the software behind
12504 the @code{@value{SUBSTITUTE-SERVER}} build farm.
12506 For security, each substitute is signed, allowing recipients to check
12507 their authenticity and integrity (@pxref{Substitutes}). Because
12508 @command{guix publish} uses the signing key of the system, which is only
12509 readable by the system administrator, it must be started as root; the
12510 @option{--user} option makes it drop root privileges early on.
12512 The signing key pair must be generated before @command{guix publish} is
12513 launched, using @command{guix archive --generate-key} (@pxref{Invoking
12516 When the @option{--advertise} option is passed, the server advertises
12517 its availability on the local network using multicast DNS (mDNS) and DNS
12518 service discovery (DNS-SD), currently @i{via} Guile-Avahi (@pxref{Top,,,
12519 guile-avahi, Using Avahi in Guile Scheme Programs}).
12521 The general syntax is:
12524 guix publish @var{options}@dots{}
12527 Running @command{guix publish} without any additional arguments will
12528 spawn an HTTP server on port 8080:
12534 Once a publishing server has been authorized, the daemon may download
12535 substitutes from it. @xref{Getting Substitutes from Other Servers}.
12537 By default, @command{guix publish} compresses archives on the fly as it
12538 serves them. This ``on-the-fly'' mode is convenient in that it requires
12539 no setup and is immediately available. However, when serving lots of
12540 clients, we recommend using the @option{--cache} option, which enables
12541 caching of the archives before they are sent to clients---see below for
12542 details. The @command{guix weather} command provides a handy way to
12543 check what a server provides (@pxref{Invoking guix weather}).
12545 As a bonus, @command{guix publish} also serves as a content-addressed
12546 mirror for source files referenced in @code{origin} records
12547 (@pxref{origin Reference}). For instance, assuming @command{guix
12548 publish} is running on @code{example.org}, the following URL returns the
12549 raw @file{hello-2.10.tar.gz} file with the given SHA256 hash
12550 (represented in @code{nix-base32} format, @pxref{Invoking guix hash}):
12553 http://example.org/file/hello-2.10.tar.gz/sha256/0ssi1@dots{}ndq1i
12556 Obviously, these URLs only work for files that are in the store; in
12557 other cases, they return 404 (``Not Found'').
12559 @cindex build logs, publication
12560 Build logs are available from @code{/log} URLs like:
12563 http://example.org/log/gwspk@dots{}-guile-2.2.3
12567 When @command{guix-daemon} is configured to save compressed build logs,
12568 as is the case by default (@pxref{Invoking guix-daemon}), @code{/log}
12569 URLs return the compressed log as-is, with an appropriate
12570 @code{Content-Type} and/or @code{Content-Encoding} header. We recommend
12571 running @command{guix-daemon} with @option{--log-compression=gzip} since
12572 Web browsers can automatically decompress it, which is not the case with
12575 The following options are available:
12578 @item --port=@var{port}
12579 @itemx -p @var{port}
12580 Listen for HTTP requests on @var{port}.
12582 @item --listen=@var{host}
12583 Listen on the network interface for @var{host}. The default is to
12584 accept connections from any interface.
12586 @item --user=@var{user}
12587 @itemx -u @var{user}
12588 Change privileges to @var{user} as soon as possible---i.e., once the
12589 server socket is open and the signing key has been read.
12591 @item --compression[=@var{method}[:@var{level}]]
12592 @itemx -C [@var{method}[:@var{level}]]
12593 Compress data using the given @var{method} and @var{level}. @var{method} is
12594 one of @code{lzip}, @code{zstd}, and @code{gzip}; when @var{method} is
12595 omitted, @code{gzip} is used.
12597 When @var{level} is zero, disable compression. The range 1 to 9 corresponds
12598 to different compression levels: 1 is the fastest, and 9 is the best
12599 (CPU-intensive). The default is 3.
12601 Usually, @code{lzip} compresses noticeably better than @code{gzip} for a
12602 small increase in CPU usage; see
12603 @uref{https://nongnu.org/lzip/lzip_benchmark.html,benchmarks on the lzip
12604 Web page}. However, @code{lzip} achieves low decompression throughput
12605 (on the order of 50@tie{}MiB/s on modern hardware), which can be a
12606 bottleneck for someone who downloads over a fast network connection.
12608 The compression ratio of @code{zstd} is between that of @code{lzip} and
12609 that of @code{gzip}; its main advantage is a
12610 @uref{https://facebook.github.io/zstd/,high decompression speed}.
12612 Unless @option{--cache} is used, compression occurs on the fly and
12613 the compressed streams are not
12614 cached. Thus, to reduce load on the machine that runs @command{guix
12615 publish}, it may be a good idea to choose a low compression level, to
12616 run @command{guix publish} behind a caching proxy, or to use
12617 @option{--cache}. Using @option{--cache} has the advantage that it
12618 allows @command{guix publish} to add @code{Content-Length} HTTP header
12621 This option can be repeated, in which case every substitute gets compressed
12622 using all the selected methods, and all of them are advertised. This is
12623 useful when users may not support all the compression methods: they can select
12624 the one they support.
12626 @item --cache=@var{directory}
12627 @itemx -c @var{directory}
12628 Cache archives and meta-data (@code{.narinfo} URLs) to @var{directory}
12629 and only serve archives that are in cache.
12631 When this option is omitted, archives and meta-data are created
12632 on-the-fly. This can reduce the available bandwidth, especially when
12633 compression is enabled, since this may become CPU-bound. Another
12634 drawback of the default mode is that the length of archives is not known
12635 in advance, so @command{guix publish} does not add a
12636 @code{Content-Length} HTTP header to its responses, which in turn
12637 prevents clients from knowing the amount of data being downloaded.
12639 Conversely, when @option{--cache} is used, the first request for a store
12640 item (@i{via} a @code{.narinfo} URL) triggers a
12641 background process to @dfn{bake} the archive---computing its
12642 @code{.narinfo} and compressing the archive, if needed. Once the
12643 archive is cached in @var{directory}, subsequent requests succeed and
12644 are served directly from the cache, which guarantees that clients get
12645 the best possible bandwidth.
12647 That first @code{.narinfo} request nonetheless returns 200, provided the
12648 requested store item is ``small enough'', below the cache bypass
12649 threshold---see @option{--cache-bypass-threshold} below. That way,
12650 clients do not have to wait until the archive is baked. For larger
12651 store items, the first @code{.narinfo} request returns 404, meaning that
12652 clients have to wait until the archive is baked.
12654 The ``baking'' process is performed by worker threads. By default, one
12655 thread per CPU core is created, but this can be customized. See
12656 @option{--workers} below.
12658 When @option{--ttl} is used, cached entries are automatically deleted
12659 when they have expired.
12661 @item --workers=@var{N}
12662 When @option{--cache} is used, request the allocation of @var{N} worker
12663 threads to ``bake'' archives.
12665 @item --ttl=@var{ttl}
12666 Produce @code{Cache-Control} HTTP headers that advertise a time-to-live
12667 (TTL) of @var{ttl}. @var{ttl} must denote a duration: @code{5d} means 5
12668 days, @code{1m} means 1 month, and so on.
12670 This allows the user's Guix to keep substitute information in cache for
12671 @var{ttl}. However, note that @code{guix publish} does not itself
12672 guarantee that the store items it provides will indeed remain available
12673 for as long as @var{ttl}.
12675 Additionally, when @option{--cache} is used, cached entries that have
12676 not been accessed for @var{ttl} and that no longer have a corresponding
12677 item in the store, may be deleted.
12679 @item --cache-bypass-threshold=@var{size}
12680 When used in conjunction with @option{--cache}, store items smaller than
12681 @var{size} are immediately available, even when they are not yet in
12682 cache. @var{size} is a size in bytes, or it can be suffixed by @code{M}
12683 for megabytes and so on. The default is @code{10M}.
12685 ``Cache bypass'' allows you to reduce the publication delay for clients
12686 at the expense of possibly additional I/O and CPU use on the server
12687 side: depending on the client access patterns, those store items can end
12688 up being baked several times until a copy is available in cache.
12690 Increasing the threshold may be useful for sites that have few users, or
12691 to guarantee that users get substitutes even for store items that are
12694 @item --nar-path=@var{path}
12695 Use @var{path} as the prefix for the URLs of ``nar'' files
12696 (@pxref{Invoking guix archive, normalized archives}).
12698 By default, nars are served at a URL such as
12699 @code{/nar/gzip/@dots{}-coreutils-8.25}. This option allows you to
12700 change the @code{/nar} part to @var{path}.
12702 @item --public-key=@var{file}
12703 @itemx --private-key=@var{file}
12704 Use the specific @var{file}s as the public/private key pair used to sign
12705 the store items being published.
12707 The files must correspond to the same key pair (the private key is used
12708 for signing and the public key is merely advertised in the signature
12709 metadata). They must contain keys in the canonical s-expression format
12710 as produced by @command{guix archive --generate-key} (@pxref{Invoking
12711 guix archive}). By default, @file{/etc/guix/signing-key.pub} and
12712 @file{/etc/guix/signing-key.sec} are used.
12714 @item --repl[=@var{port}]
12715 @itemx -r [@var{port}]
12716 Spawn a Guile REPL server (@pxref{REPL Servers,,, guile, GNU Guile
12717 Reference Manual}) on @var{port} (37146 by default). This is used
12718 primarily for debugging a running @command{guix publish} server.
12721 Enabling @command{guix publish} on Guix System is a one-liner: just
12722 instantiate a @code{guix-publish-service-type} service in the @code{services} field
12723 of the @code{operating-system} declaration (@pxref{guix-publish-service-type,
12724 @code{guix-publish-service-type}}).
12726 If you are instead running Guix on a ``foreign distro'', follow these
12731 If your host distro uses the systemd init system:
12734 # ln -s ~root/.guix-profile/lib/systemd/system/guix-publish.service \
12735 /etc/systemd/system/
12736 # systemctl start guix-publish && systemctl enable guix-publish
12740 If your host distro uses the Upstart init system:
12743 # ln -s ~root/.guix-profile/lib/upstart/system/guix-publish.conf /etc/init/
12744 # start guix-publish
12748 Otherwise, proceed similarly with your distro's init system.
12751 @node Invoking guix challenge
12752 @section Invoking @command{guix challenge}
12754 @cindex reproducible builds
12755 @cindex verifiable builds
12756 @cindex @command{guix challenge}
12758 Do the binaries provided by this server really correspond to the source
12759 code it claims to build? Is a package build process deterministic?
12760 These are the questions the @command{guix challenge} command attempts to
12763 The former is obviously an important question: Before using a substitute
12764 server (@pxref{Substitutes}), one had better @emph{verify} that it
12765 provides the right binaries, and thus @emph{challenge} it. The latter
12766 is what enables the former: If package builds are deterministic, then
12767 independent builds of the package should yield the exact same result,
12768 bit for bit; if a server provides a binary different from the one
12769 obtained locally, it may be either corrupt or malicious.
12771 We know that the hash that shows up in @file{/gnu/store} file names is
12772 the hash of all the inputs of the process that built the file or
12773 directory---compilers, libraries, build scripts,
12774 etc. (@pxref{Introduction}). Assuming deterministic build processes,
12775 one store file name should map to exactly one build output.
12776 @command{guix challenge} checks whether there is, indeed, a single
12777 mapping by comparing the build outputs of several independent builds of
12778 any given store item.
12780 The command output looks like this:
12783 $ guix challenge --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12784 updating list of substitutes from 'https://@value{SUBSTITUTE-SERVER}'... 100.0%
12785 updating list of substitutes from 'https://guix.example.org'... 100.0%
12786 /gnu/store/@dots{}-openssl-1.0.2d contents differ:
12787 local hash: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12788 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-openssl-1.0.2d: 0725l22r5jnzazaacncwsvp9kgf42266ayyp814v7djxs7nk963q
12789 https://guix.example.org/nar/@dots{}-openssl-1.0.2d: 1zy4fmaaqcnjrzzajkdn3f5gmjk754b43qkq47llbyak9z0qjyim
12791 /lib/libcrypto.so.1.1
12794 /gnu/store/@dots{}-git-2.5.0 contents differ:
12795 local hash: 00p3bmryhjxrhpn2gxs2fy0a15lnip05l97205pgbk5ra395hyha
12796 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-git-2.5.0: 069nb85bv4d4a6slrwjdy8v1cn4cwspm3kdbmyb81d6zckj3nq9f
12797 https://guix.example.org/nar/@dots{}-git-2.5.0: 0mdqa9w1p6cmli6976v4wi0sw9r4p5prkj7lzfd1877wk11c9c73
12799 /libexec/git-core/git-fsck
12801 /gnu/store/@dots{}-pius-2.1.1 contents differ:
12802 local hash: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12803 https://@value{SUBSTITUTE-SERVER}/nar/@dots{}-pius-2.1.1: 0k4v3m9z1zp8xzzizb7d8kjj72f9172xv078sq4wl73vnq9ig3ax
12804 https://guix.example.org/nar/@dots{}-pius-2.1.1: 1cy25x1a4fzq5rk0pmvc8xhwyffnqz95h2bpvqsz2mpvlbccy0gs
12806 /share/man/man1/pius.1.gz
12810 6,406 store items were analyzed:
12811 - 4,749 (74.1%) were identical
12812 - 525 (8.2%) differed
12813 - 1,132 (17.7%) were inconclusive
12817 In this example, @command{guix challenge} first scans the store to
12818 determine the set of locally-built derivations---as opposed to store
12819 items that were downloaded from a substitute server---and then queries
12820 all the substitute servers. It then reports those store items for which
12821 the servers obtained a result different from the local build.
12823 @cindex non-determinism, in package builds
12824 As an example, @code{guix.example.org} always gets a different answer.
12825 Conversely, @code{@value{SUBSTITUTE-SERVER}} agrees with local builds, except in the
12826 case of Git. This might indicate that the build process of Git is
12827 non-deterministic, meaning that its output varies as a function of
12828 various things that Guix does not fully control, in spite of building
12829 packages in isolated environments (@pxref{Features}). Most common
12830 sources of non-determinism include the addition of timestamps in build
12831 results, the inclusion of random numbers, and directory listings sorted
12832 by inode number. See @uref{https://reproducible-builds.org/docs/}, for
12835 To find out what is wrong with this Git binary, the easiest approach is
12839 guix challenge git \
12840 --diff=diffoscope \
12841 --substitute-urls="https://@value{SUBSTITUTE-SERVER} https://guix.example.org"
12844 This automatically invokes @command{diffoscope}, which displays detailed
12845 information about files that differ.
12847 Alternatively, we can do something along these lines (@pxref{Invoking guix
12851 $ wget -q -O - https://@value{SUBSTITUTE-SERVER}/nar/lzip/@dots{}-git-2.5.0 \
12852 | lzip -d | guix archive -x /tmp/git
12853 $ diff -ur --no-dereference /gnu/store/@dots{}-git.2.5.0 /tmp/git
12856 This command shows the difference between the files resulting from the
12857 local build, and the files resulting from the build on
12858 @code{@value{SUBSTITUTE-SERVER}} (@pxref{Overview, Comparing and Merging Files,,
12859 diffutils, Comparing and Merging Files}). The @command{diff} command
12860 works great for text files. When binary files differ, a better option
12861 is @uref{https://diffoscope.org/, Diffoscope}, a tool that helps
12862 visualize differences for all kinds of files.
12864 Once you have done that work, you can tell whether the differences are due
12865 to a non-deterministic build process or to a malicious server. We try
12866 hard to remove sources of non-determinism in packages to make it easier
12867 to verify substitutes, but of course, this is a process that
12868 involves not just Guix, but a large part of the free software community.
12869 In the meantime, @command{guix challenge} is one tool to help address
12872 If you are writing packages for Guix, you are encouraged to check
12873 whether @code{@value{SUBSTITUTE-SERVER}} and other substitute servers obtain the
12874 same build result as you did with:
12877 $ guix challenge @var{package}
12881 where @var{package} is a package specification such as
12882 @code{guile@@2.0} or @code{glibc:debug}.
12884 The general syntax is:
12887 guix challenge @var{options} [@var{packages}@dots{}]
12890 When a difference is found between the hash of a locally-built item and
12891 that of a server-provided substitute, or among substitutes provided by
12892 different servers, the command displays it as in the example above and
12893 its exit code is 2 (other non-zero exit codes denote other kinds of
12896 The one option that matters is:
12900 @item --substitute-urls=@var{urls}
12901 Consider @var{urls} the whitespace-separated list of substitute source
12902 URLs to compare to.
12904 @item --diff=@var{mode}
12905 Upon mismatches, show differences according to @var{mode}, one of:
12908 @item @code{simple} (the default)
12909 Show the list of files that differ.
12911 @item @code{diffoscope}
12912 @itemx @var{command}
12913 Invoke @uref{https://diffoscope.org/, Diffoscope}, passing it
12914 two directories whose contents do not match.
12916 When @var{command} is an absolute file name, run @var{command} instead
12920 Do not show further details about the differences.
12923 Thus, unless @option{--diff=none} is passed, @command{guix challenge}
12924 downloads the store items from the given substitute servers so that it
12929 Show details about matches (identical contents) in addition to
12930 information about mismatches.
12934 @node Invoking guix copy
12935 @section Invoking @command{guix copy}
12937 @cindex copy, of store items, over SSH
12938 @cindex SSH, copy of store items
12939 @cindex sharing store items across machines
12940 @cindex transferring store items across machines
12941 The @command{guix copy} command copies items from the store of one
12942 machine to that of another machine over a secure shell (SSH)
12943 connection@footnote{This command is available only when Guile-SSH was
12944 found. @xref{Requirements}, for details.}. For example, the following
12945 command copies the @code{coreutils} package, the user's profile, and all
12946 their dependencies over to @var{host}, logged in as @var{user}:
12949 guix copy --to=@var{user}@@@var{host} \
12950 coreutils `readlink -f ~/.guix-profile`
12953 If some of the items to be copied are already present on @var{host},
12954 they are not actually sent.
12956 The command below retrieves @code{libreoffice} and @code{gimp} from
12957 @var{host}, assuming they are available there:
12960 guix copy --from=@var{host} libreoffice gimp
12963 The SSH connection is established using the Guile-SSH client, which is
12964 compatible with OpenSSH: it honors @file{~/.ssh/known_hosts} and
12965 @file{~/.ssh/config}, and uses the SSH agent for authentication.
12967 The key used to sign items that are sent must be accepted by the remote
12968 machine. Likewise, the key used by the remote machine to sign items you
12969 are retrieving must be in @file{/etc/guix/acl} so it is accepted by your
12970 own daemon. @xref{Invoking guix archive}, for more information about
12971 store item authentication.
12973 The general syntax is:
12976 guix copy [--to=@var{spec}|--from=@var{spec}] @var{items}@dots{}
12979 You must always specify one of the following options:
12982 @item --to=@var{spec}
12983 @itemx --from=@var{spec}
12984 Specify the host to send to or receive from. @var{spec} must be an SSH
12985 spec such as @code{example.org}, @code{charlie@@example.org}, or
12986 @code{charlie@@example.org:2222}.
12989 The @var{items} can be either package names, such as @code{gimp}, or
12990 store items, such as @file{/gnu/store/@dots{}-idutils-4.6}.
12992 When specifying the name of a package to send, it is first built if
12993 needed, unless @option{--dry-run} was specified. Common build options
12994 are supported (@pxref{Common Build Options}).
12997 @node Invoking guix container
12998 @section Invoking @command{guix container}
13000 @cindex @command{guix container}
13002 As of version @value{VERSION}, this tool is experimental. The interface
13003 is subject to radical change in the future.
13006 The purpose of @command{guix container} is to manipulate processes
13007 running within an isolated environment, commonly known as a
13008 ``container'', typically created by the @command{guix environment}
13009 (@pxref{Invoking guix environment}) and @command{guix system container}
13010 (@pxref{Invoking guix system}) commands.
13012 The general syntax is:
13015 guix container @var{action} @var{options}@dots{}
13018 @var{action} specifies the operation to perform with a container, and
13019 @var{options} specifies the context-specific arguments for the action.
13021 The following actions are available:
13025 Execute a command within the context of a running container.
13030 guix container exec @var{pid} @var{program} @var{arguments}@dots{}
13033 @var{pid} specifies the process ID of the running container.
13034 @var{program} specifies an executable file name within the root file
13035 system of the container. @var{arguments} are the additional options that
13036 will be passed to @var{program}.
13038 The following command launches an interactive login shell inside a
13039 Guix system container, started by @command{guix system container}, and whose
13040 process ID is 9001:
13043 guix container exec 9001 /run/current-system/profile/bin/bash --login
13046 Note that the @var{pid} cannot be the parent process of a container. It
13047 must be PID 1 of the container or one of its child processes.
13051 @node Invoking guix weather
13052 @section Invoking @command{guix weather}
13054 Occasionally you're grumpy because substitutes are lacking and you end
13055 up building packages by yourself (@pxref{Substitutes}). The
13056 @command{guix weather} command reports on substitute availability on the
13057 specified servers so you can have an idea of whether you'll be grumpy
13058 today. It can sometimes be useful info as a user, but it is primarily
13059 useful to people running @command{guix publish} (@pxref{Invoking guix
13062 @cindex statistics, for substitutes
13063 @cindex availability of substitutes
13064 @cindex substitute availability
13065 @cindex weather, substitute availability
13066 Here's a sample run:
13069 $ guix weather --substitute-urls=https://guix.example.org
13070 computing 5,872 package derivations for x86_64-linux...
13071 looking for 6,128 store items on https://guix.example.org..
13072 updating list of substitutes from 'https://guix.example.org'... 100.0%
13073 https://guix.example.org
13074 43.4% substitutes available (2,658 out of 6,128)
13075 7,032.5 MiB of nars (compressed)
13076 19,824.2 MiB on disk (uncompressed)
13077 0.030 seconds per request (182.9 seconds in total)
13078 33.5 requests per second
13080 9.8% (342 out of 3,470) of the missing items are queued
13082 x86_64-linux: 518 (59.7%)
13083 i686-linux: 221 (25.5%)
13084 aarch64-linux: 128 (14.8%)
13085 build rate: 23.41 builds per hour
13086 x86_64-linux: 11.16 builds per hour
13087 i686-linux: 6.03 builds per hour
13088 aarch64-linux: 6.41 builds per hour
13091 @cindex continuous integration, statistics
13092 As you can see, it reports the fraction of all the packages for which
13093 substitutes are available on the server---regardless of whether
13094 substitutes are enabled, and regardless of whether this server's signing
13095 key is authorized. It also reports the size of the compressed archives
13096 (``nars'') provided by the server, the size the corresponding store
13097 items occupy in the store (assuming deduplication is turned off), and
13098 the server's throughput. The second part gives continuous integration
13099 (CI) statistics, if the server supports it. In addition, using the
13100 @option{--coverage} option, @command{guix weather} can list ``important''
13101 package substitutes missing on the server (see below).
13103 To achieve that, @command{guix weather} queries over HTTP(S) meta-data
13104 (@dfn{narinfos}) for all the relevant store items. Like @command{guix
13105 challenge}, it ignores signatures on those substitutes, which is
13106 innocuous since the command only gathers statistics and cannot install
13109 The general syntax is:
13112 guix weather @var{options}@dots{} [@var{packages}@dots{}]
13115 When @var{packages} is omitted, @command{guix weather} checks the availability
13116 of substitutes for @emph{all} the packages, or for those specified with
13117 @option{--manifest}; otherwise it only considers the specified packages. It
13118 is also possible to query specific system types with @option{--system}.
13119 @command{guix weather} exits with a non-zero code when the fraction of
13120 available substitutes is below 100%.
13122 The available options are listed below.
13125 @item --substitute-urls=@var{urls}
13126 @var{urls} is the space-separated list of substitute server URLs to
13127 query. When this option is omitted, the default set of substitute
13128 servers is queried.
13130 @item --system=@var{system}
13131 @itemx -s @var{system}
13132 Query substitutes for @var{system}---e.g., @code{aarch64-linux}. This
13133 option can be repeated, in which case @command{guix weather} will query
13134 substitutes for several system types.
13136 @item --manifest=@var{file}
13137 Instead of querying substitutes for all the packages, only ask for those
13138 specified in @var{file}. @var{file} must contain a @dfn{manifest}, as
13139 with the @code{-m} option of @command{guix package} (@pxref{Invoking
13142 This option can be repeated several times, in which case the manifests
13145 @item --coverage[=@var{count}]
13146 @itemx -c [@var{count}]
13147 Report on substitute coverage for packages: list packages with at least
13148 @var{count} dependents (zero by default) for which substitutes are
13149 unavailable. Dependent packages themselves are not listed: if @var{b} depends
13150 on @var{a} and @var{a} has no substitutes, only @var{a} is listed, even though
13151 @var{b} usually lacks substitutes as well. The result looks like this:
13154 $ guix weather --substitute-urls=@value{SUBSTITUTE-URL} -c 10
13155 computing 8,983 package derivations for x86_64-linux...
13156 looking for 9,343 store items on @value{SUBSTITUTE-URL}...
13157 updating substitutes from '@value{SUBSTITUTE-URL}'... 100.0%
13158 @value{SUBSTITUTE-URL}
13159 64.7% substitutes available (6,047 out of 9,343)
13161 2502 packages are missing from '@value{SUBSTITUTE-URL}' for 'x86_64-linux', among which:
13162 58 kcoreaddons@@5.49.0 /gnu/store/@dots{}-kcoreaddons-5.49.0
13163 46 qgpgme@@1.11.1 /gnu/store/@dots{}-qgpgme-1.11.1
13164 37 perl-http-cookiejar@@0.008 /gnu/store/@dots{}-perl-http-cookiejar-0.008
13168 What this example shows is that @code{kcoreaddons} and presumably the 58
13169 packages that depend on it have no substitutes at
13170 @code{@value{SUBSTITUTE-SERVER}}; likewise for @code{qgpgme} and the 46
13171 packages that depend on it.
13173 If you are a Guix developer, or if you are taking care of this build farm,
13174 you'll probably want to have a closer look at these packages: they may simply
13177 @item --display-missing
13178 Display the list of store items for which substitutes are missing.
13181 @node Invoking guix processes
13182 @section Invoking @command{guix processes}
13184 The @command{guix processes} command can be useful to developers and system
13185 administrators, especially on multi-user machines and on build farms: it lists
13186 the current sessions (connections to the daemon), as well as information about
13187 the processes involved@footnote{Remote sessions, when @command{guix-daemon} is
13188 started with @option{--listen} specifying a TCP endpoint, are @emph{not}
13189 listed.}. Here's an example of the information it returns:
13192 $ sudo guix processes
13195 ClientCommand: guix environment --ad-hoc python
13199 ClientCommand: guix publish -u guix-publish -p 3000 -C 9 @dots{}
13203 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
13204 LockHeld: /gnu/store/@dots{}-perl-ipc-cmd-0.96.lock
13205 LockHeld: /gnu/store/@dots{}-python-six-bootstrap-1.11.0.lock
13206 LockHeld: /gnu/store/@dots{}-libjpeg-turbo-2.0.0.lock
13208 ChildCommand: guix offload x86_64-linux 7200 1 28800
13210 ChildCommand: guix offload x86_64-linux 7200 1 28800
13212 ChildCommand: guix offload x86_64-linux 7200 1 28800
13215 In this example we see that @command{guix-daemon} has three clients:
13216 @command{guix environment}, @command{guix publish}, and the Cuirass continuous
13217 integration tool; their process identifier (PID) is given by the
13218 @code{ClientPID} field. The @code{SessionPID} field gives the PID of the
13219 @command{guix-daemon} sub-process of this particular session.
13221 The @code{LockHeld} fields show which store items are currently locked
13222 by this session, which corresponds to store items being built or
13223 substituted (the @code{LockHeld} field is not displayed when
13224 @command{guix processes} is not running as root). Last, by looking at
13225 the @code{ChildPID} and @code{ChildCommand} fields, we understand that
13226 these three builds are being offloaded (@pxref{Daemon Offload Setup}).
13228 The output is in Recutils format so we can use the handy @command{recsel}
13229 command to select sessions of interest (@pxref{Selection Expressions,,,
13230 recutils, GNU recutils manual}). As an example, the command shows the command
13231 line and PID of the client that triggered the build of a Perl package:
13234 $ sudo guix processes | \
13235 recsel -p ClientPID,ClientCommand -e 'LockHeld ~ "perl"'
13237 ClientCommand: cuirass --cache-directory /var/cache/cuirass @dots{}
13240 Additional options are listed below.
13243 @item --format=@var{format}
13244 @itemx -f @var{format}
13245 Produce output in the specified @var{format}, one of:
13249 The default option. It outputs a set of Session recutils records
13250 that include each @code{ChildProcess} as a field.
13253 Normalize the output records into record sets (@pxref{Record Sets,,,
13254 recutils, GNU recutils manual}). Normalizing into record sets allows
13255 joins across record types. The example below lists the PID of each
13256 @code{ChildProcess} and the associated PID for @code{Session} that
13257 spawned the @code{ChildProcess} where the @code{Session} was started
13258 using @command{guix build}.
13261 $ guix processes --format=normalized | \
13265 -p Session.PID,PID \
13266 -e 'Session.ClientCommand ~ "guix build"'
13279 @node System Configuration
13280 @chapter System Configuration
13282 @cindex system configuration
13283 Guix System supports a consistent whole-system configuration
13284 mechanism. By that we mean that all aspects of the global system
13285 configuration---such as the available system services, timezone and
13286 locale settings, user accounts---are declared in a single place. Such
13287 a @dfn{system configuration} can be @dfn{instantiated}---i.e., effected.
13289 One of the advantages of putting all the system configuration under the
13290 control of Guix is that it supports transactional system upgrades, and
13291 makes it possible to roll back to a previous system instantiation,
13292 should something go wrong with the new one (@pxref{Features}). Another
13293 advantage is that it makes it easy to replicate the exact same configuration
13294 across different machines, or at different points in time, without
13295 having to resort to additional administration tools layered on top of
13296 the own tools of the system.
13297 @c Yes, we're talking of Puppet, Chef, & co. here. ↑
13299 This section describes this mechanism. First we focus on the system
13300 administrator's viewpoint---explaining how the system is configured and
13301 instantiated. Then we show how this mechanism can be extended, for
13302 instance to support new system services.
13305 * Using the Configuration System:: Customizing your GNU system.
13306 * operating-system Reference:: Detail of operating-system declarations.
13307 * File Systems:: Configuring file system mounts.
13308 * Mapped Devices:: Block device extra processing.
13309 * User Accounts:: Specifying user accounts.
13310 * Keyboard Layout:: How the system interprets key strokes.
13311 * Locales:: Language and cultural convention settings.
13312 * Services:: Specifying system services.
13313 * Setuid Programs:: Programs running with root privileges.
13314 * X.509 Certificates:: Authenticating HTTPS servers.
13315 * Name Service Switch:: Configuring libc's name service switch.
13316 * Initial RAM Disk:: Linux-Libre bootstrapping.
13317 * Bootloader Configuration:: Configuring the boot loader.
13318 * Invoking guix system:: Instantiating a system configuration.
13319 * Invoking guix deploy:: Deploying a system configuration to a remote host.
13320 * Running Guix in a VM:: How to run Guix System in a virtual machine.
13321 * Defining Services:: Adding new service definitions.
13324 @node Using the Configuration System
13325 @section Using the Configuration System
13327 The operating system is configured by providing an
13328 @code{operating-system} declaration in a file that can then be passed to
13329 the @command{guix system} command (@pxref{Invoking guix system}). A
13330 simple setup, with the default system services, the default Linux-Libre
13331 kernel, initial RAM disk, and boot loader looks like this:
13333 @findex operating-system
13335 @include os-config-bare-bones.texi
13338 This example should be self-describing. Some of the fields defined
13339 above, such as @code{host-name} and @code{bootloader}, are mandatory.
13340 Others, such as @code{packages} and @code{services}, can be omitted, in
13341 which case they get a default value.
13343 Below we discuss the effect of some of the most important fields
13344 (@pxref{operating-system Reference}, for details about all the available
13345 fields), and how to @dfn{instantiate} the operating system using
13346 @command{guix system}.
13348 @unnumberedsubsec Bootloader
13350 @cindex legacy boot, on Intel machines
13351 @cindex BIOS boot, on Intel machines
13354 The @code{bootloader} field describes the method that will be used to boot
13355 your system. Machines based on Intel processors can boot in ``legacy'' BIOS
13356 mode, as in the example above. However, more recent machines rely instead on
13357 the @dfn{Unified Extensible Firmware Interface} (UEFI) to boot. In that case,
13358 the @code{bootloader} field should contain something along these lines:
13361 (bootloader-configuration
13362 (bootloader grub-efi-bootloader)
13363 (target "/boot/efi"))
13366 @xref{Bootloader Configuration}, for more information on the available
13367 configuration options.
13369 @unnumberedsubsec Globally-Visible Packages
13371 @vindex %base-packages
13372 The @code{packages} field lists packages that will be globally visible
13373 on the system, for all user accounts---i.e., in every user's @env{PATH}
13374 environment variable---in addition to the per-user profiles
13375 (@pxref{Invoking guix package}). The @code{%base-packages} variable
13376 provides all the tools one would expect for basic user and administrator
13377 tasks---including the GNU Core Utilities, the GNU Networking Utilities,
13378 the GNU Zile lightweight text editor, @command{find}, @command{grep},
13379 etc. The example above adds GNU@tie{}Screen to those,
13380 taken from the @code{(gnu packages screen)}
13381 module (@pxref{Package Modules}). The
13382 @code{(list package output)} syntax can be used to add a specific output
13386 (use-modules (gnu packages))
13387 (use-modules (gnu packages dns))
13391 (packages (cons (list bind "utils")
13395 @findex specification->package
13396 Referring to packages by variable name, like @code{bind} above, has
13397 the advantage of being unambiguous; it also allows typos and such to be
13398 diagnosed right away as ``unbound variables''. The downside is that one
13399 needs to know which module defines which package, and to augment the
13400 @code{use-package-modules} line accordingly. To avoid that, one can use
13401 the @code{specification->package} procedure of the @code{(gnu packages)}
13402 module, which returns the best package for a given name or name and
13406 (use-modules (gnu packages))
13410 (packages (append (map specification->package
13411 '("tcpdump" "htop" "gnupg@@2.0"))
13415 @unnumberedsubsec System Services
13418 @vindex %base-services
13419 The @code{services} field lists @dfn{system services} to be made
13420 available when the system starts (@pxref{Services}).
13421 The @code{operating-system} declaration above specifies that, in
13422 addition to the basic services, we want the OpenSSH secure shell
13423 daemon listening on port 2222 (@pxref{Networking Services,
13424 @code{openssh-service-type}}). Under the hood,
13425 @code{openssh-service-type} arranges so that @command{sshd} is started with the
13426 right command-line options, possibly with supporting configuration files
13427 generated as needed (@pxref{Defining Services}).
13429 @cindex customization, of services
13430 @findex modify-services
13431 Occasionally, instead of using the base services as is, you will want to
13432 customize them. To do this, use @code{modify-services} (@pxref{Service
13433 Reference, @code{modify-services}}) to modify the list.
13435 For example, suppose you want to modify @code{guix-daemon} and Mingetty
13436 (the console log-in) in the @code{%base-services} list (@pxref{Base
13437 Services, @code{%base-services}}). To do that, you can write the
13438 following in your operating system declaration:
13441 (define %my-services
13442 ;; My very own list of services.
13443 (modify-services %base-services
13444 (guix-service-type config =>
13445 (guix-configuration
13447 ;; Fetch substitutes from example.org.
13449 (list "https://example.org/guix"
13450 "https://ci.guix.gnu.org"))))
13451 (mingetty-service-type config =>
13452 (mingetty-configuration
13454 ;; Automatially log in as "guest".
13455 (auto-login "guest")))))
13459 (services %my-services))
13462 This changes the configuration---i.e., the service parameters---of the
13463 @code{guix-service-type} instance, and that of all the
13464 @code{mingetty-service-type} instances in the @code{%base-services} list.
13465 Observe how this is accomplished: first, we arrange for the original
13466 configuration to be bound to the identifier @code{config} in the
13467 @var{body}, and then we write the @var{body} so that it evaluates to the
13468 desired configuration. In particular, notice how we use @code{inherit}
13469 to create a new configuration which has the same values as the old
13470 configuration, but with a few modifications.
13472 @cindex encrypted disk
13473 The configuration for a typical ``desktop'' usage, with an encrypted
13474 root partition, the X11 display
13475 server, GNOME and Xfce (users can choose which of these desktop
13476 environments to use at the log-in screen by pressing @kbd{F1}), network
13477 management, power management, and more, would look like this:
13480 @include os-config-desktop.texi
13483 A graphical system with a choice of lightweight window managers
13484 instead of full-blown desktop environments would look like this:
13487 @include os-config-lightweight-desktop.texi
13490 This example refers to the @file{/boot/efi} file system by its UUID,
13491 @code{1234-ABCD}. Replace this UUID with the right UUID on your system,
13492 as returned by the @command{blkid} command.
13494 @xref{Desktop Services}, for the exact list of services provided by
13495 @code{%desktop-services}. @xref{X.509 Certificates}, for background
13496 information about the @code{nss-certs} package that is used here.
13498 Again, @code{%desktop-services} is just a list of service objects. If
13499 you want to remove services from there, you can do so using the
13500 procedures for list filtering (@pxref{SRFI-1 Filtering and
13501 Partitioning,,, guile, GNU Guile Reference Manual}). For instance, the
13502 following expression returns a list that contains all the services in
13503 @code{%desktop-services} minus the Avahi service:
13506 (remove (lambda (service)
13507 (eq? (service-kind service) avahi-service-type))
13511 @unnumberedsubsec Instantiating the System
13513 Assuming the @code{operating-system} declaration
13514 is stored in the @file{my-system-config.scm}
13515 file, the @command{guix system reconfigure my-system-config.scm} command
13516 instantiates that configuration, and makes it the default GRUB boot
13517 entry (@pxref{Invoking guix system}).
13519 The normal way to change the system configuration is by updating this
13520 file and re-running @command{guix system reconfigure}. One should never
13521 have to touch files in @file{/etc} or to run commands that modify the
13522 system state such as @command{useradd} or @command{grub-install}. In
13523 fact, you must avoid that since that would not only void your warranty
13524 but also prevent you from rolling back to previous versions of your
13525 system, should you ever need to.
13527 @cindex roll-back, of the operating system
13528 Speaking of roll-back, each time you run @command{guix system
13529 reconfigure}, a new @dfn{generation} of the system is created---without
13530 modifying or deleting previous generations. Old system generations get
13531 an entry in the bootloader boot menu, allowing you to boot them in case
13532 something went wrong with the latest generation. Reassuring, no? The
13533 @command{guix system list-generations} command lists the system
13534 generations available on disk. It is also possible to roll back the
13535 system via the commands @command{guix system roll-back} and
13536 @command{guix system switch-generation}.
13538 Although the @command{guix system reconfigure} command will not modify
13539 previous generations, you must take care when the current generation is not
13540 the latest (e.g., after invoking @command{guix system roll-back}), since
13541 the operation might overwrite a later generation (@pxref{Invoking guix
13544 @unnumberedsubsec The Programming Interface
13546 At the Scheme level, the bulk of an @code{operating-system} declaration
13547 is instantiated with the following monadic procedure (@pxref{The Store
13550 @deffn {Monadic Procedure} operating-system-derivation os
13551 Return a derivation that builds @var{os}, an @code{operating-system}
13552 object (@pxref{Derivations}).
13554 The output of the derivation is a single directory that refers to all
13555 the packages, configuration files, and other supporting files needed to
13556 instantiate @var{os}.
13559 This procedure is provided by the @code{(gnu system)} module. Along
13560 with @code{(gnu services)} (@pxref{Services}), this module contains the
13561 guts of Guix System. Make sure to visit it!
13564 @node operating-system Reference
13565 @section @code{operating-system} Reference
13567 This section summarizes all the options available in
13568 @code{operating-system} declarations (@pxref{Using the Configuration
13571 @deftp {Data Type} operating-system
13572 This is the data type representing an operating system configuration.
13573 By that, we mean all the global system configuration, not per-user
13574 configuration (@pxref{Using the Configuration System}).
13577 @item @code{kernel} (default: @code{linux-libre})
13578 The package object of the operating system kernel to
13579 use@footnote{Currently only the Linux-libre kernel is fully supported.
13580 Using GNU@tie{}mach with the GNU@tie{}Hurd is experimental and only
13581 available when building a virtual machine disk image.}.
13584 @item @code{hurd} (default: @code{#f})
13585 The package object of the Hurd to be started by the kernel. When this
13586 field is set, produce a GNU/Hurd operating system. In that case,
13587 @code{kernel} must also be set to the @code{gnumach} package---the
13588 microkernel the Hurd runs on.
13591 This feature is experimental and only supported for disk images.
13594 @item @code{kernel-loadable-modules} (default: '())
13595 A list of objects (usually packages) to collect loadable kernel modules
13596 from--e.g. @code{(list ddcci-driver-linux)}.
13598 @item @code{kernel-arguments} (default: @code{%default-kernel-arguments})
13599 List of strings or gexps representing additional arguments to pass on
13600 the command-line of the kernel---e.g., @code{("console=ttyS0")}.
13602 @item @code{bootloader}
13603 The system bootloader configuration object. @xref{Bootloader Configuration}.
13606 This is the label (a string) as it appears in the bootloader's menu entry.
13607 The default label includes the kernel name and version.
13609 @item @code{keyboard-layout} (default: @code{#f})
13610 This field specifies the keyboard layout to use in the console. It can be
13611 either @code{#f}, in which case the default keyboard layout is used (usually
13612 US English), or a @code{<keyboard-layout>} record. @xref{Keyboard Layout},
13613 for more information.
13615 This keyboard layout is in effect as soon as the kernel has booted. For
13616 instance, it is the keyboard layout in effect when you type a passphrase if
13617 your root file system is on a @code{luks-device-mapping} mapped device
13618 (@pxref{Mapped Devices}).
13621 This does @emph{not} specify the keyboard layout used by the bootloader, nor
13622 that used by the graphical display server. @xref{Bootloader Configuration},
13623 for information on how to specify the bootloader's keyboard layout. @xref{X
13624 Window}, for information on how to specify the keyboard layout used by the X
13628 @item @code{initrd-modules} (default: @code{%base-initrd-modules})
13630 @cindex initial RAM disk
13631 The list of Linux kernel modules that need to be available in the
13632 initial RAM disk. @xref{Initial RAM Disk}.
13634 @item @code{initrd} (default: @code{base-initrd})
13635 A procedure that returns an initial RAM disk for the Linux
13636 kernel. This field is provided to support low-level customization and
13637 should rarely be needed for casual use. @xref{Initial RAM Disk}.
13639 @item @code{firmware} (default: @code{%base-firmware})
13641 List of firmware packages loadable by the operating system kernel.
13643 The default includes firmware needed for Atheros- and Broadcom-based
13644 WiFi devices (Linux-libre modules @code{ath9k} and @code{b43-open},
13645 respectively). @xref{Hardware Considerations}, for more info on
13646 supported hardware.
13648 @item @code{host-name}
13651 @item @code{hosts-file}
13653 A file-like object (@pxref{G-Expressions, file-like objects}) for use as
13654 @file{/etc/hosts} (@pxref{Host Names,,, libc, The GNU C Library
13655 Reference Manual}). The default is a file with entries for
13656 @code{localhost} and @var{host-name}.
13658 @item @code{mapped-devices} (default: @code{'()})
13659 A list of mapped devices. @xref{Mapped Devices}.
13661 @item @code{file-systems}
13662 A list of file systems. @xref{File Systems}.
13664 @cindex swap devices
13666 @item @code{swap-devices} (default: @code{'()})
13667 A list of UUIDs, file system labels, or strings identifying devices or
13668 files to be used for ``swap
13669 space'' (@pxref{Memory Concepts,,, libc, The GNU C Library Reference
13670 Manual}). Here are some examples:
13673 @item (list (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb"))
13674 Use the swap partition with the given UUID@. You can learn the UUID of a
13675 Linux swap partition by running @command{swaplabel @var{device}}, where
13676 @var{device} is the @file{/dev} file name of that partition.
13678 @item (list (file-system-label "swap"))
13679 Use the partition with label @code{swap}. Again, the
13680 @command{swaplabel} command allows you to view and change the label of a
13681 Linux swap partition.
13683 @item (list "/swapfile")
13684 Use the file @file{/swapfile} as swap space.
13686 @item (list "/dev/sda3" "/dev/sdb2")
13687 Use the @file{/dev/sda3} and @file{/dev/sdb2} partitions as swap space.
13688 We recommend referring to swap devices by UUIDs or labels as shown above
13692 It is possible to specify a swap file in a file system on a mapped
13693 device (under @file{/dev/mapper}), provided that the necessary device
13694 mapping and file system are also specified. @xref{Mapped Devices} and
13695 @ref{File Systems}.
13697 @item @code{users} (default: @code{%base-user-accounts})
13698 @itemx @code{groups} (default: @code{%base-groups})
13699 List of user accounts and groups. @xref{User Accounts}.
13701 If the @code{users} list lacks a user account with UID@tie{}0, a
13702 ``root'' account with UID@tie{}0 is automatically added.
13704 @item @code{skeletons} (default: @code{(default-skeletons)})
13705 A list of target file name/file-like object tuples (@pxref{G-Expressions,
13706 file-like objects}). These are the skeleton files that will be added to
13707 the home directory of newly-created user accounts.
13709 For instance, a valid value may look like this:
13712 `((".bashrc" ,(plain-file "bashrc" "echo Hello\n"))
13713 (".guile" ,(plain-file "guile"
13714 "(use-modules (ice-9 readline))
13715 (activate-readline)")))
13718 @item @code{issue} (default: @code{%default-issue})
13719 A string denoting the contents of the @file{/etc/issue} file, which is
13720 displayed when users log in on a text console.
13722 @item @code{packages} (default: @code{%base-packages})
13723 A list of packages to be installed in the global profile, which is accessible
13724 at @file{/run/current-system/profile}. Each element is either a package
13725 variable or a package/output tuple. Here's a simple example of both:
13728 (cons* git ; the default "out" output
13729 (list git "send-email") ; another output of git
13730 %base-packages) ; the default set
13733 The default set includes core utilities and it is good practice to
13734 install non-core utilities in user profiles (@pxref{Invoking guix
13737 @item @code{timezone}
13738 A timezone identifying string---e.g., @code{"Europe/Paris"}.
13740 You can run the @command{tzselect} command to find out which timezone
13741 string corresponds to your region. Choosing an invalid timezone name
13742 causes @command{guix system} to fail.
13744 @item @code{locale} (default: @code{"en_US.utf8"})
13745 The name of the default locale (@pxref{Locale Names,,, libc, The GNU C
13746 Library Reference Manual}). @xref{Locales}, for more information.
13748 @item @code{locale-definitions} (default: @code{%default-locale-definitions})
13749 The list of locale definitions to be compiled and that may be used at
13750 run time. @xref{Locales}.
13752 @item @code{locale-libcs} (default: @code{(list @var{glibc})})
13753 The list of GNU@tie{}libc packages whose locale data and tools are used
13754 to build the locale definitions. @xref{Locales}, for compatibility
13755 considerations that justify this option.
13757 @item @code{name-service-switch} (default: @code{%default-nss})
13758 Configuration of the libc name service switch (NSS)---a
13759 @code{<name-service-switch>} object. @xref{Name Service Switch}, for
13762 @item @code{services} (default: @code{%base-services})
13763 A list of service objects denoting system services. @xref{Services}.
13765 @cindex essential services
13766 @item @code{essential-services} (default: ...)
13767 The list of ``essential services''---i.e., things like instances of
13768 @code{system-service-type} and @code{host-name-service-type} (@pxref{Service
13769 Reference}), which are derived from the operating system definition itself.
13770 As a user you should @emph{never} need to touch this field.
13772 @item @code{pam-services} (default: @code{(base-pam-services)})
13774 @cindex pluggable authentication modules
13775 Linux @dfn{pluggable authentication module} (PAM) services.
13776 @c FIXME: Add xref to PAM services section.
13778 @item @code{setuid-programs} (default: @code{%setuid-programs})
13779 List of string-valued G-expressions denoting setuid programs.
13780 @xref{Setuid Programs}.
13782 @item @code{sudoers-file} (default: @code{%sudoers-specification})
13783 @cindex sudoers file
13784 The contents of the @file{/etc/sudoers} file as a file-like object
13785 (@pxref{G-Expressions, @code{local-file} and @code{plain-file}}).
13787 This file specifies which users can use the @command{sudo} command, what
13788 they are allowed to do, and what privileges they may gain. The default
13789 is that only @code{root} and members of the @code{wheel} group may use
13794 @deffn {Scheme Syntax} this-operating-system
13795 When used in the @emph{lexical scope} of an operating system field definition,
13796 this identifier resolves to the operating system being defined.
13798 The example below shows how to refer to the operating system being defined in
13799 the definition of the @code{label} field:
13802 (use-modules (gnu) (guix))
13806 (label (package-full-name
13807 (operating-system-kernel this-operating-system))))
13810 It is an error to refer to @code{this-operating-system} outside an operating
13817 @section File Systems
13819 The list of file systems to be mounted is specified in the
13820 @code{file-systems} field of the operating system declaration
13821 (@pxref{Using the Configuration System}). Each file system is declared
13822 using the @code{file-system} form, like this:
13826 (mount-point "/home")
13827 (device "/dev/sda3")
13831 As usual, some of the fields are mandatory---those shown in the example
13832 above---while others can be omitted. These are described below.
13834 @deftp {Data Type} file-system
13835 Objects of this type represent file systems to be mounted. They
13836 contain the following members:
13840 This is a string specifying the type of the file system---e.g.,
13843 @item @code{mount-point}
13844 This designates the place where the file system is to be mounted.
13846 @item @code{device}
13847 This names the ``source'' of the file system. It can be one of three
13848 things: a file system label, a file system UUID, or the name of a
13849 @file{/dev} node. Labels and UUIDs offer a way to refer to file
13850 systems without having to hard-code their actual device
13851 name@footnote{Note that, while it is tempting to use
13852 @file{/dev/disk/by-uuid} and similar device names to achieve the same
13853 result, this is not recommended: These special device nodes are created
13854 by the udev daemon and may be unavailable at the time the device is
13857 @findex file-system-label
13858 File system labels are created using the @code{file-system-label}
13859 procedure, UUIDs are created using @code{uuid}, and @file{/dev} node are
13860 plain strings. Here's an example of a file system referred to by its
13861 label, as shown by the @command{e2label} command:
13865 (mount-point "/home")
13867 (device (file-system-label "my-home")))
13871 UUIDs are converted from their string representation (as shown by the
13872 @command{tune2fs -l} command) using the @code{uuid} form@footnote{The
13873 @code{uuid} form expects 16-byte UUIDs as defined in
13874 @uref{https://tools.ietf.org/html/rfc4122, RFC@tie{}4122}. This is the
13875 form of UUID used by the ext2 family of file systems and others, but it
13876 is different from ``UUIDs'' found in FAT file systems, for instance.},
13881 (mount-point "/home")
13883 (device (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")))
13886 When the source of a file system is a mapped device (@pxref{Mapped
13887 Devices}), its @code{device} field @emph{must} refer to the mapped
13888 device name---e.g., @file{"/dev/mapper/root-partition"}.
13889 This is required so that
13890 the system knows that mounting the file system depends on having the
13891 corresponding device mapping established.
13893 @item @code{flags} (default: @code{'()})
13894 This is a list of symbols denoting mount flags. Recognized flags
13895 include @code{read-only}, @code{bind-mount}, @code{no-dev} (disallow
13896 access to special files), @code{no-suid} (ignore setuid and setgid
13897 bits), @code{no-atime} (do not update file access times),
13898 @code{strict-atime} (update file access time), @code{lazy-time} (only
13899 update time on the in-memory version of the file inode), and
13900 @code{no-exec} (disallow program execution).
13901 @xref{Mount-Unmount-Remount,,, libc, The GNU C Library Reference
13902 Manual}, for more information on these flags.
13904 @item @code{options} (default: @code{#f})
13905 This is either @code{#f}, or a string denoting mount options passed to
13906 the file system driver. @xref{Mount-Unmount-Remount,,, libc, The GNU C
13907 Library Reference Manual}, for details and run @command{man 8 mount} for
13908 options for various file systems. Note that the
13909 @code{file-system-options->alist} and @code{alist->file-system-options}
13910 procedures from @code{(gnu system file-systems)} can be used to convert
13911 file system options given as an association list to the string
13912 representation, and vice-versa.
13914 @item @code{mount?} (default: @code{#t})
13915 This value indicates whether to automatically mount the file system when
13916 the system is brought up. When set to @code{#f}, the file system gets
13917 an entry in @file{/etc/fstab} (read by the @command{mount} command) but
13918 is not automatically mounted.
13920 @item @code{needed-for-boot?} (default: @code{#f})
13921 This Boolean value indicates whether the file system is needed when
13922 booting. If that is true, then the file system is mounted when the
13923 initial RAM disk (initrd) is loaded. This is always the case, for
13924 instance, for the root file system.
13926 @item @code{check?} (default: @code{#t})
13927 This Boolean indicates whether the file system needs to be checked for
13928 errors before being mounted.
13930 @item @code{create-mount-point?} (default: @code{#f})
13931 When true, the mount point is created if it does not exist yet.
13933 @item @code{mount-may-fail?} (default: @code{#f})
13934 When true, this indicates that mounting this file system can fail but
13935 that should not be considered an error. This is useful in unusual
13936 cases; an example of this is @code{efivarfs}, a file system that can
13937 only be mounted on EFI/UEFI systems.
13939 @item @code{dependencies} (default: @code{'()})
13940 This is a list of @code{<file-system>} or @code{<mapped-device>} objects
13941 representing file systems that must be mounted or mapped devices that
13942 must be opened before (and unmounted or closed after) this one.
13944 As an example, consider a hierarchy of mounts: @file{/sys/fs/cgroup} is
13945 a dependency of @file{/sys/fs/cgroup/cpu} and
13946 @file{/sys/fs/cgroup/memory}.
13948 Another example is a file system that depends on a mapped device, for
13949 example for an encrypted partition (@pxref{Mapped Devices}).
13953 @deffn {Scheme Procedure} file-system-label @var{str}
13954 This procedure returns an opaque file system label from @var{str}, a
13958 (file-system-label "home")
13959 @result{} #<file-system-label "home">
13962 File system labels are used to refer to file systems by label rather
13963 than by device name. See above for examples.
13966 The @code{(gnu system file-systems)} exports the following useful
13969 @defvr {Scheme Variable} %base-file-systems
13970 These are essential file systems that are required on normal systems,
13971 such as @code{%pseudo-terminal-file-system} and @code{%immutable-store} (see
13972 below). Operating system declarations should always contain at least
13976 @defvr {Scheme Variable} %pseudo-terminal-file-system
13977 This is the file system to be mounted as @file{/dev/pts}. It supports
13978 @dfn{pseudo-terminals} created @i{via} @code{openpty} and similar
13979 functions (@pxref{Pseudo-Terminals,,, libc, The GNU C Library Reference
13980 Manual}). Pseudo-terminals are used by terminal emulators such as
13984 @defvr {Scheme Variable} %shared-memory-file-system
13985 This file system is mounted as @file{/dev/shm} and is used to support
13986 memory sharing across processes (@pxref{Memory-mapped I/O,
13987 @code{shm_open},, libc, The GNU C Library Reference Manual}).
13990 @defvr {Scheme Variable} %immutable-store
13991 This file system performs a read-only ``bind mount'' of
13992 @file{/gnu/store}, making it read-only for all the users including
13993 @code{root}. This prevents against accidental modification by software
13994 running as @code{root} or by system administrators.
13996 The daemon itself is still able to write to the store: it remounts it
13997 read-write in its own ``name space.''
14000 @defvr {Scheme Variable} %binary-format-file-system
14001 The @code{binfmt_misc} file system, which allows handling of arbitrary
14002 executable file types to be delegated to user space. This requires the
14003 @code{binfmt.ko} kernel module to be loaded.
14006 @defvr {Scheme Variable} %fuse-control-file-system
14007 The @code{fusectl} file system, which allows unprivileged users to mount
14008 and unmount user-space FUSE file systems. This requires the
14009 @code{fuse.ko} kernel module to be loaded.
14012 The @code{(gnu system uuid)} module provides tools to deal with file
14013 system ``unique identifiers'' (UUIDs).
14015 @deffn {Scheme Procedure} uuid @var{str} [@var{type}]
14016 Return an opaque UUID (unique identifier) object of the given @var{type}
14017 (a symbol) by parsing @var{str} (a string):
14020 (uuid "4dab5feb-d176-45de-b287-9b0a6e4c01cb")
14021 @result{} #<<uuid> type: dce bv: @dots{}>
14023 (uuid "1234-ABCD" 'fat)
14024 @result{} #<<uuid> type: fat bv: @dots{}>
14027 @var{type} may be one of @code{dce}, @code{iso9660}, @code{fat},
14028 @code{ntfs}, or one of the commonly found synonyms for these.
14030 UUIDs are another way to unambiguously refer to file systems in
14031 operating system configuration. See the examples above.
14035 @node Btrfs file system
14036 @subsection Btrfs file system
14038 The Btrfs has special features, such as subvolumes, that merit being
14039 explained in more details. The following section attempts to cover
14040 basic as well as complex uses of a Btrfs file system with the Guix
14043 In its simplest usage, a Btrfs file system can be described, for
14048 (mount-point "/home")
14050 (device (file-system-label "my-home")))
14053 The example below is more complex, as it makes use of a Btrfs
14054 subvolume, named @code{rootfs}. The parent Btrfs file system is labeled
14055 @code{my-btrfs-pool}, and is located on an encrypted device (hence the
14056 dependency on @code{mapped-devices}):
14060 (device (file-system-label "my-btrfs-pool"))
14063 (options "subvol=rootfs")
14064 (dependencies mapped-devices))
14067 Some bootloaders, for example GRUB, only mount a Btrfs partition at its
14068 top level during the early boot, and rely on their configuration to
14069 refer to the correct subvolume path within that top level. The
14070 bootloaders operating in this way typically produce their configuration
14071 on a running system where the Btrfs partitions are already mounted and
14072 where the subvolume information is readily available. As an example,
14073 @command{grub-mkconfig}, the configuration generator command shipped
14074 with GRUB, reads @file{/proc/self/mountinfo} to determine the top-level
14075 path of a subvolume.
14077 The Guix System produces a bootloader configuration using the operating
14078 system configuration as its sole input; it is therefore necessary to
14079 extract the subvolume name on which @file{/gnu/store} lives (if any)
14080 from that operating system configuration. To better illustrate,
14081 consider a subvolume named 'rootfs' which contains the root file system
14082 data. In such situation, the GRUB bootloader would only see the top
14083 level of the root Btrfs partition, e.g.:
14087 ├── rootfs (subvolume directory)
14088 ├── gnu (normal directory)
14089 ├── store (normal directory)
14093 Thus, the subvolume name must be prepended to the @file{/gnu/store} path
14094 of the kernel, initrd binaries and any other files referred to in the
14095 GRUB configuration that must be found during the early boot.
14097 The next example shows a nested hierarchy of subvolumes and
14102 ├── rootfs (subvolume)
14103 ├── gnu (normal directory)
14104 ├── store (subvolume)
14108 This scenario would work without mounting the 'store' subvolume.
14109 Mounting 'rootfs' is sufficient, since the subvolume name matches its
14110 intended mount point in the file system hierarchy. Alternatively, the
14111 'store' subvolume could be referred to by setting the @code{subvol}
14112 option to either @code{/rootfs/gnu/store} or @code{rootfs/gnu/store}.
14114 Finally, a more contrived example of nested subvolumes:
14118 ├── root-snapshots (subvolume)
14119 ├── root-current (subvolume)
14120 ├── guix-store (subvolume)
14124 Here, the 'guix-store' subvolume doesn't match its intended mount point,
14125 so it is necessary to mount it. The subvolume must be fully specified,
14126 by passing its file name to the @code{subvol} option. To illustrate,
14127 the 'guix-store' subvolume could be mounted on @file{/gnu/store} by using
14128 a file system declaration such as:
14132 (device (file-system-label "btrfs-pool-1"))
14133 (mount-point "/gnu/store")
14135 (options "subvol=root-snapshots/root-current/guix-store,\
14136 compress-force=zstd,space_cache=v2"))
14139 @node Mapped Devices
14140 @section Mapped Devices
14142 @cindex device mapping
14143 @cindex mapped devices
14144 The Linux kernel has a notion of @dfn{device mapping}: a block device,
14145 such as a hard disk partition, can be @dfn{mapped} into another device,
14146 usually in @code{/dev/mapper/},
14147 with additional processing over the data that flows through
14148 it@footnote{Note that the GNU@tie{}Hurd makes no difference between the
14149 concept of a ``mapped device'' and that of a file system: both boil down
14150 to @emph{translating} input/output operations made on a file to
14151 operations on its backing store. Thus, the Hurd implements mapped
14152 devices, like file systems, using the generic @dfn{translator} mechanism
14153 (@pxref{Translators,,, hurd, The GNU Hurd Reference Manual}).}. A
14154 typical example is encryption device mapping: all writes to the mapped
14155 device are encrypted, and all reads are deciphered, transparently.
14156 Guix extends this notion by considering any device or set of devices that
14157 are @dfn{transformed} in some way to create a new device; for instance,
14158 RAID devices are obtained by @dfn{assembling} several other devices, such
14159 as hard disks or partitions, into a new one that behaves as one partition.
14161 Mapped devices are declared using the @code{mapped-device} form,
14162 defined as follows; for examples, see below.
14164 @deftp {Data Type} mapped-device
14165 Objects of this type represent device mappings that will be made when
14166 the system boots up.
14170 This is either a string specifying the name of the block device to be mapped,
14171 such as @code{"/dev/sda3"}, or a list of such strings when several devices
14172 need to be assembled for creating a new one. In case of LVM this is a
14173 string specifying name of the volume group to be mapped.
14176 This string specifies the name of the resulting mapped device. For
14177 kernel mappers such as encrypted devices of type @code{luks-device-mapping},
14178 specifying @code{"my-partition"} leads to the creation of
14179 the @code{"/dev/mapper/my-partition"} device.
14180 For RAID devices of type @code{raid-device-mapping}, the full device name
14181 such as @code{"/dev/md0"} needs to be given.
14182 LVM logical volumes of type @code{lvm-device-mapping} need to
14183 be specified as @code{"VGNAME-LVNAME"}.
14186 This list of strings specifies names of the resulting mapped devices in case
14187 there are several. The format is identical to @var{target}.
14190 This must be a @code{mapped-device-kind} object, which specifies how
14191 @var{source} is mapped to @var{target}.
14195 @defvr {Scheme Variable} luks-device-mapping
14196 This defines LUKS block device encryption using the @command{cryptsetup}
14197 command from the package with the same name. It relies on the
14198 @code{dm-crypt} Linux kernel module.
14201 @defvr {Scheme Variable} raid-device-mapping
14202 This defines a RAID device, which is assembled using the @code{mdadm}
14203 command from the package with the same name. It requires a Linux kernel
14204 module for the appropriate RAID level to be loaded, such as @code{raid456}
14205 for RAID-4, RAID-5 or RAID-6, or @code{raid10} for RAID-10.
14208 @cindex LVM, logical volume manager
14209 @defvr {Scheme Variable} lvm-device-mapping
14210 This defines one or more logical volumes for the Linux
14211 @uref{https://www.sourceware.org/lvm2/, Logical Volume Manager (LVM)}.
14212 The volume group is activated by the @command{vgchange} command from the
14213 @code{lvm2} package.
14216 @cindex disk encryption
14218 The following example specifies a mapping from @file{/dev/sda3} to
14219 @file{/dev/mapper/home} using LUKS---the
14220 @url{https://gitlab.com/cryptsetup/cryptsetup,Linux Unified Key Setup}, a
14221 standard mechanism for disk encryption.
14222 The @file{/dev/mapper/home}
14223 device can then be used as the @code{device} of a @code{file-system}
14224 declaration (@pxref{File Systems}).
14228 (source "/dev/sda3")
14230 (type luks-device-mapping))
14233 Alternatively, to become independent of device numbering, one may obtain
14234 the LUKS UUID (@dfn{unique identifier}) of the source device by a
14238 cryptsetup luksUUID /dev/sda3
14241 and use it as follows:
14245 (source (uuid "cb67fc72-0d54-4c88-9d4b-b225f30b0f44"))
14247 (type luks-device-mapping))
14250 @cindex swap encryption
14251 It is also desirable to encrypt swap space, since swap space may contain
14252 sensitive data. One way to accomplish that is to use a swap file in a
14253 file system on a device mapped via LUKS encryption. In this way, the
14254 swap file is encrypted because the entire device is encrypted.
14255 @xref{Preparing for Installation,,Disk Partitioning}, for an example.
14257 A RAID device formed of the partitions @file{/dev/sda1} and @file{/dev/sdb1}
14258 may be declared as follows:
14262 (source (list "/dev/sda1" "/dev/sdb1"))
14263 (target "/dev/md0")
14264 (type raid-device-mapping))
14267 The @file{/dev/md0} device can then be used as the @code{device} of a
14268 @code{file-system} declaration (@pxref{File Systems}).
14269 Note that the RAID level need not be given; it is chosen during the
14270 initial creation and formatting of the RAID device and is determined
14271 automatically later.
14273 LVM logical volumes ``alpha'' and ``beta'' from volume group ``vg0'' can
14274 be declared as follows:
14279 (targets (list "vg0-alpha" "vg0-beta"))
14280 (type lvm-device-mapping))
14283 Devices @file{/dev/mapper/vg0-alpha} and @file{/dev/mapper/vg0-beta} can
14284 then be used as the @code{device} of a @code{file-system} declaration
14285 (@pxref{File Systems}).
14287 @node User Accounts
14288 @section User Accounts
14292 @cindex user accounts
14293 User accounts and groups are entirely managed through the
14294 @code{operating-system} declaration. They are specified with the
14295 @code{user-account} and @code{user-group} forms:
14301 (supplementary-groups '("wheel" ;allow use of sudo, etc.
14302 "audio" ;sound card
14303 "video" ;video devices such as webcams
14304 "cdrom")) ;the good ol' CD-ROM
14305 (comment "Bob's sister"))
14308 Here's a user account that uses a different shell and a custom home
14309 directory (the default would be @file{"/home/bob"}):
14315 (comment "Alice's bro")
14316 (shell (file-append zsh "/bin/zsh"))
14317 (home-directory "/home/robert"))
14320 When booting or upon completion of @command{guix system reconfigure},
14321 the system ensures that only the user accounts and groups specified in
14322 the @code{operating-system} declaration exist, and with the specified
14323 properties. Thus, account or group creations or modifications made by
14324 directly invoking commands such as @command{useradd} are lost upon
14325 reconfiguration or reboot. This ensures that the system remains exactly
14328 @deftp {Data Type} user-account
14329 Objects of this type represent user accounts. The following members may
14334 The name of the user account.
14338 This is the name (a string) or identifier (a number) of the user group
14339 this account belongs to.
14341 @item @code{supplementary-groups} (default: @code{'()})
14342 Optionally, this can be defined as a list of group names that this
14343 account belongs to.
14345 @item @code{uid} (default: @code{#f})
14346 This is the user ID for this account (a number), or @code{#f}. In the
14347 latter case, a number is automatically chosen by the system when the
14348 account is created.
14350 @item @code{comment} (default: @code{""})
14351 A comment about the account, such as the account owner's full name.
14353 @item @code{home-directory}
14354 This is the name of the home directory for the account.
14356 @item @code{create-home-directory?} (default: @code{#t})
14357 Indicates whether the home directory of this account should be created
14358 if it does not exist yet.
14360 @item @code{shell} (default: Bash)
14361 This is a G-expression denoting the file name of a program to be used as
14362 the shell (@pxref{G-Expressions}). For example, you would refer to the
14363 Bash executable like this:
14366 (file-append bash "/bin/bash")
14370 ... and to the Zsh executable like that:
14373 (file-append zsh "/bin/zsh")
14376 @item @code{system?} (default: @code{#f})
14377 This Boolean value indicates whether the account is a ``system''
14378 account. System accounts are sometimes treated specially; for instance,
14379 graphical login managers do not list them.
14381 @anchor{user-account-password}
14382 @cindex password, for user accounts
14383 @item @code{password} (default: @code{#f})
14384 You would normally leave this field to @code{#f}, initialize user
14385 passwords as @code{root} with the @command{passwd} command, and then let
14386 users change it with @command{passwd}. Passwords set with
14387 @command{passwd} are of course preserved across reboot and
14390 If you @emph{do} want to set an initial password for an account, then
14391 this field must contain the encrypted password, as a string. You can use the
14392 @code{crypt} procedure for this purpose:
14399 ;; Specify a SHA-512-hashed initial password.
14400 (password (crypt "InitialPassword!" "$6$abc")))
14404 The hash of this initial password will be available in a file in
14405 @file{/gnu/store}, readable by all the users, so this method must be used with
14409 @xref{Passphrase Storage,,, libc, The GNU C Library Reference Manual}, for
14410 more information on password encryption, and @ref{Encryption,,, guile, GNU
14411 Guile Reference Manual}, for information on Guile's @code{crypt} procedure.
14417 User group declarations are even simpler:
14420 (user-group (name "students"))
14423 @deftp {Data Type} user-group
14424 This type is for, well, user groups. There are just a few fields:
14428 The name of the group.
14430 @item @code{id} (default: @code{#f})
14431 The group identifier (a number). If @code{#f}, a new number is
14432 automatically allocated when the group is created.
14434 @item @code{system?} (default: @code{#f})
14435 This Boolean value indicates whether the group is a ``system'' group.
14436 System groups have low numerical IDs.
14438 @item @code{password} (default: @code{#f})
14439 What, user groups can have a password? Well, apparently yes. Unless
14440 @code{#f}, this field specifies the password of the group.
14445 For convenience, a variable lists all the basic user groups one may
14448 @defvr {Scheme Variable} %base-groups
14449 This is the list of basic user groups that users and/or packages expect
14450 to be present on the system. This includes groups such as ``root'',
14451 ``wheel'', and ``users'', as well as groups used to control access to
14452 specific devices such as ``audio'', ``disk'', and ``cdrom''.
14455 @defvr {Scheme Variable} %base-user-accounts
14456 This is the list of basic system accounts that programs may expect to
14457 find on a GNU/Linux system, such as the ``nobody'' account.
14459 Note that the ``root'' account is not included here. It is a
14460 special-case and is automatically added whether or not it is specified.
14463 @node Keyboard Layout
14464 @section Keyboard Layout
14466 @cindex keyboard layout
14468 To specify what each key of your keyboard does, you need to tell the operating
14469 system what @dfn{keyboard layout} you want to use. The default, when nothing
14470 is specified, is the US English QWERTY layout for 105-key PC keyboards.
14471 However, German speakers will usually prefer the German QWERTZ layout, French
14472 speakers will want the AZERTY layout, and so on; hackers might prefer Dvorak
14473 or bépo, and they might even want to further customize the effect of some of
14474 the keys. This section explains how to get that done.
14476 @cindex keyboard layout, definition
14477 There are three components that will want to know about your keyboard layout:
14481 The @emph{bootloader} may want to know what keyboard layout you want to use
14482 (@pxref{Bootloader Configuration, @code{keyboard-layout}}). This is useful if
14483 you want, for instance, to make sure that you can type the passphrase of your
14484 encrypted root partition using the right layout.
14487 The @emph{operating system kernel}, Linux, will need that so that the console
14488 is properly configured (@pxref{operating-system Reference,
14489 @code{keyboard-layout}}).
14492 The @emph{graphical display server}, usually Xorg, also has its own idea of
14493 the keyboard layout (@pxref{X Window, @code{keyboard-layout}}).
14496 Guix allows you to configure all three separately but, fortunately, it allows
14497 you to share the same keyboard layout for all three components.
14499 @cindex XKB, keyboard layouts
14500 Keyboard layouts are represented by records created by the
14501 @code{keyboard-layout} procedure of @code{(gnu system keyboard)}. Following
14502 the X Keyboard extension (XKB), each layout has four attributes: a name (often
14503 a language code such as ``fi'' for Finnish or ``jp'' for Japanese), an
14504 optional variant name, an optional keyboard model name, and a possibly empty
14505 list of additional options. In most cases the layout name is all you care
14508 @deffn {Scheme Procedure} keyboard-layout @var{name} [@var{variant}] @
14509 [#:model] [#:options '()]
14510 Return a new keyboard layout with the given @var{name} and @var{variant}.
14512 @var{name} must be a string such as @code{"fr"}; @var{variant} must be a
14513 string such as @code{"bepo"} or @code{"nodeadkeys"}. See the
14514 @code{xkeyboard-config} package for valid options.
14517 Here are a few examples:
14520 ;; The German QWERTZ layout. Here we assume a standard
14521 ;; "pc105" keyboard model.
14522 (keyboard-layout "de")
14524 ;; The bépo variant of the French layout.
14525 (keyboard-layout "fr" "bepo")
14527 ;; The Catalan layout.
14528 (keyboard-layout "es" "cat")
14530 ;; Arabic layout with "Alt-Shift" to switch to US layout.
14531 (keyboard-layout "ar,us" #:options '("grp:alt_shift_toggle"))
14533 ;; The Latin American Spanish layout. In addition, the
14534 ;; "Caps Lock" key is used as an additional "Ctrl" key,
14535 ;; and the "Menu" key is used as a "Compose" key to enter
14536 ;; accented letters.
14537 (keyboard-layout "latam"
14538 #:options '("ctrl:nocaps" "compose:menu"))
14540 ;; The Russian layout for a ThinkPad keyboard.
14541 (keyboard-layout "ru" #:model "thinkpad")
14543 ;; The "US international" layout, which is the US layout plus
14544 ;; dead keys to enter accented characters. This is for an
14545 ;; Apple MacBook keyboard.
14546 (keyboard-layout "us" "intl" #:model "macbook78")
14549 See the @file{share/X11/xkb} directory of the @code{xkeyboard-config} package
14550 for a complete list of supported layouts, variants, and models.
14552 @cindex keyboard layout, configuration
14553 Let's say you want your system to use the Turkish keyboard layout throughout
14554 your system---bootloader, console, and Xorg. Here's what your system
14555 configuration would look like:
14557 @findex set-xorg-configuration
14559 ;; Using the Turkish layout for the bootloader, the console,
14564 (keyboard-layout (keyboard-layout "tr")) ;for the console
14565 (bootloader (bootloader-configuration
14566 (bootloader grub-efi-bootloader)
14567 (target "/boot/efi")
14568 (keyboard-layout keyboard-layout))) ;for GRUB
14569 (services (cons (set-xorg-configuration
14570 (xorg-configuration ;for Xorg
14571 (keyboard-layout keyboard-layout)))
14572 %desktop-services)))
14575 In the example above, for GRUB and for Xorg, we just refer to the
14576 @code{keyboard-layout} field defined above, but we could just as well refer to
14577 a different layout. The @code{set-xorg-configuration} procedure communicates
14578 the desired Xorg configuration to the graphical log-in manager, by default
14581 We've discussed how to specify the @emph{default} keyboard layout of your
14582 system when it starts, but you can also adjust it at run time:
14586 If you're using GNOME, its settings panel has a ``Region & Language'' entry
14587 where you can select one or more keyboard layouts.
14590 Under Xorg, the @command{setxkbmap} command (from the same-named package)
14591 allows you to change the current layout. For example, this is how you would
14592 change the layout to US Dvorak:
14595 setxkbmap us dvorak
14599 The @code{loadkeys} command changes the keyboard layout in effect in the Linux
14600 console. However, note that @code{loadkeys} does @emph{not} use the XKB
14601 keyboard layout categorization described above. The command below loads the
14602 French bépo layout:
14613 A @dfn{locale} defines cultural conventions for a particular language
14614 and region of the world (@pxref{Locales,,, libc, The GNU C Library
14615 Reference Manual}). Each locale has a name that typically has the form
14616 @code{@var{language}_@var{territory}.@var{codeset}}---e.g.,
14617 @code{fr_LU.utf8} designates the locale for the French language, with
14618 cultural conventions from Luxembourg, and using the UTF-8 encoding.
14620 @cindex locale definition
14621 Usually, you will want to specify the default locale for the machine
14622 using the @code{locale} field of the @code{operating-system} declaration
14623 (@pxref{operating-system Reference, @code{locale}}).
14625 The selected locale is automatically added to the @dfn{locale
14626 definitions} known to the system if needed, with its codeset inferred
14627 from its name---e.g., @code{bo_CN.utf8} will be assumed to use the
14628 @code{UTF-8} codeset. Additional locale definitions can be specified in
14629 the @code{locale-definitions} slot of @code{operating-system}---this is
14630 useful, for instance, if the codeset could not be inferred from the
14631 locale name. The default set of locale definitions includes some widely
14632 used locales, but not all the available locales, in order to save space.
14634 For instance, to add the North Frisian locale for Germany, the value of
14638 (cons (locale-definition
14639 (name "fy_DE.utf8") (source "fy_DE"))
14640 %default-locale-definitions)
14643 Likewise, to save space, one might want @code{locale-definitions} to
14644 list only the locales that are actually used, as in:
14647 (list (locale-definition
14648 (name "ja_JP.eucjp") (source "ja_JP")
14649 (charset "EUC-JP")))
14653 The compiled locale definitions are available at
14654 @file{/run/current-system/locale/X.Y}, where @code{X.Y} is the libc
14655 version, which is the default location where the GNU@tie{}libc provided
14656 by Guix looks for locale data. This can be overridden using the
14657 @env{LOCPATH} environment variable (@pxref{locales-and-locpath,
14658 @env{LOCPATH} and locale packages}).
14660 The @code{locale-definition} form is provided by the @code{(gnu system
14661 locale)} module. Details are given below.
14663 @deftp {Data Type} locale-definition
14664 This is the data type of a locale definition.
14669 The name of the locale. @xref{Locale Names,,, libc, The GNU C Library
14670 Reference Manual}, for more information on locale names.
14672 @item @code{source}
14673 The name of the source for that locale. This is typically the
14674 @code{@var{language}_@var{territory}} part of the locale name.
14676 @item @code{charset} (default: @code{"UTF-8"})
14677 The ``character set'' or ``code set'' for that locale,
14678 @uref{https://www.iana.org/assignments/character-sets, as defined by
14684 @defvr {Scheme Variable} %default-locale-definitions
14685 A list of commonly used UTF-8 locales, used as the default
14686 value of the @code{locale-definitions} field of @code{operating-system}
14689 @cindex locale name
14690 @cindex normalized codeset in locale names
14691 These locale definitions use the @dfn{normalized codeset} for the part
14692 that follows the dot in the name (@pxref{Using gettextized software,
14693 normalized codeset,, libc, The GNU C Library Reference Manual}). So for
14694 instance it has @code{uk_UA.utf8} but @emph{not}, say,
14695 @code{uk_UA.UTF-8}.
14698 @subsection Locale Data Compatibility Considerations
14700 @cindex incompatibility, of locale data
14701 @code{operating-system} declarations provide a @code{locale-libcs} field
14702 to specify the GNU@tie{}libc packages that are used to compile locale
14703 declarations (@pxref{operating-system Reference}). ``Why would I
14704 care?'', you may ask. Well, it turns out that the binary format of
14705 locale data is occasionally incompatible from one libc version to
14708 @c See <https://sourceware.org/ml/libc-alpha/2015-09/msg00575.html>
14709 @c and <https://lists.gnu.org/archive/html/guix-devel/2015-08/msg00737.html>.
14710 For instance, a program linked against libc version 2.21 is unable to
14711 read locale data produced with libc 2.22; worse, that program
14712 @emph{aborts} instead of simply ignoring the incompatible locale
14713 data@footnote{Versions 2.23 and later of GNU@tie{}libc will simply skip
14714 the incompatible locale data, which is already an improvement.}.
14715 Similarly, a program linked against libc 2.22 can read most, but not
14716 all, of the locale data from libc 2.21 (specifically, @env{LC_COLLATE}
14717 data is incompatible); thus calls to @code{setlocale} may fail, but
14718 programs will not abort.
14720 The ``problem'' with Guix is that users have a lot of freedom: They can
14721 choose whether and when to upgrade software in their profiles, and might
14722 be using a libc version different from the one the system administrator
14723 used to build the system-wide locale data.
14725 Fortunately, unprivileged users can also install their own locale data
14726 and define @env{GUIX_LOCPATH} accordingly (@pxref{locales-and-locpath,
14727 @env{GUIX_LOCPATH} and locale packages}).
14729 Still, it is best if the system-wide locale data at
14730 @file{/run/current-system/locale} is built for all the libc versions
14731 actually in use on the system, so that all the programs can access
14732 it---this is especially crucial on a multi-user system. To do that, the
14733 administrator can specify several libc packages in the
14734 @code{locale-libcs} field of @code{operating-system}:
14737 (use-package-modules base)
14741 (locale-libcs (list glibc-2.21 (canonical-package glibc))))
14744 This example would lead to a system containing locale definitions for
14745 both libc 2.21 and the current version of libc in
14746 @file{/run/current-system/locale}.
14752 @cindex system services
14753 An important part of preparing an @code{operating-system} declaration is
14754 listing @dfn{system services} and their configuration (@pxref{Using the
14755 Configuration System}). System services are typically daemons launched
14756 when the system boots, or other actions needed at that time---e.g.,
14757 configuring network access.
14759 Guix has a broad definition of ``service'' (@pxref{Service
14760 Composition}), but many services are managed by the GNU@tie{}Shepherd
14761 (@pxref{Shepherd Services}). On a running system, the @command{herd}
14762 command allows you to list the available services, show their status,
14763 start and stop them, or do other specific operations (@pxref{Jump
14764 Start,,, shepherd, The GNU Shepherd Manual}). For example:
14770 The above command, run as @code{root}, lists the currently defined
14771 services. The @command{herd doc} command shows a synopsis of the given
14772 service and its associated actions:
14776 Run libc's name service cache daemon (nscd).
14778 # herd doc nscd action invalidate
14779 invalidate: Invalidate the given cache--e.g., 'hosts' for host name lookups.
14782 The @command{start}, @command{stop}, and @command{restart} sub-commands
14783 have the effect you would expect. For instance, the commands below stop
14784 the nscd service and restart the Xorg display server:
14788 Service nscd has been stopped.
14789 # herd restart xorg-server
14790 Service xorg-server has been stopped.
14791 Service xorg-server has been started.
14794 The following sections document the available services, starting with
14795 the core services, that may be used in an @code{operating-system}
14799 * Base Services:: Essential system services.
14800 * Scheduled Job Execution:: The mcron service.
14801 * Log Rotation:: The rottlog service.
14802 * Networking Services:: Network setup, SSH daemon, etc.
14803 * Unattended Upgrades:: Automated system upgrades.
14804 * X Window:: Graphical display.
14805 * Printing Services:: Local and remote printer support.
14806 * Desktop Services:: D-Bus and desktop services.
14807 * Sound Services:: ALSA and Pulseaudio services.
14808 * Database Services:: SQL databases, key-value stores, etc.
14809 * Mail Services:: IMAP, POP3, SMTP, and all that.
14810 * Messaging Services:: Messaging services.
14811 * Telephony Services:: Telephony services.
14812 * File-Sharing Services:: File-sharing services.
14813 * Monitoring Services:: Monitoring services.
14814 * Kerberos Services:: Kerberos services.
14815 * LDAP Services:: LDAP services.
14816 * Web Services:: Web servers.
14817 * Certificate Services:: TLS certificates via Let's Encrypt.
14818 * DNS Services:: DNS daemons.
14819 * VPN Services:: VPN daemons.
14820 * Network File System:: NFS related services.
14821 * Continuous Integration:: The Cuirass service.
14822 * Power Management Services:: Extending battery life.
14823 * Audio Services:: The MPD.
14824 * Virtualization Services:: Virtualization services.
14825 * Version Control Services:: Providing remote access to Git repositories.
14826 * Game Services:: Game servers.
14827 * PAM Mount Service:: Service to mount volumes when logging in.
14828 * Guix Services:: Services relating specifically to Guix.
14829 * Linux Services:: Services tied to the Linux kernel.
14830 * Hurd Services:: Services specific for a Hurd System.
14831 * Miscellaneous Services:: Other services.
14834 @node Base Services
14835 @subsection Base Services
14837 The @code{(gnu services base)} module provides definitions for the basic
14838 services that one expects from the system. The services exported by
14839 this module are listed below.
14841 @defvr {Scheme Variable} %base-services
14842 This variable contains a list of basic services (@pxref{Service Types
14843 and Services}, for more information on service objects) one would
14844 expect from the system: a login service (mingetty) on each tty, syslogd,
14845 the libc name service cache daemon (nscd), the udev device manager, and
14848 This is the default value of the @code{services} field of
14849 @code{operating-system} declarations. Usually, when customizing a
14850 system, you will want to append services to @code{%base-services}, like
14854 (append (list (service avahi-service-type)
14855 (service openssh-service-type))
14860 @defvr {Scheme Variable} special-files-service-type
14861 This is the service that sets up ``special files'' such as
14862 @file{/bin/sh}; an instance of it is part of @code{%base-services}.
14864 The value associated with @code{special-files-service-type} services
14865 must be a list of tuples where the first element is the ``special file''
14866 and the second element is its target. By default it is:
14868 @cindex @file{/bin/sh}
14869 @cindex @file{sh}, in @file{/bin}
14871 `(("/bin/sh" ,(file-append bash "/bin/sh")))
14874 @cindex @file{/usr/bin/env}
14875 @cindex @file{env}, in @file{/usr/bin}
14876 If you want to add, say, @code{/usr/bin/env} to your system, you can
14880 `(("/bin/sh" ,(file-append bash "/bin/sh"))
14881 ("/usr/bin/env" ,(file-append coreutils "/bin/env")))
14884 Since this is part of @code{%base-services}, you can use
14885 @code{modify-services} to customize the set of special files
14886 (@pxref{Service Reference, @code{modify-services}}). But the simple way
14887 to add a special file is @i{via} the @code{extra-special-file} procedure
14891 @deffn {Scheme Procedure} extra-special-file @var{file} @var{target}
14892 Use @var{target} as the ``special file'' @var{file}.
14894 For example, adding the following lines to the @code{services} field of
14895 your operating system declaration leads to a @file{/usr/bin/env}
14899 (extra-special-file "/usr/bin/env"
14900 (file-append coreutils "/bin/env"))
14904 @deffn {Scheme Procedure} host-name-service @var{name}
14905 Return a service that sets the host name to @var{name}.
14908 @defvr {Scheme Variable} console-font-service-type
14909 Install the given fonts on the specified ttys (fonts are per
14910 virtual console on the kernel Linux). The value of this service is a list of
14911 tty/font pairs. The font can be the name of a font provided by the @code{kbd}
14912 package or any valid argument to @command{setfont}, as in this example:
14915 `(("tty1" . "LatGrkCyr-8x16")
14916 ("tty2" . ,(file-append
14918 "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
14919 ("tty3" . ,(file-append
14921 "/share/consolefonts/ter-132n"))) ; for HDPI
14925 @deffn {Scheme Procedure} login-service @var{config}
14926 Return a service to run login according to @var{config}, a
14927 @code{<login-configuration>} object, which specifies the message of the day,
14928 among other things.
14931 @deftp {Data Type} login-configuration
14932 This is the data type representing the configuration of login.
14937 @cindex message of the day
14938 A file-like object containing the ``message of the day''.
14940 @item @code{allow-empty-passwords?} (default: @code{#t})
14941 Allow empty passwords by default so that first-time users can log in when
14942 the 'root' account has just been created.
14947 @deffn {Scheme Procedure} mingetty-service @var{config}
14948 Return a service to run mingetty according to @var{config}, a
14949 @code{<mingetty-configuration>} object, which specifies the tty to run, among
14953 @deftp {Data Type} mingetty-configuration
14954 This is the data type representing the configuration of Mingetty, which
14955 provides the default implementation of virtual console log-in.
14960 The name of the console this Mingetty runs on---e.g., @code{"tty1"}.
14962 @item @code{auto-login} (default: @code{#f})
14963 When true, this field must be a string denoting the user name under
14964 which the system automatically logs in. When it is @code{#f}, a
14965 user name and password must be entered to log in.
14967 @item @code{login-program} (default: @code{#f})
14968 This must be either @code{#f}, in which case the default log-in program
14969 is used (@command{login} from the Shadow tool suite), or a gexp denoting
14970 the name of the log-in program.
14972 @item @code{login-pause?} (default: @code{#f})
14973 When set to @code{#t} in conjunction with @var{auto-login}, the user
14974 will have to press a key before the log-in shell is launched.
14976 @item @code{clear-on-logout?} (default: @code{#t})
14977 When set to @code{#t}, the screen will be cleared after logout.
14979 @item @code{mingetty} (default: @var{mingetty})
14980 The Mingetty package to use.
14985 @deffn {Scheme Procedure} agetty-service @var{config}
14986 Return a service to run agetty according to @var{config}, an
14987 @code{<agetty-configuration>} object, which specifies the tty to run,
14988 among other things.
14991 @deftp {Data Type} agetty-configuration
14992 This is the data type representing the configuration of agetty, which
14993 implements virtual and serial console log-in. See the @code{agetty(8)}
14994 man page for more information.
14999 The name of the console this agetty runs on, as a string---e.g.,
15000 @code{"ttyS0"}. This argument is optional, it will default to
15001 a reasonable default serial port used by the kernel Linux.
15003 For this, if there is a value for an option @code{agetty.tty} in the kernel
15004 command line, agetty will extract the device name of the serial port
15005 from it and use that.
15007 If not and if there is a value for an option @code{console} with a tty in
15008 the Linux command line, agetty will extract the device name of the
15009 serial port from it and use that.
15011 In both cases, agetty will leave the other serial device settings
15012 (baud rate etc.)@: alone---in the hope that Linux pinned them to the
15015 @item @code{baud-rate} (default: @code{#f})
15016 A string containing a comma-separated list of one or more baud rates, in
15019 @item @code{term} (default: @code{#f})
15020 A string containing the value used for the @env{TERM} environment
15023 @item @code{eight-bits?} (default: @code{#f})
15024 When @code{#t}, the tty is assumed to be 8-bit clean, and parity detection is
15027 @item @code{auto-login} (default: @code{#f})
15028 When passed a login name, as a string, the specified user will be logged
15029 in automatically without prompting for their login name or password.
15031 @item @code{no-reset?} (default: @code{#f})
15032 When @code{#t}, don't reset terminal cflags (control modes).
15034 @item @code{host} (default: @code{#f})
15035 This accepts a string containing the ``login_host'', which will be written
15036 into the @file{/var/run/utmpx} file.
15038 @item @code{remote?} (default: @code{#f})
15039 When set to @code{#t} in conjunction with @var{host}, this will add an
15040 @code{-r} fakehost option to the command line of the login program
15041 specified in @var{login-program}.
15043 @item @code{flow-control?} (default: @code{#f})
15044 When set to @code{#t}, enable hardware (RTS/CTS) flow control.
15046 @item @code{no-issue?} (default: @code{#f})
15047 When set to @code{#t}, the contents of the @file{/etc/issue} file will
15048 not be displayed before presenting the login prompt.
15050 @item @code{init-string} (default: @code{#f})
15051 This accepts a string that will be sent to the tty or modem before
15052 sending anything else. It can be used to initialize a modem.
15054 @item @code{no-clear?} (default: @code{#f})
15055 When set to @code{#t}, agetty will not clear the screen before showing
15058 @item @code{login-program} (default: (file-append shadow "/bin/login"))
15059 This must be either a gexp denoting the name of a log-in program, or
15060 unset, in which case the default value is the @command{login} from the
15063 @item @code{local-line} (default: @code{#f})
15064 Control the CLOCAL line flag. This accepts one of three symbols as
15065 arguments, @code{'auto}, @code{'always}, or @code{'never}. If @code{#f},
15066 the default value chosen by agetty is @code{'auto}.
15068 @item @code{extract-baud?} (default: @code{#f})
15069 When set to @code{#t}, instruct agetty to try to extract the baud rate
15070 from the status messages produced by certain types of modems.
