Node April Fools Proxy

README.md

April Fools Proxy

A vanilla node proxy that gives webpages a treat.

Clone this gist and simply run node index.js. Then configure 127.0.0.1:8484 as a proxy and you're good to go.

Have fun and be sure to report any pranks!

index.js

var http = require('http'),
    spawn = require('child_process').spawn,
    fs = require('fs'),
    parseUrl = require('url').parse;

// read lolcat.jpg in current directory
var lolcat = fs.readFileSync('lolcat.jpg');

var sendLolcat = function(req, res, pres) {
  /*
   * LOLCATS!!!!!!!!
   */
  pres.headers['content-type'] = 'image/jpg';
  delete pres.headers['content-length'];
  res.writeHead(pres.statusCode, pres.headers);

  var identify = spawn("identify", ['-']);
  identify.stdout.on('data', function(data) {
    var dimensions = data.toString().match(/ (\d+x\d+) /);
    if (dimensions) {
      dimensions = dimensions[1];
      console.log('dimensions', dimensions, 'url', req.url);
      var convert = spawn('convert', ['-', '-resize', '' + dimensions + '\!', 'jpeg:-']);
      convert.stdout.pipe(res);
      convert.stderr.on('data', function(err) {
        console.log('err', err.toString());
      });
      convert.stdin.write(lolcat);
      convert.stdin.end();
    } else {
      res.end();
    }
  });
  pres.pipe(identify.stdin);
};

var rotateAndBlurHtml = function(req, res, pres) {
  console.log('body replace!');
  res.writeHead(pres.statusCode, pres.headers);
  pres.setEncoding('utf-8');
  pres.on('data', function(chunk) {
    // dont do this at home, kids
    chunk = chunk.replace(/<\/body>/, '<script>document.body.style.MozTransform="rotate(-3deg)"; document.body.style.webkitFilter="blur(3px)";</script></body>');
    res.write(chunk);
  });
  pres.on('end', function() {
    res.end();
  });
};

var forwardResponse = function(req, res, pres) {
  res.writeHead(pres.statusCode, pres.headers);
  pres.on('data', function(chunk) {
    res.write(chunk);
  });
  pres.on('end', function() {
    res.end();
  });
};

http.createServer(function(req, res) {
  var u = parseUrl(req.url);
  u.method = req.method;

  // proxy request
  var preq = http.request(u, function(pres) {
    if (pres.headers['content-type'] && pres.headers['content-type'].match(/^image\//)) {
      sendLolcat(req, res, pres);
    } else if (pres.headers['content-type'] && pres.headers['content-type'].match(/^text\/html/)) {
      rotateAndBlurHtml(req, res, pres);
    } else {
      forwardResponse(req, res, pres);
    }
  });
  preq.on('error', function(err) {
    console.log(err);
  });
  preq.end();
}).listen(8484);

lolcat.jpg