Node.js + Redis + MongoDB Sample Project

Overview

This repository demonstrates a simple Node.js application that integrates both Redis and MongoDB. Redis is used as an in-memory cache and temporary storage layer, while MongoDB is available for persistent data storage. The sample includes OTP management, banner storage, and connectivity checks.

Author

• Name: Swapnil Menkar
• Mobile: 8149005578
• LinkedIn: https://www.linkedin.com/in/swapnil-menkar-7051852b/

Project Features

• Express-based REST API
• Redis integration using ioredis
• OTP generation with time-based expiration (TTL)
• Banner storage with Redis key/value operations
• MongoDB connectivity test endpoint
• Docker Compose setup for Redis and MongoDB containers

Redis Usage

Redis is used for high-performance, in-memory key-value operations. The project demonstrates real Redis usage in the following ways:

• otp_with_ttl.js stores OTP codes in Redis with an expiration time using the EX option.
• OTP entries are stored under keys like otp:<phone> and automatically expire after 30 seconds.
• Redis TTL is queried with redis.ttl() to show remaining lifetime of an OTP.
• site_banner.js stores and retrieves application banner text using Redis keys.
• src/index.js includes a /redis endpoint to verify Redis connectivity via PING.

Example Redis commands used

• SET key value EX seconds — store value with TTL
• GET key — retrieve stored value
• DEL key — delete a key after successful verification
• TTL key — check remaining time-to-live
• PING — validate connection status

Getting Started

Prerequisites

• Node.js 18+ installed
• Docker and Docker Compose installed

Install dependencies

npm install

Start services with Docker Compose

docker compose up -d

This starts:

• Redis on localhost:6379
• MongoDB on localhost:27017

Run the application

Use one of the following entry points depending on the feature you want to test:

npm run dev
npm run dev:otp
npm run dev:banner

API Endpoints

Redis health check

• GET /redis
• Returns PING response from Redis.

OTP operations

• POST /otp — generate and store OTP for a phone number
• POST /otp/verify — verify OTP and delete it from Redis
• GET /otp/:phone/ttl — get remaining TTL for the OTP key

Banner management

• POST /banner — save banner text in Redis
• GET /banner — retrieve banner text
• DELETE /banner — delete banner text from Redis
• GET /banner/exists — check whether the banner key exists

MongoDB check

• GET /mongo — connect to MongoDB and report database status

Environment Variables

The application can use these environment variables:

• REDIS_URL — Redis connection string
• MONGO_URL — MongoDB connection string

If not set, the app defaults to local containers:

• redis://localhost:6379
• mongodb://localhost:27017/my_app_database

Notes

• Redis is primarily used for fast, temporary storage and TTL-based data expiration.
• MongoDB is included for persistent storage and connectivity verification.
• The Docker Compose file includes named volumes for Redis and MongoDB data.

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Thanks for using this project, and feel free to connect on LinkedIn for any updates or improvements.