15072 @item @code{skip-login?} (default: @code{#f})
15073 When set to @code{#t}, do not prompt the user for a login name. This
15074 can be used with @var{login-program} field to use non-standard login
15077 @item @code{no-newline?} (default: @code{#f})
15078 When set to @code{#t}, do not print a newline before printing the
15079 @file{/etc/issue} file.
15081 @c Is this dangerous only when used with login-program, or always?
15082 @item @code{login-options} (default: @code{#f})
15083 This option accepts a string containing options that are passed to the
15084 login program. When used with the @var{login-program}, be aware that a
15085 malicious user could try to enter a login name containing embedded
15086 options that could be parsed by the login program.
15088 @item @code{login-pause} (default: @code{#f})
15089 When set to @code{#t}, wait for any key before showing the login prompt.
15090 This can be used in conjunction with @var{auto-login} to save memory by
15091 lazily spawning shells.
15093 @item @code{chroot} (default: @code{#f})
15094 Change root to the specified directory. This option accepts a directory
15097 @item @code{hangup?} (default: @code{#f})
15098 Use the Linux system call @code{vhangup} to do a virtual hangup of the
15099 specified terminal.
15101 @item @code{keep-baud?} (default: @code{#f})
15102 When set to @code{#t}, try to keep the existing baud rate. The baud
15103 rates from @var{baud-rate} are used when agetty receives a @key{BREAK}
15106 @item @code{timeout} (default: @code{#f})
15107 When set to an integer value, terminate if no user name could be read
15108 within @var{timeout} seconds.
15110 @item @code{detect-case?} (default: @code{#f})
15111 When set to @code{#t}, turn on support for detecting an uppercase-only
15112 terminal. This setting will detect a login name containing only
15113 uppercase letters as indicating an uppercase-only terminal and turn on
15114 some upper-to-lower case conversions. Note that this will not support
15115 Unicode characters.
15117 @item @code{wait-cr?} (default: @code{#f})
15118 When set to @code{#t}, wait for the user or modem to send a
15119 carriage-return or linefeed character before displaying
15120 @file{/etc/issue} or login prompt. This is typically used with the
15121 @var{init-string} option.
15123 @item @code{no-hints?} (default: @code{#f})
15124 When set to @code{#t}, do not print hints about Num, Caps, and Scroll
15127 @item @code{no-hostname?} (default: @code{#f})
15128 By default, the hostname is printed. When this option is set to
15129 @code{#t}, no hostname will be shown at all.
15131 @item @code{long-hostname?} (default: @code{#f})
15132 By default, the hostname is only printed until the first dot. When this
15133 option is set to @code{#t}, the fully qualified hostname by
15134 @code{gethostname} or @code{getaddrinfo} is shown.
15136 @item @code{erase-characters} (default: @code{#f})
15137 This option accepts a string of additional characters that should be
15138 interpreted as backspace when the user types their login name.
15140 @item @code{kill-characters} (default: @code{#f})
15141 This option accepts a string that should be interpreted to mean ``ignore
15142 all previous characters'' (also called a ``kill'' character) when the user
15143 types their login name.
15145 @item @code{chdir} (default: @code{#f})
15146 This option accepts, as a string, a directory path that will be changed
15149 @item @code{delay} (default: @code{#f})
15150 This options accepts, as an integer, the number of seconds to sleep
15151 before opening the tty and displaying the login prompt.
15153 @item @code{nice} (default: @code{#f})
15154 This option accepts, as an integer, the nice value with which to run the
15155 @command{login} program.
15157 @item @code{extra-options} (default: @code{'()})
15158 This option provides an ``escape hatch'' for the user to provide arbitrary
15159 command-line arguments to @command{agetty} as a list of strings.
15164 @deffn {Scheme Procedure} kmscon-service-type @var{config}
15165 Return a service to run @uref{https://www.freedesktop.org/wiki/Software/kmscon,kmscon}
15166 according to @var{config}, a @code{<kmscon-configuration>} object, which
15167 specifies the tty to run, among other things.
15170 @deftp {Data Type} kmscon-configuration
15171 This is the data type representing the configuration of Kmscon, which
15172 implements virtual console log-in.
15176 @item @code{virtual-terminal}
15177 The name of the console this Kmscon runs on---e.g., @code{"tty1"}.
15179 @item @code{login-program} (default: @code{#~(string-append #$shadow "/bin/login")})
15180 A gexp denoting the name of the log-in program. The default log-in program is
15181 @command{login} from the Shadow tool suite.
15183 @item @code{login-arguments} (default: @code{'("-p")})
15184 A list of arguments to pass to @command{login}.
15186 @item @code{auto-login} (default: @code{#f})
15187 When passed a login name, as a string, the specified user will be logged
15188 in automatically without prompting for their login name or password.
15190 @item @code{hardware-acceleration?} (default: #f)
15191 Whether to use hardware acceleration.
15193 @item @code{font-engine} (default: @code{"pango"})
15194 Font engine used in Kmscon.
15196 @item @code{font-size} (default: @code{12})
15197 Font size used in Kmscon.
15199 @item @code{kmscon} (default: @var{kmscon})
15200 The Kmscon package to use.
15205 @cindex name service cache daemon
15207 @deffn {Scheme Procedure} nscd-service [@var{config}] [#:glibc glibc] @
15208 [#:name-services '()]
15209 Return a service that runs the libc name service cache daemon (nscd) with the
15210 given @var{config}---an @code{<nscd-configuration>} object. @xref{Name
15211 Service Switch}, for an example.
15213 For convenience, the Shepherd service for nscd provides the following actions:
15217 @cindex cache invalidation, nscd
15218 @cindex nscd, cache invalidation
15219 This invalidate the given cache. For instance, running:
15222 herd invalidate nscd hosts
15226 invalidates the host name lookup cache of nscd.
15229 Running @command{herd statistics nscd} displays information about nscd usage
15235 @defvr {Scheme Variable} %nscd-default-configuration
15236 This is the default @code{<nscd-configuration>} value (see below) used
15237 by @code{nscd-service}. It uses the caches defined by
15238 @code{%nscd-default-caches}; see below.
15241 @deftp {Data Type} nscd-configuration
15242 This is the data type representing the name service cache daemon (nscd)
15247 @item @code{name-services} (default: @code{'()})
15248 List of packages denoting @dfn{name services} that must be visible to
15249 the nscd---e.g., @code{(list @var{nss-mdns})}.
15251 @item @code{glibc} (default: @var{glibc})
15252 Package object denoting the GNU C Library providing the @command{nscd}
15255 @item @code{log-file} (default: @code{"/var/log/nscd.log"})
15256 Name of the nscd log file. This is where debugging output goes when
15257 @code{debug-level} is strictly positive.
15259 @item @code{debug-level} (default: @code{0})
15260 Integer denoting the debugging levels. Higher numbers mean that more
15261 debugging output is logged.
15263 @item @code{caches} (default: @code{%nscd-default-caches})
15264 List of @code{<nscd-cache>} objects denoting things to be cached; see
15270 @deftp {Data Type} nscd-cache
15271 Data type representing a cache database of nscd and its parameters.
15275 @item @code{database}
15276 This is a symbol representing the name of the database to be cached.
15277 Valid values are @code{passwd}, @code{group}, @code{hosts}, and
15278 @code{services}, which designate the corresponding NSS database
15279 (@pxref{NSS Basics,,, libc, The GNU C Library Reference Manual}).
15281 @item @code{positive-time-to-live}
15282 @itemx @code{negative-time-to-live} (default: @code{20})
15283 A number representing the number of seconds during which a positive or
15284 negative lookup result remains in cache.
15286 @item @code{check-files?} (default: @code{#t})
15287 Whether to check for updates of the files corresponding to
15290 For instance, when @var{database} is @code{hosts}, setting this flag
15291 instructs nscd to check for updates in @file{/etc/hosts} and to take
15294 @item @code{persistent?} (default: @code{#t})
15295 Whether the cache should be stored persistently on disk.
15297 @item @code{shared?} (default: @code{#t})
15298 Whether the cache should be shared among users.
15300 @item @code{max-database-size} (default: 32@tie{}MiB)
15301 Maximum size in bytes of the database cache.
15303 @c XXX: 'suggested-size' and 'auto-propagate?' seem to be expert
15304 @c settings, so leave them out.
15309 @defvr {Scheme Variable} %nscd-default-caches
15310 List of @code{<nscd-cache>} objects used by default by
15311 @code{nscd-configuration} (see above).
15313 It enables persistent and aggressive caching of service and host name
15314 lookups. The latter provides better host name lookup performance,
15315 resilience in the face of unreliable name servers, and also better
15316 privacy---often the result of host name lookups is in local cache, so
15317 external name servers do not even need to be queried.
15320 @anchor{syslog-configuration-type}
15323 @deftp {Data Type} syslog-configuration
15324 This data type represents the configuration of the syslog daemon.
15327 @item @code{syslogd} (default: @code{#~(string-append #$inetutils "/libexec/syslogd")})
15328 The syslog daemon to use.
15330 @item @code{config-file} (default: @code{%default-syslog.conf})
15331 The syslog configuration file to use.
15336 @anchor{syslog-service}
15338 @deffn {Scheme Procedure} syslog-service @var{config}
15339 Return a service that runs a syslog daemon according to @var{config}.
15341 @xref{syslogd invocation,,, inetutils, GNU Inetutils}, for more
15342 information on the configuration file syntax.
15345 @defvr {Scheme Variable} guix-service-type
15346 This is the type of the service that runs the build daemon,
15347 @command{guix-daemon} (@pxref{Invoking guix-daemon}). Its value must be a
15348 @code{guix-configuration} record as described below.
15351 @anchor{guix-configuration-type}
15352 @deftp {Data Type} guix-configuration
15353 This data type represents the configuration of the Guix build daemon.
15354 @xref{Invoking guix-daemon}, for more information.
15357 @item @code{guix} (default: @var{guix})
15358 The Guix package to use.
15360 @item @code{build-group} (default: @code{"guixbuild"})
15361 Name of the group for build user accounts.
15363 @item @code{build-accounts} (default: @code{10})
15364 Number of build user accounts to create.
15366 @item @code{authorize-key?} (default: @code{#t})
15367 @cindex substitutes, authorization thereof
15368 Whether to authorize the substitute keys listed in
15369 @code{authorized-keys}---by default that of @code{@value{SUBSTITUTE-SERVER}}
15370 (@pxref{Substitutes}).
15372 When @code{authorize-key?} is true, @file{/etc/guix/acl} cannot be
15373 changed by invoking @command{guix archive --authorize}. You must
15374 instead adjust @code{guix-configuration} as you wish and reconfigure the
15375 system. This ensures that your operating system configuration file is
15379 When booting or reconfiguring to a system where @code{authorize-key?}
15380 is true, the existing @file{/etc/guix/acl} file is backed up as
15381 @file{/etc/guix/acl.bak} if it was determined to be a manually modified
15382 file. This is to facilitate migration from earlier versions, which
15383 allowed for in-place modifications to @file{/etc/guix/acl}.
15386 @vindex %default-authorized-guix-keys
15387 @item @code{authorized-keys} (default: @code{%default-authorized-guix-keys})
15388 The list of authorized key files for archive imports, as a list of
15389 string-valued gexps (@pxref{Invoking guix archive}). By default, it
15390 contains that of @code{@value{SUBSTITUTE-SERVER}} (@pxref{Substitutes}).
15391 See @code{substitute-urls} below for an example on how to change it.
15393 @item @code{use-substitutes?} (default: @code{#t})
15394 Whether to use substitutes.
15396 @item @code{substitute-urls} (default: @code{%default-substitute-urls})
15397 The list of URLs where to look for substitutes by default.
15399 Suppose you would like to fetch substitutes from @code{guix.example.org}
15400 in addition to @code{@value{SUBSTITUTE-SERVER}}. You will need to do
15401 two things: (1) add @code{guix.example.org} to @code{substitute-urls},
15402 and (2) authorize its signing key, having done appropriate checks
15403 (@pxref{Substitute Server Authorization}). The configuration below does
15407 (guix-configuration
15409 (append (list "https://guix.example.org")
15410 %default-substitute-urls))
15412 (append (list (local-file "./guix.example.org-key.pub"))
15413 %default-authorized-guix-keys)))
15416 This example assumes that the file @file{./guix.example.org-key.pub}
15417 contains the public key that @code{guix.example.org} uses to sign
15420 @item @code{max-silent-time} (default: @code{0})
15421 @itemx @code{timeout} (default: @code{0})
15422 The number of seconds of silence and the number of seconds of activity,
15423 respectively, after which a build process times out. A value of zero
15424 disables the timeout.
15426 @item @code{log-compression} (default: @code{'bzip2})
15427 The type of compression used for build logs---one of @code{gzip},
15428 @code{bzip2}, or @code{none}.
15430 @item @code{discover?} (default: @code{#f})
15431 Whether to discover substitute servers on the local network using mDNS
15434 @item @code{extra-options} (default: @code{'()})
15435 List of extra command-line options for @command{guix-daemon}.
15437 @item @code{log-file} (default: @code{"/var/log/guix-daemon.log"})
15438 File where @command{guix-daemon}'s standard output and standard error
15441 @cindex HTTP proxy, for @code{guix-daemon}
15442 @cindex proxy, for @code{guix-daemon} HTTP access
15443 @item @code{http-proxy} (default: @code{#f})
15444 The URL of the HTTP and HTTPS proxy used for downloading fixed-output
15445 derivations and substitutes.
15447 It is also possible to change the daemon's proxy at run time through the
15448 @code{set-http-proxy} action, which restarts it:
15451 herd set-http-proxy guix-daemon http://localhost:8118
15454 To clear the proxy settings, run:
15457 herd set-http-proxy guix-daemon
15460 @item @code{tmpdir} (default: @code{#f})
15461 A directory path where the @command{guix-daemon} will perform builds.
15466 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
15467 Run @var{udev}, which populates the @file{/dev} directory dynamically.
15468 udev rules can be provided as a list of files through the @var{rules}
15469 variable. The procedures @code{udev-rule}, @code{udev-rules-service}
15470 and @code{file->udev-rule} from @code{(gnu services base)} simplify the
15471 creation of such rule files.
15473 The @command{herd rules udev} command, as root, returns the name of the
15474 directory containing all the active udev rules.
15477 @deffn {Scheme Procedure} udev-rule [@var{file-name} @var{contents}]
15478 Return a udev-rule file named @var{file-name} containing the rules
15479 defined by the @var{contents} literal.
15481 In the following example, a rule for a USB device is defined to be
15482 stored in the file @file{90-usb-thing.rules}. The rule runs a script
15483 upon detecting a USB device with a given product identifier.
15486 (define %example-udev-rule
15488 "90-usb-thing.rules"
15489 (string-append "ACTION==\"add\", SUBSYSTEM==\"usb\", "
15490 "ATTR@{product@}==\"Example\", "
15491 "RUN+=\"/path/to/script\"")))
15495 @deffn {Scheme Procedure} udev-rules-service [@var{name} @var{rules}] @
15496 [#:groups @var{groups}]
15497 Return a service that extends @code{udev-service-type } with @var{rules}
15498 and @code{account-service-type} with @var{groups} as system groups.
15499 This works by creating a singleton service type
15500 @code{@var{name}-udev-rules}, of which the returned service is an
15503 Here we show how it can be used to extend @code{udev-service-type} with the
15504 previously defined rule @code{%example-udev-rule}.
15510 (cons (udev-rules-service 'usb-thing %example-udev-rule)
15511 %desktop-services)))
15515 @deffn {Scheme Procedure} file->udev-rule [@var{file-name} @var{file}]
15516 Return a udev file named @var{file-name} containing the rules defined
15517 within @var{file}, a file-like object.
15519 The following example showcases how we can use an existing rule file.
15522 (use-modules (guix download) ;for url-fetch
15523 (guix packages) ;for origin
15526 (define %android-udev-rules
15528 "51-android-udev.rules"
15529 (let ((version "20170910"))
15532 (uri (string-append "https://raw.githubusercontent.com/M0Rf30/"
15533 "android-udev-rules/" version "/51-android.rules"))
15535 (base32 "0lmmagpyb6xsq6zcr2w1cyx9qmjqmajkvrdbhjx32gqf1d9is003"))))))
15539 Additionally, Guix package definitions can be included in @var{rules} in
15540 order to extend the udev rules with the definitions found under their
15541 @file{lib/udev/rules.d} sub-directory. In lieu of the previous
15542 @var{file->udev-rule} example, we could have used the
15543 @var{android-udev-rules} package which exists in Guix in the @code{(gnu
15544 packages android)} module.
15546 The following example shows how to use the @var{android-udev-rules}
15547 package so that the Android tool @command{adb} can detect devices
15548 without root privileges. It also details how to create the
15549 @code{adbusers} group, which is required for the proper functioning of
15550 the rules defined within the @code{android-udev-rules} package. To
15551 create such a group, we must define it both as part of the
15552 @code{supplementary-groups} of our @code{user-account} declaration, as
15553 well as in the @var{groups} of the @code{udev-rules-service} procedure.
15556 (use-modules (gnu packages android) ;for android-udev-rules
15557 (gnu system shadow) ;for user-group
15562 (users (cons (user-account
15564 (supplementary-groups
15565 '("adbusers" ;for adb
15566 "wheel" "netdev" "audio" "video")))))
15569 (cons (udev-rules-service 'android android-udev-rules
15570 #:groups '("adbusers"))
15571 %desktop-services)))
15574 @defvr {Scheme Variable} urandom-seed-service-type
15575 Save some entropy in @code{%random-seed-file} to seed @file{/dev/urandom}
15576 when rebooting. It also tries to seed @file{/dev/urandom} from
15577 @file{/dev/hwrng} while booting, if @file{/dev/hwrng} exists and is
15581 @defvr {Scheme Variable} %random-seed-file
15582 This is the name of the file where some random bytes are saved by
15583 @var{urandom-seed-service} to seed @file{/dev/urandom} when rebooting.
15584 It defaults to @file{/var/lib/random-seed}.
15589 @defvr {Scheme Variable} gpm-service-type
15590 This is the type of the service that runs GPM, the @dfn{general-purpose
15591 mouse daemon}, which provides mouse support to the Linux console. GPM
15592 allows users to use the mouse in the console, notably to select, copy,
15595 The value for services of this type must be a @code{gpm-configuration}
15596 (see below). This service is not part of @code{%base-services}.
15599 @deftp {Data Type} gpm-configuration
15600 Data type representing the configuration of GPM.
15603 @item @code{options} (default: @code{%default-gpm-options})
15604 Command-line options passed to @command{gpm}. The default set of
15605 options instruct @command{gpm} to listen to mouse events on
15606 @file{/dev/input/mice}. @xref{Command Line,,, gpm, gpm manual}, for
15609 @item @code{gpm} (default: @code{gpm})
15610 The GPM package to use.
15615 @anchor{guix-publish-service-type}
15616 @deffn {Scheme Variable} guix-publish-service-type
15617 This is the service type for @command{guix publish} (@pxref{Invoking
15618 guix publish}). Its value must be a @code{guix-publish-configuration}
15619 object, as described below.
15621 This assumes that @file{/etc/guix} already contains a signing key pair as
15622 created by @command{guix archive --generate-key} (@pxref{Invoking guix
15623 archive}). If that is not the case, the service will fail to start.
15626 @deftp {Data Type} guix-publish-configuration
15627 Data type representing the configuration of the @code{guix publish}
15631 @item @code{guix} (default: @code{guix})
15632 The Guix package to use.
15634 @item @code{port} (default: @code{80})
15635 The TCP port to listen for connections.
15637 @item @code{host} (default: @code{"localhost"})
15638 The host (and thus, network interface) to listen to. Use
15639 @code{"0.0.0.0"} to listen on all the network interfaces.
15641 @item @code{advertise?} (default: @code{#f})
15642 When true, advertise the service on the local network @i{via} the DNS-SD
15643 protocol, using Avahi.
15645 This allows neighboring Guix devices with discovery on (see
15646 @code{guix-configuration} above) to discover this @command{guix publish}
15647 instance and to automatically download substitutes from it.
15649 @item @code{compression} (default: @code{'(("gzip" 3) ("zstd" 3))})
15650 This is a list of compression method/level tuple used when compressing
15651 substitutes. For example, to compress all substitutes with @emph{both} lzip
15652 at level 7 and gzip at level 9, write:
15655 '(("lzip" 7) ("gzip" 9))
15658 Level 9 achieves the best compression ratio at the expense of increased CPU
15659 usage, whereas level 1 achieves fast compression. @xref{Invoking guix
15660 publish}, for more information on the available compression methods and
15661 the tradeoffs involved.
15663 An empty list disables compression altogether.
15665 @item @code{nar-path} (default: @code{"nar"})
15666 The URL path at which ``nars'' can be fetched. @xref{Invoking guix
15667 publish, @option{--nar-path}}, for details.
15669 @item @code{cache} (default: @code{#f})
15670 When it is @code{#f}, disable caching and instead generate archives on
15671 demand. Otherwise, this should be the name of a directory---e.g.,
15672 @code{"/var/cache/guix/publish"}---where @command{guix publish} caches
15673 archives and meta-data ready to be sent. @xref{Invoking guix publish,
15674 @option{--cache}}, for more information on the tradeoffs involved.
15676 @item @code{workers} (default: @code{#f})
15677 When it is an integer, this is the number of worker threads used for
15678 caching; when @code{#f}, the number of processors is used.
15679 @xref{Invoking guix publish, @option{--workers}}, for more information.
15681 @item @code{cache-bypass-threshold} (default: 10 MiB)
15682 When @code{cache} is true, this is the maximum size in bytes of a store
15683 item for which @command{guix publish} may bypass its cache in case of a
15684 cache miss. @xref{Invoking guix publish,
15685 @option{--cache-bypass-threshold}}, for more information.
15687 @item @code{ttl} (default: @code{#f})
15688 When it is an integer, this denotes the @dfn{time-to-live} in seconds
15689 of the published archives. @xref{Invoking guix publish, @option{--ttl}},
15690 for more information.
15694 @anchor{rngd-service}
15695 @deffn {Scheme Procedure} rngd-service [#:rng-tools @var{rng-tools}] @
15696 [#:device "/dev/hwrng"]
15697 Return a service that runs the @command{rngd} program from @var{rng-tools}
15698 to add @var{device} to the kernel's entropy pool. The service will fail if
15699 @var{device} does not exist.
15702 @anchor{pam-limits-service}
15703 @cindex session limits
15709 @cindex open file descriptors
15710 @deffn {Scheme Procedure} pam-limits-service [#:limits @code{'()}]
15712 Return a service that installs a configuration file for the
15713 @uref{http://linux-pam.org/Linux-PAM-html/sag-pam_limits.html,
15714 @code{pam_limits} module}. The procedure optionally takes a list of
15715 @code{pam-limits-entry} values, which can be used to specify
15716 @code{ulimit} limits and @code{nice} priority limits to user sessions.
15718 The following limits definition sets two hard and soft limits for all
15719 login sessions of users in the @code{realtime} group:
15722 (pam-limits-service
15724 (pam-limits-entry "@@realtime" 'both 'rtprio 99)
15725 (pam-limits-entry "@@realtime" 'both 'memlock 'unlimited)))
15728 The first entry increases the maximum realtime priority for
15729 non-privileged processes; the second entry lifts any restriction of the
15730 maximum address space that can be locked in memory. These settings are
15731 commonly used for real-time audio systems.
15733 Another useful example is raising the maximum number of open file
15734 descriptors that can be used:
15737 (pam-limits-service
15739 (pam-limits-entry "*" 'both 'nofile 100000)))
15742 In the above example, the asterisk means the limit should apply to any
15743 user. It is important to ensure the chosen value doesn't exceed the
15744 maximum system value visible in the @file{/proc/sys/fs/file-max} file,
15745 else the users would be prevented from login in. For more information
15746 about the Pluggable Authentication Module (PAM) limits, refer to the
15747 @samp{pam_limits} man page from the @code{linux-pam} package.
15750 @node Scheduled Job Execution
15751 @subsection Scheduled Job Execution
15755 @cindex scheduling jobs
15756 The @code{(gnu services mcron)} module provides an interface to
15757 GNU@tie{}mcron, a daemon to run jobs at scheduled times (@pxref{Top,,,
15758 mcron, GNU@tie{}mcron}). GNU@tie{}mcron is similar to the traditional
15759 Unix @command{cron} daemon; the main difference is that it is
15760 implemented in Guile Scheme, which provides a lot of flexibility when
15761 specifying the scheduling of jobs and their actions.
15763 The example below defines an operating system that runs the
15764 @command{updatedb} (@pxref{Invoking updatedb,,, find, Finding Files})
15765 and the @command{guix gc} commands (@pxref{Invoking guix gc}) daily, as
15766 well as the @command{mkid} command on behalf of an unprivileged user
15767 (@pxref{mkid invocation,,, idutils, ID Database Utilities}). It uses
15768 gexps to introduce job definitions that are passed to mcron
15769 (@pxref{G-Expressions}).
15772 (use-modules (guix) (gnu) (gnu services mcron))
15773 (use-package-modules base idutils)
15775 (define updatedb-job
15776 ;; Run 'updatedb' at 3AM every day. Here we write the
15777 ;; job's action as a Scheme procedure.
15778 #~(job '(next-hour '(3))
15780 (execl (string-append #$findutils "/bin/updatedb")
15782 "--prunepaths=/tmp /var/tmp /gnu/store"))))
15784 (define garbage-collector-job
15785 ;; Collect garbage 5 minutes after midnight every day.
15786 ;; The job's action is a shell command.
15787 #~(job "5 0 * * *" ;Vixie cron syntax
15790 (define idutils-job
15791 ;; Update the index database as user "charlie" at 12:15PM
15792 ;; and 19:15PM. This runs from the user's home directory.
15793 #~(job '(next-minute-from (next-hour '(12 19)) '(15))
15794 (string-append #$idutils "/bin/mkid src")
15800 ;; %BASE-SERVICES already includes an instance of
15801 ;; 'mcron-service-type', which we extend with additional
15802 ;; jobs using 'simple-service'.
15803 (services (cons (simple-service 'my-cron-jobs
15805 (list garbage-collector-job
15811 For more complex jobs defined in Scheme where you need control over the top
15812 level, for instance to introduce a @code{use-modules} form, you can move your
15813 code to a separate program using the @code{program-file} procedure of the
15814 @code{(guix gexp)} module (@pxref{G-Expressions}). The example below
15818 (define %battery-alert-job
15819 ;; Beep when the battery percentage falls below %MIN-LEVEL.
15821 '(next-minute (range 0 60 1))
15823 "battery-alert.scm"
15824 (with-imported-modules (source-module-closure
15825 '((guix build utils)))
15827 (use-modules (guix build utils)
15830 (ice-9 textual-ports)
15833 (define %min-level 20)
15835 (setenv "LC_ALL" "C") ;ensure English output
15836 (and-let* ((input-pipe (open-pipe*
15838 #$(file-append acpi "/bin/acpi")))
15839 (output (get-string-all input-pipe))
15840 (m (string-match "Discharging, ([0-9]+)%" output))
15841 (level (string->number (match:substring m 1)))
15842 ((< level %min-level)))
15843 (format #t "warning: Battery level is low (~a%)~%" level)
15844 (invoke #$(file-append beep "/bin/beep") "-r5")))))))
15847 @xref{Guile Syntax, mcron job specifications,, mcron, GNU@tie{}mcron},
15848 for more information on mcron job specifications. Below is the
15849 reference of the mcron service.
15851 On a running system, you can use the @code{schedule} action of the service to
15852 visualize the mcron jobs that will be executed next:
15855 # herd schedule mcron
15859 The example above lists the next five tasks that will be executed, but you can
15860 also specify the number of tasks to display:
15863 # herd schedule mcron 10
15866 @defvr {Scheme Variable} mcron-service-type
15867 This is the type of the @code{mcron} service, whose value is an
15868 @code{mcron-configuration} object.
15870 This service type can be the target of a service extension that provides
15871 it additional job specifications (@pxref{Service Composition}). In
15872 other words, it is possible to define services that provide additional
15876 @deftp {Data Type} mcron-configuration
15877 Data type representing the configuration of mcron.
15880 @item @code{mcron} (default: @var{mcron})
15881 The mcron package to use.
15884 This is a list of gexps (@pxref{G-Expressions}), where each gexp
15885 corresponds to an mcron job specification (@pxref{Syntax, mcron job
15886 specifications,, mcron, GNU@tie{}mcron}).
15892 @subsection Log Rotation
15895 @cindex log rotation
15897 Log files such as those found in @file{/var/log} tend to grow endlessly,
15898 so it's a good idea to @dfn{rotate} them once in a while---i.e., archive
15899 their contents in separate files, possibly compressed. The @code{(gnu
15900 services admin)} module provides an interface to GNU@tie{}Rot[t]log, a
15901 log rotation tool (@pxref{Top,,, rottlog, GNU Rot[t]log Manual}).
15903 This service is part of @code{%base-services}, and thus enabled by
15904 default, with the default settings, for commonly encountered log files.
15905 The example below shows how to extend it with an additional
15906 @dfn{rotation}, should you need to do that (usually, services that
15907 produce log files already take care of that):
15910 (use-modules (guix) (gnu))
15911 (use-service-modules admin)
15913 (define my-log-files
15914 ;; Log files that I want to rotate.
15915 '("/var/log/something.log" "/var/log/another.log"))
15919 (services (cons (simple-service 'rotate-my-stuff
15920 rottlog-service-type
15921 (list (log-rotation
15923 (files my-log-files))))
15927 @defvr {Scheme Variable} rottlog-service-type
15928 This is the type of the Rottlog service, whose value is a
15929 @code{rottlog-configuration} object.
15931 Other services can extend this one with new @code{log-rotation} objects
15932 (see below), thereby augmenting the set of files to be rotated.
15934 This service type can define mcron jobs (@pxref{Scheduled Job
15935 Execution}) to run the rottlog service.
15938 @deftp {Data Type} rottlog-configuration
15939 Data type representing the configuration of rottlog.
15942 @item @code{rottlog} (default: @code{rottlog})
15943 The Rottlog package to use.
15945 @item @code{rc-file} (default: @code{(file-append rottlog "/etc/rc")})
15946 The Rottlog configuration file to use (@pxref{Mandatory RC Variables,,,
15947 rottlog, GNU Rot[t]log Manual}).
15949 @item @code{rotations} (default: @code{%default-rotations})
15950 A list of @code{log-rotation} objects as defined below.
15953 This is a list of gexps where each gexp corresponds to an mcron job
15954 specification (@pxref{Scheduled Job Execution}).
15958 @deftp {Data Type} log-rotation
15959 Data type representing the rotation of a group of log files.
15961 Taking an example from the Rottlog manual (@pxref{Period Related File
15962 Examples,,, rottlog, GNU Rot[t]log Manual}), a log rotation might be
15968 (files '("/var/log/apache/*"))
15969 (options '("storedir apache-archives"
15975 The list of fields is as follows:
15978 @item @code{frequency} (default: @code{'weekly})
15979 The log rotation frequency, a symbol.
15982 The list of files or file glob patterns to rotate.
15984 @item @code{options} (default: @code{'()})
15985 The list of rottlog options for this rotation (@pxref{Configuration
15986 parameters,,, rottlog, GNU Rot[t]lg Manual}).
15988 @item @code{post-rotate} (default: @code{#f})
15989 Either @code{#f} or a gexp to execute once the rotation has completed.
15993 @defvr {Scheme Variable} %default-rotations
15994 Specifies weekly rotation of @code{%rotated-files} and of
15995 @file{/var/log/guix-daemon.log}.
15998 @defvr {Scheme Variable} %rotated-files
15999 The list of syslog-controlled files to be rotated. By default it is:
16000 @code{'("/var/log/messages" "/var/log/secure" "/var/log/debug" \
16001 "/var/log/maillog")}.
16004 @node Networking Services
16005 @subsection Networking Services
16007 The @code{(gnu services networking)} module provides services to configure
16008 the network interface.
16010 @cindex DHCP, networking service
16011 @defvr {Scheme Variable} dhcp-client-service-type
16012 This is the type of services that run @var{dhcp}, a Dynamic Host Configuration
16013 Protocol (DHCP) client, on all the non-loopback network interfaces. Its value
16014 is the DHCP client package to use, @code{isc-dhcp} by default.
16017 @deffn {Scheme Procedure} dhcpd-service-type
16018 This type defines a service that runs a DHCP daemon. To create a
16019 service of this type, you must supply a @code{<dhcpd-configuration>}.
16023 (service dhcpd-service-type
16024 (dhcpd-configuration
16025 (config-file (local-file "my-dhcpd.conf"))
16026 (interfaces '("enp0s25"))))
16030 @deftp {Data Type} dhcpd-configuration
16032 @item @code{package} (default: @code{isc-dhcp})
16033 The package that provides the DHCP daemon. This package is expected to
16034 provide the daemon at @file{sbin/dhcpd} relative to its output
16035 directory. The default package is the
16036 @uref{https://www.isc.org/products/DHCP, ISC's DHCP server}.
16037 @item @code{config-file} (default: @code{#f})
16038 The configuration file to use. This is required. It will be passed to
16039 @code{dhcpd} via its @code{-cf} option. This may be any ``file-like''
16040 object (@pxref{G-Expressions, file-like objects}). See @code{man
16041 dhcpd.conf} for details on the configuration file syntax.
16042 @item @code{version} (default: @code{"4"})
16043 The DHCP version to use. The ISC DHCP server supports the values ``4'',
16044 ``6'', and ``4o6''. These correspond to the @code{dhcpd} program
16045 options @code{-4}, @code{-6}, and @code{-4o6}. See @code{man dhcpd} for
16047 @item @code{run-directory} (default: @code{"/run/dhcpd"})
16048 The run directory to use. At service activation time, this directory
16049 will be created if it does not exist.
16050 @item @code{pid-file} (default: @code{"/run/dhcpd/dhcpd.pid"})
16051 The PID file to use. This corresponds to the @code{-pf} option of
16052 @code{dhcpd}. See @code{man dhcpd} for details.
16053 @item @code{interfaces} (default: @code{'()})
16054 The names of the network interfaces on which dhcpd should listen for
16055 broadcasts. If this list is not empty, then its elements (which must be
16056 strings) will be appended to the @code{dhcpd} invocation when starting
16057 the daemon. It may not be necessary to explicitly specify any
16058 interfaces here; see @code{man dhcpd} for details.
16062 @defvr {Scheme Variable} static-networking-service-type
16063 This is the type for statically-configured network interfaces.
16064 @c TODO Document <static-networking> data structures.
16067 @deffn {Scheme Procedure} static-networking-service @var{interface} @var{ip} @
16068 [#:netmask #f] [#:gateway #f] [#:name-servers @code{'()}] @
16069 [#:requirement @code{'(udev)}]
16070 Return a service that starts @var{interface} with address @var{ip}. If
16071 @var{netmask} is true, use it as the network mask. If @var{gateway} is true,
16072 it must be a string specifying the default network gateway. @var{requirement}
16073 can be used to declare a dependency on another service before configuring the
16076 This procedure can be called several times, one for each network
16077 interface of interest. Behind the scenes what it does is extend
16078 @code{static-networking-service-type} with additional network interfaces
16084 (static-networking-service "eno1" "192.168.1.82"
16085 #:gateway "192.168.1.2"
16086 #:name-servers '("192.168.1.2"))
16093 @cindex network management
16094 @deffn {Scheme Procedure} wicd-service [#:wicd @var{wicd}]
16095 Return a service that runs @url{https://launchpad.net/wicd,Wicd}, a network
16096 management daemon that aims to simplify wired and wireless networking.
16098 This service adds the @var{wicd} package to the global profile, providing
16099 several commands to interact with the daemon and configure networking:
16100 @command{wicd-client}, a graphical user interface, and the @command{wicd-cli}
16101 and @command{wicd-curses} user interfaces.
16104 @cindex ModemManager
16106 @defvr {Scheme Variable} modem-manager-service-type
16107 This is the service type for the
16108 @uref{https://wiki.gnome.org/Projects/ModemManager, ModemManager}
16109 service. The value for this service type is a
16110 @code{modem-manager-configuration} record.
16112 This service is part of @code{%desktop-services} (@pxref{Desktop
16116 @deftp {Data Type} modem-manager-configuration
16117 Data type representing the configuration of ModemManager.
16120 @item @code{modem-manager} (default: @code{modem-manager})
16121 The ModemManager package to use.
16126 @cindex USB_ModeSwitch
16127 @cindex Modeswitching
16129 @defvr {Scheme Variable} usb-modeswitch-service-type
16130 This is the service type for the
16131 @uref{https://www.draisberghof.de/usb_modeswitch/, USB_ModeSwitch}
16132 service. The value for this service type is
16133 a @code{usb-modeswitch-configuration} record.
16135 When plugged in, some USB modems (and other USB devices) initially present
16136 themselves as a read-only storage medium and not as a modem. They need to be
16137 @dfn{modeswitched} before they are usable. The USB_ModeSwitch service type
16138 installs udev rules to automatically modeswitch these devices when they are
16141 This service is part of @code{%desktop-services} (@pxref{Desktop
16145 @deftp {Data Type} usb-modeswitch-configuration
16146 Data type representing the configuration of USB_ModeSwitch.
16149 @item @code{usb-modeswitch} (default: @code{usb-modeswitch})
16150 The USB_ModeSwitch package providing the binaries for modeswitching.
16152 @item @code{usb-modeswitch-data} (default: @code{usb-modeswitch-data})
16153 The package providing the device data and udev rules file used by
16156 @item @code{config-file} (default: @code{#~(string-append #$usb-modeswitch:dispatcher "/etc/usb_modeswitch.conf")})
16157 Which config file to use for the USB_ModeSwitch dispatcher. By default the
16158 config file shipped with USB_ModeSwitch is used which disables logging to
16159 @file{/var/log} among other default settings. If set to @code{#f}, no config
16165 @cindex NetworkManager
16167 @defvr {Scheme Variable} network-manager-service-type
16168 This is the service type for the
16169 @uref{https://wiki.gnome.org/Projects/NetworkManager, NetworkManager}
16170 service. The value for this service type is a
16171 @code{network-manager-configuration} record.
16173 This service is part of @code{%desktop-services} (@pxref{Desktop
16177 @deftp {Data Type} network-manager-configuration
16178 Data type representing the configuration of NetworkManager.
16181 @item @code{network-manager} (default: @code{network-manager})
16182 The NetworkManager package to use.
16184 @item @code{dns} (default: @code{"default"})
16185 Processing mode for DNS, which affects how NetworkManager uses the
16186 @code{resolv.conf} configuration file.
16190 NetworkManager will update @code{resolv.conf} to reflect the nameservers
16191 provided by currently active connections.
16194 NetworkManager will run @code{dnsmasq} as a local caching nameserver, using a
16195 @dfn{conditional forwarding} configuration if you are connected to a VPN, and
16196 then update @code{resolv.conf} to point to the local nameserver.
16198 With this setting, you can share your network connection. For example when
16199 you want to share your network connection to another laptop @i{via} an
16200 Ethernet cable, you can open @command{nm-connection-editor} and configure the
16201 Wired connection's method for IPv4 and IPv6 to be ``Shared to other computers''
16202 and reestablish the connection (or reboot).
16204 You can also set up a @dfn{host-to-guest connection} to QEMU VMs
16205 (@pxref{Installing Guix in a VM}). With a host-to-guest connection, you can
16206 e.g.@: access a Web server running on the VM (@pxref{Web Services}) from a Web
16207 browser on your host system, or connect to the VM @i{via} SSH
16208 (@pxref{Networking Services, @code{openssh-service-type}}). To set up a
16209 host-to-guest connection, run this command once:
16212 nmcli connection add type tun \
16213 connection.interface-name tap0 \
16214 tun.mode tap tun.owner $(id -u) \
16215 ipv4.method shared \
16216 ipv4.addresses 172.28.112.1/24
16219 Then each time you launch your QEMU VM (@pxref{Running Guix in a VM}), pass
16220 @option{-nic tap,ifname=tap0,script=no,downscript=no} to
16221 @command{qemu-system-...}.
16224 NetworkManager will not modify @code{resolv.conf}.
16227 @item @code{vpn-plugins} (default: @code{'()})
16228 This is the list of available plugins for virtual private networks
16229 (VPNs). An example of this is the @code{network-manager-openvpn}
16230 package, which allows NetworkManager to manage VPNs @i{via} OpenVPN.
16236 @deffn {Scheme Variable} connman-service-type
16237 This is the service type to run @url{https://01.org/connman,Connman},
16238 a network connection manager.
16240 Its value must be an
16241 @code{connman-configuration} record as in this example:
16244 (service connman-service-type
16245 (connman-configuration
16246 (disable-vpn? #t)))
16249 See below for details about @code{connman-configuration}.
16252 @deftp {Data Type} connman-configuration
16253 Data Type representing the configuration of connman.
16256 @item @code{connman} (default: @var{connman})
16257 The connman package to use.
16259 @item @code{disable-vpn?} (default: @code{#f})
16260 When true, disable connman's vpn plugin.
16264 @cindex WPA Supplicant
16265 @defvr {Scheme Variable} wpa-supplicant-service-type
16266 This is the service type to run @url{https://w1.fi/wpa_supplicant/,WPA
16267 supplicant}, an authentication daemon required to authenticate against
16268 encrypted WiFi or ethernet networks.
16271 @deftp {Data Type} wpa-supplicant-configuration
16272 Data type representing the configuration of WPA Supplicant.
16274 It takes the following parameters:
16277 @item @code{wpa-supplicant} (default: @code{wpa-supplicant})
16278 The WPA Supplicant package to use.
16280 @item @code{requirement} (default: @code{'(user-processes loopback syslogd)}
16281 List of services that should be started before WPA Supplicant starts.
16283 @item @code{dbus?} (default: @code{#t})
16284 Whether to listen for requests on D-Bus.
16286 @item @code{pid-file} (default: @code{"/var/run/wpa_supplicant.pid"})
16287 Where to store the PID file.
16289 @item @code{interface} (default: @code{#f})
16290 If this is set, it must specify the name of a network interface that
16291 WPA supplicant will control.
16293 @item @code{config-file} (default: @code{#f})
16294 Optional configuration file to use.
16296 @item @code{extra-options} (default: @code{'()})
16297 List of additional command-line arguments to pass to the daemon.
16301 @cindex hostapd service, for Wi-Fi access points
16302 @cindex Wi-Fi access points, hostapd service
16303 @defvr {Scheme Variable} hostapd-service-type
16304 This is the service type to run the @uref{https://w1.fi/hostapd/,
16305 hostapd} daemon to set up WiFi (IEEE 802.11) access points and
16306 authentication servers. Its associated value must be a
16307 @code{hostapd-configuration} as shown below:
16310 ;; Use wlan1 to run the access point for "My Network".
16311 (service hostapd-service-type
16312 (hostapd-configuration
16313 (interface "wlan1")
16314 (ssid "My Network")
16319 @deftp {Data Type} hostapd-configuration
16320 This data type represents the configuration of the hostapd service, with
16321 the following fields:
16324 @item @code{package} (default: @code{hostapd})
16325 The hostapd package to use.
16327 @item @code{interface} (default: @code{"wlan0"})
16328 The network interface to run the WiFi access point.
16331 The SSID (@dfn{service set identifier}), a string that identifies this
16334 @item @code{broadcast-ssid?} (default: @code{#t})
16335 Whether to broadcast this SSID.
16337 @item @code{channel} (default: @code{1})
16338 The WiFi channel to use.
16340 @item @code{driver} (default: @code{"nl80211"})
16341 The driver interface type. @code{"nl80211"} is used with all Linux
16342 mac80211 drivers. Use @code{"none"} if building hostapd as a standalone
16343 RADIUS server that does # not control any wireless/wired driver.
16345 @item @code{extra-settings} (default: @code{""})
16346 Extra settings to append as-is to the hostapd configuration file. See
16347 @uref{https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf} for the
16348 configuration file reference.
16352 @defvr {Scheme Variable} simulated-wifi-service-type
16353 This is the type of a service to simulate WiFi networking, which can be
16354 useful in virtual machines for testing purposes. The service loads the
16356 @uref{https://www.kernel.org/doc/html/latest/networking/mac80211_hwsim/mac80211_hwsim.html,
16357 @code{mac80211_hwsim} module} and starts hostapd to create a pseudo WiFi
16358 network that can be seen on @code{wlan0}, by default.
16360 The service's value is a @code{hostapd-configuration} record.
16364 @defvr {Scheme Variable} iptables-service-type
16365 This is the service type to set up an iptables configuration. iptables is a
16366 packet filtering framework supported by the Linux kernel. This service
16367 supports configuring iptables for both IPv4 and IPv6. A simple example
16368 configuration rejecting all incoming connections except those to the ssh port
16372 (service iptables-service-type
16373 (iptables-configuration
16374 (ipv4-rules (plain-file "iptables.rules" "*filter
16378 -A INPUT -p tcp --dport 22 -j ACCEPT
16379 -A INPUT -j REJECT --reject-with icmp-port-unreachable
16382 (ipv6-rules (plain-file "ip6tables.rules" "*filter
16386 -A INPUT -p tcp --dport 22 -j ACCEPT
16387 -A INPUT -j REJECT --reject-with icmp6-port-unreachable
16393 @deftp {Data Type} iptables-configuration
16394 The data type representing the configuration of iptables.
16397 @item @code{iptables} (default: @code{iptables})
16398 The iptables package that provides @code{iptables-restore} and
16399 @code{ip6tables-restore}.
16400 @item @code{ipv4-rules} (default: @code{%iptables-accept-all-rules})
16401 The iptables rules to use. It will be passed to @code{iptables-restore}.
16402 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16404 @item @code{ipv6-rules} (default: @code{%iptables-accept-all-rules})
16405 The ip6tables rules to use. It will be passed to @code{ip6tables-restore}.
16406 This may be any ``file-like'' object (@pxref{G-Expressions, file-like
16412 @defvr {Scheme Variable} nftables-service-type
16413 This is the service type to set up a nftables configuration. nftables is a
16414 netfilter project that aims to replace the existing iptables, ip6tables,
16415 arptables and ebtables framework. It provides a new packet filtering
16416 framework, a new user-space utility @command{nft}, and a compatibility layer
16417 for iptables. This service comes with a default ruleset
16418 @code{%default-nftables-ruleset} that rejecting all incomming connections
16419 except those to the ssh port 22. To use it, simply write:
16422 (service nftables-service-type)
16426 @deftp {Data Type} nftables-configuration
16427 The data type representing the configuration of nftables.
16430 @item @code{package} (default: @code{nftables})
16431 The nftables package that provides @command{nft}.
16432 @item @code{ruleset} (default: @code{%default-nftables-ruleset})
16433 The nftables ruleset to use. This may be any ``file-like'' object
16434 (@pxref{G-Expressions, file-like objects}).
16438 @cindex NTP (Network Time Protocol), service
16439 @cindex ntpd, service for the Network Time Protocol daemon
16440 @cindex real time clock
16441 @defvr {Scheme Variable} ntp-service-type
16442 This is the type of the service running the @uref{https://www.ntp.org,
16443 Network Time Protocol (NTP)} daemon, @command{ntpd}. The daemon will keep the
16444 system clock synchronized with that of the specified NTP servers.
16446 The value of this service is an @code{ntpd-configuration} object, as described
16450 @deftp {Data Type} ntp-configuration
16451 This is the data type for the NTP service configuration.
16454 @item @code{servers} (default: @code{%ntp-servers})
16455 This is the list of servers (@code{<ntp-server>} records) with which
16456 @command{ntpd} will be synchronized. See the @code{ntp-server} data type
16459 @item @code{allow-large-adjustment?} (default: @code{#t})
16460 This determines whether @command{ntpd} is allowed to make an initial
16461 adjustment of more than 1,000 seconds.
16463 @item @code{ntp} (default: @code{ntp})
16464 The NTP package to use.
16468 @defvr {Scheme Variable} %ntp-servers
16469 List of host names used as the default NTP servers. These are servers of the
16470 @uref{https://www.ntppool.org/en/, NTP Pool Project}.
16473 @deftp {Data Type} ntp-server
16474 The data type representing the configuration of a NTP server.
16477 @item @code{type} (default: @code{'server})
16478 The type of the NTP server, given as a symbol. One of @code{'pool},
16479 @code{'server}, @code{'peer}, @code{'broadcast} or @code{'manycastclient}.
16481 @item @code{address}
16482 The address of the server, as a string.
16484 @item @code{options}
16485 NTPD options to use with that specific server, given as a list of option names
16486 and/or of option names and values tuples. The following example define a server
16487 to use with the options @option{iburst} and @option{prefer}, as well as
16488 @option{version} 3 and a @option{maxpoll} time of 16 seconds.
16493 (address "some.ntp.server.org")
16494 (options `(iburst (version 3) (maxpoll 16) prefer))))
16500 @deffn {Scheme Procedure} openntpd-service-type
16501 Run the @command{ntpd}, the Network Time Protocol (NTP) daemon, as implemented
16502 by @uref{http://www.openntpd.org, OpenNTPD}. The daemon will keep the system
16503 clock synchronized with that of the given servers.
16507 openntpd-service-type
16508 (openntpd-configuration
16509 (listen-on '("127.0.0.1" "::1"))
16510 (sensor '("udcf0 correction 70000"))
16511 (constraint-from '("www.gnu.org"))
16512 (constraints-from '("https://www.google.com/"))))
16517 @defvr {Scheme Variable} %openntpd-servers
16518 This variable is a list of the server addresses defined in
16519 @code{%ntp-servers}.
16522 @deftp {Data Type} openntpd-configuration
16524 @item @code{openntpd} (default: @code{(file-append openntpd "/sbin/ntpd")})
16525 The openntpd executable to use.
16526 @item @code{listen-on} (default: @code{'("127.0.0.1" "::1")})
16527 A list of local IP addresses or hostnames the ntpd daemon should listen on.
16528 @item @code{query-from} (default: @code{'()})
16529 A list of local IP address the ntpd daemon should use for outgoing queries.
16530 @item @code{sensor} (default: @code{'()})
16531 Specify a list of timedelta sensor devices ntpd should use. @code{ntpd}
16532 will listen to each sensor that actually exists and ignore non-existent ones.
16533 See @uref{https://man.openbsd.org/ntpd.conf, upstream documentation} for more
16535 @item @code{server} (default: @code{'()})
16536 Specify a list of IP addresses or hostnames of NTP servers to synchronize to.
16537 @item @code{servers} (default: @code{%openntp-servers})
16538 Specify a list of IP addresses or hostnames of NTP pools to synchronize to.
16539 @item @code{constraint-from} (default: @code{'()})
16540 @code{ntpd} can be configured to query the ‘Date’ from trusted HTTPS servers via TLS.
16541 This time information is not used for precision but acts as an authenticated
16542 constraint, thereby reducing the impact of unauthenticated NTP
16543 man-in-the-middle attacks.
16544 Specify a list of URLs, IP addresses or hostnames of HTTPS servers to provide
16546 @item @code{constraints-from} (default: @code{'()})
16547 As with constraint from, specify a list of URLs, IP addresses or hostnames of
16548 HTTPS servers to provide a constraint. Should the hostname resolve to multiple
16549 IP addresses, @code{ntpd} will calculate a median constraint from all of them.
16554 @deffn {Scheme variable} inetd-service-type
16555 This service runs the @command{inetd} (@pxref{inetd invocation,,,
16556 inetutils, GNU Inetutils}) daemon. @command{inetd} listens for
16557 connections on internet sockets, and lazily starts the specified server
16558 program when a connection is made on one of these sockets.
16560 The value of this service is an @code{inetd-configuration} object. The
16561 following example configures the @command{inetd} daemon to provide the
16562 built-in @command{echo} service, as well as an smtp service which
16563 forwards smtp traffic over ssh to a server @code{smtp-server} behind a
16564 gateway @code{hostname}:
16569 (inetd-configuration
16573 (socket-type 'stream)
16580 (socket-type 'stream)
16584 (program (file-append openssh "/bin/ssh"))
16586 '("ssh" "-qT" "-i" "/path/to/ssh_key"
16587 "-W" "smtp-server:25" "user@@hostname")))))))
16590 See below for more details about @code{inetd-configuration}.
16593 @deftp {Data Type} inetd-configuration
16594 Data type representing the configuration of @command{inetd}.
16597 @item @code{program} (default: @code{(file-append inetutils "/libexec/inetd")})
16598 The @command{inetd} executable to use.
16600 @item @code{entries} (default: @code{'()})
16601 A list of @command{inetd} service entries. Each entry should be created
16602 by the @code{inetd-entry} constructor.
16606 @deftp {Data Type} inetd-entry
16607 Data type representing an entry in the @command{inetd} configuration.
16608 Each entry corresponds to a socket where @command{inetd} will listen for
16612 @item @code{node} (default: @code{#f})
16613 Optional string, a comma-separated list of local addresses
16614 @command{inetd} should use when listening for this service.
16615 @xref{Configuration file,,, inetutils, GNU Inetutils} for a complete
16616 description of all options.
16618 A string, the name must correspond to an entry in @code{/etc/services}.
16619 @item @code{socket-type}
16620 One of @code{'stream}, @code{'dgram}, @code{'raw}, @code{'rdm} or
16622 @item @code{protocol}
16623 A string, must correspond to an entry in @code{/etc/protocols}.
16624 @item @code{wait?} (default: @code{#t})
16625 Whether @command{inetd} should wait for the server to exit before
16626 listening to new service requests.
16628 A string containing the user (and, optionally, group) name of the user
16629 as whom the server should run. The group name can be specified in a
16630 suffix, separated by a colon or period, i.e.@: @code{"user"},
16631 @code{"user:group"} or @code{"user.group"}.
16632 @item @code{program} (default: @code{"internal"})
16633 The server program which will serve the requests, or @code{"internal"}
16634 if @command{inetd} should use a built-in service.
16635 @item @code{arguments} (default: @code{'()})
16636 A list strings or file-like objects, which are the server program's
16637 arguments, starting with the zeroth argument, i.e.@: the name of the
16638 program itself. For @command{inetd}'s internal services, this entry
16639 must be @code{'()} or @code{'("internal")}.
16642 @xref{Configuration file,,, inetutils, GNU Inetutils} for a more
16643 detailed discussion of each configuration field.
16647 @defvr {Scheme Variable} tor-service-type
16648 This is the type for a service that runs the @uref{https://torproject.org,
16649 Tor} anonymous networking daemon. The service is configured using a
16650 @code{<tor-configuration>} record. By default, the Tor daemon runs as the
16651 @code{tor} unprivileged user, which is a member of the @code{tor} group.
16655 @deftp {Data Type} tor-configuration
16657 @item @code{tor} (default: @code{tor})
16658 The package that provides the Tor daemon. This package is expected to provide
16659 the daemon at @file{bin/tor} relative to its output directory. The default
16660 package is the @uref{https://www.torproject.org, Tor Project's}
16663 @item @code{config-file} (default: @code{(plain-file "empty" "")})
16664 The configuration file to use. It will be appended to a default configuration
16665 file, and the final configuration file will be passed to @code{tor} via its
16666 @code{-f} option. This may be any ``file-like'' object (@pxref{G-Expressions,
16667 file-like objects}). See @code{man tor} for details on the configuration file
16670 @item @code{hidden-services} (default: @code{'()})
16671 The list of @code{<hidden-service>} records to use. For any hidden service
16672 you include in this list, appropriate configuration to enable the hidden
16673 service will be automatically added to the default configuration file. You
16674 may conveniently create @code{<hidden-service>} records using the
16675 @code{tor-hidden-service} procedure described below.
16677 @item @code{socks-socket-type} (default: @code{'tcp})
16678 The default socket type that Tor should use for its SOCKS socket. This must
16679 be either @code{'tcp} or @code{'unix}. If it is @code{'tcp}, then by default
16680 Tor will listen on TCP port 9050 on the loopback interface (i.e., localhost).
16681 If it is @code{'unix}, then Tor will listen on the UNIX domain socket
16682 @file{/var/run/tor/socks-sock}, which will be made writable by members of the
16685 If you want to customize the SOCKS socket in more detail, leave
16686 @code{socks-socket-type} at its default value of @code{'tcp} and use
16687 @code{config-file} to override the default by providing your own
16688 @code{SocksPort} option.
16690 @item @code{control-socket?} (default: @code{#f})
16691 Whether or not to provide a ``control socket'' by which Tor can be
16692 controlled to, for instance, dynamically instantiate tor onion services.
16693 If @code{#t}, Tor will listen for control commands on the UNIX domain socket
16694 @file{/var/run/tor/control-sock}, which will be made writable by members of the
16700 @cindex hidden service
16701 @deffn {Scheme Procedure} tor-hidden-service @var{name} @var{mapping}
16702 Define a new Tor @dfn{hidden service} called @var{name} and implementing
16703 @var{mapping}. @var{mapping} is a list of port/host tuples, such as:
16706 '((22 "127.0.0.1:22")
16707 (80 "127.0.0.1:8080"))
16710 In this example, port 22 of the hidden service is mapped to local port 22, and
16711 port 80 is mapped to local port 8080.
16713 This creates a @file{/var/lib/tor/hidden-services/@var{name}} directory, where
16714 the @file{hostname} file contains the @code{.onion} host name for the hidden
16717 See @uref{https://www.torproject.org/docs/tor-hidden-service.html.en, the Tor
16718 project's documentation} for more information.
16721 The @code{(gnu services rsync)} module provides the following services:
16723 You might want an rsync daemon if you have files that you want available
16724 so anyone (or just yourself) can download existing files or upload new
16727 @deffn {Scheme Variable} rsync-service-type
16728 This is the service type for the @uref{https://rsync.samba.org, rsync} daemon,
16729 The value for this service type is a
16730 @command{rsync-configuration} record as in this example:
16733 (service rsync-service-type)
16736 See below for details about @code{rsync-configuration}.
16739 @deftp {Data Type} rsync-configuration
16740 Data type representing the configuration for @code{rsync-service}.
16743 @item @code{package} (default: @var{rsync})
16744 @code{rsync} package to use.
16746 @item @code{port-number} (default: @code{873})
16747 TCP port on which @command{rsync} listens for incoming connections. If port
16748 is less than @code{1024} @command{rsync} needs to be started as the
16749 @code{root} user and group.
16751 @item @code{pid-file} (default: @code{"/var/run/rsyncd/rsyncd.pid"})
16752 Name of the file where @command{rsync} writes its PID.
16754 @item @code{lock-file} (default: @code{"/var/run/rsyncd/rsyncd.lock"})
16755 Name of the file where @command{rsync} writes its lock file.
16757 @item @code{log-file} (default: @code{"/var/log/rsyncd.log"})
16758 Name of the file where @command{rsync} writes its log file.
16760 @item @code{use-chroot?} (default: @var{#t})
16761 Whether to use chroot for @command{rsync} shared directory.
16763 @item @code{share-path} (default: @file{/srv/rsync})
16764 Location of the @command{rsync} shared directory.
16766 @item @code{share-comment} (default: @code{"Rsync share"})
16767 Comment of the @command{rsync} shared directory.
16769 @item @code{read-only?} (default: @var{#f})
16770 Read-write permissions to shared directory.
16772 @item @code{timeout} (default: @code{300})
16773 I/O timeout in seconds.
16775 @item @code{user} (default: @var{"root"})
16776 Owner of the @code{rsync} process.
16778 @item @code{group} (default: @var{"root"})
16779 Group of the @code{rsync} process.
16781 @item @code{uid} (default: @var{"rsyncd"})
16782 User name or user ID that file transfers to and from that module should take
16783 place as when the daemon was run as @code{root}.
16785 @item @code{gid} (default: @var{"rsyncd"})
16786 Group name or group ID that will be used when accessing the module.
16791 The @code{(gnu services syncthing)} module provides the following services:
16794 You might want a syncthing daemon if you have files between two or more
16795 computers and want to sync them in real time, safely protected from
16798 @deffn {Scheme Variable} syncthing-service-type
16799 This is the service type for the @uref{https://syncthing.net/,
16800 syncthing} daemon, The value for this service type is a
16801 @command{syncthing-configuration} record as in this example:
16804 (service syncthing-service-type
16805 (syncthing-configuration (user "alice")))
16808 See below for details about @code{syncthing-configuration}.
16810 @deftp {Data Type} syncthing-configuration
16811 Data type representing the configuration for @code{syncthing-service-type}.
16814 @item @code{syncthing} (default: @var{syncthing})
16815 @code{syncthing} package to use.
16817 @item @code{arguments} (default: @var{'()})
16818 List of command-line arguments passing to @code{syncthing} binary.
16820 @item @code{logflags} (default: @var{0})
16821 Sum of loging flags, see
16822 @uref{https://docs.syncthing.net/users/syncthing.html#cmdoption-logflags, Syncthing documentation logflags}.
16824 @item @code{user} (default: @var{#f})
16825 The user as which the Syncthing service is to be run.
16826 This assumes that the specified user exists.
16828 @item @code{group} (default: @var{"users"})
16829 The group as which the Syncthing service is to be run.
16830 This assumes that the specified group exists.
16832 @item @code{home} (default: @var{#f})
16833 Common configuration and data directory. The default configuration
16834 directory is @file{$HOME} of the specified Syncthing @code{user}.
16840 Furthermore, @code{(gnu services ssh)} provides the following services.
16844 @deffn {Scheme Procedure} lsh-service [#:host-key "/etc/lsh/host-key"] @
16845 [#:daemonic? #t] [#:interfaces '()] [#:port-number 22] @
16846 [#:allow-empty-passwords? #f] [#:root-login? #f] @
16847 [#:syslog-output? #t] [#:x11-forwarding? #t] @
16848 [#:tcp/ip-forwarding? #t] [#:password-authentication? #t] @
16849 [#:public-key-authentication? #t] [#:initialize? #t]
16850 Run the @command{lshd} program from @var{lsh} to listen on port @var{port-number}.
16851 @var{host-key} must designate a file containing the host key, and readable
16854 When @var{daemonic?} is true, @command{lshd} will detach from the
16855 controlling terminal and log its output to syslogd, unless one sets
16856 @var{syslog-output?} to false. Obviously, it also makes lsh-service
16857 depend on existence of syslogd service. When @var{pid-file?} is true,
16858 @command{lshd} writes its PID to the file called @var{pid-file}.
16860 When @var{initialize?} is true, automatically create the seed and host key
16861 upon service activation if they do not exist yet. This may take long and
16862 require interaction.
16864 When @var{initialize?} is false, it is up to the user to initialize the
16865 randomness generator (@pxref{lsh-make-seed,,, lsh, LSH Manual}), and to create
16866 a key pair with the private key stored in file @var{host-key} (@pxref{lshd
16867 basics,,, lsh, LSH Manual}).
16869 When @var{interfaces} is empty, lshd listens for connections on all the
16870 network interfaces; otherwise, @var{interfaces} must be a list of host names
16873 @var{allow-empty-passwords?} specifies whether to accept log-ins with empty
16874 passwords, and @var{root-login?} specifies whether to accept log-ins as
16877 The other options should be self-descriptive.
16882 @deffn {Scheme Variable} openssh-service-type
16883 This is the type for the @uref{http://www.openssh.org, OpenSSH} secure
16884 shell daemon, @command{sshd}. Its value must be an
16885 @code{openssh-configuration} record as in this example:
16888 (service openssh-service-type
16889 (openssh-configuration
16890 (x11-forwarding? #t)
16891 (permit-root-login 'without-password)
16893 `(("alice" ,(local-file "alice.pub"))
16894 ("bob" ,(local-file "bob.pub"))))))
16897 See below for details about @code{openssh-configuration}.
16899 This service can be extended with extra authorized keys, as in this
16903 (service-extension openssh-service-type
16904 (const `(("charlie"
16905 ,(local-file "charlie.pub")))))
16909 @deftp {Data Type} openssh-configuration
16910 This is the configuration record for OpenSSH's @command{sshd}.
16913 @item @code{openssh} (default @var{openssh})
16914 The Openssh package to use.
16916 @item @code{pid-file} (default: @code{"/var/run/sshd.pid"})
16917 Name of the file where @command{sshd} writes its PID.
16919 @item @code{port-number} (default: @code{22})
16920 TCP port on which @command{sshd} listens for incoming connections.
16922 @item @code{permit-root-login} (default: @code{#f})
16923 This field determines whether and when to allow logins as root. If
16924 @code{#f}, root logins are disallowed; if @code{#t}, they are allowed.
16925 If it's the symbol @code{'without-password}, then root logins are
16926 permitted but not with password-based authentication.
16928 @item @code{allow-empty-passwords?} (default: @code{#f})
16929 When true, users with empty passwords may log in. When false, they may
16932 @item @code{password-authentication?} (default: @code{#t})
16933 When true, users may log in with their password. When false, they have
16934 other authentication methods.
16936 @item @code{public-key-authentication?} (default: @code{#t})
16937 When true, users may log in using public key authentication. When
16938 false, users have to use other authentication method.
16940 Authorized public keys are stored in @file{~/.ssh/authorized_keys}.
16941 This is used only by protocol version 2.
16943 @item @code{x11-forwarding?} (default: @code{#f})
16944 When true, forwarding of X11 graphical client connections is
16945 enabled---in other words, @command{ssh} options @option{-X} and
16946 @option{-Y} will work.
16948 @item @code{allow-agent-forwarding?} (default: @code{#t})
16949 Whether to allow agent forwarding.
16951 @item @code{allow-tcp-forwarding?} (default: @code{#t})
16952 Whether to allow TCP forwarding.
16954 @item @code{gateway-ports?} (default: @code{#f})
16955 Whether to allow gateway ports.
16957 @item @code{challenge-response-authentication?} (default: @code{#f})
16958 Specifies whether challenge response authentication is allowed (e.g.@: via
16961 @item @code{use-pam?} (default: @code{#t})
16962 Enables the Pluggable Authentication Module interface. If set to
16963 @code{#t}, this will enable PAM authentication using
16964 @code{challenge-response-authentication?} and
16965 @code{password-authentication?}, in addition to PAM account and session
16966 module processing for all authentication types.
16968 Because PAM challenge response authentication usually serves an
16969 equivalent role to password authentication, you should disable either
16970 @code{challenge-response-authentication?} or
16971 @code{password-authentication?}.
16973 @item @code{print-last-log?} (default: @code{#t})
16974 Specifies whether @command{sshd} should print the date and time of the
16975 last user login when a user logs in interactively.
16977 @item @code{subsystems} (default: @code{'(("sftp" "internal-sftp"))})
16978 Configures external subsystems (e.g.@: file transfer daemon).
16980 This is a list of two-element lists, each of which containing the
16981 subsystem name and a command (with optional arguments) to execute upon
16984 The command @command{internal-sftp} implements an in-process SFTP
16985 server. Alternatively, one can specify the @command{sftp-server} command:
16987 (service openssh-service-type
16988 (openssh-configuration
16990 `(("sftp" ,(file-append openssh "/libexec/sftp-server"))))))
16993 @item @code{accepted-environment} (default: @code{'()})
16994 List of strings describing which environment variables may be exported.
16996 Each string gets on its own line. See the @code{AcceptEnv} option in
16997 @code{man sshd_config}.
16999 This example allows ssh-clients to export the @env{COLORTERM} variable.
17000 It is set by terminal emulators, which support colors. You can use it in
17001 your shell's resource file to enable colors for the prompt and commands
17002 if this variable is set.
17005 (service openssh-service-type
17006 (openssh-configuration
17007 (accepted-environment '("COLORTERM"))))
17010 @item @code{authorized-keys} (default: @code{'()})
17011 @cindex authorized keys, SSH
17012 @cindex SSH authorized keys
17013 This is the list of authorized keys. Each element of the list is a user
17014 name followed by one or more file-like objects that represent SSH public
17018 (openssh-configuration
17020 `(("rekado" ,(local-file "rekado.pub"))
17021 ("chris" ,(local-file "chris.pub"))
17022 ("root" ,(local-file "rekado.pub") ,(local-file "chris.pub")))))
17026 registers the specified public keys for user accounts @code{rekado},
17027 @code{chris}, and @code{root}.
17029 Additional authorized keys can be specified @i{via}
17030 @code{service-extension}.
17032 Note that this does @emph{not} interfere with the use of
17033 @file{~/.ssh/authorized_keys}.
17035 @item @code{log-level} (default: @code{'info})
17036 This is a symbol specifying the logging level: @code{quiet}, @code{fatal},
17037 @code{error}, @code{info}, @code{verbose}, @code{debug}, etc. See the man
17038 page for @file{sshd_config} for the full list of level names.
17040 @item @code{extra-content} (default: @code{""})
17041 This field can be used to append arbitrary text to the configuration file. It
17042 is especially useful for elaborate configurations that cannot be expressed
17043 otherwise. This configuration, for example, would generally disable root
17044 logins, but permit them from one specific IP address:
17047 (openssh-configuration
17049 Match Address 192.168.0.1
17050 PermitRootLogin yes"))
17056 @deffn {Scheme Procedure} dropbear-service [@var{config}]
17057 Run the @uref{https://matt.ucc.asn.au/dropbear/dropbear.html,Dropbear SSH
17058 daemon} with the given @var{config}, a @code{<dropbear-configuration>}
17061 For example, to specify a Dropbear service listening on port 1234, add
17062 this call to the operating system's @code{services} field:
17065 (dropbear-service (dropbear-configuration
17066 (port-number 1234)))
17070 @deftp {Data Type} dropbear-configuration
17071 This data type represents the configuration of a Dropbear SSH daemon.
17074 @item @code{dropbear} (default: @var{dropbear})
17075 The Dropbear package to use.
17077 @item @code{port-number} (default: 22)
17078 The TCP port where the daemon waits for incoming connections.
17080 @item @code{syslog-output?} (default: @code{#t})
17081 Whether to enable syslog output.
17083 @item @code{pid-file} (default: @code{"/var/run/dropbear.pid"})
17084 File name of the daemon's PID file.
17086 @item @code{root-login?} (default: @code{#f})
17087 Whether to allow @code{root} logins.
17089 @item @code{allow-empty-passwords?} (default: @code{#f})
17090 Whether to allow empty passwords.
17092 @item @code{password-authentication?} (default: @code{#t})
17093 Whether to enable password-based authentication.
17098 @deffn {Scheme Variable} autossh-service-type
17099 This is the type for the @uref{https://www.harding.motd.ca/autossh,
17100 AutoSSH} program that runs a copy of @command{ssh} and monitors it,
17101 restarting it as necessary should it die or stop passing traffic.
17102 AutoSSH can be run manually from the command-line by passing arguments
17103 to the binary @command{autossh} from the package @code{autossh}, but it
17104 can also be run as a Guix service. This latter use case is documented
17107 AutoSSH can be used to forward local traffic to a remote machine using
17108 an SSH tunnel, and it respects the @file{~/.ssh/config} of the user it
17111 For example, to specify a service running autossh as the user
17112 @code{pino} and forwarding all local connections to port @code{8081} to
17113 @code{remote:8081} using an SSH tunnel, add this call to the operating
17114 system's @code{services} field:
17117 (service autossh-service-type
17118 (autossh-configuration
17120 (ssh-options (list "-T" "-N" "-L" "8081:localhost:8081" "remote.net"))))
17124 @deftp {Data Type} autossh-configuration
17125 This data type represents the configuration of an AutoSSH service.
17129 @item @code{user} (default @code{"autossh"})
17130 The user as which the AutoSSH service is to be run.
17131 This assumes that the specified user exists.
17133 @item @code{poll} (default @code{600})
17134 Specifies the connection poll time in seconds.
17136 @item @code{first-poll} (default @code{#f})
17137 Specifies how many seconds AutoSSH waits before the first connection
17138 test. After this first test, polling is resumed at the pace defined in
17139 @code{poll}. When set to @code{#f}, the first poll is not treated
17140 specially and will also use the connection poll specified in
17143 @item @code{gate-time} (default @code{30})
17144 Specifies how many seconds an SSH connection must be active before it is
17145 considered successful.
17147 @item @code{log-level} (default @code{1})
17148 The log level, corresponding to the levels used by syslog---so @code{0}
17149 is the most silent while @code{7} is the chattiest.
17151 @item @code{max-start} (default @code{#f})
17152 The maximum number of times SSH may be (re)started before AutoSSH exits.
17153 When set to @code{#f}, no maximum is configured and AutoSSH may restart indefinitely.
17155 @item @code{message} (default @code{""})
17156 The message to append to the echo message sent when testing connections.
17158 @item @code{port} (default @code{"0"})
17159 The ports used for monitoring the connection. When set to @code{"0"},
17160 monitoring is disabled. When set to @code{"@var{n}"} where @var{n} is
17161 a positive integer, ports @var{n} and @var{n}+1 are used for
17162 monitoring the connection, such that port @var{n} is the base
17163 monitoring port and @code{n+1} is the echo port. When set to
17164 @code{"@var{n}:@var{m}"} where @var{n} and @var{m} are positive
17165 integers, the ports @var{n} and @var{m} are used for monitoring the
17166 connection, such that port @var{n} is the base monitoring port and
17167 @var{m} is the echo port.
17169 @item @code{ssh-options} (default @code{'()})
17170 The list of command-line arguments to pass to @command{ssh} when it is
17171 run. Options @option{-f} and @option{-M} are reserved for AutoSSH and
17172 may cause undefined behaviour.
17178 @deffn {Scheme Variable} webssh-service-type
17179 This is the type for the @uref{https://webssh.huashengdun.org/, WebSSH}
17180 program that runs a web SSH client. WebSSH can be run manually from the
17181 command-line by passing arguments to the binary @command{wssh} from the
17182 package @code{webssh}, but it can also be run as a Guix service. This
17183 latter use case is documented here.
17185 For example, to specify a service running WebSSH on loopback interface
17186 on port @code{8888} with reject policy with a list of allowed to
17187 connection hosts, and NGINX as a reverse-proxy to this service listening
17188 for HTTPS connection, add this call to the operating system's
17189 @code{services} field:
17192 (service webssh-service-type
17193 (webssh-configuration (address "127.0.0.1")
17196 (known-hosts '("localhost ecdsa-sha2-nistp256 AAAA…"
17197 "127.0.0.1 ecdsa-sha2-nistp256 AAAA…"))))
17199 (service nginx-service-type
17200 (nginx-configuration
17203 (nginx-server-configuration
17204 (inherit %webssh-configuration-nginx)
17205 (server-name '("webssh.example.com"))
17206 (listen '("443 ssl"))
17207 (ssl-certificate (letsencrypt-certificate "webssh.example.com"))
17208 (ssl-certificate-key (letsencrypt-key "webssh.example.com"))
17210 (cons (nginx-location-configuration
17211 (uri "/.well-known")
17212 (body '("root /var/www;")))
17213 (nginx-server-configuration-locations %webssh-configuration-nginx))))))))
17217 @deftp {Data Type} webssh-configuration
17218 Data type representing the configuration for @code{webssh-service}.
17221 @item @code{package} (default: @var{webssh})
17222 @code{webssh} package to use.
17224 @item @code{user-name} (default: @var{"webssh"})
17225 User name or user ID that file transfers to and from that module should take
17228 @item @code{group-name} (default: @var{"webssh"})
17229 Group name or group ID that will be used when accessing the module.
17231 @item @code{address} (default: @var{#f})
17232 IP address on which @command{webssh} listens for incoming connections.
17234 @item @code{port} (default: @var{8888})
17235 TCP port on which @command{webssh} listens for incoming connections.
17237 @item @code{policy} (default: @var{#f})
17238 Connection policy. @var{reject} policy requires to specify @var{known-hosts}.
17240 @item @code{known-hosts} (default: @var{'()})
17241 List of hosts which allowed for SSH connection from @command{webssh}.
17243 @item @code{log-file} (default: @file{"/var/log/webssh.log"})
17244 Name of the file where @command{webssh} writes its log file.
17246 @item @code{log-level} (default: @var{#f})
17252 @defvr {Scheme Variable} %facebook-host-aliases
17253 This variable contains a string for use in @file{/etc/hosts}
17254 (@pxref{Host Names,,, libc, The GNU C Library Reference Manual}). Each
17255 line contains a entry that maps a known server name of the Facebook
17256 on-line service---e.g., @code{www.facebook.com}---to the local
17257 host---@code{127.0.0.1} or its IPv6 equivalent, @code{::1}.
17259 This variable is typically used in the @code{hosts-file} field of an
17260 @code{operating-system} declaration (@pxref{operating-system Reference,
17261 @file{/etc/hosts}}):
17264 (use-modules (gnu) (guix))
17267 (host-name "mymachine")
17270 ;; Create a /etc/hosts file with aliases for "localhost"
17271 ;; and "mymachine", as well as for Facebook servers.
17272 (plain-file "hosts"
17273 (string-append (local-host-aliases host-name)
17274 %facebook-host-aliases))))
17277 This mechanism can prevent programs running locally, such as Web
17278 browsers, from accessing Facebook.
17281 The @code{(gnu services avahi)} provides the following definition.
17283 @defvr {Scheme Variable} avahi-service-type
17284 This is the service that runs @command{avahi-daemon}, a system-wide
17285 mDNS/DNS-SD responder that allows for service discovery and
17286 ``zero-configuration'' host name lookups (see @uref{https://avahi.org/}).
17287 Its value must be an @code{avahi-configuration} record---see below.
17289 This service extends the name service cache daemon (nscd) so that it can
17290 resolve @code{.local} host names using
17291 @uref{https://0pointer.de/lennart/projects/nss-mdns/, nss-mdns}. @xref{Name
17292 Service Switch}, for information on host name resolution.
17294 Additionally, add the @var{avahi} package to the system profile so that
17295 commands such as @command{avahi-browse} are directly usable.
17298 @deftp {Data Type} avahi-configuration
17299 Data type representation the configuration for Avahi.
17303 @item @code{host-name} (default: @code{#f})
17304 If different from @code{#f}, use that as the host name to
17305 publish for this machine; otherwise, use the machine's actual host name.
17307 @item @code{publish?} (default: @code{#t})
17308 When true, allow host names and services to be published (broadcast) over the
17311 @item @code{publish-workstation?} (default: @code{#t})
17312 When true, @command{avahi-daemon} publishes the machine's host name and IP
17313 address via mDNS on the local network. To view the host names published on
17314 your local network, you can run:
17317 avahi-browse _workstation._tcp
17320 @item @code{wide-area?} (default: @code{#f})
17321 When true, DNS-SD over unicast DNS is enabled.
17323 @item @code{ipv4?} (default: @code{#t})
17324 @itemx @code{ipv6?} (default: @code{#t})
17325 These fields determine whether to use IPv4/IPv6 sockets.
17327 @item @code{domains-to-browse} (default: @code{'()})
17328 This is a list of domains to browse.
17332 @deffn {Scheme Variable} openvswitch-service-type
17333 This is the type of the @uref{https://www.openvswitch.org, Open vSwitch}
17334 service, whose value should be an @code{openvswitch-configuration}
17338 @deftp {Data Type} openvswitch-configuration
17339 Data type representing the configuration of Open vSwitch, a multilayer
17340 virtual switch which is designed to enable massive network automation
17341 through programmatic extension.
17344 @item @code{package} (default: @var{openvswitch})
17345 Package object of the Open vSwitch.
17350 @defvr {Scheme Variable} pagekite-service-type
17351 This is the service type for the @uref{https://pagekite.net, PageKite} service,
17352 a tunneling solution for making localhost servers publicly visible, even from
17353 behind restrictive firewalls or NAT without forwarded ports. The value for
17354 this service type is a @code{pagekite-configuration} record.
17356 Here's an example exposing the local HTTP and SSH daemons:
17359 (service pagekite-service-type
17360 (pagekite-configuration
17361 (kites '("http:@@kitename:localhost:80:@@kitesecret"
17362 "raw/22:@@kitename:localhost:22:@@kitesecret"))
17363 (extra-file "/etc/pagekite.rc")))
17367 @deftp {Data Type} pagekite-configuration
17368 Data type representing the configuration of PageKite.
17371 @item @code{package} (default: @var{pagekite})
17372 Package object of PageKite.
17374 @item @code{kitename} (default: @code{#f})
17375 PageKite name for authenticating to the frontend server.
17377 @item @code{kitesecret} (default: @code{#f})
17378 Shared secret for authenticating to the frontend server. You should probably
17379 put this inside @code{extra-file} instead.
17381 @item @code{frontend} (default: @code{#f})
17382 Connect to the named PageKite frontend server instead of the
17383 @uref{https://pagekite.net,,pagekite.net} service.
17385 @item @code{kites} (default: @code{'("http:@@kitename:localhost:80:@@kitesecret")})
17386 List of service kites to use. Exposes HTTP on port 80 by default. The format
17387 is @code{proto:kitename:host:port:secret}.
17389 @item @code{extra-file} (default: @code{#f})
17390 Extra configuration file to read, which you are expected to create manually.
17391 Use this to add additional options and manage shared secrets out-of-band.
17396 @defvr {Scheme Variable} yggdrasil-service-type
17397 The service type for connecting to the @uref{https://yggdrasil-network.github.io/,
17398 Yggdrasil network}, an early-stage implementation of a fully end-to-end
17399 encrypted IPv6 network.
17402 Yggdrasil provides name-independent routing with cryptographically generated
17403 addresses. Static addressing means you can keep the same address as long as
17404 you want, even if you move to a new location, or generate a new address (by
17405 generating new keys) whenever you want.
17406 @uref{https://yggdrasil-network.github.io/2018/07/28/addressing.html}
17409 Pass it a value of @code{yggdrasil-configuration} to connect it to public
17410 peers and/or local peers.
17412 Here is an example using public peers and a static address. The static
17413 signing and encryption keys are defined in @file{/etc/yggdrasil-private.conf}
17414 (the default value for @code{config-file}).
17417 ;; part of the operating-system declaration
17418 (service yggdrasil-service-type
17419 (yggdrasil-configuration
17420 (autoconf? #f) ;; use only the public peers
17423 ;; https://github.com/yggdrasil-network/public-peers
17424 '((peers . #("tcp://1.2.3.4:1337"))))
17425 ;; /etc/yggdrasil-private.conf is the default value for config-file
17429 # sample content for /etc/yggdrasil-private.conf
17431 # Your public encryption key. Your peers may ask you for this to put
17432 # into their AllowedEncryptionPublicKeys configuration.
17433 EncryptionPublicKey: 378dc5...
17435 # Your private encryption key. DO NOT share this with anyone!
17436 EncryptionPrivateKey: 0777...
17438 # Your public signing key. You should not ordinarily need to share
17439 # this with anyone.
17440 SigningPublicKey: e1664...
17442 # Your private signing key. DO NOT share this with anyone!
17443 SigningPrivateKey: 0589d...
17448 @deftp {Data Type} yggdrasil-configuration
17449 Data type representing the configuration of Yggdrasil.
17452 @item @code{package} (default: @code{yggdrasil})
17453 Package object of Yggdrasil.
17455 @item @code{json-config} (default: @code{'()})
17456 Contents of @file{/etc/yggdrasil.conf}. Will be merged with
17457 @file{/etc/yggdrasil-private.conf}. Note that these settings are stored in
17458 the Guix store, which is readable to all users. @strong{Do not store your
17459 private keys in it}. See the output of @code{yggdrasil -genconf} for a
17460 quick overview of valid keys and their default values.
17462 @item @code{autoconf?} (default: @code{#f})
17463 Whether to use automatic mode. Enabling it makes Yggdrasil use adynamic IP
17464 and peer with IPv6 neighbors.
17466 @item @code{log-level} (default: @code{'info})
17467 How much detail to include in logs. Use @code{'debug} for more detail.
17469 @item @code{log-to} (default: @code{'stdout})
17470 Where to send logs. By default, the service logs standard output to
17471 @file{/var/log/yggdrasil.log}. The alternative is @code{'syslog}, which
17472 sends output to the running syslog service.
17474 @item @code{config-file} (default: @code{"/etc/yggdrasil-private.conf"})
17475 What HJSON file to load sensitive data from. This is where private keys
17476 should be stored, which are necessary to specify if you don't want a
17477 randomized address after each restart. Use @code{#f} to disable. Options
17478 defined in this file take precedence over @code{json-config}. Use the output
17479 of @code{yggdrasil -genconf} as a starting point. To configure a static
17480 address, delete everything except these options:
17483 @item @code{EncryptionPublicKey}
17484 @item @code{EncryptionPrivateKey}
17485 @item @code{SigningPublicKey}
17486 @item @code{SigningPrivateKey}
17492 @deffn {Scheme Variable} keepalived-service-type
17493 This is the type for the @uref{https://www.keepalived.org/, Keepalived}
17494 routing software, @command{keepalived}. Its value must be an
17495 @code{keepalived-configuration} record as in this example for master
17499 (service keepalived-service-type
17500 (keepalived-configuration
17501 (config-file (local-file "keepalived-master.conf"))))
17504 where @file{keepalived-master.conf}:
17507 vrrp_instance my-group @{
17510 virtual_router_id 100
17512 unicast_peer @{ 10.0.0.2 @}
17513 virtual_ipaddress @{
17519 and for backup machine:
17522 (service keepalived-service-type
17523 (keepalived-configuration
17524 (config-file (local-file "keepalived-backup.conf"))))
17527 where @file{keepalived-backup.conf}:
17530 vrrp_instance my-group @{
17533 virtual_router_id 100
17535 unicast_peer @{ 10.0.0.3 @}
17536 virtual_ipaddress @{
17543 @node Unattended Upgrades
17544 @subsection Unattended Upgrades
17546 @cindex unattended upgrades
17547 @cindex upgrades, unattended
17548 Guix provides a service to perform @emph{unattended upgrades}:
17549 periodically, the system automatically reconfigures itself from the
17550 latest Guix. Guix System has several properties that make unattended
17555 upgrades are transactional (either the upgrade succeeds or it fails, but
17556 you cannot end up with an ``in-between'' system state);
17558 the upgrade log is kept---you can view it with @command{guix system
17559 list-generations}---and you can roll back to any previous generation,
17560 should the upgraded system fail to behave as intended;
17562 channel code is authenticated so you know you can only run genuine code
17563 (@pxref{Channels});
17565 @command{guix system reconfigure} prevents downgrades, which makes it
17566 immune to @dfn{downgrade attacks}.
17569 To set up unattended upgrades, add an instance of
17570 @code{unattended-upgrade-service-type} like the one below to the list of
17571 your operating system services:
17574 (service unattended-upgrade-service-type)
17577 The defaults above set up weekly upgrades: every Sunday at midnight.
17578 You do not need to provide the operating system configuration file: it
17579 uses @file{/run/current-system/configuration.scm}, which ensures it
17580 always uses your latest configuration---@pxref{provenance-service-type},
17581 for more information about this file.
17583 There are several things that can be configured, in particular the
17584 periodicity and services (daemons) to be restarted upon completion.
17585 When the upgrade is successful, the service takes care of deleting
17586 system generations older that some threshold, as per @command{guix
17587 system delete-generations}. See the reference below for details.
17589 To ensure that upgrades are actually happening, you can run
17590 @command{guix system describe}. To investigate upgrade failures, visit
17591 the unattended upgrade log file (see below).
17593 @defvr {Scheme Variable} unattended-upgrade-service-type
17594 This is the service type for unattended upgrades. It sets up an mcron
17595 job (@pxref{Scheduled Job Execution}) that runs @command{guix system
17596 reconfigure} from the latest version of the specified channels.
17598 Its value must be a @code{unattended-upgrade-configuration} record (see
17602 @deftp {Data Type} unattended-upgrade-configuration
17603 This data type represents the configuration of the unattended upgrade
17604 service. The following fields are available:
17607 @item @code{schedule} (default: @code{"30 01 * * 0"})
17608 This is the schedule of upgrades, expressed as a gexp containing an
17609 mcron job schedule (@pxref{Guile Syntax, mcron job specifications,,
17610 mcron, GNU@tie{}mcron}).
17612 @item @code{channels} (default: @code{#~%default-channels})
17613 This gexp specifies the channels to use for the upgrade
17614 (@pxref{Channels}). By default, the tip of the official @code{guix}
17617 @item @code{operating-system-file} (default: @code{"/run/current-system/configuration.scm"})
17618 This field specifies the operating system configuration file to use.
17619 The default is to reuse the config file of the current configuration.
17621 There are cases, though, where referring to
17622 @file{/run/current-system/configuration.scm} is not enough, for instance
17623 because that file refers to extra files (SSH public keys, extra
17624 configuration files, etc.) @i{via} @code{local-file} and similar
17625 constructs. For those cases, we recommend something along these lines:
17628 (unattended-upgrade-configuration
17629 (operating-system-file
17630 (file-append (local-file "." "config-dir" #:recursive? #t)
17634 The effect here is to import all of the current directory into the
17635 store, and to refer to @file{config.scm} within that directory.
17636 Therefore, uses of @code{local-file} within @file{config.scm} will work
17637 as expected. @xref{G-Expressions}, for information about
17638 @code{local-file} and @code{file-append}.
17640 @item @code{services-to-restart} (default: @code{'(mcron)})
17641 This field specifies the Shepherd services to restart when the upgrade
17644 Those services are restarted right away upon completion, as with
17645 @command{herd restart}, which ensures that the latest version is
17646 running---remember that by default @command{guix system reconfigure}
17647 only restarts services that are not currently running, which is
17648 conservative: it minimizes disruption but leaves outdated services
17651 Use @command{herd status} to find out candidates for restarting.
17652 @xref{Services}, for general information about services. Common
17653 services to restart would include @code{ntpd} and @code{ssh-daemon}.
17655 By default, the @code{mcron} service is restarted. This ensures that
17656 the latest version of the unattended upgrade job will be used next time.
17658 @item @code{system-expiration} (default: @code{(* 3 30 24 3600)})
17659 This is the expiration time in seconds for system generations. System
17660 generations older that this amount of time are deleted with
17661 @command{guix system delete-generations} when an upgrade completes.
17664 The unattended upgrade service does not run the garbage collector. You
17665 will probably want to set up your own mcron job to run @command{guix gc}
17669 @item @code{maximum-duration} (default: @code{3600})
17670 Maximum duration in seconds for the upgrade; past that time, the upgrade
17673 This is primarily useful to ensure the upgrade does not end up
17674 rebuilding or re-downloading ``the world''.
17676 @item @code{log-file} (default: @code{"/var/log/unattended-upgrade.log"})
17677 File where unattended upgrades are logged.
17682 @subsection X Window
17685 @cindex X Window System
17686 @cindex login manager
17687 Support for the X Window graphical display system---specifically
17688 Xorg---is provided by the @code{(gnu services xorg)} module. Note that
17689 there is no @code{xorg-service} procedure. Instead, the X server is
17690 started by the @dfn{login manager}, by default the GNOME Display Manager (GDM).
17693 @cindex GNOME, login manager
17694 GDM of course allows users to log in into window managers and desktop
17695 environments other than GNOME; for those using GNOME, GDM is required for
17696 features such as automatic screen locking.
17698 @cindex window manager
17699 To use X11, you must install at least one @dfn{window manager}---for
17700 example the @code{windowmaker} or @code{openbox} packages---preferably
17701 by adding it to the @code{packages} field of your operating system
17702 definition (@pxref{operating-system Reference, system-wide packages}).
17704 @defvr {Scheme Variable} gdm-service-type
17705 This is the type for the @uref{https://wiki.gnome.org/Projects/GDM/, GNOME
17706 Desktop Manager} (GDM), a program that manages graphical display servers and
17707 handles graphical user logins. Its value must be a @code{gdm-configuration}
17710 @cindex session types (X11)
17711 @cindex X11 session types
17712 GDM looks for @dfn{session types} described by the @file{.desktop} files in
17713 @file{/run/current-system/profile/share/xsessions} and allows users to choose
17714 a session from the log-in screen. Packages such as @code{gnome}, @code{xfce},
17715 and @code{i3} provide @file{.desktop} files; adding them to the system-wide
17716 set of packages automatically makes them available at the log-in screen.
17718 In addition, @file{~/.xsession} files are honored. When available,
17719 @file{~/.xsession} must be an executable that starts a window manager
17720 and/or other X clients.
17723 @deftp {Data Type} gdm-configuration
17725 @item @code{auto-login?} (default: @code{#f})
17726 @itemx @code{default-user} (default: @code{#f})
17727 When @code{auto-login?} is false, GDM presents a log-in screen.
17729 When @code{auto-login?} is true, GDM logs in directly as
17730 @code{default-user}.
