Add DNS response code sensor to Gatus integration (#178662)

homeassistant/components/gatus/sensor.py

@@ -33,6 +33,16 @@ class GatusSensorEntityDescription(SensorEntityDescription):
     ]
 
 
+DNS_RCODE_MAP = {
+    "NOERROR": "no_error",
+    "FORMERR": "format_error",
+    "SERVFAIL": "server_failure",
+    "NXDOMAIN": "non_existent_domain",
+    "NOTIMP": "not_implemented",
+    "REFUSED": "refused",
+}
+
+
 SENSOR_TYPES: tuple[GatusSensorEntityDescription, ...] = (
     GatusSensorEntityDescription(
         key="response_time",
@@ -79,6 +89,19 @@ SENSOR_TYPES: tuple[GatusSensorEntityDescription, ...] = (
             else None
         ),
     ),
+    GatusSensorEntityDescription(
+        key="dns_rcode",
+        translation_key="dns_rcode",
+        entity_category=EntityCategory.DIAGNOSTIC,
+        value_fn=lambda coordinator, endpoint: (
+            DNS_RCODE_MAP.get(
+                endpoint.results[-1].dns_rcode,
+                endpoint.results[-1].dns_rcode.lower(),
+            )
+            if endpoint.results and endpoint.results[-1].dns_rcode is not None
+            else None
+        ),
+    ),
 )
 
 
@@ -94,9 +117,16 @@ async def async_setup_entry(
         GatusEndpointSensor(coordinator, entry, endpoint_key, description)
         for endpoint_key, endpoint in coordinator.data.items()
         for description in SENSOR_TYPES
-        if description.key != "certificate_expiration"
-        or (
-            endpoint.results and endpoint.results[-1].certificate_expiration is not None
+        if (
+            description.key != "certificate_expiration"
+            or (
+                endpoint.results
+                and endpoint.results[-1].certificate_expiration is not None
+            )
+        )
+        and (
+            description.key != "dns_rcode"
+            or (endpoint.results and endpoint.results[-1].dns_rcode is not None)
         )
     )
 

homeassistant/components/gatus/strings.json

@@ -61,6 +61,17 @@
       "certificate_expiration": {
         "name": "Certificate expiration"
       },
+      "dns_rcode": {
+        "name": "DNS response code",
+        "state": {
+          "format_error": "Format error",
+          "no_error": "No error",
+          "non_existent_domain": "Non-existent domain",
+          "not_implemented": "Not implemented",
+          "refused": "Refused",
+          "server_failure": "Server failure"
+        }
+      },
       "last_event": {
         "name": "Last event",
         "state": {

tests/components/gatus/conftest.py

@@ -47,6 +47,7 @@ def mock_gatus_client() -> Generator[AsyncMock]:
                             status=200,
                             duration=23123100,
                             certificate_expiration=7776000000000000,
+                            dns_rcode="NOERROR",
                         )
                     ],
                     events=[Event(type="HEALTHY", timestamp="2026-01-01T00:00:00Z")],

tests/components/gatus/snapshots/test_sensor.ambr

@@ -50,6 +50,56 @@
     'state': '2026-04-01T00:00:00+00:00',
   })
 # ---
+# name: test_sensor_setup_and_states[sensor.core_backend_service_dns_response_code-entry]
+  EntityRegistryEntrySnapshot({
+    'aliases': list([
+      None,
+    ]),
+    'area_id': None,
+    'capabilities': None,
+    'config_entry_id': <ANY>,
+    'config_subentry_id': <ANY>,
+    'device_class': None,
+    'device_id': <ANY>,
+    'disabled_by': None,
+    'domain': 'sensor',
+    'entity_category': <EntityCategory.DIAGNOSTIC: 'diagnostic'>,
+    'entity_id': 'sensor.core_backend_service_dns_response_code',
+    'has_entity_name': True,
+    'hidden_by': None,
+    'icon': None,
+    'id': <ANY>,
+    'labels': set({
+    }),
+    'name': None,
+    'object_id_base': 'DNS response code',
+    'options': dict({
+    }),
+    'original_device_class': None,
+    'original_icon': None,
+    'original_name': 'DNS response code',
+    'platform': 'gatus',
+    'previous_unique_id': None,
+    'suggested_object_id': None,
+    'supported_features': 0,
+    'translation_key': 'dns_rcode',
+    'unique_id': '1234567890abcdef1234567890abcdef_backend_service_dns_rcode',
+    'unit_of_measurement': None,
+  })
+# ---
+# name: test_sensor_setup_and_states[sensor.core_backend_service_dns_response_code-state]
+  StateSnapshot({
+    'attributes': ReadOnlyDict({
+      <EntityStateAttribute.FRIENDLY_NAME: 'friendly_name'>: 'Core Backend Service DNS response code',
+    }),
+    'context': <ANY>,
+    'entity_id': 'sensor.core_backend_service_dns_response_code',
+    'last_changed': <ANY>,
+    'last_reported': <ANY>,
+    'last_updated': <ANY>,
+    'state': 'no_error',
+  })
+# ---
 # name: test_sensor_setup_and_states[sensor.core_backend_service_last_event-entry]
   EntityRegistryEntrySnapshot({
     'aliases': list([

tests/components/gatus/test_sensor.py

@@ -50,6 +50,7 @@ def _to_endpoint_statuses(raw_data: list[dict[str, Any]]) -> list[EndpointStatus
                     status=r.get("status"),
                     duration=r.get("duration"),
                     certificate_expiration=r.get("certificateExpiration"),
+                    dns_rcode=r.get("dnsRcode"),
                 )
                 for r in ep.get("results", [])
             ],
@@ -196,3 +197,31 @@ async def test_sensor_missing_certificate_expiration(
 
     state = hass.states.get("sensor.backend_service_certificate_expiration")
     assert state is None
+
+
+async def test_sensor_missing_dns_rcode(
+    hass: HomeAssistant,
+    mock_gatus_client: AsyncMock,
+    mock_config_entry: MockConfigEntry,
+) -> None:
+    """Test that a result missing DNS rcode creates no entity."""
+    mock_gatus_client.get_endpoints_statuses.return_value = [
+        EndpointStatus(
+            key="backend_service",
+            name="Backend Service",
+            group=None,
+            results=[
+                Result(
+                    success=True,
+                    status=200,
+                    duration=12500000,
+                    dns_rcode=None,
+                )
+            ],
+        )
+    ]
+
+    await setup_integration(hass, mock_config_entry)
+
+    state = hass.states.get("sensor.backend_service_dns_response_code")
+    assert state is None