server.js

// Require
var url, http, request;
url = require('url');
http = require('http');
request = require('request');

// Don't crash when an error occurs, instead log it
process.on('uncaughtException', function(err){
	console.log(err);
});

// Create our server
var server;
server = http.createServer(function(req,res){
	// Set caching
	res.setHeader('Access-Control-Max-Age', 5*60*1000);  // 5 minutes

	// Set CORS headers
	res.setHeader('Access-Control-Allow-Origin', '*');
	res.setHeader('Access-Control-Request-Method', '*');
	res.setHeader('Access-Control-Allow-Methods', 'OPTIONS, GET');
	res.setHeader('Access-Control-Allow-Headers', '*');
	if ( req.method === 'OPTIONS' ) {
		res.writeHead(200);
		res.end();
		return;
	}

	// Get the params
	var query = url.parse(req.url,true).query;
	var imageUrl = query.url || null;
	var callback = query.callback || null;
	// check for param existance, error if not
	if ( !imageUrl || !callback ) {
		console.log('Missing arguments');
		res.writeHead(400); // 400 = Bad Request
		res.end();
		return;
	}

	// request the image url
	request({
		url: imageUrl,
		method: 'GET',
		encoding: 'base64',
		timeout: 60*1000
	},function(err,imageRes,imageData){
		var responseData, imageContentType;
		if ( !err && imageRes && imageRes.statusCode === 200 ) {
			res.setHeader('Content-Type', 'application/javascript');
			imageContentType = imageRes.headers['content-type'];
			responseData = 'data:'+imageContentType+';base64,'+imageData;
			res.write(callback+'('+JSON.stringify(responseData)+')');
			res.end();
			console.log('Sent image:', imageUrl);
			return;
		}
		else {
			console.log('Failed image:', imageUrl);
			res.writeHead(imageRes && imageRes.statusCode || 400); // bad request
			responseData = JSON.stringify('error:Application error');
			res.write(callback+'('+responseData+')');
			res.end();
			return;
		}
	});
});

// Start our server
server.listen(process.env.WEBSITEPORT || process.env.PORT || 8000, function() {
	var address = server.address();
	console.log("opened server on %j", address);
});

// Export
module.exports = server;