I found and answer here How should I organize multiple Express servers on the same system? and the best answer was this
express.createServer()
.use(express.vhost('hostname1.com', require('/path/to/hostname1').app)
.use(express.vhost('hostname2.com', require('/path/to/hostname2').app)
.listen(3000)
All ok before there, but how I should organize to handle the request of each site (app) ie myfirstdomain.com => myhost:3000 (=> means proxy) and myseconddomain.com => myhost:3000, well my real question its how I determine which request handles which app, since all request ie / have both of them in their routes.
This its the first app
var app = express.createServer();
app.get('/', function(req, res){
res.send('my first domain');
});
Then this its the second app
var app = express.createServer();
app.get('/', function(req, res){
res.send('my second domain');
});