[fix] Fixed DeviceMetricView: allow readonly

openwisp_monitoring/device/api/views.py

@@ -8,6 +8,7 @@
 from django.core.exceptions import ValidationError
 from django.db.models import Count, Q
 from django.db.models.functions import Round
+from django.http import Http404
 from django.utils.timezone import now
 from django.utils.translation import gettext_lazy as _
 from django_filters.rest_framework import DjangoFilterBackend
@@ -111,7 +112,7 @@ class DeviceMetricView(
 
     model = DeviceData
     queryset = (
-        DeviceData.objects.filter(organization__is_active=True, _is_deactivated=False)
+        DeviceData.objects.filter(organization__is_active=True)
         .only(
             'id',
             'key',
@@ -173,6 +174,11 @@ def get_object(self, pk):
 
     def post(self, request, pk):
         self.instance = self.get_object(pk)
+        if self.instance._is_deactivated:
+            # If the device is deactivated, do not accept data.
+            # We don't use "Device.is_deactivated()" to avoid
+            # generating query for the related config.
+            raise Http404
         self.instance.data = request.data
         # validate incoming data
         try:

openwisp_monitoring/device/apps.py

@@ -155,16 +155,6 @@ def connect_device_signals(self):
             sender=Device,
             dispatch_uid='device_deactivated_update_devicemonitoring',
         )
-        device_deactivated.connect(
-            DeviceMetricView.invalidate_get_device_cache,
-            sender=Device,
-            dispatch_uid=('deactivate_device_invalidate_view_device_cache'),
-        )
-        device_deactivated.connect(
-            DeviceMetricView.invalidate_get_charts_cache,
-            sender=Device,
-            dispatch_uid=('deactivate_device_invalidate_view_charts_cache'),
-        )
 
     @classmethod
     def device_post_save_receiver(cls, instance, created, **kwargs):

openwisp_monitoring/device/tests/test_api.py

@@ -177,16 +177,15 @@ def test_200_none(self):
     def test_200_create(self):
         self.create_test_data(no_resources=True)
 
-    def test_device_deactivate_cache_invalidation(self):
-        device = self._create_device()
-        # Ensure device ID is cached by the view
-        data = {'type': 'DeviceMonitoring'}
-        response = self._post_data(device.id, device.key, data)
-        self.assertEqual(response.status_code, 200)
+    def test_deactivated_device_read_only(self):
+        self.create_test_data(no_resources=True)
+        device = self.device_model.objects.first()
         device.deactivate()
-
-        response = self._post_data(device.id, device.key, data)
+        response = self._post_data(device.id, device.key, {'type': 'DeviceMonitoring'})
         self.assertEqual(response.status_code, 404)
+        # Read requests should continue to work
+        response = self.client.get(self._url(device.pk, device.key))
+        self.assertEqual(response.status_code, 200)
 
     @patch('openwisp_monitoring.device.tasks.write_device_metrics.delay')
     def test_background_write(self, mocked_task):