Avoid creating Prometheus metrics for non-numeric states (#127262)

homeassistant/components/prometheus/__init__.py

@@ -334,8 +334,8 @@ class PrometheusMetrics:
         )
 
     @staticmethod
-    def state_as_number(state: State) -> float:
+    def state_as_number(state: State) -> float | None:
-        """Return a state casted to a float."""
+        """Return state as a float, or None if state cannot be converted."""
         try:
             if state.attributes.get(ATTR_DEVICE_CLASS) == SensorDeviceClass.TIMESTAMP:
                 value = as_timestamp(state.state)
@@ -343,7 +343,7 @@ class PrometheusMetrics:
                 value = state_helper.state_as_number(state)
         except ValueError:
             _LOGGER.debug("Could not convert %s to float", state)
-            value = 0
+            value = None
         return value
 
     @staticmethod
@@ -373,7 +373,7 @@ class PrometheusMetrics:
             prometheus_client.Gauge,
             "State of the binary sensor (0/1)",
         )
-        value = self.state_as_number(state)
+        if (value := self.state_as_number(state)) is not None:
             metric.labels(**self._labels(state)).set(value)
 
     def _handle_input_boolean(self, state: State) -> None:
@@ -382,7 +382,7 @@ class PrometheusMetrics:
             prometheus_client.Gauge,
             "State of the input boolean (0/1)",
         )
-        value = self.state_as_number(state)
+        if (value := self.state_as_number(state)) is not None:
             metric.labels(**self._labels(state)).set(value)
 
     def _numeric_handler(self, state: State, domain: str, title: str) -> None:
@@ -399,8 +399,7 @@ class PrometheusMetrics:
                 f"State of the {title}",
             )
 
-        with suppress(ValueError):
+        if (value := self.state_as_number(state)) is not None:
-            value = self.state_as_number(state)
             if (
                 state.attributes.get(ATTR_UNIT_OF_MEASUREMENT)
                 == UnitOfTemperature.FAHRENHEIT
@@ -422,14 +421,14 @@ class PrometheusMetrics:
             prometheus_client.Gauge,
             "State of the device tracker (0/1)",
         )
-        value = self.state_as_number(state)
+        if (value := self.state_as_number(state)) is not None:
             metric.labels(**self._labels(state)).set(value)
 
     def _handle_person(self, state: State) -> None:
         metric = self._metric(
             "person_state", prometheus_client.Gauge, "State of the person (0/1)"
         )
-        value = self.state_as_number(state)
+        if (value := self.state_as_number(state)) is not None:
             metric.labels(**self._labels(state)).set(value)
 
     def _handle_cover(self, state: State) -> None:
@@ -471,22 +470,18 @@ class PrometheusMetrics:
             "Light brightness percentage (0..100)",
         )
 
-        try:
+        if (value := self.state_as_number(state)) is not None:
             brightness = state.attributes.get(ATTR_BRIGHTNESS)
             if state.state == STATE_ON and brightness is not None:
-                value = brightness / 255.0
+                value = float(brightness) / 255.0
-            else:
-                value = self.state_as_number(state)
             value = value * 100
             metric.labels(**self._labels(state)).set(value)
-        except ValueError:
-            pass
 
     def _handle_lock(self, state: State) -> None:
         metric = self._metric(
             "lock_state", prometheus_client.Gauge, "State of the lock (0/1)"
         )
-        value = self.state_as_number(state)
+        if (value := self.state_as_number(state)) is not None:
             metric.labels(**self._labels(state)).set(value)
 
     def _handle_climate_temp(
@@ -599,11 +594,8 @@ class PrometheusMetrics:
             prometheus_client.Gauge,
             "State of the humidifier (0/1)",
         )
-        try:
+        if (value := self.state_as_number(state)) is not None:
-            value = self.state_as_number(state)
             metric.labels(**self._labels(state)).set(value)
-        except ValueError:
-            pass
 
         current_mode = state.attributes.get(ATTR_MODE)
         available_modes = state.attributes.get(ATTR_AVAILABLE_MODES)
@@ -634,8 +626,7 @@ class PrometheusMetrics:
 
             _metric = self._metric(metric, prometheus_client.Gauge, documentation)
 