17732 @item @code{debug?} (default: @code{#f})
17733 When true, GDM writes debug messages to its log.
17735 @item @code{gnome-shell-assets} (default: ...)
17736 List of GNOME Shell assets needed by GDM: icon theme, fonts, etc.
17738 @item @code{xorg-configuration} (default: @code{(xorg-configuration)})
17739 Configuration of the Xorg graphical server.
17741 @item @code{xsession} (default: @code{(xinitrc)})
17742 Script to run before starting a X session.
17744 @item @code{dbus-daemon} (default: @code{dbus-daemon-wrapper})
17745 File name of the @code{dbus-daemon} executable.
17747 @item @code{gdm} (default: @code{gdm})
17748 The GDM package to use.
17752 @defvr {Scheme Variable} slim-service-type
17753 This is the type for the SLiM graphical login manager for X11.
17755 Like GDM, SLiM looks for session types described by @file{.desktop} files and
17756 allows users to choose a session from the log-in screen using @kbd{F1}. It
17757 also honors @file{~/.xsession} files.
17759 Unlike GDM, SLiM does not spawn the user session on a different VT after
17760 logging in, which means that you can only start one graphical session. If you
17761 want to be able to run multiple graphical sessions at the same time you have
17762 to add multiple SLiM services to your system services. The following example
17763 shows how to replace the default GDM service with two SLiM services on tty7
17767 (use-modules (gnu services)
17768 (gnu services desktop)
17769 (gnu services xorg)
17770 (srfi srfi-1)) ;for 'remove'
17774 (services (cons* (service slim-service-type (slim-configuration
17777 (service slim-service-type (slim-configuration
17780 (remove (lambda (service)
17781 (eq? (service-kind service) gdm-service-type))
17782 %desktop-services))))
17787 @deftp {Data Type} slim-configuration
17788 Data type representing the configuration of @code{slim-service-type}.
17791 @item @code{allow-empty-passwords?} (default: @code{#t})
17792 Whether to allow logins with empty passwords.
17794 @item @code{auto-login?} (default: @code{#f})
17795 @itemx @code{default-user} (default: @code{""})
17796 When @code{auto-login?} is false, SLiM presents a log-in screen.
17798 When @code{auto-login?} is true, SLiM logs in directly as
17799 @code{default-user}.
17801 @item @code{theme} (default: @code{%default-slim-theme})
17802 @itemx @code{theme-name} (default: @code{%default-slim-theme-name})
17803 The graphical theme to use and its name.
17805 @item @code{auto-login-session} (default: @code{#f})
17806 If true, this must be the name of the executable to start as the default
17807 session---e.g., @code{(file-append windowmaker "/bin/windowmaker")}.
17809 If false, a session described by one of the available @file{.desktop}
17810 files in @code{/run/current-system/profile} and @code{~/.guix-profile}
17814 You must install at least one window manager in the system profile or in
17815 your user profile. Failing to do that, if @code{auto-login-session} is
17816 false, you will be unable to log in.
17819 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17820 Configuration of the Xorg graphical server.
17822 @item @code{display} (default @code{":0"})
17823 The display on which to start the Xorg graphical server.
17825 @item @code{vt} (default @code{"vt7"})
17826 The VT on which to start the Xorg graphical server.
17828 @item @code{xauth} (default: @code{xauth})
17829 The XAuth package to use.
17831 @item @code{shepherd} (default: @code{shepherd})
17832 The Shepherd package used when invoking @command{halt} and
17835 @item @code{sessreg} (default: @code{sessreg})
17836 The sessreg package used in order to register the session.
17838 @item @code{slim} (default: @code{slim})
17839 The SLiM package to use.
17843 @defvr {Scheme Variable} %default-theme
17844 @defvrx {Scheme Variable} %default-theme-name
17845 The default SLiM theme and its name.
17849 @deftp {Data Type} sddm-configuration
17850 This is the data type representing the SDDM service configuration.
17853 @item @code{display-server} (default: "x11")
17854 Select display server to use for the greeter. Valid values are
17855 @samp{"x11"} or @samp{"wayland"}.
17857 @item @code{numlock} (default: "on")
17858 Valid values are @samp{"on"}, @samp{"off"} or @samp{"none"}.
17860 @item @code{halt-command} (default @code{#~(string-apppend #$shepherd "/sbin/halt")})
17861 Command to run when halting.
17863 @item @code{reboot-command} (default @code{#~(string-append #$shepherd "/sbin/reboot")})
17864 Command to run when rebooting.
17866 @item @code{theme} (default "maldives")
17867 Theme to use. Default themes provided by SDDM are @samp{"elarun"},
17868 @samp{"maldives"} or @samp{"maya"}.
17870 @item @code{themes-directory} (default "/run/current-system/profile/share/sddm/themes")
17871 Directory to look for themes.
17873 @item @code{faces-directory} (default "/run/current-system/profile/share/sddm/faces")
17874 Directory to look for faces.
17876 @item @code{default-path} (default "/run/current-system/profile/bin")
17877 Default PATH to use.
17879 @item @code{minimum-uid} (default: 1000)
17880 Minimum UID displayed in SDDM and allowed for log-in.
17882 @item @code{maximum-uid} (default: 2000)
17883 Maximum UID to display in SDDM.
17885 @item @code{remember-last-user?} (default #t)
17886 Remember last user.
17888 @item @code{remember-last-session?} (default #t)
17889 Remember last session.
17891 @item @code{hide-users} (default "")
17892 Usernames to hide from SDDM greeter.
17894 @item @code{hide-shells} (default @code{#~(string-append #$shadow "/sbin/nologin")})
17895 Users with shells listed will be hidden from the SDDM greeter.
17897 @item @code{session-command} (default @code{#~(string-append #$sddm "/share/sddm/scripts/wayland-session")})
17898 Script to run before starting a wayland session.
17900 @item @code{sessions-directory} (default "/run/current-system/profile/share/wayland-sessions")
17901 Directory to look for desktop files starting wayland sessions.
17903 @item @code{xorg-configuration} (default @code{(xorg-configuration)})
17904 Configuration of the Xorg graphical server.
17906 @item @code{xauth-path} (default @code{#~(string-append #$xauth "/bin/xauth")})
17909 @item @code{xephyr-path} (default @code{#~(string-append #$xorg-server "/bin/Xephyr")})
17912 @item @code{xdisplay-start} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xsetup")})
17913 Script to run after starting xorg-server.
17915 @item @code{xdisplay-stop} (default @code{#~(string-append #$sddm "/share/sddm/scripts/Xstop")})
17916 Script to run before stopping xorg-server.
17918 @item @code{xsession-command} (default: @code{xinitrc})
17919 Script to run before starting a X session.
17921 @item @code{xsessions-directory} (default: "/run/current-system/profile/share/xsessions")
17922 Directory to look for desktop files starting X sessions.
17924 @item @code{minimum-vt} (default: 7)
17927 @item @code{auto-login-user} (default "")
17928 User to use for auto-login.
17930 @item @code{auto-login-session} (default "")
17931 Desktop file to use for auto-login.
17933 @item @code{relogin?} (default #f)
17934 Relogin after logout.
17939 @cindex login manager
17941 @defvr {Scheme Variable} sddm-service-type
17942 This is the type of the service to run the
17943 @uref{https://github.com/sddm/sddm,SDDM display manager}. Its value
17944 must be a @code{sddm-configuration} record (see below).
17946 Here's an example use:
17949 (service sddm-service-type
17950 (sddm-configuration
17951 (auto-login-user "alice")
17952 (auto-login-session "xfce.desktop")))
17956 @deftp {Data Type} sddm-configuration
17957 This data type represents the configuration of the SDDM login manager.
17958 The available fields are:
17961 @item @code{sddm} (default: @code{sddm})
17962 The SDDM package to use.
17964 @item @code{display-server} (default: @code{"x11"})
17965 This must be either @code{"x11"} or @code{"wayland"}.
17967 @c FIXME: Add more fields.
17969 @item @code{auto-login-user} (default: @code{""})
17970 If non-empty, this is the user account under which to log in
17973 @item @code{auto-login-session} (default: @code{""})
17974 If non-empty, this is the @file{.desktop} file name to use as the
17975 auto-login session.
17979 @cindex Xorg, configuration
17980 @deftp {Data Type} xorg-configuration
17981 This data type represents the configuration of the Xorg graphical display
17982 server. Note that there is no Xorg service; instead, the X server is started
17983 by a ``display manager'' such as GDM, SDDM, and SLiM@. Thus, the configuration
17984 of these display managers aggregates an @code{xorg-configuration} record.
17987 @item @code{modules} (default: @code{%default-xorg-modules})
17988 This is a list of @dfn{module packages} loaded by the Xorg
17989 server---e.g., @code{xf86-video-vesa}, @code{xf86-input-keyboard}, and so on.
17991 @item @code{fonts} (default: @code{%default-xorg-fonts})
17992 This is a list of font directories to add to the server's @dfn{font path}.
17994 @item @code{drivers} (default: @code{'()})
17995 This must be either the empty list, in which case Xorg chooses a graphics
17996 driver automatically, or a list of driver names that will be tried in this
17997 order---e.g., @code{("modesetting" "vesa")}.
17999 @item @code{resolutions} (default: @code{'()})
18000 When @code{resolutions} is the empty list, Xorg chooses an appropriate screen
18001 resolution. Otherwise, it must be a list of resolutions---e.g., @code{((1024
18004 @cindex keyboard layout, for Xorg
18005 @cindex keymap, for Xorg
18006 @item @code{keyboard-layout} (default: @code{#f})
18007 If this is @code{#f}, Xorg uses the default keyboard layout---usually US
18008 English (``qwerty'') for a 105-key PC keyboard.
18010 Otherwise this must be a @code{keyboard-layout} object specifying the keyboard
18011 layout in use when Xorg is running. @xref{Keyboard Layout}, for more
18012 information on how to specify the keyboard layout.
18014 @item @code{extra-config} (default: @code{'()})
18015 This is a list of strings or objects appended to the configuration file. It
18016 is used to pass extra text to be added verbatim to the configuration file.
18018 @item @code{server} (default: @code{xorg-server})
18019 This is the package providing the Xorg server.
18021 @item @code{server-arguments} (default: @code{%default-xorg-server-arguments})
18022 This is the list of command-line arguments to pass to the X server. The
18023 default is @code{-nolisten tcp}.
18027 @deffn {Scheme Procedure} set-xorg-configuration @var{config} @
18028 [@var{login-manager-service-type}]
18029 Tell the log-in manager (of type @var{login-manager-service-type}) to use
18030 @var{config}, an @code{<xorg-configuration>} record.
18032 Since the Xorg configuration is embedded in the log-in manager's
18033 configuration---e.g., @code{gdm-configuration}---this procedure provides a
18034 shorthand to set the Xorg configuration.
18037 @deffn {Scheme Procedure} xorg-start-command [@var{config}]
18038 Return a @code{startx} script in which the modules, fonts, etc. specified
18039 in @var{config}, are available. The result should be used in place of
18042 Usually the X server is started by a login manager.
18046 @deffn {Scheme Procedure} screen-locker-service @var{package} [@var{program}]
18047 Add @var{package}, a package for a screen locker or screen saver whose
18048 command is @var{program}, to the set of setuid programs and add a PAM entry
18049 for it. For example:
18052 (screen-locker-service xlockmore "xlock")
18055 makes the good ol' XlockMore usable.
18059 @node Printing Services
18060 @subsection Printing Services
18062 @cindex printer support with CUPS
18063 The @code{(gnu services cups)} module provides a Guix service definition
18064 for the CUPS printing service. To add printer support to a Guix
18065 system, add a @code{cups-service} to the operating system definition:
18067 @deffn {Scheme Variable} cups-service-type
18068 The service type for the CUPS print server. Its value should be a valid
18069 CUPS configuration (see below). To use the default settings, simply
18072 (service cups-service-type)
18076 The CUPS configuration controls the basic things about your CUPS
18077 installation: what interfaces it listens on, what to do if a print job
18078 fails, how much logging to do, and so on. To actually add a printer,
18079 you have to visit the @url{http://localhost:631} URL, or use a tool such
18080 as GNOME's printer configuration services. By default, configuring a
18081 CUPS service will generate a self-signed certificate if needed, for
18082 secure connections to the print server.
18084 Suppose you want to enable the Web interface of CUPS and also add
18085 support for Epson printers @i{via} the @code{epson-inkjet-printer-escpr}
18086 package and for HP printers @i{via} the @code{hplip-minimal} package.
18087 You can do that directly, like this (you need to use the
18088 @code{(gnu packages cups)} module):
18091 (service cups-service-type
18092 (cups-configuration
18093 (web-interface? #t)
18095 (list cups-filters epson-inkjet-printer-escpr hplip-minimal))))
18098 Note: If you wish to use the Qt5 based GUI which comes with the hplip
18099 package then it is suggested that you install the @code{hplip} package,
18100 either in your OS configuration file or as your user.
18102 The available configuration parameters follow. Each parameter
18103 definition is preceded by its type; for example, @samp{string-list foo}
18104 indicates that the @code{foo} parameter should be specified as a list of
18105 strings. There is also a way to specify the configuration as a string,
18106 if you have an old @code{cupsd.conf} file that you want to port over
18107 from some other system; see the end for more details.
18109 @c The following documentation was initially generated by
18110 @c (generate-documentation) in (gnu services cups). Manually maintained
18111 @c documentation is better, so we shouldn't hesitate to edit below as
18112 @c needed. However if the change you want to make to this documentation
18113 @c can be done in an automated way, it's probably easier to change
18114 @c (generate-documentation) than to make it below and have to deal with
18115 @c the churn as CUPS updates.
18118 Available @code{cups-configuration} fields are:
18120 @deftypevr {@code{cups-configuration} parameter} package cups
18124 @deftypevr {@code{cups-configuration} parameter} package-list extensions (default: @code{(list brlaser cups-filters epson-inkjet-printer-escpr foomatic-filters hplip-minimal splix)})
18125 Drivers and other extensions to the CUPS package.
18128 @deftypevr {@code{cups-configuration} parameter} files-configuration files-configuration
18129 Configuration of where to write logs, what directories to use for print
18130 spools, and related privileged configuration parameters.
18132 Available @code{files-configuration} fields are:
18134 @deftypevr {@code{files-configuration} parameter} log-location access-log
18135 Defines the access log filename. Specifying a blank filename disables
18136 access log generation. The value @code{stderr} causes log entries to be
18137 sent to the standard error file when the scheduler is running in the
18138 foreground, or to the system log daemon when run in the background. The
18139 value @code{syslog} causes log entries to be sent to the system log
18140 daemon. The server name may be included in filenames using the string
18141 @code{%s}, as in @code{/var/log/cups/%s-access_log}.
18143 Defaults to @samp{"/var/log/cups/access_log"}.
18146 @deftypevr {@code{files-configuration} parameter} file-name cache-dir
18147 Where CUPS should cache data.
18149 Defaults to @samp{"/var/cache/cups"}.
18152 @deftypevr {@code{files-configuration} parameter} string config-file-perm
18153 Specifies the permissions for all configuration files that the scheduler
18156 Note that the permissions for the printers.conf file are currently
18157 masked to only allow access from the scheduler user (typically root).
18158 This is done because printer device URIs sometimes contain sensitive
18159 authentication information that should not be generally known on the
18160 system. There is no way to disable this security feature.
18162 Defaults to @samp{"0640"}.
18165 @deftypevr {@code{files-configuration} parameter} log-location error-log
18166 Defines the error log filename. Specifying a blank filename disables
18167 error log generation. The value @code{stderr} causes log entries to be
18168 sent to the standard error file when the scheduler is running in the
18169 foreground, or to the system log daemon when run in the background. The
18170 value @code{syslog} causes log entries to be sent to the system log
18171 daemon. The server name may be included in filenames using the string
18172 @code{%s}, as in @code{/var/log/cups/%s-error_log}.
18174 Defaults to @samp{"/var/log/cups/error_log"}.
18177 @deftypevr {@code{files-configuration} parameter} string fatal-errors
18178 Specifies which errors are fatal, causing the scheduler to exit. The
18183 No errors are fatal.
18186 All of the errors below are fatal.
18189 Browsing initialization errors are fatal, for example failed connections
18190 to the DNS-SD daemon.
18193 Configuration file syntax errors are fatal.
18196 Listen or Port errors are fatal, except for IPv6 failures on the
18197 loopback or @code{any} addresses.
18200 Log file creation or write errors are fatal.
18203 Bad startup file permissions are fatal, for example shared TLS
18204 certificate and key files with world-read permissions.
18207 Defaults to @samp{"all -browse"}.
18210 @deftypevr {@code{files-configuration} parameter} boolean file-device?
18211 Specifies whether the file pseudo-device can be used for new printer
18212 queues. The URI @uref{file:///dev/null} is always allowed.
18214 Defaults to @samp{#f}.
18217 @deftypevr {@code{files-configuration} parameter} string group
18218 Specifies the group name or ID that will be used when executing external
18221 Defaults to @samp{"lp"}.
18224 @deftypevr {@code{files-configuration} parameter} string log-file-perm
18225 Specifies the permissions for all log files that the scheduler writes.
18227 Defaults to @samp{"0644"}.
18230 @deftypevr {@code{files-configuration} parameter} log-location page-log
18231 Defines the page log filename. Specifying a blank filename disables
18232 page log generation. The value @code{stderr} causes log entries to be
18233 sent to the standard error file when the scheduler is running in the
18234 foreground, or to the system log daemon when run in the background. The
18235 value @code{syslog} causes log entries to be sent to the system log
18236 daemon. The server name may be included in filenames using the string
18237 @code{%s}, as in @code{/var/log/cups/%s-page_log}.
18239 Defaults to @samp{"/var/log/cups/page_log"}.
18242 @deftypevr {@code{files-configuration} parameter} string remote-root
18243 Specifies the username that is associated with unauthenticated accesses
18244 by clients claiming to be the root user. The default is @code{remroot}.
18246 Defaults to @samp{"remroot"}.
18249 @deftypevr {@code{files-configuration} parameter} file-name request-root
18250 Specifies the directory that contains print jobs and other HTTP request
18253 Defaults to @samp{"/var/spool/cups"}.
18256 @deftypevr {@code{files-configuration} parameter} sandboxing sandboxing
18257 Specifies the level of security sandboxing that is applied to print
18258 filters, backends, and other child processes of the scheduler; either
18259 @code{relaxed} or @code{strict}. This directive is currently only
18260 used/supported on macOS.
18262 Defaults to @samp{strict}.
18265 @deftypevr {@code{files-configuration} parameter} file-name server-keychain
18266 Specifies the location of TLS certificates and private keys. CUPS will
18267 look for public and private keys in this directory: @file{.crt} files
18268 for PEM-encoded certificates and corresponding @file{.key} files for
18269 PEM-encoded private keys.
18271 Defaults to @samp{"/etc/cups/ssl"}.
18274 @deftypevr {@code{files-configuration} parameter} file-name server-root
18275 Specifies the directory containing the server configuration files.
18277 Defaults to @samp{"/etc/cups"}.
18280 @deftypevr {@code{files-configuration} parameter} boolean sync-on-close?
18281 Specifies whether the scheduler calls fsync(2) after writing
18282 configuration or state files.
18284 Defaults to @samp{#f}.
18287 @deftypevr {@code{files-configuration} parameter} space-separated-string-list system-group
18288 Specifies the group(s) to use for @code{@@SYSTEM} group authentication.
18291 @deftypevr {@code{files-configuration} parameter} file-name temp-dir
18292 Specifies the directory where temporary files are stored.
18294 Defaults to @samp{"/var/spool/cups/tmp"}.
18297 @deftypevr {@code{files-configuration} parameter} string user
18298 Specifies the user name or ID that is used when running external
18301 Defaults to @samp{"lp"}.
18304 @deftypevr {@code{files-configuration} parameter} string set-env
18305 Set the specified environment variable to be passed to child processes.
18307 Defaults to @samp{"variable value"}.
18311 @deftypevr {@code{cups-configuration} parameter} access-log-level access-log-level
18312 Specifies the logging level for the AccessLog file. The @code{config}
18313 level logs when printers and classes are added, deleted, or modified and
18314 when configuration files are accessed or updated. The @code{actions}
18315 level logs when print jobs are submitted, held, released, modified, or
18316 canceled, and any of the conditions for @code{config}. The @code{all}
18317 level logs all requests.
18319 Defaults to @samp{actions}.
18322 @deftypevr {@code{cups-configuration} parameter} boolean auto-purge-jobs?
18323 Specifies whether to purge job history data automatically when it is no
18324 longer required for quotas.
18326 Defaults to @samp{#f}.
18329 @deftypevr {@code{cups-configuration} parameter} comma-separated-string-list browse-dns-sd-sub-types
18330 Specifies a list of DNS-SD sub-types to advertise for each shared printer.
18331 For example, @samp{"_cups" "_print"} will tell network clients that both
18332 CUPS sharing and IPP Everywhere are supported.
18334 Defaults to @samp{"_cups"}.
18337 @deftypevr {@code{cups-configuration} parameter} browse-local-protocols browse-local-protocols
18338 Specifies which protocols to use for local printer sharing.
18340 Defaults to @samp{dnssd}.
18343 @deftypevr {@code{cups-configuration} parameter} boolean browse-web-if?
18344 Specifies whether the CUPS web interface is advertised.
18346 Defaults to @samp{#f}.
18349 @deftypevr {@code{cups-configuration} parameter} boolean browsing?
18350 Specifies whether shared printers are advertised.
18352 Defaults to @samp{#f}.
18355 @deftypevr {@code{cups-configuration} parameter} string classification
18356 Specifies the security classification of the server. Any valid banner
18357 name can be used, including @samp{"classified"}, @samp{"confidential"},
18358 @samp{"secret"}, @samp{"topsecret"}, and @samp{"unclassified"}, or the
18359 banner can be omitted to disable secure printing functions.
18361 Defaults to @samp{""}.
18364 @deftypevr {@code{cups-configuration} parameter} boolean classify-override?
18365 Specifies whether users may override the classification (cover page) of
18366 individual print jobs using the @code{job-sheets} option.
18368 Defaults to @samp{#f}.
18371 @deftypevr {@code{cups-configuration} parameter} default-auth-type default-auth-type
18372 Specifies the default type of authentication to use.
18374 Defaults to @samp{Basic}.
18377 @deftypevr {@code{cups-configuration} parameter} default-encryption default-encryption
18378 Specifies whether encryption will be used for authenticated requests.
18380 Defaults to @samp{Required}.
18383 @deftypevr {@code{cups-configuration} parameter} string default-language
18384 Specifies the default language to use for text and web content.
18386 Defaults to @samp{"en"}.
18389 @deftypevr {@code{cups-configuration} parameter} string default-paper-size
18390 Specifies the default paper size for new print queues. @samp{"Auto"}
18391 uses a locale-specific default, while @samp{"None"} specifies there is
18392 no default paper size. Specific size names are typically
18393 @samp{"Letter"} or @samp{"A4"}.
18395 Defaults to @samp{"Auto"}.
18398 @deftypevr {@code{cups-configuration} parameter} string default-policy
18399 Specifies the default access policy to use.
18401 Defaults to @samp{"default"}.
18404 @deftypevr {@code{cups-configuration} parameter} boolean default-shared?
18405 Specifies whether local printers are shared by default.
18407 Defaults to @samp{#t}.
18410 @deftypevr {@code{cups-configuration} parameter} non-negative-integer dirty-clean-interval
18411 Specifies the delay for updating of configuration and state files, in
18412 seconds. A value of 0 causes the update to happen as soon as possible,
18413 typically within a few milliseconds.
18415 Defaults to @samp{30}.
18418 @deftypevr {@code{cups-configuration} parameter} error-policy error-policy
18419 Specifies what to do when an error occurs. Possible values are
18420 @code{abort-job}, which will discard the failed print job;
18421 @code{retry-job}, which will retry the job at a later time;
18422 @code{retry-current-job}, which retries the failed job immediately; and
18423 @code{stop-printer}, which stops the printer.
18425 Defaults to @samp{stop-printer}.
18428 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-limit
18429 Specifies the maximum cost of filters that are run concurrently, which
18430 can be used to minimize disk, memory, and CPU resource problems. A
18431 limit of 0 disables filter limiting. An average print to a
18432 non-PostScript printer needs a filter limit of about 200. A PostScript
18433 printer needs about half that (100). Setting the limit below these
18434 thresholds will effectively limit the scheduler to printing a single job
18437 Defaults to @samp{0}.
18440 @deftypevr {@code{cups-configuration} parameter} non-negative-integer filter-nice
18441 Specifies the scheduling priority of filters that are run to print a
18442 job. The nice value ranges from 0, the highest priority, to 19, the
18445 Defaults to @samp{0}.
18448 @deftypevr {@code{cups-configuration} parameter} host-name-lookups host-name-lookups
18449 Specifies whether to do reverse lookups on connecting clients. The
18450 @code{double} setting causes @code{cupsd} to verify that the hostname
18451 resolved from the address matches one of the addresses returned for that
18452 hostname. Double lookups also prevent clients with unregistered
18453 addresses from connecting to your server. Only set this option to
18454 @code{#t} or @code{double} if absolutely required.
18456 Defaults to @samp{#f}.
18459 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-kill-delay
18460 Specifies the number of seconds to wait before killing the filters and
18461 backend associated with a canceled or held job.
18463 Defaults to @samp{30}.
18466 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-interval
18467 Specifies the interval between retries of jobs in seconds. This is
18468 typically used for fax queues but can also be used with normal print
18469 queues whose error policy is @code{retry-job} or
18470 @code{retry-current-job}.
18472 Defaults to @samp{30}.
18475 @deftypevr {@code{cups-configuration} parameter} non-negative-integer job-retry-limit
18476 Specifies the number of retries that are done for jobs. This is
18477 typically used for fax queues but can also be used with normal print
18478 queues whose error policy is @code{retry-job} or
18479 @code{retry-current-job}.
18481 Defaults to @samp{5}.
18484 @deftypevr {@code{cups-configuration} parameter} boolean keep-alive?
18485 Specifies whether to support HTTP keep-alive connections.
18487 Defaults to @samp{#t}.
18490 @deftypevr {@code{cups-configuration} parameter} non-negative-integer keep-alive-timeout
18491 Specifies how long an idle client connection remains open, in seconds.
18493 Defaults to @samp{30}.
18496 @deftypevr {@code{cups-configuration} parameter} non-negative-integer limit-request-body
18497 Specifies the maximum size of print files, IPP requests, and HTML form
18498 data. A limit of 0 disables the limit check.
18500 Defaults to @samp{0}.
18503 @deftypevr {@code{cups-configuration} parameter} multiline-string-list listen
18504 Listens on the specified interfaces for connections. Valid values are
18505 of the form @var{address}:@var{port}, where @var{address} is either an
18506 IPv6 address enclosed in brackets, an IPv4 address, or @code{*} to
18507 indicate all addresses. Values can also be file names of local UNIX
18508 domain sockets. The Listen directive is similar to the Port directive
18509 but allows you to restrict access to specific interfaces or networks.
18512 @deftypevr {@code{cups-configuration} parameter} non-negative-integer listen-back-log
18513 Specifies the number of pending connections that will be allowed. This
18514 normally only affects very busy servers that have reached the MaxClients
18515 limit, but can also be triggered by large numbers of simultaneous
18516 connections. When the limit is reached, the operating system will
18517 refuse additional connections until the scheduler can accept the pending
18520 Defaults to @samp{128}.
18523 @deftypevr {@code{cups-configuration} parameter} location-access-control-list location-access-controls
18524 Specifies a set of additional access controls.
18526 Available @code{location-access-controls} fields are:
18528 @deftypevr {@code{location-access-controls} parameter} file-name path
18529 Specifies the URI path to which the access control applies.
18532 @deftypevr {@code{location-access-controls} parameter} access-control-list access-controls
18533 Access controls for all access to this path, in the same format as the
18534 @code{access-controls} of @code{operation-access-control}.
18536 Defaults to @samp{()}.
18539 @deftypevr {@code{location-access-controls} parameter} method-access-control-list method-access-controls
18540 Access controls for method-specific access to this path.
18542 Defaults to @samp{()}.
18544 Available @code{method-access-controls} fields are:
18546 @deftypevr {@code{method-access-controls} parameter} boolean reverse?
18547 If @code{#t}, apply access controls to all methods except the listed
18548 methods. Otherwise apply to only the listed methods.
18550 Defaults to @samp{#f}.
18553 @deftypevr {@code{method-access-controls} parameter} method-list methods
18554 Methods to which this access control applies.
18556 Defaults to @samp{()}.
18559 @deftypevr {@code{method-access-controls} parameter} access-control-list access-controls
18560 Access control directives, as a list of strings. Each string should be
18561 one directive, such as @samp{"Order allow,deny"}.
18563 Defaults to @samp{()}.
18568 @deftypevr {@code{cups-configuration} parameter} non-negative-integer log-debug-history
18569 Specifies the number of debugging messages that are retained for logging
18570 if an error occurs in a print job. Debug messages are logged regardless
18571 of the LogLevel setting.
18573 Defaults to @samp{100}.
18576 @deftypevr {@code{cups-configuration} parameter} log-level log-level
18577 Specifies the level of logging for the ErrorLog file. The value
18578 @code{none} stops all logging while @code{debug2} logs everything.
18580 Defaults to @samp{info}.
18583 @deftypevr {@code{cups-configuration} parameter} log-time-format log-time-format
18584 Specifies the format of the date and time in the log files. The value
18585 @code{standard} logs whole seconds while @code{usecs} logs microseconds.
18587 Defaults to @samp{standard}.
18590 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients
18591 Specifies the maximum number of simultaneous clients that are allowed by
18594 Defaults to @samp{100}.
18597 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-clients-per-host
18598 Specifies the maximum number of simultaneous clients that are allowed
18599 from a single address.
18601 Defaults to @samp{100}.
18604 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-copies
18605 Specifies the maximum number of copies that a user can print of each
18608 Defaults to @samp{9999}.
18611 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-hold-time
18612 Specifies the maximum time a job may remain in the @code{indefinite}
18613 hold state before it is canceled. A value of 0 disables cancellation of
18616 Defaults to @samp{0}.
18619 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs
18620 Specifies the maximum number of simultaneous jobs that are allowed. Set
18621 to 0 to allow an unlimited number of jobs.
18623 Defaults to @samp{500}.
18626 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-printer
18627 Specifies the maximum number of simultaneous jobs that are allowed per
18628 printer. A value of 0 allows up to MaxJobs jobs per printer.
18630 Defaults to @samp{0}.
18633 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-jobs-per-user
18634 Specifies the maximum number of simultaneous jobs that are allowed per
18635 user. A value of 0 allows up to MaxJobs jobs per user.
18637 Defaults to @samp{0}.
18640 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-job-time
18641 Specifies the maximum time a job may take to print before it is
18642 canceled, in seconds. Set to 0 to disable cancellation of ``stuck'' jobs.
18644 Defaults to @samp{10800}.
18647 @deftypevr {@code{cups-configuration} parameter} non-negative-integer max-log-size
18648 Specifies the maximum size of the log files before they are rotated, in
18649 bytes. The value 0 disables log rotation.
18651 Defaults to @samp{1048576}.
18654 @deftypevr {@code{cups-configuration} parameter} non-negative-integer multiple-operation-timeout
18655 Specifies the maximum amount of time to allow between files in a
18656 multiple file print job, in seconds.
18658 Defaults to @samp{300}.
18661 @deftypevr {@code{cups-configuration} parameter} string page-log-format
18662 Specifies the format of PageLog lines. Sequences beginning with percent
18663 (@samp{%}) characters are replaced with the corresponding information,
18664 while all other characters are copied literally. The following percent
18665 sequences are recognized:
18669 insert a single percent character
18672 insert the value of the specified IPP attribute
18675 insert the number of copies for the current page
18678 insert the current page number
18681 insert the current date and time in common log format
18687 insert the printer name
18690 insert the username
18693 A value of the empty string disables page logging. The string @code{%p
18694 %u %j %T %P %C %@{job-billing@} %@{job-originating-host-name@}
18695 %@{job-name@} %@{media@} %@{sides@}} creates a page log with the
18698 Defaults to @samp{""}.
18701 @deftypevr {@code{cups-configuration} parameter} environment-variables environment-variables
18702 Passes the specified environment variable(s) to child processes; a list
18705 Defaults to @samp{()}.
18708 @deftypevr {@code{cups-configuration} parameter} policy-configuration-list policies
18709 Specifies named access control policies.
18711 Available @code{policy-configuration} fields are:
18713 @deftypevr {@code{policy-configuration} parameter} string name
18714 Name of the policy.
18717 @deftypevr {@code{policy-configuration} parameter} string job-private-access
18718 Specifies an access list for a job's private values. @code{@@ACL} maps
18719 to the printer's requesting-user-name-allowed or
18720 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18721 owner. @code{@@SYSTEM} maps to the groups listed for the
18722 @code{system-group} field of the @code{files-config} configuration,
18723 which is reified into the @code{cups-files.conf(5)} file. Other
18724 possible elements of the access list include specific user names, and
18725 @code{@@@var{group}} to indicate members of a specific group. The
18726 access list may also be simply @code{all} or @code{default}.
18728 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18731 @deftypevr {@code{policy-configuration} parameter} string job-private-values
18732 Specifies the list of job values to make private, or @code{all},
18733 @code{default}, or @code{none}.
18735 Defaults to @samp{"job-name job-originating-host-name
18736 job-originating-user-name phone"}.
18739 @deftypevr {@code{policy-configuration} parameter} string subscription-private-access
18740 Specifies an access list for a subscription's private values.
18741 @code{@@ACL} maps to the printer's requesting-user-name-allowed or
18742 requesting-user-name-denied values. @code{@@OWNER} maps to the job's
18743 owner. @code{@@SYSTEM} maps to the groups listed for the
18744 @code{system-group} field of the @code{files-config} configuration,
18745 which is reified into the @code{cups-files.conf(5)} file. Other
18746 possible elements of the access list include specific user names, and
18747 @code{@@@var{group}} to indicate members of a specific group. The
18748 access list may also be simply @code{all} or @code{default}.
18750 Defaults to @samp{"@@OWNER @@SYSTEM"}.
18753 @deftypevr {@code{policy-configuration} parameter} string subscription-private-values
18754 Specifies the list of job values to make private, or @code{all},
18755 @code{default}, or @code{none}.
18757 Defaults to @samp{"notify-events notify-pull-method notify-recipient-uri
18758 notify-subscriber-user-name notify-user-data"}.
18761 @deftypevr {@code{policy-configuration} parameter} operation-access-control-list access-controls
18762 Access control by IPP operation.
18764 Defaults to @samp{()}.
18768 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-files
18769 Specifies whether job files (documents) are preserved after a job is
18770 printed. If a numeric value is specified, job files are preserved for
18771 the indicated number of seconds after printing. Otherwise a boolean
18772 value applies indefinitely.
18774 Defaults to @samp{86400}.
18777 @deftypevr {@code{cups-configuration} parameter} boolean-or-non-negative-integer preserve-job-history
18778 Specifies whether the job history is preserved after a job is printed.
18779 If a numeric value is specified, the job history is preserved for the
18780 indicated number of seconds after printing. If @code{#t}, the job
18781 history is preserved until the MaxJobs limit is reached.
18783 Defaults to @samp{#t}.
18786 @deftypevr {@code{cups-configuration} parameter} non-negative-integer reload-timeout
18787 Specifies the amount of time to wait for job completion before
18788 restarting the scheduler.
18790 Defaults to @samp{30}.
18793 @deftypevr {@code{cups-configuration} parameter} string rip-cache
18794 Specifies the maximum amount of memory to use when converting documents
18795 into bitmaps for a printer.
18797 Defaults to @samp{"128m"}.
18800 @deftypevr {@code{cups-configuration} parameter} string server-admin
18801 Specifies the email address of the server administrator.
18803 Defaults to @samp{"root@@localhost.localdomain"}.
18806 @deftypevr {@code{cups-configuration} parameter} host-name-list-or-* server-alias
18807 The ServerAlias directive is used for HTTP Host header validation when
18808 clients connect to the scheduler from external interfaces. Using the
18809 special name @code{*} can expose your system to known browser-based DNS
18810 rebinding attacks, even when accessing sites through a firewall. If the
18811 auto-discovery of alternate names does not work, we recommend listing
18812 each alternate name with a ServerAlias directive instead of using
18815 Defaults to @samp{*}.
18818 @deftypevr {@code{cups-configuration} parameter} string server-name
18819 Specifies the fully-qualified host name of the server.
18821 Defaults to @samp{"localhost"}.
18824 @deftypevr {@code{cups-configuration} parameter} server-tokens server-tokens
18825 Specifies what information is included in the Server header of HTTP
18826 responses. @code{None} disables the Server header. @code{ProductOnly}
18827 reports @code{CUPS}. @code{Major} reports @code{CUPS 2}. @code{Minor}
18828 reports @code{CUPS 2.0}. @code{Minimal} reports @code{CUPS 2.0.0}.
18829 @code{OS} reports @code{CUPS 2.0.0 (@var{uname})} where @var{uname} is
18830 the output of the @code{uname} command. @code{Full} reports @code{CUPS
18831 2.0.0 (@var{uname}) IPP/2.0}.
18833 Defaults to @samp{Minimal}.
18836 @deftypevr {@code{cups-configuration} parameter} multiline-string-list ssl-listen
18837 Listens on the specified interfaces for encrypted connections. Valid
18838 values are of the form @var{address}:@var{port}, where @var{address} is
18839 either an IPv6 address enclosed in brackets, an IPv4 address, or
18840 @code{*} to indicate all addresses.
18842 Defaults to @samp{()}.
18845 @deftypevr {@code{cups-configuration} parameter} ssl-options ssl-options
18846 Sets encryption options. By default, CUPS only supports encryption
18847 using TLS v1.0 or higher using known secure cipher suites. Security is
18848 reduced when @code{Allow} options are used, and enhanced when @code{Deny}
18849 options are used. The @code{AllowRC4} option enables the 128-bit RC4 cipher
18850 suites, which are required for some older clients. The @code{AllowSSL3} option
18851 enables SSL v3.0, which is required for some older clients that do not support
18852 TLS v1.0. The @code{DenyCBC} option disables all CBC cipher suites. The
18853 @code{DenyTLS1.0} option disables TLS v1.0 support - this sets the minimum
18854 protocol version to TLS v1.1.
18856 Defaults to @samp{()}.
18859 @deftypevr {@code{cups-configuration} parameter} boolean strict-conformance?
18860 Specifies whether the scheduler requires clients to strictly adhere to
18861 the IPP specifications.
18863 Defaults to @samp{#f}.
18866 @deftypevr {@code{cups-configuration} parameter} non-negative-integer timeout
18867 Specifies the HTTP request timeout, in seconds.
18869 Defaults to @samp{300}.
18873 @deftypevr {@code{cups-configuration} parameter} boolean web-interface?
18874 Specifies whether the web interface is enabled.
18876 Defaults to @samp{#f}.
18879 At this point you're probably thinking ``oh dear, Guix manual, I like
18880 you but you can stop already with the configuration options''. Indeed.
18881 However, one more point: it could be that you have an existing
18882 @code{cupsd.conf} that you want to use. In that case, you can pass an
18883 @code{opaque-cups-configuration} as the configuration of a
18884 @code{cups-service-type}.
18886 Available @code{opaque-cups-configuration} fields are:
18888 @deftypevr {@code{opaque-cups-configuration} parameter} package cups
18892 @deftypevr {@code{opaque-cups-configuration} parameter} string cupsd.conf
18893 The contents of the @code{cupsd.conf}, as a string.
18896 @deftypevr {@code{opaque-cups-configuration} parameter} string cups-files.conf
18897 The contents of the @code{cups-files.conf} file, as a string.
18900 For example, if your @code{cupsd.conf} and @code{cups-files.conf} are in
18901 strings of the same name, you could instantiate a CUPS service like
18905 (service cups-service-type
18906 (opaque-cups-configuration
18907 (cupsd.conf cupsd.conf)
18908 (cups-files.conf cups-files.conf)))
18912 @node Desktop Services
18913 @subsection Desktop Services
18915 The @code{(gnu services desktop)} module provides services that are
18916 usually useful in the context of a ``desktop'' setup---that is, on a
18917 machine running a graphical display server, possibly with graphical user
18918 interfaces, etc. It also defines services that provide specific desktop
18919 environments like GNOME, Xfce or MATE.
18921 To simplify things, the module defines a variable containing the set of
18922 services that users typically expect on a machine with a graphical
18923 environment and networking:
18925 @defvr {Scheme Variable} %desktop-services
18926 This is a list of services that builds upon @code{%base-services} and
18927 adds or adjusts services for a typical ``desktop'' setup.
18929 In particular, it adds a graphical login manager (@pxref{X Window,
18930 @code{gdm-service-type}}), screen lockers, a network management tool
18931 (@pxref{Networking Services, @code{network-manager-service-type}}) with modem
18932 support (@pxref{Networking Services, @code{modem-manager-service-type}}),
18933 energy and color management services, the @code{elogind} login and seat
18934 manager, the Polkit privilege service, the GeoClue location service, the
18935 AccountsService daemon that allows authorized users change system passwords,
18936 an NTP client (@pxref{Networking Services}), the Avahi daemon, and has the
18937 name service switch service configured to be able to use @code{nss-mdns}
18938 (@pxref{Name Service Switch, mDNS}).
18941 The @code{%desktop-services} variable can be used as the @code{services}
18942 field of an @code{operating-system} declaration (@pxref{operating-system
18943 Reference, @code{services}}).
18945 Additionally, the @code{gnome-desktop-service-type},
18946 @code{xfce-desktop-service}, @code{mate-desktop-service-type},
18947 @code{lxqt-desktop-service-type} and @code{enlightenment-desktop-service-type}
18948 procedures can add GNOME, Xfce, MATE and/or Enlightenment to a system. To
18949 ``add GNOME'' means that system-level services like the backlight adjustment
18950 helpers and the power management utilities are added to the system, extending
18951 @code{polkit} and @code{dbus} appropriately, allowing GNOME to operate with
18952 elevated privileges on a limited number of special-purpose system interfaces.
18953 Additionally, adding a service made by @code{gnome-desktop-service-type} adds
18954 the GNOME metapackage to the system profile. Likewise, adding the Xfce
18955 service not only adds the @code{xfce} metapackage to the system profile, but
18956 it also gives the Thunar file manager the ability to open a ``root-mode'' file
18957 management window, if the user authenticates using the administrator's
18958 password via the standard polkit graphical interface. To ``add MATE'' means
18959 that @code{polkit} and @code{dbus} are extended appropriately, allowing MATE
18960 to operate with elevated privileges on a limited number of special-purpose
18961 system interfaces. Additionally, adding a service of type
18962 @code{mate-desktop-service-type} adds the MATE metapackage to the system
18963 profile. ``Adding Enlightenment'' means that @code{dbus} is extended
18964 appropriately, and several of Enlightenment's binaries are set as setuid,
18965 allowing Enlightenment's screen locker and other functionality to work as
18968 The desktop environments in Guix use the Xorg display server by
18969 default. If you'd like to use the newer display server protocol
18970 called Wayland, you need to use the @code{sddm-service} instead of
18971 GDM as the graphical login manager. You should then
18972 select the ``GNOME (Wayland)'' session in SDDM@. Alternatively you can
18973 also try starting GNOME on Wayland manually from a TTY with the
18974 command ``XDG_SESSION_TYPE=wayland exec dbus-run-session
18975 gnome-session``. Currently only GNOME has support for Wayland.
18977 @defvr {Scheme Variable} gnome-desktop-service-type
18978 This is the type of the service that adds the @uref{https://www.gnome.org,
18979 GNOME} desktop environment. Its value is a @code{gnome-desktop-configuration}
18980 object (see below).
18982 This service adds the @code{gnome} package to the system profile, and extends
18983 polkit with the actions from @code{gnome-settings-daemon}.
18986 @deftp {Data Type} gnome-desktop-configuration
18987 Configuration record for the GNOME desktop environment.
18990 @item @code{gnome} (default: @code{gnome})
18991 The GNOME package to use.
18995 @defvr {Scheme Variable} xfce-desktop-service-type
18996 This is the type of a service to run the @uref{Xfce, https://xfce.org/}
18997 desktop environment. Its value is an @code{xfce-desktop-configuration} object
19000 This service adds the @code{xfce} package to the system profile, and
19001 extends polkit with the ability for @code{thunar} to manipulate the file
19002 system as root from within a user session, after the user has authenticated
19003 with the administrator's password.
19005 Note that @code{xfce4-panel} and its plugin packages should be installed in
19006 the same profile to ensure compatibility. When using this service, you should
19007 add extra plugins (@code{xfce4-whiskermenu-plugin},
19008 @code{xfce4-weather-plugin}, etc.) to the @code{packages} field of your
19009 @code{operating-system}.
19012 @deftp {Data Type} xfce-desktop-configuration
19013 Configuration record for the Xfce desktop environment.
19016 @item @code{xfce} (default: @code{xfce})
19017 The Xfce package to use.
19021 @deffn {Scheme Variable} mate-desktop-service-type
19022 This is the type of the service that runs the @uref{https://mate-desktop.org/,
19023 MATE desktop environment}. Its value is a @code{mate-desktop-configuration}
19024 object (see below).
19026 This service adds the @code{mate} package to the system
19027 profile, and extends polkit with the actions from
19028 @code{mate-settings-daemon}.
19031 @deftp {Data Type} mate-desktop-configuration
19032 Configuration record for the MATE desktop environment.
19035 @item @code{mate} (default: @code{mate})
19036 The MATE package to use.
19040 @deffn {Scheme Variable} lxqt-desktop-service-type
19041 This is the type of the service that runs the @uref{https://lxqt.github.io,
19042 LXQt desktop environment}. Its value is a @code{lxqt-desktop-configuration}
19043 object (see below).
19045 This service adds the @code{lxqt} package to the system
19049 @deftp {Data Type} lxqt-desktop-configuration
19050 Configuration record for the LXQt desktop environment.
19053 @item @code{lxqt} (default: @code{lxqt})
19054 The LXQT package to use.
19058 @deffn {Scheme Variable} enlightenment-desktop-service-type
19059 Return a service that adds the @code{enlightenment} package to the system
19060 profile, and extends dbus with actions from @code{efl}.
19063 @deftp {Data Type} enlightenment-desktop-service-configuration
19065 @item @code{enlightenment} (default: @code{enlightenment})
19066 The enlightenment package to use.
19070 Because the GNOME, Xfce and MATE desktop services pull in so many packages,
19071 the default @code{%desktop-services} variable doesn't include any of
19072 them by default. To add GNOME, Xfce or MATE, just @code{cons} them onto
19073 @code{%desktop-services} in the @code{services} field of your
19074 @code{operating-system}:
19077 (use-modules (gnu))
19078 (use-service-modules desktop)
19081 ;; cons* adds items to the list given as its last argument.
19082 (services (cons* (service gnome-desktop-service-type)
19083 (service xfce-desktop-service)
19084 %desktop-services))
19088 These desktop environments will then be available as options in the
19089 graphical login window.
19091 The actual service definitions included in @code{%desktop-services} and
19092 provided by @code{(gnu services dbus)} and @code{(gnu services desktop)}
19093 are described below.
19095 @deffn {Scheme Procedure} dbus-service [#:dbus @var{dbus}] [#:services '()]
19096 Return a service that runs the ``system bus'', using @var{dbus}, with
19097 support for @var{services}.
19099 @uref{https://dbus.freedesktop.org/, D-Bus} is an inter-process communication
19100 facility. Its system bus is used to allow system services to communicate
19101 and to be notified of system-wide events.
19103 @var{services} must be a list of packages that provide an
19104 @file{etc/dbus-1/system.d} directory containing additional D-Bus configuration
19105 and policy files. For example, to allow avahi-daemon to use the system bus,
19106 @var{services} must be equal to @code{(list avahi)}.
19109 @deffn {Scheme Procedure} elogind-service [#:config @var{config}]
19110 Return a service that runs the @code{elogind} login and
19111 seat management daemon. @uref{https://github.com/elogind/elogind,
19112 Elogind} exposes a D-Bus interface that can be used to know which users
19113 are logged in, know what kind of sessions they have open, suspend the
19114 system, inhibit system suspend, reboot the system, and other tasks.
19116 Elogind handles most system-level power events for a computer, for
19117 example suspending the system when a lid is closed, or shutting it down
19118 when the power button is pressed.
19120 The @var{config} keyword argument specifies the configuration for
19121 elogind, and should be the result of an @code{(elogind-configuration
19122 (@var{parameter} @var{value})...)} invocation. Available parameters and
19123 their default values are:
19126 @item kill-user-processes?
19128 @item kill-only-users
19130 @item kill-exclude-users
19132 @item inhibit-delay-max-seconds
19134 @item handle-power-key
19136 @item handle-suspend-key
19138 @item handle-hibernate-key
19140 @item handle-lid-switch
19142 @item handle-lid-switch-docked
19144 @item handle-lid-switch-external-power
19146 @item power-key-ignore-inhibited?
19148 @item suspend-key-ignore-inhibited?
19150 @item hibernate-key-ignore-inhibited?
19152 @item lid-switch-ignore-inhibited?
19154 @item holdoff-timeout-seconds
19158 @item idle-action-seconds
19160 @item runtime-directory-size-percent
19162 @item runtime-directory-size
19166 @item suspend-state
19167 @code{("mem" "standby" "freeze")}
19170 @item hibernate-state
19172 @item hibernate-mode
19173 @code{("platform" "shutdown")}
19174 @item hybrid-sleep-state
19176 @item hybrid-sleep-mode
19177 @code{("suspend" "platform" "shutdown")}
19181 @deffn {Scheme Procedure} accountsservice-service @
19182 [#:accountsservice @var{accountsservice}]
19183 Return a service that runs AccountsService, a system service that can
19184 list available accounts, change their passwords, and so on.
19185 AccountsService integrates with PolicyKit to enable unprivileged users
19186 to acquire the capability to modify their system configuration.
19187 @uref{https://www.freedesktop.org/wiki/Software/AccountsService/, the
19188 accountsservice web site} for more information.
19190 The @var{accountsservice} keyword argument is the @code{accountsservice}
19191 package to expose as a service.
19194 @deffn {Scheme Procedure} polkit-service @
19195 [#:polkit @var{polkit}]
19196 Return a service that runs the
19197 @uref{https://www.freedesktop.org/wiki/Software/polkit/, Polkit privilege
19198 management service}, which allows system administrators to grant access to
19199 privileged operations in a structured way. By querying the Polkit service, a
19200 privileged system component can know when it should grant additional
19201 capabilities to ordinary users. For example, an ordinary user can be granted
19202 the capability to suspend the system if the user is logged in locally.
19205 @defvr {Scheme Variable} polkit-wheel-service
19206 Service that adds the @code{wheel} group as admins to the Polkit
19207 service. This makes it so that users in the @code{wheel} group are queried
19208 for their own passwords when performing administrative actions instead of
19209 @code{root}'s, similar to the behaviour used by @code{sudo}.
19212 @defvr {Scheme Variable} upower-service-type
19213 Service that runs @uref{https://upower.freedesktop.org/, @command{upowerd}}, a
19214 system-wide monitor for power consumption and battery levels, with the given
19215 configuration settings.
19217 It implements the @code{org.freedesktop.UPower} D-Bus interface, and is
19218 notably used by GNOME.
19221 @deftp {Data Type} upower-configuration
19222 Data type representation the configuration for UPower.
19226 @item @code{upower} (default: @var{upower})
19227 Package to use for @code{upower}.
19229 @item @code{watts-up-pro?} (default: @code{#f})
19230 Enable the Watts Up Pro device.
19232 @item @code{poll-batteries?} (default: @code{#t})
19233 Enable polling the kernel for battery level changes.
19235 @item @code{ignore-lid?} (default: @code{#f})
19236 Ignore the lid state, this can be useful if it's incorrect on a device.
19238 @item @code{use-percentage-for-policy?} (default: @code{#f})
19239 Whether battery percentage based policy should be used. The default is to use
19240 the time left, change to @code{#t} to use the percentage.
19242 @item @code{percentage-low} (default: @code{10})
19243 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19244 at which the battery is considered low.
19246 @item @code{percentage-critical} (default: @code{3})
19247 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19248 at which the battery is considered critical.
19250 @item @code{percentage-action} (default: @code{2})
19251 When @code{use-percentage-for-policy?} is @code{#t}, this sets the percentage
19252 at which action will be taken.
19254 @item @code{time-low} (default: @code{1200})
19255 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19256 seconds at which the battery is considered low.
19258 @item @code{time-critical} (default: @code{300})
19259 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19260 seconds at which the battery is considered critical.
19262 @item @code{time-action} (default: @code{120})
19263 When @code{use-time-for-policy?} is @code{#f}, this sets the time remaining in
19264 seconds at which action will be taken.
19266 @item @code{critical-power-action} (default: @code{'hybrid-sleep})
19267 The action taken when @code{percentage-action} or @code{time-action} is
19268 reached (depending on the configuration of @code{use-percentage-for-policy?}).
19270 Possible values are:
19280 @code{'hybrid-sleep}.
19286 @deffn {Scheme Procedure} udisks-service [#:udisks @var{udisks}]
19287 Return a service for @uref{https://udisks.freedesktop.org/docs/latest/,
19288 UDisks}, a @dfn{disk management} daemon that provides user interfaces
19289 with notifications and ways to mount/unmount disks. Programs that talk
19290 to UDisks include the @command{udisksctl} command, part of UDisks, and
19291 GNOME Disks. Note that Udisks relies on the @command{mount} command, so
19292 it will only be able to use the file-system utilities installed in the
19293 system profile. For example if you want to be able to mount NTFS
19294 file-systems in read and write fashion, you'll need to have
19295 @code{ntfs-3g} installed system-wide.
19298 @deffn {Scheme Variable} colord-service-type
19299 This is the type of the service that runs @command{colord}, a system
19300 service with a D-Bus
19301 interface to manage the color profiles of input and output devices such as
19302 screens and scanners. It is notably used by the GNOME Color Manager graphical
19303 tool. See @uref{https://www.freedesktop.org/software/colord/, the colord web
19304 site} for more information.
19307 @cindex scanner access
19308 @defvr {Scheme Variable} sane-service-type
19309 This service provides access to scanners @i{via}
19310 @uref{http://www.sane-project.org, SANE} by installing the necessary
19311 udev rules. It is included in @code{%desktop-services} (@pxref{Desktop
19312 Services}) and relies by default on @code{sane-backends-minimal} package
19313 (see below) for hardware support.
19316 @defvr {Scheme Variable} sane-backends-minimal
19317 The default package which the @code{sane-service-type} installs. It
19318 supports many recent scanners.
19321 @defvr {Scheme Variable} sane-backends
19322 This package includes support for all scanners that
19323 @code{sane-backends-minimal} supports, plus older Hewlett-Packard
19324 scanners supported by @code{hplip} package. In order to use this on
19325 a system which relies on @code{%desktop-services}, you may use
19326 @code{modify-services} (@pxref{Service Reference,
19327 @code{modify-services}}) as illustrated below:
19330 (use-modules (gnu))
19331 (use-service-modules
19334 (use-package-modules
19338 (define %my-desktop-services
19339 ;; List of desktop services that supports a broader range of scanners.
19340 (modify-services %desktop-services
19341 (sane-service-type _ => sane-backends)))
19345 (services %my-desktop-services)
19349 @deffn {Scheme Procedure} geoclue-application name [#:allowed? #t] [#:system? #f] [#:users '()]
19350 Return a configuration allowing an application to access GeoClue
19351 location data. @var{name} is the Desktop ID of the application, without
19352 the @code{.desktop} part. If @var{allowed?} is true, the application
19353 will have access to location information by default. The boolean
19354 @var{system?} value indicates whether an application is a system component
19355 or not. Finally @var{users} is a list of UIDs of all users for which
19356 this application is allowed location info access. An empty users list
19357 means that all users are allowed.
19360 @defvr {Scheme Variable} %standard-geoclue-applications
19361 The standard list of well-known GeoClue application configurations,
19362 granting authority to the GNOME date-and-time utility to ask for the
19363 current location in order to set the time zone, and allowing the
19364 IceCat and Epiphany web browsers to request location information.
19365 IceCat and Epiphany both query the user before allowing a web page to
19366 know the user's location.
19369 @deffn {Scheme Procedure} geoclue-service [#:colord @var{colord}] @
19370 [#:whitelist '()] @
19371 [#:wifi-geolocation-url "https://location.services.mozilla.com/v1/geolocate?key=geoclue"] @
19372 [#:submit-data? #f]
19373 [#:wifi-submission-url "https://location.services.mozilla.com/v1/submit?key=geoclue"] @
19374 [#:submission-nick "geoclue"] @
19375 [#:applications %standard-geoclue-applications]
19376 Return a service that runs the GeoClue location service. This service
19377 provides a D-Bus interface to allow applications to request access to a
19378 user's physical location, and optionally to add information to online
19379 location databases. See
19380 @uref{https://wiki.freedesktop.org/www/Software/GeoClue/, the GeoClue
19381 web site} for more information.
19384 @deffn {Scheme Procedure} bluetooth-service [#:bluez @var{bluez}] @
19385 [@w{#:auto-enable? #f}]
19386 Return a service that runs the @command{bluetoothd} daemon, which
19387 manages all the Bluetooth devices and provides a number of D-Bus
19388 interfaces. When AUTO-ENABLE? is true, the bluetooth controller is
19389 powered automatically at boot, which can be useful when using a
19390 bluetooth keyboard or mouse.
19392 Users need to be in the @code{lp} group to access the D-Bus service.
19395 @defvr {Scheme Variable} gnome-keyring-service-type
19396 This is the type of the service that adds the
19397 @uref{https://wiki.gnome.org/Projects/GnomeKeyring, GNOME Keyring}. Its
19398 value is a @code{gnome-keyring-configuration} object (see below).
19400 This service adds the @code{gnome-keyring} package to the system profile
19401 and extends PAM with entries using @code{pam_gnome_keyring.so}, unlocking
19402 a user's login keyring when they log in or setting its password with passwd.
19405 @deftp {Data Type} gnome-keyring-configuration
19406 Configuration record for the GNOME Keyring service.
19409 @item @code{keyring} (default: @code{gnome-keyring})
19410 The GNOME keyring package to use.
19412 @item @code{pam-services}
19413 A list of @code{(@var{service} . @var{kind})} pairs denoting PAM
19414 services to extend, where @var{service} is the name of an existing
19415 service to extend and @var{kind} is one of @code{login} or
19418 If @code{login} is given, it adds an optional
19419 @code{pam_gnome_keyring.so} to the auth block without arguments and to
19420 the session block with @code{auto_start}. If @code{passwd} is given, it
19421 adds an optional @code{pam_gnome_keyring.so} to the password block
19424 By default, this field contains ``gdm-password'' with the value @code{login}
19425 and ``passwd'' is with the value @code{passwd}.
19430 @node Sound Services
19431 @subsection Sound Services
19433 @cindex sound support
19435 @cindex PulseAudio, sound support
19437 The @code{(gnu services sound)} module provides a service to configure the
19438 Advanced Linux Sound Architecture (ALSA) system, which makes PulseAudio the
19439 preferred ALSA output driver.
19441 @deffn {Scheme Variable} alsa-service-type
19442 This is the type for the @uref{https://alsa-project.org/, Advanced Linux Sound
19443 Architecture} (ALSA) system, which generates the @file{/etc/asound.conf}
19444 configuration file. The value for this type is a @command{alsa-configuration}
19445 record as in this example:
19448 (service alsa-service-type)
19451 See below for details about @code{alsa-configuration}.
19454 @deftp {Data Type} alsa-configuration
19455 Data type representing the configuration for @code{alsa-service}.
19458 @item @code{alsa-plugins} (default: @var{alsa-plugins})
19459 @code{alsa-plugins} package to use.
19461 @item @code{pulseaudio?} (default: @var{#t})
19462 Whether ALSA applications should transparently be made to use the
19463 @uref{https://www.pulseaudio.org/, PulseAudio} sound server.
19465 Using PulseAudio allows you to run several sound-producing applications
19466 at the same time and to individual control them @i{via}
19467 @command{pavucontrol}, among other things.
19469 @item @code{extra-options} (default: @var{""})
19470 String to append to the @file{/etc/asound.conf} file.
19475 Individual users who want to override the system configuration of ALSA can do
19476 it with the @file{~/.asoundrc} file:
19479 # In guix, we have to specify the absolute path for plugins.
19481 lib "/home/alice/.guix-profile/lib/alsa-lib/libasound_module_pcm_jack.so"
19484 # Routing ALSA to jack:
19485 # <http://jackaudio.org/faq/routing_alsa.html>.
19489 0 system:playback_1
19490 1 system:playback_2
19507 See @uref{https://www.alsa-project.org/main/index.php/Asoundrc} for the
19510 @deffn {Scheme Variable} pulseaudio-service-type
19511 This is the type for the @uref{https://www.pulseaudio.org/, PulseAudio}
19512 sound server. It exists to allow system overrides of the default settings
19513 via @code{pulseaudio-configuration}, see below.
19516 This service overrides per-user configuration files. If you want
19517 PulseAudio to honor configuration files in @file{~/.config/pulse} you
19518 have to unset the environment variables @env{PULSE_CONFIG} and
19519 @env{PULSE_CLIENTCONFIG} in your @file{~/.bash_profile}.
19523 This service on its own does not ensure, that the @code{pulseaudio} package
19524 exists on your machine. It merely adds configuration files for it, as
19525 detailed below. In the (admittedly unlikely) case, that you find yourself
19526 without a @code{pulseaudio} package, consider enabling it through the
19527 @code{alsa-service-type} above.
19531 @deftp {Data Type} pulseaudio-configuration
19532 Data type representing the configuration for @code{pulseaudio-service}.
19535 @item @code{client-conf} (default: @code{'()})
19536 List of settings to set in @file{client.conf}.
19537 Accepts a list of strings or a symbol-value pairs. A string will be
19538 inserted as-is with a newline added. A pair will be formatted as
19539 ``key = value'', again with a newline added.
19541 @item @code{daemon-conf} (default: @code{'((flat-volumes . no))})
19542 List of settings to set in @file{daemon.conf}, formatted just like
19545 @item @code{script-file} (default: @code{(file-append pulseaudio "/etc/pulse/default.pa")})
19546 Script file to use as @file{default.pa}.
19548 @item @code{system-script-file} (default: @code{(file-append pulseaudio "/etc/pulse/system.pa")})
19549 Script file to use as @file{system.pa}.
19553 @deffn {Scheme Variable} ladspa-service-type
19554 This service sets the @var{LADSPA_PATH} variable, so that programs, which
19555 respect it, e.g. PulseAudio, can load LADSPA plugins.
19557 The following example will setup the service to enable modules from the
19558 @code{swh-plugins} package:
19561 (service ladspa-service-type
19562 (ladspa-configuration (plugins (list swh-plugins))))
19565 See @uref{http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html} for the
19570 @node Database Services
19571 @subsection Database Services
19575 The @code{(gnu services databases)} module provides the following services.
19577 @subsubheading PostgreSQL
19579 The following example describes a PostgreSQL service with the default
19583 (service postgresql-service-type
19584 (postgresql-configuration
19585 (postgresql postgresql-10)))
19588 If the services fails to start, it may be due to an incompatible
19589 cluster already present in @var{data-directory}. Adjust it (or, if you
19590 don't need the cluster anymore, delete @var{data-directory}), then
19591 restart the service.
19593 Peer authentication is used by default and the @code{postgres} user
19594 account has no shell, which prevents the direct execution of @code{psql}
19595 commands as this user. To use @code{psql}, you can temporarily log in
19596 as @code{postgres} using a shell, create a PostgreSQL superuser with the
19597 same name as one of the system users and then create the associated
19601 sudo -u postgres -s /bin/sh
19602 createuser --interactive
19603 createdb $MY_USER_LOGIN # Replace appropriately.
19606 @deftp {Data Type} postgresql-configuration
19607 Data type representing the configuration for the
19608 @code{postgresql-service-type}.
19611 @item @code{postgresql}
19612 PostgreSQL package to use for the service.
19614 @item @code{port} (default: @code{5432})
19615 Port on which PostgreSQL should listen.
19617 @item @code{locale} (default: @code{"en_US.utf8"})
19618 Locale to use as the default when creating the database cluster.
19620 @item @code{config-file} (default: @code{(postgresql-config-file)})
19621 The configuration file to use when running PostgreSQL@. The default
19622 behaviour uses the postgresql-config-file record with the default values
19625 @item @code{log-directory} (default: @code{"/var/log/postgresql"})
19626 The directory where @command{pg_ctl} output will be written in a file
19627 named @code{"pg_ctl.log"}. This file can be useful to debug PostgreSQL
19628 configuration errors for instance.
19630 @item @code{data-directory} (default: @code{"/var/lib/postgresql/data"})
19631 Directory in which to store the data.
19633 @item @code{extension-packages} (default: @code{'()})
19634 @cindex postgresql extension-packages
19635 Additional extensions are loaded from packages listed in
19636 @var{extension-packages}. Extensions are available at runtime. For instance,
19637 to create a geographic database using the @code{postgis} extension, a user can
19638 configure the postgresql-service as in this example:
19642 (use-package-modules databases geo)
19646 ;; postgresql is required to run `psql' but postgis is not required for
19647 ;; proper operation.
19648 (packages (cons* postgresql %base-packages))
19651 (service postgresql-service-type
19652 (postgresql-configuration
19653 (postgresql postgresql-10)
19654 (extension-packages (list postgis))))
19658 Then the extension becomes visible and you can initialise an empty geographic
19659 database in this way:
19663 > create database postgistest;
19664 > \connect postgistest;
19665 > create extension postgis;
19666 > create extension postgis_topology;
19669 There is no need to add this field for contrib extensions such as hstore or
19670 dblink as they are already loadable by postgresql. This field is only
19671 required to add extensions provided by other packages.
19676 @deftp {Data Type} postgresql-config-file
19677 Data type representing the PostgreSQL configuration file. As shown in
19678 the following example, this can be used to customize the configuration
19679 of PostgreSQL@. Note that you can use any G-expression or filename in
19680 place of this record, if you already have a configuration file you'd
19681 like to use for example.
19684 (service postgresql-service-type
19685 (postgresql-configuration
19687 (postgresql-config-file
19688 (log-destination "stderr")
19690 (plain-file "pg_hba.conf"
19692 local all all trust
19693 host all all 127.0.0.1/32 md5
19694 host all all ::1/128 md5"))
19696 '(("session_preload_libraries" "auto_explain")
19697 ("random_page_cost" 2)
19698 ("auto_explain.log_min_duration" "100 ms")
19699 ("work_mem" "500 MB")
19700 ("logging_collector" #t)
19701 ("log_directory" "/var/log/postgresql")))))))
19705 @item @code{log-destination} (default: @code{"syslog"})
19706 The logging method to use for PostgreSQL@. Multiple values are accepted,
19707 separated by commas.
19709 @item @code{hba-file} (default: @code{%default-postgres-hba})
19710 Filename or G-expression for the host-based authentication
19713 @item @code{ident-file} (default: @code{%default-postgres-ident})
19714 Filename or G-expression for the user name mapping configuration.
19716 @item @code{socket-directory} (default: @code{"/var/run/postgresql"})
19717 Specifies the directory of the Unix-domain socket(s) on which PostgreSQL
19718 is to listen for connections from client applications. If set to
19719 @code{#false} PostgreSQL does not listen on any Unix-domain sockets, in
19720 which case only TCP/IP sockets can be used to connect to the server.
19722 @item @code{extra-config} (default: @code{'()})
19723 List of additional keys and values to include in the PostgreSQL config
19724 file. Each entry in the list should be a list where the first element
19725 is the key, and the remaining elements are the values.
19727 The values can be numbers, booleans or strings and will be mapped to
19728 PostgreSQL parameters types @code{Boolean}, @code{String},
19729 @code{Numeric}, @code{Numeric with Unit} and @code{Enumerated} described
19730 @uref{https://www.postgresql.org/docs/current/config-setting.html,
19736 @deffn {Scheme Variable} postgresql-role-service-type
19737 This service allows to create PostgreSQL roles and databases after
19738 PostgreSQL service start. Here is an example of its use.
19741 (service postgresql-role-service-type
19742 (postgresql-role-configuration
19744 (list (postgresql-role
19746 (create-database? #t))))))
19749 This service can be extended with extra roles, as in this
19753 (service-extension postgresql-role-service-type
19754 (const (postgresql-role
19756 (create-database? #t))))
19760 @deftp {Data Type} postgresql-role
19761 PostgreSQL manages database access permissions using the concept of
19762 roles. A role can be thought of as either a database user, or a group
19763 of database users, depending on how the role is set up. Roles can own
19764 database objects (for example, tables) and can assign privileges on
19765 those objects to other roles to control who has access to which objects.
19771 @item @code{permissions} (default: @code{'(createdb login)})
19772 The role permissions list. Supported permissions are @code{bypassrls},
19773 @code{createdb}, @code{createrole}, @code{login}, @code{replication} and
19776 @item @code{create-database?} (default: @code{#f})
19777 Whether to create a database with the same name as the role.
19782 @deftp {Data Type} postgresql-role-configuration
19783 Data type representing the configuration of
19784 @var{postgresql-role-service-type}.
19787 @item @code{host} (default: @code{"/var/run/postgresql"})
19788 The PostgreSQL host to connect to.
19790 @item @code{log} (default: @code{"/var/log/postgresql_roles.log"})
19791 File name of the log file.
19793 @item @code{roles} (default: @code{'()})
19794 The initial PostgreSQL roles to create.
19798 @subsubheading MariaDB/MySQL
19800 @defvr {Scheme Variable} mysql-service-type
19801 This is the service type for a MySQL or MariaDB database server. Its value
19802 is a @code{mysql-configuration} object that specifies which package to use,
19803 as well as various settings for the @command{mysqld} daemon.
19806 @deftp {Data Type} mysql-configuration
19807 Data type representing the configuration of @var{mysql-service-type}.
19810 @item @code{mysql} (default: @var{mariadb})
19811 Package object of the MySQL database server, can be either @var{mariadb}
19814 For MySQL, a temporary root password will be displayed at activation time.
19815 For MariaDB, the root password is empty.
19817 @item @code{bind-address} (default: @code{"127.0.0.1"})
19818 The IP on which to listen for network connections. Use @code{"0.0.0.0"}
19819 to bind to all available network interfaces.
19821 @item @code{port} (default: @code{3306})
19822 TCP port on which the database server listens for incoming connections.
19824 @item @code{socket} (default: @code{"/run/mysqld/mysqld.sock"})
19825 Socket file to use for local (non-network) connections.
19827 @item @code{extra-content} (default: @code{""})
19828 Additional settings for the @file{my.cnf} configuration file.
19830 @item @code{auto-upgrade?} (default: @code{#t})
19831 Whether to automatically run @command{mysql_upgrade} after starting the
19832 service. This is necessary to upgrade the @dfn{system schema} after
19833 ``major'' updates (such as switching from MariaDB 10.4 to 10.5), but can
19834 be disabled if you would rather do that manually.
19839 @subsubheading Memcached
19841 @defvr {Scheme Variable} memcached-service-type
19842 This is the service type for the @uref{https://memcached.org/,
19843 Memcached} service, which provides a distributed in memory cache. The
19844 value for the service type is a @code{memcached-configuration} object.
19848 (service memcached-service-type)
19851 @deftp {Data Type} memcached-configuration
19852 Data type representing the configuration of memcached.
19855 @item @code{memcached} (default: @code{memcached})
19856 The Memcached package to use.
19858 @item @code{interfaces} (default: @code{'("0.0.0.0")})
19859 Network interfaces on which to listen.
19861 @item @code{tcp-port} (default: @code{11211})
19862 Port on which to accept connections.
19864 @item @code{udp-port} (default: @code{11211})
19865 Port on which to accept UDP connections on, a value of 0 will disable
19866 listening on a UDP socket.
19868 @item @code{additional-options} (default: @code{'()})
19869 Additional command line options to pass to @code{memcached}.
19873 @subsubheading Redis
19875 @defvr {Scheme Variable} redis-service-type
19876 This is the service type for the @uref{https://redis.io/, Redis}
19877 key/value store, whose value is a @code{redis-configuration} object.
19880 @deftp {Data Type} redis-configuration
19881 Data type representing the configuration of redis.
19884 @item @code{redis} (default: @code{redis})
19885 The Redis package to use.
19887 @item @code{bind} (default: @code{"127.0.0.1"})
19888 Network interface on which to listen.
19890 @item @code{port} (default: @code{6379})
19891 Port on which to accept connections on, a value of 0 will disable
19892 listening on a TCP socket.
19894 @item @code{working-directory} (default: @code{"/var/lib/redis"})
19895 Directory in which to store the database and related files.
19899 @node Mail Services
19900 @subsection Mail Services
19904 The @code{(gnu services mail)} module provides Guix service definitions
19905 for email services: IMAP, POP3, and LMTP servers, as well as mail
19906 transport agents (MTAs). Lots of acronyms! These services are detailed
19907 in the subsections below.
19909 @subsubheading Dovecot Service
19911 @deffn {Scheme Procedure} dovecot-service [#:config (dovecot-configuration)]
19912 Return a service that runs the Dovecot IMAP/POP3/LMTP mail server.
19915 By default, Dovecot does not need much configuration; the default
19916 configuration object created by @code{(dovecot-configuration)} will
19917 suffice if your mail is delivered to @code{~/Maildir}. A self-signed
19918 certificate will be generated for TLS-protected connections, though
19919 Dovecot will also listen on cleartext ports by default. There are a
19920 number of options, though, which mail administrators might need to change,
19921 and as is the case with other services, Guix allows the system
19922 administrator to specify these parameters via a uniform Scheme interface.
19924 For example, to specify that mail is located at @code{maildir~/.mail},
19925 one would instantiate the Dovecot service like this:
19928 (dovecot-service #:config
19929 (dovecot-configuration
19930 (mail-location "maildir:~/.mail")))
19933 The available configuration parameters follow. Each parameter
19934 definition is preceded by its type; for example, @samp{string-list foo}
19935 indicates that the @code{foo} parameter should be specified as a list of
19936 strings. There is also a way to specify the configuration as a string,
19937 if you have an old @code{dovecot.conf} file that you want to port over
19938 from some other system; see the end for more details.
19940 @c The following documentation was initially generated by
19941 @c (generate-documentation) in (gnu services mail). Manually maintained
19942 @c documentation is better, so we shouldn't hesitate to edit below as
19943 @c needed. However if the change you want to make to this documentation
19944 @c can be done in an automated way, it's probably easier to change
19945 @c (generate-documentation) than to make it below and have to deal with
19946 @c the churn as dovecot updates.
19948 Available @code{dovecot-configuration} fields are:
19950 @deftypevr {@code{dovecot-configuration} parameter} package dovecot
19951 The dovecot package.
19954 @deftypevr {@code{dovecot-configuration} parameter} comma-separated-string-list listen
19955 A list of IPs or hosts where to listen for connections. @samp{*}
19956 listens on all IPv4 interfaces, @samp{::} listens on all IPv6
19957 interfaces. If you want to specify non-default ports or anything more
19958 complex, customize the address and port fields of the
19959 @samp{inet-listener} of the specific services you are interested in.
19962 @deftypevr {@code{dovecot-configuration} parameter} protocol-configuration-list protocols
19963 List of protocols we want to serve. Available protocols include
19964 @samp{imap}, @samp{pop3}, and @samp{lmtp}.
19966 Available @code{protocol-configuration} fields are:
19968 @deftypevr {@code{protocol-configuration} parameter} string name
19969 The name of the protocol.
19972 @deftypevr {@code{protocol-configuration} parameter} string auth-socket-path
19973 UNIX socket path to the master authentication server to find users.
19974 This is used by imap (for shared users) and lda.
19975 It defaults to @samp{"/var/run/dovecot/auth-userdb"}.
19978 @deftypevr {@code{protocol-configuration} parameter} space-separated-string-list mail-plugins
19979 Space separated list of plugins to load.
19982 @deftypevr {@code{protocol-configuration} parameter} non-negative-integer mail-max-userip-connections
19983 Maximum number of IMAP connections allowed for a user from each IP
19984 address. NOTE: The username is compared case-sensitively.
19985 Defaults to @samp{10}.
19990 @deftypevr {@code{dovecot-configuration} parameter} service-configuration-list services
19991 List of services to enable. Available services include @samp{imap},
19992 @samp{imap-login}, @samp{pop3}, @samp{pop3-login}, @samp{auth}, and
19995 Available @code{service-configuration} fields are:
19997 @deftypevr {@code{service-configuration} parameter} string kind
19998 The service kind. Valid values include @code{director},
19999 @code{imap-login}, @code{pop3-login}, @code{lmtp}, @code{imap},
20000 @code{pop3}, @code{auth}, @code{auth-worker}, @code{dict},
20001 @code{tcpwrap}, @code{quota-warning}, or anything else.
20004 @deftypevr {@code{service-configuration} parameter} listener-configuration-list listeners
20005 Listeners for the service. A listener is either a
20006 @code{unix-listener-configuration}, a @code{fifo-listener-configuration}, or
20007 an @code{inet-listener-configuration}.
20008 Defaults to @samp{()}.
20010 Available @code{unix-listener-configuration} fields are:
20012 @deftypevr {@code{unix-listener-configuration} parameter} string path
20013 Path to the file, relative to @code{base-dir} field. This is also used as
20017 @deftypevr {@code{unix-listener-configuration} parameter} string mode
20018 The access mode for the socket.
20019 Defaults to @samp{"0600"}.
20022 @deftypevr {@code{unix-listener-configuration} parameter} string user
20023 The user to own the socket.
20024 Defaults to @samp{""}.
20027 @deftypevr {@code{unix-listener-configuration} parameter} string group
20028 The group to own the socket.
20029 Defaults to @samp{""}.
20033 Available @code{fifo-listener-configuration} fields are:
20035 @deftypevr {@code{fifo-listener-configuration} parameter} string path
20036 Path to the file, relative to @code{base-dir} field. This is also used as
20040 @deftypevr {@code{fifo-listener-configuration} parameter} string mode
20041 The access mode for the socket.
20042 Defaults to @samp{"0600"}.
20045 @deftypevr {@code{fifo-listener-configuration} parameter} string user
20046 The user to own the socket.
20047 Defaults to @samp{""}.
20050 @deftypevr {@code{fifo-listener-configuration} parameter} string group
20051 The group to own the socket.
20052 Defaults to @samp{""}.
20056 Available @code{inet-listener-configuration} fields are:
20058 @deftypevr {@code{inet-listener-configuration} parameter} string protocol
20059 The protocol to listen for.
20062 @deftypevr {@code{inet-listener-configuration} parameter} string address
20063 The address on which to listen, or empty for all addresses.
20064 Defaults to @samp{""}.
20067 @deftypevr {@code{inet-listener-configuration} parameter} non-negative-integer port
20068 The port on which to listen.
20071 @deftypevr {@code{inet-listener-configuration} parameter} boolean ssl?
20072 Whether to use SSL for this service; @samp{yes}, @samp{no}, or
20074 Defaults to @samp{#t}.
20079 @deftypevr {@code{service-configuration} parameter} non-negative-integer client-limit
20080 Maximum number of simultaneous client connections per process. Once
20081 this number of connections is received, the next incoming connection
20082 will prompt Dovecot to spawn another process. If set to 0,
20083 @code{default-client-limit} is used instead.
20085 Defaults to @samp{0}.
20089 @deftypevr {@code{service-configuration} parameter} non-negative-integer service-count
20090 Number of connections to handle before starting a new process.
20091 Typically the only useful values are 0 (unlimited) or 1. 1 is more
20092 secure, but 0 is faster. <doc/wiki/LoginProcess.txt>.
20093 Defaults to @samp{1}.
20097 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-limit
20098 Maximum number of processes that can exist for this service. If set to
20099 0, @code{default-process-limit} is used instead.
20101 Defaults to @samp{0}.
20105 @deftypevr {@code{service-configuration} parameter} non-negative-integer process-min-avail
20106 Number of processes to always keep waiting for more connections.
20107 Defaults to @samp{0}.
20110 @deftypevr {@code{service-configuration} parameter} non-negative-integer vsz-limit
20111 If you set @samp{service-count 0}, you probably need to grow
20113 Defaults to @samp{256000000}.
20118 @deftypevr {@code{dovecot-configuration} parameter} dict-configuration dict
20119 Dict configuration, as created by the @code{dict-configuration}
20122 Available @code{dict-configuration} fields are:
20124 @deftypevr {@code{dict-configuration} parameter} free-form-fields entries
20125 A list of key-value pairs that this dict should hold.
20126 Defaults to @samp{()}.
20131 @deftypevr {@code{dovecot-configuration} parameter} passdb-configuration-list passdbs
20132 A list of passdb configurations, each one created by the
20133 @code{passdb-configuration} constructor.
20135 Available @code{passdb-configuration} fields are:
20137 @deftypevr {@code{passdb-configuration} parameter} string driver
20138 The driver that the passdb should use. Valid values include
20139 @samp{pam}, @samp{passwd}, @samp{shadow}, @samp{bsdauth}, and
20141 Defaults to @samp{"pam"}.
20144 @deftypevr {@code{passdb-configuration} parameter} space-separated-string-list args
20145 Space separated list of arguments to the passdb driver.
20146 Defaults to @samp{""}.
20151 @deftypevr {@code{dovecot-configuration} parameter} userdb-configuration-list userdbs
20152 List of userdb configurations, each one created by the
20153 @code{userdb-configuration} constructor.
20155 Available @code{userdb-configuration} fields are:
20157 @deftypevr {@code{userdb-configuration} parameter} string driver
20158 The driver that the userdb should use. Valid values include
20159 @samp{passwd} and @samp{static}.
20160 Defaults to @samp{"passwd"}.
20163 @deftypevr {@code{userdb-configuration} parameter} space-separated-string-list args
20164 Space separated list of arguments to the userdb driver.
20165 Defaults to @samp{""}.
20168 @deftypevr {@code{userdb-configuration} parameter} free-form-args override-fields
20169 Override fields from passwd.
20170 Defaults to @samp{()}.
20175 @deftypevr {@code{dovecot-configuration} parameter} plugin-configuration plugin-configuration
20176 Plug-in configuration, created by the @code{plugin-configuration}
20180 @deftypevr {@code{dovecot-configuration} parameter} list-of-namespace-configuration namespaces
20181 List of namespaces. Each item in the list is created by the
20182 @code{namespace-configuration} constructor.
20184 Available @code{namespace-configuration} fields are:
20186 @deftypevr {@code{namespace-configuration} parameter} string name
20187 Name for this namespace.
20190 @deftypevr {@code{namespace-configuration} parameter} string type
20191 Namespace type: @samp{private}, @samp{shared} or @samp{public}.
20192 Defaults to @samp{"private"}.
20195 @deftypevr {@code{namespace-configuration} parameter} string separator
20196 Hierarchy separator to use. You should use the same separator for
20197 all namespaces or some clients get confused. @samp{/} is usually a good
20198 one. The default however depends on the underlying mail storage
20200 Defaults to @samp{""}.
20203 @deftypevr {@code{namespace-configuration} parameter} string prefix
20204 Prefix required to access this namespace. This needs to be
20205 different for all namespaces. For example @samp{Public/}.
20206 Defaults to @samp{""}.
20209 @deftypevr {@code{namespace-configuration} parameter} string location
20210 Physical location of the mailbox. This is in the same format as
20211 mail_location, which is also the default for it.
20212 Defaults to @samp{""}.
20215 @deftypevr {@code{namespace-configuration} parameter} boolean inbox?
20216 There can be only one INBOX, and this setting defines which
20218 Defaults to @samp{#f}.
20221 @deftypevr {@code{namespace-configuration} parameter} boolean hidden?
20222 If namespace is hidden, it's not advertised to clients via NAMESPACE
20223 extension. You'll most likely also want to set @samp{list? #f}. This is mostly
20224 useful when converting from another server with different namespaces
20225 which you want to deprecate but still keep working. For example you can
20226 create hidden namespaces with prefixes @samp{~/mail/}, @samp{~%u/mail/}
20228 Defaults to @samp{#f}.
20231 @deftypevr {@code{namespace-configuration} parameter} boolean list?
20232 Show the mailboxes under this namespace with the LIST command. This
20233 makes the namespace visible for clients that do not support the NAMESPACE
20234 extension. The special @code{children} value lists child mailboxes, but
20235 hides the namespace prefix.
20236 Defaults to @samp{#t}.
20239 @deftypevr {@code{namespace-configuration} parameter} boolean subscriptions?
20240 Namespace handles its own subscriptions. If set to @code{#f}, the
20241 parent namespace handles them. The empty prefix should always have this
20243 Defaults to @samp{#t}.
20246 @deftypevr {@code{namespace-configuration} parameter} mailbox-configuration-list mailboxes
20247 List of predefined mailboxes in this namespace.
20248 Defaults to @samp{()}.
20250 Available @code{mailbox-configuration} fields are:
20252 @deftypevr {@code{mailbox-configuration} parameter} string name
20253 Name for this mailbox.
20256 @deftypevr {@code{mailbox-configuration} parameter} string auto
20257 @samp{create} will automatically create this mailbox.
20258 @samp{subscribe} will both create and subscribe to the mailbox.
20259 Defaults to @samp{"no"}.
20262 @deftypevr {@code{mailbox-configuration} parameter} space-separated-string-list special-use
20263 List of IMAP @code{SPECIAL-USE} attributes as specified by RFC 6154.
20264 Valid values are @code{\All}, @code{\Archive}, @code{\Drafts},
20265 @code{\Flagged}, @code{\Junk}, @code{\Sent}, and @code{\Trash}.
20266 Defaults to @samp{()}.
20273 @deftypevr {@code{dovecot-configuration} parameter} file-name base-dir
20274 Base directory where to store runtime data.
20275 Defaults to @samp{"/var/run/dovecot/"}.
20278 @deftypevr {@code{dovecot-configuration} parameter} string login-greeting
20279 Greeting message for clients.
20280 Defaults to @samp{"Dovecot ready."}.
20283 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-trusted-networks
20284 List of trusted network ranges. Connections from these IPs are
20285 allowed to override their IP addresses and ports (for logging and for
20286 authentication checks). @samp{disable-plaintext-auth} is also ignored
20287 for these networks. Typically you would specify your IMAP proxy servers
20289 Defaults to @samp{()}.
20292 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-access-sockets
20293 List of login access check sockets (e.g.@: tcpwrap).
20294 Defaults to @samp{()}.
20297 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-proctitle?
20298 Show more verbose process titles (in ps). Currently shows user name
20299 and IP address. Useful for seeing who is actually using the IMAP
20300 processes (e.g.@: shared mailboxes or if the same uid is used for multiple
20302 Defaults to @samp{#f}.
20305 @deftypevr {@code{dovecot-configuration} parameter} boolean shutdown-clients?
20306 Should all processes be killed when Dovecot master process shuts down.
20307 Setting this to @code{#f} means that Dovecot can be upgraded without
20308 forcing existing client connections to close (although that could also
20309 be a problem if the upgrade is e.g.@: due to a security fix).
20310 Defaults to @samp{#t}.
20313 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer doveadm-worker-count
20314 If non-zero, run mail commands via this many connections to doveadm
20315 server, instead of running them directly in the same process.
20316 Defaults to @samp{0}.
20319 @deftypevr {@code{dovecot-configuration} parameter} string doveadm-socket-path
20320 UNIX socket or host:port used for connecting to doveadm server.
20321 Defaults to @samp{"doveadm-server"}.
20324 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list import-environment
20325 List of environment variables that are preserved on Dovecot startup
20326 and passed down to all of its child processes. You can also give
20327 key=value pairs to always set specific settings.
20330 @deftypevr {@code{dovecot-configuration} parameter} boolean disable-plaintext-auth?
20331 Disable LOGIN command and all other plaintext authentications unless
20332 SSL/TLS is used (LOGINDISABLED capability). Note that if the remote IP
20333 matches the local IP (i.e.@: you're connecting from the same computer),
20334 the connection is considered secure and plaintext authentication is
20335 allowed. See also ssl=required setting.
20336 Defaults to @samp{#t}.
20339 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-cache-size
20340 Authentication cache size (e.g.@: @samp{#e10e6}). 0 means it's disabled.
20341 Note that bsdauth, PAM and vpopmail require @samp{cache-key} to be set
20342 for caching to be used.
20343 Defaults to @samp{0}.
20346 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-ttl
20347 Time to live for cached data. After TTL expires the cached record
20348 is no longer used, *except* if the main database lookup returns internal
20349 failure. We also try to handle password changes automatically: If
20350 user's previous authentication was successful, but this one wasn't, the
20351 cache isn't used. For now this works only with plaintext
20353 Defaults to @samp{"1 hour"}.
20356 @deftypevr {@code{dovecot-configuration} parameter} string auth-cache-negative-ttl
20357 TTL for negative hits (user not found, password mismatch).
20358 0 disables caching them completely.
20359 Defaults to @samp{"1 hour"}.
20362 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-realms
20363 List of realms for SASL authentication mechanisms that need them.
20364 You can leave it empty if you don't want to support multiple realms.
20365 Many clients simply use the first one listed here, so keep the default
20367 Defaults to @samp{()}.
20370 @deftypevr {@code{dovecot-configuration} parameter} string auth-default-realm
20371 Default realm/domain to use if none was specified. This is used for
20372 both SASL realms and appending @@domain to username in plaintext
20374 Defaults to @samp{""}.
20377 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-chars
20378 List of allowed characters in username. If the user-given username
20379 contains a character not listed in here, the login automatically fails.
20380 This is just an extra check to make sure user can't exploit any
20381 potential quote escaping vulnerabilities with SQL/LDAP databases. If
20382 you want to allow all characters, set this value to empty.
20383 Defaults to @samp{"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@@"}.
20386 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-translation
20387 Username character translations before it's looked up from
20388 databases. The value contains series of from -> to characters. For
20389 example @samp{#@@/@@} means that @samp{#} and @samp{/} characters are
20390 translated to @samp{@@}.
20391 Defaults to @samp{""}.
20394 @deftypevr {@code{dovecot-configuration} parameter} string auth-username-format
20395 Username formatting before it's looked up from databases. You can
20396 use the standard variables here, e.g.@: %Lu would lowercase the username,
20397 %n would drop away the domain if it was given, or @samp{%n-AT-%d} would
20398 change the @samp{@@} into @samp{-AT-}. This translation is done after
20399 @samp{auth-username-translation} changes.
20400 Defaults to @samp{"%Lu"}.
20403 @deftypevr {@code{dovecot-configuration} parameter} string auth-master-user-separator
20404 If you want to allow master users to log in by specifying the master
20405 username within the normal username string (i.e.@: not using SASL
20406 mechanism's support for it), you can specify the separator character
20407 here. The format is then <username><separator><master username>.
20408 UW-IMAP uses @samp{*} as the separator, so that could be a good
20410 Defaults to @samp{""}.
20413 @deftypevr {@code{dovecot-configuration} parameter} string auth-anonymous-username
20414 Username to use for users logging in with ANONYMOUS SASL
20416 Defaults to @samp{"anonymous"}.
20419 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer auth-worker-max-count
20420 Maximum number of dovecot-auth worker processes. They're used to
20421 execute blocking passdb and userdb queries (e.g.@: MySQL and PAM).
20422 They're automatically created and destroyed as needed.
20423 Defaults to @samp{30}.
20426 @deftypevr {@code{dovecot-configuration} parameter} string auth-gssapi-hostname
20427 Host name to use in GSSAPI principal names. The default is to use
20428 the name returned by gethostname(). Use @samp{$ALL} (with quotes) to
20429 allow all keytab entries.
20430 Defaults to @samp{""}.
20433 @deftypevr {@code{dovecot-configuration} parameter} string auth-krb5-keytab
20434 Kerberos keytab to use for the GSSAPI mechanism. Will use the
20435 system default (usually @file{/etc/krb5.keytab}) if not specified. You may
20436 need to change the auth service to run as root to be able to read this
20438 Defaults to @samp{""}.
20441 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-use-winbind?
