Connecting Websockets client to Flask-sockeio server

[Ram-Krushana]

I have created a demo application where I am trying to connect to the client of the WebSockets package.

Client demo code.

    `import asyncio
    import websockets
    import logging
    logger = logging.getLogger('websockets')
    logger.setLevel(logging.INFO)
    logger.addHandler(logging.StreamHandler())
    async def hello():
        async with websockets.connect('ws://localhost:5002') as websocket:
            name = input("What's your name? ")
    
            await websocket.send(name)
            print(f"> {name}")
    
            greeting = await websocket.recv()
            print(f"< {greeting}")
  
  asyncio.get_event_loop().run_until_complete(hello())`

Server demo code.

  `from flask import Flask
  from flask_cors import CORS
  
  from flask_socketio import SocketIO
  
  app = Flask(__name__) 
  CORS(app)
  socketio = \
      SocketIO(
          app,
          logger=True,
          engineio_logger=True,
      )
  
  @app.route('/status', methods=['GET', 'POST'])
  def server_status():
      return "Server is running"
  
  @socketio.on('connect')
  def connect():
      print("Connect Message received:")
  if __name__ == '__main__':
      socketio.run(app, host="0.0.0.0", port=5002)`

There are no logs or error on the server-side. But I am getting connection close errors on client side.

    `Traceback (most recent call last):
      File "/home/pranavdave/work/projects/flask_sockeio_demo/client.py", line 52, in <module>
        asyncio.get_event_loop().run_until_complete(hello())
      File "/usr/lib/python3.8/asyncio/base_events.py", line 616, in run_until_complete
        return future.result()
      File "/home/pranavdave/work/projects/flask_sockeio_demo/client.py", line 49, in hello
        greeting = await websocket.recv()
      File "/home/pranavdave/work/vEnv/py38/innovaccer/lib/python3.8/site-packages/websockets/legacy/protocol.py", line 421, in recv
        await self.ensure_open()
      File "/home/pranavdave/work/vEnv/py38/innovaccer/lib/python3.8/site-packages/websockets/legacy/protocol.py", line 726, in ensure_open
        raise self.connection_closed_exc()
    websockets.exceptions.ConnectionClosedError: code = 1005 (no status code [internal]), no reason
    
    Process finished with exit code 1`

I am using gevent in my flask-sockeio server.

Is my implementation is wrong or did I miss something to set up on server-side?

[miguelgrinberg]

Use a Socket.IO client. A WebSocket client cannot connect to a Socket.IO server. They're different protocols.

[Ram-Krushana]

Thank you for your quick reply.

[tsundokul]

thanks a lot, I've spent two days trying to figure out what's wrong because I've been using a simple WS client