geoip_index.js

var express = require('express');
var mongodb = require('mongodb');
var app = express();
//ENABLE CORS
app.all('*', function(req, res, next) {
  res.header("Access-Control-Allow-Origin", "*");
  res.header("Access-Control-Allow-Headers", "X-Requested-With");
  next();
 });

app.get('/locate', function(req, res) {
	//getting the ip of the client from the request headers or remoteAddress
	var ip = req.param("ip");
	ip = ip || req.headers['x-forwarded-for'] || req.connection.remoteAddress;
	res.end(ip);
});

var server = app.listen(4000, function() {
  console.log('geoip web service listening on port ' + server.address().port);
});