20442 Do NTLM and GSS-SPNEGO authentication using Samba's winbind daemon
20443 and @samp{ntlm-auth} helper.
20444 <doc/wiki/Authentication/Mechanisms/Winbind.txt>.
20445 Defaults to @samp{#f}.
20448 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-winbind-helper-path
20449 Path for Samba's @samp{ntlm-auth} helper binary.
20450 Defaults to @samp{"/usr/bin/ntlm_auth"}.
20453 @deftypevr {@code{dovecot-configuration} parameter} string auth-failure-delay
20454 Time to delay before replying to failed authentications.
20455 Defaults to @samp{"2 secs"}.
20458 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-require-client-cert?
20459 Require a valid SSL client certificate or the authentication
20461 Defaults to @samp{#f}.
20464 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-ssl-username-from-cert?
20465 Take the username from client's SSL certificate, using
20466 @code{X509_NAME_get_text_by_NID()} which returns the subject's DN's
20468 Defaults to @samp{#f}.
20471 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list auth-mechanisms
20472 List of wanted authentication mechanisms. Supported mechanisms are:
20473 @samp{plain}, @samp{login}, @samp{digest-md5}, @samp{cram-md5},
20474 @samp{ntlm}, @samp{rpa}, @samp{apop}, @samp{anonymous}, @samp{gssapi},
20475 @samp{otp}, @samp{skey}, and @samp{gss-spnego}. NOTE: See also
20476 @samp{disable-plaintext-auth} setting.
20479 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-servers
20480 List of IPs or hostnames to all director servers, including ourself.
20481 Ports can be specified as ip:port. The default port is the same as what
20482 director service's @samp{inet-listener} is using.
20483 Defaults to @samp{()}.
20486 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list director-mail-servers
20487 List of IPs or hostnames to all backend mail servers. Ranges are
20488 allowed too, like 10.0.0.10-10.0.0.30.
20489 Defaults to @samp{()}.
20492 @deftypevr {@code{dovecot-configuration} parameter} string director-user-expire
20493 How long to redirect users to a specific server after it no longer
20494 has any connections.
20495 Defaults to @samp{"15 min"}.
20498 @deftypevr {@code{dovecot-configuration} parameter} string director-username-hash
20499 How the username is translated before being hashed. Useful values
20500 include %Ln if user can log in with or without @@domain, %Ld if mailboxes
20501 are shared within domain.
20502 Defaults to @samp{"%Lu"}.
20505 @deftypevr {@code{dovecot-configuration} parameter} string log-path
20506 Log file to use for error messages. @samp{syslog} logs to syslog,
20507 @samp{/dev/stderr} logs to stderr.
20508 Defaults to @samp{"syslog"}.
20511 @deftypevr {@code{dovecot-configuration} parameter} string info-log-path
20512 Log file to use for informational messages. Defaults to
20514 Defaults to @samp{""}.
20517 @deftypevr {@code{dovecot-configuration} parameter} string debug-log-path
20518 Log file to use for debug messages. Defaults to
20519 @samp{info-log-path}.
20520 Defaults to @samp{""}.
20523 @deftypevr {@code{dovecot-configuration} parameter} string syslog-facility
20524 Syslog facility to use if you're logging to syslog. Usually if you
20525 don't want to use @samp{mail}, you'll use local0..local7. Also other
20526 standard facilities are supported.
20527 Defaults to @samp{"mail"}.
20530 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-verbose?
20531 Log unsuccessful authentication attempts and the reasons why they
20533 Defaults to @samp{#f}.
20536 @deftypevr {@code{dovecot-configuration} parameter} string auth-verbose-passwords
20537 In case of password mismatches, log the attempted password. Valid
20538 values are no, plain and sha1. sha1 can be useful for detecting brute
20539 force password attempts vs. user simply trying the same password over
20540 and over again. You can also truncate the value to n chars by appending
20541 ":n" (e.g.@: sha1:6).
20542 Defaults to @samp{"no"}.
20545 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug?
20546 Even more verbose logging for debugging purposes. Shows for example
20548 Defaults to @samp{#f}.
20551 @deftypevr {@code{dovecot-configuration} parameter} boolean auth-debug-passwords?
20552 In case of password mismatches, log the passwords and used scheme so
20553 the problem can be debugged. Enabling this also enables
20555 Defaults to @samp{#f}.
20558 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-debug?
20559 Enable mail process debugging. This can help you figure out why
20560 Dovecot isn't finding your mails.
20561 Defaults to @samp{#f}.
20564 @deftypevr {@code{dovecot-configuration} parameter} boolean verbose-ssl?
20565 Show protocol level SSL errors.
20566 Defaults to @samp{#f}.
20569 @deftypevr {@code{dovecot-configuration} parameter} string log-timestamp
20570 Prefix for each line written to log file. % codes are in
20571 strftime(3) format.
20572 Defaults to @samp{"\"%b %d %H:%M:%S \""}.
20575 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list login-log-format-elements
20576 List of elements we want to log. The elements which have a
20577 non-empty variable value are joined together to form a comma-separated
20581 @deftypevr {@code{dovecot-configuration} parameter} string login-log-format
20582 Login log format. %s contains @samp{login-log-format-elements}
20583 string, %$ contains the data we want to log.
20584 Defaults to @samp{"%$: %s"}.
20587 @deftypevr {@code{dovecot-configuration} parameter} string mail-log-prefix
20588 Log prefix for mail processes. See doc/wiki/Variables.txt for list
20589 of possible variables you can use.
20590 Defaults to @samp{"\"%s(%u)<%@{pid@}><%@{session@}>: \""}.
20593 @deftypevr {@code{dovecot-configuration} parameter} string deliver-log-format
20594 Format to use for logging mail deliveries. You can use variables:
20597 Delivery status message (e.g.@: @samp{saved to INBOX})
20609 Defaults to @samp{"msgid=%m: %$"}.
20612 @deftypevr {@code{dovecot-configuration} parameter} string mail-location
20613 Location for users' mailboxes. The default is empty, which means
20614 that Dovecot tries to find the mailboxes automatically. This won't work
20615 if the user doesn't yet have any mail, so you should explicitly tell
20616 Dovecot the full location.
20618 If you're using mbox, giving a path to the INBOX
20619 file (e.g.@: @file{/var/mail/%u}) isn't enough. You'll also need to tell Dovecot
20620 where the other mailboxes are kept. This is called the @emph{root mail
20621 directory}, and it must be the first path given in the
20622 @samp{mail-location} setting.
20624 There are a few special variables you can use, e.g.:
20630 user part in user@@domain, same as %u if there's no domain
20632 domain part in user@@domain, empty if there's no domain
20637 See doc/wiki/Variables.txt for full list. Some examples:
20639 @item maildir:~/Maildir
20640 @item mbox:~/mail:INBOX=/var/mail/%u
20641 @item mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%
20643 Defaults to @samp{""}.
20646 @deftypevr {@code{dovecot-configuration} parameter} string mail-uid
20647 System user and group used to access mails. If you use multiple,
20648 userdb can override these by returning uid or gid fields. You can use
20649 either numbers or names. <doc/wiki/UserIds.txt>.
20650 Defaults to @samp{""}.
20653 @deftypevr {@code{dovecot-configuration} parameter} string mail-gid
20655 Defaults to @samp{""}.
20658 @deftypevr {@code{dovecot-configuration} parameter} string mail-privileged-group
20659 Group to enable temporarily for privileged operations. Currently
20660 this is used only with INBOX when either its initial creation or
20661 dotlocking fails. Typically this is set to @samp{"mail"} to give access to
20663 Defaults to @samp{""}.
20666 @deftypevr {@code{dovecot-configuration} parameter} string mail-access-groups
20667 Grant access to these supplementary groups for mail processes.
20668 Typically these are used to set up access to shared mailboxes. Note
20669 that it may be dangerous to set these if users can create symlinks
20670 (e.g.@: if @samp{mail} group is set here, @code{ln -s /var/mail ~/mail/var}
20671 could allow a user to delete others' mailboxes, or @code{ln -s
20672 /secret/shared/box ~/mail/mybox} would allow reading it). Defaults to
20676 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-full-filesystem-access?
20677 Allow full file system access to clients. There's no access checks
20678 other than what the operating system does for the active UID/GID@. It
20679 works with both maildir and mboxes, allowing you to prefix mailboxes
20680 names with e.g.@: @file{/path/} or @file{~user/}.
20681 Defaults to @samp{#f}.
20684 @deftypevr {@code{dovecot-configuration} parameter} boolean mmap-disable?
20685 Don't use @code{mmap()} at all. This is required if you store indexes to
20686 shared file systems (NFS or clustered file system).
20687 Defaults to @samp{#f}.
20690 @deftypevr {@code{dovecot-configuration} parameter} boolean dotlock-use-excl?
20691 Rely on @samp{O_EXCL} to work when creating dotlock files. NFS
20692 supports @samp{O_EXCL} since version 3, so this should be safe to use
20693 nowadays by default.
20694 Defaults to @samp{#t}.
20697 @deftypevr {@code{dovecot-configuration} parameter} string mail-fsync
20698 When to use fsync() or fdatasync() calls:
20701 Whenever necessary to avoid losing important data
20703 Useful with e.g.@: NFS when @code{write()}s are delayed
20705 Never use it (best performance, but crashes can lose data).
20707 Defaults to @samp{"optimized"}.
20710 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-storage?
20711 Mail storage exists in NFS@. Set this to yes to make Dovecot flush
20712 NFS caches whenever needed. If you're using only a single mail server
20714 Defaults to @samp{#f}.
20717 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-nfs-index?
20718 Mail index files also exist in NFS@. Setting this to yes requires
20719 @samp{mmap-disable? #t} and @samp{fsync-disable? #f}.
20720 Defaults to @samp{#f}.
20723 @deftypevr {@code{dovecot-configuration} parameter} string lock-method
20724 Locking method for index files. Alternatives are fcntl, flock and
20725 dotlock. Dotlocking uses some tricks which may create more disk I/O
20726 than other locking methods. NFS users: flock doesn't work, remember to
20727 change @samp{mmap-disable}.
20728 Defaults to @samp{"fcntl"}.
20731 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-temp-dir
20732 Directory in which LDA/LMTP temporarily stores incoming mails >128
20734 Defaults to @samp{"/tmp"}.
20737 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-uid
20738 Valid UID range for users. This is mostly to make sure that users can't
20739 log in as daemons or other system users. Note that denying root logins is
20740 hardcoded to dovecot binary and can't be done even if @samp{first-valid-uid}
20742 Defaults to @samp{500}.
20745 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-uid
20747 Defaults to @samp{0}.
20750 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer first-valid-gid
20751 Valid GID range for users. Users having non-valid GID as primary group ID
20752 aren't allowed to log in. If user belongs to supplementary groups with
20753 non-valid GIDs, those groups are not set.
20754 Defaults to @samp{1}.
20757 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer last-valid-gid
20759 Defaults to @samp{0}.
20762 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-max-keyword-length
20763 Maximum allowed length for mail keyword name. It's only forced when
20764 trying to create new keywords.
20765 Defaults to @samp{50}.
20768 @deftypevr {@code{dovecot-configuration} parameter} colon-separated-file-name-list valid-chroot-dirs
20769 List of directories under which chrooting is allowed for mail
20770 processes (i.e.@: @file{/var/mail} will allow chrooting to @file{/var/mail/foo/bar}
20771 too). This setting doesn't affect @samp{login-chroot}
20772 @samp{mail-chroot} or auth chroot settings. If this setting is empty,
20773 @samp{/./} in home dirs are ignored. WARNING: Never add directories here
20774 which local users can modify, that may lead to root exploit. Usually
20775 this should be done only if you don't allow shell access for users.
20776 <doc/wiki/Chrooting.txt>.
20777 Defaults to @samp{()}.
20780 @deftypevr {@code{dovecot-configuration} parameter} string mail-chroot
20781 Default chroot directory for mail processes. This can be overridden
20782 for specific users in user database by giving @samp{/./} in user's home
20783 directory (e.g.@: @samp{/home/./user} chroots into @file{/home}). Note that usually
20784 there is no real need to do chrooting, Dovecot doesn't allow users to
20785 access files outside their mail directory anyway. If your home
20786 directories are prefixed with the chroot directory, append @samp{/.} to
20787 @samp{mail-chroot}. <doc/wiki/Chrooting.txt>.
20788 Defaults to @samp{""}.
20791 @deftypevr {@code{dovecot-configuration} parameter} file-name auth-socket-path
20792 UNIX socket path to master authentication server to find users.
20793 This is used by imap (for shared users) and lda.
20794 Defaults to @samp{"/var/run/dovecot/auth-userdb"}.
20797 @deftypevr {@code{dovecot-configuration} parameter} file-name mail-plugin-dir
20798 Directory where to look up mail plugins.
20799 Defaults to @samp{"/usr/lib/dovecot"}.
20802 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mail-plugins
20803 List of plugins to load for all services. Plugins specific to IMAP,
20804 LDA, etc.@: are added to this list in their own .conf files.
20805 Defaults to @samp{()}.
20808 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-cache-min-mail-count
20809 The minimum number of mails in a mailbox before updates are done to
20810 cache file. This allows optimizing Dovecot's behavior to do less disk
20811 writes at the cost of more disk reads.
20812 Defaults to @samp{0}.
20815 @deftypevr {@code{dovecot-configuration} parameter} string mailbox-idle-check-interval
20816 When IDLE command is running, mailbox is checked once in a while to
20817 see if there are any new mails or other changes. This setting defines
20818 the minimum time to wait between those checks. Dovecot can also use
20819 dnotify, inotify and kqueue to find out immediately when changes
20821 Defaults to @samp{"30 secs"}.
20824 @deftypevr {@code{dovecot-configuration} parameter} boolean mail-save-crlf?
20825 Save mails with CR+LF instead of plain LF@. This makes sending those
20826 mails take less CPU, especially with sendfile() syscall with Linux and
20827 FreeBSD@. But it also creates a bit more disk I/O which may just make it
20828 slower. Also note that if other software reads the mboxes/maildirs,
20829 they may handle the extra CRs wrong and cause problems.
20830 Defaults to @samp{#f}.
20833 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-stat-dirs?
20834 By default LIST command returns all entries in maildir beginning
20835 with a dot. Enabling this option makes Dovecot return only entries
20836 which are directories. This is done by stat()ing each entry, so it
20837 causes more disk I/O.
20838 (For systems setting struct @samp{dirent->d_type} this check is free
20839 and it's done always regardless of this setting).
20840 Defaults to @samp{#f}.
20843 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-copy-with-hardlinks?
20844 When copying a message, do it with hard links whenever possible.
20845 This makes the performance much better, and it's unlikely to have any
20847 Defaults to @samp{#t}.
20850 @deftypevr {@code{dovecot-configuration} parameter} boolean maildir-very-dirty-syncs?
20851 Assume Dovecot is the only MUA accessing Maildir: Scan cur/
20852 directory only when its mtime changes unexpectedly or when we can't find
20853 the mail otherwise.
20854 Defaults to @samp{#f}.
20857 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-read-locks
20858 Which locking methods to use for locking mbox. There are four
20863 Create <mailbox>.lock file. This is the oldest and most NFS-safe
20864 solution. If you want to use /var/mail/ like directory, the users will
20865 need write access to that directory.
20867 Same as dotlock, but if it fails because of permissions or because there
20868 isn't enough disk space, just skip it.
20870 Use this if possible. Works with NFS too if lockd is used.
20872 May not exist in all systems. Doesn't work with NFS.
20874 May not exist in all systems. Doesn't work with NFS.
20877 You can use multiple locking methods; if you do the order they're declared
20878 in is important to avoid deadlocks if other MTAs/MUAs are using multiple
20879 locking methods as well. Some operating systems don't allow using some of
20880 them simultaneously.
20883 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list mbox-write-locks
20887 @deftypevr {@code{dovecot-configuration} parameter} string mbox-lock-timeout
20888 Maximum time to wait for lock (all of them) before aborting.
20889 Defaults to @samp{"5 mins"}.
20892 @deftypevr {@code{dovecot-configuration} parameter} string mbox-dotlock-change-timeout
20893 If dotlock exists but the mailbox isn't modified in any way,
20894 override the lock file after this much time.
20895 Defaults to @samp{"2 mins"}.
20898 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-dirty-syncs?
20899 When mbox changes unexpectedly we have to fully read it to find out
20900 what changed. If the mbox is large this can take a long time. Since
20901 the change is usually just a newly appended mail, it'd be faster to
20902 simply read the new mails. If this setting is enabled, Dovecot does
20903 this but still safely fallbacks to re-reading the whole mbox file
20904 whenever something in mbox isn't how it's expected to be. The only real
20905 downside to this setting is that if some other MUA changes message
20906 flags, Dovecot doesn't notice it immediately. Note that a full sync is
20907 done with SELECT, EXAMINE, EXPUNGE and CHECK commands.
20908 Defaults to @samp{#t}.
20911 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-very-dirty-syncs?
20912 Like @samp{mbox-dirty-syncs}, but don't do full syncs even with SELECT,
20913 EXAMINE, EXPUNGE or CHECK commands. If this is set,
20914 @samp{mbox-dirty-syncs} is ignored.
20915 Defaults to @samp{#f}.
20918 @deftypevr {@code{dovecot-configuration} parameter} boolean mbox-lazy-writes?
20919 Delay writing mbox headers until doing a full write sync (EXPUNGE
20920 and CHECK commands and when closing the mailbox). This is especially
20921 useful for POP3 where clients often delete all mails. The downside is
20922 that our changes aren't immediately visible to other MUAs.
20923 Defaults to @samp{#t}.
20926 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mbox-min-index-size
20927 If mbox size is smaller than this (e.g.@: 100k), don't write index
20928 files. If an index file already exists it's still read, just not
20930 Defaults to @samp{0}.
20933 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mdbox-rotate-size
20934 Maximum dbox file size until it's rotated.
20935 Defaults to @samp{10000000}.
20938 @deftypevr {@code{dovecot-configuration} parameter} string mdbox-rotate-interval
20939 Maximum dbox file age until it's rotated. Typically in days. Day
20940 begins from midnight, so 1d = today, 2d = yesterday, etc. 0 = check
20942 Defaults to @samp{"1d"}.
20945 @deftypevr {@code{dovecot-configuration} parameter} boolean mdbox-preallocate-space?
20946 When creating new mdbox files, immediately preallocate their size to
20947 @samp{mdbox-rotate-size}. This setting currently works only in Linux
20948 with some file systems (ext4, xfs).
20949 Defaults to @samp{#f}.
20952 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-dir
20953 sdbox and mdbox support saving mail attachments to external files,
20954 which also allows single instance storage for them. Other backends
20955 don't support this for now.
20957 WARNING: This feature hasn't been tested much yet. Use at your own risk.
20959 Directory root where to store mail attachments. Disabled, if empty.
20960 Defaults to @samp{""}.
20963 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer mail-attachment-min-size
20964 Attachments smaller than this aren't saved externally. It's also
20965 possible to write a plugin to disable saving specific attachments
20967 Defaults to @samp{128000}.
20970 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-fs
20971 File system backend to use for saving attachments:
20974 No SiS done by Dovecot (but this might help FS's own deduplication)
20976 SiS with immediate byte-by-byte comparison during saving
20977 @item sis-queue posix
20978 SiS with delayed comparison and deduplication.
20980 Defaults to @samp{"sis posix"}.
20983 @deftypevr {@code{dovecot-configuration} parameter} string mail-attachment-hash
20984 Hash format to use in attachment filenames. You can add any text and
20985 variables: @code{%@{md4@}}, @code{%@{md5@}}, @code{%@{sha1@}},
20986 @code{%@{sha256@}}, @code{%@{sha512@}}, @code{%@{size@}}. Variables can be
20987 truncated, e.g.@: @code{%@{sha256:80@}} returns only first 80 bits.
20988 Defaults to @samp{"%@{sha1@}"}.
20991 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-process-limit
20993 Defaults to @samp{100}.
20996 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-client-limit
20998 Defaults to @samp{1000}.
21001 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer default-vsz-limit
21002 Default VSZ (virtual memory size) limit for service processes.
21003 This is mainly intended to catch and kill processes that leak memory
21004 before they eat up everything.
21005 Defaults to @samp{256000000}.
21008 @deftypevr {@code{dovecot-configuration} parameter} string default-login-user
21009 Login user is internally used by login processes. This is the most
21010 untrusted user in Dovecot system. It shouldn't have access to anything
21012 Defaults to @samp{"dovenull"}.
21015 @deftypevr {@code{dovecot-configuration} parameter} string default-internal-user
21016 Internal user is used by unprivileged processes. It should be
21017 separate from login user, so that login processes can't disturb other
21019 Defaults to @samp{"dovecot"}.
21022 @deftypevr {@code{dovecot-configuration} parameter} string ssl?
21023 SSL/TLS support: yes, no, required. <doc/wiki/SSL.txt>.
21024 Defaults to @samp{"required"}.
21027 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert
21028 PEM encoded X.509 SSL/TLS certificate (public key).
21029 Defaults to @samp{"</etc/dovecot/default.pem"}.
21032 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key
21033 PEM encoded SSL/TLS private key. The key is opened before
21034 dropping root privileges, so keep the key file unreadable by anyone but
21036 Defaults to @samp{"</etc/dovecot/private/default.pem"}.
21039 @deftypevr {@code{dovecot-configuration} parameter} string ssl-key-password
21040 If key file is password protected, give the password here.
21041 Alternatively give it when starting dovecot with -p parameter. Since
21042 this file is often world-readable, you may want to place this setting
21043 instead to a different.
21044 Defaults to @samp{""}.
21047 @deftypevr {@code{dovecot-configuration} parameter} string ssl-ca
21048 PEM encoded trusted certificate authority. Set this only if you
21049 intend to use @samp{ssl-verify-client-cert? #t}. The file should
21050 contain the CA certificate(s) followed by the matching
21051 CRL(s). (e.g.@: @samp{ssl-ca </etc/ssl/certs/ca.pem}).
21052 Defaults to @samp{""}.
21055 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-require-crl?
21056 Require that CRL check succeeds for client certificates.
21057 Defaults to @samp{#t}.
21060 @deftypevr {@code{dovecot-configuration} parameter} boolean ssl-verify-client-cert?
21061 Request client to send a certificate. If you also want to require
21062 it, set @samp{auth-ssl-require-client-cert? #t} in auth section.
21063 Defaults to @samp{#f}.
21066 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cert-username-field
21067 Which field from certificate to use for username. commonName and
21068 x500UniqueIdentifier are the usual choices. You'll also need to set
21069 @samp{auth-ssl-username-from-cert? #t}.
21070 Defaults to @samp{"commonName"}.
21073 @deftypevr {@code{dovecot-configuration} parameter} string ssl-min-protocol
21074 Minimum SSL protocol version to accept.
21075 Defaults to @samp{"TLSv1"}.
21078 @deftypevr {@code{dovecot-configuration} parameter} string ssl-cipher-list
21079 SSL ciphers to use.
21080 Defaults to @samp{"ALL:!kRSA:!SRP:!kDHd:!DSS:!aNULL:!eNULL:!EXPORT:!DES:!3DES:!MD5:!PSK:!RC4:!ADH:!LOW@@STRENGTH"}.
21083 @deftypevr {@code{dovecot-configuration} parameter} string ssl-crypto-device
21084 SSL crypto device to use, for valid values run "openssl engine".
21085 Defaults to @samp{""}.
21088 @deftypevr {@code{dovecot-configuration} parameter} string postmaster-address
21089 Address to use when sending rejection mails.
21090 %d expands to recipient domain.
21091 Defaults to @samp{"postmaster@@%d"}.
21094 @deftypevr {@code{dovecot-configuration} parameter} string hostname
21095 Hostname to use in various parts of sent mails (e.g.@: in Message-Id)
21096 and in LMTP replies. Default is the system's real hostname@@domain.
21097 Defaults to @samp{""}.
21100 @deftypevr {@code{dovecot-configuration} parameter} boolean quota-full-tempfail?
21101 If user is over quota, return with temporary failure instead of
21103 Defaults to @samp{#f}.
21106 @deftypevr {@code{dovecot-configuration} parameter} file-name sendmail-path
21107 Binary to use for sending mails.
21108 Defaults to @samp{"/usr/sbin/sendmail"}.
21111 @deftypevr {@code{dovecot-configuration} parameter} string submission-host
21112 If non-empty, send mails via this SMTP host[:port] instead of
21114 Defaults to @samp{""}.
21117 @deftypevr {@code{dovecot-configuration} parameter} string rejection-subject
21118 Subject: header to use for rejection mails. You can use the same
21119 variables as for @samp{rejection-reason} below.
21120 Defaults to @samp{"Rejected: %s"}.
21123 @deftypevr {@code{dovecot-configuration} parameter} string rejection-reason
21124 Human readable error message for rejection mails. You can use
21137 Defaults to @samp{"Your message to <%t> was automatically rejected:%n%r"}.
21140 @deftypevr {@code{dovecot-configuration} parameter} string recipient-delimiter
21141 Delimiter character between local-part and detail in email
21143 Defaults to @samp{"+"}.
21146 @deftypevr {@code{dovecot-configuration} parameter} string lda-original-recipient-header
21147 Header where the original recipient address (SMTP's RCPT TO:
21148 address) is taken from if not available elsewhere. With dovecot-lda -a
21149 parameter overrides this. A commonly used header for this is
21151 Defaults to @samp{""}.
21154 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autocreate?
21155 Should saving a mail to a nonexistent mailbox automatically create
21157 Defaults to @samp{#f}.
21160 @deftypevr {@code{dovecot-configuration} parameter} boolean lda-mailbox-autosubscribe?
21161 Should automatically created mailboxes be also automatically
21163 Defaults to @samp{#f}.
21166 @deftypevr {@code{dovecot-configuration} parameter} non-negative-integer imap-max-line-length
21167 Maximum IMAP command line length. Some clients generate very long
21168 command lines with huge mailboxes, so you may need to raise this if you
21169 get "Too long argument" or "IMAP command line too large" errors
21171 Defaults to @samp{64000}.
21174 @deftypevr {@code{dovecot-configuration} parameter} string imap-logout-format
21175 IMAP logout format string:
21178 total number of bytes read from client
21180 total number of bytes sent to client.
21182 See @file{doc/wiki/Variables.txt} for a list of all the variables you can use.
21183 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@}"}.
21186 @deftypevr {@code{dovecot-configuration} parameter} string imap-capability
21187 Override the IMAP CAPABILITY response. If the value begins with '+',
21188 add the given capabilities on top of the defaults (e.g.@: +XFOO XBAR).
21189 Defaults to @samp{""}.
21192 @deftypevr {@code{dovecot-configuration} parameter} string imap-idle-notify-interval
21193 How long to wait between "OK Still here" notifications when client
21195 Defaults to @samp{"2 mins"}.
21198 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-send
21199 ID field names and values to send to clients. Using * as the value
21200 makes Dovecot use the default value. The following fields have default
21201 values currently: name, version, os, os-version, support-url,
21203 Defaults to @samp{""}.
21206 @deftypevr {@code{dovecot-configuration} parameter} string imap-id-log
21207 ID fields sent by client to log. * means everything.
21208 Defaults to @samp{""}.
21211 @deftypevr {@code{dovecot-configuration} parameter} space-separated-string-list imap-client-workarounds
21212 Workarounds for various client bugs:
21215 @item delay-newmail
21216 Send EXISTS/RECENT new mail notifications only when replying to NOOP and
21217 CHECK commands. Some clients ignore them otherwise, for example OSX
21218 Mail (<v2.1). Outlook Express breaks more badly though, without this it
21219 may show user "Message no longer in server" errors. Note that OE6
21220 still breaks even with this workaround if synchronization is set to
21223 @item tb-extra-mailbox-sep
21224 Thunderbird gets somehow confused with LAYOUT=fs (mbox and dbox) and
21225 adds extra @samp{/} suffixes to mailbox names. This option causes Dovecot to
21226 ignore the extra @samp{/} instead of treating it as invalid mailbox name.
21228 @item tb-lsub-flags
21229 Show \Noselect flags for LSUB replies with LAYOUT=fs (e.g.@: mbox).
21230 This makes Thunderbird realize they aren't selectable and show them
21231 greyed out, instead of only later giving "not selectable" popup error.
21233 Defaults to @samp{()}.
21236 @deftypevr {@code{dovecot-configuration} parameter} string imap-urlauth-host
21237 Host allowed in URLAUTH URLs sent by client. "*" allows all.
21238 Defaults to @samp{""}.
21242 Whew! Lots of configuration options. The nice thing about it though is
21243 that Guix has a complete interface to Dovecot's configuration
21244 language. This allows not only a nice way to declare configurations,
21245 but also offers reflective capabilities as well: users can write code to
21246 inspect and transform configurations from within Scheme.
21248 However, it could be that you just want to get a @code{dovecot.conf} up
21249 and running. In that case, you can pass an
21250 @code{opaque-dovecot-configuration} as the @code{#:config} parameter to
21251 @code{dovecot-service}. As its name indicates, an opaque configuration
21252 does not have easy reflective capabilities.
21254 Available @code{opaque-dovecot-configuration} fields are:
21256 @deftypevr {@code{opaque-dovecot-configuration} parameter} package dovecot
21257 The dovecot package.
21260 @deftypevr {@code{opaque-dovecot-configuration} parameter} string string
21261 The contents of the @code{dovecot.conf}, as a string.
21264 For example, if your @code{dovecot.conf} is just the empty string, you
21265 could instantiate a dovecot service like this:
21268 (dovecot-service #:config
21269 (opaque-dovecot-configuration
21273 @subsubheading OpenSMTPD Service
21275 @deffn {Scheme Variable} opensmtpd-service-type
21276 This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
21277 service, whose value should be an @code{opensmtpd-configuration} object
21278 as in this example:
21281 (service opensmtpd-service-type
21282 (opensmtpd-configuration
21283 (config-file (local-file "./my-smtpd.conf"))))
21287 @deftp {Data Type} opensmtpd-configuration
21288 Data type representing the configuration of opensmtpd.
21291 @item @code{package} (default: @var{opensmtpd})
21292 Package object of the OpenSMTPD SMTP server.
21294 @item @code{config-file} (default: @code{%default-opensmtpd-file})
21295 File-like object of the OpenSMTPD configuration file to use. By default
21296 it listens on the loopback network interface, and allows for mail from
21297 users and daemons on the local machine, as well as permitting email to
21298 remote servers. Run @command{man smtpd.conf} for more information.
21303 @subsubheading Exim Service
21305 @cindex mail transfer agent (MTA)
21306 @cindex MTA (mail transfer agent)
21309 @deffn {Scheme Variable} exim-service-type
21310 This is the type of the @uref{https://exim.org, Exim} mail transfer
21311 agent (MTA), whose value should be an @code{exim-configuration} object
21312 as in this example:
21315 (service exim-service-type
21316 (exim-configuration
21317 (config-file (local-file "./my-exim.conf"))))
21321 In order to use an @code{exim-service-type} service you must also have a
21322 @code{mail-aliases-service-type} service present in your
21323 @code{operating-system} (even if it has no aliases).
21325 @deftp {Data Type} exim-configuration
21326 Data type representing the configuration of exim.
21329 @item @code{package} (default: @var{exim})
21330 Package object of the Exim server.
21332 @item @code{config-file} (default: @code{#f})
21333 File-like object of the Exim configuration file to use. If its value is
21334 @code{#f} then use the default configuration file from the package
21335 provided in @code{package}. The resulting configuration file is loaded
21336 after setting the @code{exim_user} and @code{exim_group} configuration
21342 @subsubheading Getmail service
21347 @deffn {Scheme Variable} getmail-service-type
21348 This is the type of the @uref{http://pyropus.ca/software/getmail/, Getmail}
21349 mail retriever, whose value should be an @code{getmail-configuration}.
21352 Available @code{getmail-configuration} fields are:
21354 @deftypevr {@code{getmail-configuration} parameter} symbol name
21355 A symbol to identify the getmail service.
21357 Defaults to @samp{"unset"}.
21361 @deftypevr {@code{getmail-configuration} parameter} package package
21362 The getmail package to use.
21366 @deftypevr {@code{getmail-configuration} parameter} string user
21367 The user to run getmail as.
21369 Defaults to @samp{"getmail"}.
21373 @deftypevr {@code{getmail-configuration} parameter} string group
21374 The group to run getmail as.
21376 Defaults to @samp{"getmail"}.
21380 @deftypevr {@code{getmail-configuration} parameter} string directory
21381 The getmail directory to use.
21383 Defaults to @samp{"/var/lib/getmail/default"}.
21387 @deftypevr {@code{getmail-configuration} parameter} getmail-configuration-file rcfile
21388 The getmail configuration file to use.
21390 Available @code{getmail-configuration-file} fields are:
21392 @deftypevr {@code{getmail-configuration-file} parameter} getmail-retriever-configuration retriever
21393 What mail account to retrieve mail from, and how to access that account.
21395 Available @code{getmail-retriever-configuration} fields are:
21397 @deftypevr {@code{getmail-retriever-configuration} parameter} string type
21398 The type of mail retriever to use. Valid values include @samp{passwd}
21401 Defaults to @samp{"SimpleIMAPSSLRetriever"}.
21405 @deftypevr {@code{getmail-retriever-configuration} parameter} string server
21406 Username to login to the mail server with.
21408 Defaults to @samp{unset}.
21412 @deftypevr {@code{getmail-retriever-configuration} parameter} string username
21413 Username to login to the mail server with.
21415 Defaults to @samp{unset}.
21419 @deftypevr {@code{getmail-retriever-configuration} parameter} non-negative-integer port
21420 Port number to connect to.
21422 Defaults to @samp{#f}.
21426 @deftypevr {@code{getmail-retriever-configuration} parameter} string password
21427 Override fields from passwd.
21429 Defaults to @samp{""}.
21433 @deftypevr {@code{getmail-retriever-configuration} parameter} list password-command
21434 Override fields from passwd.
21436 Defaults to @samp{()}.
21440 @deftypevr {@code{getmail-retriever-configuration} parameter} string keyfile
21441 PEM-formatted key file to use for the TLS negotiation.
21443 Defaults to @samp{""}.
21447 @deftypevr {@code{getmail-retriever-configuration} parameter} string certfile
21448 PEM-formatted certificate file to use for the TLS negotiation.
21450 Defaults to @samp{""}.
21454 @deftypevr {@code{getmail-retriever-configuration} parameter} string ca-certs
21455 CA certificates to use.
21457 Defaults to @samp{""}.
21461 @deftypevr {@code{getmail-retriever-configuration} parameter} parameter-alist extra-parameters
21462 Extra retriever parameters.
21464 Defaults to @samp{()}.
21470 @deftypevr {@code{getmail-configuration-file} parameter} getmail-destination-configuration destination
21471 What to do with retrieved messages.
21473 Available @code{getmail-destination-configuration} fields are:
21475 @deftypevr {@code{getmail-destination-configuration} parameter} string type
21476 The type of mail destination. Valid values include @samp{Maildir},
21477 @samp{Mboxrd} and @samp{MDA_external}.
21479 Defaults to @samp{unset}.
21483 @deftypevr {@code{getmail-destination-configuration} parameter} string-or-filelike path
21484 The path option for the mail destination. The behaviour depends on the
21487 Defaults to @samp{""}.
21491 @deftypevr {@code{getmail-destination-configuration} parameter} parameter-alist extra-parameters
21492 Extra destination parameters
21494 Defaults to @samp{()}.
21500 @deftypevr {@code{getmail-configuration-file} parameter} getmail-options-configuration options
21503 Available @code{getmail-options-configuration} fields are:
21505 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer verbose
21506 If set to @samp{0}, getmail will only print warnings and errors. A
21507 value of @samp{1} means that messages will be printed about retrieving
21508 and deleting messages. If set to @samp{2}, getmail will print messages
21509 about each of it's actions.
21511 Defaults to @samp{1}.
21515 @deftypevr {@code{getmail-options-configuration} parameter} boolean read-all
21516 If true, getmail will retrieve all available messages. Otherwise it
21517 will only retrieve messages it hasn't seen previously.
21519 Defaults to @samp{#t}.
21523 @deftypevr {@code{getmail-options-configuration} parameter} boolean delete
21524 If set to true, messages will be deleted from the server after
21525 retrieving and successfully delivering them. Otherwise, messages will
21526 be left on the server.
21528 Defaults to @samp{#f}.
21532 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-after
21533 Getmail will delete messages this number of days after seeing them, if
21534 they have been delivered. This means messages will be left on the
21535 server this number of days after delivering them. A value of @samp{0}
21536 disabled this feature.
21538 Defaults to @samp{0}.
21542 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer delete-bigger-than
21543 Delete messages larger than this of bytes after retrieving them, even if
21544 the delete and delete-after options are disabled. A value of @samp{0}
21545 disables this feature.
21547 Defaults to @samp{0}.
21551 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-bytes-per-session
21552 Retrieve messages totalling up to this number of bytes before closing
21553 the session with the server. A value of @samp{0} disables this feature.
21555 Defaults to @samp{0}.
21559 @deftypevr {@code{getmail-options-configuration} parameter} non-negative-integer max-message-size
21560 Don't retrieve messages larger than this number of bytes. A value of
21561 @samp{0} disables this feature.
21563 Defaults to @samp{0}.
21567 @deftypevr {@code{getmail-options-configuration} parameter} boolean delivered-to
21568 If true, getmail will add a Delivered-To header to messages.
21570 Defaults to @samp{#t}.
21574 @deftypevr {@code{getmail-options-configuration} parameter} boolean received
21575 If set, getmail adds a Received header to the messages.
21577 Defaults to @samp{#t}.
21581 @deftypevr {@code{getmail-options-configuration} parameter} string message-log
21582 Getmail will record a log of its actions to the named file. A value of
21583 @samp{""} disables this feature.
21585 Defaults to @samp{""}.
21589 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-syslog
21590 If true, getmail will record a log of its actions using the system
21593 Defaults to @samp{#f}.
21597 @deftypevr {@code{getmail-options-configuration} parameter} boolean message-log-verbose
21598 If true, getmail will log information about messages not retrieved and
21599 the reason for not retrieving them, as well as starting and ending
21602 Defaults to @samp{#f}.
21606 @deftypevr {@code{getmail-options-configuration} parameter} parameter-alist extra-parameters
21607 Extra options to include.
21609 Defaults to @samp{()}.
21617 @deftypevr {@code{getmail-configuration} parameter} list idle
21618 A list of mailboxes that getmail should wait on the server for new mail
21619 notifications. This depends on the server supporting the IDLE
21622 Defaults to @samp{()}.
21626 @deftypevr {@code{getmail-configuration} parameter} list environment-variables
21627 Environment variables to set for getmail.
21629 Defaults to @samp{()}.
21633 @subsubheading Mail Aliases Service
21635 @cindex email aliases
21636 @cindex aliases, for email addresses
21638 @deffn {Scheme Variable} mail-aliases-service-type
21639 This is the type of the service which provides @code{/etc/aliases},
21640 specifying how to deliver mail to users on this system.
21643 (service mail-aliases-service-type
21644 '(("postmaster" "bob")
21645 ("bob" "bob@@example.com" "bob@@example2.com")))
21649 The configuration for a @code{mail-aliases-service-type} service is an
21650 association list denoting how to deliver mail that comes to this
21651 system. Each entry is of the form @code{(alias addresses ...)}, with
21652 @code{alias} specifying the local alias and @code{addresses} specifying
21653 where to deliver this user's mail.
21655 The aliases aren't required to exist as users on the local system. In
21656 the above example, there doesn't need to be a @code{postmaster} entry in
21657 the @code{operating-system}'s @code{user-accounts} in order to deliver
21658 the @code{postmaster} mail to @code{bob} (which subsequently would
21659 deliver mail to @code{bob@@example.com} and @code{bob@@example2.com}).
21661 @subsubheading GNU Mailutils IMAP4 Daemon
21662 @cindex GNU Mailutils IMAP4 Daemon
21664 @deffn {Scheme Variable} imap4d-service-type
21665 This is the type of the GNU Mailutils IMAP4 Daemon (@pxref{imap4d,,,
21666 mailutils, GNU Mailutils Manual}), whose value should be an
21667 @code{imap4d-configuration} object as in this example:
21670 (service imap4d-service-type
21671 (imap4d-configuration
21672 (config-file (local-file "imap4d.conf"))))
21676 @deftp {Data Type} imap4d-configuration
21677 Data type representing the configuration of @command{imap4d}.
21680 @item @code{package} (default: @code{mailutils})
21681 The package that provides @command{imap4d}.
21683 @item @code{config-file} (default: @code{%default-imap4d-config-file})
21684 File-like object of the configuration file to use, by default it will listen
21685 on TCP port 143 of @code{localhost}. @xref{Conf-imap4d,,, mailutils, GNU
21686 Mailutils Manual}, for details.
21691 @subsubheading Radicale Service
21695 @deffn {Scheme Variable} radicale-service-type
21696 This is the type of the @uref{https://radicale.org, Radicale} CalDAV/CardDAV
21697 server whose value should be a @code{radicale-configuration}.
21700 @deftp {Data Type} radicale-configuration
21701 Data type representing the configuration of @command{radicale}.
21704 @item @code{package} (default: @code{radicale})
21705 The package that provides @command{radicale}.
21707 @item @code{config-file} (default: @code{%default-radicale-config-file})
21708 File-like object of the configuration file to use, by default it will listen
21709 on TCP port 5232 of @code{localhost} and use the @code{htpasswd} file at
21710 @file{/var/lib/radicale/users} with no (@code{plain}) encryption.
21715 @node Messaging Services
21716 @subsection Messaging Services
21721 The @code{(gnu services messaging)} module provides Guix service
21722 definitions for messaging services. Currently it provides the following
21725 @subsubheading Prosody Service
21727 @deffn {Scheme Variable} prosody-service-type
21728 This is the type for the @uref{https://prosody.im, Prosody XMPP
21729 communication server}. Its value must be a @code{prosody-configuration}
21730 record as in this example:
21733 (service prosody-service-type
21734 (prosody-configuration
21735 (modules-enabled (cons* "groups" "mam" %default-modules-enabled))
21738 (int-component-configuration
21739 (hostname "conference.example.net")
21741 (mod-muc (mod-muc-configuration)))))
21744 (virtualhost-configuration
21745 (domain "example.net"))))))
21748 See below for details about @code{prosody-configuration}.
21752 By default, Prosody does not need much configuration. Only one
21753 @code{virtualhosts} field is needed: it specifies the domain you wish
21756 You can perform various sanity checks on the generated configuration
21757 with the @code{prosodyctl check} command.
21759 Prosodyctl will also help you to import certificates from the
21760 @code{letsencrypt} directory so that the @code{prosody} user can access
21761 them. See @url{https://prosody.im/doc/letsencrypt}.
21764 prosodyctl --root cert import /etc/letsencrypt/live
21767 The available configuration parameters follow. Each parameter
21768 definition is preceded by its type; for example, @samp{string-list foo}
21769 indicates that the @code{foo} parameter should be specified as a list of
21770 strings. Types starting with @code{maybe-} denote parameters that won't
21771 show up in @code{prosody.cfg.lua} when their value is @code{'disabled}.
21773 There is also a way to specify the configuration as a string, if you
21774 have an old @code{prosody.cfg.lua} file that you want to port over from
21775 some other system; see the end for more details.
21777 The @code{file-object} type designates either a file-like object
21778 (@pxref{G-Expressions, file-like objects}) or a file name.
21780 @c The following documentation was initially generated by
21781 @c (generate-documentation) in (gnu services messaging). Manually maintained
21782 @c documentation is better, so we shouldn't hesitate to edit below as
21783 @c needed. However if the change you want to make to this documentation
21784 @c can be done in an automated way, it's probably easier to change
21785 @c (generate-documentation) than to make it below and have to deal with
21786 @c the churn as Prosody updates.
21788 Available @code{prosody-configuration} fields are:
21790 @deftypevr {@code{prosody-configuration} parameter} package prosody
21791 The Prosody package.
21794 @deftypevr {@code{prosody-configuration} parameter} file-name data-path
21795 Location of the Prosody data storage directory. See
21796 @url{https://prosody.im/doc/configure}.
21797 Defaults to @samp{"/var/lib/prosody"}.
21800 @deftypevr {@code{prosody-configuration} parameter} file-object-list plugin-paths
21801 Additional plugin directories. They are searched in all the specified
21802 paths in order. See @url{https://prosody.im/doc/plugins_directory}.
21803 Defaults to @samp{()}.
21806 @deftypevr {@code{prosody-configuration} parameter} file-name certificates
21807 Every virtual host and component needs a certificate so that clients and
21808 servers can securely verify its identity. Prosody will automatically load
21809 certificates/keys from the directory specified here.
21810 Defaults to @samp{"/etc/prosody/certs"}.
21813 @deftypevr {@code{prosody-configuration} parameter} string-list admins
21814 This is a list of accounts that are admins for the server. Note that you
21815 must create the accounts separately. See @url{https://prosody.im/doc/admins} and
21816 @url{https://prosody.im/doc/creating_accounts}.
21817 Example: @code{(admins '("user1@@example.com" "user2@@example.net"))}
21818 Defaults to @samp{()}.
21821 @deftypevr {@code{prosody-configuration} parameter} boolean use-libevent?
21822 Enable use of libevent for better performance under high load. See
21823 @url{https://prosody.im/doc/libevent}.
21824 Defaults to @samp{#f}.
21827 @deftypevr {@code{prosody-configuration} parameter} module-list modules-enabled
21828 This is the list of modules Prosody will load on startup. It looks for
21829 @code{mod_modulename.lua} in the plugins folder, so make sure that exists too.
21830 Documentation on modules can be found at:
21831 @url{https://prosody.im/doc/modules}.
21832 Defaults to @samp{("roster" "saslauth" "tls" "dialback" "disco" "carbons" "private" "blocklist" "vcard" "version" "uptime" "time" "ping" "pep" "register" "admin_adhoc")}.
21835 @deftypevr {@code{prosody-configuration} parameter} string-list modules-disabled
21836 @samp{"offline"}, @samp{"c2s"} and @samp{"s2s"} are auto-loaded, but
21837 should you want to disable them then add them to this list.
21838 Defaults to @samp{()}.
21841 @deftypevr {@code{prosody-configuration} parameter} file-object groups-file
21842 Path to a text file where the shared groups are defined. If this path is
21843 empty then @samp{mod_groups} does nothing. See
21844 @url{https://prosody.im/doc/modules/mod_groups}.
21845 Defaults to @samp{"/var/lib/prosody/sharedgroups.txt"}.
21848 @deftypevr {@code{prosody-configuration} parameter} boolean allow-registration?
21849 Disable account creation by default, for security. See
21850 @url{https://prosody.im/doc/creating_accounts}.
21851 Defaults to @samp{#f}.
21854 @deftypevr {@code{prosody-configuration} parameter} maybe-ssl-configuration ssl
21855 These are the SSL/TLS-related settings. Most of them are disabled so to
21856 use Prosody's defaults. If you do not completely understand these options, do
21857 not add them to your config, it is easy to lower the security of your server
21858 using them. See @url{https://prosody.im/doc/advanced_ssl_config}.
21860 Available @code{ssl-configuration} fields are:
21862 @deftypevr {@code{ssl-configuration} parameter} maybe-string protocol
21863 This determines what handshake to use.
21866 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name key
21867 Path to your private key file.
21870 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name certificate
21871 Path to your certificate file.
21874 @deftypevr {@code{ssl-configuration} parameter} file-object capath
21875 Path to directory containing root certificates that you wish Prosody to
21876 trust when verifying the certificates of remote servers.
21877 Defaults to @samp{"/etc/ssl/certs"}.
21880 @deftypevr {@code{ssl-configuration} parameter} maybe-file-object cafile
21881 Path to a file containing root certificates that you wish Prosody to trust.
21882 Similar to @code{capath} but with all certificates concatenated together.
21885 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verify
21886 A list of verification options (these mostly map to OpenSSL's
21887 @code{set_verify()} flags).
21890 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list options
21891 A list of general options relating to SSL/TLS@. These map to OpenSSL's
21892 @code{set_options()}. For a full list of options available in LuaSec, see the
21896 @deftypevr {@code{ssl-configuration} parameter} maybe-non-negative-integer depth
21897 How long a chain of certificate authorities to check when looking for a
21898 trusted root certificate.
21901 @deftypevr {@code{ssl-configuration} parameter} maybe-string ciphers
21902 An OpenSSL cipher string. This selects what ciphers Prosody will offer to
21903 clients, and in what order.
21906 @deftypevr {@code{ssl-configuration} parameter} maybe-file-name dhparam
21907 A path to a file containing parameters for Diffie-Hellman key exchange. You
21908 can create such a file with:
21909 @code{openssl dhparam -out /etc/prosody/certs/dh-2048.pem 2048}
21912 @deftypevr {@code{ssl-configuration} parameter} maybe-string curve
21913 Curve for Elliptic curve Diffie-Hellman. Prosody's default is
21914 @samp{"secp384r1"}.
21917 @deftypevr {@code{ssl-configuration} parameter} maybe-string-list verifyext
21918 A list of ``extra'' verification options.
21921 @deftypevr {@code{ssl-configuration} parameter} maybe-string password
21922 Password for encrypted private keys.
21927 @deftypevr {@code{prosody-configuration} parameter} boolean c2s-require-encryption?
21928 Whether to force all client-to-server connections to be encrypted or not.
21929 See @url{https://prosody.im/doc/modules/mod_tls}.
21930 Defaults to @samp{#f}.
21933 @deftypevr {@code{prosody-configuration} parameter} string-list disable-sasl-mechanisms
21934 Set of mechanisms that will never be offered. See
21935 @url{https://prosody.im/doc/modules/mod_saslauth}.
21936 Defaults to @samp{("DIGEST-MD5")}.
21939 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-require-encryption?
21940 Whether to force all server-to-server connections to be encrypted or not.
21941 See @url{https://prosody.im/doc/modules/mod_tls}.
21942 Defaults to @samp{#f}.
21945 @deftypevr {@code{prosody-configuration} parameter} boolean s2s-secure-auth?
21946 Whether to require encryption and certificate authentication. This
21947 provides ideal security, but requires servers you communicate with to support
21948 encryption AND present valid, trusted certificates. See
21949 @url{https://prosody.im/doc/s2s#security}.
21950 Defaults to @samp{#f}.
21953 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-insecure-domains
21954 Many servers don't support encryption or have invalid or self-signed
21955 certificates. You can list domains here that will not be required to
21956 authenticate using certificates. They will be authenticated using DNS@. See
21957 @url{https://prosody.im/doc/s2s#security}.
21958 Defaults to @samp{()}.
21961 @deftypevr {@code{prosody-configuration} parameter} string-list s2s-secure-domains
21962 Even if you leave @code{s2s-secure-auth?} disabled, you can still require
21963 valid certificates for some domains by specifying a list here. See
21964 @url{https://prosody.im/doc/s2s#security}.
21965 Defaults to @samp{()}.
21968 @deftypevr {@code{prosody-configuration} parameter} string authentication
21969 Select the authentication backend to use. The default provider stores
21970 passwords in plaintext and uses Prosody's configured data storage to store the
21971 authentication data. If you do not trust your server please see
21972 @url{https://prosody.im/doc/modules/mod_auth_internal_hashed} for information
21973 about using the hashed backend. See also
21974 @url{https://prosody.im/doc/authentication}
21975 Defaults to @samp{"internal_plain"}.
21978 @deftypevr {@code{prosody-configuration} parameter} maybe-string log
21979 Set logging options. Advanced logging configuration is not yet supported
21980 by the Prosody service. See @url{https://prosody.im/doc/logging}.
21981 Defaults to @samp{"*syslog"}.
21984 @deftypevr {@code{prosody-configuration} parameter} file-name pidfile
21985 File to write pid in. See @url{https://prosody.im/doc/modules/mod_posix}.
21986 Defaults to @samp{"/var/run/prosody/prosody.pid"}.
21989 @deftypevr {@code{prosody-configuration} parameter} maybe-non-negative-integer http-max-content-size
21990 Maximum allowed size of the HTTP body (in bytes).
21993 @deftypevr {@code{prosody-configuration} parameter} maybe-string http-external-url
21994 Some modules expose their own URL in various ways. This URL is built
21995 from the protocol, host and port used. If Prosody sits behind a proxy, the
21996 public URL will be @code{http-external-url} instead. See
21997 @url{https://prosody.im/doc/http#external_url}.
22000 @deftypevr {@code{prosody-configuration} parameter} virtualhost-configuration-list virtualhosts
22001 A host in Prosody is a domain on which user accounts can be created. For
22002 example if you want your users to have addresses like
22003 @samp{"john.smith@@example.com"} then you need to add a host
22004 @samp{"example.com"}. All options in this list will apply only to this host.
22006 Note: the name @emph{virtual} host is used in configuration to avoid confusion with
22007 the actual physical host that Prosody is installed on. A single Prosody
22008 instance can serve many domains, each one defined as a VirtualHost entry in
22009 Prosody's configuration. Conversely a server that hosts a single domain would
22010 have just one VirtualHost entry.
22012 See @url{https://prosody.im/doc/configure#virtual_host_settings}.
22014 Available @code{virtualhost-configuration} fields are:
22016 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:
22017 @deftypevr {@code{virtualhost-configuration} parameter} string domain
22018 Domain you wish Prosody to serve.
22023 @deftypevr {@code{prosody-configuration} parameter} int-component-configuration-list int-components
22024 Components are extra services on a server which are available to clients,
22025 usually on a subdomain of the main server (such as
22026 @samp{"mycomponent.example.com"}). Example components might be chatroom
22027 servers, user directories, or gateways to other protocols.
22029 Internal components are implemented with Prosody-specific plugins. To add an
22030 internal component, you simply fill the hostname field, and the plugin you wish
22031 to use for the component.
22033 See @url{https://prosody.im/doc/components}.
22034 Defaults to @samp{()}.
22036 Available @code{int-component-configuration} fields are:
22038 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:
22039 @deftypevr {@code{int-component-configuration} parameter} string hostname
22040 Hostname of the component.
22043 @deftypevr {@code{int-component-configuration} parameter} string plugin
22044 Plugin you wish to use for the component.
22047 @deftypevr {@code{int-component-configuration} parameter} maybe-mod-muc-configuration mod-muc
22048 Multi-user chat (MUC) is Prosody's module for allowing you to create
22049 hosted chatrooms/conferences for XMPP users.
22051 General information on setting up and using multi-user chatrooms can be found
22052 in the ``Chatrooms'' documentation (@url{https://prosody.im/doc/chatrooms}),
22053 which you should read if you are new to XMPP chatrooms.
22055 See also @url{https://prosody.im/doc/modules/mod_muc}.
22057 Available @code{mod-muc-configuration} fields are:
22059 @deftypevr {@code{mod-muc-configuration} parameter} string name
22060 The name to return in service discovery responses.
22061 Defaults to @samp{"Prosody Chatrooms"}.
22064 @deftypevr {@code{mod-muc-configuration} parameter} string-or-boolean restrict-room-creation
22065 If @samp{#t}, this will only allow admins to create new chatrooms.
22066 Otherwise anyone can create a room. The value @samp{"local"} restricts room
22067 creation to users on the service's parent domain. E.g.@: @samp{user@@example.com}
22068 can create rooms on @samp{rooms.example.com}. The value @samp{"admin"}
22069 restricts to service administrators only.
22070 Defaults to @samp{#f}.
22073 @deftypevr {@code{mod-muc-configuration} parameter} non-negative-integer max-history-messages
22074 Maximum number of history messages that will be sent to the member that has
22075 just joined the room.
22076 Defaults to @samp{20}.
22083 @deftypevr {@code{prosody-configuration} parameter} ext-component-configuration-list ext-components
22084 External components use XEP-0114, which most standalone components
22085 support. To add an external component, you simply fill the hostname field. See
22086 @url{https://prosody.im/doc/components}.
22087 Defaults to @samp{()}.
22089 Available @code{ext-component-configuration} fields are:
22091 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:
22092 @deftypevr {@code{ext-component-configuration} parameter} string component-secret
22093 Password which the component will use to log in.
22096 @deftypevr {@code{ext-component-configuration} parameter} string hostname
22097 Hostname of the component.
22102 @deftypevr {@code{prosody-configuration} parameter} non-negative-integer-list component-ports
22103 Port(s) Prosody listens on for component connections.
22104 Defaults to @samp{(5347)}.
22107 @deftypevr {@code{prosody-configuration} parameter} string component-interface
22108 Interface Prosody listens on for component connections.
22109 Defaults to @samp{"127.0.0.1"}.
22112 @deftypevr {@code{prosody-configuration} parameter} maybe-raw-content raw-content
22113 Raw content that will be added to the configuration file.
22116 It could be that you just want to get a @code{prosody.cfg.lua}
22117 up and running. In that case, you can pass an
22118 @code{opaque-prosody-configuration} record as the value of
22119 @code{prosody-service-type}. As its name indicates, an opaque configuration
22120 does not have easy reflective capabilities.
22121 Available @code{opaque-prosody-configuration} fields are:
22123 @deftypevr {@code{opaque-prosody-configuration} parameter} package prosody
22124 The prosody package.
22127 @deftypevr {@code{opaque-prosody-configuration} parameter} string prosody.cfg.lua
22128 The contents of the @code{prosody.cfg.lua} to use.
22131 For example, if your @code{prosody.cfg.lua} is just the empty
22132 string, you could instantiate a prosody service like this:
22135 (service prosody-service-type
22136 (opaque-prosody-configuration
22137 (prosody.cfg.lua "")))
22140 @c end of Prosody auto-generated documentation
22142 @subsubheading BitlBee Service
22144 @cindex IRC (Internet Relay Chat)
22145 @cindex IRC gateway
22146 @url{https://bitlbee.org,BitlBee} is a gateway that provides an IRC
22147 interface to a variety of messaging protocols such as XMPP.
22149 @defvr {Scheme Variable} bitlbee-service-type
22150 This is the service type for the @url{https://bitlbee.org,BitlBee} IRC
22151 gateway daemon. Its value is a @code{bitlbee-configuration} (see
22154 To have BitlBee listen on port 6667 on localhost, add this line to your
22158 (service bitlbee-service-type)
22162 @deftp {Data Type} bitlbee-configuration
22163 This is the configuration for BitlBee, with the following fields:
22166 @item @code{interface} (default: @code{"127.0.0.1"})
22167 @itemx @code{port} (default: @code{6667})
22168 Listen on the network interface corresponding to the IP address
22169 specified in @var{interface}, on @var{port}.
22171 When @var{interface} is @code{127.0.0.1}, only local clients can
22172 connect; when it is @code{0.0.0.0}, connections can come from any
22173 networking interface.
22175 @item @code{bitlbee} (default: @code{bitlbee})
22176 The BitlBee package to use.
22178 @item @code{plugins} (default: @code{'()})
22179 List of plugin packages to use---e.g., @code{bitlbee-discord}.
22181 @item @code{extra-settings} (default: @code{""})
22182 Configuration snippet added as-is to the BitlBee configuration file.
22186 @subsubheading Quassel Service
22188 @cindex IRC (Internet Relay Chat)
22189 @url{https://quassel-irc.org/,Quassel} is a distributed IRC client,
22190 meaning that one or more clients can attach to and detach from the
22193 @defvr {Scheme Variable} quassel-service-type
22194 This is the service type for the @url{https://quassel-irc.org/,Quassel}
22195 IRC backend daemon. Its value is a @code{quassel-configuration}
22199 @deftp {Data Type} quassel-configuration
22200 This is the configuration for Quassel, with the following fields:
22203 @item @code{quassel} (default: @code{quassel})
22204 The Quassel package to use.
22206 @item @code{interface} (default: @code{"::,0.0.0.0"})
22207 @item @code{port} (default: @code{4242})
22208 Listen on the network interface(s) corresponding to the IPv4 or IPv6
22209 interfaces specified in the comma delimited @var{interface}, on
22212 @item @code{loglevel} (default: @code{"Info"})
22213 The level of logging desired. Accepted values are Debug, Info, Warning
22218 @node Telephony Services
22219 @subsection Telephony Services
22221 @cindex Murmur (VoIP server)
22222 @cindex VoIP server
22223 This section describes how to set up and run a Murmur server. Murmur is
22224 the server of the @uref{https://mumble.info, Mumble} voice-over-IP
22227 @deftp {Data Type} murmur-configuration
22228 The service type for the Murmur server. An example configuration can
22232 (service murmur-service-type
22233 (murmur-configuration
22235 "Welcome to this Mumble server running on Guix!")
22236 (cert-required? #t) ;disallow text password logins
22237 (ssl-cert "/etc/letsencrypt/live/mumble.example.com/fullchain.pem")
22238 (ssl-key "/etc/letsencrypt/live/mumble.example.com/privkey.pem")))
22241 After reconfiguring your system, you can manually set the murmur @code{SuperUser}
22242 password with the command that is printed during the activation phase.
22244 It is recommended to register a normal Mumble user account
22245 and grant it admin or moderator rights.
22246 You can use the @code{mumble} client to
22247 login as new normal user, register yourself, and log out.
22248 For the next step login with the name @code{SuperUser} use
22249 the @code{SuperUser} password that you set previously,
22250 and grant your newly registered mumble user administrator or moderator
22251 rights and create some channels.
22253 Available @code{murmur-configuration} fields are:
22256 @item @code{package} (default: @code{mumble})
22257 Package that contains @code{bin/murmurd}.
22259 @item @code{user} (default: @code{"murmur"})
22260 User who will run the Murmur server.
22262 @item @code{group} (default: @code{"murmur"})
22263 Group of the user who will run the murmur server.
22265 @item @code{port} (default: @code{64738})
22266 Port on which the server will listen.
22268 @item @code{welcome-text} (default: @code{""})
22269 Welcome text sent to clients when they connect.
22271 @item @code{server-password} (default: @code{""})
22272 Password the clients have to enter in order to connect.
22274 @item @code{max-users} (default: @code{100})
22275 Maximum of users that can be connected to the server at once.
22277 @item @code{max-user-bandwidth} (default: @code{#f})
22278 Maximum voice traffic a user can send per second.
22280 @item @code{database-file} (default: @code{"/var/lib/murmur/db.sqlite"})
22281 File name of the sqlite database.
22282 The service's user will become the owner of the directory.
22284 @item @code{log-file} (default: @code{"/var/log/murmur/murmur.log"})
22285 File name of the log file.
22286 The service's user will become the owner of the directory.
22288 @item @code{autoban-attempts} (default: @code{10})
22289 Maximum number of logins a user can make in @code{autoban-timeframe}
22290 without getting auto banned for @code{autoban-time}.
22292 @item @code{autoban-timeframe} (default: @code{120})
22293 Timeframe for autoban in seconds.
22295 @item @code{autoban-time} (default: @code{300})
22296 Amount of time in seconds for which a client gets banned
22297 when violating the autoban limits.
22299 @item @code{opus-threshold} (default: @code{100})
22300 Percentage of clients that need to support opus
22301 before switching over to opus audio codec.
22303 @item @code{channel-nesting-limit} (default: @code{10})
22304 How deep channels can be nested at maximum.
22306 @item @code{channelname-regex} (default: @code{#f})
22307 A string in form of a Qt regular expression that channel names must conform to.
22309 @item @code{username-regex} (default: @code{#f})
22310 A string in form of a Qt regular expression that user names must conform to.
22312 @item @code{text-message-length} (default: @code{5000})
22313 Maximum size in bytes that a user can send in one text chat message.
22315 @item @code{image-message-length} (default: @code{(* 128 1024)})
22316 Maximum size in bytes that a user can send in one image message.
22318 @item @code{cert-required?} (default: @code{#f})
22319 If it is set to @code{#t} clients that use weak password authentication
22320 will not be accepted. Users must have completed the certificate wizard to join.
22322 @item @code{remember-channel?} (default: @code{#f})
22323 Should murmur remember the last channel each user was in when they disconnected
22324 and put them into the remembered channel when they rejoin.
22326 @item @code{allow-html?} (default: @code{#f})
22327 Should html be allowed in text messages, user comments, and channel descriptions.
22329 @item @code{allow-ping?} (default: @code{#f})
22330 Setting to true exposes the current user count, the maximum user count, and
22331 the server's maximum bandwidth per client to unauthenticated users. In the
22332 Mumble client, this information is shown in the Connect dialog.
22334 Disabling this setting will prevent public listing of the server.
22336 @item @code{bonjour?} (default: @code{#f})
22337 Should the server advertise itself in the local network through the bonjour protocol.
22339 @item @code{send-version?} (default: @code{#f})
22340 Should the murmur server version be exposed in ping requests.
22342 @item @code{log-days} (default: @code{31})
22343 Murmur also stores logs in the database, which are accessible via RPC.
22344 The default is 31 days of months, but you can set this setting to 0 to keep logs forever,
22345 or -1 to disable logging to the database.
22347 @item @code{obfuscate-ips?} (default: @code{#t})
22348 Should logged ips be obfuscated to protect the privacy of users.
22350 @item @code{ssl-cert} (default: @code{#f})
22351 File name of the SSL/TLS certificate used for encrypted connections.
22354 (ssl-cert "/etc/letsencrypt/live/example.com/fullchain.pem")
22356 @item @code{ssl-key} (default: @code{#f})
22357 Filepath to the ssl private key used for encrypted connections.
22359 (ssl-key "/etc/letsencrypt/live/example.com/privkey.pem")
22362 @item @code{ssl-dh-params} (default: @code{#f})
22363 File name of a PEM-encoded file with Diffie-Hellman parameters
22364 for the SSL/TLS encryption. Alternatively you set it to
22365 @code{"@@ffdhe2048"}, @code{"@@ffdhe3072"}, @code{"@@ffdhe4096"}, @code{"@@ffdhe6144"}
22366 or @code{"@@ffdhe8192"} to use bundled parameters from RFC 7919.
22368 @item @code{ssl-ciphers} (default: @code{#f})
22369 The @code{ssl-ciphers} option chooses the cipher suites to make available for use
22372 This option is specified using
22373 @uref{https://www.openssl.org/docs/apps/ciphers.html#CIPHER-LIST-FORMAT,
22374 OpenSSL cipher list notation}.
22376 It is recommended that you try your cipher string using 'openssl ciphers <string>'
22377 before setting it here, to get a feel for which cipher suites you will get.
22378 After setting this option, it is recommend that you inspect your Murmur log
22379 to ensure that Murmur is using the cipher suites that you expected it to.
22381 Note: Changing this option may impact the backwards compatibility of your
22382 Murmur server, and can remove the ability for older Mumble clients to be able
22385 @item @code{public-registration} (default: @code{#f})
22386 Must be a @code{<murmur-public-registration-configuration>} record or @code{#f}.
22388 You can optionally register your server in the public server list that the
22389 @code{mumble} client shows on startup.
22390 You cannot register your server if you have set a @code{server-password},
22391 or set @code{allow-ping} to @code{#f}.
22393 It might take a few hours until it shows up in the public list.
22395 @item @code{file} (default: @code{#f})
22396 Optional alternative override for this configuration.
22400 @deftp {Data Type} murmur-public-registration-configuration
22401 Configuration for public registration of a murmur service.
22405 This is a display name for your server. Not to be confused with the hostname.
22407 @item @code{password}
22408 A password to identify your registration.
22409 Subsequent updates will need the same password. Don't lose your password.
22412 This should be a @code{http://} or @code{https://} link to your web
22415 @item @code{hostname} (default: @code{#f})
22416 By default your server will be listed by its IP address.
22417 If it is set your server will be linked by this host name instead.
22423 @node File-Sharing Services
22424 @subsection File-Sharing Services
22426 The @code{(gnu services file-sharing)} module provides services that
22427 assist with transferring files over peer-to-peer file-sharing networks.
22429 @subsubheading Transmission Daemon Service
22431 @uref{https://transmissionbt.com/, Transmission} is a flexible
22432 BitTorrent client that offers a variety of graphical and command-line
22433 interfaces. A @code{transmission-daemon-service-type} service provides
22434 Transmission's headless variant, @command{transmission-daemon}, as a
22435 system service, allowing users to share files via BitTorrent even when
22436 they are not logged in.
22438 @deffn {Scheme Variable} transmission-daemon-service-type
22439 The service type for the Transmission Daemon BitTorrent client. Its
22440 value must be a @code{transmission-daemon-configuration} object as in
22444 (service transmission-daemon-service-type
22445 (transmission-daemon-configuration
22446 ;; Restrict access to the RPC ("control") interface
22447 (rpc-authentication-required? #t)
22448 (rpc-username "transmission")
22450 (transmission-password-hash
22451 "transmission" ; desired password
22452 "uKd1uMs9")) ; arbitrary salt value
22454 ;; Accept requests from this and other hosts on the
22456 (rpc-whitelist-enabled? #t)
22457 (rpc-whitelist '("::1" "127.0.0.1" "192.168.0.*"))
22459 ;; Limit bandwidth use during work hours
22460 (alt-speed-down (* 1024 2)) ; 2 MB/s
22461 (alt-speed-up 512) ; 512 kB/s
22463 (alt-speed-time-enabled? #t)
22464 (alt-speed-time-day 'weekdays)
22465 (alt-speed-time-begin
22466 (+ (* 60 8) 30)) ; 8:30 am
22467 (alt-speed-time-end
22468 (+ (* 60 (+ 12 5)) 30)))) ; 5:30 pm
22472 Once the service is started, users can interact with the daemon through
22473 its Web interface (at @code{http://localhost:9091/}) or by using the
22474 @command{transmission-remote} command-line tool, available in the
22475 @code{transmission} package. (Emacs users may want to also consider the
22476 @code{emacs-transmission} package.) Both communicate with the daemon
22477 through its remote procedure call (RPC) interface, which by default is
22478 available to all users on the system; you may wish to change this by
22479 assigning values to the @code{rpc-authentication-required?},
22480 @code{rpc-username} and @code{rpc-password} settings, as shown in the
22481 example above and documented further below.
22483 The value for @code{rpc-password} must be a password hash of the type
22484 generated and used by Transmission clients. This can be copied verbatim
22485 from an existing @file{settings.json} file, if another Transmission
22486 client is already being used. Otherwise, the
22487 @code{transmission-password-hash} and @code{transmission-random-salt}
22488 procedures provided by this module can be used to obtain a suitable hash
22491 @deffn {Scheme Procedure} transmission-password-hash @var{password} @var{salt}
22492 Returns a string containing the result of hashing @var{password}
22493 together with @var{salt}, in the format recognized by Transmission
22494 clients for their @code{rpc-password} configuration setting.
22496 @var{salt} must be an eight-character string. The
22497 @code{transmission-random-salt} procedure can be used to generate a
22498 suitable salt value at random.
22501 @deffn {Scheme Procedure} transmission-random-salt
22502 Returns a string containing a random, eight-character salt value of the
22503 type generated and used by Transmission clients, suitable for passing to
22504 the @code{transmission-password-hash} procedure.
22507 These procedures are accessible from within a Guile REPL started with
22508 the @command{guix repl} command (@pxref{Invoking guix repl}). This is
22509 useful for obtaining a random salt value to provide as the second
22510 parameter to `transmission-password-hash`, as in this example session:
22514 scheme@@(guix-user)> ,use (gnu services file-sharing)
22515 scheme@@(guix-user)> (transmission-random-salt)
22519 Alternatively, a complete password hash can generated in a single step:
22522 scheme@@(guix-user)> (transmission-password-hash "transmission"
22523 (transmission-random-salt))
22524 $2 = "@{c8bbc6d1740cd8dc819a6e25563b67812c1c19c9VtFPfdsX"
22527 The resulting string can be used as-is for the value of
22528 @code{rpc-password}, allowing the password to be kept hidden even in the
22529 operating-system configuration.
22531 Torrent files downloaded by the daemon are directly accessible only to
22532 users in the ``transmission'' user group, who receive read-only access
22533 to the directory specified by the @code{download-dir} configuration
22534 setting (and also the directory specified by @code{incomplete-dir}, if
22535 @code{incomplete-dir-enabled?} is @code{#t}). Downloaded files can be
22536 moved to another directory or deleted altogether using
22537 @command{transmission-remote} with its @code{--move} and
22538 @code{--remove-and-delete} options.
22540 If the @code{watch-dir-enabled?} setting is set to @code{#t}, users in
22541 the ``transmission'' group are able also to place @file{.torrent} files
22542 in the directory specified by @code{watch-dir} to have the corresponding
22543 torrents added by the daemon. (The @code{trash-original-torrent-files?}
22544 setting controls whether the daemon deletes these files after processing
22547 Some of the daemon's configuration settings can be changed temporarily
22548 by @command{transmission-remote} and similar tools. To undo these
22549 changes, use the service's @code{reload} action to have the daemon
22550 reload its settings from disk:
22553 # herd reload transmission-daemon
22556 The full set of available configuration settings is defined by the
22557 @code{transmission-daemon-configuration} data type.
22559 @deftp {Data Type} transmission-daemon-configuration
22560 The data type representing configuration settings for Transmission
22561 Daemon. These correspond directly to the settings recognized by
22562 Transmission clients in their @file{settings.json} file.
22565 @c The following documentation was initially generated by
22566 @c (generate-transmission-daemon-documentation) in (gnu services
22567 @c file-sharing). Manually maintained documentation is better, so we
22568 @c shouldn't hesitate to edit below as needed. However if the change
22569 @c you want to make to this documentation can be done in an automated
22570 @c way, it's probably easier to change (generate-documentation) than to
22571 @c make it below and have to deal with the churn as Transmission Daemon
22574 @c %start of fragment
22576 Available @code{transmission-daemon-configuration} fields are:
22578 @deftypevr {@code{transmission-daemon-configuration} parameter} package transmission
22579 The Transmission package to use.
22583 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer stop-wait-period
22584 The period, in seconds, to wait when stopping the service for
22585 @command{transmission-daemon} to exit before killing its process. This
22586 allows the daemon time to complete its housekeeping and send a final
22587 update to trackers as it shuts down. On slow hosts, or hosts with a
22588 slow network connection, this value may need to be increased.
22590 Defaults to @samp{10}.
22594 @deftypevr {@code{transmission-daemon-configuration} parameter} string download-dir
22595 The directory to which torrent files are downloaded.
22597 Defaults to @samp{"/var/lib/transmission-daemon/downloads"}.
22601 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean incomplete-dir-enabled?
22602 If @code{#t}, files will be held in @code{incomplete-dir} while their
22603 torrent is being downloaded, then moved to @code{download-dir} once the
22604 torrent is complete. Otherwise, files for all torrents (including those
22605 still being downloaded) will be placed in @code{download-dir}.
22607 Defaults to @samp{#f}.
22611 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string incomplete-dir
22612 The directory in which files from incompletely downloaded torrents will
22613 be held when @code{incomplete-dir-enabled?} is @code{#t}.
22615 Defaults to @samp{disabled}.
22619 @deftypevr {@code{transmission-daemon-configuration} parameter} umask umask
22620 The file mode creation mask used for downloaded files. (See the
22621 @command{umask} man page for more information.)
22623 Defaults to @samp{18}.
22627 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rename-partial-files?
22628 When @code{#t}, ``.part'' is appended to the name of partially
22631 Defaults to @samp{#t}.
22635 @deftypevr {@code{transmission-daemon-configuration} parameter} preallocation-mode preallocation
22636 The mode by which space should be preallocated for downloaded files, one
22637 of @code{none}, @code{fast} (or @code{sparse}) and @code{full}.
22638 Specifying @code{full} will minimize disk fragmentation at a cost to
22639 file-creation speed.
22641 Defaults to @samp{fast}.
22645 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean watch-dir-enabled?
22646 If @code{#t}, the directory specified by @code{watch-dir} will be
22647 watched for new @file{.torrent} files and the torrents they describe
22648 added automatically (and the original files removed, if
22649 @code{trash-original-torrent-files?} is @code{#t}).
22651 Defaults to @samp{#f}.
22655 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string watch-dir
22656 The directory to be watched for @file{.torrent} files indicating new
22657 torrents to be added, when @code{watch-dir-enabled} is @code{#t}.
22659 Defaults to @samp{disabled}.
22663 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean trash-original-torrent-files?
22664 When @code{#t}, @file{.torrent} files will be deleted from the watch
22665 directory once their torrent has been added (see
22666 @code{watch-directory-enabled?}).
22668 Defaults to @samp{#f}.
22672 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-down-enabled?
22673 When @code{#t}, the daemon's download speed will be limited to the rate
22674 specified by @code{speed-limit-down}.
22676 Defaults to @samp{#f}.
22680 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-down
22681 The default global-maximum download speed, in kilobytes per second.
22683 Defaults to @samp{100}.
22687 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean speed-limit-up-enabled?
22688 When @code{#t}, the daemon's upload speed will be limited to the rate
22689 specified by @code{speed-limit-up}.
22691 Defaults to @samp{#f}.
22695 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer speed-limit-up
22696 The default global-maximum upload speed, in kilobytes per second.
22698 Defaults to @samp{100}.
22702 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-enabled?
22703 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
22704 @code{alt-speed-up} are used (in place of @code{speed-limit-down} and
22705 @code{speed-limit-up}, if they are enabled) to constrain the daemon's
22706 bandwidth usage. This can be scheduled to occur automatically at
22707 certain times during the week; see @code{alt-speed-time-enabled?}.
22709 Defaults to @samp{#f}.
22713 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-down
22714 The alternate global-maximum download speed, in kilobytes per second.
22716 Defaults to @samp{50}.
22720 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-up
22721 The alternate global-maximum upload speed, in kilobytes per second.
22723 Defaults to @samp{50}.
22727 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean alt-speed-time-enabled?
22728 When @code{#t}, the alternate speed limits @code{alt-speed-down} and
22729 @code{alt-speed-up} will be enabled automatically during the periods
22730 specified by @code{alt-speed-time-day}, @code{alt-speed-time-begin} and
22731 @code{alt-time-speed-end}.
22733 Defaults to @samp{#f}.
22737 @deftypevr {@code{transmission-daemon-configuration} parameter} day-list alt-speed-time-day
22738 The days of the week on which the alternate-speed schedule should be
22739 used, specified either as a list of days (@code{sunday}, @code{monday},
22740 and so on) or using one of the symbols @code{weekdays}, @code{weekends}
22743 Defaults to @samp{all}.
22747 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-begin
22748 The time of day at which to enable the alternate speed limits, expressed
22749 as a number of minutes since midnight.
22751 Defaults to @samp{540}.
22755 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer alt-speed-time-end
22756 The time of day at which to disable the alternate speed limits,
22757 expressed as a number of minutes since midnight.
22759 Defaults to @samp{1020}.
22763 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv4
22764 The IP address at which to listen for peer connections, or ``0.0.0.0''
22765 to listen at all available IP addresses.
22767 Defaults to @samp{"0.0.0.0"}.
22771 @deftypevr {@code{transmission-daemon-configuration} parameter} string bind-address-ipv6
22772 The IPv6 address at which to listen for peer connections, or ``::'' to
22773 listen at all available IPv6 addresses.
22775 Defaults to @samp{"::"}.
22779 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean peer-port-random-on-start?
22780 If @code{#t}, when the daemon starts it will select a port at random on
22781 which to listen for peer connections, from the range specified
22782 (inclusively) by @code{peer-port-random-low} and
22783 @code{peer-port-random-high}. Otherwise, it listens on the port
22784 specified by @code{peer-port}.
22786 Defaults to @samp{#f}.
22790 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-low
22791 The lowest selectable port number when @code{peer-port-random-on-start?}
22794 Defaults to @samp{49152}.
22798 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port-random-high
22799 The highest selectable port number when @code{peer-port-random-on-start}
22802 Defaults to @samp{65535}.
22806 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number peer-port
22807 The port on which to listen for peer connections when
22808 @code{peer-port-random-on-start?} is @code{#f}.
22810 Defaults to @samp{51413}.
22814 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean port-forwarding-enabled?
22815 If @code{#t}, the daemon will attempt to configure port-forwarding on an
22816 upstream gateway automatically using @acronym{UPnP} and
22819 Defaults to @samp{#t}.
22823 @deftypevr {@code{transmission-daemon-configuration} parameter} encryption-mode encryption
22824 The encryption preference for peer connections, one of
22825 @code{prefer-unencrypted-connections},
22826 @code{prefer-encrypted-connections} or
22827 @code{require-encrypted-connections}.
22829 Defaults to @samp{prefer-encrypted-connections}.
22833 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string peer-congestion-algorithm
22834 The TCP congestion-control algorithm to use for peer connections,
22835 specified using a string recognized by the operating system in calls to
22836 @code{setsockopt} (or set to @code{disabled}, in which case the
22837 operating-system default is used).
22839 Note that on GNU/Linux systems, the kernel must be configured to allow
22840 processes to use a congestion-control algorithm not in the default set;
22841 otherwise, it will deny these requests with ``Operation not permitted''.
22842 To see which algorithms are available on your system and which are
22843 currently permitted for use, look at the contents of the files
22844 @file{tcp_available_congestion_control} and
22845 @file{tcp_allowed_congestion_control} in the @file{/proc/sys/net/ipv4}
22848 As an example, to have Transmission Daemon use
22849 @uref{http://www-ece.rice.edu/networks/TCP-LP/,the TCP Low Priority
22850 congestion-control algorithm}, you'll need to modify your kernel
22851 configuration to build in support for the algorithm, then update your
22852 operating-system configuration to allow its use by adding a
22853 @code{sysctl-service-type} service (or updating the existing one's
22854 configuration) with lines like the following:
22857 (service sysctl-service-type
22858 (sysctl-configuration
22860 ("net.ipv4.tcp_allowed_congestion_control" .
22861 "reno cubic lp"))))
22864 The Transmission Daemon configuration can then be updated with
22867 (peer-congestion-algorithm "lp")
22870 and the system reconfigured to have the changes take effect.
22872 Defaults to @samp{disabled}.
22876 @deftypevr {@code{transmission-daemon-configuration} parameter} tcp-type-of-service peer-socket-tos
22877 The type of service to request in outgoing @acronym{TCP} packets, one of
22878 @code{default}, @code{low-cost}, @code{throughput}, @code{low-delay} and
22879 @code{reliability}.
22881 Defaults to @samp{default}.
22885 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-global
22886 The global limit on the number of connected peers.
22888 Defaults to @samp{200}.
22892 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-limit-per-torrent
22893 The per-torrent limit on the number of connected peers.
22895 Defaults to @samp{50}.
22899 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer upload-slots-per-torrent
22900 The maximum number of peers to which the daemon will upload data
22901 simultaneously for each torrent.
22903 Defaults to @samp{14}.
22907 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer peer-id-ttl-hours
22908 The maximum lifespan, in hours, of the peer ID associated with each
22909 public torrent before it is regenerated.
22911 Defaults to @samp{6}.
22915 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean blocklist-enabled?
22916 When @code{#t}, the daemon will ignore peers mentioned in the blocklist
22917 it has most recently downloaded from @code{blocklist-url}.
22919 Defaults to @samp{#f}.
22923 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string blocklist-url
22924 The URL of a peer blocklist (in @acronym{P2P}-plaintext or eMule
22925 @file{.dat} format) to be periodically downloaded and applied when
22926 @code{blocklist-enabled?} is @code{#t}.
22928 Defaults to @samp{disabled}.
22932 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean download-queue-enabled?
22933 If @code{#t}, the daemon will be limited to downloading at most
22934 @code{download-queue-size} non-stalled torrents simultaneously.
22936 Defaults to @samp{#t}.
22940 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer download-queue-size
22941 The size of the daemon's download queue, which limits the number of
22942 non-stalled torrents it will download at any one time when
22943 @code{download-queue-enabled?} is @code{#t}.
22945 Defaults to @samp{5}.
22949 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean seed-queue-enabled?
22950 If @code{#t}, the daemon will be limited to seeding at most
22951 @code{seed-queue-size} non-stalled torrents simultaneously.
22953 Defaults to @samp{#f}.
22957 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer seed-queue-size
22958 The size of the daemon's seed queue, which limits the number of
22959 non-stalled torrents it will seed at any one time when
22960 @code{seed-queue-enabled?} is @code{#t}.
22962 Defaults to @samp{10}.
22966 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean queue-stalled-enabled?
22967 When @code{#t}, the daemon will consider torrents for which it has not
22968 shared data in the past @code{queue-stalled-minutes} minutes to be
22969 stalled and not count them against its @code{download-queue-size} and
22970 @code{seed-queue-size} limits.
22972 Defaults to @samp{#t}.
22976 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer queue-stalled-minutes
22977 The maximum period, in minutes, a torrent may be idle before it is
22978 considered to be stalled, when @code{queue-stalled-enabled?} is
22981 Defaults to @samp{30}.
22985 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean ratio-limit-enabled?
22986 When @code{#t}, a torrent being seeded will automatically be paused once
22987 it reaches the ratio specified by @code{ratio-limit}.
22989 Defaults to @samp{#f}.
22993 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-rational ratio-limit
22994 The ratio at which a torrent being seeded will be paused, when
22995 @code{ratio-limit-enabled?} is @code{#t}.
22997 Defaults to @samp{2.0}.
23001 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean idle-seeding-limit-enabled?
23002 When @code{#t}, a torrent being seeded will automatically be paused once
23003 it has been idle for @code{idle-seeding-limit} minutes.
23005 Defaults to @samp{#f}.
23009 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer idle-seeding-limit
23010 The maximum period, in minutes, a torrent being seeded may be idle
23011 before it is paused, when @code{idle-seeding-limit-enabled?} is
23014 Defaults to @samp{30}.
23018 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean dht-enabled?
23019 Enable @uref{http://bittorrent.org/beps/bep_0005.html,the distributed
23020 hash table (@acronym{DHT}) protocol}, which supports the use of
23021 trackerless torrents.
23023 Defaults to @samp{#t}.
23027 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean lpd-enabled?
23028 Enable @uref{https://en.wikipedia.org/wiki/Local_Peer_Discovery,local
23029 peer discovery} (@acronym{LPD}), which allows the discovery of peers on
23030 the local network and may reduce the amount of data sent over the public
23033 Defaults to @samp{#f}.
23037 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean pex-enabled?
23038 Enable @uref{https://en.wikipedia.org/wiki/Peer_exchange,peer exchange}
23039 (@acronym{PEX}), which reduces the daemon's reliance on external
23040 trackers and may improve its performance.
23042 Defaults to @samp{#t}.
23046 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean utp-enabled?
23047 Enable @uref{http://bittorrent.org/beps/bep_0029.html,the micro
23048 transport protocol} (@acronym{uTP}), which aims to reduce the impact of
23049 BitTorrent traffic on other users of the local network while maintaining
23050 full utilization of the available bandwidth.
23052 Defaults to @samp{#t}.
23056 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-enabled?
23057 If @code{#t}, enable the remote procedure call (@acronym{RPC})
23058 interface, which allows remote control of the daemon via its Web
23059 interface, the @command{transmission-remote} command-line client, and
23062 Defaults to @samp{#t}.
23066 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-bind-address
23067 The IP address at which to listen for @acronym{RPC} connections, or
23068 ``0.0.0.0'' to listen at all available IP addresses.
23070 Defaults to @samp{"0.0.0.0"}.
23074 @deftypevr {@code{transmission-daemon-configuration} parameter} port-number rpc-port
23075 The port on which to listen for @acronym{RPC} connections.
23077 Defaults to @samp{9091}.
23081 @deftypevr {@code{transmission-daemon-configuration} parameter} string rpc-url
23082 The path prefix to use in the @acronym{RPC}-endpoint @acronym{URL}.
23084 Defaults to @samp{"/transmission/"}.
23088 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-authentication-required?
23089 When @code{#t}, clients must authenticate (see @code{rpc-username} and
23090 @code{rpc-password}) when using the @acronym{RPC} interface. Note this
23091 has the side effect of disabling host-name whitelisting (see
23092 @code{rpc-host-whitelist-enabled?}.
23094 Defaults to @samp{#f}.
23098 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-string rpc-username
23099 The username required by clients to access the @acronym{RPC} interface
23100 when @code{rpc-authentication-required?} is @code{#t}.
23102 Defaults to @samp{disabled}.
23106 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-transmission-password-hash rpc-password
23107 The password required by clients to access the @acronym{RPC} interface
23108 when @code{rpc-authentication-required?} is @code{#t}. This must be
23109 specified using a password hash in the format recognized by Transmission
23110 clients, either copied from an existing @file{settings.json} file or
23111 generated using the @code{transmission-password-hash} procedure.
23113 Defaults to @samp{disabled}.
23117 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-whitelist-enabled?
23118 When @code{#t}, @acronym{RPC} requests will be accepted only when they
23119 originate from an address specified in @code{rpc-whitelist}.
23121 Defaults to @samp{#t}.
23125 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-whitelist
23126 The list of IP and IPv6 addresses from which @acronym{RPC} requests will
23127 be accepted when @code{rpc-whitelist-enabled?} is @code{#t}. Wildcards
23128 may be specified using @samp{*}.
23130 Defaults to @samp{("127.0.0.1" "::1")}.
23134 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean rpc-host-whitelist-enabled?
23135 When @code{#t}, @acronym{RPC} requests will be accepted only when they
23136 are addressed to a host named in @code{rpc-host-whitelist}. Note that
23137 requests to ``localhost'' or ``localhost.'', or to a numeric address,
23138 are always accepted regardless of these settings.
23140 Note also this functionality is disabled when
23141 @code{rpc-authentication-required?} is @code{#t}.
23143 Defaults to @samp{#t}.
23147 @deftypevr {@code{transmission-daemon-configuration} parameter} string-list rpc-host-whitelist
23148 The list of host names recognized by the @acronym{RPC} server when
23149 @code{rpc-host-whitelist-enabled?} is @code{#t}.
23151 Defaults to @samp{()}.
23155 @deftypevr {@code{transmission-daemon-configuration} parameter} message-level message-level
23156 The minimum severity level of messages to be logged (to
23157 @file{/var/log/transmission.log}) by the daemon, one of @code{none} (no
23158 logging), @code{error}, @code{info} and @code{debug}.
23160 Defaults to @samp{info}.
23164 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean start-added-torrents?
23165 When @code{#t}, torrents are started as soon as they are added;
23166 otherwise, they are added in ``paused'' state.
23168 Defaults to @samp{#t}.
23172 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean script-torrent-done-enabled?
23173 When @code{#t}, the script specified by
23174 @code{script-torrent-done-filename} will be invoked each time a torrent
23177 Defaults to @samp{#f}.
23181 @deftypevr {@code{transmission-daemon-configuration} parameter} maybe-file-object script-torrent-done-filename
23182 A file name or file-like object specifying a script to run each time a
23183 torrent completes, when @code{script-torrent-done-enabled?} is
23186 Defaults to @samp{disabled}.
23190 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean scrape-paused-torrents-enabled?
23191 When @code{#t}, the daemon will scrape trackers for a torrent even when
23192 the torrent is paused.
23194 Defaults to @samp{#t}.
23198 @deftypevr {@code{transmission-daemon-configuration} parameter} non-negative-integer cache-size-mb
23199 The amount of memory, in megabytes, to allocate for the daemon's
23200 in-memory cache. A larger value may increase performance by reducing
23201 the frequency of disk I/O.
23203 Defaults to @samp{4}.
23207 @deftypevr {@code{transmission-daemon-configuration} parameter} boolean prefetch-enabled?
23208 When @code{#t}, the daemon will try to improve I/O performance by
23209 hinting to the operating system which data is likely to be read next
23210 from disk to satisfy requests from peers.
23212 Defaults to @samp{#t}.
23217 @c %end of fragment
23221 @node Monitoring Services
23222 @subsection Monitoring Services
23224 @subsubheading Tailon Service
23226 @uref{https://tailon.readthedocs.io/, Tailon} is a web application for
23227 viewing and searching log files.
23229 The following example will configure the service with default values.
23230 By default, Tailon can be accessed on port 8080 (@code{http://localhost:8080}).
23233 (service tailon-service-type)
23236 The following example customises more of the Tailon configuration,
23237 adding @command{sed} to the list of allowed commands.
