Compartilhar sessões com redis e passaporte em um subdomínio?

connect-redis
express-session
cookie-parser

var express = require('express');
var cookieParser = require('cookie-parser');
var session = require('express-session');
var RedisStore = require('connect-redis')(session);

var app = express();
app.use(cookieParser());
app.use(session({
    secret: "thisismysecretkey",
    store: new RedisStore({ host: 'localhost', port: 6379})
}));

app.get('/', function (req, res) {
  res.send('Hello World!')
})

var server = app.listen(3000, function () {
  var host = server.address().address
  var port = server.address().port
  console.log('Example app listening at http://%s:%s', host, port)
})