base64 encoding images using express in NodeJS

dataurlProxy.js

/*
 * node-dataurl-proxy
 * 
 * This code can run in Clound Foundry (http://cloudfoundry.com)
 * You can see example: http://dataurlproxy.cloudfoundry.com/?url=[url]
 */

require.paths.unshift('./node_modules');

var express = require('express'),
              URL = require('url'),
              http = require('http');

var app = module.exports = express.createServer(),
    port = process.env.VMC_APP_PORT || 3000;

// Configuration

app.configure(function(){
  app.use(express.bodyParser());
  app.use(express.methodOverride());
  app.use(app.router);
});

app.configure('development', function(){
  app.use(express.errorHandler({ dumpExceptions: true, showStack: true })); 
});

app.configure('production', function(){
  app.use(express.errorHandler()); 
});

// Routes

app.get('/', function(req, res){
  var url, client, proxyRequest;
  if (req.param('url')) {
    url = URL.parse(req.param('url'));
    
    client = http.createClient(80, url.hostname);
    client.on('error', function(err) {
      res.statusCode = 404;
      res.send(err.message);
    });

    proxyRequest = client.request('GET', url.pathname, { "host": url.hostname });
    proxyRequest.end();

    proxyRequest.on('response', function(proxyResponse) {
      var type = proxyResponse.header('content-type'),
          prefix = 'data:' + type + ';base64,',
          body = '',
          success = true;

      proxyResponse.setEncoding('binary');
      
      proxyResponse.on('data', function(chunk) {
        if (proxyResponse.statusCode === 200) {
	  body += chunk;
        } else {
          res.statusCode = proxyResponse.statusCode;
	  body += chunk;
	  success = false;
        }
      });

      proxyResponse.on('end', function() {
        if (success) {
	  var base64 = new Buffer(body, 'binary').toString('base64'),
	      data = prefix + base64,
	      obj = {
                "src": url.href,
                "data": data
              };

          res.contentType('application/json');
          res.header("Access-Control-Allow-Origin", "*");
          res.header("Access-Control-Allow-Headers", "X-Requested-With");
          res.header("Access-Control-Allow-Methods", "GET,POST");

          res.send(JSON.stringify(obj));
        } else {
          res.send(body);
        }
      });

    });
  }
});

// Only listen on $ node app.js

if (!module.parent) {
  app.listen(port);
  console.log("Express server listening on port %d", app.address().port);
}