23240 (service tailon-service-type
23241 (tailon-configuration
23243 (tailon-configuration-file
23244 (allowed-commands '("tail" "grep" "awk" "sed"))))))
23248 @deftp {Data Type} tailon-configuration
23249 Data type representing the configuration of Tailon.
23250 This type has the following parameters:
23253 @item @code{config-file} (default: @code{(tailon-configuration-file)})
23254 The configuration file to use for Tailon. This can be set to a
23255 @dfn{tailon-configuration-file} record value, or any gexp
23256 (@pxref{G-Expressions}).
23258 For example, to instead use a local file, the @code{local-file} function
23262 (service tailon-service-type
23263 (tailon-configuration
23264 (config-file (local-file "./my-tailon.conf"))))
23267 @item @code{package} (default: @code{tailon})
23268 The tailon package to use.
23273 @deftp {Data Type} tailon-configuration-file
23274 Data type representing the configuration options for Tailon.
23275 This type has the following parameters:
23278 @item @code{files} (default: @code{(list "/var/log")})
23279 List of files to display. The list can include strings for a single file
23280 or directory, or a list, where the first item is the name of a
23281 subsection, and the remaining items are the files or directories in that
23284 @item @code{bind} (default: @code{"localhost:8080"})
23285 Address and port to which Tailon should bind on.
23287 @item @code{relative-root} (default: @code{#f})
23288 URL path to use for Tailon, set to @code{#f} to not use a path.
23290 @item @code{allow-transfers?} (default: @code{#t})
23291 Allow downloading the log files in the web interface.
23293 @item @code{follow-names?} (default: @code{#t})
23294 Allow tailing of not-yet existent files.
23296 @item @code{tail-lines} (default: @code{200})
23297 Number of lines to read initially from each file.
23299 @item @code{allowed-commands} (default: @code{(list "tail" "grep" "awk")})
23300 Commands to allow running. By default, @code{sed} is disabled.
23302 @item @code{debug?} (default: @code{#f})
23303 Set @code{debug?} to @code{#t} to show debug messages.
23305 @item @code{wrap-lines} (default: @code{#t})
23306 Initial line wrapping state in the web interface. Set to @code{#t} to
23307 initially wrap lines (the default), or to @code{#f} to initially not
23310 @item @code{http-auth} (default: @code{#f})
23311 HTTP authentication type to use. Set to @code{#f} to disable
23312 authentication (the default). Supported values are @code{"digest"} or
23315 @item @code{users} (default: @code{#f})
23316 If HTTP authentication is enabled (see @code{http-auth}), access will be
23317 restricted to the credentials provided here. To configure users, use a
23318 list of pairs, where the first element of the pair is the username, and
23319 the 2nd element of the pair is the password.
23322 (tailon-configuration-file
23323 (http-auth "basic")
23324 (users '(("user1" . "password1")
23325 ("user2" . "password2"))))
23332 @subsubheading Darkstat Service
23334 Darkstat is a packet sniffer that captures network traffic, calculates
23335 statistics about usage, and serves reports over HTTP.
23337 @defvar {Scheme Variable} darkstat-service-type
23338 This is the service type for the
23339 @uref{https://unix4lyfe.org/darkstat/, darkstat}
23340 service, its value must be a @code{darkstat-configuration} record as in
23344 (service darkstat-service-type
23345 (darkstat-configuration
23346 (interface "eno1")))
23350 @deftp {Data Type} darkstat-configuration
23351 Data type representing the configuration of @command{darkstat}.
23354 @item @code{package} (default: @code{darkstat})
23355 The darkstat package to use.
23357 @item @code{interface}
23358 Capture traffic on the specified network interface.
23360 @item @code{port} (default: @code{"667"})
23361 Bind the web interface to the specified port.
23363 @item @code{bind-address} (default: @code{"127.0.0.1"})
23364 Bind the web interface to the specified address.
23366 @item @code{base} (default: @code{"/"})
23367 Specify the path of the base URL@. This can be useful if
23368 @command{darkstat} is accessed via a reverse proxy.
23373 @subsubheading Prometheus Node Exporter Service
23375 @cindex prometheus-node-exporter
23376 The Prometheus ``node exporter'' makes hardware and operating system statistics
23377 provided by the Linux kernel available for the Prometheus monitoring system.
23378 This service should be deployed on all physical nodes and virtual machines,
23379 where monitoring these statistics is desirable.
23381 @defvar {Scheme variable} prometheus-node-exporter-service-type
23382 This is the service type for the
23383 @uref{https://github.com/prometheus/node_exporter/, prometheus-node-exporter}
23384 service, its value must be a @code{prometheus-node-exporter-configuration}.
23387 (service prometheus-node-exporter-service-type)
23391 @deftp {Data Type} prometheus-node-exporter-configuration
23392 Data type representing the configuration of @command{node_exporter}.
23395 @item @code{package} (default: @code{go-github-com-prometheus-node-exporter})
23396 The prometheus-node-exporter package to use.
23398 @item @code{web-listen-address} (default: @code{":9100"})
23399 Bind the web interface to the specified address.
23401 @item @code{textfile-directory} (default: @code{"/var/lib/prometheus/node-exporter"})
23402 This directory can be used to export metrics specific to this machine.
23403 Files containing metrics in the text format, with the filename ending in
23404 @code{.prom} should be placed in this directory.
23406 @item @code{extra-options} (default: @code{'()})
23407 Extra options to pass to the Prometheus node exporter.
23412 @subsubheading Zabbix server
23413 @cindex zabbix zabbix-server
23414 Zabbix provides monitoring metrics, among others network utilization, CPU load
23415 and disk space consumption:
23418 @item High performance, high capacity (able to monitor hundreds of thousands of devices).
23419 @item Auto-discovery of servers and network devices and interfaces.
23420 @item Low-level discovery, allows to automatically start monitoring new items, file systems or network interfaces among others.
23421 @item Distributed monitoring with centralized web administration.
23422 @item Native high performance agents.
23423 @item SLA, and ITIL KPI metrics on reporting.
23424 @item High-level (business) view of monitored resources through user-defined visual console screens and dashboards.
23425 @item Remote command execution through Zabbix proxies.
23428 @c %start of fragment
23430 Available @code{zabbix-server-configuration} fields are:
23432 @deftypevr {@code{zabbix-server-configuration} parameter} package zabbix-server
23433 The zabbix-server package.
23437 @deftypevr {@code{zabbix-server-configuration} parameter} string user
23438 User who will run the Zabbix server.
23440 Defaults to @samp{"zabbix"}.
23444 @deftypevr {@code{zabbix-server-configuration} parameter} group group
23445 Group who will run the Zabbix server.
23447 Defaults to @samp{"zabbix"}.
23451 @deftypevr {@code{zabbix-server-configuration} parameter} string db-host
23452 Database host name.
23454 Defaults to @samp{"127.0.0.1"}.
23458 @deftypevr {@code{zabbix-server-configuration} parameter} string db-name
23461 Defaults to @samp{"zabbix"}.
23465 @deftypevr {@code{zabbix-server-configuration} parameter} string db-user
23468 Defaults to @samp{"zabbix"}.
23472 @deftypevr {@code{zabbix-server-configuration} parameter} string db-password
23473 Database password. Please, use @code{include-files} with
23474 @code{DBPassword=SECRET} inside a specified file instead.
23476 Defaults to @samp{""}.
23480 @deftypevr {@code{zabbix-server-configuration} parameter} number db-port
23483 Defaults to @samp{5432}.
23487 @deftypevr {@code{zabbix-server-configuration} parameter} string log-type
23488 Specifies where log messages are written to:
23492 @code{system} - syslog.
23495 @code{file} - file specified with @code{log-file} parameter.
23498 @code{console} - standard output.
23502 Defaults to @samp{""}.
23506 @deftypevr {@code{zabbix-server-configuration} parameter} string log-file
23507 Log file name for @code{log-type} @code{file} parameter.
23509 Defaults to @samp{"/var/log/zabbix/server.log"}.
23513 @deftypevr {@code{zabbix-server-configuration} parameter} string pid-file
23516 Defaults to @samp{"/var/run/zabbix/zabbix_server.pid"}.
23520 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-ca-location
23521 The location of certificate authority (CA) files for SSL server
23522 certificate verification.
23524 Defaults to @samp{"/etc/ssl/certs/ca-certificates.crt"}.
23528 @deftypevr {@code{zabbix-server-configuration} parameter} string ssl-cert-location
23529 Location of SSL client certificates.
23531 Defaults to @samp{"/etc/ssl/certs"}.
23535 @deftypevr {@code{zabbix-server-configuration} parameter} string extra-options
23536 Extra options will be appended to Zabbix server configuration file.
23538 Defaults to @samp{""}.
23542 @deftypevr {@code{zabbix-server-configuration} parameter} include-files include-files
23543 You may include individual files or all files in a directory in the
23544 configuration file.
23546 Defaults to @samp{()}.
23550 @c %end of fragment
23552 @subsubheading Zabbix agent
23553 @cindex zabbix zabbix-agent
23555 Zabbix agent gathers information for Zabbix server.
23557 @c %start of fragment
23559 Available @code{zabbix-agent-configuration} fields are:
23561 @deftypevr {@code{zabbix-agent-configuration} parameter} package zabbix-agent
23562 The zabbix-agent package.
23566 @deftypevr {@code{zabbix-agent-configuration} parameter} string user
23567 User who will run the Zabbix agent.
23569 Defaults to @samp{"zabbix"}.
23573 @deftypevr {@code{zabbix-agent-configuration} parameter} group group
23574 Group who will run the Zabbix agent.
23576 Defaults to @samp{"zabbix"}.
23580 @deftypevr {@code{zabbix-agent-configuration} parameter} string hostname
23581 Unique, case sensitive hostname which is required for active checks and
23582 must match hostname as configured on the server.
23584 Defaults to @samp{""}.
23588 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-type
23589 Specifies where log messages are written to:
23593 @code{system} - syslog.
23596 @code{file} - file specified with @code{log-file} parameter.
23599 @code{console} - standard output.
23603 Defaults to @samp{""}.
23607 @deftypevr {@code{zabbix-agent-configuration} parameter} string log-file
23608 Log file name for @code{log-type} @code{file} parameter.
23610 Defaults to @samp{"/var/log/zabbix/agent.log"}.
23614 @deftypevr {@code{zabbix-agent-configuration} parameter} string pid-file
23617 Defaults to @samp{"/var/run/zabbix/zabbix_agent.pid"}.
23621 @deftypevr {@code{zabbix-agent-configuration} parameter} list server
23622 List of IP addresses, optionally in CIDR notation, or hostnames of
23623 Zabbix servers and Zabbix proxies. Incoming connections will be
23624 accepted only from the hosts listed here.
23626 Defaults to @samp{("127.0.0.1")}.
23630 @deftypevr {@code{zabbix-agent-configuration} parameter} list server-active
23631 List of IP:port (or hostname:port) pairs of Zabbix servers and Zabbix
23632 proxies for active checks. If port is not specified, default port is
23633 used. If this parameter is not specified, active checks are disabled.
23635 Defaults to @samp{("127.0.0.1")}.
23639 @deftypevr {@code{zabbix-agent-configuration} parameter} string extra-options
23640 Extra options will be appended to Zabbix server configuration file.
23642 Defaults to @samp{""}.
23646 @deftypevr {@code{zabbix-agent-configuration} parameter} include-files include-files
23647 You may include individual files or all files in a directory in the
23648 configuration file.
23650 Defaults to @samp{()}.
23654 @c %end of fragment
23656 @subsubheading Zabbix front-end
23657 @cindex zabbix zabbix-front-end
23659 This service provides a WEB interface to Zabbix server.
23661 @c %start of fragment
23663 Available @code{zabbix-front-end-configuration} fields are:
23665 @deftypevr {@code{zabbix-front-end-configuration} parameter} nginx-server-configuration-list nginx
23666 NGINX configuration.
23670 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-host
23671 Database host name.
23673 Defaults to @samp{"localhost"}.
23677 @deftypevr {@code{zabbix-front-end-configuration} parameter} number db-port
23680 Defaults to @samp{5432}.
23684 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-name
23687 Defaults to @samp{"zabbix"}.
23691 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-user
23694 Defaults to @samp{"zabbix"}.
23698 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-password
23699 Database password. Please, use @code{db-secret-file} instead.
23701 Defaults to @samp{""}.
23705 @deftypevr {@code{zabbix-front-end-configuration} parameter} string db-secret-file
23706 Secret file containing the credentials for the Zabbix front-end. The value
23707 must be a local file name, not a G-expression. You are expected to create
23708 this file manually. Its contents will be copied into @file{zabbix.conf.php}
23709 as the value of @code{$DB['PASSWORD']}.
23711 Defaults to @samp{""}.
23715 @deftypevr {@code{zabbix-front-end-configuration} parameter} string zabbix-host
23716 Zabbix server hostname.
23718 Defaults to @samp{"localhost"}.
23722 @deftypevr {@code{zabbix-front-end-configuration} parameter} number zabbix-port
23723 Zabbix server port.
23725 Defaults to @samp{10051}.
23730 @c %end of fragment
23732 @node Kerberos Services
23733 @subsection Kerberos Services
23736 The @code{(gnu services kerberos)} module provides services relating to
23737 the authentication protocol @dfn{Kerberos}.
23739 @subsubheading Krb5 Service
23741 Programs using a Kerberos client library normally
23742 expect a configuration file in @file{/etc/krb5.conf}.
23743 This service generates such a file from a definition provided in the
23744 operating system declaration.
23745 It does not cause any daemon to be started.
23747 No ``keytab'' files are provided by this service---you must explicitly create them.
23748 This service is known to work with the MIT client library, @code{mit-krb5}.
23749 Other implementations have not been tested.
23751 @defvr {Scheme Variable} krb5-service-type
23752 A service type for Kerberos 5 clients.
23756 Here is an example of its use:
23758 (service krb5-service-type
23759 (krb5-configuration
23760 (default-realm "EXAMPLE.COM")
23761 (allow-weak-crypto? #t)
23764 (name "EXAMPLE.COM")
23765 (admin-server "groucho.example.com")
23766 (kdc "karl.example.com"))
23769 (admin-server "kerb-admin.argrx.edu")
23770 (kdc "keys.argrx.edu"))))))
23774 This example provides a Kerberos@tie{}5 client configuration which:
23776 @item Recognizes two realms, @i{viz:} ``EXAMPLE.COM'' and ``ARGRX.EDU'', both
23777 of which have distinct administration servers and key distribution centers;
23778 @item Will default to the realm ``EXAMPLE.COM'' if the realm is not explicitly
23779 specified by clients;
23780 @item Accepts services which only support encryption types known to be weak.
23783 The @code{krb5-realm} and @code{krb5-configuration} types have many fields.
23784 Only the most commonly used ones are described here.
23785 For a full list, and more detailed explanation of each, see the MIT
23786 @uref{https://web.mit.edu/kerberos/krb5-devel/doc/admin/conf_files/krb5_conf.html,,krb5.conf}
23790 @deftp {Data Type} krb5-realm
23791 @cindex realm, kerberos
23794 This field is a string identifying the name of the realm.
23795 A common convention is to use the fully qualified DNS name of your organization,
23796 converted to upper case.
23798 @item @code{admin-server}
23799 This field is a string identifying the host where the administration server is
23803 This field is a string identifying the key distribution center
23808 @deftp {Data Type} krb5-configuration
23811 @item @code{allow-weak-crypto?} (default: @code{#f})
23812 If this flag is @code{#t} then services which only offer encryption algorithms
23813 known to be weak will be accepted.
23815 @item @code{default-realm} (default: @code{#f})
23816 This field should be a string identifying the default Kerberos
23817 realm for the client.
23818 You should set this field to the name of your Kerberos realm.
23819 If this value is @code{#f}
23820 then a realm must be specified with every Kerberos principal when invoking programs
23821 such as @command{kinit}.
23823 @item @code{realms}
23824 This should be a non-empty list of @code{krb5-realm} objects, which clients may
23826 Normally, one of them will have a @code{name} field matching the @code{default-realm}
23832 @subsubheading PAM krb5 Service
23835 The @code{pam-krb5} service allows for login authentication and password
23836 management via Kerberos.
23837 You will need this service if you want PAM enabled applications to authenticate
23838 users using Kerberos.
23840 @defvr {Scheme Variable} pam-krb5-service-type
23841 A service type for the Kerberos 5 PAM module.
23844 @deftp {Data Type} pam-krb5-configuration
23845 Data type representing the configuration of the Kerberos 5 PAM module.
23846 This type has the following parameters:
23848 @item @code{pam-krb5} (default: @code{pam-krb5})
23849 The pam-krb5 package to use.
23851 @item @code{minimum-uid} (default: @code{1000})
23852 The smallest user ID for which Kerberos authentications should be attempted.
23853 Local accounts with lower values will silently fail to authenticate.
23858 @node LDAP Services
23859 @subsection LDAP Services
23861 @cindex nslcd, LDAP service
23863 The @code{(gnu services authentication)} module provides the
23864 @code{nslcd-service-type}, which can be used to authenticate against an LDAP
23865 server. In addition to configuring the service itself, you may want to add
23866 @code{ldap} as a name service to the Name Service Switch. @xref{Name Service
23867 Switch} for detailed information.
23869 Here is a simple operating system declaration with a default configuration of
23870 the @code{nslcd-service-type} and a Name Service Switch configuration that
23871 consults the @code{ldap} name service last:
23874 (use-service-modules authentication)
23875 (use-modules (gnu system nss))
23881 (service nslcd-service-type)
23882 (service dhcp-client-service-type)
23884 (name-service-switch
23885 (let ((services (list (name-service (name "db"))
23886 (name-service (name "files"))
23887 (name-service (name "ldap")))))
23888 (name-service-switch
23889 (inherit %mdns-host-lookup-nss)
23890 (password services)
23893 (netgroup services)
23894 (gshadow services)))))
23897 @c %start of generated documentation for nslcd-configuration
23899 Available @code{nslcd-configuration} fields are:
23901 @deftypevr {@code{nslcd-configuration} parameter} package nss-pam-ldapd
23902 The @code{nss-pam-ldapd} package to use.
23906 @deftypevr {@code{nslcd-configuration} parameter} maybe-number threads
23907 The number of threads to start that can handle requests and perform LDAP
23908 queries. Each thread opens a separate connection to the LDAP server.
23909 The default is to start 5 threads.
23911 Defaults to @samp{disabled}.
23915 @deftypevr {@code{nslcd-configuration} parameter} string uid
23916 This specifies the user id with which the daemon should be run.
23918 Defaults to @samp{"nslcd"}.
23922 @deftypevr {@code{nslcd-configuration} parameter} string gid
23923 This specifies the group id with which the daemon should be run.
23925 Defaults to @samp{"nslcd"}.
23929 @deftypevr {@code{nslcd-configuration} parameter} log-option log
23930 This option controls the way logging is done via a list containing
23931 SCHEME and LEVEL@. The SCHEME argument may either be the symbols
23932 @samp{none} or @samp{syslog}, or an absolute file name. The LEVEL
23933 argument is optional and specifies the log level. The log level may be
23934 one of the following symbols: @samp{crit}, @samp{error}, @samp{warning},
23935 @samp{notice}, @samp{info} or @samp{debug}. All messages with the
23936 specified log level or higher are logged.
23938 Defaults to @samp{("/var/log/nslcd" info)}.
23942 @deftypevr {@code{nslcd-configuration} parameter} list uri
23943 The list of LDAP server URIs. Normally, only the first server will be
23944 used with the following servers as fall-back.
23946 Defaults to @samp{("ldap://localhost:389/")}.
23950 @deftypevr {@code{nslcd-configuration} parameter} maybe-string ldap-version
23951 The version of the LDAP protocol to use. The default is to use the
23952 maximum version supported by the LDAP library.
23954 Defaults to @samp{disabled}.
23958 @deftypevr {@code{nslcd-configuration} parameter} maybe-string binddn
23959 Specifies the distinguished name with which to bind to the directory
23960 server for lookups. The default is to bind anonymously.
23962 Defaults to @samp{disabled}.
23966 @deftypevr {@code{nslcd-configuration} parameter} maybe-string bindpw
23967 Specifies the credentials with which to bind. This option is only
23968 applicable when used with binddn.
23970 Defaults to @samp{disabled}.
23974 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmoddn
23975 Specifies the distinguished name to use when the root user tries to
23976 modify a user's password using the PAM module.
23978 Defaults to @samp{disabled}.
23982 @deftypevr {@code{nslcd-configuration} parameter} maybe-string rootpwmodpw
23983 Specifies the credentials with which to bind if the root user tries to
23984 change a user's password. This option is only applicable when used with
23987 Defaults to @samp{disabled}.
23991 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-mech
23992 Specifies the SASL mechanism to be used when performing SASL
23995 Defaults to @samp{disabled}.
23999 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-realm
24000 Specifies the SASL realm to be used when performing SASL authentication.
24002 Defaults to @samp{disabled}.
24006 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authcid
24007 Specifies the authentication identity to be used when performing SASL
24010 Defaults to @samp{disabled}.
24014 @deftypevr {@code{nslcd-configuration} parameter} maybe-string sasl-authzid
24015 Specifies the authorization identity to be used when performing SASL
24018 Defaults to @samp{disabled}.
24022 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean sasl-canonicalize?
24023 Determines whether the LDAP server host name should be canonicalised. If
24024 this is enabled the LDAP library will do a reverse host name lookup. By
24025 default, it is left up to the LDAP library whether this check is
24028 Defaults to @samp{disabled}.
24032 @deftypevr {@code{nslcd-configuration} parameter} maybe-string krb5-ccname
24033 Set the name for the GSS-API Kerberos credentials cache.
24035 Defaults to @samp{disabled}.
24039 @deftypevr {@code{nslcd-configuration} parameter} string base
24040 The directory search base.
24042 Defaults to @samp{"dc=example,dc=com"}.
24046 @deftypevr {@code{nslcd-configuration} parameter} scope-option scope
24047 Specifies the search scope (subtree, onelevel, base or children). The
24048 default scope is subtree; base scope is almost never useful for name
24049 service lookups; children scope is not supported on all servers.
24051 Defaults to @samp{(subtree)}.
24055 @deftypevr {@code{nslcd-configuration} parameter} maybe-deref-option deref
24056 Specifies the policy for dereferencing aliases. The default policy is
24057 to never dereference aliases.
24059 Defaults to @samp{disabled}.
24063 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean referrals
24064 Specifies whether automatic referral chasing should be enabled. The
24065 default behaviour is to chase referrals.
24067 Defaults to @samp{disabled}.
24071 @deftypevr {@code{nslcd-configuration} parameter} list-of-map-entries maps
24072 This option allows for custom attributes to be looked up instead of the
24073 default RFC 2307 attributes. It is a list of maps, each consisting of
24074 the name of a map, the RFC 2307 attribute to match and the query
24075 expression for the attribute as it is available in the directory.
24077 Defaults to @samp{()}.
24081 @deftypevr {@code{nslcd-configuration} parameter} list-of-filter-entries filters
24082 A list of filters consisting of the name of a map to which the filter
24083 applies and an LDAP search filter expression.
24085 Defaults to @samp{()}.
24089 @deftypevr {@code{nslcd-configuration} parameter} maybe-number bind-timelimit
24090 Specifies the time limit in seconds to use when connecting to the
24091 directory server. The default value is 10 seconds.
24093 Defaults to @samp{disabled}.
24097 @deftypevr {@code{nslcd-configuration} parameter} maybe-number timelimit
24098 Specifies the time limit (in seconds) to wait for a response from the
24099 LDAP server. A value of zero, which is the default, is to wait
24100 indefinitely for searches to be completed.
24102 Defaults to @samp{disabled}.
24106 @deftypevr {@code{nslcd-configuration} parameter} maybe-number idle-timelimit
24107 Specifies the period if inactivity (in seconds) after which the con‐
24108 nection to the LDAP server will be closed. The default is not to time
24111 Defaults to @samp{disabled}.
24115 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-sleeptime
24116 Specifies the number of seconds to sleep when connecting to all LDAP
24117 servers fails. By default one second is waited between the first
24118 failure and the first retry.
24120 Defaults to @samp{disabled}.
24124 @deftypevr {@code{nslcd-configuration} parameter} maybe-number reconnect-retrytime
24125 Specifies the time after which the LDAP server is considered to be
24126 permanently unavailable. Once this time is reached retries will be done
24127 only once per this time period. The default value is 10 seconds.
24129 Defaults to @samp{disabled}.
24133 @deftypevr {@code{nslcd-configuration} parameter} maybe-ssl-option ssl
24134 Specifies whether to use SSL/TLS or not (the default is not to). If
24135 'start-tls is specified then StartTLS is used rather than raw LDAP over
24138 Defaults to @samp{disabled}.
24142 @deftypevr {@code{nslcd-configuration} parameter} maybe-tls-reqcert-option tls-reqcert
24143 Specifies what checks to perform on a server-supplied certificate. The
24144 meaning of the values is described in the ldap.conf(5) manual page.
24146 Defaults to @samp{disabled}.
24150 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertdir
24151 Specifies the directory containing X.509 certificates for peer authen‐
24152 tication. This parameter is ignored when using GnuTLS.
24154 Defaults to @samp{disabled}.
24158 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cacertfile
24159 Specifies the path to the X.509 certificate for peer authentication.
24161 Defaults to @samp{disabled}.
24165 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-randfile
24166 Specifies the path to an entropy source. This parameter is ignored when
24169 Defaults to @samp{disabled}.
24173 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-ciphers
24174 Specifies the ciphers to use for TLS as a string.
24176 Defaults to @samp{disabled}.
24180 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-cert
24181 Specifies the path to the file containing the local certificate for
24182 client TLS authentication.
24184 Defaults to @samp{disabled}.
24188 @deftypevr {@code{nslcd-configuration} parameter} maybe-string tls-key
24189 Specifies the path to the file containing the private key for client TLS
24192 Defaults to @samp{disabled}.
24196 @deftypevr {@code{nslcd-configuration} parameter} maybe-number pagesize
24197 Set this to a number greater than 0 to request paged results from the
24198 LDAP server in accordance with RFC2696. The default (0) is to not
24199 request paged results.
24201 Defaults to @samp{disabled}.
24205 @deftypevr {@code{nslcd-configuration} parameter} maybe-ignore-users-option nss-initgroups-ignoreusers
24206 This option prevents group membership lookups through LDAP for the
24207 specified users. Alternatively, the value 'all-local may be used. With
24208 that value nslcd builds a full list of non-LDAP users on startup.
24210 Defaults to @samp{disabled}.
24214 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-min-uid
24215 This option ensures that LDAP users with a numeric user id lower than
24216 the specified value are ignored.
24218 Defaults to @samp{disabled}.
24222 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-uid-offset
24223 This option specifies an offset that is added to all LDAP numeric user
24224 ids. This can be used to avoid user id collisions with local users.
24226 Defaults to @samp{disabled}.
24230 @deftypevr {@code{nslcd-configuration} parameter} maybe-number nss-gid-offset
24231 This option specifies an offset that is added to all LDAP numeric group
24232 ids. This can be used to avoid user id collisions with local groups.
24234 Defaults to @samp{disabled}.
24238 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-nested-groups
24239 If this option is set, the member attribute of a group may point to
24240 another group. Members of nested groups are also returned in the higher
24241 level group and parent groups are returned when finding groups for a
24242 specific user. The default is not to perform extra searches for nested
24245 Defaults to @samp{disabled}.
24249 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-getgrent-skipmembers
24250 If this option is set, the group member list is not retrieved when
24251 looking up groups. Lookups for finding which groups a user belongs to
24252 will remain functional so the user will likely still get the correct
24253 groups assigned on login.
24255 Defaults to @samp{disabled}.
24259 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean nss-disable-enumeration
24260 If this option is set, functions which cause all user/group entries to
24261 be loaded from the directory will not succeed in doing so. This can
24262 dramatically reduce LDAP server load in situations where there are a
24263 great number of users and/or groups. This option is not recommended for
24264 most configurations.
24266 Defaults to @samp{disabled}.
24270 @deftypevr {@code{nslcd-configuration} parameter} maybe-string validnames
24271 This option can be used to specify how user and group names are verified
24272 within the system. This pattern is used to check all user and group
24273 names that are requested and returned from LDAP.
24275 Defaults to @samp{disabled}.
24279 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean ignorecase
24280 This specifies whether or not to perform searches using case-insensitive
24281 matching. Enabling this could open up the system to authorization
24282 bypass vulnerabilities and introduce nscd cache poisoning
24283 vulnerabilities which allow denial of service.
24285 Defaults to @samp{disabled}.
24289 @deftypevr {@code{nslcd-configuration} parameter} maybe-boolean pam-authc-ppolicy
24290 This option specifies whether password policy controls are requested and
24291 handled from the LDAP server when performing user authentication.
24293 Defaults to @samp{disabled}.
24297 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authc-search
24298 By default nslcd performs an LDAP search with the user's credentials
24299 after BIND (authentication) to ensure that the BIND operation was
24300 successful. The default search is a simple check to see if the user's
24301 DN exists. A search filter can be specified that will be used instead.
24302 It should return at least one entry.
24304 Defaults to @samp{disabled}.
24308 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-authz-search
24309 This option allows flexible fine tuning of the authorisation check that
24310 should be performed. The search filter specified is executed and if any
24311 entries match, access is granted, otherwise access is denied.
24313 Defaults to @samp{disabled}.
24317 @deftypevr {@code{nslcd-configuration} parameter} maybe-string pam-password-prohibit-message
24318 If this option is set password modification using pam_ldap will be
24319 denied and the specified message will be presented to the user instead.
24320 The message can be used to direct the user to an alternative means of
24321 changing their password.
24323 Defaults to @samp{disabled}.
24327 @deftypevr {@code{nslcd-configuration} parameter} list pam-services
24328 List of pam service names for which LDAP authentication should suffice.
24330 Defaults to @samp{()}.
24334 @c %end of generated documentation for nslcd-configuration
24338 @subsection Web Services
24343 The @code{(gnu services web)} module provides the Apache HTTP Server,
24344 the nginx web server, and also a fastcgi wrapper daemon.
24346 @subsubheading Apache HTTP Server
24348 @deffn {Scheme Variable} httpd-service-type
24349 Service type for the @uref{https://httpd.apache.org/,Apache HTTP} server
24350 (@dfn{httpd}). The value for this service type is a
24351 @code{httpd-configuration} record.
24353 A simple example configuration is given below.
24356 (service httpd-service-type
24357 (httpd-configuration
24360 (server-name "www.example.com")
24361 (document-root "/srv/http/www.example.com")))))
24364 Other services can also extend the @code{httpd-service-type} to add to
24368 (simple-service 'www.example.com-server httpd-service-type
24372 (list (string-join '("ServerName www.example.com"
24373 "DocumentRoot /srv/http/www.example.com")
24378 The details for the @code{httpd-configuration}, @code{httpd-module},
24379 @code{httpd-config-file} and @code{httpd-virtualhost} record types are
24382 @deffn {Data Type} httpd-configuration
24383 This data type represents the configuration for the httpd service.
24386 @item @code{package} (default: @code{httpd})
24387 The httpd package to use.
24389 @item @code{pid-file} (default: @code{"/var/run/httpd"})
24390 The pid file used by the shepherd-service.
24392 @item @code{config} (default: @code{(httpd-config-file)})
24393 The configuration file to use with the httpd service. The default value
24394 is a @code{httpd-config-file} record, but this can also be a different
24395 G-expression that generates a file, for example a @code{plain-file}. A
24396 file outside of the store can also be specified through a string.
24401 @deffn {Data Type} httpd-module
24402 This data type represents a module for the httpd service.
24406 The name of the module.
24409 The file for the module. This can be relative to the httpd package being
24410 used, the absolute location of a file, or a G-expression for a file
24411 within the store, for example @code{(file-append mod-wsgi
24412 "/modules/mod_wsgi.so")}.
24417 @defvr {Scheme Variable} %default-httpd-modules
24418 A default list of @code{httpd-module} objects.
24421 @deffn {Data Type} httpd-config-file
24422 This data type represents a configuration file for the httpd service.
24425 @item @code{modules} (default: @code{%default-httpd-modules})
24426 The modules to load. Additional modules can be added here, or loaded by
24427 additional configuration.
24429 For example, in order to handle requests for PHP files, you can use Apache’s
24430 @code{mod_proxy_fcgi} module along with @code{php-fpm-service-type}:
24433 (service httpd-service-type
24434 (httpd-configuration
24439 (name "proxy_module")
24440 (file "modules/mod_proxy.so"))
24442 (name "proxy_fcgi_module")
24443 (file "modules/mod_proxy_fcgi.so"))
24444 %default-httpd-modules))
24445 (extra-config (list "\
24446 <FilesMatch \\.php$>
24447 SetHandler \"proxy:unix:/var/run/php-fpm.sock|fcgi://localhost/\"
24448 </FilesMatch>"))))))
24449 (service php-fpm-service-type
24450 (php-fpm-configuration
24451 (socket "/var/run/php-fpm.sock")
24452 (socket-group "httpd")))
24455 @item @code{server-root} (default: @code{httpd})
24456 The @code{ServerRoot} in the configuration file, defaults to the httpd
24457 package. Directives including @code{Include} and @code{LoadModule} are
24458 taken as relative to the server root.
24460 @item @code{server-name} (default: @code{#f})
24461 The @code{ServerName} in the configuration file, used to specify the
24462 request scheme, hostname and port that the server uses to identify
24465 This doesn't need to be set in the server config, and can be specified
24466 in virtual hosts. The default is @code{#f} to not specify a
24469 @item @code{document-root} (default: @code{"/srv/http"})
24470 The @code{DocumentRoot} from which files will be served.
24472 @item @code{listen} (default: @code{'("80")})
24473 The list of values for the @code{Listen} directives in the config
24474 file. The value should be a list of strings, when each string can
24475 specify the port number to listen on, and optionally the IP address and
24478 @item @code{pid-file} (default: @code{"/var/run/httpd"})
24479 The @code{PidFile} to use. This should match the @code{pid-file} set in
24480 the @code{httpd-configuration} so that the Shepherd service is
24481 configured correctly.
24483 @item @code{error-log} (default: @code{"/var/log/httpd/error_log"})
24484 The @code{ErrorLog} to which the server will log errors.
24486 @item @code{user} (default: @code{"httpd"})
24487 The @code{User} which the server will answer requests as.
24489 @item @code{group} (default: @code{"httpd"})
24490 The @code{Group} which the server will answer requests as.
24492 @item @code{extra-config} (default: @code{(list "TypesConfig etc/httpd/mime.types")})
24493 A flat list of strings and G-expressions which will be added to the end
24494 of the configuration file.
24496 Any values which the service is extended with will be appended to this
24502 @deffn {Data Type} httpd-virtualhost
24503 This data type represents a virtualhost configuration block for the httpd service.
24505 These should be added to the extra-config for the httpd-service.
24508 (simple-service 'www.example.com-server httpd-service-type
24512 (list (string-join '("ServerName www.example.com"
24513 "DocumentRoot /srv/http/www.example.com")
24518 @item @code{addresses-and-ports}
24519 The addresses and ports for the @code{VirtualHost} directive.
24521 @item @code{contents}
24522 The contents of the @code{VirtualHost} directive, this should be a list
24523 of strings and G-expressions.
24528 @subsubheading NGINX
24530 @deffn {Scheme Variable} nginx-service-type
24531 Service type for the @uref{https://nginx.org/,NGinx} web server. The
24532 value for this service type is a @code{<nginx-configuration>} record.
24534 A simple example configuration is given below.
24537 (service nginx-service-type
24538 (nginx-configuration
24540 (list (nginx-server-configuration
24541 (server-name '("www.example.com"))
24542 (root "/srv/http/www.example.com"))))))
24545 In addition to adding server blocks to the service configuration
24546 directly, this service can be extended by other services to add server
24547 blocks, as in this example:
24550 (simple-service 'my-extra-server nginx-service-type
24551 (list (nginx-server-configuration
24552 (root "/srv/http/extra-website")
24553 (try-files (list "$uri" "$uri/index.html")))))
24557 At startup, @command{nginx} has not yet read its configuration file, so
24558 it uses a default file to log error messages. If it fails to load its
24559 configuration file, that is where error messages are logged. After the
24560 configuration file is loaded, the default error log file changes as per
24561 configuration. In our case, startup error messages can be found in
24562 @file{/var/run/nginx/logs/error.log}, and after configuration in
24563 @file{/var/log/nginx/error.log}. The second location can be changed
24564 with the @var{log-directory} configuration option.
24566 @deffn {Data Type} nginx-configuration
24567 This data type represents the configuration for NGinx. Some
24568 configuration can be done through this and the other provided record
24569 types, or alternatively, a config file can be provided.
24572 @item @code{nginx} (default: @code{nginx})
24573 The nginx package to use.
24575 @item @code{log-directory} (default: @code{"/var/log/nginx"})
24576 The directory to which NGinx will write log files.
24578 @item @code{run-directory} (default: @code{"/var/run/nginx"})
24579 The directory in which NGinx will create a pid file, and write temporary
24582 @item @code{server-blocks} (default: @code{'()})
24583 A list of @dfn{server blocks} to create in the generated configuration
24584 file, the elements should be of type
24585 @code{<nginx-server-configuration>}.
24587 The following example would setup NGinx to serve @code{www.example.com}
24588 from the @code{/srv/http/www.example.com} directory, without using
24591 (service nginx-service-type
24592 (nginx-configuration
24594 (list (nginx-server-configuration
24595 (server-name '("www.example.com"))
24596 (root "/srv/http/www.example.com"))))))
24599 @item @code{upstream-blocks} (default: @code{'()})
24600 A list of @dfn{upstream blocks} to create in the generated configuration
24601 file, the elements should be of type
24602 @code{<nginx-upstream-configuration>}.
24604 Configuring upstreams through the @code{upstream-blocks} can be useful
24605 when combined with @code{locations} in the
24606 @code{<nginx-server-configuration>} records. The following example
24607 creates a server configuration with one location configuration, that
24608 will proxy requests to a upstream configuration, which will handle
24609 requests with two servers.
24614 (nginx-configuration
24616 (list (nginx-server-configuration
24617 (server-name '("www.example.com"))
24618 (root "/srv/http/www.example.com")
24621 (nginx-location-configuration
24623 (body '("proxy_pass http://server-proxy;"))))))))
24625 (list (nginx-upstream-configuration
24626 (name "server-proxy")
24627 (servers (list "server1.example.com"
24628 "server2.example.com")))))))
24631 @item @code{file} (default: @code{#f})
24632 If a configuration @var{file} is provided, this will be used, rather than
24633 generating a configuration file from the provided @code{log-directory},
24634 @code{run-directory}, @code{server-blocks} and @code{upstream-blocks}. For
24635 proper operation, these arguments should match what is in @var{file} to ensure
24636 that the directories are created when the service is activated.
24638 This can be useful if you have an existing configuration file, or it's
24639 not possible to do what is required through the other parts of the
24640 nginx-configuration record.
24642 @item @code{server-names-hash-bucket-size} (default: @code{#f})
24643 Bucket size for the server names hash tables, defaults to @code{#f} to
24644 use the size of the processors cache line.
24646 @item @code{server-names-hash-bucket-max-size} (default: @code{#f})
24647 Maximum bucket size for the server names hash tables.
24649 @item @code{modules} (default: @code{'()})
24650 List of nginx dynamic modules to load. This should be a list of file
24651 names of loadable modules, as in this example:
24656 (file-append nginx-accept-language-module "\
24657 /etc/nginx/modules/ngx_http_accept_language_module.so")
24658 (file-append nginx-lua-module "\
24659 /etc/nginx/modules/ngx_http_lua_module.so")))
24662 @item @code{lua-package-path} (default: @code{'()})
24663 List of nginx lua packages to load. This should be a list of package
24664 names of loadable lua modules, as in this example:
24667 (lua-package-path (list lua-resty-core
24674 @item @code{lua-package-cpath} (default: @code{'()})
24675 List of nginx lua C packages to load. This should be a list of package
24676 names of loadable lua C modules, as in this example:
24679 (lua-package-cpath (list lua-resty-signal))
24682 @item @code{global-directives} (default: @code{'((events . ()))})
24683 Association list of global directives for the top level of the nginx
24684 configuration. Values may themselves be association lists.
24688 `((worker_processes . 16)
24690 (events . ((worker_connections . 1024)))))
24693 @item @code{extra-content} (default: @code{""})
24694 Extra content for the @code{http} block. Should be string or a string
24695 valued G-expression.
24700 @deftp {Data Type} nginx-server-configuration
24701 Data type representing the configuration of an nginx server block.
24702 This type has the following parameters:
24705 @item @code{listen} (default: @code{'("80" "443 ssl")})
24706 Each @code{listen} directive sets the address and port for IP, or the
24707 path for a UNIX-domain socket on which the server will accept requests.
24708 Both address and port, or only address or only port can be specified.
24709 An address may also be a hostname, for example:
24712 '("127.0.0.1:8000" "127.0.0.1" "8000" "*:8000" "localhost:8000")
24715 @item @code{server-name} (default: @code{(list 'default)})
24716 A list of server names this server represents. @code{'default} represents the
24717 default server for connections matching no other server.
24719 @item @code{root} (default: @code{"/srv/http"})
24720 Root of the website nginx will serve.
24722 @item @code{locations} (default: @code{'()})
24723 A list of @dfn{nginx-location-configuration} or
24724 @dfn{nginx-named-location-configuration} records to use within this
24727 @item @code{index} (default: @code{(list "index.html")})
24728 Index files to look for when clients ask for a directory. If it cannot be found,
24729 Nginx will send the list of files in the directory.
24731 @item @code{try-files} (default: @code{'()})
24732 A list of files whose existence is checked in the specified order.
24733 @code{nginx} will use the first file it finds to process the request.
24735 @item @code{ssl-certificate} (default: @code{#f})
24736 Where to find the certificate for secure connections. Set it to @code{#f} if
24737 you don't have a certificate or you don't want to use HTTPS.
24739 @item @code{ssl-certificate-key} (default: @code{#f})
24740 Where to find the private key for secure connections. Set it to @code{#f} if
24741 you don't have a key or you don't want to use HTTPS.
24743 @item @code{server-tokens?} (default: @code{#f})
24744 Whether the server should add its configuration to response.
24746 @item @code{raw-content} (default: @code{'()})
24747 A list of raw lines added to the server block.
24752 @deftp {Data Type} nginx-upstream-configuration
24753 Data type representing the configuration of an nginx @code{upstream}
24754 block. This type has the following parameters:
24758 Name for this group of servers.
24760 @item @code{servers}
24761 Specify the addresses of the servers in the group. The address can be
24762 specified as a IP address (e.g.@: @samp{127.0.0.1}), domain name
24763 (e.g.@: @samp{backend1.example.com}) or a path to a UNIX socket using the
24764 prefix @samp{unix:}. For addresses using an IP address or domain name,
24765 the default port is 80, and a different port can be specified
24771 @deftp {Data Type} nginx-location-configuration
24772 Data type representing the configuration of an nginx @code{location}
24773 block. This type has the following parameters:
24777 URI which this location block matches.
24779 @anchor{nginx-location-configuration body}
24781 Body of the location block, specified as a list of strings. This can contain
24783 configuration directives. For example, to pass requests to a upstream
24784 server group defined using an @code{nginx-upstream-configuration} block,
24785 the following directive would be specified in the body @samp{(list "proxy_pass
24786 http://upstream-name;")}.
24791 @deftp {Data Type} nginx-named-location-configuration
24792 Data type representing the configuration of an nginx named location
24793 block. Named location blocks are used for request redirection, and not
24794 used for regular request processing. This type has the following
24799 Name to identify this location block.
24802 @xref{nginx-location-configuration body}, as the body for named location
24803 blocks can be used in a similar way to the
24804 @code{nginx-location-configuration body}. One restriction is that the
24805 body of a named location block cannot contain location blocks.
24810 @subsubheading Varnish Cache
24812 Varnish is a fast cache server that sits in between web applications
24813 and end users. It proxies requests from clients and caches the
24814 accessed URLs such that multiple requests for the same resource only
24815 creates one request to the back-end.
24817 @defvr {Scheme Variable} varnish-service-type
24818 Service type for the Varnish daemon.
24821 @deftp {Data Type} varnish-configuration
24822 Data type representing the @code{varnish} service configuration.
24823 This type has the following parameters:
24826 @item @code{package} (default: @code{varnish})
24827 The Varnish package to use.
24829 @item @code{name} (default: @code{"default"})
24830 A name for this Varnish instance. Varnish will create a directory in
24831 @file{/var/varnish/} with this name and keep temporary files there. If
24832 the name starts with a forward slash, it is interpreted as an absolute
24835 Pass the @code{-n} argument to other Varnish programs to connect to the
24836 named instance, e.g.@: @command{varnishncsa -n default}.
24838 @item @code{backend} (default: @code{"localhost:8080"})
24839 The backend to use. This option has no effect if @code{vcl} is set.
24841 @item @code{vcl} (default: #f)
24842 The @dfn{VCL} (Varnish Configuration Language) program to run. If this
24843 is @code{#f}, Varnish will proxy @code{backend} using the default
24844 configuration. Otherwise this must be a file-like object with valid
24847 @c Varnish does not support HTTPS, so keep this URL to avoid confusion.
24848 For example, to mirror @url{https://www.gnu.org,www.gnu.org} with VCL you
24849 can do something along these lines:
24852 (define %gnu-mirror
24853 (plain-file "gnu.vcl"
24855 backend gnu @{ .host = \"www.gnu.org\"; @}"))
24859 (services (cons (service varnish-service-type
24860 (varnish-configuration
24862 (vcl %gnu-mirror)))
24866 The configuration of an already running Varnish instance can be inspected
24867 and changed using the @command{varnishadm} program.
24869 Consult the @url{https://varnish-cache.org/docs/,Varnish User Guide} and
24870 @url{https://book.varnish-software.com/4.0/,Varnish Book} for
24871 comprehensive documentation on Varnish and its configuration language.
24873 @item @code{listen} (default: @code{'("localhost:80")})
24874 List of addresses Varnish will listen on.
24876 @item @code{storage} (default: @code{'("malloc,128m")})
24877 List of storage backends that will be available in VCL.
24879 @item @code{parameters} (default: @code{'()})
24880 List of run-time parameters in the form @code{'(("parameter" . "value"))}.
24882 @item @code{extra-options} (default: @code{'()})
24883 Additional arguments to pass to the @command{varnishd} process.
24888 @subsubheading Patchwork
24890 Patchwork is a patch tracking system. It can collect patches sent to a
24891 mailing list, and display them in a web interface.
24893 @defvr {Scheme Variable} patchwork-service-type
24894 Service type for Patchwork.
24897 The following example is an example of a minimal service for Patchwork, for
24898 the @code{patchwork.example.com} domain.
24901 (service patchwork-service-type
24902 (patchwork-configuration
24903 (domain "patchwork.example.com")
24905 (patchwork-settings-module
24906 (allowed-hosts (list domain))
24907 (default-from-email "patchwork@@patchwork.example.com")))
24908 (getmail-retriever-config
24909 (getmail-retriever-configuration
24910 (type "SimpleIMAPSSLRetriever")
24911 (server "imap.example.com")
24913 (username "patchwork")
24915 (list (file-append coreutils "/bin/cat")
24916 "/etc/getmail-patchwork-imap-password"))
24918 '((mailboxes . ("Patches"))))))))
24922 There are three records for configuring the Patchwork service. The
24923 @code{<patchwork-configuration>} relates to the configuration for Patchwork
24924 within the HTTPD service.
24926 The @code{settings-module} field within the @code{<patchwork-configuration>}
24927 record can be populated with the @code{<patchwork-settings-module>} record,
24928 which describes a settings module that is generated within the Guix store.
24930 For the @code{database-configuration} field within the
24931 @code{<patchwork-settings-module>}, the
24932 @code{<patchwork-database-configuration>} must be used.
24934 @deftp {Data Type} patchwork-configuration
24935 Data type representing the Patchwork service configuration. This type has the
24936 following parameters:
24939 @item @code{patchwork} (default: @code{patchwork})
24940 The Patchwork package to use.
24942 @item @code{domain}
24943 The domain to use for Patchwork, this is used in the HTTPD service virtual
24946 @item @code{settings-module}
24947 The settings module to use for Patchwork. As a Django application, Patchwork
24948 is configured with a Python module containing the settings. This can either be
24949 an instance of the @code{<patchwork-settings-module>} record, any other record
24950 that represents the settings in the store, or a directory outside of the
24953 @item @code{static-path} (default: @code{"/static/"})
24954 The path under which the HTTPD service should serve the static files.
24956 @item @code{getmail-retriever-config}
24957 The getmail-retriever-configuration record value to use with
24958 Patchwork. Getmail will be configured with this value, the messages will be
24959 delivered to Patchwork.
24964 @deftp {Data Type} patchwork-settings-module
24965 Data type representing a settings module for Patchwork. Some of these
24966 settings relate directly to Patchwork, but others relate to Django, the web
24967 framework used by Patchwork, or the Django Rest Framework library. This type
24968 has the following parameters:
24971 @item @code{database-configuration} (default: @code{(patchwork-database-configuration)})
24972 The database connection settings used for Patchwork. See the
24973 @code{<patchwork-database-configuration>} record type for more information.
24975 @item @code{secret-key-file} (default: @code{"/etc/patchwork/django-secret-key"})
24976 Patchwork, as a Django web application uses a secret key for cryptographically
24977 signing values. This file should contain a unique unpredictable value.
24979 If this file does not exist, it will be created and populated with a random
24980 value by the patchwork-setup shepherd service.
24982 This setting relates to Django.
24984 @item @code{allowed-hosts}
24985 A list of valid hosts for this Patchwork service. This should at least include
24986 the domain specified in the @code{<patchwork-configuration>} record.
24988 This is a Django setting.
24990 @item @code{default-from-email}
24991 The email address from which Patchwork should send email by default.
24993 This is a Patchwork setting.
24995 @item @code{static-url} (default: @code{#f})
24996 The URL to use when serving static assets. It can be part of a URL, or a full
24997 URL, but must end in a @code{/}.
24999 If the default value is used, the @code{static-path} value from the
25000 @code{<patchwork-configuration>} record will be used.
25002 This is a Django setting.
25004 @item @code{admins} (default: @code{'()})
25005 Email addresses to send the details of errors that occur. Each value should
25006 be a list containing two elements, the name and then the email address.
25008 This is a Django setting.
25010 @item @code{debug?} (default: @code{#f})
25011 Whether to run Patchwork in debug mode. If set to @code{#t}, detailed error
25012 messages will be shown.
25014 This is a Django setting.
25016 @item @code{enable-rest-api?} (default: @code{#t})
25017 Whether to enable the Patchwork REST API.
25019 This is a Patchwork setting.
25021 @item @code{enable-xmlrpc?} (default: @code{#t})
25022 Whether to enable the XML RPC API.
25024 This is a Patchwork setting.
25026 @item @code{force-https-links?} (default: @code{#t})
25027 Whether to use HTTPS links on Patchwork pages.
25029 This is a Patchwork setting.
25031 @item @code{extra-settings} (default: @code{""})
25032 Extra code to place at the end of the Patchwork settings module.
25037 @deftp {Data Type} patchwork-database-configuration
25038 Data type representing the database configuration for Patchwork.
25041 @item @code{engine} (default: @code{"django.db.backends.postgresql_psycopg2"})
25042 The database engine to use.
25044 @item @code{name} (default: @code{"patchwork"})
25045 The name of the database to use.
25047 @item @code{user} (default: @code{"httpd"})
25048 The user to connect to the database as.
25050 @item @code{password} (default: @code{""})
25051 The password to use when connecting to the database.
25053 @item @code{host} (default: @code{""})
25054 The host to make the database connection to.
25056 @item @code{port} (default: @code{""})
25057 The port on which to connect to the database.
25062 @subsubheading Mumi
25064 @cindex Mumi, Debbugs Web interface
25065 @cindex Debbugs, Mumi Web interface
25066 @uref{https://git.elephly.net/gitweb.cgi?p=software/mumi.git, Mumi} is a
25067 Web interface to the Debbugs bug tracker, by default for
25068 @uref{https://bugs.gnu.org, the GNU instance}. Mumi is a Web server,
25069 but it also fetches and indexes mail retrieved from Debbugs.
25071 @defvr {Scheme Variable} mumi-service-type
25072 This is the service type for Mumi.
25075 @deftp {Data Type} mumi-configuration
25076 Data type representing the Mumi service configuration. This type has the
25080 @item @code{mumi} (default: @code{mumi})
25081 The Mumi package to use.
25083 @item @code{mailer?} (default: @code{#true})
25084 Whether to enable or disable the mailer component.
25086 @item @code{mumi-configuration-sender}
25087 The email address used as the sender for comments.
25089 @item @code{mumi-configuration-smtp}
25090 A URI to configure the SMTP settings for Mailutils. This could be
25091 something like @code{sendmail:///path/to/bin/msmtp} or any other URI
25092 supported by Mailutils. @xref{SMTP Mailboxes, SMTP Mailboxes,,
25093 mailutils, GNU@tie{}Mailutils}.
25099 @subsubheading FastCGI
25102 FastCGI is an interface between the front-end and the back-end of a web
25103 service. It is a somewhat legacy facility; new web services should
25104 generally just talk HTTP between the front-end and the back-end.
25105 However there are a number of back-end services such as PHP or the
25106 optimized HTTP Git repository access that use FastCGI, so we have
25107 support for it in Guix.
25109 To use FastCGI, you configure the front-end web server (e.g., nginx) to
25110 dispatch some subset of its requests to the fastcgi backend, which
25111 listens on a local TCP or UNIX socket. There is an intermediary
25112 @code{fcgiwrap} program that sits between the actual backend process and
25113 the web server. The front-end indicates which backend program to run,
25114 passing that information to the @code{fcgiwrap} process.
25116 @defvr {Scheme Variable} fcgiwrap-service-type
25117 A service type for the @code{fcgiwrap} FastCGI proxy.
25120 @deftp {Data Type} fcgiwrap-configuration
25121 Data type representing the configuration of the @code{fcgiwrap} service.
25122 This type has the following parameters:
25124 @item @code{package} (default: @code{fcgiwrap})
25125 The fcgiwrap package to use.
25127 @item @code{socket} (default: @code{tcp:127.0.0.1:9000})
25128 The socket on which the @code{fcgiwrap} process should listen, as a
25129 string. Valid @var{socket} values include
25130 @code{unix:@var{/path/to/unix/socket}},
25131 @code{tcp:@var{dot.ted.qu.ad}:@var{port}} and
25132 @code{tcp6:[@var{ipv6_addr}]:port}.
25134 @item @code{user} (default: @code{fcgiwrap})
25135 @itemx @code{group} (default: @code{fcgiwrap})
25136 The user and group names, as strings, under which to run the
25137 @code{fcgiwrap} process. The @code{fastcgi} service will ensure that if
25138 the user asks for the specific user or group names @code{fcgiwrap} that
25139 the corresponding user and/or group is present on the system.
25141 It is possible to configure a FastCGI-backed web service to pass HTTP
25142 authentication information from the front-end to the back-end, and to
25143 allow @code{fcgiwrap} to run the back-end process as a corresponding
25144 local user. To enable this capability on the back-end, run
25145 @code{fcgiwrap} as the @code{root} user and group. Note that this
25146 capability also has to be configured on the front-end as well.
25151 PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation
25152 with some additional features useful for sites of any size.
25154 These features include:
25156 @item Adaptive process spawning
25157 @item Basic statistics (similar to Apache's mod_status)
25158 @item Advanced process management with graceful stop/start
25159 @item Ability to start workers with different uid/gid/chroot/environment
25160 and different php.ini (replaces safe_mode)
25161 @item Stdout & stderr logging
25162 @item Emergency restart in case of accidental opcode cache destruction
25163 @item Accelerated upload support
25164 @item Support for a "slowlog"
25165 @item Enhancements to FastCGI, such as fastcgi_finish_request() -
25166 a special function to finish request & flush all data while continuing to do
25167 something time-consuming (video converting, stats processing, etc.)
25169 ...@: and much more.
25171 @defvr {Scheme Variable} php-fpm-service-type
25172 A Service type for @code{php-fpm}.
25175 @deftp {Data Type} php-fpm-configuration
25176 Data Type for php-fpm service configuration.
25178 @item @code{php} (default: @code{php})
25179 The php package to use.
25180 @item @code{socket} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.sock")})
25181 The address on which to accept FastCGI requests. Valid syntaxes are:
25183 @item @code{"ip.add.re.ss:port"}
25184 Listen on a TCP socket to a specific address on a specific port.
25185 @item @code{"port"}
25186 Listen on a TCP socket to all addresses on a specific port.
25187 @item @code{"/path/to/unix/socket"}
25188 Listen on a unix socket.
25191 @item @code{user} (default: @code{php-fpm})
25192 User who will own the php worker processes.
25193 @item @code{group} (default: @code{php-fpm})
25194 Group of the worker processes.
25195 @item @code{socket-user} (default: @code{php-fpm})
25196 User who can speak to the php-fpm socket.
25197 @item @code{socket-group} (default: @code{nginx})
25198 Group that can speak to the php-fpm socket.
25199 @item @code{pid-file} (default: @code{(string-append "/var/run/php" (version-major (package-version php)) "-fpm.pid")})
25200 The process id of the php-fpm process is written to this file
25201 once the service has started.
25202 @item @code{log-file} (default: @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.log")})
25203 Log for the php-fpm master process.
25204 @item @code{process-manager} (default: @code{(php-fpm-dynamic-process-manager-configuration)})
25205 Detailed settings for the php-fpm process manager.
25208 @item @code{<php-fpm-dynamic-process-manager-configuration>}
25209 @item @code{<php-fpm-static-process-manager-configuration>}
25210 @item @code{<php-fpm-on-demand-process-manager-configuration>}
25212 @item @code{display-errors} (default @code{#f})
25213 Determines whether php errors and warning should be sent to clients
25214 and displayed in their browsers.
25215 This is useful for local php development, but a security risk for public sites,
25216 as error messages can reveal passwords and personal data.
25217 @item @code{timezone} (default @code{#f})
25218 Specifies @code{php_admin_value[date.timezone]} parameter.
25219 @item @code{workers-logfile} (default @code{(string-append "/var/log/php" (version-major (package-version php)) "-fpm.www.log")})
25220 This file will log the @code{stderr} outputs of php worker processes.
25221 Can be set to @code{#f} to disable logging.
25222 @item @code{file} (default @code{#f})
25223 An optional override of the whole configuration.
25224 You can use the @code{mixed-text-file} function or an absolute filepath for it.
25225 @item @code{php-ini-file} (default @code{#f})
25226 An optional override of the default php settings.
25227 It may be any ``file-like'' object (@pxref{G-Expressions, file-like objects}).
25228 You can use the @code{mixed-text-file} function or an absolute filepath for it.
25230 For local development it is useful to set a higher timeout and memory
25231 limit for spawned php processes. This be accomplished with the
25232 following operating system configuration snippet:
25234 (define %local-php-ini
25235 (plain-file "php.ini"
25237 max_execution_time = 1800"))
25241 (services (cons (service php-fpm-service-type
25242 (php-fpm-configuration
25243 (php-ini-file %local-php-ini)))
25247 Consult the @url{https://www.php.net/manual/en/ini.core.php,core php.ini
25248 directives} for comprehensive documentation on the acceptable
25249 @file{php.ini} directives.
25253 @deftp {Data type} php-fpm-dynamic-process-manager-configuration
25254 Data Type for the @code{dynamic} php-fpm process manager. With the
25255 @code{dynamic} process manager, spare worker processes are kept around
25256 based on it's configured limits.
25258 @item @code{max-children} (default: @code{5})
25259 Maximum of worker processes.
25260 @item @code{start-servers} (default: @code{2})
25261 How many worker processes should be started on start-up.
25262 @item @code{min-spare-servers} (default: @code{1})
25263 How many spare worker processes should be kept around at minimum.
25264 @item @code{max-spare-servers} (default: @code{3})
25265 How many spare worker processes should be kept around at maximum.
25269 @deftp {Data type} php-fpm-static-process-manager-configuration
25270 Data Type for the @code{static} php-fpm process manager. With the
25271 @code{static} process manager, an unchanging number of worker processes
25274 @item @code{max-children} (default: @code{5})
25275 Maximum of worker processes.
25279 @deftp {Data type} php-fpm-on-demand-process-manager-configuration
25280 Data Type for the @code{on-demand} php-fpm process manager. With the
25281 @code{on-demand} process manager, worker processes are only created as
25284 @item @code{max-children} (default: @code{5})
25285 Maximum of worker processes.
25286 @item @code{process-idle-timeout} (default: @code{10})
25287 The time in seconds after which a process with no requests is killed.
25292 @deffn {Scheme Procedure} nginx-php-location @
25293 [#:nginx-package nginx] @
25294 [socket (string-append "/var/run/php" @
25295 (version-major (package-version php)) @
25297 A helper function to quickly add php to an @code{nginx-server-configuration}.
25300 A simple services setup for nginx with php can look like this:
25302 (services (cons* (service dhcp-client-service-type)
25303 (service php-fpm-service-type)
25304 (service nginx-service-type
25305 (nginx-server-configuration
25306 (server-name '("example.com"))
25307 (root "/srv/http/")
25309 (list (nginx-php-location)))
25311 (ssl-certificate #f)
25312 (ssl-certificate-key #f)))
25316 @cindex cat-avatar-generator
25317 The cat avatar generator is a simple service to demonstrate the use of php-fpm
25318 in @code{Nginx}. It is used to generate cat avatar from a seed, for instance
25319 the hash of a user's email address.
25321 @deffn {Scheme Procedure} cat-avatar-generator-service @
25322 [#:cache-dir "/var/cache/cat-avatar-generator"] @
25323 [#:package cat-avatar-generator] @
25324 [#:configuration (nginx-server-configuration)]
25325 Returns an nginx-server-configuration that inherits @code{configuration}. It
25326 extends the nginx configuration to add a server block that serves @code{package},
25327 a version of cat-avatar-generator. During execution, cat-avatar-generator will
25328 be able to use @code{cache-dir} as its cache directory.
25331 A simple setup for cat-avatar-generator can look like this:
25333 (services (cons* (cat-avatar-generator-service
25335 (nginx-server-configuration
25336 (server-name '("example.com"))))
25341 @subsubheading Hpcguix-web
25343 @cindex hpcguix-web
25344 The @uref{https://github.com/UMCUGenetics/hpcguix-web/, hpcguix-web}
25345 program is a customizable web interface to browse Guix packages,
25346 initially designed for users of high-performance computing (HPC)
25349 @defvr {Scheme Variable} hpcguix-web-service-type
25350 The service type for @code{hpcguix-web}.
25353 @deftp {Data Type} hpcguix-web-configuration
25354 Data type for the hpcguix-web service configuration.
25358 A gexp (@pxref{G-Expressions}) specifying the hpcguix-web service
25359 configuration. The main items available in this spec are:
25362 @item @code{title-prefix} (default: @code{"hpcguix | "})
25363 The page title prefix.
25365 @item @code{guix-command} (default: @code{"guix"})
25366 The @command{guix} command.
25368 @item @code{package-filter-proc} (default: @code{(const #t)})
25369 A procedure specifying how to filter packages that are displayed.
25371 @item @code{package-page-extension-proc} (default: @code{(const '())})
25372 Extension package for @code{hpcguix-web}.
25374 @item @code{menu} (default: @code{'()})
25375 Additional entry in page @code{menu}.
25377 @item @code{channels} (default: @code{%default-channels})
25378 List of channels from which the package list is built (@pxref{Channels}).
25380 @item @code{package-list-expiration} (default: @code{(* 12 3600)})
25381 The expiration time, in seconds, after which the package list is rebuilt from
25382 the latest instances of the given channels.
25385 See the hpcguix-web repository for a
25386 @uref{https://github.com/UMCUGenetics/hpcguix-web/blob/master/hpcweb-configuration.scm,
25389 @item @code{package} (default: @code{hpcguix-web})
25390 The hpcguix-web package to use.
25394 A typical hpcguix-web service declaration looks like this:
25397 (service hpcguix-web-service-type
25398 (hpcguix-web-configuration
25400 #~(define site-config
25401 (hpcweb-configuration
25402 (title-prefix "Guix-HPC - ")
25403 (menu '(("/about" "ABOUT"))))))))
25407 The hpcguix-web service periodically updates the package list it publishes by
25408 pulling channels from Git. To that end, it needs to access X.509 certificates
25409 so that it can authenticate Git servers when communicating over HTTPS, and it
25410 assumes that @file{/etc/ssl/certs} contains those certificates.
25412 Thus, make sure to add @code{nss-certs} or another certificate package to the
25413 @code{packages} field of your configuration. @ref{X.509 Certificates}, for
25414 more information on X.509 certificates.
25417 @subsubheading gmnisrv
25420 The @uref{https://git.sr.ht/~sircmpwn/gmnisrv, gmnisrv} program is a
25421 simple @uref{https://gemini.circumlunar.space/, Gemini} protocol server.
25423 @deffn {Scheme Variable} gmnisrv-service-type
25424 This is the type of the gmnisrv service, whose value should be a
25425 @code{gmnisrv-configuration} object, as in this example:
25428 (service gmnisrv-service-type
25429 (gmnisrv-configuration
25430 (config-file (local-file "./my-gmnisrv.ini"))))
25434 @deftp {Data Type} gmnisrv-configuration
25435 Data type representing the configuration of gmnisrv.
25438 @item @code{package} (default: @var{gmnisrv})
25439 Package object of the gmnisrv server.
25441 @item @code{config-file} (default: @code{%default-gmnisrv-config-file})
25442 File-like object of the gmnisrv configuration file to use. The default
25443 configuration listens on port 1965 and serves files from
25444 @file{/srv/gemini}. Certificates are stored in
25445 @file{/var/lib/gemini/certs}. For more information, run @command{man
25446 gmnisrv} and @command{man gmnisrv.ini}.
25451 @subsubheading Agate
25454 The @uref{gemini://qwertqwefsday.eu/agate.gmi, Agate}
25455 (@uref{https://github.com/mbrubeck/agate, GitHub page over HTTPS})
25456 program is a simple @uref{https://gemini.circumlunar.space/, Gemini}
25457 protocol server written in Rust.
25459 @deffn {Scheme Variable} agate-service-type
25460 This is the type of the agate service, whose value should be an
25461 @code{agate-service-type} object, as in this example:
25464 (service agate-service-type
25465 (agate-configuration
25466 (content "/srv/gemini")
25467 (cert "/srv/cert.pem")
25468 (key "/srv/key.rsa")))
25471 The example above represents the minimal tweaking necessary to get Agate
25472 up and running. Specifying the path to the certificate and key is
25473 always necessary, as the Gemini protocol requires TLS by default.
25475 To obtain a certificate and a key, you could, for example, use OpenSSL,
25476 running a command similar to the following example:
25479 openssl req -x509 -newkey rsa:4096 -keyout key.rsa -out cert.pem \
25480 -days 3650 -nodes -subj "/CN=example.com"
25483 Of course, you'll have to replace @i{example.com} with your own domain
25484 name, and then point the Agate configuration towards the path of the
25485 generated key and certificate.
25489 @deftp {Data Type} agate-configuration
25490 Data type representing the configuration of Agate.
25493 @item @code{package} (default: @code{agate})
25494 The package object of the Agate server.
25496 @item @code{content} (default: @file{"/srv/gemini"})
25497 The directory from which Agate will serve files.
25499 @item @code{cert} (default: @code{#f})
25500 The path to the TLS certificate PEM file to be used for encrypted
25501 connections. Must be filled in with a value from the user.
25503 @item @code{key} (default: @code{#f})
25504 The path to the PKCS8 private key file to be used for encrypted
25505 connections. Must be filled in with a value from the user.
25507 @item @code{addr} (default: @code{'("0.0.0.0:1965" "[::]:1965")})
25508 A list of the addresses to listen on.
25510 @item @code{hostname} (default: @code{#f})
25511 The domain name of this Gemini server. Optional.
25513 @item @code{lang} (default: @code{#f})
25514 RFC 4646 language code(s) for text/gemini documents. Optional.
25516 @item @code{silent?} (default: @code{#f})
25517 Set to @code{#t} to disable logging output.
25519 @item @code{serve-secret?} (default: @code{#f})
25520 Set to @code{#t} to serve secret files (files/directories starting with
25523 @item @code{log-ip?} (default: @code{#t})
25524 Whether or not to output IP addresses when logging.
25526 @item @code{user} (default: @code{"agate"})
25527 Owner of the @code{agate} process.
25529 @item @code{group} (default: @code{"agate"})
25530 Owner's group of the @code{agate} process.
25532 @item @code{log-file} (default: @file{"/var/log/agate.log"})
25533 The file which should store the logging output of Agate.
25538 @node Certificate Services
25539 @subsection Certificate Services
25542 @cindex HTTP, HTTPS
25543 @cindex Let's Encrypt
25544 @cindex TLS certificates
25545 The @code{(gnu services certbot)} module provides a service to
25546 automatically obtain a valid TLS certificate from the Let's Encrypt
25547 certificate authority. These certificates can then be used to serve
25548 content securely over HTTPS or other TLS-based protocols, with the
25549 knowledge that the client will be able to verify the server's
25552 @url{https://letsencrypt.org/, Let's Encrypt} provides the
25553 @code{certbot} tool to automate the certification process. This tool
25554 first securely generates a key on the server. It then makes a request
25555 to the Let's Encrypt certificate authority (CA) to sign the key. The CA
25556 checks that the request originates from the host in question by using a
25557 challenge-response protocol, requiring the server to provide its
25558 response over HTTP@. If that protocol completes successfully, the CA
25559 signs the key, resulting in a certificate. That certificate is valid
25560 for a limited period of time, and therefore to continue to provide TLS
25561 services, the server needs to periodically ask the CA to renew its
25564 The certbot service automates this process: the initial key
25565 generation, the initial certification request to the Let's Encrypt
25566 service, the web server challenge/response integration, writing the
25567 certificate to disk, the automated periodic renewals, and the deployment
25568 tasks associated with the renewal (e.g.@: reloading services, copying keys
25569 with different permissions).
25571 Certbot is run twice a day, at a random minute within the hour. It
25572 won't do anything until your certificates are due for renewal or
25573 revoked, but running it regularly would give your service a chance of
25574 staying online in case a Let's Encrypt-initiated revocation happened for
25577 By using this service, you agree to the ACME Subscriber Agreement, which
25578 can be found there:
25579 @url{https://acme-v01.api.letsencrypt.org/directory}.
25581 @defvr {Scheme Variable} certbot-service-type
25582 A service type for the @code{certbot} Let's Encrypt client. Its value
25583 must be a @code{certbot-configuration} record as in this example:
25586 (define %nginx-deploy-hook
25588 "nginx-deploy-hook"
25589 #~(let ((pid (call-with-input-file "/var/run/nginx/pid" read)))
25590 (kill pid SIGHUP))))
25592 (service certbot-service-type
25593 (certbot-configuration
25594 (email "foo@@example.net")
25597 (certificate-configuration
25598 (domains '("example.net" "www.example.net"))
25599 (deploy-hook %nginx-deploy-hook))
25600 (certificate-configuration
25601 (domains '("bar.example.net")))))))
25604 See below for details about @code{certbot-configuration}.
25607 @deftp {Data Type} certbot-configuration
25608 Data type representing the configuration of the @code{certbot} service.
25609 This type has the following parameters:
25612 @item @code{package} (default: @code{certbot})
25613 The certbot package to use.
25615 @item @code{webroot} (default: @code{/var/www})
25616 The directory from which to serve the Let's Encrypt challenge/response
25619 @item @code{certificates} (default: @code{()})
25620 A list of @code{certificates-configuration}s for which to generate
25621 certificates and request signatures. Each certificate has a @code{name}
25622 and several @code{domains}.
25624 @item @code{email} (default: @code{#f})
25625 Optional email address used for registration and recovery contact.
25626 Setting this is encouraged as it allows you to receive important
25627 notifications about the account and issued certificates.
25629 @item @code{server} (default: @code{#f})
25630 Optional URL of ACME server. Setting this overrides certbot's default,
25631 which is the Let's Encrypt server.
25633 @item @code{rsa-key-size} (default: @code{2048})
25634 Size of the RSA key.
25636 @item @code{default-location} (default: @i{see below})
25637 The default @code{nginx-location-configuration}. Because @code{certbot}
25638 needs to be able to serve challenges and responses, it needs to be able
25639 to run a web server. It does so by extending the @code{nginx} web
25640 service with an @code{nginx-server-configuration} listening on the
25641 @var{domains} on port 80, and which has a
25642 @code{nginx-location-configuration} for the @code{/.well-known/} URI
25643 path subspace used by Let's Encrypt. @xref{Web Services}, for more on
25644 these nginx configuration data types.
25646 Requests to other URL paths will be matched by the
25647 @code{default-location}, which if present is added to all
25648 @code{nginx-server-configuration}s.
25650 By default, the @code{default-location} will issue a redirect from
25651 @code{http://@var{domain}/...} to @code{https://@var{domain}/...}, leaving
25652 you to define what to serve on your site via @code{https}.
25654 Pass @code{#f} to not issue a default location.
25658 @deftp {Data Type} certificate-configuration
25659 Data type representing the configuration of a certificate.
25660 This type has the following parameters:
25663 @item @code{name} (default: @i{see below})
25664 This name is used by Certbot for housekeeping and in file paths; it
25665 doesn't affect the content of the certificate itself. To see
25666 certificate names, run @code{certbot certificates}.
25668 Its default is the first provided domain.
25670 @item @code{domains} (default: @code{()})
25671 The first domain provided will be the subject CN of the certificate, and
25672 all domains will be Subject Alternative Names on the certificate.
25674 @item @code{challenge} (default: @code{#f})
25675 The challenge type that has to be run by certbot. If @code{#f} is specified,
25676 default to the HTTP challenge. If a value is specified, defaults to the
25677 manual plugin (see @code{authentication-hook}, @code{cleanup-hook} and
25678 the documentation at @url{https://certbot.eff.org/docs/using.html#hooks}),
25679 and gives Let's Encrypt permission to log the public IP address of the
25680 requesting machine.
25682 @item @code{authentication-hook} (default: @code{#f})
25683 Command to be run in a shell once for each certificate challenge to be
25684 answered. For this command, the shell variable @code{$CERTBOT_DOMAIN}
25685 will contain the domain being authenticated, @code{$CERTBOT_VALIDATION}
25686 contains the validation string and @code{$CERTBOT_TOKEN} contains the
25687 file name of the resource requested when performing an HTTP-01 challenge.
25689 @item @code{cleanup-hook} (default: @code{#f})
25690 Command to be run in a shell once for each certificate challenge that
25691 have been answered by the @code{auth-hook}. For this command, the shell
25692 variables available in the @code{auth-hook} script are still available, and
25693 additionally @code{$CERTBOT_AUTH_OUTPUT} will contain the standard output
25694 of the @code{auth-hook} script.
25696 @item @code{deploy-hook} (default: @code{#f})
25697 Command to be run in a shell once for each successfully issued
25698 certificate. For this command, the shell variable
25699 @code{$RENEWED_LINEAGE} will point to the config live subdirectory (for
25700 example, @samp{"/etc/letsencrypt/live/example.com"}) containing the new
25701 certificates and keys; the shell variable @code{$RENEWED_DOMAINS} will
25702 contain a space-delimited list of renewed certificate domains (for
25703 example, @samp{"example.com www.example.com"}.
25708 For each @code{certificate-configuration}, the certificate is saved to
25709 @code{/etc/letsencrypt/live/@var{name}/fullchain.pem} and the key is
25710 saved to @code{/etc/letsencrypt/live/@var{name}/privkey.pem}.
25712 @subsection DNS Services
25713 @cindex DNS (domain name system)
25714 @cindex domain name system (DNS)
25716 The @code{(gnu services dns)} module provides services related to the
25717 @dfn{domain name system} (DNS). It provides a server service for hosting
25718 an @emph{authoritative} DNS server for multiple zones, slave or master.
25719 This service uses @uref{https://www.knot-dns.cz/, Knot DNS}. And also a
25720 caching and forwarding DNS server for the LAN, which uses
25721 @uref{http://www.thekelleys.org.uk/dnsmasq/doc.html, dnsmasq}.
25723 @subsubheading Knot Service
25725 An example configuration of an authoritative server for two zones, one master
25729 (define-zone-entries example.org.zone
25730 ;; Name TTL Class Type Data
25731 ("@@" "" "IN" "A" "127.0.0.1")
25732 ("@@" "" "IN" "NS" "ns")
25733 ("ns" "" "IN" "A" "127.0.0.1"))
25735 (define master-zone
25736 (knot-zone-configuration
25737 (domain "example.org")
25739 (origin "example.org")
25740 (entries example.org.zone)))))
25743 (knot-zone-configuration
25744 (domain "plop.org")
25745 (dnssec-policy "default")
25746 (master (list "plop-master"))))
25748 (define plop-master
25749 (knot-remote-configuration
25751 (address (list "208.76.58.171"))))
25755 (services (cons* (service knot-service-type
25756 (knot-configuration
25757 (remotes (list plop-master))
25758 (zones (list master-zone slave-zone))))
25763 @deffn {Scheme Variable} knot-service-type
25764 This is the type for the Knot DNS server.
25766 Knot DNS is an authoritative DNS server, meaning that it can serve multiple
25767 zones, that is to say domain names you would buy from a registrar. This server
25768 is not a resolver, meaning that it can only resolve names for which it is
25769 authoritative. This server can be configured to serve zones as a master server
25770 or a slave server as a per-zone basis. Slave zones will get their data from
25771 masters, and will serve it as an authoritative server. From the point of view
25772 of a resolver, there is no difference between master and slave.
25774 The following data types are used to configure the Knot DNS server:
25777 @deftp {Data Type} knot-key-configuration
25778 Data type representing a key.
25779 This type has the following parameters:
25782 @item @code{id} (default: @code{""})
25783 An identifier for other configuration fields to refer to this key. IDs must
25784 be unique and must not be empty.
25786 @item @code{algorithm} (default: @code{#f})
25787 The algorithm to use. Choose between @code{#f}, @code{'hmac-md5},
25788 @code{'hmac-sha1}, @code{'hmac-sha224}, @code{'hmac-sha256}, @code{'hmac-sha384}
25789 and @code{'hmac-sha512}.
25791 @item @code{secret} (default: @code{""})
25792 The secret key itself.
25797 @deftp {Data Type} knot-acl-configuration
25798 Data type representing an Access Control List (ACL) configuration.
25799 This type has the following parameters:
25802 @item @code{id} (default: @code{""})
25803 An identifier for other configuration fields to refer to this key. IDs must be
25804 unique and must not be empty.
25806 @item @code{address} (default: @code{'()})
25807 An ordered list of IP addresses, network subnets, or network ranges represented
25808 with strings. The query must match one of them. Empty value means that
25809 address match is not required.
25811 @item @code{key} (default: @code{'()})
25812 An ordered list of references to keys represented with strings. The string
25813 must match a key ID defined in a @code{knot-key-configuration}. No key means
25814 that a key is not require to match that ACL.
25816 @item @code{action} (default: @code{'()})
25817 An ordered list of actions that are permitted or forbidden by this ACL@. Possible
25818 values are lists of zero or more elements from @code{'transfer}, @code{'notify}
25819 and @code{'update}.
25821 @item @code{deny?} (default: @code{#f})
25822 When true, the ACL defines restrictions. Listed actions are forbidden. When
25823 false, listed actions are allowed.
25828 @deftp {Data Type} zone-entry
25829 Data type representing a record entry in a zone file.
25830 This type has the following parameters:
25833 @item @code{name} (default: @code{"@@"})
25834 The name of the record. @code{"@@"} refers to the origin of the zone. Names
25835 are relative to the origin of the zone. For example, in the @code{example.org}
25836 zone, @code{"ns.example.org"} actually refers to @code{ns.example.org.example.org}.
25837 Names ending with a dot are absolute, which means that @code{"ns.example.org."}
25838 refers to @code{ns.example.org}.
25840 @item @code{ttl} (default: @code{""})
25841 The Time-To-Live (TTL) of this record. If not set, the default TTL is used.
25843 @item @code{class} (default: @code{"IN"})
25844 The class of the record. Knot currently supports only @code{"IN"} and
25845 partially @code{"CH"}.
25847 @item @code{type} (default: @code{"A"})
25848 The type of the record. Common types include A (IPv4 address), AAAA (IPv6
25849 address), NS (Name Server) and MX (Mail eXchange). Many other types are
25852 @item @code{data} (default: @code{""})
25853 The data contained in the record. For instance an IP address associated with
25854 an A record, or a domain name associated with an NS record. Remember that
25855 domain names are relative to the origin unless they end with a dot.
25860 @deftp {Data Type} zone-file
25861 Data type representing the content of a zone file.
25862 This type has the following parameters:
25865 @item @code{entries} (default: @code{'()})
25866 The list of entries. The SOA record is taken care of, so you don't need to
25867 put it in the list of entries. This list should probably contain an entry
25868 for your primary authoritative DNS server. Other than using a list of entries
25869 directly, you can use @code{define-zone-entries} to define a object containing
25870 the list of entries more easily, that you can later pass to the @code{entries}
25871 field of the @code{zone-file}.
25873 @item @code{origin} (default: @code{""})
25874 The name of your zone. This parameter cannot be empty.
25876 @item @code{ns} (default: @code{"ns"})
25877 The domain of your primary authoritative DNS server. The name is relative to
25878 the origin, unless it ends with a dot. It is mandatory that this primary
25879 DNS server corresponds to an NS record in the zone and that it is associated
25880 to an IP address in the list of entries.
25882 @item @code{mail} (default: @code{"hostmaster"})
25883 An email address people can contact you at, as the owner of the zone. This
25884 is translated as @code{<mail>@@<origin>}.
25886 @item @code{serial} (default: @code{1})
25887 The serial number of the zone. As this is used to keep track of changes by
25888 both slaves and resolvers, it is mandatory that it @emph{never} decreases.
25889 Always increment it when you make a change in your zone.
25891 @item @code{refresh} (default: @code{(* 2 24 3600)})
25892 The frequency at which slaves will do a zone transfer. This value is a number
25893 of seconds. It can be computed by multiplications or with
25894 @code{(string->duration)}.
25896 @item @code{retry} (default: @code{(* 15 60)})
25897 The period after which a slave will retry to contact its master when it fails
25898 to do so a first time.
25900 @item @code{expiry} (default: @code{(* 14 24 3600)})
25901 Default TTL of records. Existing records are considered correct for at most
25902 this amount of time. After this period, resolvers will invalidate their cache
25903 and check again that it still exists.
25905 @item @code{nx} (default: @code{3600})
25906 Default TTL of inexistant records. This delay is usually short because you want
25907 your new domains to reach everyone quickly.
25912 @deftp {Data Type} knot-remote-configuration
25913 Data type representing a remote configuration.
25914 This type has the following parameters:
25917 @item @code{id} (default: @code{""})
25918 An identifier for other configuration fields to refer to this remote. IDs must
25919 be unique and must not be empty.
25921 @item @code{address} (default: @code{'()})
25922 An ordered list of destination IP addresses. Addresses are tried in sequence.
25923 An optional port can be given with the @@ separator. For instance:
25924 @code{(list "1.2.3.4" "2.3.4.5@@53")}. Default port is 53.
25926 @item @code{via} (default: @code{'()})
25927 An ordered list of source IP addresses. An empty list will have Knot choose
25928 an appropriate source IP@. An optional port can be given with the @@ separator.
25929 The default is to choose at random.
25931 @item @code{key} (default: @code{#f})
25932 A reference to a key, that is a string containing the identifier of a key
25933 defined in a @code{knot-key-configuration} field.
25938 @deftp {Data Type} knot-keystore-configuration
25939 Data type representing a keystore to hold dnssec keys.
25940 This type has the following parameters:
25943 @item @code{id} (default: @code{""})
25944 The id of the keystore. It must not be empty.
25946 @item @code{backend} (default: @code{'pem})
25947 The backend to store the keys in. Can be @code{'pem} or @code{'pkcs11}.
25949 @item @code{config} (default: @code{"/var/lib/knot/keys/keys"})
25950 The configuration string of the backend. An example for the PKCS#11 is:
25951 @code{"pkcs11:token=knot;pin-value=1234 /gnu/store/.../lib/pkcs11/libsofthsm2.so"}.
25952 For the pem backend, the string represents a path in the file system.
25957 @deftp {Data Type} knot-policy-configuration
25958 Data type representing a dnssec policy. Knot DNS is able to automatically
25959 sign your zones. It can either generate and manage your keys automatically or
25960 use keys that you generate.
25962 Dnssec is usually implemented using two keys: a Key Signing Key (KSK) that is
25963 used to sign the second, and a Zone Signing Key (ZSK) that is used to sign the
25964 zone. In order to be trusted, the KSK needs to be present in the parent zone
25965 (usually a top-level domain). If your registrar supports dnssec, you will
25966 have to send them your KSK's hash so they can add a DS record in their zone.
25967 This is not automated and need to be done each time you change your KSK.
25969 The policy also defines the lifetime of keys. Usually, ZSK can be changed
25970 easily and use weaker cryptographic functions (they use lower parameters) in
25971 order to sign records quickly, so they are changed often. The KSK however
25972 requires manual interaction with the registrar, so they are changed less often
25973 and use stronger parameters because they sign only one record.
25975 This type has the following parameters:
25978 @item @code{id} (default: @code{""})
25979 The id of the policy. It must not be empty.
25981 @item @code{keystore} (default: @code{"default"})
25982 A reference to a keystore, that is a string containing the identifier of a
25983 keystore defined in a @code{knot-keystore-configuration} field. The
25984 @code{"default"} identifier means the default keystore (a kasp database that
25985 was setup by this service).
25987 @item @code{manual?} (default: @code{#f})
25988 Whether the key management is manual or automatic.
25990 @item @code{single-type-signing?} (default: @code{#f})
25991 When @code{#t}, use the Single-Type Signing Scheme.
25993 @item @code{algorithm} (default: @code{"ecdsap256sha256"})
25994 An algorithm of signing keys and issued signatures.
25996 @item @code{ksk-size} (default: @code{256})
25997 The length of the KSK@. Note that this value is correct for the default
25998 algorithm, but would be unsecure for other algorithms.
26000 @item @code{zsk-size} (default: @code{256})
26001 The length of the ZSK@. Note that this value is correct for the default
26002 algorithm, but would be unsecure for other algorithms.
26004 @item @code{dnskey-ttl} (default: @code{'default})
26005 The TTL value for DNSKEY records added into zone apex. The special
26006 @code{'default} value means same as the zone SOA TTL.
26008 @item @code{zsk-lifetime} (default: @code{(* 30 24 3600)})
26009 The period between ZSK publication and the next rollover initiation.
26011 @item @code{propagation-delay} (default: @code{(* 24 3600)})
26012 An extra delay added for each key rollover step. This value should be high
26013 enough to cover propagation of data from the master server to all slaves.
26015 @item @code{rrsig-lifetime} (default: @code{(* 14 24 3600)})
26016 A validity period of newly issued signatures.
26018 @item @code{rrsig-refresh} (default: @code{(* 7 24 3600)})
26019 A period how long before a signature expiration the signature will be refreshed.
26021 @item @code{nsec3?} (default: @code{#f})
26022 When @code{#t}, NSEC3 will be used instead of NSEC.
26024 @item @code{nsec3-iterations} (default: @code{5})
26025 The number of additional times the hashing is performed.
26027 @item @code{nsec3-salt-length} (default: @code{8})
26028 The length of a salt field in octets, which is appended to the original owner
26029 name before hashing.
26031 @item @code{nsec3-salt-lifetime} (default: @code{(* 30 24 3600)})
26032 The validity period of newly issued salt field.
26037 @deftp {Data Type} knot-zone-configuration
26038 Data type representing a zone served by Knot.
26039 This type has the following parameters:
26042 @item @code{domain} (default: @code{""})
26043 The domain served by this configuration. It must not be empty.
26045 @item @code{file} (default: @code{""})
26046 The file where this zone is saved. This parameter is ignored by master zones.
26047 Empty means default location that depends on the domain name.
26049 @item @code{zone} (default: @code{(zone-file)})
26050 The content of the zone file. This parameter is ignored by slave zones. It
26051 must contain a zone-file record.
26053 @item @code{master} (default: @code{'()})
26054 A list of master remotes. When empty, this zone is a master. When set, this
26055 zone is a slave. This is a list of remotes identifiers.
26057 @item @code{ddns-master} (default: @code{#f})
26058 The main master. When empty, it defaults to the first master in the list of
26061 @item @code{notify} (default: @code{'()})
26062 A list of slave remote identifiers.
26064 @item @code{acl} (default: @code{'()})
26065 A list of acl identifiers.
26067 @item @code{semantic-checks?} (default: @code{#f})
26068 When set, this adds more semantic checks to the zone.
26070 @item @code{disable-any?} (default: @code{#f})
26071 When set, this forbids queries of the ANY type.
26073 @item @code{zonefile-sync} (default: @code{0})
26074 The delay between a modification in memory and on disk. 0 means immediate
26077 @item @code{zonefile-load} (default: @code{#f})
26078 The way the zone file contents are applied during zone load. Possible values
26082 @item @code{#f} for using the default value from Knot,
26083 @item @code{'none} for not using the zone file at all,
26084 @item @code{'difference} for computing the difference between already available
26085 contents and zone contents and applying it to the current zone contents,
26086 @item @code{'difference-no-serial} for the same as @code{'difference}, but
26087 ignoring the SOA serial in the zone file, while the server takes care of it
26089 @item @code{'whole} for loading zone contents from the zone file.
26092 @item @code{journal-content} (default: @code{#f})
26093 The way the journal is used to store zone and its changes. Possible values
26094 are @code{'none} to not use it at all, @code{'changes} to store changes and
26095 @code{'all} to store contents. @code{#f} does not set this option, so the
26096 default value from Knot is used.
26098 @item @code{max-journal-usage} (default: @code{#f})
26099 The maximum size for the journal on disk. @code{#f} does not set this option,
26100 so the default value from Knot is used.
26102 @item @code{max-journal-depth} (default: @code{#f})
26103 The maximum size of the history. @code{#f} does not set this option, so the
26104 default value from Knot is used.
26106 @item @code{max-zone-size} (default: @code{#f})
26107 The maximum size of the zone file. This limit is enforced for incoming
26108 transfer and updates. @code{#f} does not set this option, so the default
26109 value from Knot is used.
26111 @item @code{dnssec-policy} (default: @code{#f})
26112 A reference to a @code{knot-policy-configuration} record, or the special
26113 name @code{"default"}. If the value is @code{#f}, there is no dnssec signing
26116 @item @code{serial-policy} (default: @code{'increment})
26117 A policy between @code{'increment} and @code{'unixtime}.
26122 @deftp {Data Type} knot-configuration
26123 Data type representing the Knot configuration.
26124 This type has the following parameters:
26127 @item @code{knot} (default: @code{knot})
26130 @item @code{run-directory} (default: @code{"/var/run/knot"})
26131 The run directory. This directory will be used for pid file and sockets.
26133 @item @code{includes} (default: @code{'()})
26134 A list of strings or file-like objects denoting other files that must be
26135 included at the top of the configuration file.
26137 @cindex secrets, Knot service
26138 This can be used to manage secrets out-of-band. For example, secret
26139 keys may be stored in an out-of-band file not managed by Guix, and
26140 thus not visible in @file{/gnu/store}---e.g., you could store secret
26141 key configuration in @file{/etc/knot/secrets.conf} and add this file
26142 to the @code{includes} list.
