[bug#46031] services: cuirass: Add "simple-cuirass-services".

[Mathieu Othacehe]

Hey,

> I guess the first step would be to provide an a ‘package-channel(s)’
> procedure that does like ‘package-provenance’, but returns a list of
> channels.

Seems fine to me. Here's an implementation attached. If it works for
you, the next step will be to make the "cuirass-jobs" procedure of
"gnu-system.scm" operate on channels I guess.

WDYT?

Thanks,

Mathieu

>From d44dcd5d153ba0a4627c205f24a0741384f3d301 Mon Sep 17 00:00:00 2001
From: Mathieu Othacehe <othacehe@gnu.org>
Date: Tue, 23 Feb 2021 14:24:39 +0100
Subject: [PATCH] describe: Add package-channels.

* guix/describe.scm (package-channels): New procedure.
---
 guix/describe.scm | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/guix/describe.scm b/guix/describe.scm
index 03569b1db4..65e5772856 100644
--- a/guix/describe.scm
+++ b/guix/describe.scm
@@ -33,6 +33,7 @@
             package-path-entries
 
             package-provenance
+            package-channels
             manifest-entry-with-provenance
             manifest-entry-provenance))
 
@@ -178,6 +179,26 @@ property of manifest entries, or #f if it could not be 
determined."
                        `(,main
                          ,@(if extra (list extra) '()))))))))))
 
+(define (package-channels package)
+  "Return the list of channels providing PACKAGE or an empty list if it could
+not be determined."
+  (match (and=> (package-location package) location-file)
+    (#f #f)
+    (file
+     (let ((file (if (string-prefix? "/" file)
+                     file
+                     (search-path %load-path file))))
+       (and file
+            (string-prefix? (%store-prefix) file)
+
+            (filter-map
+             (lambda (entry)
+               (let ((item (manifest-entry-item entry)))
+                 (and (or (string-prefix? item file)
+                          (string=? "guix" (manifest-entry-name entry)))
+                      (manifest-entry-channel entry))))
+             (current-profile-entries)))))))
+
 (define (manifest-entry-with-provenance entry)
   "Return ENTRY with an additional 'provenance' property if it's not already
 there."
-- 
2.30.1