[fix] Avoid logging error for Device without DeviceConnection #249

Don't log error on device change page if the device does not
have any DeviceConnection objects.

Closes #249

openwisp_firmware_upgrader/admin.py

@@ -43,6 +43,7 @@
 Category = load_model('Category')
 Build = load_model('Build')
 Device = swapper.load_model('config', 'Device')
+DeviceConnection = swapper.load_model('connection', 'DeviceConnection')
 
 
 class BaseAdmin(MultitenantAdminMixin, TimeReadonlyAdminMixin, admin.ModelAdmin):
@@ -422,8 +423,13 @@ def _get_conditional_queryset(self, request, obj, select_related=False):
     def get_formset(self, request, obj=None, **kwargs):
         formset = super().get_formset(request, obj=obj, **kwargs)
         if obj:
-            schema = get_upgrader_schema_for_device(obj)
-            formset.extra_context = json.dumps(schema, cls=DjangoJSONEncoder)
+            try:
+                schema = get_upgrader_schema_for_device(obj)
+                formset.extra_context = json.dumps(schema, cls=DjangoJSONEncoder)
+            except DeviceConnection.DoesNotExist:
+                # We cannot retrieve the schema for upgrade options because this
+                # device does not have any related DeviceConnection object.
+                pass
         return formset
 
 

openwisp_firmware_upgrader/base/models.py

@@ -308,7 +308,7 @@ def clean(self):
                 _(
                     'This device does not have a related connection object defined '
                     'yet and therefore it would not be possible to upgrade it, '
-                    'please add one in the section named "DEVICE CONNECTIONS"'
+                    'please add one in the section named "Credentials"'
                 )
             )
         if self.device.model not in self.image.boards:

openwisp_firmware_upgrader/templates/admin/firmware_upgrader/device_firmware_inline.html

@@ -1,5 +1,5 @@
 {% include "admin/edit_inline/stacked.html" %}
 
 <script>
-var firmwareUpgraderSchema = {{ inline_admin_formset.formset.extra_context | safe }}
+var firmwareUpgraderSchema = {{ inline_admin_formset.formset.extra_context | default:"null" | safe }}
 </script>

openwisp_firmware_upgrader/tests/test_admin.py

@@ -21,6 +21,7 @@
     admin,
 )
 from openwisp_users.tests.utils import TestMultitenantAdminMixin
+from openwisp_utils.tests import capture_stderr
 
 from ..hardware import REVERSE_FIRMWARE_IMAGE_MAP
 from ..swapper import load_model
@@ -319,6 +320,27 @@ def test_save_device_with_deleted_devicefirmware(self):
         )
         self.assertEqual(response.status_code, 200)
 
+    @capture_stderr()
+    @mock.patch(
+        'openwisp_firmware_upgrader.utils.get_upgrader_class_from_device_connection'
+    )
+    def test_device_firmware_upgrade_without_device_connection(
+        self, captured_stderr, mocked_func, *args
+    ):
+        self._login()
+        device_fw = self._create_device_firmware()
+        device = device_fw.device
+        device.deviceconnection_set.all().delete()
+        response = self.client.get(
+            reverse('admin:config_device_change', args=[device.id])
+        )
+        self.assertNotIn(
+            '\'NoneType\' object has no attribute \'update_strategy\'',
+            captured_stderr.getvalue(),
+        )
+        mocked_func.assert_not_called()
+        self.assertEqual(response.status_code, 200)
+
 
 _mock_updrade = 'openwisp_firmware_upgrader.upgraders.openwrt.OpenWrt.upgrade'
 _mock_connect = 'openwisp_controller.connection.models.DeviceConnection.connect'

openwisp_firmware_upgrader/utils.py

@@ -28,6 +28,8 @@ def get_upgrader_class_for_device(device):
         update_strategy__icontains='ssh',
         enabled=True,
     ).first()
+    if not device_conn:
+        raise device.deviceconnection_set.model.DoesNotExist
     return get_upgrader_class_from_device_connection(device_conn)