26144 One can generate a secret tsig key (for nsupdate and zone transfers with the
26145 keymgr command from the knot package. Note that the package is not automatically
26146 installed by the service. The following example shows how to generate a new
26150 keymgr -t mysecret > /etc/knot/secrets.conf
26151 chmod 600 /etc/knot/secrets.conf
26154 Also note that the generated key will be named @var{mysecret}, so it is the
26155 name that needs to be used in the @var{key} field of the
26156 @code{knot-acl-configuration} record and in other places that need to refer
26159 It can also be used to add configuration not supported by this interface.
26161 @item @code{listen-v4} (default: @code{"0.0.0.0"})
26162 An ip address on which to listen.
26164 @item @code{listen-v6} (default: @code{"::"})
26165 An ip address on which to listen.
26167 @item @code{listen-port} (default: @code{53})
26168 A port on which to listen.
26170 @item @code{keys} (default: @code{'()})
26171 The list of knot-key-configuration used by this configuration.
26173 @item @code{acls} (default: @code{'()})
26174 The list of knot-acl-configuration used by this configuration.
26176 @item @code{remotes} (default: @code{'()})
26177 The list of knot-remote-configuration used by this configuration.
26179 @item @code{zones} (default: @code{'()})
26180 The list of knot-zone-configuration used by this configuration.
26185 @subsubheading Knot Resolver Service
26187 @deffn {Scheme Variable} knot-resolver-service-type
26188 This is the type of the knot resolver service, whose value should be
26189 an @code{knot-resolver-configuration} object as in this example:
26192 (service knot-resolver-service-type
26193 (knot-resolver-configuration
26194 (kresd-config-file (plain-file "kresd.conf" "
26195 net.listen('192.168.0.1', 5353)
26196 user('knot-resolver', 'knot-resolver')
26197 modules = @{ 'hints > iterate', 'stats', 'predict' @}
26198 cache.size = 100 * MB
26202 For more information, refer its @url{https://knot-resolver.readthedocs.org/en/stable/daemon.html#configuration, manual}.
26205 @deftp {Data Type} knot-resolver-configuration
26206 Data type representing the configuration of knot-resolver.
26209 @item @code{package} (default: @var{knot-resolver})
26210 Package object of the knot DNS resolver.
26212 @item @code{kresd-config-file} (default: %kresd.conf)
26213 File-like object of the kresd configuration file to use, by default it
26214 will listen on @code{127.0.0.1} and @code{::1}.
26216 @item @code{garbage-collection-interval} (default: 1000)
26217 Number of milliseconds for @code{kres-cache-gc} to periodically trim the cache.
26223 @subsubheading Dnsmasq Service
26225 @deffn {Scheme Variable} dnsmasq-service-type
26226 This is the type of the dnsmasq service, whose value should be an
26227 @code{dnsmasq-configuration} object as in this example:
26230 (service dnsmasq-service-type
26231 (dnsmasq-configuration
26233 (servers '("192.168.1.1"))))
26237 @deftp {Data Type} dnsmasq-configuration
26238 Data type representing the configuration of dnsmasq.
26241 @item @code{package} (default: @var{dnsmasq})
26242 Package object of the dnsmasq server.
26244 @item @code{no-hosts?} (default: @code{#f})
26245 When true, don't read the hostnames in /etc/hosts.
26247 @item @code{port} (default: @code{53})
26248 The port to listen on. Setting this to zero completely disables DNS
26249 responses, leaving only DHCP and/or TFTP functions.
26251 @item @code{local-service?} (default: @code{#t})
26252 Accept DNS queries only from hosts whose address is on a local subnet,
26253 ie a subnet for which an interface exists on the server.
26255 @item @code{listen-addresses} (default: @code{'()})
26256 Listen on the given IP addresses.
26258 @item @code{resolv-file} (default: @code{"/etc/resolv.conf"})
26259 The file to read the IP address of the upstream nameservers from.
26261 @item @code{no-resolv?} (default: @code{#f})
26262 When true, don't read @var{resolv-file}.
26264 @item @code{servers} (default: @code{'()})
26265 Specify IP address of upstream servers directly.
26267 @item @code{addresses} (default: @code{'()})
26268 For each entry, specify an IP address to return for any host in the
26269 given domains. Queries in the domains are never forwarded and always
26270 replied to with the specified IP address.
26272 This is useful for redirecting hosts locally, for example:
26275 (service dnsmasq-service-type
26276 (dnsmasq-configuration
26278 '(; Redirect to a local web-server.
26279 "/example.org/127.0.0.1"
26280 ; Redirect subdomain to a specific IP.
26281 "/subdomain.example.org/192.168.1.42"))))
26284 Note that rules in @file{/etc/hosts} take precedence over this.
26286 @item @code{cache-size} (default: @code{150})
26287 Set the size of dnsmasq's cache. Setting the cache size to zero
26290 @item @code{negative-cache?} (default: @code{#t})
26291 When false, disable negative caching.
26293 @item @code{tftp-enable?} (default: @code{#f})
26294 Whether to enable the built-in TFTP server.
26296 @item @code{tftp-no-fail?} (default: @code{#f})
26297 If true, does not fail dnsmasq if the TFTP server could not start up.
26299 @item @code{tftp-single-port?} (default: @code{#f})
26300 Whether to use only one single port for TFTP.
26302 @item @code{tftp-secure?} (default: @code{#f})
26303 If true, only files owned by the user running the dnsmasq process are accessible.
26305 If dnsmasq is being run as root, different rules apply:
26306 @code{tftp-secure?} has no effect, but only files which have the
26307 world-readable bit set are accessible.
26309 @item @code{tftp-max} (default: @code{#f})
26310 If set, sets the maximal number of concurrent connections allowed.
26312 @item @code{tftp-mtu} (default: @code{#f})
26313 If set, sets the MTU for TFTP packets to that value.
26315 @item @code{tftp-no-blocksize?} (default: @code{#f})
26316 If true, stops the TFTP server from negotiating the blocksize with a client.
26318 @item @code{tftp-lowercase?} (default: @code{#f})
26319 Whether to convert all filenames in TFTP requests to lowercase.
26321 @item @code{tftp-port-range} (default: @code{#f})
26322 If set, fixes the dynamical ports (one per client) to the given range
26323 (@code{"<start>,<end>"}).
26325 @item @code{tftp-root} (default: @code{/var/empty,lo})
26326 Look for files to transfer using TFTP relative to the given directory.
26327 When this is set, TFTP paths which include @samp{..} are rejected, to stop clients
26328 getting outside the specified root. Absolute paths (starting with @samp{/}) are
26329 allowed, but they must be within the TFTP-root. If the optional interface
26330 argument is given, the directory is only used for TFTP requests via that
26333 @item @code{tftp-unique-root} (default: @code{#f})
26334 If set, add the IP or hardware address of the TFTP client as a path component
26335 on the end of the TFTP-root. Only valid if a TFTP root is set and the
26336 directory exists. Defaults to adding IP address (in standard dotted-quad
26339 For instance, if @option{--tftp-root} is @samp{/tftp} and client
26340 @samp{1.2.3.4} requests file @file{myfile} then the effective path will
26341 be @file{/tftp/1.2.3.4/myfile} if @file{/tftp/1.2.3.4} exists or
26342 @file{/tftp/myfile} otherwise. When @samp{=mac} is specified it will
26343 append the MAC address instead, using lowercase zero padded digits
26344 separated by dashes, e.g.: @samp{01-02-03-04-aa-bb}. Note that
26345 resolving MAC addresses is only possible if the client is in the local
26346 network or obtained a DHCP lease from dnsmasq.
26351 @subsubheading ddclient Service
26354 The ddclient service described below runs the ddclient daemon, which takes
26355 care of automatically updating DNS entries for service providers such as
26356 @uref{https://dyn.com/dns/, Dyn}.
26358 The following example show instantiates the service with its default
26362 (service ddclient-service-type)
26365 Note that ddclient needs to access credentials that are stored in a
26366 @dfn{secret file}, by default @file{/etc/ddclient/secrets} (see
26367 @code{secret-file} below). You are expected to create this file manually, in
26368 an ``out-of-band'' fashion (you @emph{could} make this file part of the
26369 service configuration, for instance by using @code{plain-file}, but it will be
26370 world-readable @i{via} @file{/gnu/store}). See the examples in the
26371 @file{share/ddclient} directory of the @code{ddclient} package.
26373 @c %start of fragment
26375 Available @code{ddclient-configuration} fields are:
26377 @deftypevr {@code{ddclient-configuration} parameter} package ddclient
26378 The ddclient package.
26382 @deftypevr {@code{ddclient-configuration} parameter} integer daemon
26383 The period after which ddclient will retry to check IP and domain name.
26385 Defaults to @samp{300}.
26389 @deftypevr {@code{ddclient-configuration} parameter} boolean syslog
26390 Use syslog for the output.
26392 Defaults to @samp{#t}.
26396 @deftypevr {@code{ddclient-configuration} parameter} string mail
26399 Defaults to @samp{"root"}.
26403 @deftypevr {@code{ddclient-configuration} parameter} string mail-failure
26404 Mail failed update to user.
26406 Defaults to @samp{"root"}.
26410 @deftypevr {@code{ddclient-configuration} parameter} string pid
26411 The ddclient PID file.
26413 Defaults to @samp{"/var/run/ddclient/ddclient.pid"}.
26417 @deftypevr {@code{ddclient-configuration} parameter} boolean ssl
26418 Enable SSL support.
26420 Defaults to @samp{#t}.
26424 @deftypevr {@code{ddclient-configuration} parameter} string user
26425 Specifies the user name or ID that is used when running ddclient
26428 Defaults to @samp{"ddclient"}.
26432 @deftypevr {@code{ddclient-configuration} parameter} string group
26433 Group of the user who will run the ddclient program.
26435 Defaults to @samp{"ddclient"}.
26439 @deftypevr {@code{ddclient-configuration} parameter} string secret-file
26440 Secret file which will be appended to @file{ddclient.conf} file. This
26441 file contains credentials for use by ddclient. You are expected to
26442 create it manually.
26444 Defaults to @samp{"/etc/ddclient/secrets.conf"}.
26448 @deftypevr {@code{ddclient-configuration} parameter} list extra-options
26449 Extra options will be appended to @file{ddclient.conf} file.
26451 Defaults to @samp{()}.
26456 @c %end of fragment
26460 @subsection VPN Services
26461 @cindex VPN (virtual private network)
26462 @cindex virtual private network (VPN)
26464 The @code{(gnu services vpn)} module provides services related to
26465 @dfn{virtual private networks} (VPNs).
26467 @subsubheading OpenVPN
26469 It provides a @emph{client} service for your machine to connect to a
26470 VPN, and a @emph{server} service for your machine to host a VPN@.
26472 @deffn {Scheme Procedure} openvpn-client-service @
26473 [#:config (openvpn-client-configuration)]
26475 Return a service that runs @command{openvpn}, a VPN daemon, as a client.
26478 @deffn {Scheme Procedure} openvpn-server-service @
26479 [#:config (openvpn-server-configuration)]
26481 Return a service that runs @command{openvpn}, a VPN daemon, as a server.
26483 Both can be run simultaneously.
26486 @c %automatically generated documentation
26488 Available @code{openvpn-client-configuration} fields are:
26490 @deftypevr {@code{openvpn-client-configuration} parameter} package openvpn
26491 The OpenVPN package.
26495 @deftypevr {@code{openvpn-client-configuration} parameter} string pid-file
26496 The OpenVPN pid file.
26498 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
26502 @deftypevr {@code{openvpn-client-configuration} parameter} proto proto
26503 The protocol (UDP or TCP) used to open a channel between clients and
26506 Defaults to @samp{udp}.
26510 @deftypevr {@code{openvpn-client-configuration} parameter} dev dev
26511 The device type used to represent the VPN connection.
26513 Defaults to @samp{tun}.
26517 If you do not have some of these files (eg.@: you use a username and
26518 password), you can disable any of the following three fields by setting
26519 it to @code{'disabled}.
26521 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string ca
26522 The certificate authority to check connections against.
26524 Defaults to @samp{"/etc/openvpn/ca.crt"}.
26528 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string cert
26529 The certificate of the machine the daemon is running on. It should be
26530 signed by the authority given in @code{ca}.
26532 Defaults to @samp{"/etc/openvpn/client.crt"}.
26536 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string key
26537 The key of the machine the daemon is running on. It must be the key whose
26538 certificate is @code{cert}.
26540 Defaults to @samp{"/etc/openvpn/client.key"}.
26544 @deftypevr {@code{openvpn-client-configuration} parameter} boolean comp-lzo?
26545 Whether to use the lzo compression algorithm.
26547 Defaults to @samp{#t}.
26551 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-key?
26552 Don't re-read key files across SIGUSR1 or --ping-restart.
26554 Defaults to @samp{#t}.
26558 @deftypevr {@code{openvpn-client-configuration} parameter} boolean persist-tun?
26559 Don't close and reopen TUN/TAP device or run up/down scripts across
26560 SIGUSR1 or --ping-restart restarts.
26562 Defaults to @samp{#t}.
26566 @deftypevr {@code{openvpn-client-configuration} parameter} boolean fast-io?
26567 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
26568 poll/epoll/select prior to the write operation.
26570 Defaults to @samp{#f}.
26573 @deftypevr {@code{openvpn-client-configuration} parameter} number verbosity
26576 Defaults to @samp{3}.
26580 @deftypevr {@code{openvpn-client-configuration} parameter} tls-auth-client tls-auth
26581 Add an additional layer of HMAC authentication on top of the TLS control
26582 channel to protect against DoS attacks.
26584 Defaults to @samp{#f}.
26588 @deftypevr {@code{openvpn-client-configuration} parameter} maybe-string auth-user-pass
26589 Authenticate with server using username/password. The option is a file
26590 containing username/password on 2 lines. Do not use a file-like object as it
26591 would be added to the store and readable by any user.
26593 Defaults to @samp{'disabled}.
26596 @deftypevr {@code{openvpn-client-configuration} parameter} key-usage verify-key-usage?
26597 Whether to check the server certificate has server usage extension.
26599 Defaults to @samp{#t}.
26603 @deftypevr {@code{openvpn-client-configuration} parameter} bind bind?
26604 Bind to a specific local port number.
26606 Defaults to @samp{#f}.
26610 @deftypevr {@code{openvpn-client-configuration} parameter} resolv-retry resolv-retry?
26611 Retry resolving server address.
26613 Defaults to @samp{#t}.
26617 @deftypevr {@code{openvpn-client-configuration} parameter} openvpn-remote-list remote
26618 A list of remote servers to connect to.
26620 Defaults to @samp{()}.
26622 Available @code{openvpn-remote-configuration} fields are:
26624 @deftypevr {@code{openvpn-remote-configuration} parameter} string name
26627 Defaults to @samp{"my-server"}.
26631 @deftypevr {@code{openvpn-remote-configuration} parameter} number port
26632 Port number the server listens to.
26634 Defaults to @samp{1194}.
26639 @c %end of automatic openvpn-client documentation
26641 @c %automatically generated documentation
26643 Available @code{openvpn-server-configuration} fields are:
26645 @deftypevr {@code{openvpn-server-configuration} parameter} package openvpn
26646 The OpenVPN package.
26650 @deftypevr {@code{openvpn-server-configuration} parameter} string pid-file
26651 The OpenVPN pid file.
26653 Defaults to @samp{"/var/run/openvpn/openvpn.pid"}.
26657 @deftypevr {@code{openvpn-server-configuration} parameter} proto proto
26658 The protocol (UDP or TCP) used to open a channel between clients and
26661 Defaults to @samp{udp}.
26665 @deftypevr {@code{openvpn-server-configuration} parameter} dev dev
26666 The device type used to represent the VPN connection.
26668 Defaults to @samp{tun}.
26672 If you do not have some of these files (eg.@: you use a username and
26673 password), you can disable any of the following three fields by setting
26674 it to @code{'disabled}.
26676 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string ca
26677 The certificate authority to check connections against.
26679 Defaults to @samp{"/etc/openvpn/ca.crt"}.
26683 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string cert
26684 The certificate of the machine the daemon is running on. It should be
26685 signed by the authority given in @code{ca}.
26687 Defaults to @samp{"/etc/openvpn/client.crt"}.
26691 @deftypevr {@code{openvpn-server-configuration} parameter} maybe-string key
26692 The key of the machine the daemon is running on. It must be the key whose
26693 certificate is @code{cert}.
26695 Defaults to @samp{"/etc/openvpn/client.key"}.
26699 @deftypevr {@code{openvpn-server-configuration} parameter} boolean comp-lzo?
26700 Whether to use the lzo compression algorithm.
26702 Defaults to @samp{#t}.
26706 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-key?
26707 Don't re-read key files across SIGUSR1 or --ping-restart.
26709 Defaults to @samp{#t}.
26713 @deftypevr {@code{openvpn-server-configuration} parameter} boolean persist-tun?
26714 Don't close and reopen TUN/TAP device or run up/down scripts across
26715 SIGUSR1 or --ping-restart restarts.
26717 Defaults to @samp{#t}.
26721 @deftypevr {@code{openvpn-server-configuration} parameter} boolean fast-io?
26722 (Experimental) Optimize TUN/TAP/UDP I/O writes by avoiding a call to
26723 poll/epoll/select prior to the write operation.
26725 Defaults to @samp{#f}.
26728 @deftypevr {@code{openvpn-server-configuration} parameter} number verbosity
26731 Defaults to @samp{3}.
26735 @deftypevr {@code{openvpn-server-configuration} parameter} tls-auth-server tls-auth
26736 Add an additional layer of HMAC authentication on top of the TLS control
26737 channel to protect against DoS attacks.
26739 Defaults to @samp{#f}.
26743 @deftypevr {@code{openvpn-server-configuration} parameter} number port
26744 Specifies the port number on which the server listens.
26746 Defaults to @samp{1194}.
26750 @deftypevr {@code{openvpn-server-configuration} parameter} ip-mask server
26751 An ip and mask specifying the subnet inside the virtual network.
26753 Defaults to @samp{"10.8.0.0 255.255.255.0"}.
26757 @deftypevr {@code{openvpn-server-configuration} parameter} cidr6 server-ipv6
26758 A CIDR notation specifying the IPv6 subnet inside the virtual network.
26760 Defaults to @samp{#f}.
26764 @deftypevr {@code{openvpn-server-configuration} parameter} string dh
26765 The Diffie-Hellman parameters file.
26767 Defaults to @samp{"/etc/openvpn/dh2048.pem"}.
26771 @deftypevr {@code{openvpn-server-configuration} parameter} string ifconfig-pool-persist
26772 The file that records client IPs.
26774 Defaults to @samp{"/etc/openvpn/ipp.txt"}.
26778 @deftypevr {@code{openvpn-server-configuration} parameter} gateway redirect-gateway?
26779 When true, the server will act as a gateway for its clients.
26781 Defaults to @samp{#f}.
26785 @deftypevr {@code{openvpn-server-configuration} parameter} boolean client-to-client?
26786 When true, clients are allowed to talk to each other inside the VPN.
26788 Defaults to @samp{#f}.
26792 @deftypevr {@code{openvpn-server-configuration} parameter} keepalive keepalive
26793 Causes ping-like messages to be sent back and forth over the link so
26794 that each side knows when the other side has gone down. @code{keepalive}
26795 requires a pair. The first element is the period of the ping sending,
26796 and the second element is the timeout before considering the other side
26801 @deftypevr {@code{openvpn-server-configuration} parameter} number max-clients
26802 The maximum number of clients.
26804 Defaults to @samp{100}.
26808 @deftypevr {@code{openvpn-server-configuration} parameter} string status
26809 The status file. This file shows a small report on current connection.
26810 It is truncated and rewritten every minute.
26812 Defaults to @samp{"/var/run/openvpn/status"}.
26816 @deftypevr {@code{openvpn-server-configuration} parameter} openvpn-ccd-list client-config-dir
26817 The list of configuration for some clients.
26819 Defaults to @samp{()}.
26821 Available @code{openvpn-ccd-configuration} fields are:
26823 @deftypevr {@code{openvpn-ccd-configuration} parameter} string name
26826 Defaults to @samp{"client"}.
26830 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask iroute
26833 Defaults to @samp{#f}.
26837 @deftypevr {@code{openvpn-ccd-configuration} parameter} ip-mask ifconfig-push
26840 Defaults to @samp{#f}.
26847 @c %end of automatic openvpn-server documentation
26849 @subsubheading Wireguard
26851 @defvr {Scheme Variable} wireguard-service-type
26852 A service type for a Wireguard tunnel interface. Its value must be a
26853 @code{wireguard-configuration} record as in this example:
26856 (service wireguard-service-type
26857 (wireguard-configuration
26862 (endpoint "my.wireguard.com:51820")
26863 (public-key "hzpKg9X1yqu1axN6iJp0mWf6BZGo8m1wteKwtTmDGF4=")
26864 (allowed-ips '("10.0.0.2/32")))))))
26869 @deftp {Data Type} wireguard-configuration
26870 Data type representing the configuration of the Wireguard service.
26873 @item @code{wireguard}
26874 The wireguard package to use for this service.
26876 @item @code{interface} (default: @code{"wg0"})
26877 The interface name for the VPN.
26879 @item @code{addresses} (default: @code{'("10.0.0.1/32")})
26880 The IP addresses to be assigned to the above interface.
26882 @item @code{private-key} (default: @code{"/etc/wireguard/private.key"})
26883 The private key file for the interface. It is automatically generated if
26884 the file does not exist.
26886 @item @code{peers} (default: @code{'()})
26887 The authorized peers on this interface. This is a list of
26888 @var{wireguard-peer} records.
26893 @deftp {Data Type} wireguard-peer
26894 Data type representing a Wireguard peer attached to a given interface.
26900 @item @code{endpoint} (default: @code{#f})
26901 The optional endpoint for the peer, such as
26902 @code{"demo.wireguard.com:51820"}.
26904 @item @code{public-key}
26905 The peer public-key represented as a base64 string.
26907 @item @code{allowed-ips}
26908 A list of IP addresses from which incoming traffic for this peer is
26909 allowed and to which incoming traffic for this peer is directed.
26914 @node Network File System
26915 @subsection Network File System
26918 The @code{(gnu services nfs)} module provides the following services,
26919 which are most commonly used in relation to mounting or exporting
26920 directory trees as @dfn{network file systems} (NFS).
26922 While it is possible to use the individual components that together make
26923 up a Network File System service, we recommended to configure an NFS
26924 server with the @code{nfs-service-type}.
26926 @subsubheading NFS Service
26927 @cindex NFS, server
26929 The NFS service takes care of setting up all NFS component services,
26930 kernel configuration file systems, and installs configuration files in
26931 the locations that NFS expects.
26933 @defvr {Scheme Variable} nfs-service-type
26934 A service type for a complete NFS server.
26937 @deftp {Data Type} nfs-configuration
26938 This data type represents the configuration of the NFS service and all
26941 It has the following parameters:
26943 @item @code{nfs-utils} (default: @code{nfs-utils})
26944 The nfs-utils package to use.
26946 @item @code{nfs-versions} (default: @code{'("4.2" "4.1" "4.0")})
26947 If a list of string values is provided, the @command{rpc.nfsd} daemon
26948 will be limited to supporting the given versions of the NFS protocol.
26950 @item @code{exports} (default: @code{'()})
26951 This is a list of directories the NFS server should export. Each entry
26952 is a list consisting of two elements: a directory name and a string
26953 containing all options. This is an example in which the directory
26954 @file{/export} is served to all NFS clients as a read-only share:
26960 "*(ro,insecure,no_subtree_check,crossmnt,fsid=0)"))))
26963 @item @code{rpcmountd-port} (default: @code{#f})
26964 The network port that the @command{rpc.mountd} daemon should use.
26966 @item @code{rpcstatd-port} (default: @code{#f})
26967 The network port that the @command{rpc.statd} daemon should use.
26969 @item @code{rpcbind} (default: @code{rpcbind})
26970 The rpcbind package to use.
26972 @item @code{idmap-domain} (default: @code{"localdomain"})
26973 The local NFSv4 domain name.
26975 @item @code{nfsd-port} (default: @code{2049})
26976 The network port that the @command{nfsd} daemon should use.
26978 @item @code{nfsd-threads} (default: @code{8})
26979 The number of threads used by the @command{nfsd} daemon.
26981 @item @code{nfsd-tcp?} (default: @code{#t})
26982 Whether the @command{nfsd} daemon should listen on a TCP socket.
26984 @item @code{nfsd-udp?} (default: @code{#f})
26985 Whether the @command{nfsd} daemon should listen on a UDP socket.
26987 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
26988 The directory where the pipefs file system is mounted.
26990 @item @code{debug} (default: @code{'()"})
26991 A list of subsystems for which debugging output should be enabled. This
26992 is a list of symbols. Any of these symbols are valid: @code{nfsd},
26993 @code{nfs}, @code{rpc}, @code{idmap}, @code{statd}, or @code{mountd}.
26997 If you don't need a complete NFS service or prefer to build it yourself
26998 you can use the individual component services that are documented below.
27000 @subsubheading RPC Bind Service
27003 The RPC Bind service provides a facility to map program numbers into
27004 universal addresses.
27005 Many NFS related services use this facility. Hence it is automatically
27006 started when a dependent service starts.
27008 @defvr {Scheme Variable} rpcbind-service-type
27009 A service type for the RPC portmapper daemon.
27013 @deftp {Data Type} rpcbind-configuration
27014 Data type representing the configuration of the RPC Bind Service.
27015 This type has the following parameters:
27017 @item @code{rpcbind} (default: @code{rpcbind})
27018 The rpcbind package to use.
27020 @item @code{warm-start?} (default: @code{#t})
27021 If this parameter is @code{#t}, then the daemon will read a
27022 state file on startup thus reloading state information saved by a previous
27028 @subsubheading Pipefs Pseudo File System
27032 The pipefs file system is used to transfer NFS related data
27033 between the kernel and user space programs.
27035 @defvr {Scheme Variable} pipefs-service-type
27036 A service type for the pipefs pseudo file system.
27039 @deftp {Data Type} pipefs-configuration
27040 Data type representing the configuration of the pipefs pseudo file system service.
27041 This type has the following parameters:
27043 @item @code{mount-point} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27044 The directory to which the file system is to be attached.
27049 @subsubheading GSS Daemon Service
27052 @cindex global security system
27054 The @dfn{global security system} (GSS) daemon provides strong security for RPC
27056 Before exchanging RPC requests an RPC client must establish a security
27057 context. Typically this is done using the Kerberos command @command{kinit}
27058 or automatically at login time using PAM services (@pxref{Kerberos Services}).
27060 @defvr {Scheme Variable} gss-service-type
27061 A service type for the Global Security System (GSS) daemon.
27064 @deftp {Data Type} gss-configuration
27065 Data type representing the configuration of the GSS daemon service.
27066 This type has the following parameters:
27068 @item @code{nfs-utils} (default: @code{nfs-utils})
27069 The package in which the @command{rpc.gssd} command is to be found.
27071 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27072 The directory where the pipefs file system is mounted.
27078 @subsubheading IDMAP Daemon Service
27080 @cindex name mapper
27082 The idmap daemon service provides mapping between user IDs and user names.
27083 Typically it is required in order to access file systems mounted via NFSv4.
27085 @defvr {Scheme Variable} idmap-service-type
27086 A service type for the Identity Mapper (IDMAP) daemon.
27089 @deftp {Data Type} idmap-configuration
27090 Data type representing the configuration of the IDMAP daemon service.
27091 This type has the following parameters:
27093 @item @code{nfs-utils} (default: @code{nfs-utils})
27094 The package in which the @command{rpc.idmapd} command is to be found.
27096 @item @code{pipefs-directory} (default: @code{"/var/lib/nfs/rpc_pipefs"})
27097 The directory where the pipefs file system is mounted.
27099 @item @code{domain} (default: @code{#f})
27100 The local NFSv4 domain name.
27101 This must be a string or @code{#f}.
27102 If it is @code{#f} then the daemon will use the host's fully qualified domain name.
27104 @item @code{verbosity} (default: @code{0})
27105 The verbosity level of the daemon.
27110 @node Continuous Integration
27111 @subsection Continuous Integration
27113 @cindex continuous integration
27114 @uref{https://guix.gnu.org/cuirass/, Cuirass} is a continuous
27115 integration tool for Guix. It can be used both for development and for
27116 providing substitutes to others (@pxref{Substitutes}).
27118 The @code{(gnu services cuirass)} module provides the following service.
27120 @defvr {Scheme Procedure} cuirass-service-type
27121 The type of the Cuirass service. Its value must be a
27122 @code{cuirass-configuration} object, as described below.
27125 To add build jobs, you have to set the @code{specifications} field of
27126 the configuration. For instance, the following example will build all
27127 the packages provided by the @code{my-channel} channel.
27130 (define %cuirass-specs
27131 #~(list (specification
27132 (name "my-channel")
27133 (build '(channels my-channel))
27137 (url "https://my-channel.git"))
27138 %default-channels)))))
27140 (service cuirass-service-type
27141 (cuirass-configuration
27142 (specifications %cuirass-specs)))
27145 To build the @code{linux-libre} package defined by the default Guix
27146 channel, one can use the following configuration.
27149 (define %cuirass-specs
27150 #~(list (specification
27152 (build '(packages "linux-libre")))))
27154 (service cuirass-service-type
27155 (cuirass-configuration
27156 (specifications %cuirass-specs)))
27159 The other configuration possibilities, as well as the specification
27160 record itself are described in the Cuirass manual
27161 (@pxref{Specifications,,, cuirass, Cuirass}).
27163 While information related to build jobs is located directly in the
27164 specifications, global settings for the @command{cuirass} process are
27165 accessible in other @code{cuirass-configuration} fields.
27167 @deftp {Data Type} cuirass-configuration
27168 Data type representing the configuration of Cuirass.
27171 @item @code{cuirass} (default: @code{cuirass})
27172 The Cuirass package to use.
27174 @item @code{log-file} (default: @code{"/var/log/cuirass.log"})
27175 Location of the log file.
27177 @item @code{web-log-file} (default: @code{"/var/log/cuirass-web.log"})
27178 Location of the log file used by the web interface.
27180 @item @code{cache-directory} (default: @code{"/var/cache/cuirass"})
27181 Location of the repository cache.
27183 @item @code{user} (default: @code{"cuirass"})
27184 Owner of the @code{cuirass} process.
27186 @item @code{group} (default: @code{"cuirass"})
27187 Owner's group of the @code{cuirass} process.
27189 @item @code{interval} (default: @code{60})
27190 Number of seconds between the poll of the repositories followed by the
27193 @item @code{parameters} (default: @code{#f})
27194 Read parameters from the given @var{parameters} file. The supported
27195 parameters are described here (@pxref{Parameters,,, cuirass, Cuirass}).
27197 @item @code{remote-server} (default: @code{#f})
27198 A @code{cuirass-remote-server-configuration} record to use the build
27199 remote mechanism or @code{#f} to use the default build mechanism.
27201 @item @code{database} (default: @code{"dbname=cuirass host=/var/run/postgresql"})
27202 Use @var{database} as the database containing the jobs and the past
27203 build results. Since Cuirass uses PostgreSQL as a database engine,
27204 @var{database} must be a string such as @code{"dbname=cuirass
27207 @item @code{port} (default: @code{8081})
27208 Port number used by the HTTP server.
27210 @item @code{host} (default: @code{"localhost"})
27211 Listen on the network interface for @var{host}. The default is to
27212 accept connections from localhost.
27214 @item @code{specifications} (default: @code{#~'()})
27215 A gexp (@pxref{G-Expressions}) that evaluates to a list of
27216 specifications records. The specification record is described in the
27217 Cuirass manual (@pxref{Specifications,,, cuirass, Cuirass}).
27219 @item @code{use-substitutes?} (default: @code{#f})
27220 This allows using substitutes to avoid building every dependencies of a job
27223 @item @code{one-shot?} (default: @code{#f})
27224 Only evaluate specifications and build derivations once.
27226 @item @code{fallback?} (default: @code{#f})
27227 When substituting a pre-built binary fails, fall back to building
27230 @item @code{extra-options} (default: @code{'()})
27231 Extra options to pass when running the Cuirass processes.
27236 @cindex remote build
27237 @subsubheading Cuirass remote building
27239 Cuirass supports two mechanisms to build derivations.
27242 @item Using the local Guix daemon.
27243 This is the default build mechanism. Once the build jobs are
27244 evaluated, they are sent to the local Guix daemon. Cuirass then
27245 listens to the Guix daemon output to detect the various build events.
27247 @item Using the remote build mechanism.
27248 The build jobs are not submitted to the local Guix daemon. Instead, a
27249 remote server dispatches build requests to the connect remote workers,
27250 according to the build priorities.
27254 To enable this build mode a @code{cuirass-remote-server-configuration}
27255 record must be passed as @code{remote-server} argument of the
27256 @code{cuirass-configuration} record. The
27257 @code{cuirass-remote-server-configuration} record is described below.
27259 This build mode scales way better than the default build mode. This is
27260 the build mode that is used on the GNU Guix build farm at
27261 @url{https://ci.guix.gnu.org}. It should be preferred when using
27262 Cuirass to build large amount of packages.
27264 @deftp {Data Type} cuirass-remote-server-configuration
27265 Data type representing the configuration of the Cuirass remote-server.
27268 @item @code{backend-port} (default: @code{5555})
27269 The TCP port for communicating with @code{remote-worker} processes
27270 using ZMQ. It defaults to @code{5555}.
27272 @item @code{log-port} (default: @code{5556})
27273 The TCP port of the log server. It defaults to @code{5556}.
27275 @item @code{publish-port} (default: @code{5557})
27276 The TCP port of the publish server. It defaults to @code{5557}.
27278 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-server.log"})
27279 Location of the log file.
27281 @item @code{cache} (default: @code{"/var/cache/cuirass/remote"})
27282 Use @var{cache} directory to cache build log files.
27284 @item @code{trigger-url} (default: @code{#f})
27285 Once a substitute is successfully fetched, trigger substitute baking at
27288 @item @code{public-key}
27289 @item @code{private-key}
27290 Use the specific @var{file}s as the public/private key pair used to sign
27291 the store items being published.
27296 At least one remote worker must also be started on any machine of the
27297 local network to actually perform the builds and report their status.
27299 @deftp {Data Type} cuirass-remote-worker-configuration
27300 Data type representing the configuration of the Cuirass remote-worker.
27303 @item @code{cuirass} (default: @code{cuirass})
27304 The Cuirass package to use.
27306 @item @code{workers} (default: @code{1})
27307 Start @var{workers} parallel workers.
27309 @item @code{server} (default: @code{#f})
27310 Do not use Avahi discovery and connect to the given @code{server} IP
27313 @item @code{systems} (default: @code{(list (%current-system))})
27314 Only request builds for the given @var{systems}.
27316 @item @code{log-file} (default: @code{"/var/log/cuirass-remote-worker.log"})
27317 Location of the log file.
27319 @item @code{publish-port} (default: @code{5558})
27320 The TCP port of the publish server. It defaults to @code{5558}.
27322 @item @code{public-key}
27323 @item @code{private-key}
27324 Use the specific @var{file}s as the public/private key pair used to sign
27325 the store items being published.
27330 @node Power Management Services
27331 @subsection Power Management Services
27334 @cindex power management with TLP
27335 @subsubheading TLP daemon
27337 The @code{(gnu services pm)} module provides a Guix service definition
27338 for the Linux power management tool TLP.
27340 TLP enables various powersaving modes in userspace and kernel.
27341 Contrary to @code{upower-service}, it is not a passive,
27342 monitoring tool, as it will apply custom settings each time a new power
27343 source is detected. More information can be found at
27344 @uref{https://linrunner.de/en/tlp/tlp.html, TLP home page}.
27346 @deffn {Scheme Variable} tlp-service-type
27347 The service type for the TLP tool. The default settings are optimised
27348 for battery life on most systems, but you can tweak them to your heart's
27349 content by adding a valid @code{tlp-configuration}:
27351 (service tlp-service-type
27353 (cpu-scaling-governor-on-ac (list "performance"))
27354 (sched-powersave-on-bat? #t)))
27358 Each parameter definition is preceded by its type; for example,
27359 @samp{boolean foo} indicates that the @code{foo} parameter
27360 should be specified as a boolean. Types starting with
27361 @code{maybe-} denote parameters that won't show up in TLP config file
27362 when their value is @code{'disabled}.
27364 @c The following documentation was initially generated by
27365 @c (generate-tlp-documentation) in (gnu services pm). Manually maintained
27366 @c documentation is better, so we shouldn't hesitate to edit below as
27367 @c needed. However if the change you want to make to this documentation
27368 @c can be done in an automated way, it's probably easier to change
27369 @c (generate-documentation) than to make it below and have to deal with
27370 @c the churn as TLP updates.
27372 Available @code{tlp-configuration} fields are:
27374 @deftypevr {@code{tlp-configuration} parameter} package tlp
27379 @deftypevr {@code{tlp-configuration} parameter} boolean tlp-enable?
27380 Set to true if you wish to enable TLP.
27382 Defaults to @samp{#t}.
27386 @deftypevr {@code{tlp-configuration} parameter} string tlp-default-mode
27387 Default mode when no power supply can be detected. Alternatives are AC
27390 Defaults to @samp{"AC"}.
27394 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-ac
27395 Number of seconds Linux kernel has to wait after the disk goes idle,
27396 before syncing on AC.
27398 Defaults to @samp{0}.
27402 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer disk-idle-secs-on-bat
27403 Same as @code{disk-idle-ac} but on BAT mode.
27405 Defaults to @samp{2}.
27409 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-ac
27410 Dirty pages flushing periodicity, expressed in seconds.
27412 Defaults to @samp{15}.
27416 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer max-lost-work-secs-on-bat
27417 Same as @code{max-lost-work-secs-on-ac} but on BAT mode.
27419 Defaults to @samp{60}.
27423 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-ac
27424 CPU frequency scaling governor on AC mode. With intel_pstate driver,
27425 alternatives are powersave and performance. With acpi-cpufreq driver,
27426 alternatives are ondemand, powersave, performance and conservative.
27428 Defaults to @samp{disabled}.
27432 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list cpu-scaling-governor-on-bat
27433 Same as @code{cpu-scaling-governor-on-ac} but on BAT mode.
27435 Defaults to @samp{disabled}.
27439 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-ac
27440 Set the min available frequency for the scaling governor on AC.
27442 Defaults to @samp{disabled}.
27446 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-ac
27447 Set the max available frequency for the scaling governor on AC.
27449 Defaults to @samp{disabled}.
27453 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-min-freq-on-bat
27454 Set the min available frequency for the scaling governor on BAT.
27456 Defaults to @samp{disabled}.
27460 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-scaling-max-freq-on-bat
27461 Set the max available frequency for the scaling governor on BAT.
27463 Defaults to @samp{disabled}.
27467 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-ac
27468 Limit the min P-state to control the power dissipation of the CPU, in AC
27469 mode. Values are stated as a percentage of the available performance.
27471 Defaults to @samp{disabled}.
27475 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-ac
27476 Limit the max P-state to control the power dissipation of the CPU, in AC
27477 mode. Values are stated as a percentage of the available performance.
27479 Defaults to @samp{disabled}.
27483 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-min-perf-on-bat
27484 Same as @code{cpu-min-perf-on-ac} on BAT mode.
27486 Defaults to @samp{disabled}.
27490 @deftypevr {@code{tlp-configuration} parameter} maybe-non-negative-integer cpu-max-perf-on-bat
27491 Same as @code{cpu-max-perf-on-ac} on BAT mode.
27493 Defaults to @samp{disabled}.
27497 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-ac?
27498 Enable CPU turbo boost feature on AC mode.
27500 Defaults to @samp{disabled}.
27504 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean cpu-boost-on-bat?
27505 Same as @code{cpu-boost-on-ac?} on BAT mode.
27507 Defaults to @samp{disabled}.
27511 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-ac?
27512 Allow Linux kernel to minimize the number of CPU cores/hyper-threads
27513 used under light load conditions.
27515 Defaults to @samp{#f}.
27519 @deftypevr {@code{tlp-configuration} parameter} boolean sched-powersave-on-bat?
27520 Same as @code{sched-powersave-on-ac?} but on BAT mode.
27522 Defaults to @samp{#t}.
27526 @deftypevr {@code{tlp-configuration} parameter} boolean nmi-watchdog?
27527 Enable Linux kernel NMI watchdog.
27529 Defaults to @samp{#f}.
27533 @deftypevr {@code{tlp-configuration} parameter} maybe-string phc-controls
27534 For Linux kernels with PHC patch applied, change CPU voltages. An
27535 example value would be @samp{"F:V F:V F:V F:V"}.
27537 Defaults to @samp{disabled}.
27541 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-ac
27542 Set CPU performance versus energy saving policy on AC@. Alternatives are
27543 performance, normal, powersave.
27545 Defaults to @samp{"performance"}.
27549 @deftypevr {@code{tlp-configuration} parameter} string energy-perf-policy-on-bat
27550 Same as @code{energy-perf-policy-ac} but on BAT mode.
27552 Defaults to @samp{"powersave"}.
27556 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disks-devices
27561 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-ac
27562 Hard disk advanced power management level.
27566 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list disk-apm-level-on-bat
27567 Same as @code{disk-apm-bat} but on BAT mode.
27571 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-ac
27572 Hard disk spin down timeout. One value has to be specified for each
27573 declared hard disk.
27575 Defaults to @samp{disabled}.
27579 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-spindown-timeout-on-bat
27580 Same as @code{disk-spindown-timeout-on-ac} but on BAT mode.
27582 Defaults to @samp{disabled}.
27586 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list disk-iosched
27587 Select IO scheduler for disk devices. One value has to be specified for
27588 each declared hard disk. Example alternatives are cfq, deadline and
27591 Defaults to @samp{disabled}.
27595 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-ac
27596 SATA aggressive link power management (ALPM) level. Alternatives are
27597 min_power, medium_power, max_performance.
27599 Defaults to @samp{"max_performance"}.
27603 @deftypevr {@code{tlp-configuration} parameter} string sata-linkpwr-on-bat
27604 Same as @code{sata-linkpwr-ac} but on BAT mode.
27606 Defaults to @samp{"min_power"}.
27610 @deftypevr {@code{tlp-configuration} parameter} maybe-string sata-linkpwr-blacklist
27611 Exclude specified SATA host devices for link power management.
27613 Defaults to @samp{disabled}.
27617 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-ac?
27618 Enable Runtime Power Management for AHCI controller and disks on AC
27621 Defaults to @samp{disabled}.
27625 @deftypevr {@code{tlp-configuration} parameter} maybe-on-off-boolean ahci-runtime-pm-on-bat?
27626 Same as @code{ahci-runtime-pm-on-ac} on BAT mode.
27628 Defaults to @samp{disabled}.
27632 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer ahci-runtime-pm-timeout
27633 Seconds of inactivity before disk is suspended.
27635 Defaults to @samp{15}.
27639 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-ac
27640 PCI Express Active State Power Management level. Alternatives are
27641 default, performance, powersave.
27643 Defaults to @samp{"performance"}.
27647 @deftypevr {@code{tlp-configuration} parameter} string pcie-aspm-on-bat
27648 Same as @code{pcie-aspm-ac} but on BAT mode.
27650 Defaults to @samp{"powersave"}.
27654 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-ac
27655 Radeon graphics clock speed level. Alternatives are low, mid, high,
27658 Defaults to @samp{"high"}.
27662 @deftypevr {@code{tlp-configuration} parameter} string radeon-power-profile-on-bat
27663 Same as @code{radeon-power-ac} but on BAT mode.
27665 Defaults to @samp{"low"}.
27669 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-ac
27670 Radeon dynamic power management method (DPM). Alternatives are battery,
27673 Defaults to @samp{"performance"}.
27677 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-state-on-bat
27678 Same as @code{radeon-dpm-state-ac} but on BAT mode.
27680 Defaults to @samp{"battery"}.
27684 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-ac
27685 Radeon DPM performance level. Alternatives are auto, low, high.
27687 Defaults to @samp{"auto"}.
27691 @deftypevr {@code{tlp-configuration} parameter} string radeon-dpm-perf-level-on-bat
27692 Same as @code{radeon-dpm-perf-ac} but on BAT mode.
27694 Defaults to @samp{"auto"}.
27698 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-ac?
27699 Wifi power saving mode.
27701 Defaults to @samp{#f}.
27705 @deftypevr {@code{tlp-configuration} parameter} on-off-boolean wifi-pwr-on-bat?
27706 Same as @code{wifi-power-ac?} but on BAT mode.
27708 Defaults to @samp{#t}.
27712 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean wol-disable?
27713 Disable wake on LAN.
27715 Defaults to @samp{#t}.
27719 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-ac
27720 Timeout duration in seconds before activating audio power saving on
27721 Intel HDA and AC97 devices. A value of 0 disables power saving.
27723 Defaults to @samp{0}.
27727 @deftypevr {@code{tlp-configuration} parameter} non-negative-integer sound-power-save-on-bat
27728 Same as @code{sound-powersave-ac} but on BAT mode.
27730 Defaults to @samp{1}.
27734 @deftypevr {@code{tlp-configuration} parameter} y-n-boolean sound-power-save-controller?
27735 Disable controller in powersaving mode on Intel HDA devices.
27737 Defaults to @samp{#t}.
27741 @deftypevr {@code{tlp-configuration} parameter} boolean bay-poweroff-on-bat?
27742 Enable optical drive in UltraBay/MediaBay on BAT mode. Drive can be
27743 powered on again by releasing (and reinserting) the eject lever or by
27744 pressing the disc eject button on newer models.
27746 Defaults to @samp{#f}.
27750 @deftypevr {@code{tlp-configuration} parameter} string bay-device
27751 Name of the optical drive device to power off.
27753 Defaults to @samp{"sr0"}.
27757 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-ac
27758 Runtime Power Management for PCI(e) bus devices. Alternatives are on
27761 Defaults to @samp{"on"}.
27765 @deftypevr {@code{tlp-configuration} parameter} string runtime-pm-on-bat
27766 Same as @code{runtime-pm-ac} but on BAT mode.
27768 Defaults to @samp{"auto"}.
27772 @deftypevr {@code{tlp-configuration} parameter} boolean runtime-pm-all?
27773 Runtime Power Management for all PCI(e) bus devices, except blacklisted
27776 Defaults to @samp{#t}.
27780 @deftypevr {@code{tlp-configuration} parameter} maybe-space-separated-string-list runtime-pm-blacklist
27781 Exclude specified PCI(e) device addresses from Runtime Power Management.
27783 Defaults to @samp{disabled}.
27787 @deftypevr {@code{tlp-configuration} parameter} space-separated-string-list runtime-pm-driver-blacklist
27788 Exclude PCI(e) devices assigned to the specified drivers from Runtime
27793 @deftypevr {@code{tlp-configuration} parameter} boolean usb-autosuspend?
27794 Enable USB autosuspend feature.
27796 Defaults to @samp{#t}.
27800 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-blacklist
27801 Exclude specified devices from USB autosuspend.
27803 Defaults to @samp{disabled}.
27807 @deftypevr {@code{tlp-configuration} parameter} boolean usb-blacklist-wwan?
27808 Exclude WWAN devices from USB autosuspend.
27810 Defaults to @samp{#t}.
27814 @deftypevr {@code{tlp-configuration} parameter} maybe-string usb-whitelist
27815 Include specified devices into USB autosuspend, even if they are already
27816 excluded by the driver or via @code{usb-blacklist-wwan?}.
27818 Defaults to @samp{disabled}.
27822 @deftypevr {@code{tlp-configuration} parameter} maybe-boolean usb-autosuspend-disable-on-shutdown?
27823 Enable USB autosuspend before shutdown.
27825 Defaults to @samp{disabled}.
27829 @deftypevr {@code{tlp-configuration} parameter} boolean restore-device-state-on-startup?
27830 Restore radio device state (bluetooth, wifi, wwan) from previous
27831 shutdown on system startup.
27833 Defaults to @samp{#f}.
27838 @cindex CPU frequency scaling with thermald
27839 @subsubheading Thermald daemon
27841 The @code{(gnu services pm)} module provides an interface to
27842 thermald, a CPU frequency scaling service which helps prevent overheating.
27844 @defvr {Scheme Variable} thermald-service-type
27845 This is the service type for
27846 @uref{https://01.org/linux-thermal-daemon/, thermald}, the Linux
27847 Thermal Daemon, which is responsible for controlling the thermal state
27848 of processors and preventing overheating.
27851 @deftp {Data Type} thermald-configuration
27852 Data type representing the configuration of @code{thermald-service-type}.
27855 @item @code{ignore-cpuid-check?} (default: @code{#f})
27856 Ignore cpuid check for supported CPU models.
27858 @item @code{thermald} (default: @var{thermald})
27859 Package object of thermald.
27864 @node Audio Services
27865 @subsection Audio Services
27867 The @code{(gnu services audio)} module provides a service to start MPD
27868 (the Music Player Daemon).
27871 @subsubheading Music Player Daemon
27873 The Music Player Daemon (MPD) is a service that can play music while
27874 being controlled from the local machine or over the network by a variety
27877 The following example shows how one might run @code{mpd} as user
27878 @code{"bob"} on port @code{6666}. It uses pulseaudio for output.
27881 (service mpd-service-type
27887 @defvr {Scheme Variable} mpd-service-type
27888 The service type for @command{mpd}
27891 @deftp {Data Type} mpd-configuration
27892 Data type representing the configuration of @command{mpd}.
27895 @item @code{user} (default: @code{"mpd"})
27896 The user to run mpd as.
27898 @item @code{music-dir} (default: @code{"~/Music"})
27899 The directory to scan for music files.
27901 @item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
27902 The directory to store playlists.
27904 @item @code{db-file} (default: @code{"~/.mpd/tag_cache"})
27905 The location of the music database.
27907 @item @code{state-file} (default: @code{"~/.mpd/state"})
27908 The location of the file that stores current MPD's state.
27910 @item @code{sticker-file} (default: @code{"~/.mpd/sticker.sql"})
27911 The location of the sticker database.
27913 @item @code{port} (default: @code{"6600"})
27914 The port to run mpd on.
27916 @item @code{address} (default: @code{"any"})
27917 The address that mpd will bind to. To use a Unix domain socket,
27918 an absolute path can be specified here.
27920 @item @code{outputs} (default: @code{"(list (mpd-output))"})
27921 The audio outputs that MPD can use. By default this is a single output using pulseaudio.
27926 @deftp {Data Type} mpd-output
27927 Data type representing an @command{mpd} audio output.
27930 @item @code{name} (default: @code{"MPD"})
27931 The name of the audio output.
27933 @item @code{type} (default: @code{"pulse"})
27934 The type of audio output.
27936 @item @code{enabled?} (default: @code{#t})
27937 Specifies whether this audio output is enabled when MPD is started. By
27938 default, all audio outputs are enabled. This is just the default
27939 setting when there is no state file; with a state file, the previous
27942 @item @code{tags?} (default: @code{#t})
27943 If set to @code{#f}, then MPD will not send tags to this output. This
27944 is only useful for output plugins that can receive tags, for example the
27945 @code{httpd} output plugin.
27947 @item @code{always-on?} (default: @code{#f})
27948 If set to @code{#t}, then MPD attempts to keep this audio output always
27949 open. This may be useful for streaming servers, when you don’t want to
27950 disconnect all listeners even when playback is accidentally stopped.
27952 @item @code{mixer-type}
27953 This field accepts a symbol that specifies which mixer should be used
27954 for this audio output: the @code{hardware} mixer, the @code{software}
27955 mixer, the @code{null} mixer (allows setting the volume, but with no
27956 effect; this can be used as a trick to implement an external mixer
27957 External Mixer) or no mixer (@code{none}).
27959 @item @code{extra-options} (default: @code{'()})
27960 An association list of option symbols to string values to be appended to
27961 the audio output configuration.
27966 The following example shows a configuration of @code{mpd} that provides
27967 an HTTP audio streaming output.
27970 (service mpd-service-type
27978 `((encoder . "vorbis")
27979 (port . "8080"))))))))
27983 @node Virtualization Services
27984 @subsection Virtualization Services
27986 The @code{(gnu services virtualization)} module provides services for
27987 the libvirt and virtlog daemons, as well as other virtualization-related
27990 @subsubheading Libvirt daemon
27992 @code{libvirtd} is the server side daemon component of the libvirt
27993 virtualization management system. This daemon runs on host servers
27994 and performs required management tasks for virtualized guests.
27996 @deffn {Scheme Variable} libvirt-service-type
27997 This is the type of the @uref{https://libvirt.org, libvirt daemon}.
27998 Its value must be a @code{libvirt-configuration}.
28001 (service libvirt-service-type
28002 (libvirt-configuration
28003 (unix-sock-group "libvirt")
28004 (tls-port "16555")))
28008 @c Auto-generated with (generate-libvirt-documentation)
28009 Available @code{libvirt-configuration} fields are:
28011 @deftypevr {@code{libvirt-configuration} parameter} package libvirt
28016 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tls?
28017 Flag listening for secure TLS connections on the public TCP/IP port.
28018 You must set @code{listen} for this to have any effect.
28020 It is necessary to setup a CA and issue server certificates before using
28023 Defaults to @samp{#t}.
28027 @deftypevr {@code{libvirt-configuration} parameter} boolean listen-tcp?
28028 Listen for unencrypted TCP connections on the public TCP/IP port. You must
28029 set @code{listen} for this to have any effect.
28031 Using the TCP socket requires SASL authentication by default. Only SASL
28032 mechanisms which support data encryption are allowed. This is
28033 DIGEST_MD5 and GSSAPI (Kerberos5).
28035 Defaults to @samp{#f}.
28039 @deftypevr {@code{libvirt-configuration} parameter} string tls-port
28040 Port for accepting secure TLS connections. This can be a port number,
28043 Defaults to @samp{"16514"}.
28047 @deftypevr {@code{libvirt-configuration} parameter} string tcp-port
28048 Port for accepting insecure TCP connections. This can be a port number,
28051 Defaults to @samp{"16509"}.
28055 @deftypevr {@code{libvirt-configuration} parameter} string listen-addr
28056 IP address or hostname used for client connections.
28058 Defaults to @samp{"0.0.0.0"}.
28062 @deftypevr {@code{libvirt-configuration} parameter} boolean mdns-adv?
28063 Flag toggling mDNS advertisement of the libvirt service.
28065 Alternatively can disable for all services on a host by stopping the
28068 Defaults to @samp{#f}.
28072 @deftypevr {@code{libvirt-configuration} parameter} string mdns-name
28073 Default mDNS advertisement name. This must be unique on the immediate
28076 Defaults to @samp{"Virtualization Host <hostname>"}.
28080 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-group
28081 UNIX domain socket group ownership. This can be used to allow a
28082 'trusted' set of users access to management capabilities without
28085 Defaults to @samp{"root"}.
28089 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-ro-perms
28090 UNIX socket permissions for the R/O socket. This is used for monitoring
28093 Defaults to @samp{"0777"}.
28097 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-rw-perms
28098 UNIX socket permissions for the R/W socket. Default allows only root.
28099 If PolicyKit is enabled on the socket, the default will change to allow
28100 everyone (eg, 0777)
28102 Defaults to @samp{"0770"}.
28106 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-admin-perms
28107 UNIX socket permissions for the admin socket. Default allows only owner
28108 (root), do not change it unless you are sure to whom you are exposing
28111 Defaults to @samp{"0777"}.
28115 @deftypevr {@code{libvirt-configuration} parameter} string unix-sock-dir
28116 The directory in which sockets will be found/created.
28118 Defaults to @samp{"/var/run/libvirt"}.
28122 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-ro
28123 Authentication scheme for UNIX read-only sockets. By default socket
28124 permissions allow anyone to connect
28126 Defaults to @samp{"polkit"}.
28130 @deftypevr {@code{libvirt-configuration} parameter} string auth-unix-rw
28131 Authentication scheme for UNIX read-write sockets. By default socket
28132 permissions only allow root. If PolicyKit support was compiled into
28133 libvirt, the default will be to use 'polkit' auth.
28135 Defaults to @samp{"polkit"}.
28139 @deftypevr {@code{libvirt-configuration} parameter} string auth-tcp
28140 Authentication scheme for TCP sockets. If you don't enable SASL, then
28141 all TCP traffic is cleartext. Don't do this outside of a dev/test
28144 Defaults to @samp{"sasl"}.
28148 @deftypevr {@code{libvirt-configuration} parameter} string auth-tls
28149 Authentication scheme for TLS sockets. TLS sockets already have
28150 encryption provided by the TLS layer, and limited authentication is done
28153 It is possible to make use of any SASL authentication mechanism as well,
28154 by using 'sasl' for this option
28156 Defaults to @samp{"none"}.
28160 @deftypevr {@code{libvirt-configuration} parameter} optional-list access-drivers
28161 API access control scheme.
28163 By default an authenticated user is allowed access to all APIs. Access
28164 drivers can place restrictions on this.
28166 Defaults to @samp{()}.
28170 @deftypevr {@code{libvirt-configuration} parameter} string key-file
28171 Server key file path. If set to an empty string, then no private key is
28174 Defaults to @samp{""}.
28178 @deftypevr {@code{libvirt-configuration} parameter} string cert-file
28179 Server key file path. If set to an empty string, then no certificate is
28182 Defaults to @samp{""}.
28186 @deftypevr {@code{libvirt-configuration} parameter} string ca-file
28187 Server key file path. If set to an empty string, then no CA certificate
28190 Defaults to @samp{""}.
28194 @deftypevr {@code{libvirt-configuration} parameter} string crl-file
28195 Certificate revocation list path. If set to an empty string, then no
28198 Defaults to @samp{""}.
28202 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-sanity-cert
28203 Disable verification of our own server certificates.
28205 When libvirtd starts it performs some sanity checks against its own
28208 Defaults to @samp{#f}.
28212 @deftypevr {@code{libvirt-configuration} parameter} boolean tls-no-verify-cert
28213 Disable verification of client certificates.
28215 Client certificate verification is the primary authentication mechanism.
28216 Any client which does not present a certificate signed by the CA will be
28219 Defaults to @samp{#f}.
28223 @deftypevr {@code{libvirt-configuration} parameter} optional-list tls-allowed-dn-list
28224 Whitelist of allowed x509 Distinguished Name.
28226 Defaults to @samp{()}.
28230 @deftypevr {@code{libvirt-configuration} parameter} optional-list sasl-allowed-usernames
28231 Whitelist of allowed SASL usernames. The format for username depends on
28232 the SASL authentication mechanism.
28234 Defaults to @samp{()}.
28238 @deftypevr {@code{libvirt-configuration} parameter} string tls-priority
28239 Override the compile time default TLS priority string. The default is
28240 usually @samp{"NORMAL"} unless overridden at build time. Only set this is it
28241 is desired for libvirt to deviate from the global default settings.
28243 Defaults to @samp{"NORMAL"}.
28247 @deftypevr {@code{libvirt-configuration} parameter} integer max-clients
28248 Maximum number of concurrent client connections to allow over all
28251 Defaults to @samp{5000}.
28255 @deftypevr {@code{libvirt-configuration} parameter} integer max-queued-clients
28256 Maximum length of queue of connections waiting to be accepted by the
28257 daemon. Note, that some protocols supporting retransmission may obey
28258 this so that a later reattempt at connection succeeds.
28260 Defaults to @samp{1000}.
28264 @deftypevr {@code{libvirt-configuration} parameter} integer max-anonymous-clients
28265 Maximum length of queue of accepted but not yet authenticated clients.
28266 Set this to zero to turn this feature off
28268 Defaults to @samp{20}.
28272 @deftypevr {@code{libvirt-configuration} parameter} integer min-workers
28273 Number of workers to start up initially.
28275 Defaults to @samp{5}.
28279 @deftypevr {@code{libvirt-configuration} parameter} integer max-workers
28280 Maximum number of worker threads.
28282 If the number of active clients exceeds @code{min-workers}, then more
28283 threads are spawned, up to max_workers limit. Typically you'd want
28284 max_workers to equal maximum number of clients allowed.
28286 Defaults to @samp{20}.
28290 @deftypevr {@code{libvirt-configuration} parameter} integer prio-workers
28291 Number of priority workers. If all workers from above pool are stuck,
28292 some calls marked as high priority (notably domainDestroy) can be
28293 executed in this pool.
28295 Defaults to @samp{5}.
28299 @deftypevr {@code{libvirt-configuration} parameter} integer max-requests
28300 Total global limit on concurrent RPC calls.
28302 Defaults to @samp{20}.
28306 @deftypevr {@code{libvirt-configuration} parameter} integer max-client-requests
28307 Limit on concurrent requests from a single client connection. To avoid
28308 one client monopolizing the server this should be a small fraction of
28309 the global max_requests and max_workers parameter.
28311 Defaults to @samp{5}.
28315 @deftypevr {@code{libvirt-configuration} parameter} integer admin-min-workers
28316 Same as @code{min-workers} but for the admin interface.
28318 Defaults to @samp{1}.
28322 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-workers
28323 Same as @code{max-workers} but for the admin interface.
28325 Defaults to @samp{5}.
28329 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-clients
28330 Same as @code{max-clients} but for the admin interface.
28332 Defaults to @samp{5}.
28336 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-queued-clients
28337 Same as @code{max-queued-clients} but for the admin interface.
28339 Defaults to @samp{5}.
28343 @deftypevr {@code{libvirt-configuration} parameter} integer admin-max-client-requests
28344 Same as @code{max-client-requests} but for the admin interface.
28346 Defaults to @samp{5}.
28350 @deftypevr {@code{libvirt-configuration} parameter} integer log-level
28351 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
28353 Defaults to @samp{3}.
28357 @deftypevr {@code{libvirt-configuration} parameter} string log-filters
28360 A filter allows to select a different logging level for a given category
28361 of logs. The format for a filter is one of:
28372 where @code{name} is a string which is matched against the category
28373 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
28374 file, e.g., @samp{"remote"}, @samp{"qemu"}, or @samp{"util.json"} (the
28375 name in the filter can be a substring of the full category name, in
28376 order to match multiple similar categories), the optional @samp{"+"}
28377 prefix tells libvirt to log stack trace for each message matching name,
28378 and @code{x} is the minimal level where matching messages should be
28396 Multiple filters can be defined in a single filters statement, they just
28397 need to be separated by spaces.
28399 Defaults to @samp{"3:remote 4:event"}.
28403 @deftypevr {@code{libvirt-configuration} parameter} string log-outputs
28406 An output is one of the places to save logging information. The format
28407 for an output can be:
28411 output goes to stderr
28413 @item x:syslog:name
28414 use syslog for the output and use the given name as the ident
28416 @item x:file:file_path
28417 output to a file, with the given filepath
28420 output to journald logging system
28424 In all case the x prefix is the minimal level, acting as a filter
28441 Multiple outputs can be defined, they just need to be separated by
28444 Defaults to @samp{"3:stderr"}.
28448 @deftypevr {@code{libvirt-configuration} parameter} integer audit-level
28449 Allows usage of the auditing subsystem to be altered
28453 0: disable all auditing
28456 1: enable auditing, only if enabled on host
28459 2: enable auditing, and exit if disabled on host.
28463 Defaults to @samp{1}.
28467 @deftypevr {@code{libvirt-configuration} parameter} boolean audit-logging
28468 Send audit messages via libvirt logging infrastructure.
28470 Defaults to @samp{#f}.
28474 @deftypevr {@code{libvirt-configuration} parameter} optional-string host-uuid
28475 Host UUID@. UUID must not have all digits be the same.
28477 Defaults to @samp{""}.
28481 @deftypevr {@code{libvirt-configuration} parameter} string host-uuid-source
28482 Source to read host UUID.
28486 @code{smbios}: fetch the UUID from @code{dmidecode -s system-uuid}
28489 @code{machine-id}: fetch the UUID from @code{/etc/machine-id}
28493 If @code{dmidecode} does not provide a valid UUID a temporary UUID will
28496 Defaults to @samp{"smbios"}.
28500 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-interval
28501 A keepalive message is sent to a client after @code{keepalive_interval}
28502 seconds of inactivity to check if the client is still responding. If
28503 set to -1, libvirtd will never send keepalive requests; however clients
28504 can still send them and the daemon will send responses.
28506 Defaults to @samp{5}.
28510 @deftypevr {@code{libvirt-configuration} parameter} integer keepalive-count
28511 Maximum number of keepalive messages that are allowed to be sent to the
28512 client without getting any response before the connection is considered
28515 In other words, the connection is automatically closed approximately
28516 after @code{keepalive_interval * (keepalive_count + 1)} seconds since
28517 the last message received from the client. When @code{keepalive-count}
28518 is set to 0, connections will be automatically closed after
28519 @code{keepalive-interval} seconds of inactivity without sending any
28520 keepalive messages.
28522 Defaults to @samp{5}.
28526 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-interval
28527 Same as above but for admin interface.
28529 Defaults to @samp{5}.
28533 @deftypevr {@code{libvirt-configuration} parameter} integer admin-keepalive-count
28534 Same as above but for admin interface.
28536 Defaults to @samp{5}.
28540 @deftypevr {@code{libvirt-configuration} parameter} integer ovs-timeout
28541 Timeout for Open vSwitch calls.
28543 The @code{ovs-vsctl} utility is used for the configuration and its
28544 timeout option is set by default to 5 seconds to avoid potential
28545 infinite waits blocking libvirt.
28547 Defaults to @samp{5}.
28551 @c %end of autogenerated docs
28553 @subsubheading Virtlog daemon
28554 The virtlogd service is a server side daemon component of libvirt that is
28555 used to manage logs from virtual machine consoles.
28557 This daemon is not used directly by libvirt client applications, rather it
28558 is called on their behalf by @code{libvirtd}. By maintaining the logs in a
28559 standalone daemon, the main @code{libvirtd} daemon can be restarted without
28560 risk of losing logs. The @code{virtlogd} daemon has the ability to re-exec()
28561 itself upon receiving @code{SIGUSR1}, to allow live upgrades without downtime.
28563 @deffn {Scheme Variable} virtlog-service-type
28564 This is the type of the virtlog daemon.
28565 Its value must be a @code{virtlog-configuration}.
28568 (service virtlog-service-type
28569 (virtlog-configuration
28570 (max-clients 1000)))
28574 @deftypevr {@code{virtlog-configuration} parameter} integer log-level
28575 Logging level. 4 errors, 3 warnings, 2 information, 1 debug.
28577 Defaults to @samp{3}.
28581 @deftypevr {@code{virtlog-configuration} parameter} string log-filters
28584 A filter allows to select a different logging level for a given category
28585 of logs The format for a filter is one of:
28596 where @code{name} is a string which is matched against the category
28597 given in the @code{VIR_LOG_INIT()} at the top of each libvirt source
28598 file, e.g., "remote", "qemu", or "util.json" (the name in the filter can
28599 be a substring of the full category name, in order to match multiple
28600 similar categories), the optional "+" prefix tells libvirt to log stack
28601 trace for each message matching name, and @code{x} is the minimal level
28602 where matching messages should be logged:
28619 Multiple filters can be defined in a single filters statement, they just
28620 need to be separated by spaces.
28622 Defaults to @samp{"3:remote 4:event"}.
28626 @deftypevr {@code{virtlog-configuration} parameter} string log-outputs
28629 An output is one of the places to save logging information The format
28630 for an output can be:
28634 output goes to stderr
28636 @item x:syslog:name
28637 use syslog for the output and use the given name as the ident
28639 @item x:file:file_path
28640 output to a file, with the given filepath
28643 output to journald logging system
28647 In all case the x prefix is the minimal level, acting as a filter
28664 Multiple outputs can be defined, they just need to be separated by
28667 Defaults to @samp{"3:stderr"}.
28671 @deftypevr {@code{virtlog-configuration} parameter} integer max-clients
28672 Maximum number of concurrent client connections to allow over all
28675 Defaults to @samp{1024}.
28679 @deftypevr {@code{virtlog-configuration} parameter} integer max-size
28680 Maximum file size before rolling over.
28682 Defaults to @samp{2MB}
28686 @deftypevr {@code{virtlog-configuration} parameter} integer max-backups
28687 Maximum number of backup files to keep.
28689 Defaults to @samp{3}
28693 @anchor{transparent-emulation-qemu}
28694 @subsubheading Transparent Emulation with QEMU
28697 @cindex @code{binfmt_misc}
28698 @code{qemu-binfmt-service-type} provides support for transparent
28699 emulation of program binaries built for different architectures---e.g.,
28700 it allows you to transparently execute an ARMv7 program on an x86_64
28701 machine. It achieves this by combining the @uref{https://www.qemu.org,
28702 QEMU} emulator and the @code{binfmt_misc} feature of the kernel Linux.
28703 This feature only allows you to emulate GNU/Linux on a different
28704 architecture, but see below for GNU/Hurd support.
28706 @defvr {Scheme Variable} qemu-binfmt-service-type
28707 This is the type of the QEMU/binfmt service for transparent emulation.
28708 Its value must be a @code{qemu-binfmt-configuration} object, which
28709 specifies the QEMU package to use as well as the architecture we want to
28713 (service qemu-binfmt-service-type
28714 (qemu-binfmt-configuration
28715 (platforms (lookup-qemu-platforms "arm" "aarch64"))))
28718 In this example, we enable transparent emulation for the ARM and aarch64
28719 platforms. Running @code{herd stop qemu-binfmt} turns it off, and
28720 running @code{herd start qemu-binfmt} turns it back on (@pxref{Invoking
28721 herd, the @command{herd} command,, shepherd, The GNU Shepherd Manual}).
28724 @deftp {Data Type} qemu-binfmt-configuration
28725 This is the configuration for the @code{qemu-binfmt} service.
28728 @item @code{platforms} (default: @code{'()})
28729 The list of emulated QEMU platforms. Each item must be a @dfn{platform
28730 object} as returned by @code{lookup-qemu-platforms} (see below).
28732 For example, let's suppose you're on an x86_64 machine and you have this
28736 (service qemu-binfmt-service-type
28737 (qemu-binfmt-configuration
28738 (platforms (lookup-qemu-platforms "arm"))))
28744 guix build -s armhf-linux inkscape
28748 and it will build Inkscape for ARMv7 @emph{as if it were a native
28749 build}, transparently using QEMU to emulate the ARMv7 CPU@. Pretty handy
28750 if you'd like to test a package build for an architecture you don't have
28753 @item @code{qemu} (default: @code{qemu})
28754 The QEMU package to use.
28758 @deffn {Scheme Procedure} lookup-qemu-platforms @var{platforms}@dots{}
28759 Return the list of QEMU platform objects corresponding to
28760 @var{platforms}@dots{}. @var{platforms} must be a list of strings
28761 corresponding to platform names, such as @code{"arm"}, @code{"sparc"},
28762 @code{"mips64el"}, and so on.
28765 @deffn {Scheme Procedure} qemu-platform? @var{obj}
28766 Return true if @var{obj} is a platform object.
28769 @deffn {Scheme Procedure} qemu-platform-name @var{platform}
28770 Return the name of @var{platform}---a string such as @code{"arm"}.
28774 @subsubheading The Hurd in a Virtual Machine
28776 @cindex @code{hurd}
28780 Service @code{hurd-vm} provides support for running GNU/Hurd in a
28781 virtual machine (VM), a so-called @dfn{childhurd}. This service is meant
28782 to be used on GNU/Linux and the given GNU/Hurd operating system
28783 configuration is cross-compiled. The virtual machine is a Shepherd
28784 service that can be referred to by the names @code{hurd-vm} and
28785 @code{childhurd} and be controlled with commands such as:
28789 herd stop childhurd
28792 When the service is running, you can view its console by connecting to
28793 it with a VNC client, for example with:
28796 guix environment --ad-hoc tigervnc-client -- \
28797 vncviewer localhost:5900
28800 The default configuration (see @code{hurd-vm-configuration} below)
28801 spawns a secure shell (SSH) server in your GNU/Hurd system, which QEMU
28802 (the virtual machine emulator) redirects to port 10222 on the host.
28803 Thus, you can connect over SSH to the childhurd with:
28806 ssh root@@localhost -p 10022
28809 The childhurd is volatile and stateless: it starts with a fresh root
28810 file system every time you restart it. By default though, all the files
28811 under @file{/etc/childhurd} on the host are copied as is to the root
28812 file system of the childhurd when it boots. This allows you to
28813 initialize ``secrets'' inside the VM: SSH host keys, authorized
28814 substitute keys, and so on---see the explanation of @code{secret-root}
28817 @defvr {Scheme Variable} hurd-vm-service-type
28818 This is the type of the Hurd in a Virtual Machine service. Its value
28819 must be a @code{hurd-vm-configuration} object, which specifies the
28820 operating system (@pxref{operating-system Reference}) and the disk size
28821 for the Hurd Virtual Machine, the QEMU package to use as well as the
28822 options for running it.
28827 (service hurd-vm-service-type
28828 (hurd-vm-configuration
28829 (disk-size (* 5000 (expt 2 20))) ;5G
28830 (memory-size 1024))) ;1024MiB
28833 would create a disk image big enough to build GNU@tie{}Hello, with some
28837 @deftp {Data Type} hurd-vm-configuration
28838 The data type representing the configuration for
28839 @code{hurd-vm-service-type}.
28842 @item @code{os} (default: @var{%hurd-vm-operating-system})
28843 The operating system to instantiate. This default is bare-bones with a
28844 permissive OpenSSH secure shell daemon listening on port 2222
28845 (@pxref{Networking Services, @code{openssh-service-type}}).
28847 @item @code{qemu} (default: @code{qemu-minimal})
28848 The QEMU package to use.
28850 @item @code{image} (default: @var{hurd-vm-disk-image})
28851 The procedure used to build the disk-image built from this
28854 @item @code{disk-size} (default: @code{'guess})
28855 The size of the disk image.
28857 @item @code{memory-size} (default: @code{512})
28858 The memory size of the Virtual Machine in mebibytes.
28860 @item @code{options} (default: @code{'("--snapshot")})
28861 The extra options for running QEMU.
28863 @item @code{id} (default: @code{#f})
28864 If set, a non-zero positive integer used to parameterize Childhurd
28865 instances. It is appended to the service's name,
28866 e.g. @code{childhurd1}.
28868 @item @code{net-options} (default: @var{hurd-vm-net-options})
28869 The procedure used to produce the list of QEMU networking options.
28871 By default, it produces
28874 '("--device" "rtl8139,netdev=net0"
28875 "--netdev" "user,id=net0\
28876 ,hostfwd=tcp:127.0.0.1:@var{secrets-port}-:1004\
28877 ,hostfwd=tcp:127.0.0.1:@var{ssh-port}-:2222\
28878 ,hostfwd=tcp:127.0.0.1:@var{vnc-port}-:5900")
28881 with forwarded ports:
28884 @var{secrets-port}: @code{(+ 11004 (* 1000 @var{ID}))}
28885 @var{ssh-port}: @code{(+ 10022 (* 1000 @var{ID}))}
28886 @var{vnc-port}: @code{(+ 15900 (* 1000 @var{ID}))}
28889 @item @code{secret-root} (default: @file{/etc/childhurd})
28890 The root directory with out-of-band secrets to be installed into the
28891 childhurd once it runs. Childhurds are volatile which means that on
28892 every startup, secrets such as the SSH host keys and Guix signing key
28895 If the @file{/etc/childhurd} directory does not exist, the
28896 @code{secret-service} running in the Childhurd will be sent an empty
28899 By default, the service automatically populates @file{/etc/childhurd}
28900 with the following non-volatile secrets, unless they already exist:
28903 /etc/childhurd/etc/guix/acl
28904 /etc/childhurd/etc/guix/signing-key.pub
28905 /etc/childhurd/etc/guix/signing-key.sec
28906 /etc/childhurd/etc/ssh/ssh_host_ed25519_key
28907 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key
28908 /etc/childhurd/etc/ssh/ssh_host_ed25519_key.pub
28909 /etc/childhurd/etc/ssh/ssh_host_ecdsa_key.pub
28912 These files are automatically sent to the guest Hurd VM when it boots,
28913 including permissions.
28915 @cindex childhurd, offloading
28916 @cindex Hurd, offloading
28917 Having these files in place means that only a couple of things are
28918 missing to allow the host to offload @code{i586-gnu} builds to the
28923 Authorizing the childhurd's key on the host so that the host accepts
28924 build results coming from the childhurd, which can be done like so:
28927 guix archive --authorize < \
28928 /etc/childhurd/etc/guix/signing-key.pub
28932 Adding the childhurd to @file{/etc/guix/machines.scm} (@pxref{Daemon
28936 We're working towards making that happen automatically---get in touch
28937 with us at @email{guix-devel@@gnu.org} to discuss it!
28941 Note that by default the VM image is volatile, i.e., once stopped the
28942 contents are lost. If you want a stateful image instead, override the
28943 configuration's @code{image} and @code{options} without
28944 the @code{--snapshot} flag using something along these lines:
28947 (service hurd-vm-service-type
28948 (hurd-vm-configuration
28949 (image (const "/out/of/store/writable/hurd.img"))
28953 @subsubheading Ganeti
28958 This service is considered experimental. Configuration options may be changed
28959 in a backwards-incompatible manner, and not all features have been thorougly
28960 tested. Users of this service are encouraged to share their experience at
28961 @email{guix-devel@@gnu.org}.
28964 Ganeti is a virtual machine management system. It is designed to keep virtual
28965 machines running on a cluster of servers even in the event of hardware failures,
28966 and to make maintenance and recovery tasks easy. It consists of multiple
28967 services which are described later in this section. In addition to the Ganeti
28968 service, you will need the OpenSSH service (@pxref{Networking Services,
28969 @code{openssh-service-type}}), and update the @file{/etc/hosts} file
28970 (@pxref{operating-system Reference, @code{hosts-file}}) with the cluster name
28971 and address (or use a DNS server).
28973 All nodes participating in a Ganeti cluster should have the same Ganeti and
28974 @file{/etc/hosts} configuration. Here is an example configuration for a Ganeti
28975 cluster node that supports multiple storage backends, and installs the
28976 @code{debootstrap} and @code{guix} @dfn{OS providers}:
28979 (use-package-modules virtualization)
28980 (use-service-modules base ganeti networking ssh)
28983 (host-name "node1")
28984 (hosts-file (plain-file "hosts" (format #f "
28985 127.0.0.1 localhost
28988 192.168.1.200 ganeti.example.com
28989 192.168.1.201 node1.example.com node1
28990 192.168.1.202 node2.example.com node2
28993 ;; Install QEMU so we can use KVM-based instances, and LVM, DRBD and Ceph
28994 ;; in order to use the "plain", "drbd" and "rbd" storage backends.
28995 (packages (append (map specification->package
28996 '("qemu" "lvm2" "drbd-utils" "ceph"
28997 ;; Add the debootstrap and guix OS providers.
28998 "ganeti-instance-guix" "ganeti-instance-debootstrap"))
29001 (append (list (static-networking-service "eth0" "192.168.1.201"
29002 #:netmask "255.255.255.0"
29003 #:gateway "192.168.1.254"
29004 #:name-servers '("192.168.1.252"
29007 ;; Ganeti uses SSH to communicate between nodes.
29008 (service openssh-service-type
29009 (openssh-configuration
29010 (permit-root-login 'without-password)))
29012 (service ganeti-service-type
29013 (ganeti-configuration
29014 ;; This list specifies allowed file system paths
29015 ;; for storing virtual machine images.
29016 (file-storage-paths '("/srv/ganeti/file-storage"))
29017 ;; This variable configures a single "variant" for
29018 ;; both Debootstrap and Guix that works with KVM.
29019 (os %default-ganeti-os))))
29023 Users are advised to read the
29024 @url{http://docs.ganeti.org/ganeti/master/html/admin.html,Ganeti
29025 administrators guide} to learn about the various cluster options and
29026 day-to-day operations. There is also a
29027 @url{https://guix.gnu.org/blog/2020/running-a-ganeti-cluster-on-guix/,blog post}
29028 describing how to configure and initialize a small cluster.
29030 @defvr {Scheme Variable} ganeti-service-type
29031 This is a service type that includes all the various services that Ganeti
29034 Its value is a @code{ganeti-configuration} object that defines the package
29035 to use for CLI operations, as well as configuration for the various daemons.
29036 Allowed file storage paths and available guest operating systems are also
29037 configured through this data type.
29040 @deftp {Data Type} ganeti-configuration
29041 The @code{ganeti} service takes the following configuration options:
29044 @item @code{ganeti} (default: @code{ganeti})
29045 The @code{ganeti} package to use. It will be installed to the system profile
29046 and make @command{gnt-cluster}, @command{gnt-instance}, etc available. Note
29047 that the value specified here does not affect the other services as each refer
29048 to a specific @code{ganeti} package (see below).
29050 @item @code{noded-configuration} (default: @code{(ganeti-noded-configuration)})
29051 @itemx @code{confd-configuration} (default: @code{(ganeti-confd-configuration)})
29052 @itemx @code{wconfd-configuration} (default: @code{(ganeti-wconfd-configuration)})
29053 @itemx @code{luxid-configuration} (default: @code{(ganeti-luxid-configuration)})
29054 @itemx @code{rapi-configuration} (default: @code{(ganeti-rapi-configuration)})
29055 @itemx @code{kvmd-configuration} (default: @code{(ganeti-kvmd-configuration)})
29056 @itemx @code{mond-configuration} (default: @code{(ganeti-mond-configuration)})
29057 @itemx @code{metad-configuration} (default: @code{(ganeti-metad-configuration)})
29058 @itemx @code{watcher-configuration} (default: @code{(ganeti-watcher-configuration)})
29059 @itemx @code{cleaner-configuration} (default: @code{(ganeti-cleaner-configuration)})
29061 These options control the various daemons and cron jobs that are distributed
29062 with Ganeti. The possible values for these are described in detail below.
29063 To override a setting, you must use the configuration type for that service:
29066 (service ganeti-service-type
29067 (ganeti-configuration
29068 (rapi-configuration
29069 (ganeti-rapi-configuration
29070 (interface "eth1"))))
29071 (watcher-configuration
29072 (ganeti-watcher-configuration
29073 (rapi-ip "10.0.0.1"))))
29076 @item @code{file-storage-paths} (default: @code{'()})
29077 List of allowed directories for file storage backend.
29079 @item @code{os} (default: @code{%default-ganeti-os})
29080 List of @code{<ganeti-os>} records.
29083 In essence @code{ganeti-service-type} is shorthand for declaring each service
29087 (service ganeti-noded-service-type)
29088 (service ganeti-confd-service-type)
29089 (service ganeti-wconfd-service-type)
29090 (service ganeti-luxid-service-type)
29091 (service ganeti-kvmd-service-type)
29092 (service ganeti-mond-service-type)
29093 (service ganeti-metad-service-type)
29094 (service ganeti-watcher-service-type)
29095 (service ganeti-cleaner-service-type)
29098 Plus a service extension for @code{etc-service-type} that configures the file
29099 storage backend and OS variants.
29103 @deftp {Data Type} ganeti-os
29104 This data type is suitable for passing to the @code{os} parameter of
29105 @code{ganeti-configuration}. It takes the following parameters:
29109 The name for this OS provider. It is only used to specify where the
29110 configuration ends up. Setting it to ``debootstrap'' will create
29111 @file{/etc/ganeti/instance-debootstrap}.
29113 @item @code{extension}
29114 The file extension for variants of this OS type. For example
29115 @file{.conf} or @file{.scm}.
29117 @item @code{variants} (default: @code{'()})
29118 List of @code{ganeti-os-variant} objects for this OS.
29123 @deftp {Data Type} ganeti-os-variant
29124 This is the data type for a Ganeti OS variant. It takes the following
29129 The name of this variant.
29131 @item @code{configuration}
29132 A configuration file for this variant.
29136 @defvr {Scheme Variable} %default-debootstrap-hooks
29137 This variable contains hooks to configure networking and the GRUB bootloader.
29140 @defvr {Scheme Variable} %default-debootstrap-extra-pkgs
29141 This variable contains a list of packages suitable for a fully-virtualized guest.
29144 @deftp {Data Type} debootstrap-configuration
29146 This data type creates configuration files suitable for the debootstrap OS provider.
29149 @item @code{hooks} (default: @code{%default-debootstrap-hooks})
29150 When not @code{#f}, this must be a G-expression that specifies a directory with
29151 scripts that will run when the OS is installed. It can also be a list of
29152 @code{(name . file-like)} pairs. For example:
29155 `((99-hello-world . ,(plain-file "#!/bin/sh\necho Hello, World")))
29158 That will create a directory with one executable named @code{99-hello-world}
29159 and run it every time this variant is installed. If set to @code{#f}, hooks
29160 in @file{/etc/ganeti/instance-debootstrap/hooks} will be used, if any.
29161 @item @code{proxy} (default: @code{#f})
29162 Optional HTTP proxy to use.
29163 @item @code{mirror} (default: @code{#f})
29164 The Debian mirror. Typically something like @code{http://ftp.no.debian.org/debian}.
29165 The default varies depending on the distribution.
29166 @item @code{arch} (default: @code{#f})
29167 The dpkg architecture. Set to @code{armhf} to debootstrap an ARMv7 instance
29168 on an AArch64 host. Default is to use the current system architecture.
29169 @item @code{suite} (default: @code{"stable"})
29170 When set, this must be a Debian distribution ``suite'' such as @code{buster}
29171 or @code{focal}. If set to @code{#f}, the default for the OS provider is used.
29172 @item @code{extra-pkgs} (default: @code{%default-debootstrap-extra-pkgs})
29173 List of extra packages that will get installed by dpkg in addition
29174 to the minimal system.
29175 @item @code{components} (default: @code{#f})
29176 When set, must be a list of Debian repository ``components''. For example
29177 @code{'("main" "contrib")}.
29178 @item @code{generate-cache?} (default: @code{#t})
29179 Whether to automatically cache the generated debootstrap archive.
29180 @item @code{clean-cache} (default: @code{14})
29181 Discard the cache after this amount of days. Use @code{#f} to never
29183 @item @code{partition-style} (default: @code{'msdos})
29184 The type of partition to create. When set, it must be one of
29185 @code{'msdos}, @code{'none} or a string.
29186 @item @code{partition-alignment} (default: @code{2048})
29187 Alignment of the partition in sectors.
29191 @deffn {Scheme Procedure} debootstrap-variant @var{name} @var{configuration}
29192 This is a helper procedure that creates a @code{ganeti-os-variant} record. It
29193 takes two parameters: a name and a @code{debootstrap-configuration} object.
29196 @deffn {Scheme Procedure} debootstrap-os @var{variants}@dots{}
29197 This is a helper procedure that creates a @code{ganeti-os} record. It takes
29198 a list of variants created with @code{debootstrap-variant}.
29201 @deffn {Scheme Procedure} guix-variant @var{name} @var{configuration}
29202 This is a helper procedure that creates a @code{ganeti-os-variant} record for
29203 use with the Guix OS provider. It takes a name and a G-expression that returns
29204 a ``file-like'' (@pxref{G-Expressions, file-like objects}) object containing a
29205 Guix System configuration.
29208 @deffn {Scheme Procedure} guix-os @var{variants}@dots{}
29209 This is a helper procedure that creates a @code{ganeti-os} record. It
29210 takes a list of variants produced by @code{guix-variant}.
29213 @defvr {Scheme Variable} %default-debootstrap-variants
29214 This is a convenience variable to make the debootstrap provider work
29215 ``out of the box'' without users having to declare variants manually. It
29216 contains a single debootstrap variant with the default configuration:
29219 (list (debootstrap-variant
29221 (debootstrap-configuration)))
29225 @defvr {Scheme Variable} %default-guix-variants
29226 This is a convenience variable to make the Guix OS provider work without
29227 additional configuration. It creates a virtual machine that has an SSH
29228 server, a serial console, and authorizes the Ganeti hosts SSH keys.
29231 (list (guix-variant
29233 (file-append ganeti-instance-guix
29234 "/share/doc/ganeti-instance-guix/examples/dynamic.scm")))
29238 Users can implement support for OS providers unbeknownst to Guix by extending
29239 the @code{ganeti-os} and @code{ganeti-os-variant} records appropriately.
29245 (extension ".conf")
29247 (list (ganeti-os-variant
29249 (configuration (plain-file "bar" "this is fine"))))))
29252 That creates @file{/etc/ganeti/instance-custom/variants/foo.conf} which points
29253 to a file in the store with contents @code{this is fine}. It also creates
29254 @file{/etc/ganeti/instance-custom/variants/variants.list} with contents @code{foo}.
29256 Obviously this may not work for all OS providers out there. If you find the
29257 interface limiting, please reach out to @email{guix-devel@@gnu.org}.
29259 The rest of this section documents the various services that are included by
29260 @code{ganeti-service-type}.
29262 @defvr {Scheme Variable} ganeti-noded-service-type
29263 @command{ganeti-noded} is the daemon responsible for node-specific functions
29264 within the Ganeti system. The value of this service must be a
29265 @code{ganeti-noded-configuration} object.
29268 @deftp {Data Type} ganeti-noded-configuration
29269 This is the configuration for the @code{ganeti-noded} service.
29272 @item @code{ganeti} (default: @code{ganeti})
29273 The @code{ganeti} package to use for this service.
29275 @item @code{port} (default: @code{1811})
29276 The TCP port on which the node daemon listens for network requests.
29278 @item @code{address} (default: @code{"0.0.0.0"})
29279 The network address that the daemon will bind to. The default address means
29280 bind to all available addresses.
29282 @item @code{interface} (default: @code{#f})
29283 When this is set, it must be a specific network interface (e.g.@: @code{eth0})
29284 that the daemon will bind to.
29286 @item @code{max-clients} (default: @code{20})
29287 This sets a limit on the maximum number of simultaneous client connections
29288 that the daemon will handle. Connections above this count are accepted, but
29289 no responses will be sent until enough connections have closed.
29291 @item @code{ssl?} (default: @code{#t})
29292 Whether to use SSL/TLS to encrypt network communications. The certificate
29293 is automatically provisioned by the cluster and can be rotated with
29294 @command{gnt-cluster renew-crypto}.
29296 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
29297 This can be used to provide a specific encryption key for TLS communications.
29299 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
29300 This can be used to provide a specific certificate for TLS communications.
29302 @item @code{debug?} (default: @code{#f})
29303 When true, the daemon performs additional logging for debugging purposes.
29304 Note that this will leak encryption details to the log files, use with caution.
29309 @defvr {Scheme Variable} ganeti-confd-service-type
29310 @command{ganeti-confd} answers queries related to the configuration of a
29311 Ganeti cluster. The purpose of this daemon is to have a highly available
29312 and fast way to query cluster configuration values. It is automatically
29313 active on all @dfn{master candidates}. The value of this service must be a
29314 @code{ganeti-confd-configuration} object.
29318 @deftp {Data Type} ganeti-confd-configuration
29319 This is the configuration for the @code{ganeti-confd} service.
29322 @item @code{ganeti} (default: @code{ganeti})
29323 The @code{ganeti} package to use for this service.
29325 @item @code{port} (default: @code{1814})
29326 The UDP port on which to listen for network requests.
29328 @item @code{address} (default: @code{"0.0.0.0"})
29329 Network address that the daemon will bind to.
29331 @item @code{debug?} (default: @code{#f})
29332 When true, the daemon performs additional logging for debugging purposes.
29337 @defvr {Scheme Variable} ganeti-wconfd-service-type
29338 @command{ganeti-wconfd} is the daemon that has authoritative knowledge
29339 about the cluster configuration and is the only entity that can accept
29340 changes to it. All jobs that need to modify the configuration will do so
29341 by sending appropriate requests to this daemon. It only runs on the
29342 @dfn{master node} and will automatically disable itself on other nodes.
29344 The value of this service must be a
29345 @code{ganeti-wconfd-configuration} object.
29348 @deftp {Data Type} ganeti-wconfd-configuration
29349 This is the configuration for the @code{ganeti-wconfd} service.
29352 @item @code{ganeti} (default: @code{ganeti})
29353 The @code{ganeti} package to use for this service.
29355 @item @code{no-voting?} (default: @code{#f})
29356 The daemon will refuse to start if the majority of cluster nodes does not
29357 agree that it is running on the master node. Set to @code{#t} to start
29358 even if a quorum can not be reached (dangerous, use with caution).
29360 @item @code{debug?} (default: @code{#f})
29361 When true, the daemon performs additional logging for debugging purposes.
29366 @defvr {Scheme Variable} ganeti-luxid-service-type
29367 @command{ganeti-luxid} is a daemon used to answer queries related to the
29368 configuration and the current live state of a Ganeti cluster. Additionally,
29369 it is the authoritative daemon for the Ganeti job queue. Jobs can be
29370 submitted via this daemon and it schedules and starts them.
29372 It takes a @code{ganeti-luxid-configuration} object.
29375 @deftp {Data Type} ganeti-luxid-configuration
29376 This is the configuration for the @code{ganeti-wconfd} service.
29379 @item @code{ganeti} (default: @code{ganeti})
29380 The @code{ganeti} package to use for this service.
29382 @item @code{no-voting?} (default: @code{#f})
29383 The daemon will refuse to start if it cannot verify that the majority of
29384 cluster nodes believes that it is running on the master node. Set to
29385 @code{#t} to ignore such checks and start anyway (this can be dangerous).
