Revert "services: configuration: Revert to a working ‘guix home’."

This reverts commit 39e4e00f75be8055300cb0afffb8bd4b4d35f2cc, with fixes for
the guix home issues reported and another one found while reconfiguring berlin
in the subsequent commit.

3 files changed, 43 insertions, 18 deletions

diff --git a/gnu/services/configuration.scm b/gnu/services/configuration.scm
index 636c49ccba..dacfc52ba9 100644
--- a/gnu/services/configuration.scm
+++ b/gnu/services/configuration.scm
@@ -242,17 +242,17 @@ does not have a default value" field kind)))
                stem
                #,(id #'stem #'make- #'stem)
                #,(id #'stem #'stem #'?)
-               (%location #,(id #'stem #'stem #'-location)
-                          (default (and=> (current-source-location)
-                                          source-properties->location))
-                          (innate))
                #,@(map (lambda (name getter def)
                          #`(#,name #,getter (default #,def)
                                    (sanitize
                                     #,(id #'stem #'validate- #'stem #'- name))))
                        #'(field ...)
                        #'(field-getter ...)
-                       #'(field-default ...)))
+                       #'(field-default ...))
+               (%location #,(id #'stem #'stem #'-location)
+                          (default (and=> (current-source-location)
+                                          source-properties->location))
+                          (innate)))
 
              (define #,(id #'stem #'stem #'-fields)
                (list (configuration-field
diff --git a/gnu/services/mcron.scm b/gnu/services/mcron.scm
index 23760ebda4..52332d6123 100644
--- a/gnu/services/mcron.scm
+++ b/gnu/services/mcron.scm
@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2022 Maxim Cournoyer <maxim.cournoyer@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -18,6 +19,7 @@
 
 (define-module (gnu services mcron)
   #:use-module (gnu services)
+  #:use-module (gnu services configuration)
   #:use-module (gnu services shepherd)
   #:use-module (gnu packages guile-xyz)
   #:use-module (guix deprecation)
@@ -30,6 +32,8 @@
             mcron-configuration?
             mcron-configuration-mcron
             mcron-configuration-jobs
+            mcron-configuration-log?
+            mcron-configuration-log-format
 
             mcron-service-type))
 
@@ -48,13 +52,23 @@
 ;;;
 ;;; Code:
 
-(define-record-type* <mcron-configuration> mcron-configuration
-  make-mcron-configuration
-  mcron-configuration?
-  (mcron             mcron-configuration-mcron    ;file-like
-                     (default mcron))
-  (jobs              mcron-configuration-jobs     ;list of <mcron-job>
-                     (default '())))
+(define list-of-gexps?
+  (list-of gexp?))
+
+(define-configuration/no-serialization mcron-configuration
+  (mcron (file-like mcron) "The mcron package to use.")
+  (jobs
+   (list-of-gexps '())
+   "This is a list of gexps (@pxref{G-Expressions}), where each gexp
+corresponds to an mcron job specification (@pxref{Syntax, mcron job
+specifications,, mcron, GNU@tie{}mcron}).")
+  (log? (boolean #t) "Log messages to standard output.")
+  (log-format
+   (string "~1@*~a ~a: ~a~%")
+   "@code{(ice-9 format)} format string for log messages.  The default value
+produces messages like \"@samp{@var{pid} @var{name}:
+@var{message}\"} (@pxref{Invoking mcron, Invoking,, mcron, GNU@tie{}mcron}).
+Each message is also prefixed by a timestamp by GNU Shepherd."))
 
 (define (job-files mcron jobs)
   "Return a list of file-like object for JOBS, a list of gexps."
@@ -124,21 +138,25 @@ files."
 
 (define mcron-shepherd-services
   (match-lambda
-    (($ <mcron-configuration> mcron ())           ;nothing to do!
+    (($ <mcron-configuration> mcron ()) ;nothing to do!
      '())
-    (($ <mcron-configuration> mcron jobs)
+    (($ <mcron-configuration> mcron jobs log? log-format)
      (let ((files (job-files mcron jobs)))
        (list (shepherd-service
               (provision '(mcron))
               (requirement '(user-processes))
               (modules `((srfi srfi-1)
                          (srfi srfi-26)
-                         (ice-9 popen)            ;for the 'schedule' action
+                         (ice-9 popen)  ;for the 'schedule' action
                          (ice-9 rdelim)
                          (ice-9 match)
                          ,@%default-modules))
               (start #~(make-forkexec-constructor
-                        (list (string-append #$mcron "/bin/mcron") #$@files)
+                        (list (string-append #$mcron "/bin/mcron")
+                              #$@(if log?
+                                     #~("--log" "--log-format" #$log-format)
+                                     #~())
+                              #$@files)
 
                         ;; Disable auto-compilation of the job files and set a
                         ;; sane value for 'PATH'.
@@ -172,4 +190,11 @@ files."
                                          jobs)))))
                 (default-value (mcron-configuration)))) ;empty job list
 
+
+;;;
+;;; Generate documentation.
+;;;
+(define (generate-doc)
+  (configuration->documentation 'mcron-configuration))
+
 ;;; mcron.scm ends here
diff --git a/gnu/services/monitoring.scm b/gnu/services/monitoring.scm
index 9c8704092c..b19c6c9f18 100644
--- a/gnu/services/monitoring.scm
+++ b/gnu/services/monitoring.scm
@@ -622,8 +622,8 @@ create it manually.")
 
 (define (zabbix-front-end-config config)
   (match-record config <zabbix-front-end-configuration>
-    (%location db-host db-port db-name db-user db-password db-secret-file
-               zabbix-host zabbix-port)
+    (db-host db-port db-name db-user db-password db-secret-file
+             zabbix-host zabbix-port %location)
     (mixed-text-file "zabbix.conf.php"
                      "\
 <?php