Option to enable/disble automatic timeline snapshots

Signed-off-by: Hanisha P<hanishap@thoughtworks.com>
Reviewed-by: Joseph Nuthalapati <njoseph@thoughtworks.com>

actions/snapshot

@@ -38,6 +38,7 @@ def parse_arguments():
     subparsers.add_parser('setup', help='Configure snapper')
     subparsers.add_parser('list', help='List snapshots')
     subparsers.add_parser('create', help='Create snapshot')
+    subparsers.add_parser('get-config', help='Configurations of snapshot')
 
     subparser = subparsers.add_parser('delete',
                                       help='Delete a snapshot by number')
@@ -46,6 +47,10 @@ def parse_arguments():
     subparser = subparsers.add_parser('delete-all',
                                       help='Delete all the snapshots')
 
+    subparser = subparsers.add_parser('configure',
+                                      help='Configure automatic snapshots')
+    subparser.add_argument('config')
+
     subparser = subparsers.add_parser('rollback', help='Rollback to snapshot')
     subparser.add_argument('number', help='Number of snapshot to rollback to')
 
@@ -163,6 +168,22 @@ def subcommand_delete_all(_):
         subprocess.run(command, check=True)
 
 
+def subcommand_configure(arguments):
+    command = ['snapper', 'set-config', arguments.config]
+    subprocess.run(command, check=True)
+
+
+def subcommand_get_config(_):
+    command = ['snapper', 'get-config']
+    process = subprocess.run(command, stdout=subprocess.PIPE, check=True)
+    lines = process.stdout.decode().splitlines()
+    config = {}
+    for line in lines[2:]:
+        parts = [part.strip() for part in line.split('|')]
+        config[parts[0]] = parts[1]
+    print(json.dumps(config))
+
+
 def subcommand_rollback(arguments):
     """Rollback to snapshot."""
     command = [

plinth/modules/snapshot/__init__.py

@@ -23,6 +23,7 @@ from django.utils.translation import ugettext_lazy as _
 
 from plinth import actions
 from plinth.menu import main_menu
+import json
 
 
 version = 1
@@ -58,3 +59,11 @@ def setup(helper, old_version=None):
     """Install and configure the module."""
     helper.install(managed_packages)
     helper.call('post', actions.superuser_run, 'snapshot', ['setup'])
+
+
+def is_timeline_snapshots_enabled():
+    """Return whether timeline snapshots are enabled."""
+    output = actions.superuser_run('snapshot', ['get-config'])
+    output = json.loads(output)
+    return output['TIMELINE_CREATE'] == "yes"
+

plinth/modules/snapshot/forms.py

@@ -0,0 +1,29 @@
+#
+# This file is part of Plinth.
+#
+# 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/>.
+#
+"""
+Forms for snapshot module.
+"""
+
+from django import forms
+from django.utils.translation import ugettext_lazy as _
+
+
+class SnapshotForm(forms.Form):
+    enable_timeline_snapshots = forms.BooleanField(
+        label=_('Enable Timeline Snapshots'), required=False, help_text=_(
+            'Uncheck this to disable timeline snapshots '
+            '(hourly, daily, monthly and yearly).'))

plinth/modules/snapshot/templates/snapshot.html

@@ -23,27 +23,32 @@
 
 {% block configuration %}
   <p>
-    <div class="row">
-      <form class="form" method="post">
-        {% csrf_token %}
+    <form class="form" method="post">
+      {% csrf_token %}
+      <h3>{% trans "Configuration" %}</h3>
+      {{ form|bootstrap }}
+      <input type="submit" class="btn btn-primary" name="update"
+             value="{% trans "Update setup" %}"/>
+      <hr>
+      <div class="row">
         <div class="col-xs-6 text-left">
-          <input type="submit" class="btn btn-primary"
+          <input type="submit" class="btn btn-primary" name="create"
                  value="{% trans 'Create Snapshot' %}"/>
         </div>
-      </form>
+    </form>
 
-      <div class="col-xs-6 text-right">
-        <a title="{% trans 'Delete all the snapshots' %}"
-           role="button" class="btn btn-danger"
-           {% if snapshots|length == 1 %}
-             disabled="disabled"
-           {% else %}
-             href="{% url 'snapshot:delete-all' %}"
-           {% endif %}>
-          {% trans 'Delete All' %}
-        </a>
-      </div>
+    <div class="col-xs-6 text-right">
+      <a title="{% trans 'Delete all the snapshots' %}"
+         role="button" class="btn btn-danger"
+         {% if snapshots|length == 1 %}
+         disabled="disabled"
+         {% else %}
+         href="{% url 'snapshot:delete-all' %}"
+         {% endif %}>
+        {% trans 'Delete All' %}
+      </a>
     </div>
+      </div>
   </p>
 
   <div class="row">

plinth/modules/snapshot/views.py

@@ -27,14 +27,27 @@ from django.urls import reverse
 from django.utils.translation import ugettext as _
 
 from plinth import actions
+from plinth.errors import ActionError
 from plinth.modules import snapshot as snapshot_module
 
+from . import is_timeline_snapshots_enabled
+from .forms import SnapshotForm
+
 
 def index(request):
     """Show snapshot list."""
+    status = get_status()
     if request.method == 'POST':
-        actions.superuser_run('snapshot', ['create'])
-        messages.success(request, _('Created snapshot.'))
+        form = SnapshotForm(request.POST, prefix='snapshot')
+        if 'create' in request.POST:
+            actions.superuser_run('snapshot', ['create'])
+            messages.success(request, _('Created snapshot.'))
+        if 'update' in request.POST and form.is_valid():
+            _apply_changes(request, status, form.cleaned_data)
+            status = get_status()
+            form = SnapshotForm(initial=status, prefix='snapshot')
+    else:
+        form = SnapshotForm(initial=status, prefix='snapshot')
 
     output = actions.superuser_run('snapshot', ['list'])
     snapshots = json.loads(output)
@@ -42,7 +55,8 @@ def index(request):
     return TemplateResponse(request, 'snapshot.html', {
         'title': snapshot_module.name,
         'description': snapshot_module.description,
-        'snapshots': snapshots
+        'snapshots': snapshots,
+        'form': form
     })
 
 
@@ -50,9 +64,8 @@ def delete(request, number):
     """Show confirmation to delete a snapshot."""
     if request.method == 'POST':
         actions.superuser_run('snapshot', ['delete', number])
-        messages.success(request,
-                         _('Deleted snapshot #{number}.').format(
-                             number=number))
+        messages.success(
+            request, _('Deleted snapshot #{number}.').format(number=number))
         return redirect(reverse('snapshot:index'))
 
     output = actions.superuser_run('snapshot', ['list'])
@@ -85,9 +98,9 @@ def rollback(request, number):
     """Show confirmation to rollback to a snapshot."""
     if request.method == 'POST':
         actions.superuser_run('snapshot', ['rollback', number])
-        messages.success(request,
-                         _('Rolled back to snapshot #{number}.').format(
-                             number=number))
+        messages.success(
+            request,
+            _('Rolled back to snapshot #{number}.').format(number=number))
         messages.warning(
             request,
             _('The system must be restarted to complete the rollback.'))
@@ -105,3 +118,27 @@ def rollback(request, number):
         'title': _('Rollback to Snapshot'),
         'snapshot': snapshot
     })
+
+
+def get_status():
+    return {'enable_timeline_snapshots': is_timeline_snapshots_enabled()}
+
+
+def _apply_changes(request, old_status, new_status):
+    """Try to apply changes and handle errors."""
+    try:
+        __apply_changes(request, old_status, new_status)
+    except ActionError as exception:
+        messages.error(request,
+                       _('Action error: {0} [{1}] [{2}]').format(
+                           exception.args[0], exception.args[1],
+                           exception.args[2]))
+
+
+def __apply_changes(request, old_status, new_status):
+    if old_status['enable_timeline_snapshots'] != new_status['enable_timeline_snapshots']:
+        timeline_create = "TIMELINE_CREATE=yes" if new_status[
+            'enable_timeline_snapshots'] else "TIMELINE_CREATE=no"
+        actions.superuser_run('snapshot', ['configure', timeline_create])
+        messages.success(request,
+                         _('Timeline Snapshots configuration updated'))