Microservices Messaging Assignment

Overview

This repository contains two Node.js microservices that communicate asynchronously via RabbitMQ.

• Microservice A (Sender): Exposes an API endpoint (/send) to accept messages and publish them to a RabbitMQ queue.
• Microservice B (Receiver): Listens to the RabbitMQ queue and processes incoming messages.

Architecture & Design

• Asynchronous Messaging:
  RabbitMQ is used to decouple the sender and receiver, which enhances scalability and fault tolerance.
• Decoupling:
  The services run independently and communicate solely via the message broker, making the system more modular.

Setup Instructions

Prerequisites

• Node.js (v16+)
• Docker (for RabbitMQ)

Setting Up RabbitMQ

Run the following command in the repository root:

docker-compose up -d

This starts RabbitMQ with the AMQP port on 5672 and the management UI on 15672.

Microservice A (Sender)

1. Navigate to the microservice-a directory:

   cd microservice-a

2. Install dependencies:

   npm install

3. Create a .env file (optional) with:

   RABBIT_URL=amqp://localhost
   PORT=3000
   QUEUE=messageQueue
   

4. Start the service:

   npm start

Microservice B (Receiver)

1. Navigate to the microservice-b directory:

   cd microservice-b

2. Install dependencies:

   npm install

3. Create a .env file (optional) with:

   RABBIT_URL=amqp://localhost
   QUEUE=messageQueue
   

4. Start the service:

   npm start

Testing

Microservice A Tests

From the microservice-a directory, run:

npm test

This executes unit tests for the /send endpoint.

Microservice B Tests

From the microservice-b directory, run:

npm test

This runs tests to verify that incoming messages are correctly processed.

Challenges and Resolutions

• Reliable Asynchronous Messaging:
  By ensuring persistent messaging and proper acknowledgment in RabbitMQ, the system can reliably process messages even under load.

• Decoupling Services:
  Using RabbitMQ allows each service to operate independently, easing scalability and maintenance.

• Testing Asynchronous Code:
  We mock the RabbitMQ connection and channels in tests to simulate message delivery without a live broker.

Conclusion

Any fool can write code that a computer can understand 🤖. Good programmers write code that humans can understand💡

Happy coding🚀