Login Page with React.js, MongoDB: MERN JWT Authentication example

In this tutorial, we will learn how to build a full stack MERN JWT Authentication example: Login & Registration Application with React.js + Node.js Express + MongoDB. The back-end server uses Node.js Express with jsonwebtoken for JWT Authentication & Authorization, Mongoose for interacting with MongoDB database. The front-end will be created with React (with/without Redux), React Router, Axios. We’ll also use Bootstrap and perform Form validation.

Related Post:
React.js + Node.js + Express + MongoDB example: MERN stack CRUD App

Run both projects in one place:
How to integrate React with Node.js Express on same Server/Port

JWT (JSON Web Token)

Comparing with Session-based Authentication that need to store Session on Cookie, the big advantage of Token-based Authentication is that we store the JSON Web Token (JWT) on Client side: Local Storage for Browser, Keychain for IOS and SharedPreferences for Android… So we don’t need to build another backend project that supports Native Apps or an additional Authentication module for Native App users.

There are three important parts of a JWT: Header, Payload, Signature. Together they are combined to a standard structure: header.payload.signature.

The Client typically attaches JWT in x-access-token header:

x-access-token: [header].[payload].[signature]

For more details, you can visit:
In-depth Introduction to JWT-JSON Web Token

React.js Node.js MongoDB Login & Registration example

It will be a full stack MERN Authentication, with Node.js Express for back-end and React.js for front-end. The access is verified by JWT Authentication.

• User can signup new account, login with username & password.
• Authorization by the role of the User (admin, moderator, user)

Let’s see the screenshots of our system:

– Anyone can access a public page before logging in:

– Registration – A new User can signup:

– Form validation will be like this:

– After signup is successful, User can signin on login Page:

– After login, App directs the User to Profile page:

– UI for Authorization login (the navigation bar will change by authorities):

– If a User who doesn’t have Admin role tries to access Admin/Moderator Board page:

Flow for User Registration and User Login

The diagram shows flow of User Registration, User Login and Authorization process.

There are 2 endpoints for authentication:

• api/auth/signup for User Registration
• api/auth/signin for User Login

If Client wants to send request to protected data/endpoints, it add legal JWT to HTTP x-access-token Header.

Back-end with Node.js & MongoDB

Overview

Our Node.js Express Application can be summarized in the diagram below:

Via Express routes, HTTP request that matches a route will be checked by CORS Middleware before coming to Security layer.

Security layer includes:

• JWT Authentication Middleware: verify SignUp, verify token
• Authorization Middleware: check User’s roles with record in MongoDB database

An error message will be sent as HTTP response to Client when the middlewares throw any error, .

Controllers interact with MongoDB Database via Mongoose library and send HTTP response (token, user information, data based on roles…) to Client.

Technology

• Express 4.17.1
• bcryptjs 2.4.3
• jsonwebtoken 8.5.1
• mongoose 5.9.1
• MongoDB

Project Structure

This is directory structure for our Node.js Express & MongoDB application:

– config

• configure MongoDB database connection
• configure Auth Key

– routes

• auth.routes.js: POST signup & signin
• user.routes.js: GET public & protected resources

– middlewares

• verifySignUp.js: check duplicate Username or Email
• authJwt.js: verify Token, check User roles in MongoDB database

– controllers

• auth.controller.js: handle signup & signin actions
• user.controller.js: return public & protected content

– models for Mongoose Models

• user.model.js
• role.model.js

– server.js: import and initialize neccesary modules and routes, listen for connections.

Implementation

You can find step by step to implement this Node.js App in the post:
Node.js + MongoDB: User Authentication & Authorization with JWT

Front-end with React, React Router

Overview

Let’s look at the diagram below.

– The App component is a container with React Router (BrowserRouter). Basing on the state, the navbar can display its items.

– Login & Register components have form for data submission (with support of react-validation library). They call methods from auth.service to make login/register request.

– auth.service methods use axios to make HTTP requests. Its also store or get JWT from Browser Local Storage inside these methods.

– Home component is public for all visitor.

– Profile component displays user information after the login action is successful.

– BoardUser, BoardModerator, BoardAdmin components will be displayed by state user.roles. In these components, we use user.service to access protected resources from Web API.

– user.service uses auth-header() helper function to add JWT to HTTP header. auth-header() returns an object containing the JWT of the currently logged in user from Local Storage.

Technology

We’re gonna use these modules:

• React 16
• react-router-dom 5
• axios 0.19.2
• react-validation 3.0.7
• Bootstrap 4
• validator 12.2.0

Project Structure

This is folders & files structure for this React application:

With the explanation in diagram above, you can understand the project structure easily.

Implementation

You can find step by step to implement this React App in the post:
React JWT Authentication (without Redux) example

Using Hooks:
React Hooks: JWT Authentication (without Redux) example

Or Redux:
React Redux: JWT Authentication & Authorization example

Or Hooks + Redux:
React Hooks + Redux: JWT Authentication & Authorization example

Conclusion

Now we have an overview of MERN Authentication with JWT example by building Registration & Login Page using React.js, MongoDB, Node.js Express.

We also take a look at Node.js Express server architecture using jsonwebtoken & Mongoose, as well as React.js project structure for building a front-end app working with JWT.

Next tutorials will show you more details about how to implement this interesting system:
– Back-end
– Front-end

This React Client also works well with back-end in the post:
– Node.js + MySQL: User Authentication & Authorization with JWT
– Node.js + PostgreSQL: User Authentication & Authorization with JWT

You will want to know how to run both projects in one place:
How to integrate React with Node.js Express on same Server/Port

This Node.js server also works well with front-end in the post:
– React Redux: JWT Authentication & Authorization example
– React Hooks: JWT Authentication (without Redux) example
– React Hooks + Redux: JWT Authentication & Authorization example

Happy learning, see you again!

Further Reading

• https://www.npmjs.com/package/jsonwebtoken
• React Component
• In-depth Introduction to JWT-JSON Web Token