WIP Guix Cookbook

[Ricardo Wurmus]

Hi Guix,

attached is a WIP patch for a Guix Cookbook, a document that is intended
to include articles, tutorials, and annotated examples with links to the
reference manual.  The idea is that the reference manual shouldn’t be
bloated with examples and tutorials, but we’d also like to ensure high
quality control and a document that can easily be adjusted to match the
changing APIs.

This initial draft includes parts of Pierre’s packaging tutorial and
Efraim’s article on customizing the kernel.  As I was preparing this I
had some doubts about my choices.  The kernel article highlights
problems with our API, which makes customizing the kernel somewhat
awkward.  The packaging tutorial on the other hand is very large and
includes a Scheme tutorial.  Maybe this should be moved to a separate
section…?

Efraim’s original article uses the first person as the narrator voice,
which is fine for a blog post, but maybe not appropriate for a
collaborative document.  Should this be changed?

What do you think?

@Julien: I tried my best to set up the translation machinery, but I’m
not convinced I did it all correctly.  Sometimes during my test a few
translation texi file ended up without any but the generated contents
(i.e. the one stating the file name).  Other times it seems to work fine
and the English document contents are copied over.  Could you please
check that this is working correctly?

--
Ricardo

>From 880e367ccdd8144b8f9392a308411bf51cab692e Mon Sep 17 00:00:00 2001
From: Ricardo Wurmus <address@hidden>
Date: Sun, 8 Sep 2019 14:35:44 +0200
Subject: [PATCH] WIP Add Guix Cookbook.

---
 .gitignore             |  30 +-
 bootstrap              |   9 +-
 doc/guix-cookbook.texi | 807 +++++++++++++++++++++++++++++++++++++++++
 doc/local.mk           |  19 +-
 po/doc/local.mk        |  38 +-
 5 files changed, 885 insertions(+), 18 deletions(-)
 create mode 100644 doc/guix-cookbook.texi

diff --git a/.gitignore b/.gitignore
index 93d2ec9801..73997e8b4c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -29,21 +29,21 @@
 /doc/*.1
 /doc/.dirstamp
 /doc/contributing.*.texi
-/doc/guix.*.aux
-/doc/guix.*.cp
-/doc/guix.*.cps
-/doc/guix.*.fn
-/doc/guix.*.fns
-/doc/guix.*.html
-/doc/guix.*.info
-/doc/guix.*.info-[0-9]
-/doc/guix.*.ky
-/doc/guix.*.pg
-/doc/guix.*.toc
-/doc/guix.*.t2p
-/doc/guix.*.tp
-/doc/guix.*.vr
-/doc/guix.*.vrs
+/doc/guix*.aux
+/doc/guix*.cp
+/doc/guix*.cps
+/doc/guix*.fn
+/doc/guix*.fns
+/doc/guix*.html
+/doc/guix*.info
+/doc/guix*.info-[0-9]
+/doc/guix*.ky
+/doc/guix*.pg
+/doc/guix*.toc
+/doc/guix*.t2p
+/doc/guix*.tp
+/doc/guix*.vr
+/doc/guix*.vrs
 /doc/guix.*.texi
 /doc/guix.aux
 /doc/guix.cp
diff --git a/bootstrap b/bootstrap
index c0b5af7677..19dfd701a3 100755
--- a/bootstrap
+++ b/bootstrap
@@ -4,7 +4,7 @@
 set -e -x
 
 # Generate stubs for translations.
-langs=`find po/doc -type f -name '*.po' \
+langs=`find po/doc -type f -name 'guix-manual*.po' \
         | sed -e 's,guix-manual\.,,' \
         | xargs -n 1 -I{} basename {} .po`
 for lang in ${langs}; do
@@ -15,5 +15,12 @@ for lang in ${langs}; do
        touch "po/doc/guix-manual.${lang}.po"
     fi
 done
+for lang in ${langs}; do
+    if [ ! -e "doc/guix-cookbook.${lang}.texi" ]; then
+       echo "@setfilename guix-cookbook.${lang}.info" > 
"doc/guix-cookbook.${lang}.texi"
+       # Ensure .po file is newer.
+       touch "po/doc/guix-cookbook.${lang}.po"
+    fi
+done
 
