Move socket.io setup to module for express 3.x

app.js

var app = express();
var server = require('http').createServer(app);
var io = require('./ioinit')(server);

server.listen(80);

ioinit.js

var io = require('socket.io');

module.exports = function(server) {
  
  io.listen(server);  
  
  // all setup and config goes here
 
  io.sockets.on('connection', function (socket) {
    socket.emit('news', { hello: 'world' });
    socket.on('my other event', function (data) {
      //
    });
  });

  // return the io instance
  return io;

}