node.jstcpwebsocketsocket.iotelnet

Testing node websockets with telnet


I am writing a socket-based server in Node js using the ws library, and I would like to test that my code works. I have seen telnet used elsewhere to test simple chat servers, but when I start my server and execute telnet 127.0.0.1 5000, although the output says "connected to localhost", my server doesn't log anything associated with a new connection. Am I testing my server wrong or is my server simply not working? My server code is below:

    var WebSocketServer = require('ws').Server
      , http = require('http')
      , express = require('express')
      , app = express()
      , port = process.env.PORT || 5000;

    var server = http.createServer(app);
    server.listen(port);

    var wss = new WebSocketServer({server: server});
    console.log('websocket server created');
    wss.on('connection', function(ws) {
    var id = setInterval(function() {
        ws.send(JSON.stringify(new Date()), function() {  });
    }, 1000);

    console.log('websocket connection open');

    ws.on('close', function() {
        console.log('websocket connection close');
        clearInterval(id);
    });
   });

Solution

  • You connected to the HTTP server, but did not establish a WebSocket connection. That's why your script doesn't print anything.

    I'm not sure you can test websockets manually, look at the handshake.

    But there are a few telnet-like programs that work with websocket. Maybe wscat from the ws module you're using will help with that.