bind: Enable backup/restore

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

functional_tests/features/bind.feature

@@ -50,3 +50,15 @@ Scenario: Disable bind DNSSEC
   And bind DNSSEC is disabled
   When I disable bind DNSSEC
   Then bind DNSSEC should be disabled
+
+Scenario: Backup and restore bind
+  Given the bind application is enabled
+  When I set bind forwarders to 1.1.1.1
+  And I disable bind DNSSEC
+  And I create a backup of the bind app data
+  And I set bind forwarders to 1.0.0.1
+  And I enable bind DNSSEC
+  And I export the bind app data backup
+  And I restore the bind app data backup
+  Then bind forwarders should be 1.1.1.1
+  And bind DNSSEC should be disabled

plinth/modules/bind/__init__.py

@@ -29,6 +29,8 @@ from plinth import service as service_module
 from plinth.menu import main_menu
 from plinth.utils import format_lazy
 
+from .manifest import backup
+
 version = 1
 
 name = _('BIND')

plinth/modules/bind/manifest.py

@@ -0,0 +1,28 @@
+#
+# This file is part of FreedomBox.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program 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 Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+"""
+Application manifest for bind.
+"""
+
+from plinth.modules.backups.api import validate as validate_backup
+
+backup = validate_backup({
+    'config': {
+        'files': ['/etc/bind/named.conf.options']
+    },
+    'services': ['bind9']
+})