Quick and Dirty Proxy

index.js

var http = require('http'),
    httpProxy = require('http-proxy');

var targetPort = 5555;
var serverPort = 5050;

var proxy = httpProxy.createProxyServer({});

// To modify the proxy connection before data is sent, you can listen
// for the 'proxyReq' event. When the event is fired, you will receive
// the following arguments:
// (http.ClientRequest proxyReq, http.IncomingMessage req,
//  http.ServerResponse res, Object options). This mechanism is useful when
// you need to modify the proxy request before the proxy connection
// is made to the target.
//
proxy.on('proxyReq', function(proxyReq, req, res, options) {
    res.setHeader('X-Special-Proxy-Header', 'foobar');
});

var server = http.createServer(function(req, res) {
    proxy.web(req, res, {
        target: 'http://127.0.0.1:' + targetPort
    });
});

console.log("listening on port " + serverPort);
server.listen(serverPort);

package.json

{
  "name": "Workspace",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "node index.js"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "http-proxy": "^1.11.1"
  }
}