 exec autoreconf -vfi
diff --git a/doc/guix-cookbook.texi b/doc/guix-cookbook.texi
new file mode 100644
index 0000000000..3b7bfbc9a7
--- /dev/null
+++ b/doc/guix-cookbook.texi
@@ -0,0 +1,807 @@
+\input texinfo
+@c -*-texinfo-*-
+
+@c %**start of header
+@setfilename guix-cookbook.info
+@documentencoding UTF-8
+@settitle GNU Guix Cookbook
+@c %**end of header
+
+@copying
+Copyright @copyright{} 2019 Ricardo Wurmus@*
+Copyright @copyright{} 2019 Efraim Flashner@*
+Copyright @copyright{} 2019 Pierre Neidhardt@*
+
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.  A
+copy of the license is included in the section entitled ``GNU Free
+Documentation License''.
+@end copying
+
+@dircategory System administration
+@direntry
+* Guix cookbook: (guix-cookbook).    Tutorials and examples for GNU Guix.
+@end direntry
+
+@titlepage
+@title GNU Guix Cookbook
+@subtitle Tutorials and examples for using the GNU Guix Functional Package 
Manager
+@author The GNU Guix Developers
+
+@page
+@vskip 0pt plus 1filll
+
+@insertcopying
+@end titlepage
+
+@contents
+
+@c *********************************************************************
+@node Top
+@top GNU Guix Cookbook
+
+This document presents tutorials and detailed examples for GNU Guix, a
+functional package management tool written for the GNU system.  Please
+@pxref{Top,,, guix, GNU Guix reference manual} for details about the system,
+its API, and related concepts.
+
+@c TRANSLATORS: You can replace the following paragraph with information on
+@c how to join your own translation team and how to report issues with the
+@c translation.
+If you would like to translate this document in your native language, consider
+joining the @uref{https://translationproject.org/domain/guix-cookbook.html,
+Translation Project}.
+
+@menu
+* Packaging::                   Packaging tutorials
+* System Configuration::        Customizing the GNU System
+
+* Acknowledgments::             Thanks!
+* GNU Free Documentation License::  The license of this document.
+* Concept Index::               Concepts.
+
+@detailmenu
+ --- The Detailed Node Listing ---
+
+Packaging
+
+* Packaging Tutorial::          Let's add a package to Guix!
+
+System Configuration
+
+* Customizing the Kernel::      Creating and using a custom Linux kernel
+
+
+@end detailmenu
+@end menu
+
+@c *********************************************************************
+@node Packaging
+@chapter Packaging
+
+@cindex packaging
+
+This chapter is dedicated to teaching you how to add packages to the
+collection of packages that come with GNU Guix.  This involves writing package
+definitions in Guile Scheme, organizing them in package modules, and building
+them.
+
+@menu
+* Packaging Tutorial::         A tutorial on how to add packages to Guix.
+@end menu
+
+@node Packaging Tutorial
+@section Packaging Tutorial
+
+GNU Guix stands out as the @emph{hackable} package manager, mostly because it
+uses @uref{https://www.gnu.org/software/guile/, GNU Guile}, a powerful
+high-level programming language, one of the
+@uref{https://en.wikipedia.org/wiki/Scheme_(programming_language), Scheme}
+dialects from the
+@uref{https://en.wikipedia.org/wiki/Lisp_(programming_language), Lisp family}.
+
+Package definitions are also written in Scheme, which empowers Guix in some
+very unique ways, unlike most other package managers that use shell scripts or
+simple languages.
+
+@itemize
+@item
+Use functions, structures, macros and all of Scheme expressiveness for your
+package definitions.
+
+@item
+Inheritance makes it easy to customize a package by inheriting from it and
+modifying only what is needed.
+ 
+@item
+Batch processing: the whole package collection can be parsed, filtered and
+processed.  Building a headless server with all graphical interfaces stripped
+out?  It's possible.  Want to rebuild everything from source using specific
+compiler optimization flags?  Pass the @code{#:make-flags "..."} argument to
+the list of packages.  It wouldn't be a stretch to think
+@uref{https://wiki.gentoo.org/wiki/USE_flag, Gentoo USE flags} here, but this
+goes even further: the changes don't have to be thought out beforehand by the
+packager, they can be @emph{programmed} by the user!
+@end itemize
+
+The following tutorial covers all the basics around package creation with Guix.
+It does not assume much knowledge of the Guix system nor of the Lisp language.
+The reader is only expected to be familiar with the command line and to have 
some
+basic programming knowledge.
+
+@subsection A "Hello World" package
+
+The “Defining Packages” section of the manual introduces the basics of Guix
+packaging (@pxref{Defining Packages,,, guix, GNU Guix Reference Manual}).  In
+the following section, we will partly go over those basics again.
+
+``GNU hello'' is a dummy project that serves as an idiomatic example for
+packaging.  It uses the GNU build system (@code{./configure && make && make
+install}).  Guix already provides a package definition which is a perfect
+example to start with.  You can look up its declaration with @code{guix edit
+hello} from the command line.  Let's see how it looks:
+
+@example scheme
+(define-public hello
+  (package
+    (name "hello")
+    (version "2.10")
+    (source (origin
+              (method url-fetch)
+              (uri (string-append "mirror://gnu/hello/hello-" version
+                                  ".tar.gz"))
+              (sha256
+               (base32
+                "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
+    (build-system gnu-build-system)
+    (synopsis "Hello, GNU world: An example GNU package")
+    (description
+     "GNU Hello prints the message \"Hello, world!\" and then exits.  It
+serves as an example of standard GNU coding practices.  As such, it supports
+command-line arguments, multiple languages, and so on.")
+    (home-page "https://www.gnu.org/software/hello/";)
+    (license gpl3+)))
+@end example
+
+As you can see, most of it is rather straightforward.  But let's review the
+fields together:
+
+@table @samp
+@item name
+The project name.  Using Scheme conventions, we prefer to keep it
+lower case, without underscore and using dash-separated words.
+
+@item source
+This field contains a description of the source code origin.  The
+@code{origin} record contains these fields:
+
+@enumerate
+@item  The method, here @code{url-fetch} to download via HTTP/FTP, but other 
