Open app.js and add the following lines before var app = express():

      // ODM With Mongoose 
      var mongoose = require('mongoose'); 
      // Modules to store session 
      var session    = require('express-session'); 
      var MongoStore = require('connect-mongo')(session); 
      // Import Passport and Warning flash modules 
      var passport = require('passport'); 
      var flash = require('connect-flash'); 

This is a simple import process.

Add the following lines after app.set('view engine', 'ejs'):

      // Database configuration 
      var config = require('./server/config/config.js'); 
      // connect to our database 
      mongoose.connect(config.url); 
      // Check if MongoDB is running 
      mongoose.connection.on('error', function() {
        console.error('MongoDB Connection Error. Make sure MongoDB is
         running.'); 
      }); 
 
      // Passport configuration 
      require('./server/config/passport')(passport); 

Note that we are using a config.js file in the first line; later we will create this file.

Add the following lines after app.use(express.static(path.join(__dirname, 'public'))):

      // required for passport 
      // secret for session 
      app.use(session({ 
          secret: 'sometextgohere', 
          saveUninitialized: true, 
          resave: true, 
          //store session on MongoDB using express-session +
          connect mongo 
          store: new MongoStore({ 
              url: config.url, 
              collection : 'sessions' 
          }) 
      })); 
 
      // Init passport authentication 
      app.use(passport.initialize()); 
      // persistent login sessions 
      app.use(passport.session()); 
      // flash messages 
      app.use(flash());