gnu: services: Add dicod-service.

* gnu/services/dict.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
* doc/guix.texi (Various Services): Document it.

doc/guix.texi

@@ -9395,6 +9395,55 @@ Finally, @var{extra-options} is a list of additional command-line options
 passed to @command{lircd}.
 @end deffn
 
+@subsubsection Dictionary Services
+The @code{(gnu services dict)} module provides the following service:
+
+@deffn {Scheme Procedure} dicod-service [#:config (dicod-configuration)]
+Return a service that runs the @command{dicod} daemon, an implementation
+of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
+
+The optional @var{config} argument specifies the configuration for
+@command{dicod}, which should be a @code{<dicod-configuration>} object, by
+default it serves the GNU Collaborative International Dictonary of English.
+
+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 deffn
+
+@deftp {Data Type} dicod-configuration
+Data type representing the configuration of dicod.
+
+@table @asis
+@item @code{dico} (default: @var{dico})
+Package object of the GNU Dico dictionary server.
+
+@item @code{databases} (default: @var{(list %dicod-database:gcide)})
+List of @code{<dicod-database>} objects denoting dictionaries to be served.
+@end table
+@end deftp
+
+@deftp {Data Type} dicod-database
+Data type representing a dictionary database.
+
+@table @asis
+@item @code{name}
+Name of the database, will be used in DICT commands.
+
+@item @code{module}
+Name of the dicod module used by this database
+(@pxref{Modules,,, dico, GNU Dico Manual}).
+
+@item @code{options}
+List of strings or gexps representing the arguments for the module handler
+(@pxref{Handlers,,, dico, GNU Dico Manual}).
+@end table
+@end deftp
+
+@defvr {Scheme Variable} %dicod-database:gcide
+A @code{<dicod-database>} object serving the GNU Collaborative International
+Dictonary of English using the @code{gcide} package.
+@end defvr
 
 @node Setuid Programs
 @subsection Setuid Programs

gnu/local.mk

@@ -374,6 +374,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/services/databases.scm			\
   %D%/services/dbus.scm				\
   %D%/services/desktop.scm			\
+  %D%/services/dict.scm				\
   %D%/services/lirc.scm				\
   %D%/services/mail.scm				\
   %D%/services/networking.scm			\

gnu/services/dict.scm

@@ -0,0 +1,131 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2016 Sou Bunnbu <iyzsong@gmail.com>
+;;;
+;;; 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 services dict)
+  #:use-module (guix gexp)
+  #:use-module (guix records)
+  #:use-module (gnu services)
+  #:use-module (gnu services shepherd)
+  #:use-module (gnu system shadow)
+  #:use-module ((gnu packages admin) #:select (shadow))
+  #:use-module (gnu packages dico)
+  #:use-module (gnu packages dictionaries)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-26)
+  #:use-module (ice-9 match)
+  #:export (dicod-service
+            dicod-configuration
+            dicod-database
+            %dicod-database:gcide))
+
+
+;;;
+;;; GNU Dico.
+;;;
+
+(define-record-type* <dicod-configuration>
+  dicod-configuration make-dicod-configuration
+  dicod-configuration?
+  (dico        dicod-configuration-dico       (default dico))
+  (databases   dicod-configuration-databases
+               ;; list of <dicod-database>
+               (default (list %dicod-database:gcide))))
+
+(define-record-type* <dicod-database>
+  dicod-database make-dicod-database
+  dicod-database?
+  (name        dicod-database-name)
+  (module      dicod-database-module)
+  (options     dicod-database-options        (default '())))
+
+(define %dicod-database:gcide
+  (dicod-database
+   (name "gcide")
+   (module "gcide")
+   (options (list #~(string-append "dbdir=" #$gcide "/share/gcide")
+                  "idxdir=/var/run/dicod"))))
+
+(define %dicod-accounts
+  (list (user-group
+         (name "dicod")
+         (system? #t))
+        (user-account
+         (name "dicod")
+         (group "dicod")
+         (system? #t)
+         (home-directory "/var/empty")
+         (shell #~(string-append #$shadow "/sbin/nologin")))))
+
+(define (dicod-configuration-file config)
+  (define dicod-configuration->text
+    (match-lambda
+      (($ <dicod-configuration> dico databases)
+       (append-map (match-lambda
+                     (($ <dicod-database> name module options)
+                      `("
+load-module " ,module ";
+database {
+   name \"" ,name "\";
+   handler \"" ,module
+   (string-join (list ,@options) " " 'prefix) "\";
+}\n")))
+                   databases))))
+  (apply mixed-text-file "dicod.conf" (dicod-configuration->text config)))
+
+(define %dicod-activation
+  #~(begin
+      (use-modules (guix build utils))
+      (let ((user   (getpwnam "dicod"))
+            (rundir "/var/run/dicod"))
+        (mkdir-p rundir)
+        (chown rundir (passwd:uid user) (passwd:gid user)))))
+
+(define (dicod-shepherd-service config)
+  (list (shepherd-service
+         (provision '(dicod))
+         (documentation "Run the dicod daemon.")
+         (start #~(make-forkexec-constructor
+                   (list (string-append #$dico "/bin/dicod") "--foreground"
+                         (string-append
+                          "--config=" #$(dicod-configuration-file config)))
+                   #:user "dicod" #:group "dicod"))
+         (stop #~(make-kill-destructor)))))
+
+(define dicod-service-type
+  (service-type
+   (name 'dict)
+   (extensions
+    (list (service-extension account-service-type
+                             (const %dicod-accounts))
+          (service-extension activation-service-type
+                             (const %dicod-activation))
+          (service-extension shepherd-root-service-type
+                             dicod-shepherd-service)))))
+
+(define* (dicod-service #:key (config (dicod-configuration)))
+  "Return a service that runs the @command{dicod} daemon, an implementation
+of DICT server (@pxref{Dicod,,, dico, GNU Dico Manual}).
+
+The optional @var{config} argument specifies the configuration for
+@command{dicod}, which should be a @code{<dicod-configuration>} object, by
+default it serves the GNU Collaborative International Dictonary of English.
+
+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})."
+  (service dicod-service-type config))