proxy.js

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

function processRequest(req, res, proxy, new_req){
  req.url = new_req.path
  req.headers.host = new_req.host
  res.oldWriteHead = res.writeHead;
  res.writeHead = function(statusCode, headers) {
    res.setHeader('Access-Control-Allow-Origin', '*')
    res.setHeader('Access-Control-Allow-Credentials', true)
    res.oldWriteHead(statusCode, headers);
  }
  try{
    proxy.proxyRequest(req, res, {
      host: req.headers.host.split(":")[0],
      port: parseInt(req.headers.host.split(":")[1]) || 80
    });
  }catch(err){
    console.log(err);
  }
}

httpProxy.createServer(function (req, res, proxy) {
  var url_path = req.url.slice(1)
  if(url_path == "crossdomain.xml"){
    proxy.proxyRequest(req, res, {
      host: '127.0.0.1',
      port: 9000
    });
  }
  else{
    new_req = url.parse(url_path)
    if(new_req.host == "avatars.io"){
      request({
        url: new_req.href,
        followRedirect:false
      }, function(error, response, body){
        var final_req = url.parse(response.headers.location);
        processRequest(req, res, proxy, final_req);
      });
    }
    else{
      if(new_req.host && new_req.host.match(/dgm59|cloudinary|twimg|instagram|facebook|fbcdn|distillery|qrserver|igcdn|naver/)){
        processRequest(req, res, proxy, new_req);
        console.log("allowed " + new_req.host)
      }else{
        console.log("disallowed " + new_req.host)
        res.writeHead(400);
        res.write('Not Allowed');
        res.end();
      }
    }
  }
}).listen(8000);

http.createServer(function (req, res) {
  res.writeHead(200, { 'Content-Type': 'text/xml' });
  res.write('<?xml version="1.0"?>\n<!DOCTYPE cross-domain-policy SYSTEM "http://www.macromedia.com/xml/dtds/cross-domain-policy.dtd">\n<cross-domain-policy>\n<allow-access-from domain="*" />\n</cross-domain-policy>\n');
  res.end();
}).listen(9000);


process.on('uncaughtException', function(e){
  console.log(e)
});