methods
+    exist, such as @code{git-fetch} for Git repositories.
+@item  The URI, which is typically some @code{https://} location for 
@code{url-fetch}.  Here
+    the special `mirror://gnu` refers to a set of well known locations, all of
+    which can be used by Guix to fetch the source, should some of them fail.
+@item  The @code{sha256} checksum of the requested file.  This is essential to 
ensure
+    the source is not corrupted.  Note that Guix works with base32 strings,
+    hence the call to the @code{base32} function.
+@end enumerate
+
+@item build-system
+
+This is where the power of abstraction provided by the Scheme language really
+shines: in this case, the @code{gnu-build-system} abstracts away the famous
+@code{./configure && make && make install} shell invocations.  Other build
+systems include the @code{trivial-build-system} which does not do anything and
+requires from the packager to program all the build steps, the
+@code{python-build-system}, the @code{emacs-build-system}, and many more
+(@pxref{Build Systems,,, guix, GNU Guix Reference Manual}).
+
+@item synopsis
+It should be a concise summary of what the package does.  For many packages a
+tagline from the project's home page can be used as the synopsis.
+    
+@item description
+Same as for the synopsis, it's fine to re-use the project description from the
+homepage.  Note that Guix uses Texinfo syntax.
+
+@item home-page
+Use HTTPS if available.
+
+@item license
+See @code{guix/licenses.scm} in the project source for a full list of
+available licenses.
+@end table
+
+Time to build our first package!  Nothing fancy here for now: we will stick to 
a
+dummy "my-hello", a copy of the above declaration.
+
+As with the ritualistic "Hello World" taught with most programming languages,
+this will possibly be the most "manual" approach.  We will work out an ideal
+setup later; for now we will go the simplest route.
+
+Save the following to a file @file{my-hello.scm}.
+
+@example scheme
+(use-modules (guix packages)
+             (guix download)
+             (guix build-system gnu)
+             (guix licenses))
+
+(package
+  (name "my-hello")
+  (version "2.10")
+  (source (origin
+            (method url-fetch)
+            (uri (string-append "mirror://gnu/hello/hello-" version
+                                ".tar.gz"))
+            (sha256
+             (base32
+              "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i"))))
+  (build-system gnu-build-system)
+  (synopsis "Hello, Guix world: An example custom Guix package")
+  (description
+   "GNU Hello prints the message \"Hello, world!\" and then exits.  It
+serves as an example of standard GNU coding practices.  As such, it supports
+command-line arguments, multiple languages, and so on.")
+  (home-page "https://www.gnu.org/software/hello/";)
+  (license gpl3+))
+@end example
+
+We will explain the extra code in a moment.
+
+Feel free to play with the different values of the various fields.  If you
+change the source, you'll need to update the checksum.  Indeed, Guix refuses to
+build anything if the given checksum does not match the computed checksum of 
the
+source code.  To obtain the correct checksum of the package declaration, we
+need to download the source, compute the sha256 checksum and convert it to
+base32.
+
+Thankfully, Guix can automate this task for us; all we need is to provide the
+URI:
+
+@c TRANSLATORS: This is example shell output.
+@example sh
+$ guix download mirror://gnu/hello/hello-2.10.tar.gz
+
+Starting download of /tmp/guix-file.JLYgL7
+From https://ftpmirror.gnu.org/gnu/hello/hello-2.10.tar.gz...
+following redirection to 
`https://mirror.ibcp.fr/pub/gnu/hello/hello-2.10.tar.gz'...
+ …10.tar.gz  709KiB                                 2.5MiB/s 00:00 
[##################] 100.0%
+/gnu/store/hbdalsf5lpf01x4dcknwx6xbn6n5km6k-hello-2.10.tar.gz
+0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i
+@end example
+
+In this specific case the output tells us which mirror was chosen.
+If the result of the above command is not the same as in the above snippet,
+update your @code{my-hello} declaration accordingly.
+
+Note that GNU package tarballs come with an OpenPGP signature, so you
+should definitely check the signature of this tarball with `gpg` to
+authenticate it before going further:
+
+@c TRANSLATORS: This is example shell output.
+@example sh
+$ guix download mirror://gnu/hello/hello-2.10.tar.gz.sig
+
+Starting download of /tmp/guix-file.03tFfb
+From https://ftpmirror.gnu.org/gnu/hello/hello-2.10.tar.gz.sig...
+following redirection to 
`https://ftp.igh.cnrs.fr/pub/gnu/hello/hello-2.10.tar.gz.sig'...
+ ….tar.gz.sig  819B                                                            
                                                           1.2MiB/s 00:00 
[##################] 100.0%
+/gnu/store/rzs8wba9ka7grrmgcpfyxvs58mly0sx6-hello-2.10.tar.gz.sig
+0q0v86n3y38z17rl146gdakw9xc4mcscpk8dscs412j22glrv9jf
+$ gpg --verify 
/gnu/store/rzs8wba9ka7grrmgcpfyxvs58mly0sx6-hello-2.10.tar.gz.sig 
/gnu/store/hbdalsf5lpf01x4dcknwx6xbn6n5km6k-hello-2.10.tar.gz
+gpg: Signature made Sun 16 Nov 2014 01:08:37 PM CET
+gpg:                using RSA key A9553245FDE9B739
+gpg: Good signature from "Sami Kerola <kerolasa@@iki.fi>" [unknown]
+gpg:                 aka "Sami Kerola (http://www.iki.fi/kerolasa/) 
<kerolasa@@iki.fi>" [unknown]
+gpg: WARNING: This key is not certified with a trusted signature!
+gpg:          There is no indication that the signature belongs to the owner.
+Primary key fingerprint: 8ED3 96E3 7E38 D471 A005  30D3 A955 3245 FDE9 B739
+@end example
+
+You can then happily run
+
+@c TRANSLATORS: Do not translate this command
+@example sh
+$ guix package --install-from-file=my-hello.scm
+@end example
+
+You should now have @code{my-hello} in your profile!
+
+@c TRANSLATORS: Do not translate this command
+@example sh
+$ guix package --list-installed=my-hello
+my-hello       2.10    out
+/gnu/store/f1db2mfm8syb8qvc357c53slbvf1g9m9-my-hello-2.10
+@end example
+
+We've gone as far as we could without any knowledge of Scheme.  Now is the 
right
+time to introduce the minimum we need from the language before we can proceed.
+
+
+@subsection A Scheme crash course
+
+@cindex Scheme, crash course
+As we've seen above, basic packages don't require much Scheme knowledge, if at
