Package: guix-patches;
Reported by: Brice Waegeneire <brice <at> waegenei.re>
Date: Sat, 17 Jul 2021 20:59:01 UTC
Severity: normal
Tags: patch
Done: Ludovic Courtès <ludo <at> gnu.org>
Bug is archived. No further changes may be made.
Message #26 received at 49610 <at> debbugs.gnu.org (full text, mbox):
From: Brice Waegeneire <brice <at> waegenei.re> To: ludo <at> gnu.org Cc: 49610 <at> debbugs.gnu.org Subject: [PATCH v2] sevices: guix: Add channels field. Date: Tue, 21 Dec 2021 22:00:42 +0100
* doc/guix.texi (Channels): Specify that '/etc/guix/channels.scm'
contains channels configuration.
(Base Services): Document 'guix-configuration-channels' field.
* gnu/services/base.scm (install-channels-file): New procedure.
(guix-configuration): Add channels field.
(guix-activation): Use 'install-channels-file' procedure.
---
doc/guix.texi | 15 ++++++++++++++-
gnu/services/base.scm | 42 ++++++++++++++++++++++++++++++++++++++++--
2 files changed, 54 insertions(+), 3 deletions(-)
I've changed the type of the new field from a list to a s-expression, I'm not
sure if it should be a G-exp instead. The documentation of the
'channels' field as been updated as suggested.
Ludovic Courtès <ludo <at> gnu.org> writes:
>> +;; FIXME Does this gexp should be build before boot, such as
>> +;; substitute-key-authorization does?
>
> There’s a grammatical issue :-), but also I’m not sure: what are you
> worried about?
This is related to your commit 8b3ad455be7e8ace35a2eaebf7fffbb611280852, where
you added pre-computation of the ACL to make « [...] the first boot slightly
faster ». Should this be done in this case too?
>> + (channels guix-configuration-channels ;list of channels
>> + (default '()))
>
> I wonder if it should default to ‘%default-channels’, for consistency
> and least-surprise. In practice, it means we’d always end up creating
> /etc/guix/channels.scm, but that’s probably OK. (The downside is if we,
> Guix devs, choose to change ‘%default-channels’ at some point: users
> would be stuck with the value that got written to /etc. That’s a very
> hypothetical situation though.)
Users would not have been stuck with a stale ‘%default-channels’, even with
the first version of this patch. The issue with using a non null default
value, is the absence of backward compatibility. A user with an already defined
/etc/guix/chanels.scm, would see its custom channels being replaced by the
default one after having reconfigure a system with this patch for the first
time. So I guess I should make further adjustment to the patch
¹ <https://git.savannah.gnu.org/cgit/guix.git/commit/?id=8b3ad455be7e8ace35a2eaebf7fffbb611280852>
diff --git a/doc/guix.texi b/doc/guix.texi
index a826171f34..5284a69156 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -5001,7 +5001,7 @@ $ wget -O - \
Guix and its package collection are updated by running @command{guix pull}
(@pxref{Invoking guix pull}). By default @command{guix pull} downloads and
deploys Guix itself from the official GNU <at> tie{}Guix repository. This can be
-customized by defining @dfn{channels} in the
+customized by defining @dfn{channels} in @file{/etc/guix/channels.scm} and
@file{~/.config/guix/channels.scm} file. A channel specifies a URL and branch
of a Git repository to be deployed, and @command{guix pull} can be instructed
to pull from one or more channels. In other words, channels can be used
@@ -15557,6 +15557,19 @@ This example assumes that the file @file{./guix.example.org-key.pub}
contains the public key that @code{guix.example.org} uses to sign
substitutes.
+@item @code{channels} (default: @code{'(cons* %default-channels)})
+S-expression producing a list of channels to be used by @command{guix
+pull}, by default. The S-exp is written to
+@file{/etc/guix/channels.scm}.