29387 @item @code{debug?} (default: @code{#f})
29388 When true, the daemon performs additional logging for debugging purposes.
29393 @defvr {Scheme Variable} ganeti-rapi-service-type
29394 @command{ganeti-rapi} provides a remote API for Ganeti clusters. It runs on
29395 the master node and can be used to perform cluster actions programmatically
29396 via a JSON-based RPC protocol.
29398 Most query operations are allowed without authentication (unless
29399 @var{require-authentication?} is set), whereas write operations require
29400 explicit authorization via the @file{/var/lib/ganeti/rapi/users} file. See
29401 the @url{http://docs.ganeti.org/ganeti/master/html/rapi.html, Ganeti Remote
29402 API documentation} for more information.
29404 The value of this service must be a @code{ganeti-rapi-configuration} object.
29407 @deftp {Data Type} ganeti-rapi-configuration
29408 This is the configuration for the @code{ganeti-rapi} service.
29411 @item @code{ganeti} (default: @code{ganeti})
29412 The @code{ganeti} package to use for this service.
29414 @item @code{require-authentication?} (default: @code{#f})
29415 Whether to require authentication even for read-only operations.
29417 @item @code{port} (default: @code{5080})
29418 The TCP port on which to listen to API requests.
29420 @item @code{address} (default: @code{"0.0.0.0"})
29421 The network address that the service will bind to. By default it listens
29422 on all configured addresses.
29424 @item @code{interface} (default: @code{#f})
29425 When set, it must specify a specific network interface such as @code{eth0}
29426 that the daemon will bind to.
29428 @item @code{max-clients} (default: @code{20})
29429 The maximum number of simultaneous client requests to handle. Further
29430 connections are allowed, but no responses are sent until enough connections
29433 @item @code{ssl?} (default: @code{#t})
29434 Whether to use SSL/TLS encryption on the RAPI port.
29436 @item @code{ssl-key} (default: @file{"/var/lib/ganeti/server.pem"})
29437 This can be used to provide a specific encryption key for TLS communications.
29439 @item @code{ssl-cert} (default: @file{"/var/lib/ganeti/server.pem"})
29440 This can be used to provide a specific certificate for TLS communications.
29442 @item @code{debug?} (default: @code{#f})
29443 When true, the daemon performs additional logging for debugging purposes.
29444 Note that this will leak encryption details to the log files, use with caution.
29449 @defvr {Scheme Variable} ganeti-kvmd-service-type
29450 @command{ganeti-kvmd} is responsible for determining whether a given KVM
29451 instance was shut down by an administrator or a user. Normally Ganeti will
29452 restart an instance that was not stopped through Ganeti itself. If the
29453 cluster option @code{user_shutdown} is true, this daemon monitors the
29454 @code{QMP} socket provided by QEMU and listens for shutdown events, and
29455 marks the instance as @dfn{USER_down} instead of @dfn{ERROR_down} when
29456 it shuts down gracefully by itself.
29458 It takes a @code{ganeti-kvmd-configuration} object.
29461 @deftp {Data Type} ganeti-kvmd-configuration
29464 @item @code{ganeti} (default: @code{ganeti})
29465 The @code{ganeti} package to use for this service.
29467 @item @code{debug?} (default: @code{#f})
29468 When true, the daemon performs additional logging for debugging purposes.
29473 @defvr {Scheme Variable} ganeti-mond-service-type
29474 @command{ganeti-mond} is an optional daemon that provides Ganeti monitoring
29475 functionality. It is responsible for running data collectors and publish the
29476 collected information through a HTTP interface.
29478 It takes a @code{ganeti-mond-configuration} object.
29481 @deftp {Data Type} ganeti-mond-configuration
29484 @item @code{ganeti} (default: @code{ganeti})
29485 The @code{ganeti} package to use for this service.
29487 @item @code{port} (default: @code{1815})
29488 The port on which the daemon will listen.
29490 @item @code{address} (default: @code{"0.0.0.0"})
29491 The network address that the daemon will bind to. By default it binds to all
29492 available interfaces.
29494 @item @code{debug?} (default: @code{#f})
29495 When true, the daemon performs additional logging for debugging purposes.
29500 @defvr {Scheme Variable} ganeti-metad-service-type
29501 @command{ganeti-metad} is an optional daemon that can be used to provide
29502 information about the cluster to instances or OS install scripts.
29504 It takes a @code{ganeti-metad-configuration} object.
29507 @deftp {Data Type} ganeti-metad-configuration
29510 @item @code{ganeti} (default: @code{ganeti})
29511 The @code{ganeti} package to use for this service.
29513 @item @code{port} (default: @code{80})
29514 The port on which the daemon will listen.
29516 @item @code{address} (default: @code{#f})
29517 If set, the daemon will bind to this address only. If left unset, the behavior
29518 depends on the cluster configuration.
29520 @item @code{debug?} (default: @code{#f})
29521 When true, the daemon performs additional logging for debugging purposes.
29526 @defvr {Scheme Variable} ganeti-watcher-service-type
29527 @command{ganeti-watcher} is a script designed to run periodically and ensure
29528 the health of a cluster. It will automatically restart instances that have
29529 stopped without Ganeti's consent, and repairs DRBD links in case a node has
29530 rebooted. It also archives old cluster jobs and restarts Ganeti daemons
29531 that are not running. If the cluster parameter @code{ensure_node_health}
29532 is set, the watcher will also shutdown instances and DRBD devices if the
29533 node it is running on is declared offline by known master candidates.
29535 It can be paused on all nodes with @command{gnt-cluster watcher pause}.
29537 The service takes a @code{ganeti-watcher-configuration} object.
29540 @deftp {Data Type} ganeti-watcher-configuration
29543 @item @code{ganeti} (default: @code{ganeti})
29544 The @code{ganeti} package to use for this service.
29546 @item @code{schedule} (default: @code{'(next-second-from (next-minute (range 0 60 5)))})
29547 How often to run the script. The default is every five minutes.
29549 @item @code{rapi-ip} (default: @code{#f})
29550 This option needs to be specified only if the RAPI daemon is configured to use
29551 a particular interface or address. By default the cluster address is used.
29553 @item @code{job-age} (default: @code{(* 6 3600)})
29554 Archive cluster jobs older than this age, specified in seconds. The default
29555 is 6 hours. This keeps @command{gnt-job list} manageable.
29557 @item @code{verify-disks?} (default: @code{#t})
29558 If this is @code{#f}, the watcher will not try to repair broken DRBD links
29559 automatically. Administrators will need to use @command{gnt-cluster verify-disks}
29562 @item @code{debug?} (default: @code{#f})
29563 When @code{#t}, the script performs additional logging for debugging purposes.
29568 @defvr {Scheme Variable} ganeti-cleaner-service-type
29569 @command{ganeti-cleaner} is a script designed to run periodically and remove
29570 old files from the cluster. This service type controls two @dfn{cron jobs}:
29571 one intended for the master node that permanently purges old cluster jobs,
29572 and one intended for every node that removes expired X509 certificates, keys,
29573 and outdated @command{ganeti-watcher} information. Like all Ganeti services,
29574 it is safe to include even on non-master nodes as it will disable itself as
29577 It takes a @code{ganeti-cleaner-configuration} object.
29580 @deftp {Data Type} ganeti-cleaner-configuration
29583 @item @code{ganeti} (default: @code{ganeti})
29584 The @code{ganeti} package to use for the @command{gnt-cleaner} command.
29586 @item @code{master-schedule} (default: @code{"45 1 * * *"})
29587 How often to run the master cleaning job. The default is once per day, at
29590 @item @code{node-schedule} (default: @code{"45 2 * * *"})
29591 How often to run the node cleaning job. The default is once per day, at
29597 @node Version Control Services
29598 @subsection Version Control Services
29600 The @code{(gnu services version-control)} module provides a service to
29601 allow remote access to local Git repositories. There are three options:
29602 the @code{git-daemon-service}, which provides access to repositories via
29603 the @code{git://} unsecured TCP-based protocol, extending the
29604 @code{nginx} web server to proxy some requests to
29605 @code{git-http-backend}, or providing a web interface with
29606 @code{cgit-service-type}.
29608 @deffn {Scheme Procedure} git-daemon-service [#:config (git-daemon-configuration)]
29610 Return a service that runs @command{git daemon}, a simple TCP server to
29611 expose repositories over the Git protocol for anonymous access.
29613 The optional @var{config} argument should be a
29614 @code{<git-daemon-configuration>} object, by default it allows read-only
29615 access to exported@footnote{By creating the magic file
29616 @file{git-daemon-export-ok} in the repository directory.} repositories under
29621 @deftp {Data Type} git-daemon-configuration
29622 Data type representing the configuration for @code{git-daemon-service}.
29625 @item @code{package} (default: @code{git})
29626 Package object of the Git distributed version control system.
29628 @item @code{export-all?} (default: @code{#f})
29629 Whether to allow access for all Git repositories, even if they do not
29630 have the @file{git-daemon-export-ok} file.
29632 @item @code{base-path} (default: @file{/srv/git})
29633 Whether to remap all the path requests as relative to the given path.
29634 If you run @command{git daemon} with @code{(base-path "/srv/git")} on
29635 @samp{example.com}, then if you later try to pull
29636 @indicateurl{git://example.com/hello.git}, git daemon will interpret the
29637 path as @file{/srv/git/hello.git}.
29639 @item @code{user-path} (default: @code{#f})
29640 Whether to allow @code{~user} notation to be used in requests. When
29641 specified with empty string, requests to
29642 @indicateurl{git://host/~alice/foo} is taken as a request to access
29643 @code{foo} repository in the home directory of user @code{alice}. If
29644 @code{(user-path "@var{path}")} is specified, the same request is taken
29645 as a request to access @file{@var{path}/foo} repository in the home
29646 directory of user @code{alice}.
29648 @item @code{listen} (default: @code{'()})
29649 Whether to listen on specific IP addresses or hostnames, defaults to
29652 @item @code{port} (default: @code{#f})
29653 Whether to listen on an alternative port, which defaults to 9418.
29655 @item @code{whitelist} (default: @code{'()})
29656 If not empty, only allow access to this list of directories.
29658 @item @code{extra-options} (default: @code{'()})
29659 Extra options will be passed to @command{git daemon}, please run
29660 @command{man git-daemon} for more information.
29665 The @code{git://} protocol lacks authentication. When you pull from a
29666 repository fetched via @code{git://}, you don't know whether the data you
29667 receive was modified or is even coming from the specified host, and your
29668 connection is subject to eavesdropping. It's better to use an authenticated
29669 and encrypted transport, such as @code{https}. Although Git allows you
29670 to serve repositories using unsophisticated file-based web servers,
29671 there is a faster protocol implemented by the @code{git-http-backend}
29672 program. This program is the back-end of a proper Git web service. It
29673 is designed to sit behind a FastCGI proxy. @xref{Web Services}, for more
29674 on running the necessary @code{fcgiwrap} daemon.
29676 Guix has a separate configuration data type for serving Git repositories
29679 @deftp {Data Type} git-http-configuration
29680 Data type representing the configuration for a future
29681 @code{git-http-service-type}; can currently be used to configure Nginx
29682 through @code{git-http-nginx-location-configuration}.
29685 @item @code{package} (default: @var{git})
29686 Package object of the Git distributed version control system.
29688 @item @code{git-root} (default: @file{/srv/git})
29689 Directory containing the Git repositories to expose to the world.
29691 @item @code{export-all?} (default: @code{#f})
29692 Whether to expose access for all Git repositories in @var{git-root},
29693 even if they do not have the @file{git-daemon-export-ok} file.
29695 @item @code{uri-path} (default: @samp{/git/})
29696 Path prefix for Git access. With the default @samp{/git/} prefix, this
29697 will map @indicateurl{http://@var{server}/git/@var{repo}.git} to
29698 @file{/srv/git/@var{repo}.git}. Requests whose URI paths do not begin
29699 with this prefix are not passed on to this Git instance.
29701 @item @code{fcgiwrap-socket} (default: @code{127.0.0.1:9000})
29702 The socket on which the @code{fcgiwrap} daemon is listening. @xref{Web
29707 There is no @code{git-http-service-type}, currently; instead you can
29708 create an @code{nginx-location-configuration} from a
29709 @code{git-http-configuration} and then add that location to a web
29712 @deffn {Scheme Procedure} git-http-nginx-location-configuration @
29713 [config=(git-http-configuration)]
29714 Compute an @code{nginx-location-configuration} that corresponds to the
29715 given Git http configuration. An example nginx service definition to
29716 serve the default @file{/srv/git} over HTTPS might be:
29719 (service nginx-service-type
29720 (nginx-configuration
29723 (nginx-server-configuration
29724 (listen '("443 ssl"))
29725 (server-name "git.my-host.org")
29727 "/etc/letsencrypt/live/git.my-host.org/fullchain.pem")
29728 (ssl-certificate-key
29729 "/etc/letsencrypt/live/git.my-host.org/privkey.pem")
29732 (git-http-nginx-location-configuration
29733 (git-http-configuration (uri-path "/"))))))))))
29736 This example assumes that you are using Let's Encrypt to get your TLS
29737 certificate. @xref{Certificate Services}. The default @code{certbot}
29738 service will redirect all HTTP traffic on @code{git.my-host.org} to
29739 HTTPS@. You will also need to add an @code{fcgiwrap} proxy to your
29740 system services. @xref{Web Services}.
29743 @subsubheading Cgit Service
29745 @cindex Cgit service
29746 @cindex Git, web interface
29747 @uref{https://git.zx2c4.com/cgit/, Cgit} is a web frontend for Git
29748 repositories written in C.
29750 The following example will configure the service with default values.
29751 By default, Cgit can be accessed on port 80 (@code{http://localhost:80}).
29754 (service cgit-service-type)
29757 The @code{file-object} type designates either a file-like object
29758 (@pxref{G-Expressions, file-like objects}) or a string.
29760 @c %start of fragment
29762 Available @code{cgit-configuration} fields are:
29764 @deftypevr {@code{cgit-configuration} parameter} package package
29769 @deftypevr {@code{cgit-configuration} parameter} nginx-server-configuration-list nginx
29770 NGINX configuration.
29774 @deftypevr {@code{cgit-configuration} parameter} file-object about-filter
29775 Specifies a command which will be invoked to format the content of about
29776 pages (both top-level and for each repository).
29778 Defaults to @samp{""}.
29782 @deftypevr {@code{cgit-configuration} parameter} string agefile
29783 Specifies a path, relative to each repository path, which can be used to
29784 specify the date and time of the youngest commit in the repository.
29786 Defaults to @samp{""}.
29790 @deftypevr {@code{cgit-configuration} parameter} file-object auth-filter
29791 Specifies a command that will be invoked for authenticating repository
29794 Defaults to @samp{""}.
29798 @deftypevr {@code{cgit-configuration} parameter} string branch-sort
29799 Flag which, when set to @samp{age}, enables date ordering in the branch
29800 ref list, and when set @samp{name} enables ordering by branch name.
29802 Defaults to @samp{"name"}.
29806 @deftypevr {@code{cgit-configuration} parameter} string cache-root
29807 Path used to store the cgit cache entries.
29809 Defaults to @samp{"/var/cache/cgit"}.
29813 @deftypevr {@code{cgit-configuration} parameter} integer cache-static-ttl
29814 Number which specifies the time-to-live, in minutes, for the cached
29815 version of repository pages accessed with a fixed SHA1.
29817 Defaults to @samp{-1}.
29821 @deftypevr {@code{cgit-configuration} parameter} integer cache-dynamic-ttl
29822 Number which specifies the time-to-live, in minutes, for the cached
29823 version of repository pages accessed without a fixed SHA1.
29825 Defaults to @samp{5}.
29829 @deftypevr {@code{cgit-configuration} parameter} integer cache-repo-ttl
29830 Number which specifies the time-to-live, in minutes, for the cached
29831 version of the repository summary page.
29833 Defaults to @samp{5}.
29837 @deftypevr {@code{cgit-configuration} parameter} integer cache-root-ttl
29838 Number which specifies the time-to-live, in minutes, for the cached
29839 version of the repository index page.
29841 Defaults to @samp{5}.
29845 @deftypevr {@code{cgit-configuration} parameter} integer cache-scanrc-ttl
29846 Number which specifies the time-to-live, in minutes, for the result of
29847 scanning a path for Git repositories.
29849 Defaults to @samp{15}.
29853 @deftypevr {@code{cgit-configuration} parameter} integer cache-about-ttl
29854 Number which specifies the time-to-live, in minutes, for the cached
29855 version of the repository about page.
29857 Defaults to @samp{15}.
29861 @deftypevr {@code{cgit-configuration} parameter} integer cache-snapshot-ttl
29862 Number which specifies the time-to-live, in minutes, for the cached
29863 version of snapshots.
29865 Defaults to @samp{5}.
29869 @deftypevr {@code{cgit-configuration} parameter} integer cache-size
29870 The maximum number of entries in the cgit cache. When set to @samp{0},
29871 caching is disabled.
29873 Defaults to @samp{0}.
29877 @deftypevr {@code{cgit-configuration} parameter} boolean case-sensitive-sort?
29878 Sort items in the repo list case sensitively.
29880 Defaults to @samp{#t}.
29884 @deftypevr {@code{cgit-configuration} parameter} list clone-prefix
29885 List of common prefixes which, when combined with a repository URL,
29886 generates valid clone URLs for the repository.
29888 Defaults to @samp{()}.
29892 @deftypevr {@code{cgit-configuration} parameter} list clone-url
29893 List of @code{clone-url} templates.
29895 Defaults to @samp{()}.
29899 @deftypevr {@code{cgit-configuration} parameter} file-object commit-filter
29900 Command which will be invoked to format commit messages.
29902 Defaults to @samp{""}.
29906 @deftypevr {@code{cgit-configuration} parameter} string commit-sort
29907 Flag which, when set to @samp{date}, enables strict date ordering in the
29908 commit log, and when set to @samp{topo} enables strict topological
29911 Defaults to @samp{"git log"}.
29915 @deftypevr {@code{cgit-configuration} parameter} file-object css
29916 URL which specifies the css document to include in all cgit pages.
29918 Defaults to @samp{"/share/cgit/cgit.css"}.
29922 @deftypevr {@code{cgit-configuration} parameter} file-object email-filter
29923 Specifies a command which will be invoked to format names and email
29924 address of committers, authors, and taggers, as represented in various
29925 places throughout the cgit interface.
29927 Defaults to @samp{""}.
29931 @deftypevr {@code{cgit-configuration} parameter} boolean embedded?
29932 Flag which, when set to @samp{#t}, will make cgit generate a HTML
29933 fragment suitable for embedding in other HTML pages.
29935 Defaults to @samp{#f}.
29939 @deftypevr {@code{cgit-configuration} parameter} boolean enable-commit-graph?
29940 Flag which, when set to @samp{#t}, will make cgit print an ASCII-art
29941 commit history graph to the left of the commit messages in the
29942 repository log page.
29944 Defaults to @samp{#f}.
29948 @deftypevr {@code{cgit-configuration} parameter} boolean enable-filter-overrides?
29949 Flag which, when set to @samp{#t}, allows all filter settings to be
29950 overridden in repository-specific cgitrc files.
29952 Defaults to @samp{#f}.
29956 @deftypevr {@code{cgit-configuration} parameter} boolean enable-follow-links?
29957 Flag which, when set to @samp{#t}, allows users to follow a file in the
29960 Defaults to @samp{#f}.
29964 @deftypevr {@code{cgit-configuration} parameter} boolean enable-http-clone?
29965 If set to @samp{#t}, cgit will act as an dumb HTTP endpoint for Git
29968 Defaults to @samp{#t}.
29972 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-links?
29973 Flag which, when set to @samp{#t}, will make cgit generate extra links
29974 "summary", "commit", "tree" for each repo in the repository index.
29976 Defaults to @samp{#f}.
29980 @deftypevr {@code{cgit-configuration} parameter} boolean enable-index-owner?
29981 Flag which, when set to @samp{#t}, will make cgit display the owner of
29982 each repo in the repository index.
29984 Defaults to @samp{#t}.
29988 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-filecount?
29989 Flag which, when set to @samp{#t}, will make cgit print the number of
29990 modified files for each commit on the repository log page.
29992 Defaults to @samp{#f}.
29996 @deftypevr {@code{cgit-configuration} parameter} boolean enable-log-linecount?
29997 Flag which, when set to @samp{#t}, will make cgit print the number of
29998 added and removed lines for each commit on the repository log page.
30000 Defaults to @samp{#f}.
30004 @deftypevr {@code{cgit-configuration} parameter} boolean enable-remote-branches?
30005 Flag which, when set to @code{#t}, will make cgit display remote
30006 branches in the summary and refs views.
30008 Defaults to @samp{#f}.
30012 @deftypevr {@code{cgit-configuration} parameter} boolean enable-subject-links?
30013 Flag which, when set to @code{1}, will make cgit use the subject of the
30014 parent commit as link text when generating links to parent commits in
30017 Defaults to @samp{#f}.
30021 @deftypevr {@code{cgit-configuration} parameter} boolean enable-html-serving?
30022 Flag which, when set to @samp{#t}, will make cgit use the subject of the
30023 parent commit as link text when generating links to parent commits in
30026 Defaults to @samp{#f}.
30030 @deftypevr {@code{cgit-configuration} parameter} boolean enable-tree-linenumbers?
30031 Flag which, when set to @samp{#t}, will make cgit generate linenumber
30032 links for plaintext blobs printed in the tree view.
30034 Defaults to @samp{#t}.
30038 @deftypevr {@code{cgit-configuration} parameter} boolean enable-git-config?
30039 Flag which, when set to @samp{#f}, will allow cgit to use Git config to
30040 set any repo specific settings.
30042 Defaults to @samp{#f}.
30046 @deftypevr {@code{cgit-configuration} parameter} file-object favicon
30047 URL used as link to a shortcut icon for cgit.
30049 Defaults to @samp{"/favicon.ico"}.
30053 @deftypevr {@code{cgit-configuration} parameter} string footer
30054 The content of the file specified with this option will be included
30055 verbatim at the bottom of all pages (i.e.@: it replaces the standard
30056 "generated by..."@: message).
30058 Defaults to @samp{""}.
30062 @deftypevr {@code{cgit-configuration} parameter} string head-include
30063 The content of the file specified with this option will be included
30064 verbatim in the HTML HEAD section on all pages.
30066 Defaults to @samp{""}.
30070 @deftypevr {@code{cgit-configuration} parameter} string header
30071 The content of the file specified with this option will be included
30072 verbatim at the top of all pages.
30074 Defaults to @samp{""}.
30078 @deftypevr {@code{cgit-configuration} parameter} file-object include
30079 Name of a configfile to include before the rest of the current config-
30082 Defaults to @samp{""}.
30086 @deftypevr {@code{cgit-configuration} parameter} string index-header
30087 The content of the file specified with this option will be included
30088 verbatim above the repository index.
30090 Defaults to @samp{""}.
30094 @deftypevr {@code{cgit-configuration} parameter} string index-info
30095 The content of the file specified with this option will be included
30096 verbatim below the heading on the repository index page.
30098 Defaults to @samp{""}.
30102 @deftypevr {@code{cgit-configuration} parameter} boolean local-time?
30103 Flag which, if set to @samp{#t}, makes cgit print commit and tag times
30104 in the servers timezone.
30106 Defaults to @samp{#f}.
30110 @deftypevr {@code{cgit-configuration} parameter} file-object logo
30111 URL which specifies the source of an image which will be used as a logo
30114 Defaults to @samp{"/share/cgit/cgit.png"}.
30118 @deftypevr {@code{cgit-configuration} parameter} string logo-link
30119 URL loaded when clicking on the cgit logo image.
30121 Defaults to @samp{""}.
30125 @deftypevr {@code{cgit-configuration} parameter} file-object owner-filter
30126 Command which will be invoked to format the Owner column of the main
30129 Defaults to @samp{""}.
30133 @deftypevr {@code{cgit-configuration} parameter} integer max-atom-items
30134 Number of items to display in atom feeds view.
30136 Defaults to @samp{10}.
30140 @deftypevr {@code{cgit-configuration} parameter} integer max-commit-count
30141 Number of entries to list per page in "log" view.
30143 Defaults to @samp{50}.
30147 @deftypevr {@code{cgit-configuration} parameter} integer max-message-length
30148 Number of commit message characters to display in "log" view.
30150 Defaults to @samp{80}.
30154 @deftypevr {@code{cgit-configuration} parameter} integer max-repo-count
30155 Specifies the number of entries to list per page on the repository index
30158 Defaults to @samp{50}.
30162 @deftypevr {@code{cgit-configuration} parameter} integer max-repodesc-length
30163 Specifies the maximum number of repo description characters to display
30164 on the repository index page.
30166 Defaults to @samp{80}.
30170 @deftypevr {@code{cgit-configuration} parameter} integer max-blob-size
30171 Specifies the maximum size of a blob to display HTML for in KBytes.
30173 Defaults to @samp{0}.
30177 @deftypevr {@code{cgit-configuration} parameter} string max-stats
30178 Maximum statistics period. Valid values are @samp{week},@samp{month},
30179 @samp{quarter} and @samp{year}.
30181 Defaults to @samp{""}.
30185 @deftypevr {@code{cgit-configuration} parameter} mimetype-alist mimetype
30186 Mimetype for the specified filename extension.
30188 Defaults to @samp{((gif "image/gif") (html "text/html") (jpg
30189 "image/jpeg") (jpeg "image/jpeg") (pdf "application/pdf") (png
30190 "image/png") (svg "image/svg+xml"))}.
30194 @deftypevr {@code{cgit-configuration} parameter} file-object mimetype-file
30195 Specifies the file to use for automatic mimetype lookup.
30197 Defaults to @samp{""}.
30201 @deftypevr {@code{cgit-configuration} parameter} string module-link
30202 Text which will be used as the formatstring for a hyperlink when a
30203 submodule is printed in a directory listing.
30205 Defaults to @samp{""}.
30209 @deftypevr {@code{cgit-configuration} parameter} boolean nocache?
30210 If set to the value @samp{#t} caching will be disabled.
30212 Defaults to @samp{#f}.
30216 @deftypevr {@code{cgit-configuration} parameter} boolean noplainemail?
30217 If set to @samp{#t} showing full author email addresses will be
30220 Defaults to @samp{#f}.
30224 @deftypevr {@code{cgit-configuration} parameter} boolean noheader?
30225 Flag which, when set to @samp{#t}, will make cgit omit the standard
30226 header on all pages.
30228 Defaults to @samp{#f}.
30232 @deftypevr {@code{cgit-configuration} parameter} project-list project-list
30233 A list of subdirectories inside of @code{repository-directory}, relative
30234 to it, that should loaded as Git repositories. An empty list means that
30235 all subdirectories will be loaded.
30237 Defaults to @samp{()}.
30241 @deftypevr {@code{cgit-configuration} parameter} file-object readme
30242 Text which will be used as default value for @code{cgit-repo-readme}.
30244 Defaults to @samp{""}.
30248 @deftypevr {@code{cgit-configuration} parameter} boolean remove-suffix?
30249 If set to @code{#t} and @code{repository-directory} is enabled, if any
30250 repositories are found with a suffix of @code{.git}, this suffix will be
30251 removed for the URL and name.
30253 Defaults to @samp{#f}.
30257 @deftypevr {@code{cgit-configuration} parameter} integer renamelimit
30258 Maximum number of files to consider when detecting renames.
30260 Defaults to @samp{-1}.
30264 @deftypevr {@code{cgit-configuration} parameter} string repository-sort
30265 The way in which repositories in each section are sorted.
30267 Defaults to @samp{""}.
30271 @deftypevr {@code{cgit-configuration} parameter} robots-list robots
30272 Text used as content for the @code{robots} meta-tag.
30274 Defaults to @samp{("noindex" "nofollow")}.
30278 @deftypevr {@code{cgit-configuration} parameter} string root-desc
30279 Text printed below the heading on the repository index page.
30281 Defaults to @samp{"a fast webinterface for the git dscm"}.
30285 @deftypevr {@code{cgit-configuration} parameter} string root-readme
30286 The content of the file specified with this option will be included
30287 verbatim below the ``about'' link on the repository index page.
30289 Defaults to @samp{""}.
30293 @deftypevr {@code{cgit-configuration} parameter} string root-title
30294 Text printed as heading on the repository index page.
30296 Defaults to @samp{""}.
30300 @deftypevr {@code{cgit-configuration} parameter} boolean scan-hidden-path
30301 If set to @samp{#t} and repository-directory is enabled,
30302 repository-directory will recurse into directories whose name starts
30303 with a period. Otherwise, repository-directory will stay away from such
30304 directories, considered as ``hidden''. Note that this does not apply to
30305 the @file{.git} directory in non-bare repos.
30307 Defaults to @samp{#f}.
30311 @deftypevr {@code{cgit-configuration} parameter} list snapshots
30312 Text which specifies the default set of snapshot formats that cgit
30313 generates links for.
30315 Defaults to @samp{()}.
30319 @deftypevr {@code{cgit-configuration} parameter} repository-directory repository-directory
30320 Name of the directory to scan for repositories (represents
30323 Defaults to @samp{"/srv/git"}.
30327 @deftypevr {@code{cgit-configuration} parameter} string section
30328 The name of the current repository section - all repositories defined
30329 after this option will inherit the current section name.
30331 Defaults to @samp{""}.
30335 @deftypevr {@code{cgit-configuration} parameter} string section-sort
30336 Flag which, when set to @samp{1}, will sort the sections on the
30337 repository listing by name.
30339 Defaults to @samp{""}.
30343 @deftypevr {@code{cgit-configuration} parameter} integer section-from-path
30344 A number which, if defined prior to repository-directory, specifies how
30345 many path elements from each repo path to use as a default section name.
30347 Defaults to @samp{0}.
30351 @deftypevr {@code{cgit-configuration} parameter} boolean side-by-side-diffs?
30352 If set to @samp{#t} shows side-by-side diffs instead of unidiffs per
30355 Defaults to @samp{#f}.
30359 @deftypevr {@code{cgit-configuration} parameter} file-object source-filter
30360 Specifies a command which will be invoked to format plaintext blobs in
30363 Defaults to @samp{""}.
30367 @deftypevr {@code{cgit-configuration} parameter} integer summary-branches
30368 Specifies the number of branches to display in the repository ``summary''
30371 Defaults to @samp{10}.
30375 @deftypevr {@code{cgit-configuration} parameter} integer summary-log
30376 Specifies the number of log entries to display in the repository
30379 Defaults to @samp{10}.
30383 @deftypevr {@code{cgit-configuration} parameter} integer summary-tags
30384 Specifies the number of tags to display in the repository ``summary''
30387 Defaults to @samp{10}.
30391 @deftypevr {@code{cgit-configuration} parameter} string strict-export
30392 Filename which, if specified, needs to be present within the repository
30393 for cgit to allow access to that repository.
30395 Defaults to @samp{""}.
30399 @deftypevr {@code{cgit-configuration} parameter} string virtual-root
30400 URL which, if specified, will be used as root for all cgit links.
30402 Defaults to @samp{"/"}.
30406 @deftypevr {@code{cgit-configuration} parameter} repository-cgit-configuration-list repositories
30407 A list of @dfn{cgit-repo} records to use with config.
30409 Defaults to @samp{()}.
30411 Available @code{repository-cgit-configuration} fields are:
30413 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list snapshots
30414 A mask of snapshot formats for this repo that cgit generates links for,
30415 restricted by the global @code{snapshots} setting.
30417 Defaults to @samp{()}.
30421 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object source-filter
30422 Override the default @code{source-filter}.
30424 Defaults to @samp{""}.
30428 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string url
30429 The relative URL used to access the repository.
30431 Defaults to @samp{""}.
30435 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object about-filter
30436 Override the default @code{about-filter}.
30438 Defaults to @samp{""}.
30442 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string branch-sort
30443 Flag which, when set to @samp{age}, enables date ordering in the branch
30444 ref list, and when set to @samp{name} enables ordering by branch name.
30446 Defaults to @samp{""}.
30450 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list clone-url
30451 A list of URLs which can be used to clone repo.
30453 Defaults to @samp{()}.
30457 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object commit-filter
30458 Override the default @code{commit-filter}.
30460 Defaults to @samp{""}.
30464 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string commit-sort
30465 Flag which, when set to @samp{date}, enables strict date ordering in the
30466 commit log, and when set to @samp{topo} enables strict topological
30469 Defaults to @samp{""}.
30473 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string defbranch
30474 The name of the default branch for this repository. If no such branch
30475 exists in the repository, the first branch name (when sorted) is used as
30476 default instead. By default branch pointed to by HEAD, or ``master'' if
30477 there is no suitable HEAD.
30479 Defaults to @samp{""}.
30483 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string desc
30484 The value to show as repository description.
30486 Defaults to @samp{""}.
30490 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string homepage
30491 The value to show as repository homepage.
30493 Defaults to @samp{""}.
30497 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object email-filter
30498 Override the default @code{email-filter}.
30500 Defaults to @samp{""}.
30504 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-commit-graph?
30505 A flag which can be used to disable the global setting
30506 @code{enable-commit-graph?}.
30508 Defaults to @samp{disabled}.
30512 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-filecount?
30513 A flag which can be used to disable the global setting
30514 @code{enable-log-filecount?}.
30516 Defaults to @samp{disabled}.
30520 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-log-linecount?
30521 A flag which can be used to disable the global setting
30522 @code{enable-log-linecount?}.
30524 Defaults to @samp{disabled}.
30528 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-remote-branches?
30529 Flag which, when set to @code{#t}, will make cgit display remote
30530 branches in the summary and refs views.
30532 Defaults to @samp{disabled}.
30536 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-subject-links?
30537 A flag which can be used to override the global setting
30538 @code{enable-subject-links?}.
30540 Defaults to @samp{disabled}.
30544 @deftypevr {@code{repository-cgit-configuration} parameter} maybe-repo-boolean enable-html-serving?
30545 A flag which can be used to override the global setting
30546 @code{enable-html-serving?}.
30548 Defaults to @samp{disabled}.
30552 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean hide?
30553 Flag which, when set to @code{#t}, hides the repository from the
30556 Defaults to @samp{#f}.
30560 @deftypevr {@code{repository-cgit-configuration} parameter} repo-boolean ignore?
30561 Flag which, when set to @samp{#t}, ignores the repository.
30563 Defaults to @samp{#f}.
30567 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object logo
30568 URL which specifies the source of an image which will be used as a logo
30569 on this repo’s pages.
30571 Defaults to @samp{""}.
30575 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string logo-link
30576 URL loaded when clicking on the cgit logo image.
30578 Defaults to @samp{""}.
30582 @deftypevr {@code{repository-cgit-configuration} parameter} repo-file-object owner-filter
30583 Override the default @code{owner-filter}.
30585 Defaults to @samp{""}.
30589 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string module-link
30590 Text which will be used as the formatstring for a hyperlink when a
30591 submodule is printed in a directory listing. The arguments for the
30592 formatstring are the path and SHA1 of the submodule commit.
30594 Defaults to @samp{""}.
30598 @deftypevr {@code{repository-cgit-configuration} parameter} module-link-path module-link-path
30599 Text which will be used as the formatstring for a hyperlink when a
30600 submodule with the specified subdirectory path is printed in a directory
30603 Defaults to @samp{()}.
30607 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string max-stats
30608 Override the default maximum statistics period.
30610 Defaults to @samp{""}.
30614 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string name
30615 The value to show as repository name.
30617 Defaults to @samp{""}.
30621 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string owner
30622 A value used to identify the owner of the repository.
30624 Defaults to @samp{""}.
30628 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string path
30629 An absolute path to the repository directory.
30631 Defaults to @samp{""}.
30635 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string readme
30636 A path (relative to repo) which specifies a file to include verbatim as
30637 the ``About'' page for this repo.
30639 Defaults to @samp{""}.
30643 @deftypevr {@code{repository-cgit-configuration} parameter} repo-string section
30644 The name of the current repository section - all repositories defined
30645 after this option will inherit the current section name.
30647 Defaults to @samp{""}.
30651 @deftypevr {@code{repository-cgit-configuration} parameter} repo-list extra-options
30652 Extra options will be appended to cgitrc file.
30654 Defaults to @samp{()}.
30660 @deftypevr {@code{cgit-configuration} parameter} list extra-options
30661 Extra options will be appended to cgitrc file.
30663 Defaults to @samp{()}.
30668 @c %end of fragment
30670 However, it could be that you just want to get a @code{cgitrc} up and
30671 running. In that case, you can pass an @code{opaque-cgit-configuration}
30672 as a record to @code{cgit-service-type}. As its name indicates, an
30673 opaque configuration does not have easy reflective capabilities.
30675 Available @code{opaque-cgit-configuration} fields are:
30677 @deftypevr {@code{opaque-cgit-configuration} parameter} package cgit
30681 @deftypevr {@code{opaque-cgit-configuration} parameter} string string
30682 The contents of the @code{cgitrc}, as a string.
30685 For example, if your @code{cgitrc} is just the empty string, you
30686 could instantiate a cgit service like this:
30689 (service cgit-service-type
30690 (opaque-cgit-configuration
30694 @subsubheading Gitolite Service
30696 @cindex Gitolite service
30697 @cindex Git, hosting
30698 @uref{https://gitolite.com/gitolite/, Gitolite} is a tool for hosting Git
30699 repositories on a central server.
30701 Gitolite can handle multiple repositories and users, and supports flexible
30702 configuration of the permissions for the users on the repositories.
30704 The following example will configure Gitolite using the default @code{git}
30705 user, and the provided SSH public key.
30708 (service gitolite-service-type
30709 (gitolite-configuration
30710 (admin-pubkey (plain-file
30712 "ssh-rsa AAAA... guix@@example.com"))))
30715 Gitolite is configured through a special admin repository which you can clone,
30716 for example, if you setup Gitolite on @code{example.com}, you would run the
30717 following command to clone the admin repository.
30720 git clone git@@example.com:gitolite-admin
30723 When the Gitolite service is activated, the provided @code{admin-pubkey} will
30724 be inserted in to the @file{keydir} directory in the gitolite-admin
30725 repository. If this results in a change in the repository, it will be
30726 committed using the message ``gitolite setup by GNU Guix''.
30728 @deftp {Data Type} gitolite-configuration
30729 Data type representing the configuration for @code{gitolite-service-type}.
30732 @item @code{package} (default: @var{gitolite})
30733 Gitolite package to use.
30735 @item @code{user} (default: @var{git})
30736 User to use for Gitolite. This will be user that you use when accessing
30739 @item @code{group} (default: @var{git})
30740 Group to use for Gitolite.
30742 @item @code{home-directory} (default: @var{"/var/lib/gitolite"})
30743 Directory in which to store the Gitolite configuration and repositories.
30745 @item @code{rc-file} (default: @var{(gitolite-rc-file)})
30746 A ``file-like'' object (@pxref{G-Expressions, file-like objects}),
30747 representing the configuration for Gitolite.
30749 @item @code{admin-pubkey} (default: @var{#f})
30750 A ``file-like'' object (@pxref{G-Expressions, file-like objects}) used to
30751 setup Gitolite. This will be inserted in to the @file{keydir} directory
30752 within the gitolite-admin repository.
30754 To specify the SSH key as a string, use the @code{plain-file} function.
30757 (plain-file "yourname.pub" "ssh-rsa AAAA... guix@@example.com")
30763 @deftp {Data Type} gitolite-rc-file
30764 Data type representing the Gitolite RC file.
30767 @item @code{umask} (default: @code{#o0077})
30768 This controls the permissions Gitolite sets on the repositories and their
30771 A value like @code{#o0027} will give read access to the group used by Gitolite
30772 (by default: @code{git}). This is necessary when using Gitolite with software
30773 like cgit or gitweb.
30775 @item @code{git-config-keys} (default: @code{""})
30776 Gitolite allows you to set git config values using the @samp{config}
30777 keyword. This setting allows control over the config keys to accept.
30779 @item @code{roles} (default: @code{'(("READERS" . 1) ("WRITERS" . ))})
30780 Set the role names allowed to be used by users running the perms command.
30782 @item @code{enable} (default: @code{'("help" "desc" "info" "perms" "writable" "ssh-authkeys" "git-config" "daemon" "gitweb")})
30783 This setting controls the commands and features to enable within Gitolite.
30789 @node Game Services
30790 @subsection Game Services
30792 @subsubheading The Battle for Wesnoth Service
30794 @uref{https://wesnoth.org, The Battle for Wesnoth} is a fantasy, turn
30795 based tactical strategy game, with several single player campaigns, and
30796 multiplayer games (both networked and local).
30798 @defvar {Scheme Variable} wesnothd-service-type
30799 Service type for the wesnothd service. Its value must be a
30800 @code{wesnothd-configuration} object. To run wesnothd in the default
30801 configuration, instantiate it as:
30804 (service wesnothd-service-type)
30808 @deftp {Data Type} wesnothd-configuration
30809 Data type representing the configuration of @command{wesnothd}.
30812 @item @code{package} (default: @code{wesnoth-server})
30813 The wesnoth server package to use.
30815 @item @code{port} (default: @code{15000})
30816 The port to bind the server to.
30821 @node PAM Mount Service
30822 @subsection PAM Mount Service
30825 The @code{(gnu services pam-mount)} module provides a service allowing
30826 users to mount volumes when they log in. It should be able to mount any
30827 volume format supported by the system.
30829 @defvar {Scheme Variable} pam-mount-service-type
30830 Service type for PAM Mount support.
30833 @deftp {Data Type} pam-mount-configuration
30834 Data type representing the configuration of PAM Mount.
30836 It takes the following parameters:
30840 The configuration rules that will be used to generate
30841 @file{/etc/security/pam_mount.conf.xml}.
30843 The configuration rules are SXML elements (@pxref{SXML,,, guile, GNU
30844 Guile Reference Manual}), and the default ones don't mount anything for
30848 `((debug (@@ (enable "0")))
30849 (mntoptions (@@ (allow ,(string-join
30850 '("nosuid" "nodev" "loop"
30851 "encryption" "fsck" "nonempty"
30852 "allow_root" "allow_other")
30854 (mntoptions (@@ (require "nosuid,nodev")))
30855 (logout (@@ (wait "0")
30859 (mkmountpoint (@@ (enable "1")
30863 Some @code{volume} elements must be added to automatically mount volumes
30864 at login. Here's an example allowing the user @code{alice} to mount her
30865 encrypted @env{HOME} directory and allowing the user @code{bob} to mount
30866 the partition where he stores his data:
30869 (define pam-mount-rules
30870 `((debug (@@ (enable "0")))
30871 (volume (@@ (user "alice")
30874 (mountpoint "/home/alice")))
30875 (volume (@@ (user "bob")
30878 (mountpoint "/home/bob/data")
30879 (options "defaults,autodefrag,compress")))
30880 (mntoptions (@@ (allow ,(string-join
30881 '("nosuid" "nodev" "loop"
30882 "encryption" "fsck" "nonempty"
30883 "allow_root" "allow_other")
30885 (mntoptions (@@ (require "nosuid,nodev")))
30886 (logout (@@ (wait "0")
30890 (mkmountpoint (@@ (enable "1")
30891 (remove "true")))))
30893 (service pam-mount-service-type
30894 (pam-mount-configuration
30895 (rules pam-mount-rules)))
30898 The complete list of possible options can be found in the man page for
30899 @uref{http://pam-mount.sourceforge.net/pam_mount.conf.5.html, pam_mount.conf}.
30904 @node Guix Services
30905 @subsection Guix Services
30907 @subsubheading Guix Build Coordinator
30908 The @uref{https://git.cbaines.net/guix/build-coordinator/,Guix Build
30909 Coordinator} aids in distributing derivation builds among machines
30910 running an @dfn{agent}. The build daemon is still used to build the
30911 derivations, but the Guix Build Coordinator manages allocating builds
30912 and working with the results.
30915 This service is considered experimental. Configuration options may be
30916 changed in a backwards-incompatible manner, and not all features have
30917 been thorougly tested.
30920 The Guix Build Coordinator consists of one @dfn{coordinator}, and one or
30921 more connected @dfn{agent} processes. The coordinator process handles
30922 clients submitting builds, and allocating builds to agents. The agent
30923 processes talk to a build daemon to actually perform the builds, then
30924 send the results back to the coordinator.
30926 There is a script to run the coordinator component of the Guix Build
30927 Coordinator, but the Guix service uses a custom Guile script instead, to
30928 provide better integration with G-expressions used in the configuration.
30930 @defvar {Scheme Variable} guix-build-coordinator-service-type
30931 Service type for the Guix Build Coordinator. Its value must be a
30932 @code{guix-build-coordinator-configuration} object.
30935 @deftp {Data Type} guix-build-coordinator-configuration
30936 Data type representing the configuration of the Guix Build Coordinator.
30939 @item @code{package} (default: @code{guix-build-coordinator})
30940 The Guix Build Coordinator package to use.
30942 @item @code{user} (default: @code{"guix-build-coordinator"})
30943 The system user to run the service as.
30945 @item @code{group} (default: @code{"guix-build-coordinator"})
30946 The system group to run the service as.
30948 @item @code{database-uri-string} (default: @code{"sqlite:///var/lib/guix-build-coordinator/guix_build_coordinator.db"})
30949 The URI to use for the database.
30951 @item @code{agent-communication-uri} (default: @code{"http://0.0.0.0:8745"})
30952 The URI describing how to listen to requests from agent processes.
30954 @item @code{client-communication-uri} (default: @code{"http://127.0.0.1:8746"})
30955 The URI describing how to listen to requests from clients. The client
30956 API allows submitting builds and currently isn't authenticated, so take
30957 care when configuring this value.
30959 @item @code{allocation-strategy} (default: @code{#~basic-build-allocation-strategy})
30960 A G-expression for the allocation strategy to be used. This is a
30961 procedure that takes the datastore as an argument and populates the
30962 allocation plan in the database.
30964 @item @code{hooks} (default: @var{'()})
30965 An association list of hooks. These provide a way to execute arbitrary
30966 code upon certain events, like a build result being processed.
30968 @item @code{guile} (default: @code{guile-3.0-latest})
30969 The Guile package with which to run the Guix Build Coordinator.
30974 @defvar {Scheme Variable} guix-build-coordinator-agent-service-type
30975 Service type for a Guix Build Coordinator agent. Its value must be a
30976 @code{guix-build-coordinator-agent-configuration} object.
30979 @deftp {Data Type} guix-build-coordinator-agent-configuration
30980 Data type representing the configuration a Guix Build Coordinator agent.
30983 @item @code{package} (default: @code{guix-build-coordinator})
30984 The Guix Build Coordinator package to use.
30986 @item @code{user} (default: @code{"guix-build-coordinator-agent"})
30987 The system user to run the service as.
30989 @item @code{coordinator} (default: @code{"http://localhost:8745"})
30990 The URI to use when connecting to the coordinator.
30992 @item @code{authentication}
30993 Record describing how this agent should authenticate with the
30994 coordinator. Possible record types are described below.
30996 @item @code{systems} (default: @code{#f})
30997 The systems for which this agent should fetch builds. The agent process
30998 will use the current system it's running on as the default.
31000 @item @code{max-parallel-builds} (default: @code{1})
31001 The number of builds to perform in parallel.
31003 @item @code{derivation-substitute-urls} (default: @code{#f})
31004 URLs from which to attempt to fetch substitutes for derivations, if the
31005 derivations aren't already available.
31007 @item @code{non-derivation-substitute-urls} (default: @code{#f})
31008 URLs from which to attempt to fetch substitutes for build inputs, if the
31009 input store items aren't already available.
31014 @deftp {Data Type} guix-build-coordinator-agent-password-auth
31015 Data type representing an agent authenticating with a coordinator via a
31020 The UUID of the agent. This should be generated by the coordinator
31021 process, stored in the coordinator database, and used by the intended
31024 @item @code{password}
31025 The password to use when connecting to the coordinator.
31030 @deftp {Data Type} guix-build-coordinator-agent-password-file-auth
31031 Data type representing an agent authenticating with a coordinator via a
31032 UUID and password read from a file.
31036 The UUID of the agent. This should be generated by the coordinator
31037 process, stored in the coordinator database, and used by the intended
31040 @item @code{password-file}
31041 A file containing the password to use when connecting to the
31047 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth
31048 Data type representing an agent authenticating with a coordinator via a
31049 dyanmic auth token and agent name.
31052 @item @code{agent-name}
31053 Name of an agent, this is used to match up to an existing entry in the
31054 database if there is one. When no existing entry is found, a new entry
31055 is automatically added.
31058 Dynamic auth token, this is created and stored in the coordinator
31059 database, and is used by the agent to authenticate.
31064 @deftp {Data Type} guix-build-coordinator-agent-dynamic-auth-with-file
31065 Data type representing an agent authenticating with a coordinator via a
31066 dyanmic auth token read from a file and agent name.
31069 @item @code{agent-name}
31070 Name of an agent, this is used to match up to an existing entry in the
31071 database if there is one. When no existing entry is found, a new entry
31072 is automatically added.
31074 @item @code{token-file}
31075 File containing the dynamic auth token, this is created and stored in
31076 the coordinator database, and is used by the agent to authenticate.
31081 The Guix Build Coordinator package contains a script to query an
31082 instance of the Guix Data Service for derivations to build, and then
31083 submit builds for those derivations to the coordinator. The service
31084 type below assists in running this script. This is an additional tool
31085 that may be useful when building derivations contained within an
31086 instance of the Guix Data Service.
31088 @defvar {Scheme Variable} guix-build-coordinator-queue-builds-service-type
31089 Service type for the
31090 guix-build-coordinator-queue-builds-from-guix-data-service script. Its
31091 value must be a @code{guix-build-coordinator-queue-builds-configuration}
31095 @deftp {Data Type} guix-build-coordinator-queue-builds-configuration
31096 Data type representing the options to the queue builds from guix data
31100 @item @code{package} (default: @code{guix-build-coordinator})
31101 The Guix Build Coordinator package to use.
31103 @item @code{user} (default: @code{"guix-build-coordinator-queue-builds"})
31104 The system user to run the service as.
31106 @item @code{coordinator} (default: @code{"http://localhost:8745"})
31107 The URI to use when connecting to the coordinator.
31109 @item @code{systems} (default: @code{#f})
31110 The systems for which to fetch derivations to build.
31112 @item @code{systems-and-targets} (default: @code{#f})
31113 An association list of system and target pairs for which to fetch
31114 derivations to build.
31116 @item @code{guix-data-service} (default: @code{"https://data.guix.gnu.org"})
31117 The Guix Data Service instance from which to query to find out about
31118 derivations to build.
31120 @item @code{processed-commits-file} (default: @code{"/var/cache/guix-build-coordinator-queue-builds/processed-commits"})
31121 A file to record which commits have been processed, to avoid needlessly
31122 processing them again if the service is restarted.
31127 @subsubheading Guix Data Service
31128 The @uref{http://data.guix.gnu.org,Guix Data Service} processes, stores
31129 and provides data about GNU Guix. This includes information about
31130 packages, derivations and lint warnings.
31132 The data is stored in a PostgreSQL database, and available through a web
31135 @defvar {Scheme Variable} guix-data-service-type
31136 Service type for the Guix Data Service. Its value must be a
31137 @code{guix-data-service-configuration} object. The service optionally
31138 extends the getmail service, as the guix-commits mailing list is used to
31139 find out about changes in the Guix git repository.
31142 @deftp {Data Type} guix-data-service-configuration
31143 Data type representing the configuration of the Guix Data Service.
31146 @item @code{package} (default: @code{guix-data-service})
31147 The Guix Data Service package to use.
31149 @item @code{user} (default: @code{"guix-data-service"})
31150 The system user to run the service as.
31152 @item @code{group} (default: @code{"guix-data-service"})
31153 The system group to run the service as.
31155 @item @code{port} (default: @code{8765})
31156 The port to bind the web service to.
31158 @item @code{host} (default: @code{"127.0.0.1"})
31159 The host to bind the web service to.
31161 @item @code{getmail-idle-mailboxes} (default: @code{#f})
31162 If set, this is the list of mailboxes that the getmail service will be
31163 configured to listen to.
31165 @item @code{commits-getmail-retriever-configuration} (default: @code{#f})
31166 If set, this is the @code{getmail-retriever-configuration} object with
31167 which to configure getmail to fetch mail from the guix-commits mailing
31170 @item @code{extra-options} (default: @var{'()})
31171 Extra command line options for @code{guix-data-service}.
31173 @item @code{extra-process-jobs-options} (default: @var{'()})
31174 Extra command line options for @code{guix-data-service-process-jobs}.
31179 @node Linux Services
31180 @subsection Linux Services
31183 @cindex out of memory killer
31185 @cindex early out of memory daemon
31186 @subsubheading Early OOM Service
31188 @uref{https://github.com/rfjakob/earlyoom,Early OOM}, also known as
31189 Earlyoom, is a minimalist out of memory (OOM) daemon that runs in user
31190 space and provides a more responsive and configurable alternative to the
31191 in-kernel OOM killer. It is useful to prevent the system from becoming
31192 unresponsive when it runs out of memory.
31194 @deffn {Scheme Variable} earlyoom-service-type
31195 The service type for running @command{earlyoom}, the Early OOM daemon.
31196 Its value must be a @code{earlyoom-configuration} object, described
31197 below. The service can be instantiated in its default configuration
31201 (service earlyoom-service-type)
31205 @deftp {Data Type} earlyoom-configuration
31206 This is the configuration record for the @code{earlyoom-service-type}.
31209 @item @code{earlyoom} (default: @var{earlyoom})
31210 The Earlyoom package to use.
31212 @item @code{minimum-available-memory} (default: @code{10})
31213 The threshold for the minimum @emph{available} memory, in percentages.
31215 @item @code{minimum-free-swap} (default: @code{10})
31216 The threshold for the minimum free swap memory, in percentages.
31218 @item @code{prefer-regexp} (default: @code{#f})
31219 A regular expression (as a string) to match the names of the processes
31220 that should be preferably killed.
31222 @item @code{avoid-regexp} (default: @code{#f})
31223 A regular expression (as a string) to match the names of the processes
31224 that should @emph{not} be killed.
31226 @item @code{memory-report-interval} (default: @code{0})
31227 The interval in seconds at which a memory report is printed. It is
31228 disabled by default.
31230 @item @code{ignore-positive-oom-score-adj?} (default: @code{#f})
31231 A boolean indicating whether the positive adjustments set in
31232 @file{/proc/*/oom_score_adj} should be ignored.
31234 @item @code{show-debug-messages?} (default: @code{#f})
31235 A boolean indicating whether debug messages should be printed. The logs
31236 are saved at @file{/var/log/earlyoom.log}.
31238 @item @code{send-notification-command} (default: @code{#f})
31239 This can be used to provide a custom command used for sending
31245 @cindex kernel module loader
31246 @subsubheading Kernel Module Loader Service
31248 The kernel module loader service allows one to load loadable kernel
31249 modules at boot. This is especially useful for modules that don't
31250 autoload and need to be manually loaded, as it's the case with
31253 @deffn {Scheme Variable} kernel-module-loader-service-type
31254 The service type for loading loadable kernel modules at boot with
31255 @command{modprobe}. Its value must be a list of strings representing
31256 module names. For example loading the drivers provided by
31257 @code{ddcci-driver-linux}, in debugging mode by passing some module
31258 parameters, can be done as follow:
31261 (use-modules (gnu) (gnu services))
31262 (use-package-modules linux)
31263 (use-service-modules linux)
31265 (define ddcci-config
31266 (plain-file "ddcci.conf"
31267 "options ddcci dyndbg delay=120"))
31271 (services (cons* (service kernel-module-loader-service-type
31272 '("ddcci" "ddcci_backlight"))
31273 (simple-service 'ddcci-config etc-service-type
31274 (list `("modprobe.d/ddcci.conf"
31277 (kernel-loadable-modules (list ddcci-driver-linux)))
31282 @cindex compressed swap
31283 @cindex Compressed RAM-based block devices
31284 @subsubheading Zram Device Service
31286 The Zram device service provides a compressed swap device in system
31287 memory. The Linux Kernel documentation has more information about
31288 @uref{https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html,zram}
31291 @deffn {Scheme Variable} zram-device-service-type
31292 This service creates the zram block device, formats it as swap and
31293 enables it as a swap device. The service's value is a
31294 @code{zram-device-configuration} record.
31296 @deftp {Data Type} zram-device-configuration
31297 This is the data type representing the configuration for the zram-device
31301 @item @code{size} (default @code{"1G"})
31302 This is the amount of space you wish to provide for the zram device. It
31303 accepts a string and can be a number of bytes or use a suffix, eg.:
31304 @code{"512M"} or @code{1024000}.
31305 @item @code{compression-algorithm} (default @code{'lzo})
31306 This is the compression algorithm you wish to use. It is difficult to
31307 list all the possible compression options, but common ones supported by
31308 Guix's Linux Libre Kernel include @code{'lzo}, @code{'lz4} and @code{'zstd}.
31309 @item @code{memory-limit} (default @code{0})
31310 This is the maximum amount of memory which the zram device can use.
31311 Setting it to '0' disables the limit. While it is generally expected
31312 that compression will be 2:1, it is possible that uncompressable data
31313 can be written to swap and this is a method to limit how much memory can
31314 be used. It accepts a string and can be a number of bytes or use a
31315 suffix, eg.: @code{"2G"}.
31316 @item @code{priority} (default @code{-1})
31317 This is the priority of the swap device created from the zram device.
31318 @code{swapon} accepts values between -1 and 32767, with higher values
31319 indicating higher priority. Higher priority swap will generally be used
31326 @node Hurd Services
31327 @subsection Hurd Services
31329 @defvr {Scheme Variable} hurd-console-service-type
31330 This service starts the fancy @code{VGA} console client on the Hurd.
31332 The service's value is a @code{hurd-console-configuration} record.
31335 @deftp {Data Type} hurd-console-configuration
31336 This is the data type representing the configuration for the
31337 hurd-console-service.
31340 @item @code{hurd} (default: @var{hurd})
31341 The Hurd package to use.
31345 @defvr {Scheme Variable} hurd-getty-service-type
31346 This service starts a tty using the Hurd @code{getty} program.
31348 The service's value is a @code{hurd-getty-configuration} record.
31351 @deftp {Data Type} hurd-getty-configuration
31352 This is the data type representing the configuration for the
31353 hurd-getty-service.
31356 @item @code{hurd} (default: @var{hurd})
31357 The Hurd package to use.
31360 The name of the console this Getty runs on---e.g., @code{"tty1"}.
31362 @item @code{baud-rate} (default: @code{38400})
31363 An integer specifying the baud rate of the tty.
31368 @node Miscellaneous Services
31369 @subsection Miscellaneous Services
31371 @cindex fingerprint
31372 @subsubheading Fingerprint Service
31374 The @code{(gnu services authentication)} module provides a DBus service to
31375 read and identify fingerprints via a fingerprint sensor.
31377 @defvr {Scheme Variable} fprintd-service-type
31378 The service type for @command{fprintd}, which provides the fingerprint
31379 reading capability.
31382 (service fprintd-service-type)
31387 @subsubheading System Control Service
31389 The @code{(gnu services sysctl)} provides a service to configure kernel
31390 parameters at boot.
31392 @defvr {Scheme Variable} sysctl-service-type
31393 The service type for @command{sysctl}, which modifies kernel parameters
31394 under @file{/proc/sys/}. To enable IPv4 forwarding, it can be
31398 (service sysctl-service-type
31399 (sysctl-configuration
31400 (settings '(("net.ipv4.ip_forward" . "1")))))
31403 Since @code{sysctl-service-type} is used in the default lists of
31404 services, @code{%base-services} and @code{%desktop-services}, you can
31405 use @code{modify-services} to change its configuration and add the
31406 kernel parameters that you want (@pxref{Service Reference,
31407 @code{modify-services}}).
31410 (modify-services %base-services
31411 (sysctl-service-type config =>
31412 (sysctl-configuration
31413 (settings (append '(("net.ipv4.ip_forward" . "1"))
31414 %default-sysctl-settings)))))
31419 @deftp {Data Type} sysctl-configuration
31420 The data type representing the configuration of @command{sysctl}.
31423 @item @code{sysctl} (default: @code{(file-append procps "/sbin/sysctl"})
31424 The @command{sysctl} executable to use.
31426 @item @code{settings} (default: @code{%default-sysctl-settings})
31427 An association list specifies kernel parameters and their values.
31431 @defvr {Scheme Variable} %default-sysctl-settings
31432 An association list specifying the default @command{sysctl} parameters
31437 @subsubheading PC/SC Smart Card Daemon Service
31439 The @code{(gnu services security-token)} module provides the following service
31440 to run @command{pcscd}, the PC/SC Smart Card Daemon. @command{pcscd} is the
31441 daemon program for pcsc-lite and the MuscleCard framework. It is a resource
31442 manager that coordinates communications with smart card readers, smart cards
31443 and cryptographic tokens that are connected to the system.
31445 @defvr {Scheme Variable} pcscd-service-type
31446 Service type for the @command{pcscd} service. Its value must be a
31447 @code{pcscd-configuration} object. To run pcscd in the default
31448 configuration, instantiate it as:
31451 (service pcscd-service-type)
31455 @deftp {Data Type} pcscd-configuration
31456 The data type representing the configuration of @command{pcscd}.
31459 @item @code{pcsc-lite} (default: @code{pcsc-lite})
31460 The pcsc-lite package that provides pcscd.
31461 @item @code{usb-drivers} (default: @code{(list ccid)})
31462 List of packages that provide USB drivers to pcscd. Drivers are expected to be
31463 under @file{pcsc/drivers} in the store directory of the package.
31468 @subsubheading Lirc Service
31470 The @code{(gnu services lirc)} module provides the following service.
31472 @deffn {Scheme Procedure} lirc-service [#:lirc lirc] @
31473 [#:device #f] [#:driver #f] [#:config-file #f] @
31474 [#:extra-options '()]
31475 Return a service that runs @url{http://www.lirc.org,LIRC}, a daemon that
31476 decodes infrared signals from remote controls.
31478 Optionally, @var{device}, @var{driver} and @var{config-file}
31479 (configuration file name) may be specified. See @command{lircd} manual
31482 Finally, @var{extra-options} is a list of additional command-line options
31483 passed to @command{lircd}.
31487 @subsubheading Spice Service
31489 The @code{(gnu services spice)} module provides the following service.
31491 @deffn {Scheme Procedure} spice-vdagent-service [#:spice-vdagent]
31492 Returns a service that runs @url{https://www.spice-space.org,VDAGENT}, a daemon
31493 that enables sharing the clipboard with a vm and setting the guest display
31494 resolution when the graphical console window resizes.
31497 @cindex inputattach
31498 @subsubheading inputattach Service
31500 @cindex tablet input, for Xorg
31501 @cindex touchscreen input, for Xorg
31502 The @uref{https://linuxwacom.github.io/, inputattach} service allows you to
31503 use input devices such as Wacom tablets, touchscreens, or joysticks with the
31504 Xorg display server.
31506 @deffn {Scheme Variable} inputattach-service-type
31507 Type of a service that runs @command{inputattach} on a device and
31508 dispatches events from it.
31511 @deftp {Data Type} inputattach-configuration
31513 @item @code{device-type} (default: @code{"wacom"})
31514 The type of device to connect to. Run @command{inputattach --help}, from the
31515 @code{inputattach} package, to see the list of supported device types.
31517 @item @code{device} (default: @code{"/dev/ttyS0"})
31518 The device file to connect to the device.
31520 @item @code{baud-rate} (default: @code{#f})
31521 Baud rate to use for the serial connection.
31522 Should be a number or @code{#f}.
31524 @item @code{log-file} (default: @code{#f})
31525 If true, this must be the name of a file to log messages to.
31529 @subsubheading Dictionary Service
31531 The @code{(gnu services dict)} module provides the following service:
31533 @defvr {Scheme Variable} dicod-service-type
31534 This is the type of the service that runs the @command{dicod} daemon, an
31535 implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
31538 @deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
31539 Return a service that runs the @command{dicod} daemon, an implementation
31540 of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
31542 The optional @var{config} argument specifies the configuration for
31543 @command{dicod}, which should be a @code{<dicod-configuration>} object, by
31544 default it serves the GNU Collaborative International Dictionary of English.
31546 You can add @command{open localhost} to your @file{~/.dico} file to make
31547 @code{localhost} the default server for @command{dico} client
31548 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
31551 @deftp {Data Type} dicod-configuration
31552 Data type representing the configuration of dicod.
31555 @item @code{dico} (default: @var{dico})
31556 Package object of the GNU Dico dictionary server.
31558 @item @code{interfaces} (default: @var{'("localhost")})
31559 This is the list of IP addresses and ports and possibly socket file
31560 names to listen to (@pxref{Server Settings, @code{listen} directive,,
31561 dico, GNU Dico Manual}).
31563 @item @code{handlers} (default: @var{'()})
31564 List of @code{<dicod-handler>} objects denoting handlers (module instances).
31566 @item @code{databases} (default: @var{(list %dicod-database:gcide)})
31567 List of @code{<dicod-database>} objects denoting dictionaries to be served.
31571 @deftp {Data Type} dicod-handler
31572 Data type representing a dictionary handler (module instance).
31576 Name of the handler (module instance).
31578 @item @code{module} (default: @var{#f})
31579 Name of the dicod module of the handler (instance). If it is @code{#f},
31580 the module has the same name as the handler.
31581 (@pxref{Modules,,, dico, GNU Dico Manual}).
31583 @item @code{options}
31584 List of strings or gexps representing the arguments for the module handler
31588 @deftp {Data Type} dicod-database
31589 Data type representing a dictionary database.
31593 Name of the database, will be used in DICT commands.
31595 @item @code{handler}
31596 Name of the dicod handler (module instance) used by this database
31597 (@pxref{Handlers,,, dico, GNU Dico Manual}).
31599 @item @code{complex?} (default: @var{#f})
31600 Whether the database configuration complex. The complex configuration
31601 will need a corresponding @code{<dicod-handler>} object, otherwise not.
31603 @item @code{options}
31604 List of strings or gexps representing the arguments for the database
31605 (@pxref{Databases,,, dico, GNU Dico Manual}).
31609 @defvr {Scheme Variable} %dicod-database:gcide
31610 A @code{<dicod-database>} object serving the GNU Collaborative International
31611 Dictionary of English using the @code{gcide} package.
31614 The following is an example @code{dicod-service} configuration.
31617 (dicod-service #:config
31618 (dicod-configuration
31619 (handlers (list (dicod-handler
31623 (list #~(string-append "dbdir=" #$wordnet))))))
31624 (databases (list (dicod-database
31627 (handler "wordnet")
31628 (options '("database=wn")))
31629 %dicod-database:gcide))))
31633 @subsubheading Docker Service
31635 The @code{(gnu services docker)} module provides the following services.
31637 @defvr {Scheme Variable} docker-service-type
31639 This is the type of the service that runs @url{https://www.docker.com,Docker},
31640 a daemon that can execute application bundles (sometimes referred to as
31641 ``containers'') in isolated environments.
31645 @deftp {Data Type} docker-configuration
31646 This is the data type representing the configuration of Docker and Containerd.
31650 @item @code{package} (default: @code{docker})
31651 The Docker daemon package to use.
31653 @item @code{package} (default: @code{docker-cli})
31654 The Docker client package to use.
31656 @item @code{containerd} (default: @var{containerd})
31657 The Containerd package to use.
31659 @item @code{proxy} (default @var{docker-libnetwork-cmd-proxy})
31660 The Docker user-land networking proxy package to use.
31662 @item @code{enable-proxy?} (default @code{#t})
31663 Enable or disable the use of the Docker user-land networking proxy.
31665 @item @code{debug?} (default @code{#f})
31666 Enable or disable debug output.
31668 @item @code{enable-iptables?} (default @code{#t})
31669 Enable or disable the addition of iptables rules.
31674 @cindex Singularity, container service
31675 @defvr {Scheme Variable} singularity-service-type
31676 This is the type of the service that allows you to run
31677 @url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
31678 create and run application bundles (aka. ``containers''). The value for this
31679 service is the Singularity package to use.
31681 The service does not install a daemon; instead, it installs helper programs as
31682 setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
31683 @command{singularity run} and similar commands.
31687 @subsubheading Auditd Service
31689 The @code{(gnu services auditd)} module provides the following service.
31691 @defvr {Scheme Variable} auditd-service-type
31693 This is the type of the service that runs
31694 @url{https://people.redhat.com/sgrubb/audit/,auditd},
31695 a daemon that tracks security-relevant information on your system.
31697 Examples of things that can be tracked:
31707 Failed login attempts
31714 @command{auditctl} from the @code{audit} package can be used in order
31715 to add or remove events to be tracked (until the next reboot).
31716 In order to permanently track events, put the command line arguments
31717 of auditctl into a file called @code{audit.rules} in the configuration
31718 directory (see below).
31719 @command{aureport} from the @code{audit} package can be used in order
31720 to view a report of all recorded events.
31721 The audit daemon by default logs into the file
31722 @file{/var/log/audit.log}.
31726 @deftp {Data Type} auditd-configuration
31727 This is the data type representing the configuration of auditd.
31731 @item @code{audit} (default: @code{audit})
31732 The audit package to use.
31734 @item @code{configuration-directory} (default: @code{%default-auditd-configuration-directory})
31735 The directory containing the configuration file for the audit package, which
31736 must be named @code{auditd.conf}, and optionally some audit rules to
31737 instantiate on startup.
31743 @subsubheading R-Shiny service
31745 The @code{(gnu services science)} module provides the following service.
31747 @defvr {Scheme Variable} rshiny-service-type
31749 This is a type of service which is used to run a webapp created with
31750 @code{r-shiny}. This service sets the @env{R_LIBS_USER} environment
31751 variable and runs the provided script to call @code{runApp}.
31753 @deftp {Data Type} rshiny-configuration
31754 This is the data type representing the configuration of rshiny.
31758 @item @code{package} (default: @code{r-shiny})
31759 The package to use.
31761 @item @code{binary} (defaunlt @code{"rshiny"})
31762 The name of the binary or shell script located at @code{package/bin/} to
31763 run when the service is run.
31765 The common way to create this file is as follows:
31769 (let* ((out (assoc-ref %outputs "out"))
31770 (targetdir (string-append out "/share/" ,name))
31771 (app (string-append out "/bin/" ,name))
31772 (Rbin (string-append (assoc-ref %build-inputs "r-min")
31775 (mkdir-p (string-append out "/bin"))
31776 (call-with-output-file app
31782 runApp(launch.browser=0, port=4202)~%\n"
31791 @subsubheading Nix service
31793 The @code{(gnu services nix)} module provides the following service.
31795 @defvr {Scheme Variable} nix-service-type
31797 This is the type of the service that runs build daemon of the
31798 @url{https://nixos.org/nix/, Nix} package manager. Here is an example showing
31802 (use-modules (gnu))
31803 (use-service-modules nix)
31804 (use-package-modules package-management)
31808 (packages (append (list nix)
31811 (services (append (list (service nix-service-type))
31815 After @command{guix system reconfigure} configure Nix for your user:
31818 @item Add a Nix channel and update it. See
31819 @url{https://nixos.org/nix/manual/, Nix Package Manager Guide}.
31821 @item Create a symlink to your profile and activate Nix profile:
31825 $ ln -s "/nix/var/nix/profiles/per-user/$USER/profile" ~/.nix-profile
31826 $ source /run/current-system/profile/etc/profile.d/nix.sh
31831 @deftp {Data Type} nix-configuration
31832 This data type represents the configuration of the Nix daemon.
31835 @item @code{nix} (default: @code{nix})
31836 The Nix package to use.
31838 @item @code{sandbox} (default: @code{#t})
31839 Specifies whether builds are sandboxed by default.
31841 @item @code{build-sandbox-items} (default: @code{'()})
31842 This is a list of strings or objects appended to the
31843 @code{build-sandbox-items} field of the configuration file.
31845 @item @code{extra-config} (default: @code{'()})
31846 This is a list of strings or objects appended to the configuration file.
31847 It is used to pass extra text to be added verbatim to the configuration
31850 @item @code{extra-options} (default: @code{'()})
31851 Extra command line options for @code{nix-service-type}.
31855 @node Setuid Programs
31856 @section Setuid Programs
31858 @cindex setuid programs
31859 Some programs need to run with ``root'' privileges, even when they are
31860 launched by unprivileged users. A notorious example is the
31861 @command{passwd} program, which users can run to change their
31862 password, and which needs to access the @file{/etc/passwd} and
31863 @file{/etc/shadow} files---something normally restricted to root, for
31864 obvious security reasons. To address that, these executables are
31865 @dfn{setuid-root}, meaning that they always run with root privileges
31866 (@pxref{How Change Persona,,, libc, The GNU C Library Reference Manual},
31867 for more info about the setuid mechanism).
31869 The store itself @emph{cannot} contain setuid programs: that would be a
31870 security issue since any user on the system can write derivations that
31871 populate the store (@pxref{The Store}). Thus, a different mechanism is
31872 used: instead of changing the setuid bit directly on files that are in
31873 the store, we let the system administrator @emph{declare} which programs
31874 should be setuid root.
31876 The @code{setuid-programs} field of an @code{operating-system}
31877 declaration contains a list of G-expressions denoting the names of
31878 programs to be setuid-root (@pxref{Using the Configuration System}).
31879 For instance, the @command{passwd} program, which is part of the Shadow
31880 package, can be designated by this G-expression (@pxref{G-Expressions}):
31883 #~(string-append #$shadow "/bin/passwd")
31886 A default set of setuid programs is defined by the
31887 @code{%setuid-programs} variable of the @code{(gnu system)} module.
31889 @defvr {Scheme Variable} %setuid-programs
31890 A list of G-expressions denoting common programs that are setuid-root.
31892 The list includes commands such as @command{passwd}, @command{ping},
31893 @command{su}, and @command{sudo}.
31896 Under the hood, the actual setuid programs are created in the
31897 @file{/run/setuid-programs} directory at system activation time. The
31898 files in this directory refer to the ``real'' binaries, which are in the
31901 @node X.509 Certificates
31902 @section X.509 Certificates
31904 @cindex HTTPS, certificates
31905 @cindex X.509 certificates
31907 Web servers available over HTTPS (that is, HTTP over the transport-layer
31908 security mechanism, TLS) send client programs an @dfn{X.509 certificate}
31909 that the client can then use to @emph{authenticate} the server. To do
31910 that, clients verify that the server's certificate is signed by a
31911 so-called @dfn{certificate authority} (CA). But to verify the CA's
31912 signature, clients must have first acquired the CA's certificate.
31914 Web browsers such as GNU@tie{}IceCat include their own set of CA
31915 certificates, such that they are able to verify CA signatures
31918 However, most other programs that can talk HTTPS---@command{wget},
31919 @command{git}, @command{w3m}, etc.---need to be told where CA
31920 certificates can be found.
31922 @cindex @code{nss-certs}
31923 In Guix, this is done by adding a package that provides certificates
31924 to the @code{packages} field of the @code{operating-system} declaration
31925 (@pxref{operating-system Reference}). Guix includes one such package,
31926 @code{nss-certs}, which is a set of CA certificates provided as part of
31927 Mozilla's Network Security Services.
31929 Note that it is @emph{not} part of @code{%base-packages}, so you need to
31930 explicitly add it. The @file{/etc/ssl/certs} directory, which is where
31931 most applications and libraries look for certificates by default, points
31932 to the certificates installed globally.
31934 Unprivileged users, including users of Guix on a foreign distro,
31935 can also install their own certificate package in
31936 their profile. A number of environment variables need to be defined so
31937 that applications and libraries know where to find them. Namely, the
31938 OpenSSL library honors the @env{SSL_CERT_DIR} and @env{SSL_CERT_FILE}
31939 variables. Some applications add their own environment variables; for
31940 instance, the Git version control system honors the certificate bundle
31941 pointed to by the @env{GIT_SSL_CAINFO} environment variable. Thus, you
31942 would typically run something like:
31945 guix install nss-certs
31946 export SSL_CERT_DIR="$HOME/.guix-profile/etc/ssl/certs"
31947 export SSL_CERT_FILE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
31948 export GIT_SSL_CAINFO="$SSL_CERT_FILE"
31951 As another example, R requires the @env{CURL_CA_BUNDLE} environment
31952 variable to point to a certificate bundle, so you would have to run
31953 something like this:
31956 guix install nss-certs
31957 export CURL_CA_BUNDLE="$HOME/.guix-profile/etc/ssl/certs/ca-certificates.crt"
31960 For other applications you may want to look up the required environment
31961 variable in the relevant documentation.
31964 @node Name Service Switch
31965 @section Name Service Switch
31967 @cindex name service switch
31969 The @code{(gnu system nss)} module provides bindings to the
31970 configuration file of the libc @dfn{name service switch} or @dfn{NSS}
31971 (@pxref{NSS Configuration File,,, libc, The GNU C Library Reference
31972 Manual}). In a nutshell, the NSS is a mechanism that allows libc to be
31973 extended with new ``name'' lookup methods for system databases, which
31974 includes host names, service names, user accounts, and more (@pxref{Name
31975 Service Switch, System Databases and Name Service Switch,, libc, The GNU
31976 C Library Reference Manual}).
31978 The NSS configuration specifies, for each system database, which lookup
31979 method is to be used, and how the various methods are chained
31980 together---for instance, under which circumstances NSS should try the
31981 next method in the list. The NSS configuration is given in the
31982 @code{name-service-switch} field of @code{operating-system} declarations
31983 (@pxref{operating-system Reference, @code{name-service-switch}}).
31986 @cindex .local, host name lookup
31987 As an example, the declaration below configures the NSS to use the
31988 @uref{https://0pointer.de/lennart/projects/nss-mdns/, @code{nss-mdns}
31989 back-end}, which supports host name lookups over multicast DNS (mDNS)
31990 for host names ending in @code{.local}:
31993 (name-service-switch
31994 (hosts (list %files ;first, check /etc/hosts
31996 ;; If the above did not succeed, try
31997 ;; with 'mdns_minimal'.
31999 (name "mdns_minimal")
32001 ;; 'mdns_minimal' is authoritative for
32002 ;; '.local'. When it returns "not found",
32003 ;; no need to try the next methods.
32004 (reaction (lookup-specification
32005 (not-found => return))))
32007 ;; Then fall back to DNS.
32011 ;; Finally, try with the "full" 'mdns'.
32016 Do not worry: the @code{%mdns-host-lookup-nss} variable (see below)
32017 contains this configuration, so you will not have to type it if all you
32018 want is to have @code{.local} host lookup working.
32020 Note that, in this case, in addition to setting the
32021 @code{name-service-switch} of the @code{operating-system} declaration,
32022 you also need to use @code{avahi-service-type} (@pxref{Networking Services,
32023 @code{avahi-service-type}}), or @code{%desktop-services}, which includes it
32024 (@pxref{Desktop Services}). Doing this makes @code{nss-mdns} accessible
32025 to the name service cache daemon (@pxref{Base Services,
32026 @code{nscd-service}}).
32028 For convenience, the following variables provide typical NSS
32031 @defvr {Scheme Variable} %default-nss
32032 This is the default name service switch configuration, a
32033 @code{name-service-switch} object.
32036 @defvr {Scheme Variable} %mdns-host-lookup-nss
32037 This is the name service switch configuration with support for host name
32038 lookup over multicast DNS (mDNS) for host names ending in @code{.local}.
32041 The reference for name service switch configuration is given below. It
32042 is a direct mapping of the configuration file format of the C library , so
32043 please refer to the C library manual for more information (@pxref{NSS
32044 Configuration File,,, libc, The GNU C Library Reference Manual}).
32045 Compared to the configuration file format of libc NSS, it has the advantage
32046 not only of adding this warm parenthetic feel that we like, but also
32047 static checks: you will know about syntax errors and typos as soon as you
32048 run @command{guix system}.
32050 @deftp {Data Type} name-service-switch
32052 This is the data type representation the configuration of libc's name
32053 service switch (NSS). Each field below represents one of the supported
32070 The system databases handled by the NSS@. Each of these fields must be a
32071 list of @code{<name-service>} objects (see below).
32075 @deftp {Data Type} name-service
32077 This is the data type representing an actual name service and the
32078 associated lookup action.
32082 A string denoting the name service (@pxref{Services in the NSS
32083 configuration,,, libc, The GNU C Library Reference Manual}).
32085 Note that name services listed here must be visible to nscd. This is
32086 achieved by passing the @code{#:name-services} argument to
32087 @code{nscd-service} the list of packages providing the needed name
32088 services (@pxref{Base Services, @code{nscd-service}}).
32091 An action specified using the @code{lookup-specification} macro
32092 (@pxref{Actions in the NSS configuration,,, libc, The GNU C Library
32093 Reference Manual}). For example:
32096 (lookup-specification (unavailable => continue)
32097 (success => return))
32102 @node Initial RAM Disk
32103 @section Initial RAM Disk
32106 @cindex initial RAM disk
32107 For bootstrapping purposes, the Linux-Libre kernel is passed an
32108 @dfn{initial RAM disk}, or @dfn{initrd}. An initrd contains a temporary
32109 root file system as well as an initialization script. The latter is
32110 responsible for mounting the real root file system, and for loading any
32111 kernel modules that may be needed to achieve that.
32113 The @code{initrd-modules} field of an @code{operating-system}
32114 declaration allows you to specify Linux-libre kernel modules that must
32115 be available in the initrd. In particular, this is where you would list
32116 modules needed to actually drive the hard disk where your root partition
32117 is---although the default value of @code{initrd-modules} should cover
32118 most use cases. For example, assuming you need the @code{megaraid_sas}
32119 module in addition to the default modules to be able to access your root
32120 file system, you would write:
32125 (initrd-modules (cons "megaraid_sas" %base-initrd-modules)))
32128 @defvr {Scheme Variable} %base-initrd-modules
32129 This is the list of kernel modules included in the initrd by default.
32132 Furthermore, if you need lower-level customization, the @code{initrd}
32133 field of an @code{operating-system} declaration allows
32134 you to specify which initrd you would like to use. The @code{(gnu
32135 system linux-initrd)} module provides three ways to build an initrd: the
32136 high-level @code{base-initrd} procedure and the low-level
32137 @code{raw-initrd} and @code{expression->initrd} procedures.
32139 The @code{base-initrd} procedure is intended to cover most common uses.
32140 For example, if you want to add a bunch of kernel modules to be loaded
32141 at boot time, you can define the @code{initrd} field of the operating
32142 system declaration like this:
32145 (initrd (lambda (file-systems . rest)
32146 ;; Create a standard initrd but set up networking
32147 ;; with the parameters QEMU expects by default.
32148 (apply base-initrd file-systems
32149 #:qemu-networking? #t
32153 The @code{base-initrd} procedure also handles common use cases that
32154 involves using the system as a QEMU guest, or as a ``live'' system with
32155 volatile root file system.
32157 The @code{base-initrd} procedure is built from @code{raw-initrd} procedure.
32158 Unlike @code{base-initrd}, @code{raw-initrd} doesn't do anything high-level,
32159 such as trying to guess which kernel modules and packages should be included
32160 to the initrd. An example use of @code{raw-initrd} is when a user has
32161 a custom Linux kernel configuration and default kernel modules included by
32162 @code{base-initrd} are not available.
32164 The initial RAM disk produced by @code{base-initrd} or @code{raw-initrd}
32165 honors several options passed on the Linux kernel command line
32166 (that is, arguments passed @i{via} the @code{linux} command of GRUB, or the
32167 @code{-append} option of QEMU), notably:
32170 @item --load=@var{boot}
32171 Tell the initial RAM disk to load @var{boot}, a file containing a Scheme
32172 program, once it has mounted the root file system.
32174 Guix uses this option to yield control to a boot program that runs the
32175 service activation programs and then spawns the GNU@tie{}Shepherd, the
32176 initialization system.
32178 @item --root=@var{root}
32179 Mount @var{root} as the root file system. @var{root} can be a device
32180 name like @code{/dev/sda1}, a file system label, or a file system UUID.
32181 When unspecified, the device name from the root file system of the
32182 operating system declaration is used.
32184 @item --system=@var{system}
32185 Have @file{/run/booted-system} and @file{/run/current-system} point to
32188 @item modprobe.blacklist=@var{modules}@dots{}
32189 @cindex module, black-listing
32190 @cindex black list, of kernel modules
32191 Instruct the initial RAM disk as well as the @command{modprobe} command
32192 (from the kmod package) to refuse to load @var{modules}. @var{modules}
32193 must be a comma-separated list of module names---e.g.,
32194 @code{usbkbd,9pnet}.
32197 Start a read-eval-print loop (REPL) from the initial RAM disk before it
32198 tries to load kernel modules and to mount the root file system. Our
32199 marketing team calls it @dfn{boot-to-Guile}. The Schemer in you will
32200 love it. @xref{Using Guile Interactively,,, guile, GNU Guile Reference
32201 Manual}, for more information on Guile's REPL.
32205 Now that you know all the features that initial RAM disks produced by
32206 @code{base-initrd} and @code{raw-initrd} provide,
32207 here is how to use it and customize it further.
32210 @cindex initial RAM disk
32211 @deffn {Scheme Procedure} raw-initrd @var{file-systems} @
32212 [#:linux-modules '()] [#:mapped-devices '()] @
32213 [#:keyboard-layout #f] @
32214 [#:helper-packages '()] [#:qemu-networking? #f] [#:volatile-root? #f]
32215 Return a derivation that builds a raw initrd. @var{file-systems} is
32216 a list of file systems to be mounted by the initrd, possibly in addition to
32217 the root file system specified on the kernel command line via @option{--root}.
32218 @var{linux-modules} is a list of kernel modules to be loaded at boot time.
32219 @var{mapped-devices} is a list of device mappings to realize before
32220 @var{file-systems} are mounted (@pxref{Mapped Devices}).
32221 @var{helper-packages} is a list of packages to be copied in the initrd.
32223 include @code{e2fsck/static} or other packages needed by the initrd to check
32224 the root file system.
32226 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
32227 the desired console keyboard layout. This is done before @var{mapped-devices}
32228 are set up and before @var{file-systems} are mounted such that, should the
32229 user need to enter a passphrase or use the REPL, this happens using the
32230 intended keyboard layout.
32232 When @var{qemu-networking?} is true, set up networking with the standard QEMU
32233 parameters. When @var{virtio?} is true, load additional modules so that the
32234 initrd can be used as a QEMU guest with para-virtualized I/O drivers.
32236 When @var{volatile-root?} is true, the root file system is writable but any changes
32240 @deffn {Scheme Procedure} base-initrd @var{file-systems} @
32241 [#:mapped-devices '()] [#:keyboard-layout #f] @
32242 [#:qemu-networking? #f] [#:volatile-root? #f] @
32243 [#:linux-modules '()]
32244 Return as a file-like object a generic initrd, with kernel
32245 modules taken from @var{linux}. @var{file-systems} is a list of file-systems to be
32246 mounted by the initrd, possibly in addition to the root file system specified
32247 on the kernel command line via @option{--root}. @var{mapped-devices} is a list of device
32248 mappings to realize before @var{file-systems} are mounted.
32250 When true, @var{keyboard-layout} is a @code{<keyboard-layout>} record denoting
32251 the desired console keyboard layout. This is done before @var{mapped-devices}
32252 are set up and before @var{file-systems} are mounted such that, should the
32253 user need to enter a passphrase or use the REPL, this happens using the
32254 intended keyboard layout.
32256 @var{qemu-networking?} and @var{volatile-root?} behaves as in @code{raw-initrd}.
32258 The initrd is automatically populated with all the kernel modules necessary
32259 for @var{file-systems} and for the given options. Additional kernel
32260 modules can be listed in @var{linux-modules}. They will be added to the initrd, and
32261 loaded at boot time in the order in which they appear.
32264 Needless to say, the initrds we produce and use embed a
32265 statically-linked Guile, and the initialization program is a Guile
32266 program. That gives a lot of flexibility. The
32267 @code{expression->initrd} procedure builds such an initrd, given the
32268 program to run in that initrd.
32270 @deffn {Scheme Procedure} expression->initrd @var{exp} @
32271 [#:guile %guile-3.0-static-stripped] [#:name "guile-initrd"]
32272 Return as a file-like object a Linux initrd (a gzipped cpio archive)
32273 containing @var{guile} and that evaluates @var{exp}, a G-expression,
32274 upon booting. All the derivations referenced by @var{exp} are
32275 automatically copied to the initrd.
32278 @node Bootloader Configuration
32279 @section Bootloader Configuration
32282 @cindex boot loader
32284 The operating system supports multiple bootloaders. The bootloader is
32285 configured using @code{bootloader-configuration} declaration. All the
32286 fields of this structure are bootloader agnostic except for one field,
32287 @code{bootloader} that indicates the bootloader to be configured and
32290 Some of the bootloaders do not honor every field of
32291 @code{bootloader-configuration}. For instance, the extlinux
32292 bootloader does not support themes and thus ignores the @code{theme}
32295 @deftp {Data Type} bootloader-configuration
32296 The type of a bootloader configuration declaration.
32300 @item @code{bootloader}
32301 @cindex EFI, bootloader
32302 @cindex UEFI, bootloader
32303 @cindex BIOS, bootloader
32304 The bootloader to use, as a @code{bootloader} object. For now
32305 @code{grub-bootloader}, @code{grub-efi-bootloader},
32306 @code{grub-efi-netboot-bootloader}, @code{extlinux-bootloader} and
32307 @code{u-boot-bootloader} are supported.
32309 @cindex ARM, bootloaders
32310 @cindex AArch64, bootloaders
32311 Available bootloaders are described in @code{(gnu bootloader @dots{})}
32312 modules. In particular, @code{(gnu bootloader u-boot)} contains definitions
32313 of bootloaders for a wide range of ARM and AArch64 systems, using the
32314 @uref{https://www.denx.de/wiki/U-Boot/, U-Boot bootloader}.
32316 @vindex grub-efi-bootloader
32317 @code{grub-efi-bootloader} allows to boot on modern systems using the
32318 @dfn{Unified Extensible Firmware Interface} (UEFI). This is what you should
32319 use if the installation image contains a @file{/sys/firmware/efi} directory
32320 when you boot it on your system.
32322 @vindex grub-bootloader
32323 @code{grub-bootloader} allows you to boot in particular Intel-based machines
32324 in ``legacy'' BIOS mode.
32326 @vindex grub-efi-netboot-bootloader
32327 @code{grub-efi-netboot-bootloader} allows you to boot your system over network
32328 through TFTP@. In combination with an NFS root file system this allows you to
32329 build a diskless Guix system.
32331 The installation of the @code{grub-efi-netboot-bootloader} generates the content
32332 of the TFTP root directory at @code{target}
32333 (@pxref{Bootloader Configuration, @code{target}}), to be served by a TFTP server.
32334 You may want to mount your TFTP server directory onto @code{target} to move the
32335 required files to the TFTP server automatically.
32337 If you plan to use an NFS root file system as well (actually if you mount the
32338 store from an NFS share), then the TFTP server needs to serve the file
32339 @file{/boot/grub/grub.cfg} and other files from the store (like GRUBs background
32340 image, the kernel (@pxref{operating-system Reference, @code{kernel}}) and the
32341 initrd (@pxref{operating-system Reference, @code{initrd}})), too. All these
32342 files from the store will be accessed by GRUB through TFTP with their normal
32343 store path, for example as
32344 @file{tftp://tftp-server/gnu/store/…-initrd/initrd.cpio.gz}.
32346 Two symlinks are created to make this possible. The first symlink is
32347 @code{target}@file{/efi/Guix/boot/grub/grub.cfg} pointing to
32348 @file{../../../boot/grub/grub.cfg},
32349 where @code{target} may be @file{/boot}. In this case the link is not leaving
32350 the served TFTP root directory, but otherwise it does. The second link is
32351 @code{target}@file{/gnu/store} and points to @file{../gnu/store}. This link
32352 is leaving the served TFTP root directory.
32354 The assumption behind all this is that you have an NFS server exporting the root
32355 file system for your Guix system, and additionally a TFTP server exporting your
32356 @code{target} directory—usually @file{/boot}—from that same root file system for
32357 your Guix system. In this constellation the symlinks will work.
