title: express 4.x redirect http to https
body: <p>I have the following code :</p>
  <pre><code>var https        = require('https');
  var http         = require('http');
  var express      = require('express');
  var app          = express();
  var router       = express.Router();
  
  app.use('/', router);
  
  //have 'server' listen for https
  var server = https.createServer(config.sslCredential, app);
  server.listen(config.serverPort);
  
  //listen server on http, and always redirect to https
  var httpServer = http.createServer(function(req,res){
      res.redirect(config.serverDomain+req.url);
  });
  httpServer.listen(config.httpServerPort);
  </code></pre>
  <p>but somehow I can't get the https request to be redirected into https request, how should I do this correctly on node.js with express 4.x ?</p>