[bug#28059] [PATCH] gnu: Add mpd service.

[Peter Mikkelsen <petermikkelsen10@gmail.com>]

* doc/guix.text: Add documentation.
* gnu/services/music.scm (<mpd-configuration>): New record type.
  (mpd-service): New service extension.
  (mpd-service-type): New service type.
* gnu/tests/music.scm: New file.
* gnu/local.mk: Add new files.
---
 doc/guix.texi          | 53 +++++++++++++++++++++++++++++++
 gnu/local.mk           |  2 ++
 gnu/services/music.scm | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++
 gnu/tests/music.scm    | 83 +++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 222 insertions(+)
 create mode 100644 gnu/services/music.scm
 create mode 100644 gnu/tests/music.scm

diff --git a/doc/guix.texi b/doc/guix.texi
index 8f14ddd50..e565dfdc9 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -227,6 +227,7 @@ Services
 * Network File System::         NFS related services.
 * Continuous Integration::      The Cuirass service.
 * Power management Services::   The TLP tool.
+* Music Services::              The MPD.
 * Miscellaneous Services::      Other services.
 
 Defining Services
@@ -9035,6 +9036,7 @@ declaration.
 * Network File System::         NFS related services.
 * Continuous Integration::      The Cuirass service.
 * Power management Services::   The TLP tool.
+* Music Services::              The MPD.
 * Miscellaneous Services::      Other services.
 @end menu
 
@@ -15635,6 +15637,57 @@ Package object of thermald.
 @end table
 @end deftp
 
+@node Music Services
+@subsubsection Music Services
+
+@cindex mpd
+@subsubheading Music Player Daemon
+
+The @code{(gnu services music)} provides a service to start MPD (the Music
+Player Daemon). It uses pulseaudio for output.
+
+@defvr {Scheme Variable} mpd-service-type
+The service type for @command{mpd}
+@end defvr
+
+@deftp {Data Type} mpd-configuration
+Data type representing the configuration of @command{mpd}.
+
+@table @asis
+@item @code{user} (default: @code{"mpd"})
+The user to run mpd as.
+
+@item @code{music-dir} (default: @code{"~/Music"})
+The directory to scan for music files.
+
+@item @code{playlist-dir} (default: @code{"~/.mpd/playlists"})
+The directory to store playlists.
+
+@item @code{pid-file} (default: @code{"~/.mpd-pid"})
+The file mpd wil store its PID.
+
+@item @code{port} (default: @code{"6600"})
+The port to run mpd on.
+
+@item @code{address} (default: @code{"any"})
+The address that mpd will bind to. To use a Unix domain socket,
+an absolute path can be specified here.
+
+@end table
+@end deftp
+
+@deffn {Scheme Procedure} mpd-service [#:config (mpd-configuration)]
+Return a service that runs @code{mpd} using @var{configuration},
+a @code{<mpd-configuration>} object.
+
+The following example shows how one might run @code{mpd} as user
+@code{"bob"} on port @code{6666}.
+@example
+(mpd-service (mpd-configuration
+              (user "bob")
+              (port "6666")))
+@end example
+@end deffn
 
