wip invalidate cache when room is finished

src/backend/core/api/viewsets.py

@@ -47,6 +47,8 @@ from core.recording.worker.mediator import (
 
 from . import permissions, serializers
 
+from livekit import api as livekit_api
+
 # pylint: disable=too-many-ancestors
 
 logger = getLogger(__name__)
@@ -347,7 +349,35 @@ class RoomViewSet(
             {"message": f"Recording stopped for room {room.slug}."}
         )
 
-    # todo - support a callback endpoint when a room is finished, to invalidate cached key
+    @decorators.action(
+        detail=False,
+        methods=["post"],
+        url_path="livekit-webhook",
+        permission_classes=[],
+        authentication_classes=[],
+    )
+    def handle_livekit_webhook(self, request, pk=None):  # pylint: disable=unused-argument
+        """Handle LiveKit webhook events."""
+        auth_token = request.headers.get("Authorization")
+        if not auth_token:
+            return drf_response.Response(
+                {"error": "Missing LiveKit authentication token"},
+                status=drf_status.HTTP_401_UNAUTHORIZED
+            )
+
+        token_verifier = livekit_api.TokenVerifier()
+        webhook_receiver = livekit_api.WebhookReceiver(token_verifier)
+
+        webhook_data = webhook_receiver.receive(request.body.decode("utf-8"), auth_token)
+
+        # Todo - livekit triggers a webhook for all events, see if we can restrict webhook to a limited number of events.
+        # Todo - handle Egress stopped / aborted events.
+
+        if webhook_data.event == "room_finished":
+            room_id = webhook_data.room.name
+            utils.clear_cache_passphrase(room_id)
+
+        return drf_response.Response({"message": f"Event processed"})
 
 
 class ResourceAccessListModelMixin:

src/backend/core/utils.py

@@ -28,25 +28,33 @@ def generate_random_passphrase(length=26):
     alphabet = string.ascii_letters + string.digits
     return ''.join(secrets.choice(alphabet) for _ in range(length))
 
-def get_cached_passphrase(room_id):
-    """Get or generate a cached passphrase for a room slug"""
 
+def build_room_passphrase_key(room_id: str) -> str:
+    """Build cache key for room passphrase."""
+    return f"room_passphrase:{room_id}"
+
+def get_cached_passphrase(room_id: str) -> str:
+    """Get or generate encrypted passphrase for a room.
+
+    Retrieves existing passphrase from cache or generates,
+    encrypts and caches a new one if not found.
+    """
     cypher = Fernet(settings.PASSPHRASE_ENCRYPTION_KEY.encode())
-
-    # todo - discuss this hardcoded key prefix
-    encrypted_passphrase = cache.get(f"room_passphrase:{room_id}")
+    cache_key = build_room_passphrase_key(room_id)
+    encrypted_passphrase = cache.get(cache_key)
 
     if encrypted_passphrase is None:
         passphrase = generate_random_passphrase()
         encrypted_passphrase = cypher.encrypt(passphrase.encode()).decode()
-
-        # Store in cache with a timeout (e.g., 24 hours = 86400 seconds)
-        cache.set(f"room_passphrase:{room_id}", encrypted_passphrase, timeout=86400)
-
+        cache.set(cache_key, encrypted_passphrase, timeout=86400)  # 24 hours
         return passphrase
 
     return cypher.decrypt(encrypted_passphrase.encode()).decode()
 
+def clear_room_passphrase(room_id: str) -> None:
+    """Remove room passphrase from cache."""
+    cache.delete(build_room_passphrase_key(room_id))
+
 
 def generate_color(identity: str) -> str:
     """Generates a consistent HSL color based on a given identity string.

src/helm/env.d/dev/values.livekit.yaml.gotmpl

@@ -17,6 +17,10 @@ livekit:
     udp_port: 443
     domain: livekit.127.0.0.1.nip.io
     loadBalancerAnnotations: {}
+  webhook:
+    api_key: devkey
+    urls:
+      - https://meet.127.0.0.1.nip.io/api/v1.0/rooms/livekit-webhook/
 
 
 loadBalancer: