Node.js Express Login example with PostgreSQL
Tags: node, javascript, webdev, security
Published: 2020-12-28 02:37:11

In this tutorial, we're gonna build a Node.js Express Login & Registration example with PostgreSQL database that supports Token Based Authentication with JWT (JSONWebToken). You'll know:

- Appropriate Flow for User Signup & User Login with JWT Authentication
- Node.js Express Architecture with CORS, Authenticaton & Authorization middlewares & Sequelize
- How to configure Express routes to work with JWT
- How to define Data Models and association for Authentication and Authorization
- Way to use Sequelize to interact with PostgreSQL Database

[For learning only]

Full Article: [https://bezkoder.com/node-js-jwt-authentication-postgresql/](https://bezkoder.com/node-js-jwt-authentication-postgresql/)

## Token Based Authentication
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.

![Alt Text](https://dev-to-uploads.s3.amazonaws.com/i/osy8rwtr9y37vhmlp2za.png)

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 **Authorization** header with Bearer prefix:
```
Authorization: Bearer [header].[payload].[signature]
```
Or only 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](https://bezkoder.com/jwt-json-web-token/)

## Overview of Node.js Express Login & Registration example
We will build a Node.js Express application in that:

- User can signup new account, or login with username & password.
- By User's role (admin, moderator, user), we authorize the User to access resources

This is our Node.js application demo running with MySQL database and test Rest Apis with Postman (logic is the same as using PostgreSQL).

{% youtube fLcxkyMDW08 %}

These are APIs that we need to provide:

- POST 	`/api/auth/signup` 	signup new account
- POST 	`/api/auth/signin` 	login an account
- GET 	`/api/test/all` 	retrieve public content
- GET 	`/api/test/user` 	access User's content
- GET 	`/api/test/mod` 	access Moderator's content
- GET 	`/api/test/admin` 	access Admin's content

## Flow for Signup & Login with JWT Authentication
The diagram shows flow of User Registration, User Login and Authorization process.

![node-js-login-postgresql-example-flow](https://dev-to-uploads.s3.amazonaws.com/i/crv22c186lcj9spryp44.png)

A legal JWT must be added to HTTP **x-access-token** Header if Client accesses protected resources.

You may need to implement Refresh Token like this:

![node-js-express-refresh-token-example-flow](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/wohb3x8su8khbx4mppk5.png)

More details at: [https://bezkoder.com/jwt-refresh-token-node-js/](https://bezkoder.com/jwt-refresh-token-node-js/)

## Node.js Express Architecture with Authentication & Authorization
You can have an overview of our Node.js Express Login & Registration App with PostgreSQL in the diagram below: 

![Alt Text](https://dev-to-uploads.s3.amazonaws.com/i/rjwna60d14npyq7m2h6v.png)

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 database

If these middlewares throw any error, a message will be sent as HTTP response.

**Controllers** interact with PostgreSQL Database via **Sequelize** and send **HTTP response** (token, user information, data based on roles…) to client.

For more details, implementation and Github, please visit:
[https://bezkoder.com/node-js-jwt-authentication-postgresql/](https://bezkoder.com/node-js-jwt-authentication-postgresql/)

**Note**: This tutorial is for learning purpose, better practice is to use HttpOnly cookies.

## Further Reading

- [Node.js Rest APIs example with Express, Sequelize & PostgreSQL](https://bezkoder.com/node-express-sequelize-postgresql/)
- [Node.js + MongoDB: User Authentication & Authorization with JWT](https://bezkoder.com/node-js-mongodb-auth-jwt/)
- [Node.js + MySQL: User Authentication & Authorization with JWT](https://bezkoder.com/node-js-jwt-authentication-mysql/)

Fullstack (JWT Authentication & Authorization example):

- [Node.js Express + Vue.js](https://bezkoder.com/node-express-vue-jwt-auth/)
- [Node.js Express + Angular 8](https://bezkoder.com/node-js-express-angular-jwt-auth/)
- [Node.js Express + Angular 10](https://bezkoder.com/node-js-express-angular-10-jwt-auth/)
- [Node.js Express + Angular 11](https://bezkoder.com/node-js-angular-11-jwt-authentication/)
- [Node.js Express + React](https://bezkoder.com/react-express-authentication-jwt/)

You may need to implement Refresh Token like this:

![node-js-express-refresh-token-example-flow](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/wohb3x8su8khbx4mppk5.png)

More details at: [https://bezkoder.com/jwt-refresh-token-node-js/](https://bezkoder.com/jwt-refresh-token-node-js/)