snapper: enable/diable apt snapshots

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

actions/snapshot

@@ -28,6 +28,7 @@ import augeas
 
 FSTAB = '/etc/fstab'
 AUG_FSTAB = '/files/etc/fstab'
+DEFAULT_FILE = '/etc/default/snapper'
 
 
 def parse_arguments():
@@ -54,6 +55,9 @@ def parse_arguments():
     subparser = subparsers.add_parser('rollback', help='Rollback to snapshot')
     subparser.add_argument('number', help='Number of snapshot to rollback to')
 
+    subparser = subparsers.add_parser('disable-apt-snapshot', help='enable/disable apt snapshots')
+    subparser.add_argument('state')
+
     subparsers.required = True
     return parser.parse_args()
 
@@ -155,6 +159,20 @@ def _get_default_snapshot():
     return None
 
 
+def subcommand_disable_apt_snapshot(arguments):
+    """Set flag to Enable/Disable apt software snapshots in config files"""
+
+    """Initialize Augeas."""
+    aug = augeas.Augeas(flags=augeas.Augeas.NO_LOAD +
+                        augeas.Augeas.NO_MODL_AUTOLOAD)
+    aug.set('/augeas/load/Shellvars/lens', 'Shellvars.lns')
+    aug.set('/augeas/load/Shellvars/incl[last() + 1]', DEFAULT_FILE)
+    aug.load()
+
+    aug.set('/files' + DEFAULT_FILE + '/DISABLE_APT_SNAPSHOT', arguments.state)
+    aug.save()
+
+
 def subcommand_create(_):
     """Create snapshot."""
     command = ['snapper', 'create', '--description', 'manually created']

plinth/modules/snapshot/__init__.py

@@ -18,6 +18,7 @@
 FreedomBox app to manage filesystem snapshots.
 """
 
+import augeas
 import json
 
 from django.utils.translation import ugettext_lazy as _
@@ -25,7 +26,7 @@ from django.utils.translation import ugettext_lazy as _
 from plinth import actions
 from plinth.menu import main_menu
 
-version = 3
+version = 4
 
 managed_packages = ['snapper']
 
@@ -52,6 +53,8 @@ service = None
 
 manual_page = 'Snapshots'
 
+DEFAULT_FILE = '/etc/default/snapper'
+
 
 def init():
     """Initialize the module."""
@@ -65,7 +68,26 @@ def setup(helper, old_version=None):
     helper.call('post', actions.superuser_run, 'snapshot', ['setup'])
 
 
+def load_augeas():
+    """Initialize Augeas."""
+    aug = augeas.Augeas(flags=augeas.Augeas.NO_LOAD +
+                        augeas.Augeas.NO_MODL_AUTOLOAD)
+
+    # shell-script config file lens
+    aug.set('/augeas/load/Shellvars/lens', 'Shellvars.lns')
+    aug.set('/augeas/load/Shellvars/incl[last() + 1]', DEFAULT_FILE)
+    aug.load()
+    return aug
+
+
+def is_apt_snapshots_enabled(aug):
+    """Return whether APT snapshots is enabled."""
+    value = aug.get('/files' + DEFAULT_FILE + '/DISABLE_APT_SNAPSHOT')
+    return value != 'yes'
+
+
 def get_configuration():
+    aug = load_augeas()
     output = actions.superuser_run('snapshot', ['get-config'])
     output = json.loads(output)
 
@@ -75,6 +97,8 @@ def get_configuration():
     return {
         'enable_timeline_snapshots':
             get_boolean_choice(output['TIMELINE_CREATE'] == 'yes'),
+        'enable_software_snapshots':
+            get_boolean_choice(is_apt_snapshots_enabled(aug)),
         'hourly_limit':
             output['TIMELINE_LIMIT_HOURLY'],
         'daily_limit':

plinth/modules/snapshot/forms.py

@@ -29,6 +29,11 @@ class SnapshotForm(forms.Form):
                     '(hourly, daily, monthly and yearly).'),
         choices=[('yes', 'Enabled'), ('no', 'Disabled')])
 
+    enable_software_snapshots = forms.ChoiceField(
+        label=_('Software Snapshots'),
+        help_text=_('Enable or disable software snapshots '),
+        choices=[('yes', 'Enabled'), ('no', 'Disabled')])
+
     hourly_limit = forms.IntegerField(
         label=_('Hourly Snapshots Limit'), min_value=0,
         help_text=_('Keep a maximum of this many hourly snapshots.'))

plinth/modules/snapshot/views.py

@@ -108,6 +108,12 @@ def update_configuration(request, old_status, new_status):
                         ('number_min_age', 'NUMBER_MIN_AGE={}'),
                     ]))
 
+    if old_status['enable_software_snapshots'] != new_status['enable_software_snapshots']:
+        if new_status['enable_software_snapshots'] == 'yes':
+            actions.superuser_run('snapshot', ['disable-apt-snapshot', 'no'])
+        else:
+            actions.superuser_run('snapshot', ['disable-apt-snapshot', 'yes'])
+
     try:
         actions.superuser_run('snapshot', ['set-config', " ".join(config)])