Express-Session Undefined [duplicate] - node.js

Question

I am just starting to learn how to use cookies with node and express and I would like some help with getting this to work. I tried to follow the expressjs/session tutorial on GitHub, however I am getting req.session as undefined, so I am unable to set or get any values.
My goal is to save the first and last name of a user to a cookie so that an input field will auto populate. I'm not sure if I need to use cookie-parser as well or if express-session can handle that alone. I'm not sure of how to proceed as I am new to cookies and express-session.
All help is appreciated! Thanks in advance.
Code
let express = require('express');
let app = express();
let credentials = require('../modules/credentials.js');
let session = require('express-session');
let sessionOptions = {
secret: credentials.cookieSecret,
cookie: {
maxAge:269999999999
},
saveUninitialized: true,
resave:true
};
if (app.get('env') === 'production') {
app.set('trust proxy', 1);
sessionOptions.cookie.secure = true;
}
else {
sessionOptions.cookie.secure = false;
}
app.use(session(sessionOptions));
let router = express.Router();
app.use(router);
let request = require('request');
let db = require('../modules/queries');
let bodyParser = require('body-parser');
let cookieParser = require('cookie-parser');
// app.use(cookieParser());
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
router.get('/me', function(req, res, next) {
console.log('req.session: '+req.session);
let firstName = req.session.firstName;
let lastName = req.session.lastName;
if (firstName && lastName) {
res.render('student/me.jade', {firstName, lastName});
}
else {
res.render('student/me.jade', { firstName: '', lastName: ''});
}
});
router.post('/api/me', function(req, res, next) {
let firstName = req.body.firstName;
let lastName = req.body.lastName;
// session.firstName = firstName;
// session.lastName = lastName;
req.session.firstName = firstName;
req.session.lastName = lastName;
console.log('session.firstName: '+session.firstName);
db.addEvent(req, res, next);
});
module.exports = router;

Answer 1

Once you mount a router onto an Express app, any subsequently declared middleware on that app won't get called for any requests that target the router.
So if you have this:
app.use(router)
app.use(session(...));
The session middleware won't get called for any requests that get handled by router (even if you declare the routes that the router should handle at some later point). For that, you need to change the order:
app.use(session(...));
app.use(router);
An additional issue is that you're exporting router, which should probably be app (which is the instance that "holds" all the middleware, routers, etc):
module.exports = app;

Answer 2

To get session data
first , You have to initialize express-session with
app.use(session({ resave: true ,secret: '123456' , saveUninitialized: true}));
then When you want to put something in the session
req.session.firstName = 'Aniruddha';
req.session.lastName = 'Chakraborty';
Then you can check without errors
console.log('req.session: '+req.session.firstName);
Note: This is express-sessions work!

Answer 3

This problem occurred with me while trying to maintain req.session object in my app. I was setting req.session.user in a login route, but was not able to get the same outside that route.
console.log(req.session)
// undefined
Since there was no use of cookie in my app, I removed it.
Before removing cookie variable:
app.use(
session({
resave: false,
saveUninitialized: true,
secret: "anyrandomstring",
cookie: { secure: true},
})
);
After removing cookie variable:
app.use(
session({
resave: false,
saveUninitialized: true,
secret: "anyrandomstring",
})
);
This resolved my issue. And now I was able to access req.session from anywhere in the app.
console.log(req.session)
/* Session{
......
......
}
*/
Note: This issue might also occurs if you have initialized app.use(session({...})) at bottom of the file. Try to bring it to the top.
Why this happens: Click here

Answer 4

You will also see req.session === undefined if your Redis connection is invalid or missing!
I don't see anywhere in your code where connection info is being passed when configuring the session.

Answer 5

Another reason why this might happen is if you're making requests from a different URL. Make sure your app is running on the same URL as your Express back-end.