home: services: Add dicod.

* gnu/home/services/dict.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
* gnu/services/dict.scm (<dicod-configuration>)[home-service?]: New
field.
(dicod-shepherd-service): Do not map /dev/log when 'home-service?' is
true.  Remove 'user-processes' requirement when 'home-service?' is
true.
(dicod-shepherd-service): Set #:user and #:group to #f when
'home-service?' is true.
* doc/guix.texi (Miscellaneous Home Services): New node.
(Miscellaneous Services): Add cross-reference.

4 files changed, 96 insertions, 9 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index efb4cec9ef..5463fb6998 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -450,6 +450,7 @@ Home Services
 * Mail: Mail Home Services.     Services for managing mail.
 * Messaging: Messaging Home Services.  Services for managing messaging.
 * Media: Media Home Services.   Services for managing media.
+* Miscellaneous: Miscellaneous Home Services.  More services.
 
 Platforms
 
@@ -39082,6 +39083,12 @@ implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
 You can add @command{open localhost} to your @file{~/.dico} file to make
 @code{localhost} the default server for @command{dico} client
 (@pxref{Initialization File,,, dico, GNU Dico Manual}).
+
+@quotation Note
+This service is also available for Guix Home, where it runs directly
+with your user privileges (@pxref{Miscellaneous Home Services,
+@code{home-dicod-service-type}}).
+@end quotation
 @end defvar
 
 @deftp {Data Type} dicod-configuration
@@ -42972,6 +42979,7 @@ services)}.
 * Mail: Mail Home Services.     Services for managing mail.
 * Messaging: Messaging Home Services.  Services for managing messaging.
 * Media: Media Home Services.   Services for managing media.
+* Miscellaneous: Miscellaneous Home Services.  More services.
 @end menu
 @c In addition to that Home Services can provide
 
@@ -44561,6 +44569,43 @@ kodi} for more information.
 @end table
 @end deftp
 
+@node Miscellaneous Home Services
+@subsection Miscellaneous Home Services
+
+This section lists Home services that lack a better place.
+
+@subsubheading Dictionary Service
+
+@cindex dictionary service, for Home
+The @code{(gnu home services dict)} module provides the following service:
+
+@defvar home-dicod-service-type
+This is the type of the service that runs the @command{dicod} daemon, an
+implementation of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
+
+You can add @command{open localhost} to your @file{~/.dico} file to make
+@code{localhost} the default server for @command{dico} client
+(@pxref{Initialization File,,, dico, GNU Dico Manual}).
+@end defvar
+
+This service is a direct mapping of the @code{dicod-service-type} system
+service (@pxref{Miscellaneous Services, Dictionary Service}).  You can
+use it like this:
+
+@lisp
+(service home-dicod-service-type)
+@end lisp
+
+You may specify a custom configuration by providing a
+@code{dicod-configuration} record, exactly like for
+@code{dicod-service-type}, but wrapping it in @code{for-home}:
+
+@lisp
+(service home-dicod-service-type
+         (for-home
+          (dicod-configuration @dots{})))
+@end lisp
+
 @node Invoking guix home
 @section Invoking @command{guix home}
 
diff --git a/gnu/home/services/dict.scm b/gnu/home/services/dict.scm
new file mode 100644
index 0000000000..b8a4653276
--- /dev/null
+++ b/gnu/home/services/dict.scm
@@ -0,0 +1,32 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2023 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu home services dict)
+  #:use-module (gnu home services)
+  #:use-module (gnu services)
+  #:use-module (gnu services dict)
+  #:use-module ((gnu system shadow) #:select (account-service-type))
+  #:export (home-dicod-service-type)
+  #:re-export (dicod-configuration))
+
+(define home-dicod-service-type
+  (service-type
+   (inherit (system->home-service-type
+             (remove-service-extensions dicod-service-type
+                                        (list account-service-type))))
+   (default-value (for-home (dicod-configuration)))))
diff --git a/gnu/local.mk b/gnu/local.mk
index e4f5b2078a..a85f9561a6 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -91,6 +91,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/home.scm					\
   %D%/home/services.scm			\
   %D%/home/services/desktop.scm			\
+  %D%/home/services/dict.scm			\
   %D%/home/services/symlink-manager.scm		\
   %D%/home/services/fontutils.scm		\
   %D%/home/services/gnupg.scm			\
diff --git a/gnu/services/dict.scm b/gnu/services/dict.scm
index f542921302..a4e25f5302 100644
--- a/gnu/services/dict.scm
+++ b/gnu/services/dict.scm
@@ -56,7 +56,9 @@
   (handlers    dicod-configuration-handlers       ;list of <dicod-handler>
                (default '()))
   (databases   dicod-configuration-databases      ;list of <dicod-database>
-               (default (list %dicod-database:gcide))))
+               (default (list %dicod-database:gcide)))
+  (home-service? dicod-configuration-home-service? ;boolean
+                 (default for-home?) (innate)))
 
 (define-record-type* <dicod-handler>
   dicod-handler make-dicod-handler
@@ -152,20 +154,26 @@ database {
 (define (dicod-shepherd-service config)
   (let* ((dicod.conf (dicod-configuration-file config))
          (interfaces (dicod-configuration-interfaces config))
+         (home-service? (dicod-configuration-home-service? config))
+         (mappings  `(,@(if home-service?
+                            '()
+                            (list (file-system-mapping
+                                   (source "/dev/log")
+                                   (target source))))
+                      ,(file-system-mapping
+                        (source dicod.conf)
+                        (target source))))
          (dicod      (least-authority-wrapper
                       (file-append (dicod-configuration-dico config)
                                    "/bin/dicod")
                       #:name "dicod"
-                      #:mappings (list (file-system-mapping
-                                        (source "/dev/log")
-                                        (target source))
-                                       (file-system-mapping
-                                        (source dicod.conf)
-                                        (target source)))
+                      #:mappings mappings
                       #:namespaces (delq 'net %namespaces))))
     (list (shepherd-service
            (provision '(dicod))
-           (requirement '(user-processes))
+           (requirement (if home-service?
+                            '()
+                            '(user-processes)))
            (documentation "Run the dicod daemon.")
            (start #~(make-inetd-constructor
                      (list #$dicod "--inetd" "--foreground"
@@ -176,7 +184,8 @@ database {
                               (car (getaddrinfo interface "dict")))))
                           '#$interfaces)
                      #:requirements '#$requirement
-                     #:user "dicod" #:group "dicod"
+                     #:user #$(and (not home-service?) "dicod")
+                     #:group #$(and (not home-service?) "dicod")
                      #:service-name-stem "dicod"))
            (stop #~(make-inetd-destructor))
            (actions (list (shepherd-configuration-action dicod.conf)))))))