Get My Web App Base URL in JavaScript

How could I get my web App URL in Node.js? I mean if my site base url is http://localhost:8080/MyApp How could I get it?

Thanks,

You must connect 'url' module

var http = require('http');
var url = require('url') ;

http.createServer(function (req, res) {
  var hostname = req.headers.host; // hostname = 'localhost:8080'
  var pathname = url.parse(req.url).pathname; // pathname = '/MyApp'
  console.log('http://' + hostname + pathname);

  res.writeHead(200);
  res.end();
}).listen(8080);