NestJS gRPC Microservice with Kafka

A microservice architecture using NestJS, gRPC, and Kafka (in progress).

🛠 Tech Stack

• Node.js: v22
• Package Manager: npm
• Database: MySQL
• Framework: NestJS
• Communication: gRPC
• Message Broker: Kafka (In Progress)

📁 Project Structure

.
├── api-gateway/          # API Gateway Service
├── grpc-user/           # User Microservice
├── shared/              # Shared Resources
│   ├── errors/         # Error Handling
│   └── proto/          # Protocol Buffers
└── docker/             # Docker Configuration

🚀 Getting Started

Prerequisites

• Node.js v22
• MySQL
• npm

Environment Setup

1. Create .env files in both api-gateway and grpc-user directories:

# api-gateway/.env
DB_HOST=localhost
DB_PORT=3306
DB_USERNAME=root
DB_PASSWORD=root
DB_DATABASE=user_db

Installation

# Install dependencies
npm install

Running the Services

# ts compile proto files
npm run pbcompile

# Start User Service
npm run start:user

# Start API Gateway
npm run start:api

🏗 Architecture

Monorepo Structure

• api-gateway: HTTP to gRPC gateway
• grpc-user: User management microservice
• shared: Common resources (protos, errors)

gRPC Communication

• Protocol Buffers for service definitions
• Type-safe communication between services
• Efficient binary protocol

Kafka Integration (In Progress)

• Message broker for event-driven architecture
• Asynchronous communication between services
• Event sourcing and CQRS patterns

📚 API Documentation

Once the services are running, you can access the Swagger documentation at:

http://localhost:3000/api

🔄 Error Handling

The project implements a comprehensive error handling system:

• gRPC to HTTP error mapping
• Consistent error response format
• Detailed error logging

🚧 In Progress

• Kafka integration
• Event-driven architecture
• CQRS implementation
• Additional microservices