+
+@quotation Note
+When booting or reconfiguring to a system where @code{channels}
+is not null, the existing @file{/etc/guix/channels.scm} file is backed up as
+@file{/etc/guix/channels.scm.bak} if it was determined to be a manually modified
+file. This is to facilitate migration from earlier versions, which
+allowed for in-place modifications to @file{/etc/guix/channels.scm}.
+@end quotation
+
@item @code{max-silent-time} (default: @code{0})
@itemx @code{timeout} (default: @code{0})
The number of seconds of silence and the number of seconds of activity,
diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index e206bea5f0..c9823e6d55 100644
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -58,6 +58,7 @@
#:use-module (gnu packages terminals)
#:use-module ((gnu build file-systems)
#:select (mount-flags->bit-mask))
+ #:use-module (guix channels)
#:use-module (guix gexp)
#:use-module (guix records)
#:use-module (guix modules)
@@ -66,6 +67,7 @@
#:use-module (srfi srfi-26)
#:use-module (ice-9 match)
#:use-module (ice-9 format)
+ #:use-module (ice-9 pretty-print)
#:re-export (user-processes-service-type ;backwards compatibility
%default-substitute-urls)
#:export (fstab-service-type
@@ -1502,6 +1504,39 @@ archive' public keys, with GUIX."
;; Installed the declared ACL.
(symlink #+default-acl "/etc/guix/acl"))))
+;; FIXME Does this gexp should be built before boot, such as
+;; substitute-key-authorization does?
+(define (install-channels-file channels)
+ "Return a gexp with code to install a file with CHANNELS, a S-exp returning
+a list of channels."
+ (define channels-file
+ (plain-file "channels.scm"
+ (with-output-to-string
+ (lambda _
+ (pretty-print (map (lambda (channel)
+ (if (channel? channel)
+ (channel->code channel)
+ channel))
+ channels))))))
+
+ (with-imported-modules '((guix build utils))
+ #~(begin
+ (use-modules (guix build utils))
+
+ ;; If channels.scm already exists, move it out of the way. Create a
+ ;; backup if it's a regular file: it's likely that the user
+ ;; manually defined it.
+ (if (file-exists? "/etc/guix/channels.scm")
+ (if (and (symbolic-link? "/etc/guix/channels.scm")
+ (store-file-name? (readlink "/etc/guix/channels.scm")))
+ (delete-file "/etc/guix/channels.scm")
+ (rename-file "/etc/guix/channels.scm"
+ "/etc/guix/channels.scm.bak"))
+ (mkdir-p "/etc/guix"))
+
+ ;; Installed the declared channels.
+ (symlink #+channels-file "/etc/guix/channels.scm"))))
+
(define %default-authorized-guix-keys
;; List of authorized substitute keys.
(list (file-append guix "/share/guix/berlin.guix.gnu.org.pub")
@@ -1524,6 +1559,8 @@ archive' public keys, with GUIX."
(default #t))
(substitute-urls guix-configuration-substitute-urls ;list of strings
(default %default-substitute-urls))
+ (channels guix-configuration-channels ;sexp
+ (default '(cons* %default-channels)))
(chroot-directories guix-configuration-chroot-directories ;list of file-like/strings
(default '()))
(max-silent-time guix-configuration-max-silent-time ;integer
@@ -1701,7 +1738,7 @@ proxy of 'guix-daemon'...~%")
(define (guix-activation config)
"Return the activation gexp for CONFIG."
(match-record config <guix-configuration>
- (guix authorize-key? authorized-keys)
+ (guix authorize-key? authorized-keys channels)
#~(begin
;; Assume that the store has BUILD-GROUP as its group. We could
;; otherwise call 'chown' here, but the problem is that on a COW overlayfs,
@@ -1714,7 +1751,8 @@ proxy of 'guix-daemon'...~%")
#$(if authorize-key?
(substitute-key-authorization authorized-keys guix)
- #~#f))))
+ #~#f)
+ #$(install-channels-file channels))))
(define* (references-file item #:optional (name "references"))
"Return a file that contains the list of references of ITEM."
--
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