+all.  But as you progress and your desire to write more and more complex
+packages grows, it will become both necessary and empowering to hone your
+Lisper skills.
+
+Since an extensive Lisp course is very much out of the scope of this tutorial,
+we will only cover some basics here.
+
+Guix uses the Guile implementation of Scheme.  To start playing with the
+language, install it with @code{guix install guile} and start a
+@uref{https://en.wikipedia.org/wiki/Read%E2%80%93eval%E2%80%93print_loop,
+REPL} by running @code{guile} from the command line.
+
+Alternatively you can also run @code{guix environment --ad-hoc guile -- guile}
+if you'd rather not have Guile installed in your user profile.
+
+In the following examples we use the @code{>} symbol to denote the REPL
+prompt, that is, the line reserved for user input.  @xref{Using Guile
+Interactively,,, guile, GNU Guile Reference Manual}) for more details on the
+REPL.
+
+@itemize
+@item
+Scheme syntax boils down to a tree of expressions (or @emph{s-expression} in
+Lisp lingo).  An expression can be a literal such as numbers and strings, or a
+compound which is a parenthesized list of compounds and literals.  @code{#t}
+and @code{#f} stand for the booleans "true" and "false", respectively.
+
+Examples of valid expressions:
+
+@example scheme
+> "Hello World!"
+"Hello World!"
+> 17
+17
+> (display (string-append "Hello " "Guix" "\n"))
+"Hello Guix!"
+@end example
+
+@item
+This last example is a function call embedded in another function call.  When
+a parenthesized expression is evaluated, the first term is the function and
+the rest are the arguments passed to the function.  Every function returns the
+last evaluated expression as value.
+
+@item
+Anonymous functions are declared with the @code{lambda} term:
+
+@example scheme
+> (lambda (x) (* x x))
+#<procedure 120e348 at <unknown port>:24:0 (x)>
+@end example
+
+The above lambda returns the square of its argument.  Since everything is an
+expression, the @code{lambda} expression returns an anonymous function, which
+can in turn be applied to an argument:
+
+@example scheme
+> ((lambda (x) (* x x)) 3)
+9
+@end example
+
+@item
+Anything can be assigned a global name with @code{define}:
+
+@example scheme
+> (define a 3)
+> (define square (lambda (x) (* x x)))
+> (square a)
+9
+@end example
+
+@item
+Procedures can be defined more concisely with the following syntax:
+
+@example scheme
+(define (square x) (* x x))
+@end example
+
+@item
+A list structure can be created with the @code{list} procedure:
+
+@example scheme
+> (list 2 a 5 7)
+(2 3 5 7)
+@end example
+
+@item
+The @emph{quote} disables evaluation of a parenthesized expression: the first
+term is not called over the other terms.  Thus it effectively returns a list
+of terms.
+
+@example scheme
+> '(display (string-append "Hello " "Guix" "\n"))
+(display (string-append "Hello " "Guix" "\n"))
+> '(2 a 5 7)
+(2 a 5 7)
+@end example
+
+@item
+The @emph{quasiquote} disables evaluation of a parenthesized expression until
+a comma re-enables it.  Thus it provides us with fine-grained control over
+what is evaluated and what is not.
+
+@example scheme
+> `(2 a 5 7 (2 ,a 5 ,(+ a 4)))
+(2 a 5 7 (2 3 5 7))
+@end example
+
+Note that the above result is a list of mixed elements: numbers, symbols (here
+@code{a}) and the last element is a list itself.
+
+@item
+Multiple variables can be named locally with @code{let}:
+
+@example scheme
+> (define x 10)
+> (let ((x 2)
+        (y 3))
+    (list x y))
+(2 3)
+> x
+10
+> y
+ERROR: In procedure module-lookup: Unbound variable: y
+@end example
+
+Use @code{let*} to allow later variable declarations to refer to earlier
+definitions.
+
+@example scheme
+> (let* ((x 2)
+         (y (* x 3)))
+    (list x y))
+(2 6)
+@end example
+
+@item
+The keyword syntax is @code{#:}; it is used to create unique identifiers.
+@pxref{Keywords,,, guile, GNU Guile Reference Manual}.
+
+@item
+The percentage @code{%} is typically used for read-only global variables in
+the build stage.  Note that it is merely a convention, like @code{_} in C.
+Scheme treats @code{%} exactly the same as any other letter.
+
+@item
+Modules are created with @code{define-module}.  For instance
+
+@example scheme
+(define-module (guix build-system ruby)
+  #:use-module (guix store)
+  #:export (ruby-build
+            ruby-build-system))
+@end example
+
+defines the module @code{guix build-system ruby} which must be located in
+@file{guix/build-system/ruby.scm} somewhere in the Guile load path.  It
+depends on the @code{(guix store)} module and it exports two variables,
+@code{ruby-build} and @code{ruby-build-system}.
+@end itemize
+
+For a more detailed introduction, check out
+@uref{http://www.troubleshooters.com/codecorn/scheme_guile/hello.htm, Scheme
+at a Glance}, by Steve Litt.
+
+One of the reference Scheme books is the seminal ``Structure and
+Interpretation of Computer Programs'', by Harold Abelson and Gerald Jay
+Sussman, with Julie Sussman.  You'll find a
+@uref{https://mitpress.mit.edu/sites/default/files/sicp/index.html, free copy
+online}, together with
+@uref{https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-001-structure-and-interpretation-of-computer-programs-spring-2005/video-lectures/,
+videos of the lectures by the authors}.  The book is available in Texinfo
+format as the @code{sicp} Guix package.  Go ahead, run @code{guix install
+sicp} and start reading with @code{info sicp} (or with the Emacs Info reader).
+An @uref{https://sarabander.github.io/sicp/, unofficial ebook is also
+available}.
+
+You'll find more books, tutorials and other resources at
+@url{https://schemers.org/}.
+
+@c TODO: Continue the tutorial
+
+
+@c *********************************************************************
+@node System Configuration
+@chapter System Configuration
+
+Guix offers a flexible language for declaratively configuring your Guix
+System.  This flexibility can at times be overwhelming.  The purpose of this
+chapter is to demonstrate some advanced configuration concepts.
+
+@pxref{System Configuration,,, guix, GNU Guix Reference Manual} for a complete
+reference.
+
+@menu
+* Customizing the Kernel::     Creating and using a custom Linux kernel on 
Guix System.
+@end menu
+
+@node Customizing the Kernel
+@section Customizing the Kernel
+
+Guix is, at its core, a source based distribution with substitutes
