Socket IO net::ERR_CONNECTION_REFUSED

I am trying to implement socket.io into my application which is hosted at Azurewebsites. webapp

Here is the server.js

var app = require('express')();
var server = require('http').createServer(app);

server.listen(process.env.PORT || 3001)

app.get('/', function (req, res) {
  res.sendfile(__dirname + '/index.html');
});

var io = require('socket.io')(server);

io.on('connection', function (socket) {
        console.log("Socket connected :"+socket.id);
 socket.emit('news', { hello: 'world' });
});

And Here is the client side socket. index.html

<script src="socket.io/socket.io.js"></script>
            <script>
        var socket = io('http://localhost:3001');
        console.log("scoekt connect",socket)
      socket.on('connect', function(){ console.log('connected to socket'); });
      socket.on('error', function(e){ console.log('error' + e); });

    socket.on( 'news', function( data ){
    console.log("socket data",data);

    });</script>

I am getting the below error

I am not really sure whats is going wrong. Here is the structure of file-ing system

ROOT
app/
index.html
server.js
web.config

PS: this is an Angular2 application

PS: I have checked all the suggested question based on this error but none solved my issue, thus i am posting this question.

Per my experience, Azure Web App doesn't bind loaclhost or 127.0.0.1 to your website, and only ports 80 and 443 are public-facing. This maps to a specific port for your app to listen to, retrievable via process.env.PORT. So you'd need to replace

var socket = io('http://localhost:3001');

with

var socket = io('http://<your app name>.azurewebsites.net');

And if your server side and client side in the different domain, you'd also need to enable CORS on the server side. In Azure, we can enable it with the Azure portal.

In a browser, go to the Azure portal, and navigate to your App Service.
Click CORS in the API menu.
Enter each URL in the empty Allowed Origins text box. A new text box is created. As an alternative, you can enter an asterisk (*) to specify that all origin domains are accepted.
Click Save.

Socket.IO uses WebSockets, which are not enabled by default on Azure. You can also enable WebSocket support using the Azure Portal. Please see the steps below.