Register per-camera notifications MQTT callbacks (#23637)

* fix per-camera notification MQTT topics never being registered

register notifications/set and notifications/suspend callbacks for each camera, and gate the global notifications topics on per-camera config as well as global (matching WebPushClient creation in app.py). Unregistered topics were silently dropped by paho since only registered callbacks receive messages.

* add tests

frigate/comms/mqtt.py

@@ -41,6 +41,18 @@ class MqttClient(Communicator):
         self.publish("available", "stopped", retain=True)
         self.client.disconnect()
 
+    def _notifications_enabled_in_config(self) -> bool:
+        """Whether notifications are configured globally or on any camera.
+
+        Notifications can be enabled per camera with the global config left
+        disabled, so the global topics must consider both (matching how
+        app.py decides to create the WebPushClient).
+        """
+        return self.config.notifications.enabled_in_config or any(
+            cam.enabled and cam.notifications.enabled_in_config
+            for cam in self.config.cameras.values()
+        )
+
     def _set_initial_topics(self) -> None:
         """Set initial state topics."""
         for camera_name, camera in self.config.cameras.items():
@@ -157,7 +169,7 @@ class MqttClient(Communicator):
                     retain=True,
                 )
 
-        if self.config.notifications.enabled_in_config:
+        if self._notifications_enabled_in_config():
             self.publish(
                 "notifications/state",
                 "ON" if self.config.notifications.enabled else "OFF",
@@ -256,6 +268,7 @@ class MqttClient(Communicator):
             "review_detections",
             "object_descriptions",
             "review_descriptions",
+            "notifications",
         ]
 
         for name in self.config.cameras.keys():
@@ -265,6 +278,12 @@ class MqttClient(Communicator):
                     self.on_mqtt_command,
                 )
 
+            # notifications suspend doesn't follow the /set topic pattern
+            self.client.message_callback_add(
+                f"{self.mqtt_config.topic_prefix}/{name}/notifications/suspend",
+                self.on_mqtt_command,
+            )
+
             if self.config.cameras[name].onvif.host:
                 self.client.message_callback_add(
                     f"{self.mqtt_config.topic_prefix}/{name}/ptz",
@@ -289,7 +308,7 @@ class MqttClient(Communicator):
                     self.on_mqtt_command,
                 )
 
-        if self.config.notifications.enabled_in_config:
+        if self._notifications_enabled_in_config():
             self.client.message_callback_add(
                 f"{self.mqtt_config.topic_prefix}/notifications/set",
                 self.on_mqtt_command,

frigate/test/test_mqtt_topic_registration.py

@@ -0,0 +1,100 @@
+"""Tests for MQTT command topic callback registration."""
+
+import unittest
+from unittest.mock import MagicMock, patch
+
+from frigate.comms.mqtt import MqttClient
+
+
+def _make_camera_mock(
+    *,
+    enabled: bool = True,
+    notifications_enabled_in_config: bool = False,
+) -> MagicMock:
+    """Build a camera config mock with the fields _start() reads."""
+    camera = MagicMock()
+    camera.enabled = enabled
+    camera.notifications.enabled_in_config = notifications_enabled_in_config
+    camera.onvif.host = None
+    camera.motion.mask = {}
+    camera.objects.mask = {}
+    camera.zones = {}
+    return camera
+
+
+def _registered_topics(
+    cameras: dict[str, MagicMock],
+    *,
+    global_notifications_enabled_in_config: bool = False,
+) -> set[str]:
+    """Start an MqttClient against a mocked paho client and collect the
+    topics registered via message_callback_add."""
+    config = MagicMock()
+    config.cameras = cameras
+    config.notifications.enabled_in_config = global_notifications_enabled_in_config
+    config.mqtt.topic_prefix = "frigate"
+    config.mqtt.client_id = "frigate"
+    config.mqtt.user = None
+    config.mqtt.tls_ca_certs = None
+    config.mqtt.tls_insecure = None
+
+    with patch("frigate.comms.mqtt.mqtt.Client") as client_cls:
+        mqtt_client = MqttClient(config)
+        mqtt_client.subscribe(MagicMock())
+
+    paho_client = client_cls.return_value
+    return {call.args[0] for call in paho_client.message_callback_add.call_args_list}
+
+
+class TestMqttTopicRegistration(unittest.TestCase):
+    def test_camera_notification_topics_registered(self):
+        """Per-camera notification set/suspend must be registered so paho
+        routes them to the dispatcher (unregistered topics drop silently)."""
+        topics = _registered_topics(
+            {"front_door": _make_camera_mock(notifications_enabled_in_config=True)}
+        )
+
+        self.assertIn("frigate/front_door/notifications/set", topics)
+        self.assertIn("frigate/front_door/notifications/suspend", topics)
+
+    def test_global_set_registered_with_camera_only_notifications(self):
+        """The global topic must work when notifications are enabled only at
+        the camera level, matching the WebPushClient gating in app.py."""
+        topics = _registered_topics(
+            {"front_door": _make_camera_mock(notifications_enabled_in_config=True)},
+            global_notifications_enabled_in_config=False,
+        )
+
+        self.assertIn("frigate/notifications/set", topics)
+
+    def test_global_set_registered_with_global_notifications(self):
+        topics = _registered_topics(
+            {"front_door": _make_camera_mock()},
+            global_notifications_enabled_in_config=True,
+        )
+
+        self.assertIn("frigate/notifications/set", topics)
+
+    def test_global_set_not_registered_when_notifications_unconfigured(self):
+        topics = _registered_topics(
+            {"front_door": _make_camera_mock()},
+            global_notifications_enabled_in_config=False,
+        )
+
+        self.assertNotIn("frigate/notifications/set", topics)
+
+    def test_disabled_camera_does_not_enable_global_set(self):
+        topics = _registered_topics(
+            {
+                "front_door": _make_camera_mock(
+                    enabled=False, notifications_enabled_in_config=True
+                )
+            },
+            global_notifications_enabled_in_config=False,
+        )
+
+        self.assertNotIn("frigate/notifications/set", topics)
+
+
+if __name__ == "__main__":
+    unittest.main()