How to integrate Express-rate-limit in Node.js ?

Rate limiting prevents the same IP from making too many requests that will help us prevent attacks like brute force. The express-rate-limit is the npm package for limiting the request from the user.

Project Setup: Run the following sets of commands to create a folder and initialize the project. 

mkdir test-project
cd test-project
npm init -y

Module Installation: Run the following command to install the express and express-rate-limit module:

npm i express express-rate-limit

Project directory: The project structure will look like this:

app.js

// Express is node framework that helps
// in setting up the server and routing.
const express = require("express");

// The express-rate-limit is for
// limiting the incoming request.
const rateLimit = require("express-rate-limit");

// App variable store the express module.
const app = express();

// Creating a limiter by calling rateLimit function with options:
// max contains the maximum number of request and windowMs
// contains the time in millisecond so only max amount of
// request can be made in windowMS time.
const limiter = rateLimit({
    max: 100,
    windowMs: 60 * 60 * 1000,
    message: "Too many request from this IP"
});

// Add the limiter function to the express middleware
// so that every request coming from user passes
// through this middleware.
app.use(limiter);

// GET route to handle the request coming from user
app.get("/", (req, res) => {
    res.status(200).json({
        status: "success",
        message: "Hello from the express server"
    });
});

// Server Setup
const port = 8000;
app.listen(port, () => {
    console.log(`app is running on port ${port}`);
});

Run app.js file using the following command:

node app.js

Output: We will see the following output on the terminal screen.

app is running on http://localhost:8000/

• Output when a request doesn’t exceed the max limit of rate limiter:

  

• Output when a request exceeds the max limit of the rate limiter:

  

The header of the response object has 2 fields X-RateLimit-Limit and X-RateLimit-Remaining which stores the max and remaining request from the user: