RateLimiter

RateLimiter is a simple tool to limit the number of requests to a server from a specific IP address within a defined time window. It helps prevent abuse and overloading of the server.

Features

• Limits the number of requests from an IP address
• Configurable time window and request limit
• Easy to integrate with Node.js HTTP server

Installation

This project does not require any external dependencies and can be run with Node.js.

Usage

1. Copy the Code First, save the following code in a file named rateLimiter.js:

class RateLimiter {
constructor({ windowSizeInSeconds, maxRequests }) {
this.windowSizeInMillis = windowSizeInSeconds * 1000;
this.maxRequests = maxRequests;
this.requests = new Map();
}

    isAllowed(ip) {
        const currentTime = Date.now();
        if (!this.requests.has(ip)) {
            this.requests.set(ip, []);
        }

        const requestTimes = this.requests.get(ip);
        // Remove outdated request timestamps
        while (requestTimes.length > 0 && requestTimes[0] <= currentTime - this.windowSizeInMillis) {
            requestTimes.shift();
        }

        if (requestTimes.length < this.maxRequests) {
            requestTimes.push(currentTime);
            return true;
        } else {
            return false;
        }
    }

    handleRequest(req, res, next) {
        const ip = req.connection.remoteAddress || req.socket.remoteAddress;
        if (this.isAllowed(ip)) {
            next();
        } else {
            res.writeHead(429, { 'Content-Type': 'text/plain' });
            res.end('Too Many Requests');
        }
    }
}

// Usage Example with Node.js HTTP server

const http = require('http');
const rateLimiter = new RateLimiter({ windowSizeInSeconds: 60, maxRequests: 10 });

http.createServer((req, res) => {
rateLimiter.handleRequest(req, res, () => {
res.writeHead(200, { 'Content-Type': 'text/plain' });
res.end('Request allowed');
});
}).listen(3000, () => {
console.log('Server running at http://localhost:3000');
});

2. Run the Server To start the server, run the following command in your terminal:

node rateLimiter.js
The server will run on port 3000, and you can access it in your browser at http://localhost:3000.

Adding New Routes

To add new routes and handlers, modify the example server code. Simply add new routes and their corresponding handlers to the server's request handling logic.

Method Descriptions

isAllowed(ip): Checks if a request from the given IP address is allowed based on the rate limit. handleRequest(req, res, next): Middleware function to handle incoming requests, checking the rate limit and either allowing the request or returning a "Too Many Requests" response.