♻️(backend) refactor backend recording state management

Instead of relying on the egress_started event—which fires when egress is
starting, not actually started—I now rely on egress_updated for more accurate
status updates. This is especially important for the active status, which
triggers after egress has truly joined the room. Using this avoids prematurely
stopping client-side listening to room.isRecording updates. A further
refactoring may remove reliance on room updates entirely.

The goal is to minimize handling metadata in the mediator class. egress_starting
is still used for simplicity, but egress_started could be considered in the
future.

Note: if the API to start egress hasn’t responded yet, the webhook may fail to
find the recording because it currently matches by worker ID. This is unstable.
A better approach would be to pass the database ID in the egress metadata and
recover the recording from it in the webhook.

Author: lebaudantoine

src/backend/core/recording/services/recording_events.py

@@ -1,7 +1,11 @@
 """Recording-related LiveKit Events Service"""
 
+# pylint: disable=no-member
+
 from logging import getLogger
 
+from livekit import api
+
 from core import models, utils
 
 logger = getLogger(__name__)
@@ -14,6 +18,27 @@ class RecordingEventsError(Exception):
 class RecordingEventsService:
     """Handles recording-related Livekit webhook events."""
 
+    @staticmethod
+    def handle_update(recording, egress_status):
+        """Handle egress status updates and sync recording state to room metadata."""
+
+        room_name = str(recording.room.id)
+
+        status_mapping = {
+            api.EgressStatus.EGRESS_ACTIVE: "started",
+            api.EgressStatus.EGRESS_ENDING: "saving",
+            api.EgressStatus.EGRESS_ABORTED: "aborted",
+        }
+
+        recording_status = status_mapping.get(egress_status)
+        if recording_status:
+            try:
+                utils.update_room_metadata(
+                    room_name, {"recording_status": recording_status}
+                )
+            except utils.MetadataUpdateException as e:
+                logger.exception("Failed to update room's metadata: %s", e)
+
     @staticmethod
     def handle_limit_reached(recording):
         """Stop recording and notify participants when limit is reached."""

src/backend/core/recording/worker/mediator.py

@@ -105,10 +105,4 @@ def stop(self, recording: Recording):
         finally:
             recording.save()
 
-        try:
-            room_name = str(recording.room.id)
-            utils.update_room_metadata(room_name, {"recording_status": "saving"})
-        except utils.MetadataUpdateException as e:
-            logger.exception("Failed to update room's metadata: %s", e)
-
         logger.info("Worker stopped for room %s", recording.room)

src/backend/core/services/livekit_events.py

@@ -138,23 +138,19 @@ def receive(self, request):
         # pylint: disable=not-callable
         handler(data)
 
-    def _handle_egress_started(self, data):
-        """Handle 'egress_started' event."""
+    def _handle_egress_updated(self, data):
+        """Handle 'egress_updated' event."""
 
+        egress_id = data.egress_info.egress_id
         try:
-            recording = models.Recording.objects.get(
-                worker_id=data.egress_info.egress_id
-            )
+            recording = models.Recording.objects.get(worker_id=egress_id)
         except models.Recording.DoesNotExist as err:
             raise ActionFailedError(
-                f"Recording with worker ID {data.egress_info.egress_id} does not exist"
+                f"Recording with worker ID {egress_id} does not exist"
             ) from err
 
-        try:
-            room_name = str(recording.room.id)
-            utils.update_room_metadata(room_name, {"recording_status": "started"})
-        except utils.MetadataUpdateException as e:
-            logger.exception("Failed to update room's metadata: %s", e)
+        egress_status = data.egress_info.status
+        self.recording_events.handle_update(recording, egress_status)
 
     def _handle_egress_ended(self, data):
         """Handle 'egress_ended' event."""

src/backend/core/tests/recording/worker/test_mediator.py

@@ -122,10 +122,7 @@ def test_mediator_start_recording_from_forbidden_status(
     mock_update_room_metadata.assert_not_called()
 
 
-@mock.patch("core.utils.update_room_metadata")
-def test_mediator_stop_recording_success(
-    mock_update_room_metadata, mediator, mock_worker_service
-):
+def test_mediator_stop_recording_success(mediator, mock_worker_service):
     """Test successful recording stop"""
     # Setup
     mock_recording = RecordingFactory(
@@ -143,15 +140,8 @@ def test_mediator_stop_recording_success(
     mock_recording.refresh_from_db()
     assert mock_recording.status == RecordingStatusChoices.STOPPED
 
-    mock_update_room_metadata.assert_called_once_with(
-        str(mock_recording.room.id), {"recording_status": "saving"}
-    )
-
 
-@mock.patch("core.utils.update_room_metadata")
-def test_mediator_stop_recording_aborted(
-    mock_update_room_metadata, mediator, mock_worker_service
-):
+def test_mediator_stop_recording_aborted(mediator, mock_worker_service):
     """Test recording stop when worker returns ABORTED"""
     # Setup
     mock_recording = RecordingFactory(
@@ -166,15 +156,10 @@ def test_mediator_stop_recording_aborted(
     mock_recording.refresh_from_db()
     assert mock_recording.status == RecordingStatusChoices.ABORTED
 
-    mock_update_room_metadata.assert_called_once_with(
-        str(mock_recording.room.id), {"recording_status": "saving"}
-    )
-
 
 @pytest.mark.parametrize("error_class", [WorkerConnectionError, WorkerResponseError])
-@mock.patch("core.utils.update_room_metadata")
 def test_mediator_stop_recording_worker_errors(
-    mock_update_room_metadata, mediator, mock_worker_service, error_class
+    mediator, mock_worker_service, error_class
 ):
     """Test handling of worker errors during stop"""
     # Setup
@@ -190,5 +175,3 @@ def test_mediator_stop_recording_worker_errors(
     # Verify recording updates
     mock_recording.refresh_from_db()
     assert mock_recording.status == RecordingStatusChoices.FAILED_TO_STOP
-
-    mock_update_room_metadata.assert_not_called()

src/backend/core/tests/services/test_livekit_events.py

@@ -94,19 +94,29 @@ def test_handle_egress_ended_success(
     assert recording.status == "stopped"
 
 
+@pytest.mark.parametrize(
+    ("egress_status", "status"),
+    (
+        (EgressStatus.EGRESS_ACTIVE, "started"),
+        (EgressStatus.EGRESS_ENDING, "saving"),
+        (EgressStatus.EGRESS_ABORTED, "aborted"),
+    ),
+)
 @mock.patch("core.utils.update_room_metadata")
-def test_handle_egress_started_success(mock_update_room_metadata, service):
+def test_handle_egress_updated_success(
+    mock_update_room_metadata, egress_status, status, service
+):
     """Should successfully start recording and update room's metadata."""
 
     recording = RecordingFactory(worker_id="worker-1", status="initiated")
     mock_data = mock.MagicMock()
     mock_data.egress_info.egress_id = recording.worker_id
-    mock_data.egress_info.status = EgressStatus.EGRESS_ACTIVE
+    mock_data.egress_info.status = egress_status
 
-    service._handle_egress_started(mock_data)
+    service._handle_egress_updated(mock_data)
 
     mock_update_room_metadata.assert_called_once_with(
-        str(recording.room.id), {"recording_status": "started"}
+        str(recording.room.id), {"recording_status": status}
     )