I've hosted a websocket service in my droplet, postman is able to connect to it via ip:port but not my local python app

Hi there,

As you are able to connect with Postman it indicates that the problem is not related to a network problem or a firewall configuration. You are running both Postman and your Python app on the same laptop right?

If this is the case, then it sounds like it might be something to do with your Python app itself, I could suggest testing this out with the following sample app and see if you get the same behaviour:

• Install the websocket library:

pip install websocket-client

• Here’s an example of how you might use it to connect to a WebSocket server:

import websocket
try:
    import thread
except ImportError:
    import _thread as thread
import time

def on_message(ws, message):
    print("Received message: %s" % message)

def on_error(ws, error):
    print("Error occurred: %s" % error)

def on_close(ws):
    print("### closed ###")

def on_open(ws):
    print("Connection opened.")

if __name__ == "__main__":
    websocket.enableTrace(True)
    ws = websocket.WebSocketApp("ws://your-server-ip:3000/ws",
                              on_message = on_message,
                              on_error = on_error,
                              on_close = on_close)
    ws.on_open = on_open
    ws.run_forever()

This script will connect to the WebSocket server at the provided address (ws://your-server-ip:3000/ws). When it receives a message, it will print that message. If an error occurs, it will print the error. When the connection is closed, it will print a closed message. If the connection is successfully opened, it will print an opened message.

You’ll need to replace "ws://your-server-ip:3000/ws" with the address of your WebSocket server.

If you are still getting connection refused, here are some general things that you could check:

1. Check if the service is running: SSH into your droplet and use the netstat command to check if your Go service is running and listening on the expected port:

   sudo netstat -tuln | grep 3000
   

   This should show you something like this if your service is running and listening:

   tcp6       0      0 :::3000                 :::*                    LISTEN
   

   If you don’t see any output, that means your Go service is not running or not listening on port 3000.

2. Check firewall rules: If you’re using UFW on your droplet, you can list the firewall rules with this command:

   ufw status
   

Let me know how it goes!

Best,

Bobby