This answer needs to be updated to work with Express 4.0. Here is how I got the separate http server to work:
var express = require('express');
var http = require('http');
var https = require('https');
// Primary https app
var app = express()
var port = process.env.PORT || 3000;
app.set('env', 'development');
app.set('port', port);
var router = express.Router();
app.use('/', router);
// ... other routes here
var certOpts = {
key: '/path/to/key.pem',
cert: '/path/to/cert.pem'
};
var server = https.createServer(certOpts, app);
server.listen(port, function(){
console.log('Express server listening to port '+port);
});
// Secondary http app
var httpApp = express();
var httpRouter = express.Router();
httpApp.use('*', httpRouter);
httpRouter.get('*', function(req, res){
var host = req.get('Host');
// replace the port in the host
host = host.replace(/:\d+$/, ":"+app.get('port'));
// determine the redirect destination
var destination = ['https://', host, req.url].join('');
return res.redirect(destination);
});
var httpServer = http.createServer(httpApp);
httpServer.listen(8080);