mumble: Implement backup/restore

Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

functional_tests/features/mumble.feature

@@ -15,7 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-@apps @mumble
+@apps @mumble @backups
 Feature: Mumble Voice Chat
   Run Mumble voice chat server.
 
@@ -32,3 +32,12 @@ Scenario: Disable mumble application
   Given the mumble application is enabled
   When I disable the mumble application
   Then the mumble service should not be running
+
+# TODO: Improve this to actually check that data such as rooms, identity or
+# certificates are restored.
+Scenario: Backup and restore mumble
+  Given the mumble application is enabled
+  When I create a backup of the mumble app data
+  And I export the mumble app data backup
+  And I restore the mumble app data backup
+  Then the mumble service should be running

plinth/modules/mumble/__init__.py

@@ -26,7 +26,7 @@ from plinth import action_utils, actions, frontpage
 from plinth.menu import main_menu
 from plinth.views import ServiceView
 
-from .manifest import clients
+from .manifest import backup, clients
 
 version = 1
 

plinth/modules/mumble/manifest.py

@@ -18,6 +18,7 @@
 from django.utils.translation import ugettext_lazy as _
 
 from plinth.clients import store_url, validate
+from plinth.modules.backups.api import validate as validate_backup
 
 _plumble_package_id = 'com.morlunk.mumbleclient'
 
@@ -70,3 +71,9 @@ clients = validate([{
         'url': 'https://itunes.apple.com/dk/app/mumblefy/id858752232'
     }]
 }])
+
+backup = validate_backup({
+    'data': {
+        'directories': ['/var/lib/mumble-server']
+    }
+})