+(@pxref{Substitutes,,, guix, GNU Guix Reference Manual}), and as such building
+packages from their source code is an expected part of regular package
+installations and upgrades.  Given this starting point, it makes sense that
+efforts are made to reduce the amount of time spent compiling packages, and
+recent changes and upgrades to the building and distribution of substitutes
+continues to be a topic of discussion within Guix.
+
+One of the packages which I prefer to not build myself is the
+Linux-Libre kernel.  The kernel, while not requiring an overabundance of
+RAM to build, does take a very long time on my build machine (which my
+children argue is actually their Kodi computer), and I will often delay
+reconfiguring my laptop while I want for a substitute to be prepared by
+the official build farm.  The official kernel configuration, as is the
+case with many GNU/Linux distributions, errs on the side of
+inclusiveness, and this is really what causes the build to take such a
+long time when I build the package for myself.
+
+The Linux kernel, however, can also just be described as a package
+installed on my machine, and as such can be customized just like any
+other package.  The procedure is a little bit different, although this
+is primarily due to the nature of how the package definition is written.
+
+The @code{linux-libre} kernel package definition is actually a procedure which
+creates a package.
+
+@example scheme
+(define* (make-linux-libre version hash supported-systems
+                           #:key
+                           ;; A function that takes an arch and a variant.
+                           ;; See kernel-config for an example.
+                           (extra-version #f)
+                           (configuration-file #f)
+                           (defconfig "defconfig")
+                           (extra-options %default-extra-linux-options)
+                           (patches (list %boot-logo-patch)))
+  ...)
+@end example
+
+The current @code{linux-libre} package is for the 5.1.x series, and is
+declared like this:
+
+@example scheme
+(define-public linux-libre
+  (make-linux-libre %linux-libre-version
+                    %linux-libre-hash
+                    '("x86_64-linux" "i686-linux" "armhf-linux" 
"aarch64-linux")
+                    #:patches %linux-libre-5.1-patches
+                    #:configuration-file kernel-config))
+@end example
+
+Any keys which are not assigned values inherit their default value from the
+@code{make-linux-libre} definition.  When comparing the two snippets above,
+you may notice that the code comment in the first doesn't actually refer to
+the @code{#:extra-version} keyword; it is actually for
+@code{#:configuration-file}.  Because of this, it is not actually easy to
+include a custom kernel configuration from the definition, but don't worry,
+there are other ways to work with what we do have.
+
+There are two ways to create a kernel with a custom kernel configuration.  The
+first is to provide a standard @file{.config} file during the build process by
+including an actual @file{.config} file as a native input to our custom
+kernel.  The following is a snippet from the custom @code{'configure} phase of
+the @code{make-linux-libre} package definition:
+
+@example scheme
+(let ((build  (assoc-ref %standard-phases 'build))
+      (config (assoc-ref (or native-inputs inputs) "kconfig")))
+
+  ;; Use a custom kernel configuration file or a default
+  ;; configuration file.
+  (if config
+      (begin
+        (copy-file config ".config")
+        (chmod ".config" #o666))
+      (invoke "make" ,defconfig))
+@end example
+
+Below is a sample kernel package for one of my computers.  Linux-Libre
+is just like other regular packages and can be inherited and overridden
+like any other:
+
+@example scheme
+(define-public linux-libre/E2140
+  (package
+    (inherit linux-libre)
+    (native-inputs
+     `(("kconfig" ,(local-file "E2140.config"))
+      ,@@(alist-delete "kconfig"
+                      (package-native-inputs linux-libre))))))
+@end example
+
+In the same directory as the file defining @code{linux-libre-E2140} is a file
+named @file{E2140.config}, which is an actual kernel configuration file.  I
+left the @code{defconfig} keyword of @code{make-linux-libre} blank, so the
+only kernel configuration in the package is the one which I included as a
+native-input.
+
+The second way to create a custom kernel is to pass a new value to the
+extra-options keyword of the @code{make-linux-libre} procedure.  The
+extra-options keyword works with another function defined right below it:
+
+@example scheme
+(define %default-extra-linux-options
+  `(;; https://lists.gnu.org/archive/html/guix-devel/2014-04/msg00039.html
+   ("CONFIG_DEVPTS_MULTIPLE_INSTANCES" . #t)
+   ;; Modules required for initrd:
+   ("CONFIG_NET_9P" . m)
+   ("CONFIG_NET_9P_VIRTIO" . m)
+   ("CONFIG_VIRTIO_BLK" . m)
+   ("CONFIG_VIRTIO_NET" . m)
+   ("CONFIG_VIRTIO_PCI" . m)
+   ("CONFIG_VIRTIO_BALLOON" . m)
+   ("CONFIG_VIRTIO_MMIO" . m)
+   ("CONFIG_FUSE_FS" . m)
+   ("CONFIG_CIFS" . m)
+   ("CONFIG_9P_FS" . m)))
+
+(define (config->string options)
+  (string-join (map (match-lambda
+                      ((option . 'm)
+                       (string-append option "=m"))
+                      ((option . #t)
+                       (string-append option "=y"))
+                      ((option . #f)
+                       (string-append option "=n")))
+                    options)
+               "\n"))
+@end example
+
+And in the custom configure script from the `make-linux-libre` package:
+
+@example scheme
+;; Appending works even when the option wasn't in the
+;; file.  The last one prevails if duplicated.
+(let ((port (open-file ".config" "a"))
+      (extra-configuration ,(config->string extra-options)))
+  (display extra-configuration port)
+  (close-port port))
+
+(invoke "make" "oldconfig"))))
+@end example
+
+So by not providing a configuration-file the @file{.config} starts blank, and
+then we write into it the collection of flags that we want.  Here's
+another custom kernel which I have:
+
+@example scheme
+(define %macbook41-full-config
+  (append %macbook41-config-options
+          %filesystems
+          %efi-support
+          %emulation
+          (@@@@ (gnu packages linux) %default-extra-linux-options)))
+