 @node Miscellaneous Services
 @subsubsection Miscellaneous Services
diff --git a/gnu/local.mk b/gnu/local.mk
index b1ff72d6a..cad0ba38d 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -441,6 +441,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/services/mail.scm				\
   %D%/services/mcron.scm			\
   %D%/services/messaging.scm			\
+  %D%/services/music.scm                        \
   %D%/services/networking.scm			\
   %D%/services/nfs.scm			\
   %D%/services/shepherd.scm			\
@@ -488,6 +489,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/tests/install.scm				\
   %D%/tests/mail.scm				\
   %D%/tests/messaging.scm			\
+  %D%/tests/music.scm				\
   %D%/tests/networking.scm			\
   %D%/tests/ssh.scm				\
   %D%/tests/web.scm
diff --git a/gnu/services/music.scm b/gnu/services/music.scm
new file mode 100644
index 000000000..77912d5c6
--- /dev/null
+++ b/gnu/services/music.scm
@@ -0,0 +1,84 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2017 Peter Mikkelsen <petermikkelsen10@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 music)
+  #:use-module (guix gexp)
+  #:use-module (gnu services)
+  #:use-module (gnu services shepherd)
+  #:use-module (gnu packages mpd)
+  #:use-module (guix records)
+  #:export (mpd-configuration
+            mpd-configuration?
+            mpd-service
+            mpd-service-type))
+
+;;; Commentary:
+;;;
+;;; Music related services
+;;;
+;;; Code:
+
+(define-record-type* <mpd-configuration>
+  mpd-configuration make-mpd-configuration
+  mpd-configuration?
+  (user         mpd-configuration-user
+                (default "mpd"))
+  (music-dir    mpd-configuration-music-dir
+                (default "~/Music"))
+  (playlist-dir mpd-configuration-playlist-dir
+                (default "~/.mpd/playlists"))
+  (port         mpd-configuration-port
+                (default "6600"))
+  (address      mpd-configuration-address
+                (default "any"))
+  (pid-file     mpd-configuration-pid-file
+                (default "~/.mpd-pid")))
+
+(define (mpd-config->file config)
+  (apply
+   mixed-text-file "mpd.conf"
+   "audio_output {\n"
+   "  type \"pulse\"\n"
+   "  name \"MPD\"\n"
+   "}\n"
+   (map (lambda (config-line)
+          (let ((config-name (car config-line))
+                (config-val (cadr config-line)))
+            (string-append config-name " \"" (config-val config) "\"\n")))
+        `(("user" ,mpd-configuration-user)
+          ("music_directory" ,mpd-configuration-music-dir)
+          ("playlist_directory" ,mpd-configuration-playlist-dir)
+          ("port" ,mpd-configuration-port)
+          ("bind_to_address" ,mpd-configuration-address)
+          ("pid_file" ,mpd-configuration-pid-file)))))
+
+(define mpd-service-type
+  (shepherd-service-type
+   'mpd
+   (lambda (config)
+     (shepherd-service
+      (documentation "Run the MPD (Music Player Daemon)")
+      (provision '(mpd))
+      (start #~(make-forkexec-constructor
+                (list #$(file-append mpd "/bin/mpd")
+                      "--no-daemon"
+                      #$(mpd-config->file config))))
+      (stop  #~(make-kill-destructor))))))
+
+(define* (mpd-service #:optional (config (mpd-configuration)))
+  (service mpd-service-type config))
diff --git a/gnu/tests/music.scm b/gnu/tests/music.scm
new file mode 100644
index 000000000..158513098
--- /dev/null
+++ b/gnu/tests/music.scm
@@ -0,0 +1,83 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2017 Peter Mikkelsen <petermikkelsen10@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 tests music)
+  #:use-module (gnu tests)
+  #:use-module (gnu system)
+  #:use-module (gnu system vm)
+  #:use-module (gnu services)
+  #:use-module (gnu services music)
+  #:use-module (gnu packages mpd)
+  #:use-module (guix gexp)
+  #:export (%test-mpd))
+
+(define %mpd-os
+  (simple-operating-system
+   (mpd-service (mpd-configuration
+                 (user "root")))))
+
+(define (run-mpd-test)
+  "Run tests in %mpd-os, which has mpd running."
+  (define os
+    (marionette-operating-system
+     %mpd-os
+     #:imported-modules '((gnu services herd))))
+
+  (define vm
+    (virtual-machine os))
+
+  (define test
+    (with-imported-modules '((gnu build marionette))
+      #~(begin
+          (use-modules (srfi srfi-64)
+                       (gnu build marionette))
+          (define marionette
+            (make-marionette (list #$vm)))
+
+          (mkdir #$output)
+          (chdir #$output)
+
+          (test-begin "mpd")
+
+          (test-eq "service is running"
+            'running!
+            (marionette-eval
+             '(begin
+                (use-modules (gnu services herd))
+                (start-service 'mpd)
+                'running!)
+             marionette))
+
+          (test-assert "pid file"
+            (wait-for-file "/root/.mpd-pid"
+             marionette))
+
+          (test-assert "mpc connect"
+            (marionette-eval
+             '(zero? (system #$(file-append mpd-mpc "/bin/mpc")))
+             marionette))
+
+          (test-end)
+          (exit (= (test-runner-fail-count (test-runner-current)) 0)))))
+  (gexp->derivation "mpd-test" test))
+
+(define %test-mpd
+  (system-test
+   (name "mpd")
+   (description "Test that the mpd can run and be connected to.")
+   (value (run-mpd-test))))
-- 
2.14.0