server.js

var http = require('http'),
    WebSocketServer = require('ws').Server,
    express = require('express'),
    port = 1234,
    host = '0.0.0.0';

// create a new HTTP server to deal with low level connection details (tcp connections, sockets, http handshakes, etc.)
var server = http.createServer();

// create a new HTTP framework to deal with high level details (routing, cookies, forms data, etc.)
var app = express();

// create a WebSocket Server on to of the HTTP server to deal with the WebSocket protocol
var wss = new WebSocketServer({
  server: server
});

// Configure the express (the http framework) to serve static files located in the 'public/' folder
app.use(express.static('public'));
server.on('request', app);

// create a function to me able do broadcast messages to all WebSocket connected clients
wss.broadcast = function broadcast(message) {
  wss.clients.forEach(function each(client) {
    client.send(message);
  });
};

// Register a listener for new connections on the WebSocket.
wss.on('connection', function(client) {

  // retrieve the name in the cookies
  var cookies = client.upgradeReq.headers.cookie.split(';');
  var wsname = cookies.find((c) => {
        return c.match(/^\s*wsname/) !== null;
});
  wsname = wsname.split('=')[1];

  // greet the newly connected user
  client.send('Welcome, ' + decodeURIComponent(wsname) + '!');

  // Register a listener on each message of each connection
  client.on('message', function(message) {

    var cli = '[' + decodeURIComponent(wsname) + '] ';
    console.log("message from", cli);
    // when recieving a message, broadcast it to all the connected clients
    wss.broadcast(cli + message);
  });
});


// http sever starts listenning on given host and port.
server.listen(port, host, function() {
  console.log('Listening on ' + server.address().address + ':' + server.address().port);
});