storage: Show low disk space warning using notifications API

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

plinth/modules/storage/__init__.py

@@ -17,15 +17,17 @@
 """
 FreedomBox app to manage storage.
 """
+
 import logging
 import subprocess
 
 import psutil
 from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import ugettext_noop
 
 from plinth import actions
 from plinth import app as app_module
-from plinth import cfg, menu, utils
+from plinth import cfg, glib, menu, utils
 from plinth.daemon import Daemon
 from plinth.errors import ActionError, PlinthError
 from plinth.utils import format_lazy, import_from_gi
@@ -72,6 +74,9 @@ class StorageApp(app_module.App):
         daemon = Daemon('daemon-udiskie', managed_services[0])
         self.add(daemon)
 
+        # Check every hour for low disk space
+        glib.schedule(3600, warn_about_low_disk_space)
+
 
 def init():
     """Initialize the module."""
@@ -288,3 +293,54 @@ def setup(helper, old_version=None):
             expand_partition(root_device)
         except ActionError:
             pass
+
+
+def warn_about_low_disk_space(request):
+    """Warn about insufficient space on root partition."""
+    from plinth.notification import Notification
+
+    try:
+        root_info = get_disk_info('/')
+    except PlinthError as exception:
+        logger.exception('Error getting information about root partition: %s',
+                         exception)
+        return
+
+    show = False
+    if root_info['percent_used'] > 90 or root_info['free_gib'] < 1:
+        severity = 'error'
+        show = True
+    elif root_info['percent_used'] > 75 or root_info['free_gib'] < 2:
+        severity = 'warning'
+        show = True
+
+    if not show:
+        try:
+            Notification.get('storage-low-disk-space').delete()
+        except KeyError:
+            pass
+    else:
+        # Translators: xgettext:no-python-format
+        message = ugettext_noop(
+            'Low space on system partition: {percent_used}% used, '
+            '{free_space} free.')
+        title = ugettext_noop('Low disk space')
+        data = {
+            'app_icon': 'fa-hdd-o',
+            'app_name': ugettext_noop('Storage'),
+            'percent_used': root_info['percent_used'],
+            'free_space': format_bytes(root_info['free_bytes'])
+        }
+        actions = [{
+            'type': 'link',
+            'class': 'primary',
+            'text': 'Go to {app_name}',
+            'url': 'storage:index'
+        }, {
+            'type': 'dismiss'
+        }]
+        Notification.update_or_create(id='storage-low-disk-space',
+                                      app_id='storage', severity=severity,
+                                      title=title, message=message,
+                                      actions=actions, data=data,
+                                      group='admin')

plinth/modules/storage/views.py

@@ -30,11 +30,9 @@ from django.utils.translation import ugettext as _
 from django.views.decorators.http import require_POST
 
 from plinth import actions, views
-from plinth.errors import PlinthError
 from plinth.modules import storage
-from plinth.utils import format_lazy, is_user_admin
 
-from . import get_disk_info, get_error_message
+from . import get_error_message
 
 logger = logging.getLogger(__name__)
 
@@ -48,11 +46,6 @@ class StorageAppView(views.AppView):
     template_name = 'storage.html'
     show_status_block = False
 
-    def render_to_response(self, context, **response_kwargs):
-        """Add disk space warning to the view."""
-        warn_about_low_disk_space(self.request)
-        return super().render_to_response(context, **response_kwargs)
-
     def get_context_data(self, *args, **kwargs):
         """Return template context data."""
         context = super().get_context_data(*args, **kwargs)
@@ -98,31 +91,6 @@ def expand_partition(request, device):
         messages.success(request, _('Partition expanded successfully.'))
 
 
-def warn_about_low_disk_space(request):
-    """Warn about insufficient space on root partition."""
-    if not is_user_admin(request, cached=True):
-        return
-
-    try:
-        root_info = get_disk_info('/')
-    except PlinthError as exception:
-        logger.exception('Error getting information about root partition: %s',
-                         exception)
-        return
-
-    message = format_lazy(
-        # Translators: xgettext:no-python-format
-        _('Warning: Low space on system partition ({percent_used}% used, '
-          '{free_space} free).'),
-        percent_used=root_info['percent_used'],
-        free_space=storage.format_bytes(root_info['free_bytes']))
-
-    if root_info['percent_used'] > 90 or root_info['free_gib'] < 1:
-        messages.error(request, message)
-    elif root_info['percent_used'] > 75 or root_info['free_gib'] < 2:
-        messages.warning(request, message)
-
-
 @require_POST
 def eject(request, device_path):
     """Eject a device, given its path.

plinth/views.py

@@ -64,9 +64,6 @@ def index(request):
     ]
     selected_shortcut = selected_shortcut[0] if selected_shortcut else None
 
-    from plinth.modules.storage import views as disk_views
-    disk_views.warn_about_low_disk_space(request)
-
     return TemplateResponse(
         request, 'index.html', {
             'title': _('FreedomBox'),
@@ -88,8 +85,6 @@ class AppsIndexView(TemplateView):
 
 def system_index(request):
     """Serve the system index page."""
-    from plinth.modules.storage import views as disk_views
-    disk_views.warn_about_low_disk_space(request)
     return TemplateResponse(request, 'system.html',
                             {'advanced_mode': get_advanced_mode()})