WebsocketService: handle clean server disconnection

The websocket async iterator doesn't raise an exception when the server
disconnects cleanly. We should handle that and raise an exception so we can
reconnect.

CHANGELOG.md

@@ -102,6 +102,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Fixed a websocket-based service issue (e.g. `CartesiaTTSService`) that was
+  preventing a reconnection after the server disconnected cleanly, which was
+  causing an inifite loop instead.
+
 - Fixed a `BaseOutputTransport` issue that was causing upstream frames to no be
   pushed upstream.
 

src/pipecat/services/elevenlabs.py

@@ -370,8 +370,13 @@ class ElevenLabsTTSService(WordTTSService, WebsocketService):
         except Exception as e:
             logger.error(f"{self} error closing websocket: {e}")
 
+    def _get_websocket(self):
+        if self._websocket:
+            return self._websocket
+        raise Exception("Websocket not connected")
+
     async def _receive_messages(self):
-        async for message in self._websocket:
+        async for message in self._get_websocket():
             msg = json.loads(message)
             if msg.get("audio"):
                 await self.stop_ttfb_metrics()

src/pipecat/services/websocket_service.py

@@ -10,6 +10,7 @@ from typing import Awaitable, Callable, Optional
 
 import websockets
 from loguru import logger
+from websockets.protocol import State
 
 from pipecat.frames.frames import ErrorFrame
 
@@ -83,11 +84,13 @@ class WebsocketService(ABC):
         while True:
             try:
                 await self._receive_messages()
-                logger.debug(f"{self} connection established successfully")
                 retry_count = 0  # Reset counter on successful message receive
-            except websockets.ConnectionClosed as e:
-                logger.warning(f"{self} connection closed: {e}")
-                break
+                if self._websocket and self._websocket.state == State.CLOSED:
+                    raise websockets.ConnectionClosedOK(
+                        self._websocket.close_rcvd,
+                        self._websocket.close_sent,
+                        self._websocket.close_rcvd_then_sent,
+                    )
             except Exception as e:
                 retry_count += 1
                 if retry_count >= MAX_RETRIES: