Spring-Boot-Currency-Converter

A Spring Boot microservice demo for real-time currency conversion This project demonstrates a distributed system with two Spring Boot services:

1. auth-service: Reactive JWT authentication & gRPC server for token validation (Port: 8081 / gRPC: 9091)
2. rate-service: Fetches real-time exchange rates via gRPC server (Port: 8082 / gRPC: 9092)
3. main-service: Edge API Gateway / Transcoder. Translates REST to gRPC (Port: 8080)
4. common-config: Centralized gRPC contracts (.proto) and shared library
5. config-server: Centralized configuration management with encryption (Port: 8888)

Key features include:
✔ Reactive authentication (WebFlux + JWT) ✔ Inter-service communication (High-performance gRPC) ✔ Centralized Contracts (Versioned .proto files in common-config) ✔ Zero-Trust Security (Asynchronous gRPC Auth Interceptors) ✔ Event-driven architecture (Kafka for auth events) ✔ Third-party API integration (ExchangeRate-API) ✔ Resilience Patterns (Circuit breakers, Retries via Resilience4j) ✔ Database persistence (PostgreSQL for transactions, Redis for tokens) ✔ Centralized configuration (Spring Cloud Config) ✔ Observability (Prometheus metrics, Distributed Tracing) ✔ Global exception handling with standardized gRPC error mapping ✔ Containerized deployment (Docker & Kubernetes support)

---

🐳 Docker Deployment

# Build all services

docker-compose build

# Start all services

docker-compose up -d

# View logs

docker-compose logs -f

# Stop all services

docker-compose down

---

🤝 Contributing

1. Create feature branch from master
2. Implement changes with tests (80%+ coverage)
3. Run full test suite: mvn clean verify
4. Submit PR with description

📄 License

Copyright © 2025 Currency Converter Platform

---

📞 Support

• 📧 Email: Chief Backend Engineer or Personal Email

---