Tutorial: Rate Limiting app in NodeJS

Technical Stack

Frontend: Next.js
Backend - NodeJS, ExpressJS, Redis

How it works

This app has been build using exoress-rate-limit and rate-limit-redis library which will block connections from a client after surpassing certain amount of requests (default: 10) per time (default: 10 sec)

The application will return after each request the following headers. That will let the user know how many requests they have remaining before the run over the limit.

X-RateLimit-Limit: 10
X-RateLimit-Remaining: 9

On the 10th run server should return an HTTP status code of 429 Too Many Requests

Available commands

"PEXPIRE", "MULTI", "DEL", "PTTL", "EXEC", "DECR", "INCR"

Hot to run it locally?

Prerequisites

Node - v12.19.0
NPM - v6.14.8
Docker - v19.03.13 (optional)

Local installation

git clone https://github.com/redis-developer/basic-redis-rate-limiting-demo-nodejs/

# copy file and set proper data inside
cp .env.example .env

# install dependencies
npm install

# run docker compose or install redis manually
docker network create global
docker-compose up -d --build

npm run dev

Env variables:

PORT - port that server is listening on.
REDIS_HOST - host for redis instance. Can be with redis:// or without.
REDIS_PORT - port for redis instance.
REDIS_PASSWORD - password for redis. Running redis by docker-compose, there's no password. Running by https://redislabs.com/try-free/ you have to pass this variable.
REDIS_ENDPOINT_URI - redis port and host encoded in redis uri take precedence over other environment variables. Can be with redis:// or without.
COMPOSE_PROJECT_NAME - only for docker-compose to set project name.

Deployment

To make deploys work, you need to create free account in https://redislabs.com/try-free/ and get Redis' instance informations - REDIS_ENDPOINT_URI and REDIS_PASSWORD. You must pass them as environmental variables (in .env file or by server config, like Heroku Config Variables).

Redis Rate Limiting