Java Spring Microservices Monorepo

A comprehensive monorepo for a cloud-native microservices architecture built with Java, Spring Boot, Docker, and AWS emulation via LocalStack.

---

Table of Contents

• Overview
• Modules
• Tech Stack
• Getting Started
• Environment Variables
• Running Locally
• Testing
• API Requests & Integration Tests
• Project Structure
• Contributing
• License

---

Overview

This project demonstrates best practices for designing, developing, and deploying distributed systems using modern Java technologies. It includes multiple microservices, an API Gateway, infrastructure-as-code with AWS CDK (Java), and local AWS cloud emulation with LocalStack.

---

Modules

• api-gateway: Central entry point for all client requests, routes to services.
• auth-service: Handles authentication, JWT, and user management.
• patient-service: Manages patient data and operations.
• billing-service: Handles billing, payments, and invoicing.
• analytics-service: Processes analytics events (via Kafka/MSK).
• infra: Infrastructure as code (AWS CDK in Java).
• integration-tests: Automated integration tests.
• api-requests: Example API requests (Postman, HTTP files, etc.).
• grpc-requests: Example gRPC requests.

---

Tech Stack

• Java 17+ (Spring Boot)
• Docker & Docker Compose
• AWS CDK (Java)
• LocalStack (AWS emulation)
• PostgreSQL (RDS emulation)
• Apache Kafka (MSK emulation)
• gRPC
• Maven

---

Getting Started

Prerequisites

• Java 17 or higher
• Maven
• Docker
• LocalStack
• (Optional) Postman or HTTP client

Clone the Repository

git clone https://github.com/<your-username>/<your-repo>.git
cd java-spring-microservices-main

---

Environment Variables

Each service uses environment variables for configuration.
You can set these in your IDE, Docker Compose, or as system env vars.

Common Variables

Variable	Description	Example Value
SPRING_DATASOURCE_URL	JDBC URL for Postgres DB	jdbc:postgresql://localhost:5432/db
SPRING_DATASOURCE_USERNAME	DB username	admin_user
SPRING_DATASOURCE_PASSWORD	DB password	password
SPRING_JPA_HIBERNATE_DDL_AUTO	Hibernate DDL mode	update
SPRING_SQL_INIT_MODE	SQL init mode	always
SPRING_KAFKA_BOOTSTRAP_SERVERS	Kafka/MSK bootstrap servers	localhost:9092
JWT_SECRET	JWT signing secret (Auth Service)	your-secret-key
BILLING_SERVICE_ADDRESS	Billing service address (Patient Service)	billing-service
BILLING_SERVICE_GRPC_PORT	Billing gRPC port (Patient Service)	9001

Example for auth-service:

SPRING_DATASOURCE_URL=jdbc:postgresql://auth-service-db:5432/auth-service-db
SPRING_DATASOURCE_USERNAME=admin_user
SPRING_DATASOURCE_PASSWORD=password
SPRING_JPA_HIBERNATE_DDL_AUTO=update
SPRING_SQL_INIT_MODE=always
JWT_SECRET=your-secret-key

Example for patient-service:

SPRING_DATASOURCE_URL=jdbc:postgresql://patient-service-db:5432/patient-service-db
SPRING_DATASOURCE_USERNAME=admin_user
SPRING_DATASOURCE_PASSWORD=password
SPRING_JPA_HIBERNATE_DDL_AUTO=update
SPRING_SQL_INIT_MODE=always
SPRING_KAFKA_BOOTSTRAP_SERVERS=kafka:9092
BILLING_SERVICE_ADDRESS=billing-service
BILLING_SERVICE_GRPC_PORT=9001

---

Running Locally

1. Start LocalStack

docker run -d --name localaws -p 4566:4566 -p 4510-4520:4510-4520 localstack/localstack:latest

2. Build Infrastructure

cd infra
mvn clean compile
./localstack-deploy.sh

3. Build and Run Services

You can use Docker Compose, or run each service with Maven:

cd auth-service
mvn spring-boot:run
# Repeat for other services

Or build Docker images and run with Docker Compose (if provided).

---

Testing

• Unit tests:
  Each service contains its own unit tests. Run with:

  mvn test

• Integration tests:
  Run from the integration-tests module:

  cd integration-tests
  mvn test

---

API Requests & Integration Tests

• Use the files in api-requests/ for example HTTP requests (Postman, .http, etc.).
• Use the files in grpc-requests/ for gRPC testing.

---

Project Structure

java-spring-microservices-main/
│
├── api-gateway/           # API Gateway service
├── auth-service/          # Auth service
├── patient-service/       # Patient service
├── billing-service/       # Billing service
├── analytics-service/     # Analytics service
├── infra/                 # Infrastructure as code (CDK)
├── integration-tests/     # Integration tests
├── api-requests/          # Example API requests
├── grpc-requests/         # Example gRPC requests
├── .gitignore
├── README.md
└── ...

---

Contributing

Contributions are welcome! Please open issues or pull requests for improvements, bug fixes, or new features.

---

License

This project is licensed under the MIT License. See LICENSE for details.

---

Feel free to customize this README for your specific project, add more details, or ask for a version tailored to your needs!