services: guix-data-service: Allow passing extra options.

This is so that the options supported by the service configuration don't have
to always be changed. Generally though all options should be explicitly
supported and documented, so this is mostly to facilitate experimentation.

* gnu/services/guix.scm (<guix-data-service-configuration>): Add extra-options
and extra-process-jobs-options to the record type.
(guix-data-service-shepherd-services): Handle these new configuration record
fields.
* doc/guix.texi (Guix Data Service): Document these new options.

doc/guix.texi

@@ -25250,6 +25250,12 @@ If set, this is the @code{getmail-retriever-configuration} object with
 which to configure getmail to fetch mail from the guix-commits mailing
 list.
 
+@item @code{extra-options} (default: @var{'()})
+Extra command line options for @code{guix-data-service}.
+
+@item @code{extra-process-jobs-options} (default: @var{'()})
+Extra command line options for @code{guix-data-service-process-jobs}.
+
 @end table
 @end deftp
 

gnu/services/guix.scm

@@ -68,7 +68,12 @@
    (default #f))
   (commits-getmail-retriever-configuration
    guix-data-service-commits-getmail-retriever-configuration
-   (default #f)))
+   (default #f))
+  (extra-options    guix-data-service-extra-options
+                    (default '()))
+  (extra-process-jobs-options
+   guix-data-service-extra-process-jobs-options
+   (default '())))
 
 (define (guix-data-service-profile-packages config)
   "Return the guix-data-service package, this will populate the
@@ -78,7 +83,7 @@ ca-certificates.crt file in the system profile."
 
 (define (guix-data-service-shepherd-services config)
   (match-record config <guix-data-service-configuration>
-    (package user group port host)
+    (package user group port host extra-options extra-process-jobs-options)
     (list
      (shepherd-service
       (documentation "Guix Data Service web server")
@@ -92,7 +97,8 @@ ca-certificates.crt file in the system profile."
                       #$(string-append "--host=" host)
                       ;; Perform any database migrations when the
                       ;; service is started
-                      "--update-database")
+                      "--update-database"
+                      #$@extra-options)
 
                 #:user #$user
                 #:group #$group
@@ -117,7 +123,8 @@ ca-certificates.crt file in the system profile."
       (start #~(make-forkexec-constructor
                 (list
                  #$(file-append package
-                                "/bin/guix-data-service-process-jobs"))
+                                "/bin/guix-data-service-process-jobs")
+                 #$@extra-process-jobs-options)
                 #:user #$user
                 #:group #$group
                 #:environment-variables