mrsingh-rishi/notification-system

Notification System

A scalable notification system built with Node.js and Express, utilizing Kafka for message handling and microservices architecture. The backend API pushes notification data to Kafka, which is then processed by dedicated consumers for email, SMS, and WhatsApp notifications.

Images

Architecture Diagram

Figure 1: Overview of the notification system architecture.

Features

• Microservices Architecture: Ensures modularity and scalability.
• Unified API Endpoint: Send notifications via email, SMS, or WhatsApp using a single API.
• Kafka Integration: Manages and routes notification messages asynchronously.
• Dedicated Consumers: Separate consumers handle email, SMS, and WhatsApp notifications.

Technologies

• Node.js: JavaScript runtime for server-side applications.
• Express: Web framework for API development.
• Kafka: Distributed streaming platform for managing messages.
• Brevo: Service provider for email notifications.
• Tailliwo: Service provider for SMS and WhatsApp messaging.

Architecture

1. Backend API: Exposes a single endpoint to receive notification requests and pushes notification data to Kafka.
2. Kafka: Handles asynchronous message processing and routing.
3. Consumers: Dedicated services for processing notifications:
   • Email Consumer: Sends notifications via Brevo.
   • SMS Consumer: Sends notifications via Tailliwo.
   • WhatsApp Consumer: Sends notifications via Tailliwo.

Getting Started

Prerequisites

• Node.js (v14.x or higher)
• Kafka (for local development or a Kafka cluster)
• Brevo and Tailliwo accounts

Installation

Method 1: Manual Installation

1. Clone the repository:

   git clone https://github.com/mrsingh-rishi/notification-system.git
   cd notification-system

2. Install dependencies:

   cd api
   npm install
   cd ..
   cd email-consumer
   npm install
   cd ..
   cd whatsapp-consumer
   npm install
   cd ..
   cd sms-consumer
   npm install
   cd ..

3. Configuration:

   Rename the .env.example file in email-consumer, sms-consumer, and whatsapp-consumer to .env and update the necessary environment variables.

4. Start Kafka:

   Ensure Kafka is running on your local machine or use a Kafka cluster. For local development, follow the Kafka Quickstart.

5. Run the Prisma Migrate and Generate Commands:

   npm run prisma:migrate
   npm run prisma:generate

6. Run the Backend API:

   npm start

7. Seed the DB

   npm run seed

8. Run Consumers:

   Start each consumer to process notifications from Kafka:

   cd email-consumer && npm run start
   cd sms-consumer && npm run start
   cd whatsapp-consumer && npm run start

Method 2: Docker Installation

1. Build Docker Images:

   docker-compose build

2. Start the Application:

   docker-compose up

   This will start the backend API, email consumer, SMS consumer, WhatsApp consumer, and Kafka services. Ensure you have Docker installed on your system.

API Endpoint

Send Notification

• Endpoint: /api/notifications
• Method: POST
• Description: Sends a notification via the specified service (email, SMS, or WhatsApp).
• Request Body:

  {
    "userId": 1,
    "message": "Your notification message here"
  }