+(define-public linux-libre-macbook41
+  ;; XXX: Access the internal 'make-linux-libre' procedure, which is
+  ;; private and unexported, and is liable to change in the future.
+  ((@@@@ (gnu packages linux) make-linux-libre) (@@@@ (gnu packages linux) 
%linux-libre-version)
+                      (@@@@ (gnu packages linux) %linux-libre-hash)
+                      '("x86_64-linux")
+                      #:extra-version "macbook41"
+                      #:patches (@@@@ (gnu packages linux) 
%linux-libre-5.1-patches)
+                      #:extra-options %macbook41-config-options))
+@end example
+
+From the above example @code{%filesystems} is a collection of flags I compiled
+enabling different filesystem support, @code{%efi-support} enables EFI support
+and @code{%emulation} enables my x86_64-linux machine to act in 32-bit mode
+also. @code{%default-extra-linux-options} are the ones quoted above, which had
+to be added in since I replaced them in the extra-options keyword.
+
+This all sounds like it should be doable, but how does one even know which
+modules are required for their system?  The two places I found most helpful to
+try to answer this question were the
+@uref{https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/Kernel, Gentoo
+Handbook}, and the
+@uref{https://www.kernel.org/doc/html/latest/admin-guide/README.html?highlight=localmodconfig,
+documentation from the kernel itself}.  From the kernel documentation, it
+seems that @code{make localmodconfig} is the command we want.
+
+In order to actually run @code{make localmodconfig} we first need to get and
+unpack the kernel source code:
+
+@example shell
+tar xf $(guix build linux-libre --source)
+@end example
+
+Once inside the directory containing the source code run @code{touch .config}
+to create an initial, empty @file{.config} to start with.  @code{make
+localmodconfig} works by seeing what you already have in @file{.config} and
+letting you know what you're missing.  If the file is blank then you're
+missing everything.  The next step is to run:
+
+@example shell
+guix environment linux-libre -- make localmodconfig
+@end example
+
+and note the output.  Do note that the @file{.config} file is still empty.
+The output generally contains two types of warnings.  The first start with
+"WARNING" and can actually be ignored in our case.  The second read:
+
+@example shell
+module pcspkr did not have configs CONFIG_INPUT_PCSPKR
+@end example
+
+For each of these lines, copy the @code{CONFIG_XXXX_XXXX} portion into the
+@file{.config} in the directory, and append @code{=m}, so in the end it looks
+like this:
+
+@example shell
+CONFIG_INPUT_PCSPKR=m
+CONFIG_VIRTIO=m
+@end example
+
+After copying all the configuration options, run @code{make localmodconfig}
+again to make sure that you don't have any output starting with "module".
+After all of these machine specific modules there are a couple more left that
+are also needed.  @code{CONFIG_MODULES} is necessary so that you can build and
+load modules separately and not have everything built into the kernel.
+@code{CONFIG_BLK_DEV_SD} is required for reading from hard drives.  It is
+possible that there are other modules which you will need.
+
+This post does not aim to be a guide to configuring your own kernel
+however, so if you do decide to build a custom kernel you'll have to
+seek out other guides to create a kernel which is just right for your
+needs.
+
+The second way to setup the kernel configuration makes more use of
+Guix's features and allows you to share configuration segments between
+different kernels.  For example, all machines using EFI to boot have a
+number of EFI configuration flags that they need.  It is likely that all
+the kernels will share a list of filesystems to support.  By using
+variables it is easier to see at a glance what features are enabled and
+to make sure you don't have features in one kernel but missing in another.
+
+Left undiscussed however, is Guix's initrd and its customization.  It is
+likely that you'll need to modify the initrd on a machine using a custom
+kernel, since certain modules which are expected to be built may not be
+available for inclusion into the initrd.
+
+@c *********************************************************************
+@node Acknowledgments
+@chapter Acknowledgments
+
+Guix is based on the @uref{https://nixos.org/nix/, Nix package manager},
+which was designed and
+implemented by Eelco Dolstra, with contributions from other people (see
+the @file{nix/AUTHORS} file in Guix.)  Nix pioneered functional package
+management, and promoted unprecedented features, such as transactional
+package upgrades and rollbacks, per-user profiles, and referentially
+transparent build processes.  Without this work, Guix would not exist.
+
+The Nix-based software distributions, Nixpkgs and NixOS, have also been
+an inspiration for Guix.
+
+GNU@tie{}Guix itself is a collective work with contributions from a
+number of people.  See the @file{AUTHORS} file in Guix for more
+information on these fine people.  The @file{THANKS} file lists people
+who have helped by reporting bugs, taking care of the infrastructure,
+providing artwork and themes, making suggestions, and more---thank you!
+
+
+@c *********************************************************************
+@node GNU Free Documentation License
+@appendix GNU Free Documentation License
+@cindex license, GNU Free Documentation License
+@include fdl-1.3.texi
+
+@c *********************************************************************
+@node Concept Index
+@unnumbered Concept Index
+@printindex cp
+
+@bye
+
+@c Local Variables:
+@c ispell-local-dictionary: "american";
+@c End:
diff --git a/doc/local.mk b/doc/local.mk
index 336e961c4f..b37ab667ff 100644
--- a/doc/local.mk
+++ b/doc/local.mk
@@ -26,7 +26,13 @@ info_TEXINFOS = %D%/guix.texi                        \
   %D%/guix.es.texi                             \
   %D%/guix.fr.texi                             \
   %D%/guix.ru.texi                             \
-  %D%/guix.zh_CN.texi
+  %D%/guix.zh_CN.texi                          \
+  %D%/guix-cookbook.texi                       \
+  %D%/guix-cookbook.de.texi                    \
+  %D%/guix-cookbook.es.texi                    \
+  %D%/guix-cookbook.fr.texi                    \
+  %D%/guix-cookbook.ru.texi                    \
+  %D%/guix-cookbook.zh_CN.texi
 