-            try:
+            if (value := self.state_as_number(state)) is not None:
-                value = self.state_as_number(state)
                 if (
                     state.attributes.get(ATTR_UNIT_OF_MEASUREMENT)
                     == UnitOfTemperature.FAHRENHEIT
@@ -644,8 +635,6 @@ class PrometheusMetrics:
                         value, UnitOfTemperature.FAHRENHEIT, UnitOfTemperature.CELSIUS
                     )
                 _metric.labels(**self._labels(state)).set(value)
-            except ValueError:
-                pass
 
         self._battery(state)
 
@@ -684,14 +673,9 @@ class PrometheusMetrics:
     @staticmethod
     def _sensor_fallback_metric(state: State, unit: str | None) -> str | None:
         """Get metric from fallback logic for compatibility."""
-        if unit in (None, ""):
+        if unit not in (None, ""):
-            try:
-                state_helper.state_as_number(state)
-            except ValueError:
-                _LOGGER.debug("Unsupported sensor: %s", state.entity_id)
-                return None
-            return "sensor_state"
             return f"sensor_unit_{unit}"
+        return "sensor_state"
 
     @staticmethod
     def _unit_string(unit: str | None) -> str | None:
@@ -713,11 +697,8 @@ class PrometheusMetrics:
             "switch_state", prometheus_client.Gauge, "State of the switch (0/1)"
         )
 
-        try:
+        if (value := self.state_as_number(state)) is not None:
-            value = self.state_as_number(state)
             metric.labels(**self._labels(state)).set(value)
-        except ValueError:
-            pass
 
         self._handle_attributes(state)
 
@@ -726,11 +707,8 @@ class PrometheusMetrics:
             "fan_state", prometheus_client.Gauge, "State of the fan (0/1)"
         )
 
-        try:
+        if (value := self.state_as_number(state)) is not None:
-            value = self.state_as_number(state)
             metric.labels(**self._labels(state)).set(value)
-        except ValueError:
-            pass
 
         fan_speed_percent = state.attributes.get(ATTR_PERCENTAGE)
         if fan_speed_percent is not None:
@@ -796,8 +774,8 @@ class PrometheusMetrics:
             prometheus_client.Gauge,
             "Value of counter entities",
         )
-
+        if (value := self.state_as_number(state)) is not None:
-        metric.labels(**self._labels(state)).set(self.state_as_number(state))
+            metric.labels(**self._labels(state)).set(value)
 
     def _handle_update(self, state: State) -> None:
         metric = self._metric(
@@ -805,7 +783,7 @@ class PrometheusMetrics:
             prometheus_client.Gauge,
             "Update state, indicating if an update is available (0/1)",
         )
-        value = self.state_as_number(state)
+        if (value := self.state_as_number(state)) is not None:
             metric.labels(**self._labels(state)).set(value)
 
     def _handle_alarm_control_panel(self, state: State) -> None:

tests/components/prometheus/test_init.py

@@ -642,7 +642,7 @@ async def test_sensor_without_unit(
         domain="sensor",
         friendly_name="Text Unit",
         entity="sensor.text_unit",
-    ).withValue(0.0).assert_in_metrics(body)
+    ).assert_not_in_metrics(body)
 
 
 @pytest.mark.parametrize("namespace", [""])
@@ -716,6 +716,13 @@ async def test_input_number(
         entity="input_number.target_temperature",
     ).withValue(22.7).assert_in_metrics(body)
 
+    EntityMetric(
+        metric_name="input_number_state_celsius",
+        domain="input_number",
+        friendly_name="Converted temperature",
+        entity="input_number.converted_temperature",
+    ).withValue(100).assert_in_metrics(body)
+
 
 @pytest.mark.parametrize("namespace", [""])
 async def test_number(
@@ -2207,6 +2214,17 @@ async def input_number_fixture(
     set_state_with_entry(hass, input_number_3, 22.7)
     data["input_number_3"] = input_number_3
 
+    input_number_4 = entity_registry.async_get_or_create(
+        domain=input_number.DOMAIN,
+        platform="test",
+        unique_id="input_number_4",
+        suggested_object_id="converted_temperature",
+        original_name="Converted temperature",
+        unit_of_measurement=UnitOfTemperature.FAHRENHEIT,
+    )
+    set_state_with_entry(hass, input_number_4, 212)
+    data["input_number_4"] = input_number_4
+
     await hass.async_block_till_done()
     return data