Express session in nodejs

express_session.js

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

var app = express();

app.use(cookieParser());
//For every request the session id is assigned if there is no session id
//We can attach fields in req.session.key = value pair
app.use(session({ 
    secret: "Shh, its a secret!"
}));

app.get('/', function (req, res) {

    console.log("req sid", req.sessionID)
    console.log('cookies', req.cookies)

    if (req.session.page_views) {
        req.session.page_views++;
        res.send("You visited this page " + req.session.page_views + " times");
    } else {
        req.session.page_views = 1;
        res.send("Welcome to this page for the first time!");
    }
});


app.get('/login', function (req, res) {

    if (req.query.username === 'admin' && req.query.password === 'admin') {
        req.session.username = 'admin';
        req.session.password = 'admin';
        res.send("you are logged in");
    } else {
        res.send("you are not logged in , invalid credencials");
    }

});


app.get('/home', function (req, res) {

    if (req.session.username === 'admin') {
        res.send("welcome to the home page");
    } else {
        res.send("you are not authenticated please login first");
    }

});

app.listen(3000);