 %C%_guix_TEXINFOS = \
   %D%/contributing.texi \
@@ -63,6 +69,11 @@ TRANSLATED_INFO =                            \
   %D%/guix.fr.texi                             \
   %D%/guix.ru.texi                             \
   %D%/guix.zh_CN.texi                          \
+  %D%/guix-cookbook.de.texi                    \
+  %D%/guix-cookbook.es.texi                    \
+  %D%/guix-cookbook.fr.texi                    \
+  %D%/guix-cookbook.ru.texi                    \
+  %D%/guix-cookbook.zh_CN.texi                 \
   %D%/contributing.de.texi                     \
   %D%/contributing.es.texi                     \
   %D%/contributing.fr.texi                     \
@@ -108,6 +119,12 @@ $(srcdir)/%D%/guix.%.texi: po/doc/guix-manual.%.po 
$(srcdir)/%D%/contributing.%.
        -$(AM_V_POXREF)$(xref_command)
        -mv "$@.tmp" "$@"
 
+$(srcdir)/%D%/guix-cookbook.%.texi: po/doc/guix-cookbook.%.po
+       -$(AM_V_PO4A)$(PO4A_TRANSLATE) $(PO4A_PARAMS) -m 
"%D%/guix-cookbook.texi" -p "$<" -l "$@.tmp"
+       -sed -i "s|guix-cookbook\.info|$$(basename "$@" | sed 
's|texi$$|info|')|" "$@.tmp"
+       -$(AM_V_POXREF)$(xref_command)
+       -mv "$@.tmp" "$@"
+
 $(srcdir)/%D%/contributing.%.texi: po/doc/guix-manual.%.po
        -$(AM_V_PO4A)$(PO4A_TRANSLATE) $(PO4A_PARAMS) -m 
"%D%/contributing.texi" -p "$<" -l "$@.tmp"
        -$(AM_V_POXREF)$(xref_command)
diff --git a/po/doc/local.mk b/po/doc/local.mk
index fb3c5aee03..4b70e1dc96 100644
--- a/po/doc/local.mk
+++ b/po/doc/local.mk
@@ -23,9 +23,18 @@ DOC_PO_FILES=                                        \
   %D%/guix-manual.ru.po                                \
   %D%/guix-manual.zh_CN.po
 
