fix: workaround socketio upstream bug when websockets are not available

backend/open_webui/main.py

@@ -812,6 +812,24 @@ async def update_embedding_function(request: Request, call_next):
     return response
 
 
+@app.middleware("http")
+async def inspect_websocket(request: Request, call_next):
+    if (
+        "/ws/socket.io" in request.url.path
+        and request.query_params.get("transport") == "websocket"
+    ):
+        upgrade = (request.headers.get("Upgrade") or "").lower()
+        connection = (request.headers.get("Connection") or "").lower().split(",")
+        # Check that there's the correct headers for an upgrade, else reject the connection
+        # This is to work around this upstream issue: https://github.com/miguelgrinberg/python-engineio/issues/367
+        if upgrade != "websocket" or "upgrade" not in connection:
+            return JSONResponse(
+                status_code=status.HTTP_400_BAD_REQUEST,
+                content={"detail": "Invalid WebSocket upgrade request"},
+            )
+    return await call_next(request)
+
+
 app.mount("/ws", socket_app)
 
 app.mount("/ollama", ollama_app)

src/routes/+layout.svelte

@@ -38,27 +38,20 @@
 	let loaded = false;
 	const BREAKPOINT = 768;
 
-	const setupSocket = (websocket = true) => {
+	const setupSocket = () => {
 		const _socket = io(`${WEBUI_BASE_URL}` || undefined, {
 			reconnection: true,
 			reconnectionDelay: 1000,
 			reconnectionDelayMax: 5000,
 			randomizationFactor: 0.5,
 			path: '/ws/socket.io',
-			auth: { token: localStorage.token },
+			auth: { token: localStorage.token }
-			transports: websocket ? ['websocket'] : ['polling']
 		});
 
 		socket.set(_socket);
 
 		_socket.on('connect_error', (err) => {
-			if (err.message.includes('websocket')) {
-				console.log('WebSocket connection failed, falling back to polling');
-				_socket.close();
-				setupSocket(false);
-			} else {
 			console.log('connect_error', err);
-			}
 		});
 
 		_socket.on('connect', () => {