backups: Trigger schedules every hour

- This will lead to backups only once a day or so.

- In case of errors, backups are tried every hour.

- Cleanups are also triggered but cleanups happen only after a successful
backup.

Tests performed:

- In development mode, a new backup is taken after 3 minutes of enabling a
repository's schedule.

- Error in one repository does not effect the backup of other repositories.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/backups/__init__.py

@@ -4,6 +4,7 @@ FreedomBox app to manage backup archives.
 """
 
 import json
+import logging
 import os
 import pathlib
 import re
@@ -14,10 +15,12 @@ from django.utils.translation import ugettext_lazy as _
 
 from plinth import actions
 from plinth import app as app_module
-from plinth import cfg, menu
+from plinth import cfg, glib, menu
 
 from . import api
 
+logger = logging.getLogger(__name__)
+
 version = 2
 
 is_essential = True
@@ -56,6 +59,11 @@ class BackupsApp(app_module.App):
                               'backups:index', parent_url_name='system')
         self.add(menu_item)
 
+        # Check every hour (every 3 minutes in debug mode) to perform scheduled
+        # backups.
+        interval = 180 if cfg.develop else 3600
+        glib.schedule(interval, backup_by_schedule)
+
 
 def setup(helper, old_version=None):
     """Install and configure the module."""
@@ -98,6 +106,17 @@ def _backup_handler(packet, encryption_passphrase=None):
     actions.superuser_run('backups', arguments, input=input_data.encode())
 
 
+def backup_by_schedule(data):
+    """Check if backups need to be taken and run the operation."""
+    from . import repository as repository_module
+    for repository in repository_module.get_repositories():
+        try:
+            repository.schedule.run_schedule()
+        except Exception as exception:
+            logger.exception('Error running scheduled backup: %s', exception)
+            # XXX: Create a notification
+
+
 def get_exported_archive_apps(path):
     """Get list of apps included in exported archive file."""
     arguments = ['get-exported-archive-apps', '--path', path]