Simple NodeJs test script to run it correctly on Koding VMs, the point is using the default address as 0.0.0.0 instead 127.0.0.1

nodetest.js

var http = require('http');
http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('Hello World\n');
}).listen(3000, '0.0.0.0');
console.log('Server running at 3000');