+DOC_COOKBOOK_PO_FILES=                         \
+  %D%/guix-cookbook.es.po                      \
+  %D%/guix-cookbook.de.po                      \
+  %D%/guix-cookbook.fr.po                      \
+  %D%/guix-cookbook.ru.po                      \
+  %D%/guix-cookbook.zh_CN.po
+
 EXTRA_DIST = \
   %D%/guix-manual.pot \
-  $(DOC_PO_FILES)
+  %D%/guix-cookbook.pot \
+  $(DOC_PO_FILES) \
+  $(DOC_COOKBOOK_PO_FILES)
 
 POT_OPTIONS = --package-name "guix" --package-version "$(VERSION)" \
                  --copyright-holder "Ludovic Courtès" \
@@ -52,6 +61,27 @@ doc-po-update-%:
             exit 1; \
        fi
 
+doc-po-update-cookbook-%:
+       @lang=`echo "$@" | sed -e's/^doc-po-update-//'` ; \
+       output="$(srcdir)/po/doc/guix-cookbook.$$lang.po" ; \
+       input="$(srcdir)/po/doc/guix-cookbook.pot" ; \
+       if test -f "$$output"; then \
+         test "$(srcdir)" = . && cdcmd="" || cdcmd="cd $(srcdir) && "; \
+         echo "$${cdcmd}$(MSGMERGE_UPDATE) $(MSGMERGE_OPTIONS) --lang=$${lang} 
$$output $$input"; \
+         cd $(srcdir) \
+           && { case `$(MSGMERGE_UPDATE) --version | sed 1q | sed -e 
's,^[^0-9]*,,'` in \
+               '' | 0.[0-9] | 0.[0-9].* | 0.1[0-7] | 0.1[0-7].*) \
+                 $(MSGMERGE_UPDATE) $(MSGMERGE_OPTIONS) "$$output" "$$input";; 
\
+               *) \
+                 $(MSGMERGE_UPDATE) $(MSGMERGE_OPTIONS) --lang=$${lang} 
"$$output" "$$input";; \
+             esac; \
+           }; \
+         touch "$$output"; \
+       else \
+            echo "File $$output does not exist.  If you are a translator, you 
can create it with 'msginit'." 1>&2; \
+            exit 1; \
+       fi
+
 $(srcdir)/po/doc/%.pot-update: doc/%.texi
        $(AM_V_PO4A)$(PO4A_UPDATEPO) -M UTF-8 -f texinfo -m "$<" \
                -p "$$(echo $@ | sed 's|-update||')" $(POT_OPTIONS)
@@ -64,6 +94,7 @@ doc-pot-update:
                $(MAKE) $(srcdir)/po/doc/guix.pot-update; \
                $(MAKE) $(srcdir)/po/doc/contributing.pot-update; \
        done
+       $(MAKE) $(srcdir)/po/doc/guix-cookbook.pot-update;
        msgcat $(addprefix $(srcdir)/po/doc/, $(TMP_POT_FILES)) > 
$(srcdir)/po/doc/guix-manual.pot
        rm -f $(addprefix $(srcdir)/po/doc/, $(TMP_POT_FILES))
 
@@ -72,5 +103,10 @@ doc-po-update: doc-pot-update
          lang="`echo "$$f" | $(SED) -es'|.*/guix-manual\.\(.*\)\.po$$|\1|g'`"; 
\
          $(MAKE) "doc-po-update-$$lang";                                       
\
        done
+       for f in $(DOC_COOKBOOK_PO_FILES); do                                   
        \
+         lang="`echo "$$f" | $(SED) 
-es'|.*/guix-cookbook\.\(.*\)\.po$$|\1|g'`";       \
+         $(MAKE) "doc-po-update-cookbook-$$lang";                              
                \
+       done
+
 
 .PHONY: doc-po-update doc-pot-update
-- 
2.22.0