[bug#54918,WIP] make guix-service-type more extendable

From 314f6f1c8cb1057e6880f1776d096a615c2c5a30 Mon Sep 17 00:00:00 2001
From: terramorpha <terramorpha@cock.li>
Date: Mon, 11 Apr 2022 00:30:07 -0400
Subject: [PATCH] commit message

---
 doc/guix.texi         | 21 ++++++++++++++++++
 gnu/services/base.scm | 50 ++++++++++++++++++++++++++++++++++---------
 2 files changed, 61 insertions(+), 10 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 54793c9648..910183a8d2 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -102,6 +102,7 @@  Copyright @copyright{} 2021 Sarah Morgensen@*
 Copyright @copyright{} 2021 Josselin Poiret@*
 Copyright @copyright{} 2022 Remco van 't Veer@*
 Copyright @copyright{} 2022 Aleksandr Vityazev@*
+Copyright @copyright{} 2022 Justin Veilleux@*
 
 Permission is granted to copy, distribute and/or modify this document
 under the terms of the GNU Free Documentation License, Version 1.3 or
@@ -17147,6 +17148,26 @@  A directory path where the @command{guix-daemon} will perform builds.
 @end table
 @end deftp
 
+@anchor{guix-extension-type}
+@deftp {Data Type} guix-extension
+
+This data type represents the parameters of the Guix build daemon that
+are extendable. This is the type of the object that must be used within
+a guix service extension.
+@xref{Service Composition}, for more information.
+
+@table @asis
+@item @code{authorized-keys} (default: @code{'()})
+A list of file-like objects where each element contains a public key.
+
+@item @code{substitute-urls} (default: @code{'()})
+A list of strings where each element is a substitute URL.
+
+@item @code{chroot-directories} (default: @code{'()})
+A list of file-like objects or strings pointing to additional directories the build daemon can use.
+@end table
+@end deftp
+
 @deffn {Scheme Procedure} udev-service [#:udev @var{eudev} #:rules @code{'()}]
 Run @var{udev}, which populates the @file{/dev} directory dynamically.
 udev rules can be provided as a list of files through the @var{rules}
diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index 5d7c69a9cd..fc799cb806 100644
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -17,6 +17,7 @@ 
 ;;; Copyright © 2021 Hui Lu <luhuins@163.com>
 ;;; Copyright © 2021, 2022 Maxim Cournoyer <maxim.cournoyer@gmail.com>
 ;;; Copyright © 2022 Guillaume Le Vaillant <glv@posteo.net>
+;;; Copyright © 2022 Justin Veilleux <terramorpha@cock.li>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -187,6 +188,12 @@  (define-module (gnu services base)
             guix-configuration-extra-options
             guix-configuration-log-file
 
+            guix-extension
+            guix-extension?
+            guix-extension-authorized-keys
+            guix-extension-substitute-urls
+            guix-extension-chroot-directories
+
             guix-service-type
             guix-publish-configuration
             guix-publish-configuration?
@@ -1788,6 +1795,25 @@  (define* (references-file item #:optional (name "references"))
                                  #:references-graphs (("graph" ,item))))
       (plain-file name "()")))
 
+(define-record-type* <guix-extension>
+  guix-extension make-guix-extension
+  guix-extension?
+  (authorized-keys guix-extension-authorized-keys ;list of file-like
+                    (default '()))
+  (substitute-urls guix-extension-substitute-urls ;list of strings
+                    (default '()))
+  (chroot-directories guix-extension-chroot-directories ;list of file-like/strings
+                      (default '())))
+
+(define (guix-extension-merge a b)
+  (guix-extension
+   (authorized-keys (append (guix-extension-authorized-keys a)
+                            (guix-extension-authorized-keys b)))
+   (substitute-urls (append (guix-extension-substitute-urls a)
+                            (guix-extension-substitute-urls b)))
+   (chroot-directories (append (guix-extension-chroot-directories a)
+                               (guix-extension-chroot-directories b)))))
+
 (define guix-service-type
   (service-type
    (name 'guix)
@@ -1798,30 +1824,34 @@  (define guix-service-type
           (service-extension profile-service-type
                              (compose list guix-configuration-guix))))
 
-   ;; Extensions can specify extra directories to add to the build chroot.
-   (compose concatenate)
-   (extend (lambda (config directories)
+   ;; Extensions can specify extra directories to add to the build chroot,
+   ;; extra substitute urls and extra authorized keys
+   (compose (lambda (args) (fold guix-extension-merge (guix-extension) args)))
+   (extend (lambda (config extension)
              (guix-configuration
               (inherit config)
+              (authorized-keys (append (guix-extension-authorized-keys extension)
+                                       (guix-configuration-authorized-keys config)))
+              (substitute-urls (append (guix-extension-substitute-urls extension)
+                                       (guix-configuration-substitute-urls config)))
               (chroot-directories
-               (append (guix-configuration-chroot-directories config)
-                       directories)))))
+               (append (guix-extension-chroot-directories extension)
+                       (guix-configuration-chroot-directories config))))))
 
    (default-value (guix-configuration))
    (description
     "Run the build daemon of GNU@tie{}Guix, aka. @command{guix-daemon}.")))
 
-
 (define-record-type* <guix-publish-configuration>
   guix-publish-configuration make-guix-publish-configuration
   guix-publish-configuration?
-  (guix    guix-publish-configuration-guix        ;file-like
+  (guix    guix-publish-configuration-guix ;file-like
            (default guix))
-  (port    guix-publish-configuration-port        ;number
+  (port    guix-publish-configuration-port ;number
            (default 80))
-  (host    guix-publish-configuration-host        ;string
+  (host    guix-publish-configuration-host ;string
            (default "localhost"))
-  (advertise? guix-publish-advertise?       ;boolean
+  (advertise? guix-publish-advertise?   ;boolean
               (default #f))
   (compression       guix-publish-configuration-compression
                      (thunked)
-- 
2.34.0