How can we use multiple express session in NodeJS

Ever wonder, like ecommerce website which  has a user functionalities that provides user to place order, change password etc. And after that they also have delivery functionalities  in same server. But mainly ecommerce website microservices to accomplish these functionalities  but what happen when do all these things in same server so we have to main maintain multiple session.

In this explanation, we use passportJs.

In Node.js, Passport.js is a popular authentication middleware that allows you to implement various authentication strategies, such as local, OAuth, OpenID, etc. When working with multiple sessions using Passport.js, you may want to provide different authentication flows for different types of users or applications. Here's how you can achieve this:

1. Install Required Packages:

Ensure you have installed the necessary packages. You'll need at least Express.js and Passport.js:

npm install express passport passport-local express-session

2. Configure Express and Passport:

Set up your Express server and configure Passport with multiple strategies. For this example, we'll use the "Local Strategy" for simplicity, but you can add other strategies as needed.

    
const express = require('express');
    
const passport = require('passport');
    
const LocalStrategy = require('passport-local').Strategy;
    
const session = require('express-session');
    

    
const app = express();
    

    
// Configure Passport with a LocalStrategy
    
passport.use('local-user', new LocalStrategy(
    
  // Your local strategy implementation here
    
));
    


    
passport.use('local-admin', new LocalStrategy(
    
  // Your admin-specific local strategy implementation here
    
));

    


    

      // Serialize and Deserialize user functions (required for session support)
    
    
passport.serializeUser((user, done) => {
    
  done(null, user.id);
    
});
    


    
passport.deserializeUser((id, done) => {
    
  // Fetch user from the database based on the id
    
  // Call done(err, user) with the retrieved user object
    
});
    


    
// Middleware to initialize Passport and Session
    
app.use(session({
    
  secret: 'your-secret-key',
    
  resave: false,
    
  saveUninitialized: false,
    
}));
    


    
app.use(passport.initialize());
    
app.use(passport.session());
    


          

3. Define Different Routes and Authentication Strategies:

Create different routes that use the corresponding authentication strategies. In this example, we have routes for regular users and admin users.

// Route for regular users

 
    

      app.post('/login/user', passport.authenticate('local-user'), (req, res)
      => {
    
    
  // Handle successful authentication for regular users
    
  res.send('User Login Successful');
    
});
    


    
// Route for admin users
    

      app.post('/login/admin', passport.authenticate('local-admin'), (req, res)
      => {
    
    
  // Handle successful authentication for admin users
    
  res.send('Admin Login Successful');
    
});
    

4. Implement User Authentication Functions:

Implement the LocalStrategy's authentication logic for both regular users and admin users.

 
    

      passport.use('local-user', new LocalStrategy((username, password, done)
      => {
    
    
  // Implement authentication logic for regular users
    

      // Call done(err, user) with the retrieved user object if
      authentication is successful
    
    
}));
    


    

      passport.use('local-admin', new LocalStrategy((username, password, done)
      => {
    
    
  // Implement authentication logic for admin users
    

      // Call done(err, user) with the retrieved admin object if
      authentication is successful
    
    
}));
    

5. Protect Routes with Authentication:

Secure the routes that require authentication by adding a middleware that checks if the user is authenticated before allowing access.

    
function ensureAuthenticated(req, res, next) {
    
  if (req.isAuthenticated()) {
    
  return next();
    
  }
    

      res.redirect('/login'); // Redirect to the login page if not
      authenticated
    
    
}
    


    
// Example protected route for regular users
    
app.get('/profile', ensureAuthenticated, (req, res) => {
    
  // Render the profile page for the authenticated user
    
});
     

With the above setup, you now have different authentication strategies for regular users and admin users, allowing you to handle multiple sessions with Passport.js in your Node.js application.