32359 For other constellations you will have to program your own bootloader installer,
32360 which then takes care to make necessary files from the store accessible through
32361 TFTP, for example by copying them into the TFTP root directory at @code{target}.
32363 It is important to note that symlinks pointing outside the TFTP root directory
32364 may need to be allowed in the configuration of your TFTP server. Further the
32365 store link exposes the whole store through TFTP@. Both points need to be
32366 considered carefully for security aspects.
32368 Beside the @code{grub-efi-netboot-bootloader}, the already mentioned TFTP and
32369 NFS servers, you also need a properly configured DHCP server to make the booting
32370 over netboot possible. For all this we can currently only recommend you to look
32371 for instructions about @acronym{PXE, Preboot eXecution Environment}.
32373 @item @code{target}
32374 This is a string denoting the target onto which to install the
32377 The interpretation depends on the bootloader in question. For
32378 @code{grub-bootloader}, for example, it should be a device name understood by
32379 the bootloader @command{installer} command, such as @code{/dev/sda} or
32380 @code{(hd0)} (@pxref{Invoking grub-install,,, grub, GNU GRUB Manual}). For
32381 @code{grub-efi-bootloader}, it should be the mount point of the EFI file
32382 system, usually @file{/boot/efi}. For @code{grub-efi-netboot-bootloader},
32383 @code{target} should be the mount point corresponding to the TFTP root
32384 directory of your TFTP server.
32386 @item @code{menu-entries} (default: @code{()})
32387 A possibly empty list of @code{menu-entry} objects (see below), denoting
32388 entries to appear in the bootloader menu, in addition to the current
32389 system entry and the entry pointing to previous system generations.
32391 @item @code{default-entry} (default: @code{0})
32392 The index of the default boot menu entry. Index 0 is for the entry of the
32395 @item @code{timeout} (default: @code{5})
32396 The number of seconds to wait for keyboard input before booting. Set to
32397 0 to boot immediately, and to -1 to wait indefinitely.
32399 @cindex keyboard layout, for the bootloader
32400 @item @code{keyboard-layout} (default: @code{#f})
32401 If this is @code{#f}, the bootloader's menu (if any) uses the default keyboard
32402 layout, usually US@tie{}English (``qwerty'').
32404 Otherwise, this must be a @code{keyboard-layout} object (@pxref{Keyboard
32408 This option is currently ignored by bootloaders other than @code{grub} and
32412 @item @code{theme} (default: @var{#f})
32413 The bootloader theme object describing the theme to use. If no theme
32414 is provided, some bootloaders might use a default theme, that's true
32417 @item @code{terminal-outputs} (default: @code{'(gfxterm)})
32418 The output terminals used for the bootloader boot menu, as a list of
32419 symbols. GRUB accepts the values: @code{console}, @code{serial},
32420 @code{serial_@{0-3@}}, @code{gfxterm}, @code{vga_text},
32421 @code{mda_text}, @code{morse}, and @code{pkmodem}. This field
32422 corresponds to the GRUB variable @code{GRUB_TERMINAL_OUTPUT} (@pxref{Simple
32423 configuration,,, grub,GNU GRUB manual}).
32425 @item @code{terminal-inputs} (default: @code{'()})
32426 The input terminals used for the bootloader boot menu, as a list of
32427 symbols. For GRUB, the default is the native platform terminal as
32428 determined at run-time. GRUB accepts the values: @code{console},
32429 @code{serial}, @code{serial_@{0-3@}}, @code{at_keyboard}, and
32430 @code{usb_keyboard}. This field corresponds to the GRUB variable
32431 @code{GRUB_TERMINAL_INPUT} (@pxref{Simple configuration,,, grub,GNU GRUB
32434 @item @code{serial-unit} (default: @code{#f})
32435 The serial unit used by the bootloader, as an integer from 0 to 3.
32436 For GRUB, it is chosen at run-time; currently GRUB chooses 0, which
32437 corresponds to COM1 (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
32439 @item @code{serial-speed} (default: @code{#f})
32440 The speed of the serial interface, as an integer. For GRUB, the
32441 default value is chosen at run-time; currently GRUB chooses
32442 9600@tie{}bps (@pxref{Serial terminal,,, grub,GNU GRUB manual}).
32449 Should you want to list additional boot menu entries @i{via} the
32450 @code{menu-entries} field above, you will need to create them with the
32451 @code{menu-entry} form. For example, imagine you want to be able to
32452 boot another distro (hard to imagine!), you can define a menu entry
32457 (label "The Other Distro")
32458 (linux "/boot/old/vmlinux-2.6.32")
32459 (linux-arguments '("root=/dev/sda2"))
32460 (initrd "/boot/old/initrd"))
32465 @deftp {Data Type} menu-entry
32466 The type of an entry in the bootloader menu.
32471 The label to show in the menu---e.g., @code{"GNU"}.
32473 @item @code{linux} (default: @code{#f})
32474 The Linux kernel image to boot, for example:
32477 (file-append linux-libre "/bzImage")
32480 For GRUB, it is also possible to specify a device explicitly in the
32481 file path using GRUB's device naming convention (@pxref{Naming
32482 convention,,, grub, GNU GRUB manual}), for example:
32485 "(hd0,msdos1)/boot/vmlinuz"
32488 If the device is specified explicitly as above, then the @code{device}
32489 field is ignored entirely.
32491 @item @code{linux-arguments} (default: @code{()})
32492 The list of extra Linux kernel command-line arguments---e.g.,
32493 @code{("console=ttyS0")}.
32495 @item @code{initrd} (default: @code{#f})
32496 A G-Expression or string denoting the file name of the initial RAM disk
32497 to use (@pxref{G-Expressions}).
32499 @item @code{device} (default: @code{#f})
32500 The device where the kernel and initrd are to be found---i.e., for GRUB,
32501 @dfn{root} for this menu entry (@pxref{root,,, grub, GNU GRUB manual}).
32503 This may be a file system label (a string), a file system UUID (a
32504 bytevector, @pxref{File Systems}), or @code{#f}, in which case
32505 the bootloader will search the device containing the file specified by
32506 the @code{linux} field (@pxref{search,,, grub, GNU GRUB manual}). It
32507 must @emph{not} be an OS device name such as @file{/dev/sda1}.
32509 @item @code{multiboot-kernel} (default: @code{#f})
32510 The kernel to boot in Multiboot-mode (@pxref{multiboot,,, grub, GNU GRUB
32511 manual}). When this field is set, a Multiboot menu-entry is generated.
32515 (file-append mach "/boot/gnumach")
32518 @item @code{multiboot-arguments} (default: @code{()})
32519 The list of extra command-line arguments for the multiboot-kernel.
32521 @item @code{multiboot-modules} (default: @code{()})
32522 The list of commands for loading Multiboot modules. For example:
32525 (list (list (file-append hurd "/hurd/ext2fs.static") "ext2fs"
32527 (list (file-append libc "/lib/ld.so.1") "exec"
32537 @c FIXME: Write documentation once it's stable.
32538 For now only GRUB has theme support. GRUB themes are created using
32539 the @code{grub-theme} form, which is not fully documented yet.
32541 @deftp {Data Type} grub-theme
32542 Data type representing the configuration of the GRUB theme.
32545 @item @code{gfxmode} (default: @code{'("auto")})
32546 The GRUB @code{gfxmode} to set (a list of screen resolution strings,
32547 @pxref{gfxmode,,, grub, GNU GRUB manual}).
32551 @deffn {Scheme Procedure} grub-theme
32552 Return the default GRUB theme used by the operating system if no
32553 @code{theme} field is specified in @code{bootloader-configuration}
32556 It comes with a fancy background image displaying the GNU and Guix
32560 For example, to override the default resolution, you may use something
32565 (bootloader-configuration
32568 (inherit (grub-theme))
32569 (gfxmode '("1024x786x32" "auto"))))))
32572 @node Invoking guix system
32573 @section Invoking @code{guix system}
32575 Once you have written an operating system declaration as seen in the
32576 previous section, it can be @dfn{instantiated} using the @command{guix
32577 system} command. The synopsis is:
32580 guix system @var{options}@dots{} @var{action} @var{file}
32583 @var{file} must be the name of a file containing an
32584 @code{operating-system} declaration. @var{action} specifies how the
32585 operating system is instantiated. Currently the following values are
32590 Display available service type definitions that match the given regular
32591 expressions, sorted by relevance:
32597 $ guix system search console
32598 name: console-fonts
32599 location: gnu/services/base.scm:806:2
32600 extends: shepherd-root
32601 description: Install the given fonts on the specified ttys (fonts are per
32602 + virtual console on GNU/Linux). The value of this service is a list of
32603 + tty/font pairs. The font can be the name of a font provided by the `kbd'
32604 + package or any valid argument to `setfont', as in this example:
32606 + '(("tty1" . "LatGrkCyr-8x16")
32607 + ("tty2" . (file-append
32609 + "/share/kbd/consolefonts/TamzenForPowerline10x20.psf"))
32610 + ("tty3" . (file-append
32612 + "/share/consolefonts/ter-132n"))) ; for HDPI
32616 location: gnu/services/base.scm:1190:2
32617 extends: shepherd-root
32618 description: Provide console login using the `mingetty' program.
32622 location: gnu/services/base.scm:860:2
32624 description: Provide a console log-in service as specified by its
32625 + configuration value, a `login-configuration' object.
32631 As for @command{guix package --search}, the result is written in
32632 @code{recutils} format, which makes it easy to filter the output
32633 (@pxref{Top, GNU recutils databases,, recutils, GNU recutils manual}).
32636 Build the operating system described in @var{file}, activate it, and
32637 switch to it@footnote{This action (and the related actions
32638 @code{switch-generation} and @code{roll-back}) are usable only on
32639 systems already running Guix System.}.
32642 @c The paragraph below refers to the problem discussed at
32643 @c <https://lists.gnu.org/archive/html/guix-devel/2014-08/msg00057.html>.
32644 It is highly recommended to run @command{guix pull} once before you run
32645 @command{guix system reconfigure} for the first time (@pxref{Invoking
32646 guix pull}). Failing to do that you would see an older version of Guix
32647 once @command{reconfigure} has completed.
32650 This effects all the configuration specified in @var{file}: user
32651 accounts, system services, global package list, setuid programs, etc.
32652 The command starts system services specified in @var{file} that are not
32653 currently running; if a service is currently running this command will
32654 arrange for it to be upgraded the next time it is stopped (e.g.@: by
32655 @code{herd stop X} or @code{herd restart X}).
32657 This command creates a new generation whose number is one greater than
32658 the current generation (as reported by @command{guix system
32659 list-generations}). If that generation already exists, it will be
32660 overwritten. This behavior mirrors that of @command{guix package}
32661 (@pxref{Invoking guix package}).
32663 It also adds a bootloader menu entry for the new OS configuration,
32664 ---unless @option{--no-bootloader} is passed. For GRUB, it moves
32665 entries for older configurations to a submenu, allowing you to choose
32666 an older system generation at boot time should you need it.
32668 @cindex provenance tracking, of the operating system
32669 Upon completion, the new system is deployed under
32670 @file{/run/current-system}. This directory contains @dfn{provenance
32671 meta-data}: the list of channels in use (@pxref{Channels}) and
32672 @var{file} itself, when available. You can view it by running:
32675 guix system describe
32678 This information is useful should you later want to inspect how this
32679 particular generation was built. In fact, assuming @var{file} is
32680 self-contained, you can later rebuild generation @var{n} of your
32681 operating system with:
32684 guix time-machine \
32685 -C /var/guix/profiles/system-@var{n}-link/channels.scm -- \
32686 system reconfigure \
32687 /var/guix/profiles/system-@var{n}-link/configuration.scm
32690 You can think of it as some sort of built-in version control! Your
32691 system is not just a binary artifact: @emph{it carries its own source}.
32692 @xref{Service Reference, @code{provenance-service-type}}, for more
32693 information on provenance tracking.
32695 By default, @command{reconfigure} @emph{prevents you from downgrading
32696 your system}, which could (re)introduce security vulnerabilities and
32697 also cause problems with ``stateful'' services such as database
32698 management systems. You can override that behavior by passing
32699 @option{--allow-downgrades}.
32701 @item switch-generation
32702 @cindex generations
32703 Switch to an existing system generation. This action atomically
32704 switches the system profile to the specified system generation. It
32705 also rearranges the system's existing bootloader menu entries. It
32706 makes the menu entry for the specified system generation the default,
32707 and it moves the entries for the other generations to a submenu, if
32708 supported by the bootloader being used. The next time the system
32709 boots, it will use the specified system generation.
32711 The bootloader itself is not being reinstalled when using this
32712 command. Thus, the installed bootloader is used with an updated
32713 configuration file.
32715 The target generation can be specified explicitly by its generation
32716 number. For example, the following invocation would switch to system
32720 guix system switch-generation 7
32723 The target generation can also be specified relative to the current
32724 generation with the form @code{+N} or @code{-N}, where @code{+3} means
32725 ``3 generations ahead of the current generation,'' and @code{-1} means
32726 ``1 generation prior to the current generation.'' When specifying a
32727 negative value such as @code{-1}, you must precede it with @code{--} to
32728 prevent it from being parsed as an option. For example:
32731 guix system switch-generation -- -1
32734 Currently, the effect of invoking this action is @emph{only} to switch
32735 the system profile to an existing generation and rearrange the
32736 bootloader menu entries. To actually start using the target system
32737 generation, you must reboot after running this action. In the future,
32738 it will be updated to do the same things as @command{reconfigure},
32739 like activating and deactivating services.
32741 This action will fail if the specified generation does not exist.
32744 @cindex rolling back
32745 Switch to the preceding system generation. The next time the system
32746 boots, it will use the preceding system generation. This is the inverse
32747 of @command{reconfigure}, and it is exactly the same as invoking
32748 @command{switch-generation} with an argument of @code{-1}.
32750 Currently, as with @command{switch-generation}, you must reboot after
32751 running this action to actually start using the preceding system
32754 @item delete-generations
32755 @cindex deleting system generations
32756 @cindex saving space
32757 Delete system generations, making them candidates for garbage collection
32758 (@pxref{Invoking guix gc}, for information on how to run the ``garbage
32761 This works in the same way as @samp{guix package --delete-generations}
32762 (@pxref{Invoking guix package, @option{--delete-generations}}). With no
32763 arguments, all system generations but the current one are deleted:
32766 guix system delete-generations
32769 You can also select the generations you want to delete. The example below
32770 deletes all the system generations that are more than two month old:
32773 guix system delete-generations 2m
32776 Running this command automatically reinstalls the bootloader with an updated
32777 list of menu entries---e.g., the ``old generations'' sub-menu in GRUB no
32778 longer lists the generations that have been deleted.
32781 Build the derivation of the operating system, which includes all the
32782 configuration files and programs needed to boot and run the system.
32783 This action does not actually install anything.
32786 Populate the given directory with all the files necessary to run the
32787 operating system specified in @var{file}. This is useful for first-time
32788 installations of Guix System. For instance:
32791 guix system init my-os-config.scm /mnt
32794 copies to @file{/mnt} all the store items required by the configuration
32795 specified in @file{my-os-config.scm}. This includes configuration
32796 files, packages, and so on. It also creates other essential files
32797 needed for the system to operate correctly---e.g., the @file{/etc},
32798 @file{/var}, and @file{/run} directories, and the @file{/bin/sh} file.
32800 This command also installs bootloader on the target specified in
32801 @file{my-os-config}, unless the @option{--no-bootloader} option was
32805 @cindex virtual machine
32807 @anchor{guix system vm}
32808 Build a virtual machine that contains the operating system declared in
32809 @var{file}, and return a script to run that virtual machine (VM).
32812 The @code{vm} action and others below
32813 can use KVM support in the Linux-libre kernel. Specifically, if the
32814 machine has hardware virtualization support, the corresponding
32815 KVM kernel module should be loaded, and the @file{/dev/kvm} device node
32816 must exist and be readable and writable by the user and by the
32817 build users of the daemon (@pxref{Build Environment Setup}).
32820 Arguments given to the script are passed to QEMU as in the example
32821 below, which enables networking and requests 1@tie{}GiB of RAM for the
32825 $ /gnu/store/@dots{}-run-vm.sh -m 1024 -smp 2 -net user,model=virtio-net-pci
32828 The VM shares its store with the host system.
32830 Additional file systems can be shared between the host and the VM using
32831 the @option{--share} and @option{--expose} command-line options: the former
32832 specifies a directory to be shared with write access, while the latter
32833 provides read-only access to the shared directory.
32835 The example below creates a VM in which the user's home directory is
32836 accessible read-only, and where the @file{/exchange} directory is a
32837 read-write mapping of @file{$HOME/tmp} on the host:
32840 guix system vm my-config.scm \
32841 --expose=$HOME --share=$HOME/tmp=/exchange
32844 On GNU/Linux, the default is to boot directly to the kernel; this has
32845 the advantage of requiring only a very tiny root disk image since the
32846 store of the host can then be mounted.
32848 The @option{--full-boot} option forces a complete boot sequence, starting
32849 with the bootloader. This requires more disk space since a root image
32850 containing at least the kernel, initrd, and bootloader data files must
32851 be created. The @option{--image-size} option can be used to specify the
32854 @cindex System images, creation in various formats
32855 @cindex Creating system images in various formats
32857 @itemx docker-image
32858 Return a virtual machine, disk image, or Docker image of the operating
32859 system declared in @var{file} that stands alone. By default,
32860 @command{guix system} estimates the size of the image needed to store
32861 the system, but you can use the @option{--image-size} option to specify
32862 a value. Docker images are built to contain exactly what they need, so
32863 the @option{--image-size} option is ignored in the case of
32864 @code{docker-image}.
32866 @cindex image, creating disk images
32867 The @code{image} command can produce various image types. The
32868 image type can be selected using the @option{--image-type} option. It
32869 defaults to @code{efi-raw}. When its value is @code{iso9660}, the
32870 @option{--label} option can be used to specify a volume ID with
32871 @code{image}. By default, the root file system of a disk image is
32872 mounted non-volatile; the @option{--volatile} option can be provided to
32873 make it volatile instead. When using @code{image}, the bootloader
32874 installed on the generated image is taken from the provided
32875 @code{operating-system} definition. The following example demonstrates
32876 how to generate an image that uses the @code{grub-efi-bootloader}
32877 bootloader and boot it with QEMU:
32880 image=$(guix system image --image-type=qcow2 \
32881 gnu/system/examples/lightweight-desktop.tmpl)
32882 cp $image /tmp/my-image.qcow2
32883 chmod +w /tmp/my-image.qcow2
32884 qemu-system-x86_64 -enable-kvm -hda /tmp/my-image.qcow2 -m 1000 \
32885 -bios $(guix build ovmf)/share/firmware/ovmf_x64.bin
32888 When using the @code{efi-raw} image type, a raw disk image is produced;
32889 it can be copied as is to a USB stick, for instance. Assuming
32890 @code{/dev/sdc} is the device corresponding to a USB stick, one can copy
32891 the image to it using the following command:
32894 # dd if=$(guix system image my-os.scm) of=/dev/sdc status=progress
32897 The @code{--list-image-types} command lists all the available image
32900 @cindex creating virtual machine images
32901 When using the @code{qcow2} image type, the returned image is in qcow2
32902 format, which the QEMU emulator can efficiently use. @xref{Running Guix
32903 in a VM}, for more information on how to run the image in a virtual
32904 machine. The @code{grub-bootloader} bootloader is always used
32905 independently of what is declared in the @code{operating-system} file
32906 passed as argument. This is to make it easier to work with QEMU, which
32907 uses the SeaBIOS BIOS by default, expecting a bootloader to be installed
32908 in the Master Boot Record (MBR).
32910 @cindex docker-image, creating docker images
32911 When using @code{docker-image}, a Docker image is produced. Guix builds
32912 the image from scratch, not from a pre-existing Docker base image. As a
32913 result, it contains @emph{exactly} what you define in the operating
32914 system configuration file. You can then load the image and launch a
32915 Docker container using commands like the following:
32918 image_id="`docker load < guix-system-docker-image.tar.gz`"
32919 container_id="`docker create $image_id`"
32920 docker start $container_id
32923 This command starts a new Docker container from the specified image. It
32924 will boot the Guix system in the usual manner, which means it will
32925 start any services you have defined in the operating system
32926 configuration. You can get an interactive shell running in the container
32927 using @command{docker exec}:
32930 docker exec -ti $container_id /run/current-system/profile/bin/bash --login
32933 Depending on what you run in the Docker container, it
32934 may be necessary to give the container additional permissions. For
32935 example, if you intend to build software using Guix inside of the Docker
32936 container, you may need to pass the @option{--privileged} option to
32937 @code{docker create}.
32939 Last, the @option{--network} option applies to @command{guix system
32940 docker-image}: it produces an image where network is supposedly shared
32941 with the host, and thus without services like nscd or NetworkManager.
32944 Return a script to run the operating system declared in @var{file}
32945 within a container. Containers are a set of lightweight isolation
32946 mechanisms provided by the kernel Linux-libre. Containers are
32947 substantially less resource-demanding than full virtual machines since
32948 the kernel, shared objects, and other resources can be shared with the
32949 host system; this also means they provide thinner isolation.
32951 Currently, the script must be run as root in order to support more than
32952 a single user and group. The container shares its store with the host
32955 As with the @code{vm} action (@pxref{guix system vm}), additional file
32956 systems to be shared between the host and container can be specified
32957 using the @option{--share} and @option{--expose} options:
32960 guix system container my-config.scm \
32961 --expose=$HOME --share=$HOME/tmp=/exchange
32965 This option requires Linux-libre 3.19 or newer.
32970 @var{options} can contain any of the common build options (@pxref{Common
32971 Build Options}). In addition, @var{options} can contain one of the
32975 @item --expression=@var{expr}
32976 @itemx -e @var{expr}
32977 Consider the operating-system @var{expr} evaluates to.
32978 This is an alternative to specifying a file which evaluates to an
32980 This is used to generate the Guix system installer @pxref{Building the
32981 Installation Image}).
32983 @item --system=@var{system}
32984 @itemx -s @var{system}
32985 Attempt to build for @var{system} instead of the host system type.
32986 This works as per @command{guix build} (@pxref{Invoking guix build}).
32990 Return the derivation file name of the given operating system without
32993 @cindex provenance tracking, of the operating system
32994 @item --save-provenance
32995 As discussed above, @command{guix system init} and @command{guix system
32996 reconfigure} always save provenance information @i{via} a dedicated
32997 service (@pxref{Service Reference, @code{provenance-service-type}}).
32998 However, other commands don't do that by default. If you wish to, say,
32999 create a virtual machine image that contains provenance information, you
33003 guix system image -t qcow2 --save-provenance config.scm
33006 That way, the resulting image will effectively ``embed its own source''
33007 in the form of meta-data in @file{/run/current-system}. With that
33008 information, one can rebuild the image to make sure it really contains
33009 what it pretends to contain; or they could use that to derive a variant
33012 @item --image-type=@var{type}
33013 @itemx -t @var{type}
33014 For the @code{image} action, create an image with given @var{type}.
33016 When this option is omitted, @command{guix system} uses the
33017 @code{efi-raw} image type.
33019 @cindex ISO-9660 format
33020 @cindex CD image format
33021 @cindex DVD image format
33022 @option{--image-type=iso9660} produces an ISO-9660 image, suitable
33023 for burning on CDs and DVDs.
33025 @item --image-size=@var{size}
33026 For the @code{image} action, create an image of the given @var{size}.
33027 @var{size} may be a number of bytes, or it may include a unit as a
33028 suffix (@pxref{Block size, size specifications,, coreutils, GNU
33031 When this option is omitted, @command{guix system} computes an estimate
33032 of the image size as a function of the size of the system declared in
33037 For the @code{container} action, allow containers to access the host network,
33038 that is, do not create a network namespace.
33040 @item --root=@var{file}
33041 @itemx -r @var{file}
33042 Make @var{file} a symlink to the result, and register it as a garbage
33045 @item --skip-checks
33046 Skip pre-installation safety checks.
33048 By default, @command{guix system init} and @command{guix system
33049 reconfigure} perform safety checks: they make sure the file systems that
33050 appear in the @code{operating-system} declaration actually exist
33051 (@pxref{File Systems}), and that any Linux kernel modules that may be
33052 needed at boot time are listed in @code{initrd-modules} (@pxref{Initial
33053 RAM Disk}). Passing this option skips these tests altogether.
33055 @item --allow-downgrades
33056 Instruct @command{guix system reconfigure} to allow system downgrades.
33058 By default, @command{reconfigure} prevents you from downgrading your
33059 system. It achieves that by comparing the provenance info of your
33060 system (shown by @command{guix system describe}) with that of your
33061 @command{guix} command (shown by @command{guix describe}). If the
33062 commits for @command{guix} are not descendants of those used for your
33063 system, @command{guix system reconfigure} errors out. Passing
33064 @option{--allow-downgrades} allows you to bypass these checks.
33067 Make sure you understand its security implications before using
33068 @option{--allow-downgrades}.
33072 @cindex on-error strategy
33073 @cindex error strategy
33074 @item --on-error=@var{strategy}
33075 Apply @var{strategy} when an error occurs when reading @var{file}.
33076 @var{strategy} may be one of the following:
33079 @item nothing-special
33080 Report the error concisely and exit. This is the default strategy.
33083 Likewise, but also display a backtrace.
33086 Report the error and enter Guile's debugger. From there, you can run
33087 commands such as @code{,bt} to get a backtrace, @code{,locals} to
33088 display local variable values, and more generally inspect the state of the
33089 program. @xref{Debug Commands,,, guile, GNU Guile Reference Manual}, for
33090 a list of available debugging commands.
33094 Once you have built, configured, re-configured, and re-re-configured
33095 your Guix installation, you may find it useful to list the operating
33096 system generations available on disk---and that you can choose from the
33097 bootloader boot menu:
33102 Describe the current system generation: its file name, the kernel and
33103 bootloader used, etc., as well as provenance information when available.
33105 @item list-generations
33106 List a summary of each generation of the operating system available on
33107 disk, in a human-readable way. This is similar to the
33108 @option{--list-generations} option of @command{guix package}
33109 (@pxref{Invoking guix package}).
33111 Optionally, one can specify a pattern, with the same syntax that is used
33112 in @command{guix package --list-generations}, to restrict the list of
33113 generations displayed. For instance, the following command displays
33114 generations that are up to 10 days old:
33117 $ guix system list-generations 10d
33122 The @command{guix system} command has even more to offer! The following
33123 sub-commands allow you to visualize how your system services relate to
33126 @anchor{system-extension-graph}
33129 @item extension-graph
33130 Emit to standard output the @dfn{service
33131 extension graph} of the operating system defined in @var{file}
33132 (@pxref{Service Composition}, for more information on service
33133 extensions). By default the output is in Dot/Graphviz format, but you
33134 can choose a different format with @option{--graph-backend}, as with
33135 @command{guix graph} (@pxref{Invoking guix graph, @option{--backend}}):
33140 $ guix system extension-graph @var{file} | xdot -
33143 shows the extension relations among services.
33145 @anchor{system-shepherd-graph}
33146 @item shepherd-graph
33147 Emit to standard output the @dfn{dependency
33148 graph} of shepherd services of the operating system defined in
33149 @var{file}. @xref{Shepherd Services}, for more information and for an
33152 Again, the default output format is Dot/Graphviz, but you can pass
33153 @option{--graph-backend} to select a different one.
33157 @node Invoking guix deploy
33158 @section Invoking @code{guix deploy}
33160 We've already seen @code{operating-system} declarations used to manage a
33161 machine's configuration locally. Suppose you need to configure multiple
33162 machines, though---perhaps you're managing a service on the web that's
33163 comprised of several servers. @command{guix deploy} enables you to use those
33164 same @code{operating-system} declarations to manage multiple remote hosts at
33165 once as a logical ``deployment''.
33168 The functionality described in this section is still under development
33169 and is subject to change. Get in touch with us on
33170 @email{guix-devel@@gnu.org}!
33174 guix deploy @var{file}
33177 Such an invocation will deploy the machines that the code within @var{file}
33178 evaluates to. As an example, @var{file} might contain a definition like this:
33181 ;; This is a Guix deployment of a "bare bones" setup, with
33182 ;; no X11 display server, to a machine with an SSH daemon
33183 ;; listening on localhost:2222. A configuration such as this
33184 ;; may be appropriate for virtual machine with ports
33185 ;; forwarded to the host's loopback interface.
33187 (use-service-modules networking ssh)
33188 (use-package-modules bootloaders)
33192 (host-name "gnu-deployed")
33193 (timezone "Etc/UTC")
33194 (bootloader (bootloader-configuration
33195 (bootloader grub-bootloader)
33196 (target "/dev/vda")
33197 (terminal-outputs '(console))))
33198 (file-systems (cons (file-system
33200 (device "/dev/vda1")
33202 %base-file-systems))
33204 (append (list (service dhcp-client-service-type)
33205 (service openssh-service-type
33206 (openssh-configuration
33207 (permit-root-login #t)
33208 (allow-empty-passwords? #t))))
33212 (operating-system %system)
33213 (environment managed-host-environment-type)
33214 (configuration (machine-ssh-configuration
33215 (host-name "localhost")
33216 (system "x86_64-linux")
33218 (identity "./id_rsa")
33222 The file should evaluate to a list of @var{machine} objects. This example,
33223 upon being deployed, will create a new generation on the remote system
33224 realizing the @code{operating-system} declaration @code{%system}.
33225 @code{environment} and @code{configuration} specify how the machine should be
33226 provisioned---that is, how the computing resources should be created and
33227 managed. The above example does not create any resources, as a
33228 @code{'managed-host} is a machine that is already running the Guix system and
33229 available over the network. This is a particularly simple case; a more
33230 complex deployment may involve, for example, starting virtual machines through
33231 a Virtual Private Server (VPS) provider. In such a case, a different
33232 @var{environment} type would be used.
33234 Do note that you first need to generate a key pair on the coordinator machine
33235 to allow the daemon to export signed archives of files from the store
33236 (@pxref{Invoking guix archive}), though this step is automatic on Guix
33240 # guix archive --generate-key
33244 Each target machine must authorize the key of the master machine so that it
33245 accepts store items it receives from the coordinator:
33248 # guix archive --authorize < coordinator-public-key.txt
33251 @code{user}, in this example, specifies the name of the user account to log in
33252 as to perform the deployment. Its default value is @code{root}, but root
33253 login over SSH may be forbidden in some cases. To work around this,
33254 @command{guix deploy} can log in as an unprivileged user and employ
33255 @code{sudo} to escalate privileges. This will only work if @code{sudo} is
33256 currently installed on the remote and can be invoked non-interactively as
33257 @code{user}. That is, the line in @code{sudoers} granting @code{user} the
33258 ability to use @code{sudo} must contain the @code{NOPASSWD} tag. This can
33259 be accomplished with the following operating system configuration snippet:
33263 (gnu system)) ;for %sudoers-specification
33265 (define %user "username")
33270 (plain-file "sudoers"
33271 (string-append (plain-file-content %sudoers-specification)
33272 (format #f "~a ALL = NOPASSWD: ALL~%"
33277 For more information regarding the format of the @file{sudoers} file,
33278 consult @command{man sudoers}.
33280 @deftp {Data Type} machine
33281 This is the data type representing a single machine in a heterogeneous Guix
33285 @item @code{operating-system}
33286 The object of the operating system configuration to deploy.
33288 @item @code{environment}
33289 An @code{environment-type} describing how the machine should be provisioned.
33291 @item @code{configuration} (default: @code{#f})
33292 An object describing the configuration for the machine's @code{environment}.
33293 If the @code{environment} has a default configuration, @code{#f} may be used.
33294 If @code{#f} is used for an environment with no default configuration,
33295 however, an error will be thrown.
33299 @deftp {Data Type} machine-ssh-configuration
33300 This is the data type representing the SSH client parameters for a machine
33301 with an @code{environment} of @code{managed-host-environment-type}.
33304 @item @code{host-name}
33305 @item @code{build-locally?} (default: @code{#t})
33306 If false, system derivations will be built on the machine being deployed to.
33307 @item @code{system}
33308 The system type describing the architecture of the machine being deployed
33309 to---e.g., @code{"x86_64-linux"}.
33310 @item @code{authorize?} (default: @code{#t})
33311 If true, the coordinator's signing key will be added to the remote's ACL
33313 @item @code{port} (default: @code{22})
33314 @item @code{user} (default: @code{"root"})
33315 @item @code{identity} (default: @code{#f})
33316 If specified, the path to the SSH private key to use to authenticate with the
33319 @item @code{host-key} (default: @code{#f})
33320 This should be the SSH host key of the machine, which looks like this:
33323 ssh-ed25519 AAAAC3Nz@dots{} root@@example.org
33326 When @code{host-key} is @code{#f}, the server is authenticated against
33327 the @file{~/.ssh/known_hosts} file, just like the OpenSSH @command{ssh}
33330 @item @code{allow-downgrades?} (default: @code{#f})
33331 Whether to allow potential downgrades.
33333 Like @command{guix system reconfigure}, @command{guix deploy} compares
33334 the channel commits currently deployed on the remote host (as returned
33335 by @command{guix system describe}) to those currently in use (as
33336 returned by @command{guix describe}) to determine whether commits
33337 currently in use are descendants of those deployed. When this is not
33338 the case and @code{allow-downgrades?} is false, it raises an error.
33339 This ensures you do not accidentally downgrade remote machines.
33343 @deftp {Data Type} digital-ocean-configuration
33344 This is the data type describing the Droplet that should be created for a
33345 machine with an @code{environment} of @code{digital-ocean-environment-type}.
33348 @item @code{ssh-key}
33349 The path to the SSH private key to use to authenticate with the remote
33350 host. In the future, this field may not exist.
33352 A list of string ``tags'' that uniquely identify the machine. Must be given
33353 such that no two machines in the deployment have the same set of tags.
33354 @item @code{region}
33355 A Digital Ocean region slug, such as @code{"nyc3"}.
33357 A Digital Ocean size slug, such as @code{"s-1vcpu-1gb"}
33358 @item @code{enable-ipv6?}
33359 Whether or not the droplet should be created with IPv6 networking.
33363 @node Running Guix in a VM
33364 @section Running Guix in a Virtual Machine
33366 @cindex virtual machine
33367 To run Guix in a virtual machine (VM), one can use the pre-built Guix VM image
33369 @url{@value{BASE-URL}/guix-system-vm-image-@value{VERSION}.x86_64-linux.xz}.
33370 This image is a compressed image in QCOW format. You will first need to
33371 decompress with @command{xz -d}, and then you can pass it to an emulator such
33372 as QEMU (see below for details).
33374 This image boots the Xfce graphical environment and it contains some
33375 commonly used tools. You can install more software in the image by running
33376 @command{guix package} in a terminal (@pxref{Invoking guix package}). You can
33377 also reconfigure the system based on its initial configuration file available
33378 as @file{/run/current-system/configuration.scm} (@pxref{Using the
33379 Configuration System}).
33381 Instead of using this pre-built image, one can also build their own virtual
33382 machine image using @command{guix system vm-image} (@pxref{Invoking guix
33383 system}). The returned image is in qcow2 format, which the
33384 @uref{https://qemu.org/, QEMU emulator} can efficiently use.
33387 If you built your own image, you must copy it out of the store
33388 (@pxref{The Store}) and give yourself permission to write to the copy
33389 before you can use it. When invoking QEMU, you must choose a system
33390 emulator that is suitable for your hardware platform. Here is a minimal
33391 QEMU invocation that will boot the result of @command{guix system
33392 image -t qcow2} on x86_64 hardware:
33395 $ qemu-system-x86_64 \
33396 -nic user,model=virtio-net-pci \
33397 -enable-kvm -m 1024 \
33398 -device virtio-blk,drive=myhd \
33399 -drive if=none,file=/tmp/qemu-image,id=myhd
33402 Here is what each of these options means:
33405 @item qemu-system-x86_64
33406 This specifies the hardware platform to emulate. This should match the
33409 @item -nic user,model=virtio-net-pci
33410 Enable the unprivileged user-mode network stack. The guest OS can
33411 access the host but not vice versa. This is the simplest way to get the
33412 guest OS online. @code{model} specifies which network device to emulate:
33413 @code{virtio-net-pci} is a special device made for virtualized operating
33414 systems and recommended for most uses. Assuming your hardware platform is
33415 x86_64, you can get a list of available NIC models by running
33416 @command{qemu-system-x86_64 -nic model=help}.
33419 If your system has hardware virtualization extensions, enabling the
33420 virtual machine support (KVM) of the Linux kernel will make things run
33423 @c To run Xfce + 'guix pull', we need at least 1G of RAM.
33425 RAM available to the guest OS, in mebibytes. Defaults to 128@tie{}MiB,
33426 which may be insufficient for some operations.
33428 @item -device virtio-blk,drive=myhd
33429 Create a @code{virtio-blk} drive called ``myhd''. @code{virtio-blk} is a
33430 ``paravirtualization'' mechanism for block devices that allows QEMU to achieve
33431 better performance than if it were emulating a complete disk drive. See the
33432 QEMU and KVM documentation for more info.
33434 @item -drive if=none,file=/tmp/qemu-image,id=myhd
33435 Use our QCOW image, the @file{/tmp/qemu-image} file, as the backing
33436 store of the ``myhd'' drive.
33439 The default @command{run-vm.sh} script that is returned by an invocation of
33440 @command{guix system vm} does not add a @command{-nic user} flag by default.
33441 To get network access from within the vm add the @code{(dhcp-client-service)}
33442 to your system definition and start the VM using
33443 @command{`guix system vm config.scm` -nic user}. An important caveat of using
33444 @command{-nic user} for networking is that @command{ping} will not work, because
33445 it uses the ICMP protocol. You'll have to use a different command to check for
33446 network connectivity, for example @command{guix download}.
33448 @subsection Connecting Through SSH
33452 To enable SSH inside a VM you need to add an SSH server like
33453 @code{openssh-service-type} to your VM (@pxref{Networking Services,
33454 @code{openssh-service-type}}). In addition you need to forward the SSH port,
33455 22 by default, to the host. You can do this with
33458 `guix system vm config.scm` -nic user,model=virtio-net-pci,hostfwd=tcp::10022-:22
33461 To connect to the VM you can run
33464 ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -p 10022
33467 The @command{-p} tells @command{ssh} the port you want to connect to.
33468 @command{-o UserKnownHostsFile=/dev/null} prevents @command{ssh} from complaining
33469 every time you modify your @command{config.scm} file and the
33470 @command{-o StrictHostKeyChecking=no} prevents you from having to allow a
33471 connection to an unknown host every time you connect.
33473 @subsection Using @command{virt-viewer} with Spice
33475 As an alternative to the default @command{qemu} graphical client you can
33476 use the @command{remote-viewer} from the @command{virt-viewer} package. To
33477 connect pass the @command{-spice port=5930,disable-ticketing} flag to
33478 @command{qemu}. See previous section for further information on how to do this.
33480 Spice also allows you to do some nice stuff like share your clipboard with your
33481 VM@. To enable that you'll also have to pass the following flags to @command{qemu}:
33484 -device virtio-serial-pci,id=virtio-serial0,max_ports=16,bus=pci.0,addr=0x5
33485 -chardev spicevmc,name=vdagent,id=vdagent
33486 -device virtserialport,nr=1,bus=virtio-serial0.0,chardev=vdagent,
33487 name=com.redhat.spice.0
33490 You'll also need to add the @code{(spice-vdagent-service)} to your
33491 system definition (@pxref{Miscellaneous Services, Spice service}).
33493 @node Defining Services
33494 @section Defining Services
33496 The previous sections show the available services and how one can combine
33497 them in an @code{operating-system} declaration. But how do we define
33498 them in the first place? And what is a service anyway?
33501 * Service Composition:: The model for composing services.
33502 * Service Types and Services:: Types and services.
33503 * Service Reference:: API reference.
33504 * Shepherd Services:: A particular type of service.
33507 @node Service Composition
33508 @subsection Service Composition
33512 Here we define a @dfn{service} as, broadly, something that extends the
33513 functionality of the operating system. Often a service is a process---a
33514 @dfn{daemon}---started when the system boots: a secure shell server, a
33515 Web server, the Guix build daemon, etc. Sometimes a service is a daemon
33516 whose execution can be triggered by another daemon---e.g., an FTP server
33517 started by @command{inetd} or a D-Bus service activated by
33518 @command{dbus-daemon}. Occasionally, a service does not map to a
33519 daemon. For instance, the ``account'' service collects user accounts
33520 and makes sure they exist when the system runs; the ``udev'' service
33521 collects device management rules and makes them available to the eudev
33522 daemon; the @file{/etc} service populates the @file{/etc} directory
33525 @cindex service extensions
33526 Guix system services are connected by @dfn{extensions}. For instance, the
33527 secure shell service @emph{extends} the Shepherd---the
33528 initialization system, running as PID@tie{}1---by giving it the command
33529 lines to start and stop the secure shell daemon (@pxref{Networking
33530 Services, @code{openssh-service-type}}); the UPower service extends the D-Bus
33531 service by passing it its @file{.service} specification, and extends the
33532 udev service by passing it device management rules (@pxref{Desktop
33533 Services, @code{upower-service}}); the Guix daemon service extends the
33534 Shepherd by passing it the command lines to start and stop the daemon,
33535 and extends the account service by passing it a list of required build
33536 user accounts (@pxref{Base Services}).
33538 All in all, services and their ``extends'' relations form a directed
33539 acyclic graph (DAG). If we represent services as boxes and extensions
33540 as arrows, a typical system might provide something like this:
33542 @image{images/service-graph,,5in,Typical service extension graph.}
33544 @cindex system service
33545 At the bottom, we see the @dfn{system service}, which produces the
33546 directory containing everything to run and boot the system, as returned
33547 by the @command{guix system build} command. @xref{Service Reference},
33548 to learn about the other service types shown here.
33549 @xref{system-extension-graph, the @command{guix system extension-graph}
33550 command}, for information on how to generate this representation for a
33551 particular operating system definition.
33553 @cindex service types
33554 Technically, developers can define @dfn{service types} to express these
33555 relations. There can be any number of services of a given type on the
33556 system---for instance, a system running two instances of the GNU secure
33557 shell server (lsh) has two instances of @code{lsh-service-type}, with
33558 different parameters.
33560 The following section describes the programming interface for service
33561 types and services.
33563 @node Service Types and Services
33564 @subsection Service Types and Services
33566 A @dfn{service type} is a node in the DAG described above. Let us start
33567 with a simple example, the service type for the Guix build daemon
33568 (@pxref{Invoking guix-daemon}):
33571 (define guix-service-type
33575 (list (service-extension shepherd-root-service-type guix-shepherd-service)
33576 (service-extension account-service-type guix-accounts)
33577 (service-extension activation-service-type guix-activation)))
33578 (default-value (guix-configuration))))
33582 It defines three things:
33586 A name, whose sole purpose is to make inspection and debugging easier.
33589 A list of @dfn{service extensions}, where each extension designates the
33590 target service type and a procedure that, given the parameters of the
33591 service, returns a list of objects to extend the service of that type.
33593 Every service type has at least one service extension. The only
33594 exception is the @dfn{boot service type}, which is the ultimate service.
33597 Optionally, a default value for instances of this type.
33600 In this example, @code{guix-service-type} extends three services:
33603 @item shepherd-root-service-type
33604 The @code{guix-shepherd-service} procedure defines how the Shepherd
33605 service is extended. Namely, it returns a @code{<shepherd-service>}
33606 object that defines how @command{guix-daemon} is started and stopped
33607 (@pxref{Shepherd Services}).
33609 @item account-service-type
33610 This extension for this service is computed by @code{guix-accounts},
33611 which returns a list of @code{user-group} and @code{user-account}
33612 objects representing the build user accounts (@pxref{Invoking
33615 @item activation-service-type
33616 Here @code{guix-activation} is a procedure that returns a gexp, which is
33617 a code snippet to run at ``activation time''---e.g., when the service is
33621 A service of this type is instantiated like this:
33624 (service guix-service-type
33625 (guix-configuration
33627 (extra-options '("--gc-keep-derivations"))))
33630 The second argument to the @code{service} form is a value representing
33631 the parameters of this specific service instance.
33632 @xref{guix-configuration-type, @code{guix-configuration}}, for
33633 information about the @code{guix-configuration} data type. When the
33634 value is omitted, the default value specified by
33635 @code{guix-service-type} is used:
33638 (service guix-service-type)
33641 @code{guix-service-type} is quite simple because it extends other
33642 services but is not extensible itself.
33644 @c @subsubsubsection Extensible Service Types
33646 The service type for an @emph{extensible} service looks like this:
33649 (define udev-service-type
33650 (service-type (name 'udev)
33652 (list (service-extension shepherd-root-service-type
33653 udev-shepherd-service)))
33655 (compose concatenate) ;concatenate the list of rules
33656 (extend (lambda (config rules)
33658 (($ <udev-configuration> udev initial-rules)
33659 (udev-configuration
33660 (udev udev) ;the udev package to use
33661 (rules (append initial-rules rules)))))))))
33664 This is the service type for the
33665 @uref{https://wiki.gentoo.org/wiki/Project:Eudev, eudev device
33666 management daemon}. Compared to the previous example, in addition to an
33667 extension of @code{shepherd-root-service-type}, we see two new fields:
33671 This is the procedure to @dfn{compose} the list of extensions to
33672 services of this type.
33674 Services can extend the udev service by passing it lists of rules; we
33675 compose those extensions simply by concatenating them.
33678 This procedure defines how the value of the service is @dfn{extended} with
33679 the composition of the extensions.
33681 Udev extensions are composed into a list of rules, but the udev service
33682 value is itself a @code{<udev-configuration>} record. So here, we
33683 extend that record by appending the list of rules it contains to the
33684 list of contributed rules.
33687 This is a string giving an overview of the service type. The string can
33688 contain Texinfo markup (@pxref{Overview,,, texinfo, GNU Texinfo}). The
33689 @command{guix system search} command searches these strings and displays
33690 them (@pxref{Invoking guix system}).
33693 There can be only one instance of an extensible service type such as
33694 @code{udev-service-type}. If there were more, the
33695 @code{service-extension} specifications would be ambiguous.
33697 Still here? The next section provides a reference of the programming
33698 interface for services.
33700 @node Service Reference
33701 @subsection Service Reference
33703 We have seen an overview of service types (@pxref{Service Types and
33704 Services}). This section provides a reference on how to manipulate
33705 services and service types. This interface is provided by the
33706 @code{(gnu services)} module.
33708 @deffn {Scheme Procedure} service @var{type} [@var{value}]
33709 Return a new service of @var{type}, a @code{<service-type>} object (see
33710 below). @var{value} can be any object; it represents the parameters of
33711 this particular service instance.
33713 When @var{value} is omitted, the default value specified by @var{type}
33714 is used; if @var{type} does not specify a default value, an error is
33717 For instance, this:
33720 (service openssh-service-type)
33724 is equivalent to this:
33727 (service openssh-service-type
33728 (openssh-configuration))
33731 In both cases the result is an instance of @code{openssh-service-type}
33732 with the default configuration.
33735 @deffn {Scheme Procedure} service? @var{obj}
33736 Return true if @var{obj} is a service.
33739 @deffn {Scheme Procedure} service-kind @var{service}
33740 Return the type of @var{service}---i.e., a @code{<service-type>} object.
33743 @deffn {Scheme Procedure} service-value @var{service}
33744 Return the value associated with @var{service}. It represents its
33748 Here is an example of how a service is created and manipulated:
33752 (service nginx-service-type
33753 (nginx-configuration
33755 (log-directory log-directory)
33756 (run-directory run-directory)
33757 (file config-file))))
33762 (eq? (service-kind s) nginx-service-type)
33766 The @code{modify-services} form provides a handy way to change the
33767 parameters of some of the services of a list such as
33768 @code{%base-services} (@pxref{Base Services, @code{%base-services}}). It
33769 evaluates to a list of services. Of course, you could always use
33770 standard list combinators such as @code{map} and @code{fold} to do that
33771 (@pxref{SRFI-1, List Library,, guile, GNU Guile Reference Manual});
33772 @code{modify-services} simply provides a more concise form for this
33775 @deffn {Scheme Syntax} modify-services @var{services} @
33776 (@var{type} @var{variable} => @var{body}) @dots{}
33778 Modify the services listed in @var{services} according to the given
33779 clauses. Each clause has the form:
33782 (@var{type} @var{variable} => @var{body})
33785 where @var{type} is a service type---e.g.,
33786 @code{guix-service-type}---and @var{variable} is an identifier that is
33787 bound within the @var{body} to the service parameters---e.g., a
33788 @code{guix-configuration} instance---of the original service of that
33791 The @var{body} should evaluate to the new service parameters, which will
33792 be used to configure the new service. This new service will replace the
33793 original in the resulting list. Because a service's service parameters
33794 are created using @code{define-record-type*}, you can write a succinct
33795 @var{body} that evaluates to the new service parameters by using the
33796 @code{inherit} feature that @code{define-record-type*} provides.
33798 @xref{Using the Configuration System}, for example usage.
33802 Next comes the programming interface for service types. This is
33803 something you want to know when writing new service definitions, but not
33804 necessarily when simply looking for ways to customize your
33805 @code{operating-system} declaration.
33807 @deftp {Data Type} service-type
33808 @cindex service type
33809 This is the representation of a @dfn{service type} (@pxref{Service Types
33814 This is a symbol, used only to simplify inspection and debugging.
33816 @item @code{extensions}
33817 A non-empty list of @code{<service-extension>} objects (see below).
33819 @item @code{compose} (default: @code{#f})
33820 If this is @code{#f}, then the service type denotes services that cannot
33821 be extended---i.e., services that do not receive ``values'' from other
33824 Otherwise, it must be a one-argument procedure. The procedure is called
33825 by @code{fold-services} and is passed a list of values collected from
33826 extensions. It may return any single value.
33828 @item @code{extend} (default: @code{#f})
33829 If this is @code{#f}, services of this type cannot be extended.
33831 Otherwise, it must be a two-argument procedure: @code{fold-services}
33832 calls it, passing it the initial value of the service as the first
33833 argument and the result of applying @code{compose} to the extension
33834 values as the second argument. It must return a value that is a valid
33835 parameter value for the service instance.
33837 @item @code{description}
33838 This is a string, possibly using Texinfo markup, describing in a couple
33839 of sentences what the service is about. This string allows users to
33840 find about the service through @command{guix system search}
33841 (@pxref{Invoking guix system}).
33843 @item @code{default-value} (default: @code{&no-default-value})
33844 The default value associated for instances of this service type. This
33845 allows users to use the @code{service} form without its second argument:
33848 (service @var{type})
33851 The returned service in this case has the default value specified by
33855 @xref{Service Types and Services}, for examples.
33858 @deffn {Scheme Procedure} service-extension @var{target-type} @
33860 Return a new extension for services of type @var{target-type}.
33861 @var{compute} must be a one-argument procedure: @code{fold-services}
33862 calls it, passing it the value associated with the service that provides
33863 the extension; it must return a valid value for the target service.
33866 @deffn {Scheme Procedure} service-extension? @var{obj}
33867 Return true if @var{obj} is a service extension.
33870 Occasionally, you might want to simply extend an existing service. This
33871 involves creating a new service type and specifying the extension of
33872 interest, which can be verbose; the @code{simple-service} procedure
33873 provides a shorthand for this.
33875 @deffn {Scheme Procedure} simple-service @var{name} @var{target} @var{value}
33876 Return a service that extends @var{target} with @var{value}. This works
33877 by creating a singleton service type @var{name}, of which the returned
33878 service is an instance.
33880 For example, this extends mcron (@pxref{Scheduled Job Execution}) with
33884 (simple-service 'my-mcron-job mcron-service-type
33885 #~(job '(next-hour (3)) "guix gc -F 2G"))
33889 At the core of the service abstraction lies the @code{fold-services}
33890 procedure, which is responsible for ``compiling'' a list of services
33891 down to a single directory that contains everything needed to boot and
33892 run the system---the directory shown by the @command{guix system build}
33893 command (@pxref{Invoking guix system}). In essence, it propagates
33894 service extensions down the service graph, updating each node parameters
33895 on the way, until it reaches the root node.
33897 @deffn {Scheme Procedure} fold-services @var{services} @
33898 [#:target-type @var{system-service-type}]
33899 Fold @var{services} by propagating their extensions down to the root of
33900 type @var{target-type}; return the root service adjusted accordingly.
33903 Lastly, the @code{(gnu services)} module also defines several essential
33904 service types, some of which are listed below.
33906 @defvr {Scheme Variable} system-service-type
33907 This is the root of the service graph. It produces the system directory
33908 as returned by the @command{guix system build} command.
33911 @defvr {Scheme Variable} boot-service-type
33912 The type of the ``boot service'', which produces the @dfn{boot script}.
33913 The boot script is what the initial RAM disk runs when booting.
33916 @defvr {Scheme Variable} etc-service-type
33917 The type of the @file{/etc} service. This service is used to create
33918 files under @file{/etc} and can be extended by
33919 passing it name/file tuples such as:
33922 (list `("issue" ,(plain-file "issue" "Welcome!\n")))
33925 In this example, the effect would be to add an @file{/etc/issue} file
33926 pointing to the given file.
33929 @defvr {Scheme Variable} setuid-program-service-type
33930 Type for the ``setuid-program service''. This service collects lists of
33931 executable file names, passed as gexps, and adds them to the set of
33932 setuid-root programs on the system (@pxref{Setuid Programs}).
33935 @defvr {Scheme Variable} profile-service-type
33936 Type of the service that populates the @dfn{system profile}---i.e., the
33937 programs under @file{/run/current-system/profile}. Other services can
33938 extend it by passing it lists of packages to add to the system profile.
33941 @cindex provenance tracking, of the operating system
33942 @anchor{provenance-service-type}
33943 @defvr {Scheme Variable} provenance-service-type
33944 This is the type of the service that records @dfn{provenance meta-data}
33945 in the system itself. It creates several files under
33946 @file{/run/current-system}:
33950 This is a ``channel file'' that can be passed to @command{guix pull -C}
33951 or @command{guix time-machine -C}, and which describes the channels used
33952 to build the system, if that information was available
33953 (@pxref{Channels}).
33955 @item configuration.scm
33956 This is the file that was passed as the value for this
33957 @code{provenance-service-type} service. By default, @command{guix
33958 system reconfigure} automatically passes the OS configuration file it
33959 received on the command line.
33962 This contains the same information as the two other files but in a
33963 format that is more readily processable.
33966 In general, these two pieces of information (channels and configuration
33967 file) are enough to reproduce the operating system ``from source''.
33970 This information is necessary to rebuild your operating system, but it
33971 is not always sufficient. In particular, @file{configuration.scm}
33972 itself is insufficient if it is not self-contained---if it refers to
33973 external Guile modules or to extra files. If you want
33974 @file{configuration.scm} to be self-contained, we recommend that modules
33975 or files it refers to be part of a channel.
33977 Besides, provenance meta-data is ``silent'' in the sense that it does
33978 not change the bits contained in your system, @emph{except for the
33979 meta-data bits themselves}. Two different OS configurations or sets of
33980 channels can lead to the same system, bit-for-bit; when
33981 @code{provenance-service-type} is used, these two systems will have
33982 different meta-data and thus different store file names, which makes
33983 comparison less trivial.
33986 This service is automatically added to your operating system
33987 configuration when you use @command{guix system reconfigure},
33988 @command{guix system init}, or @command{guix deploy}.
33991 @node Shepherd Services
33992 @subsection Shepherd Services
33994 @cindex shepherd services
33996 @cindex init system
33997 The @code{(gnu services shepherd)} module provides a way to define
33998 services managed by the GNU@tie{}Shepherd, which is the
33999 initialization system---the first process that is started when the
34000 system boots, also known as PID@tie{}1
34001 (@pxref{Introduction,,, shepherd, The GNU Shepherd Manual}).
34003 Services in the Shepherd can depend on each other. For instance, the
34004 SSH daemon may need to be started after the syslog daemon has been
34005 started, which in turn can only happen once all the file systems have
34006 been mounted. The simple operating system defined earlier (@pxref{Using
34007 the Configuration System}) results in a service graph like this:
34009 @image{images/shepherd-graph,,5in,Typical shepherd service graph.}
34011 You can actually generate such a graph for any operating system
34012 definition using the @command{guix system shepherd-graph} command
34013 (@pxref{system-shepherd-graph, @command{guix system shepherd-graph}}).
34015 The @code{%shepherd-root-service} is a service object representing
34016 PID@tie{}1, of type @code{shepherd-root-service-type}; it can be extended
34017 by passing it lists of @code{<shepherd-service>} objects.
34019 @deftp {Data Type} shepherd-service
34020 The data type representing a service managed by the Shepherd.
34023 @item @code{provision}
34024 This is a list of symbols denoting what the service provides.
34026 These are the names that may be passed to @command{herd start},
34027 @command{herd status}, and similar commands (@pxref{Invoking herd,,,
34028 shepherd, The GNU Shepherd Manual}). @xref{Slots of services, the
34029 @code{provides} slot,, shepherd, The GNU Shepherd Manual}, for details.
34031 @item @code{requirement} (default: @code{'()})
34032 List of symbols denoting the Shepherd services this one depends on.
34034 @cindex one-shot services, for the Shepherd
34035 @item @code{one-shot?} (default: @code{#f})
34036 Whether this service is @dfn{one-shot}. One-shot services stop immediately
34037 after their @code{start} action has completed. @xref{Slots of services,,,
34038 shepherd, The GNU Shepherd Manual}, for more info.
34040 @item @code{respawn?} (default: @code{#t})
34041 Whether to restart the service when it stops, for instance when the
34042 underlying process dies.
34045 @itemx @code{stop} (default: @code{#~(const #f)})
34046 The @code{start} and @code{stop} fields refer to the Shepherd's
34047 facilities to start and stop processes (@pxref{Service De- and
34048 Constructors,,, shepherd, The GNU Shepherd Manual}). They are given as
34049 G-expressions that get expanded in the Shepherd configuration file
34050 (@pxref{G-Expressions}).
34052 @item @code{actions} (default: @code{'()})
34053 @cindex actions, of Shepherd services
34054 This is a list of @code{shepherd-action} objects (see below) defining
34055 @dfn{actions} supported by the service, in addition to the standard
34056 @code{start} and @code{stop} actions. Actions listed here become available as
34057 @command{herd} sub-commands:
34060 herd @var{action} @var{service} [@var{arguments}@dots{}]
34063 @item @code{auto-start?} (default: @code{#t})
34064 Whether this service should be started automatically by the Shepherd. If it
34065 is @code{#f} the service has to be started manually with @code{herd start}.
34067 @item @code{documentation}
34068 A documentation string, as shown when running:
34071 herd doc @var{service-name}
34074 where @var{service-name} is one of the symbols in @code{provision}
34075 (@pxref{Invoking herd,,, shepherd, The GNU Shepherd Manual}).
34077 @item @code{modules} (default: @code{%default-modules})
34078 This is the list of modules that must be in scope when @code{start} and
34079 @code{stop} are evaluated.
34084 The example below defines a Shepherd service that spawns
34085 @command{syslogd}, the system logger from the GNU Networking Utilities
34086 (@pxref{syslogd invocation, @command{syslogd},, inetutils, GNU
34090 (let ((config (plain-file "syslogd.conf" "@dots{}")))
34092 (documentation "Run the syslog daemon (syslogd).")
34093 (provision '(syslogd))
34094 (requirement '(user-processes))
34095 (start #~(make-forkexec-constructor
34096 (list #$(file-append inetutils "/libexec/syslogd")
34097 "--rcfile" #$config)
34098 #:pid-file "/var/run/syslog.pid"))
34099 (stop #~(make-kill-destructor))))
34102 Key elements in this example are the @code{start} and @code{stop}
34103 fields: they are @dfn{staged} code snippets that use the
34104 @code{make-forkexec-constructor} procedure provided by the Shepherd and
34105 its dual, @code{make-kill-destructor} (@pxref{Service De- and
34106 Constructors,,, shepherd, The GNU Shepherd Manual}). The @code{start}
34107 field will have @command{shepherd} spawn @command{syslogd} with the
34108 given option; note that we pass @code{config} after @option{--rcfile},
34109 which is a configuration file declared above (contents of this file are
34110 omitted). Likewise, the @code{stop} field tells how this service is to
34111 be stopped; in this case, it is stopped by making the @code{kill} system
34112 call on its PID@. Code staging is achieved using G-expressions:
34113 @code{#~} stages code, while @code{#$} ``escapes'' back to host code
34114 (@pxref{G-Expressions}).
34116 @deftp {Data Type} shepherd-action
34117 This is the data type that defines additional actions implemented by a
34118 Shepherd service (see above).
34122 Symbol naming the action.
34124 @item documentation
34125 This is a documentation string for the action. It can be viewed by running:
34128 herd doc @var{service} action @var{action}
34132 This should be a gexp that evaluates to a procedure of at least one argument,
34133 which is the ``running value'' of the service (@pxref{Slots of services,,,
34134 shepherd, The GNU Shepherd Manual}).
34137 The following example defines an action called @code{say-hello} that kindly
34143 (documentation "Say hi!")
34144 (procedure #~(lambda (running . args)
34145 (format #t "Hello, friend! arguments: ~s\n"
34150 Assuming this action is added to the @code{example} service, then you can do:
34153 # herd say-hello example
34154 Hello, friend! arguments: ()
34155 # herd say-hello example a b c
34156 Hello, friend! arguments: ("a" "b" "c")
34159 This, as you can see, is a fairly sophisticated way to say hello.
34160 @xref{Service Convenience,,, shepherd, The GNU Shepherd Manual}, for more
34164 @defvr {Scheme Variable} shepherd-root-service-type
34165 The service type for the Shepherd ``root service''---i.e., PID@tie{}1.
34167 This is the service type that extensions target when they want to create
34168 shepherd services (@pxref{Service Types and Services}, for an example).
34169 Each extension must pass a list of @code{<shepherd-service>}. Its
34170 value must be a @code{shepherd-configuration}, as described below.
34173 @deftp {Data Type} shepherd-configuration
34174 This data type represents the Shepherd's configuration.
34177 @item shepherd (default: @code{shepherd})
34178 The Shepherd package to use.
34180 @item services (default: @code{'()})
34181 A list of @code{<shepherd-service>} to start.
34182 You should probably use the service extension
34183 mechanism instead (@pxref{Shepherd Services}).
34187 The following example specifies the Shepherd package for the operating
34193 (services (append (list openssh-service-type))
34197 ;; Use own Shepherd package.
34198 (essential-services
34199 (modify-services (operating-system-default-essential-services
34200 this-operating-system)
34201 (shepherd-root-service-type config => (shepherd-configuration
34203 (shepherd my-shepherd))))))
34206 @defvr {Scheme Variable} %shepherd-root-service
34207 This service represents PID@tie{}1.
34211 @node Documentation
34212 @chapter Documentation
34214 @cindex documentation, searching for
34215 @cindex searching for documentation
34216 @cindex Info, documentation format
34218 @cindex manual pages
34219 In most cases packages installed with Guix come with documentation.
34220 There are two main documentation formats: ``Info'', a browseable
34221 hypertext format used for GNU software, and ``manual pages'' (or ``man
34222 pages''), the linear documentation format traditionally found on Unix.
34223 Info manuals are accessed with the @command{info} command or with Emacs,
34224 and man pages are accessed using @command{man}.
34226 You can look for documentation of software installed on your system by
34227 keyword. For example, the following command searches for information
34228 about ``TLS'' in Info manuals:
34232 "(emacs)Network Security" -- STARTTLS
34233 "(emacs)Network Security" -- TLS
34234 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_flags
34235 "(gnutls)Core TLS API" -- gnutls_certificate_set_verify_function
34240 The command below searches for the same keyword in man pages:
34244 SSL (7) - OpenSSL SSL/TLS library
34245 certtool (1) - GnuTLS certificate tool
34249 These searches are purely local to your computer so you have the
34250 guarantee that documentation you find corresponds to what you have
34251 actually installed, you can access it off-line, and your privacy is
34254 Once you have these results, you can view the relevant documentation by
34258 $ info "(gnutls)Core TLS API"
34268 Info manuals contain sections and indices as well as hyperlinks like
34269 those found in Web pages. The @command{info} reader (@pxref{Top, Info
34270 reader,, info-stnd, Stand-alone GNU Info}) and its Emacs counterpart
34271 (@pxref{Misc Help,,, emacs, The GNU Emacs Manual}) provide intuitive key
34272 bindings to navigate manuals. @xref{Getting Started,,, info, Info: An
34273 Introduction}, for an introduction to Info navigation.
34275 @node Installing Debugging Files
34276 @chapter Installing Debugging Files
34278 @cindex debugging files
34279 Program binaries, as produced by the GCC compilers for instance, are
34280 typically written in the ELF format, with a section containing
34281 @dfn{debugging information}. Debugging information is what allows the
34282 debugger, GDB, to map binary code to source code; it is required to
34283 debug a compiled program in good conditions.
34285 This chapter explains how to use separate debug info when packages
34286 provide it, and how to rebuild packages with debug info when it's
34290 * Separate Debug Info:: Installing 'debug' outputs.
34291 * Rebuilding Debug Info:: Building missing debug info.
34294 @node Separate Debug Info
34295 @section Separate Debug Info
34297 The problem with debugging information is that is takes up a fair amount
34298 of disk space. For example, debugging information for the GNU C Library
34299 weighs in at more than 60 MiB@. Thus, as a user, keeping all the
34300 debugging info of all the installed programs is usually not an option.
34301 Yet, space savings should not come at the cost of an impediment to
34302 debugging---especially in the GNU system, which should make it easier
34303 for users to exert their computing freedom (@pxref{GNU Distribution}).
34305 Thankfully, the GNU Binary Utilities (Binutils) and GDB provide a
34306 mechanism that allows users to get the best of both worlds: debugging
34307 information can be stripped from the binaries and stored in separate
34308 files. GDB is then able to load debugging information from those files,
34309 when they are available (@pxref{Separate Debug Files,,, gdb, Debugging
34312 The GNU distribution takes advantage of this by storing debugging
34313 information in the @code{lib/debug} sub-directory of a separate package
34314 output unimaginatively called @code{debug} (@pxref{Packages with
34315 Multiple Outputs}). Users can choose to install the @code{debug} output
34316 of a package when they need it. For instance, the following command
34317 installs the debugging information for the GNU C Library and for GNU
34321 guix install glibc:debug guile:debug
34324 GDB must then be told to look for debug files in the user's profile, by
34325 setting the @code{debug-file-directory} variable (consider setting it
34326 from the @file{~/.gdbinit} file, @pxref{Startup,,, gdb, Debugging with
34330 (gdb) set debug-file-directory ~/.guix-profile/lib/debug
34333 From there on, GDB will pick up debugging information from the
34334 @file{.debug} files under @file{~/.guix-profile/lib/debug}.
34336 In addition, you will most likely want GDB to be able to show the source
34337 code being debugged. To do that, you will have to unpack the source
34338 code of the package of interest (obtained with @code{guix build
34339 --source}, @pxref{Invoking guix build}), and to point GDB to that source
34340 directory using the @code{directory} command (@pxref{Source Path,
34341 @code{directory},, gdb, Debugging with GDB}).
34343 @c XXX: keep me up-to-date
34344 The @code{debug} output mechanism in Guix is implemented by the
34345 @code{gnu-build-system} (@pxref{Build Systems}). Currently, it is
34346 opt-in---debugging information is available only for the packages with
34347 definitions explicitly declaring a @code{debug} output. To check
34348 whether a package has a @code{debug} output, use @command{guix package
34349 --list-available} (@pxref{Invoking guix package}).
34351 Read on for how to deal with packages lacking a @code{debug} output.
34353 @node Rebuilding Debug Info
34354 @section Rebuilding Debug Info
34356 @cindex debugging info, rebuilding
34357 As we saw above, some packages, but not all, provide debugging info in a
34358 @code{debug} output. What can you do when debugging info is missing?
34359 The @option{--with-debug-info} option provides a solution to that: it
34360 allows you to rebuild the package(s) for which debugging info is
34361 missing---and only those---and to graft those onto the application
34362 you're debugging. Thus, while it's not as fast as installing a
34363 @code{debug} output, it is relatively inexpensive.
34365 Let's illustrate that. Suppose you're experiencing a bug in Inkscape
34366 and would like to see what's going on in GLib, a library that's deep
34367 down in its dependency graph. As it turns out, GLib does not have a
34368 @code{debug} output and the backtrace GDB shows is all sadness:
34372 #0 0x00007ffff5f92190 in g_getenv ()
34373 from /gnu/store/@dots{}-glib-2.62.6/lib/libglib-2.0.so.0
34374 #1 0x00007ffff608a7d6 in gobject_init_ctor ()
34375 from /gnu/store/@dots{}-glib-2.62.6/lib/libgobject-2.0.so.0
34376 #2 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=1, argv=argv@@entry=0x7fffffffcfd8,
34377 env=env@@entry=0x7fffffffcfe8) at dl-init.c:72
34378 #3 0x00007ffff7fe2866 in call_init (env=0x7fffffffcfe8, argv=0x7fffffffcfd8, argc=1, l=<optimized out>)
34382 To address that, you install Inkscape linked against a variant GLib that
34383 contains debug info:
34386 guix install inkscape --with-debug-info=glib
34389 This time, debugging will be a whole lot nicer:
34392 $ gdb --args sh -c 'exec inkscape'
34395 Function "g_getenv" not defined.
34396 Make breakpoint pending on future shared library load? (y or [n]) y
34397 Breakpoint 1 (g_getenv) pending.
34399 Starting program: /gnu/store/@dots{}-profile/bin/sh -c exec\ inkscape
34402 #0 g_getenv (variable=variable@@entry=0x7ffff60c7a2e "GOBJECT_DEBUG") at ../glib-2.62.6/glib/genviron.c:252
34403 #1 0x00007ffff608a7d6 in gobject_init () at ../glib-2.62.6/gobject/gtype.c:4380
34404 #2 gobject_init_ctor () at ../glib-2.62.6/gobject/gtype.c:4493
34405 #3 0x00007ffff7fe275a in call_init (l=<optimized out>, argc=argc@@entry=3, argv=argv@@entry=0x7fffffffd088,
34406 env=env@@entry=0x7fffffffd0a8) at dl-init.c:72
34412 Note that there can be packages for which @option{--with-debug-info}
34413 will not have the desired effect. @xref{Package Transformation Options,
34414 @option{--with-debug-info}}, for more information.
34416 @node Security Updates
34417 @chapter Security Updates
34419 @cindex security updates
34420 @cindex security vulnerabilities
34421 Occasionally, important security vulnerabilities are discovered in software
34422 packages and must be patched. Guix developers try hard to keep track of
34423 known vulnerabilities and to apply fixes as soon as possible in the
34424 @code{master} branch of Guix (we do not yet provide a ``stable'' branch
34425 containing only security updates). The @command{guix lint} tool helps
34426 developers find out about vulnerable versions of software packages in the
34431 gnu/packages/base.scm:652:2: glibc@@2.21: probably vulnerable to CVE-2015-1781, CVE-2015-7547
34432 gnu/packages/gcc.scm:334:2: gcc@@4.9.3: probably vulnerable to CVE-2015-5276
34433 gnu/packages/image.scm:312:2: openjpeg@@2.1.0: probably vulnerable to CVE-2016-1923, CVE-2016-1924
34437 @xref{Invoking guix lint}, for more information.
34439 Guix follows a functional
34440 package management discipline (@pxref{Introduction}), which implies
34441 that, when a package is changed, @emph{every package that depends on it}
34442 must be rebuilt. This can significantly slow down the deployment of
34443 fixes in core packages such as libc or Bash, since basically the whole
34444 distribution would need to be rebuilt. Using pre-built binaries helps
34445 (@pxref{Substitutes}), but deployment may still take more time than
34449 To address this, Guix implements @dfn{grafts}, a mechanism that allows
34450 for fast deployment of critical updates without the costs associated
34451 with a whole-distribution rebuild. The idea is to rebuild only the
34452 package that needs to be patched, and then to ``graft'' it onto packages
34453 explicitly installed by the user and that were previously referring to
34454 the original package. The cost of grafting is typically very low, and
34455 order of magnitudes lower than a full rebuild of the dependency chain.
34457 @cindex replacements of packages, for grafts
34458 For instance, suppose a security update needs to be applied to Bash.
34459 Guix developers will provide a package definition for the ``fixed''
34460 Bash, say @code{bash-fixed}, in the usual way (@pxref{Defining
34461 Packages}). Then, the original package definition is augmented with a
34462 @code{replacement} field pointing to the package containing the bug fix:
34469 (replacement bash-fixed)))
34472 From there on, any package depending directly or indirectly on Bash---as
34473 reported by @command{guix gc --requisites} (@pxref{Invoking guix
34474 gc})---that is installed is automatically ``rewritten'' to refer to
34475 @code{bash-fixed} instead of @code{bash}. This grafting process takes
34476 time proportional to the size of the package, usually less than a
34477 minute for an ``average'' package on a recent machine. Grafting is
34478 recursive: when an indirect dependency requires grafting, then grafting
34479 ``propagates'' up to the package that the user is installing.
34481 Currently, the length of the name and version of the graft and that of
34482 the package it replaces (@code{bash-fixed} and @code{bash} in the example
34483 above) must be equal. This restriction mostly comes from the fact that
34484 grafting works by patching files, including binary files, directly.
34485 Other restrictions may apply: for instance, when adding a graft to a
34486 package providing a shared library, the original shared library and its
34487 replacement must have the same @code{SONAME} and be binary-compatible.
34489 The @option{--no-grafts} command-line option allows you to forcefully
34490 avoid grafting (@pxref{Common Build Options, @option{--no-grafts}}).
34494 guix build bash --no-grafts
34498 returns the store file name of the original Bash, whereas:
34505 returns the store file name of the ``fixed'', replacement Bash. This
34506 allows you to distinguish between the two variants of Bash.
34508 To verify which Bash your whole profile refers to, you can run
34509 (@pxref{Invoking guix gc}):
34512 guix gc -R `readlink -f ~/.guix-profile` | grep bash
34516 @dots{} and compare the store file names that you get with those above.
34517 Likewise for a complete Guix system generation:
34520 guix gc -R `guix system build my-config.scm` | grep bash
34523 Lastly, to check which Bash running processes are using, you can use the
34524 @command{lsof} command:
34527 lsof | grep /gnu/store/.*bash
34531 @node Bootstrapping
34532 @chapter Bootstrapping
34534 @c Adapted from the ELS 2013 paper.
34536 @cindex bootstrapping
34538 Bootstrapping in our context refers to how the distribution gets built
34539 ``from nothing''. Remember that the build environment of a derivation
34540 contains nothing but its declared inputs (@pxref{Introduction}). So
34541 there's an obvious chicken-and-egg problem: how does the first package
34542 get built? How does the first compiler get compiled?
34544 It is tempting to think of this question as one that only die-hard
34545 hackers may care about. However, while the answer to that question is
34546 technical in nature, its implications are wide-ranging. How the
34547 distribution is bootstrapped defines the extent to which we, as
34548 individuals and as a collective of users and hackers, can trust the
34549 software we run. It is a central concern from the standpoint of
34550 @emph{security} and from a @emph{user freedom} viewpoint.
34552 @cindex bootstrap binaries
34553 The GNU system is primarily made of C code, with libc at its core. The
34554 GNU build system itself assumes the availability of a Bourne shell and
34555 command-line tools provided by GNU Coreutils, Awk, Findutils, `sed', and
34556 `grep'. Furthermore, build programs---programs that run
34557 @code{./configure}, @code{make}, etc.---are written in Guile Scheme
34558 (@pxref{Derivations}). Consequently, to be able to build anything at
34559 all, from scratch, Guix relies on pre-built binaries of Guile, GCC,
34560 Binutils, libc, and the other packages mentioned above---the
34561 @dfn{bootstrap binaries}.
34563 These bootstrap binaries are ``taken for granted'', though we can also
34564 re-create them if needed (@pxref{Preparing to Use the Bootstrap
34568 * Reduced Binary Seed Bootstrap:: A Bootstrap worthy of GNU.
34569 * Preparing to Use the Bootstrap Binaries:: Building that what matters most.
34572 @node Reduced Binary Seed Bootstrap
34573 @section The Reduced Binary Seed Bootstrap
34575 Guix---like other GNU/Linux distributions---is traditionally bootstrapped from
34576 a set of bootstrap binaries: Bourne shell, command-line tools provided by GNU
34577 Coreutils, Awk, Findutils, `sed', and `grep' and Guile, GCC, Binutils, and the
34578 GNU C Library (@pxref{Bootstrapping}). Usually, these bootstrap binaries are
34579 ``taken for granted.''
34581 Taking the bootstrap binaries for granted means that we consider them to
34582 be a correct and trustworthy ``seed'' for building the complete system.
34583 Therein lies a problem: the combined size of these bootstrap binaries is
34584 about 250MB (@pxref{Bootstrappable Builds,,, mes, GNU Mes}). Auditing
34585 or even inspecting these is next to impossible.
34587 For @code{i686-linux} and @code{x86_64-linux}, Guix now features a
34588 ``Reduced Binary Seed'' bootstrap @footnote{We would like to say: ``Full
34589 Source Bootstrap'' and while we are working towards that goal it would
34590 be hyperbole to use that term for what we do now.}.
34592 The Reduced Binary Seed bootstrap removes the most critical tools---from a
34593 trust perspective---from the bootstrap binaries: GCC, Binutils and the GNU C
34594 Library are replaced by: @code{bootstrap-mescc-tools} (a tiny assembler and
34595 linker) and @code{bootstrap-mes} (a small Scheme Interpreter and a C compiler
34596 written in Scheme and the Mes C Library, built for TinyCC and for GCC).
34598 Using these new binary seeds the ``missing'' Binutils, GCC, and the GNU
34599 C Library are built from source. From here on the more traditional
34600 bootstrap process resumes. This approach has reduced the bootstrap
34601 binaries in size to about 145MB in Guix v1.1.
34603 The next step that Guix has taken is to replace the shell and all its
34604 utilities with implementations in Guile Scheme, the @emph{Scheme-only
34605 bootstrap}. Gash (@pxref{Gash,,, gash, The Gash manual}) is a
34606 POSIX-compatible shell that replaces Bash, and it comes with Gash Utils
34607 which has minimalist replacements for Awk, the GNU Core Utilities, Grep,
34608 Gzip, Sed, and Tar. The rest of the bootstrap binary seeds that were
34609 removed are now built from source.
34611 Building the GNU System from source is currently only possible by adding
34612 some historical GNU packages as intermediate steps@footnote{Packages
34613 such as @code{gcc-2.95.3}, @code{binutils-2.14}, @code{glibc-2.2.5},
34614 @code{gzip-1.2.4}, @code{tar-1.22}, and some others. For details, see
34615 @file{gnu/packages/commencement.scm}.}. As Gash and Gash Utils mature,
34616 and GNU packages become more bootstrappable again (e.g., new releases of
34617 GNU Sed will also ship as gzipped tarballs again, as alternative to the
34618 hard to bootstrap @code{xz}-compression), this set of added packages can
34619 hopefully be reduced again.
34621 The graph below shows the resulting dependency graph for
34622 @code{gcc-core-mesboot0}, the bootstrap compiler used for the
34623 traditional bootstrap of the rest of the Guix System.
34625 @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
34626 @image{images/gcc-core-mesboot0-graph,6in,,Dependency graph of gcc-core-mesboot0}
34628 The only significant binary bootstrap seeds that remain@footnote{
34629 Ignoring the 68KB @code{mescc-tools}; that will be removed later,
34630 together with @code{mes}.} are a Scheme intepreter and a Scheme
34631 compiler: GNU Mes and GNU Guile@footnote{Not shown in this graph are the
34632 static binaries for @file{bash}, @code{tar}, and @code{xz} that are used
34633 to get Guile running.}.
34635 This further reduction has brought down the size of the binary seed to
34636 about 60MB for @code{i686-linux} and @code{x86_64-linux}.
34638 Work is ongoing to remove all binary blobs from our free software
34639 bootstrap stack, working towards a Full Source Bootstrap. Also ongoing
34640 is work to bring these bootstraps to the @code{arm-linux} and
34641 @code{aarch64-linux} architectures and to the Hurd.
34643 If you are interested, join us on @samp{#bootstrappable} on the Freenode
34644 IRC network or discuss on @email{bug-mes@@gnu.org} or
34645 @email{gash-devel@@nongnu.org}.
34647 @node Preparing to Use the Bootstrap Binaries
34648 @section Preparing to Use the Bootstrap Binaries
34650 @c As of Emacs 24.3, Info-mode displays the image, but since it's a
34651 @c large image, it's hard to scroll. Oh well.
34652 @image{images/bootstrap-graph,6in,,Dependency graph of the early bootstrap derivations}
34654 The figure above shows the very beginning of the dependency graph of the
34655 distribution, corresponding to the package definitions of the @code{(gnu
34656 packages bootstrap)} module. A similar figure can be generated with
34657 @command{guix graph} (@pxref{Invoking guix graph}), along the lines of:
34660 guix graph -t derivation \
34661 -e '(@@@@ (gnu packages bootstrap) %bootstrap-gcc)' \
34662 | dot -Tps > gcc.ps
34665 or, for the further Reduced Binary Seed bootstrap
34668 guix graph -t derivation \
34669 -e '(@@@@ (gnu packages bootstrap) %bootstrap-mes)' \
34670 | dot -Tps > mes.ps
34673 At this level of detail, things are
34674 slightly complex. First, Guile itself consists of an ELF executable,
34675 along with many source and compiled Scheme files that are dynamically
34676 loaded when it runs. This gets stored in the @file{guile-2.0.7.tar.xz}
34677 tarball shown in this graph. This tarball is part of Guix's ``source''
34678 distribution, and gets inserted into the store with @code{add-to-store}
34679 (@pxref{The Store}).
34681 But how do we write a derivation that unpacks this tarball and adds it
34682 to the store? To solve this problem, the @code{guile-bootstrap-2.0.drv}
34683 derivation---the first one that gets built---uses @code{bash} as its
34684 builder, which runs @code{build-bootstrap-guile.sh}, which in turn calls
34685 @code{tar} to unpack the tarball. Thus, @file{bash}, @file{tar},
34686 @file{xz}, and @file{mkdir} are statically-linked binaries, also part of
34687 the Guix source distribution, whose sole purpose is to allow the Guile
34688 tarball to be unpacked.
34690 Once @code{guile-bootstrap-2.0.drv} is built, we have a functioning
34691 Guile that can be used to run subsequent build programs. Its first task
34692 is to download tarballs containing the other pre-built binaries---this
34693 is what the @file{.tar.xz.drv} derivations do. Guix modules such as
34694 @code{ftp-client.scm} are used for this purpose. The
34695 @code{module-import.drv} derivations import those modules in a directory
34696 in the store, using the original layout. The
34697 @code{module-import-compiled.drv} derivations compile those modules, and
34698 write them in an output directory with the right layout. This
34699 corresponds to the @code{#:modules} argument of
34700 @code{build-expression->derivation} (@pxref{Derivations}).
34702 Finally, the various tarballs are unpacked by the derivations
34703 @code{gcc-bootstrap-0.drv}, @code{glibc-bootstrap-0.drv}, or
34704 @code{bootstrap-mes-0.drv} and @code{bootstrap-mescc-tools-0.drv}, at which
34705 point we have a working C tool chain.
34707 @unnumberedsec Building the Build Tools
34709 Bootstrapping is complete when we have a full tool chain that does not
34710 depend on the pre-built bootstrap tools discussed above. This
34711 no-dependency requirement is verified by checking whether the files of
34712 the final tool chain contain references to the @file{/gnu/store}
34713 directories of the bootstrap inputs. The process that leads to this
34714 ``final'' tool chain is described by the package definitions found in
34715 the @code{(gnu packages commencement)} module.
34717 The @command{guix graph} command allows us to ``zoom out'' compared to
34718 the graph above, by looking at the level of package objects instead of
34719 individual derivations---remember that a package may translate to
34720 several derivations, typically one derivation to download its source,
34721 one to build the Guile modules it needs, and one to actually build the
34722 package from source. The command:
34725 guix graph -t bag \
34726 -e '(@@@@ (gnu packages commencement)
34727 glibc-final-with-bootstrap-bash)' | xdot -
34731 displays the dependency graph leading to the ``final'' C
34732 library@footnote{You may notice the @code{glibc-intermediate} label,
34733 suggesting that it is not @emph{quite} final, but as a good
34734 approximation, we will consider it final.}, depicted below.
34736 @image{images/bootstrap-packages,6in,,Dependency graph of the early packages}
34738 @c See <https://lists.gnu.org/archive/html/gnu-system-discuss/2012-10/msg00000.html>.
34739 The first tool that gets built with the bootstrap binaries is
34740 GNU@tie{}Make---noted @code{make-boot0} above---which is a prerequisite
34741 for all the following packages. From there Findutils and Diffutils get
34744 Then come the first-stage Binutils and GCC, built as pseudo cross
34745 tools---i.e., with @option{--target} equal to @option{--host}. They are
34746 used to build libc. Thanks to this cross-build trick, this libc is
34747 guaranteed not to hold any reference to the initial tool chain.
34749 From there the final Binutils and GCC (not shown above) are built. GCC
34750 uses @command{ld} from the final Binutils, and links programs against
34751 the just-built libc. This tool chain is used to build the other
34752 packages used by Guix and by the GNU Build System: Guile, Bash,
34755 And voilà! At this point we have the complete set of build tools that
34756 the GNU Build System expects. These are in the @code{%final-inputs}
34757 variable of the @code{(gnu packages commencement)} module, and are
34758 implicitly used by any package that uses @code{gnu-build-system}
34759 (@pxref{Build Systems, @code{gnu-build-system}}).
34762 @unnumberedsec Building the Bootstrap Binaries
34764 @cindex bootstrap binaries
34765 Because the final tool chain does not depend on the bootstrap binaries,
34766 those rarely need to be updated. Nevertheless, it is useful to have an
34767 automated way to produce them, should an update occur, and this is what
34768 the @code{(gnu packages make-bootstrap)} module provides.
34770 The following command builds the tarballs containing the bootstrap binaries
34771 (Binutils, GCC, glibc, for the traditional bootstrap and linux-libre-headers,
34772 bootstrap-mescc-tools, bootstrap-mes for the Reduced Binary Seed bootstrap,
34773 and Guile, and a tarball containing a mixture of Coreutils and other basic
34774 command-line tools):
34777 guix build bootstrap-tarballs
34780 The generated tarballs are those that should be referred to in the
34781 @code{(gnu packages bootstrap)} module mentioned at the beginning of
34784 Still here? Then perhaps by now you've started to wonder: when do we
34785 reach a fixed point? That is an interesting question! The answer is
34786 unknown, but if you would like to investigate further (and have
34787 significant computational and storage resources to do so), then let us
34790 @unnumberedsec Reducing the Set of Bootstrap Binaries
34792 Our traditional bootstrap includes GCC, GNU Libc, Guile, etc. That's a lot of
34793 binary code! Why is that a problem? It's a problem because these big chunks
34794 of binary code are practically non-auditable, which makes it hard to establish
34795 what source code produced them. Every unauditable binary also leaves us
34796 vulnerable to compiler backdoors as described by Ken Thompson in the 1984
34797 paper @emph{Reflections on Trusting Trust}.
34799 This is mitigated by the fact that our bootstrap binaries were generated
34800 from an earlier Guix revision. Nevertheless it lacks the level of
34801 transparency that we get in the rest of the package dependency graph,
34802 where Guix always gives us a source-to-binary mapping. Thus, our goal
34803 is to reduce the set of bootstrap binaries to the bare minimum.
34805 The @uref{https://bootstrappable.org, Bootstrappable.org web site} lists
34806 on-going projects to do that. One of these is about replacing the
34807 bootstrap GCC with a sequence of assemblers, interpreters, and compilers
34808 of increasing complexity, which could be built from source starting from
34809 a simple and auditable assembler.
34811 Our first major achievement is the replacement of of GCC, the GNU C Library
34812 and Binutils by MesCC-Tools (a simple hex linker and macro assembler) and Mes
34813 (@pxref{Top, GNU Mes Reference Manual,, mes, GNU Mes}, a Scheme interpreter
34814 and C compiler in Scheme). Neither MesCC-Tools nor Mes can be fully
34815 bootstrapped yet and thus we inject them as binary seeds. We call this the
34816 Reduced Binary Seed bootstrap, as it has halved the size of our bootstrap
34817 binaries! Also, it has eliminated the C compiler binary; i686-linux and
34818 x86_64-linux Guix packages are now bootstrapped without any binary C compiler.
34820 Work is ongoing to make MesCC-Tools and Mes fully bootstrappable and we are
34821 also looking at any other bootstrap binaries. Your help is welcome!
34824 @chapter Porting to a New Platform
34826 As discussed above, the GNU distribution is self-contained, and
34827 self-containment is achieved by relying on pre-built ``bootstrap
34828 binaries'' (@pxref{Bootstrapping}). These binaries are specific to an
34829 operating system kernel, CPU architecture, and application binary
34830 interface (ABI). Thus, to port the distribution to a platform that is
34831 not yet supported, one must build those bootstrap binaries, and update
34832 the @code{(gnu packages bootstrap)} module to use them on that platform.
34834 Fortunately, Guix can @emph{cross compile} those bootstrap binaries.
34835 When everything goes well, and assuming the GNU tool chain supports the
34836 target platform, this can be as simple as running a command like this
34840 guix build --target=armv5tel-linux-gnueabi bootstrap-tarballs
34843 For this to work, the @code{glibc-dynamic-linker} procedure in
34844 @code{(gnu packages bootstrap)} must be augmented to return the right
34845 file name for libc's dynamic linker on that platform; likewise,
34846 @code{system->linux-architecture} in @code{(gnu packages linux)} must be
34847 taught about the new platform.
34849 Once these are built, the @code{(gnu packages bootstrap)} module needs
34850 to be updated to refer to these binaries on the target platform. That
34851 is, the hashes and URLs of the bootstrap tarballs for the new platform
34852 must be added alongside those of the currently supported platforms. The
34853 bootstrap Guile tarball is treated specially: it is expected to be
34854 available locally, and @file{gnu/local.mk} has rules to download it for
34855 the supported architectures; a rule for the new platform must be added
34858 In practice, there may be some complications. First, it may be that the
34859 extended GNU triplet that specifies an ABI (like the @code{eabi} suffix
34860 above) is not recognized by all the GNU tools. Typically, glibc
34861 recognizes some of these, whereas GCC uses an extra @option{--with-abi}
34862 configure flag (see @code{gcc.scm} for examples of how to handle this).
34863 Second, some of the required packages could fail to build for that
34864 platform. Lastly, the generated binaries could be broken for some
34867 @c *********************************************************************
34868 @include contributing.texi
34870 @c *********************************************************************
34871 @node Acknowledgments
34872 @chapter Acknowledgments
34874 Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
34875 which was designed and
34876 implemented by Eelco Dolstra, with contributions from other people (see
34877 the @file{nix/AUTHORS} file in Guix). Nix pioneered functional package
34878 management, and promoted unprecedented features, such as transactional
34879 package upgrades and rollbacks, per-user profiles, and referentially
34880 transparent build processes. Without this work, Guix would not exist.
34882 The Nix-based software distributions, Nixpkgs and NixOS, have also been
34883 an inspiration for Guix.
34885 GNU@tie{}Guix itself is a collective work with contributions from a
34886 number of people. See the @file{AUTHORS} file in Guix for more
34887 information on these fine people. The @file{THANKS} file lists people
34888 who have helped by reporting bugs, taking care of the infrastructure,
34889 providing artwork and themes, making suggestions, and more---thank you!
34892 @c *********************************************************************
34893 @node GNU Free Documentation License
34894 @appendix GNU Free Documentation License
34895 @cindex license, GNU Free Documentation License
34896 @include fdl-1.3.texi
34898 @c *********************************************************************
34899 @node Concept Index
34900 @unnumbered Concept Index
34903 @node Programming Index
34904 @unnumbered Programming Index
34905 @syncodeindex tp fn
34906 @syncodeindex vr fn
34911 @c Local Variables:
34912 @c ispell-local-dictionary: "american";