Java REST API with CI/CD & Traefik Deployment

Overview

This project demonstrates how to design, build, and deploy a production-ready Java REST API with a fully automated CI/CD pipeline and container-based infrastructure, where changes are built, tested, and deployed without manual intervention.

The focus is not only on API implementation, but on the end-to-end delivery lifecycle: clean backend architecture, automated testing, containerization, secure routing, and zero-touch deployment.

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Status & CI/CD

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What This Project Demonstrates

• Clean, layered Java backend architecture (DAO → Service → Controller)
• REST API design with validation and structured error handling
• Automated CI/CD pipeline from Git push to production deployment
• Containerized runtime using Docker and Docker Compose
• Reverse proxy, HTTPS, and routing with Traefik
• Environment-based configuration suitable for real deployments

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Architecture Overview

Developer
   │
   ▼
GitHub Repository
   │
   ▼
GitHub Actions (CI/CD)
   │   - Build & Test
   │   - Build Docker Image
   │   - Push Image
   │   - Deploy via SSH
   ▼
Docker & Docker Compose
   │
   ▼
Traefik (HTTPS & Routing)
   │
   ▼
Java REST API  ──► PostgreSQL

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Repository Structure

src/
├── main/java/
│   ├── controllers/      # HTTP endpoints
│   ├── daos/             # Persistence layer
│   ├── services/         # Business logic
│   ├── exceptions/       # Centralized error handling
│   ├── security/         # Authentication / access control
│   ├── util/             # Shared utilities
│   └── App.java          # Application entrypoint
│
└── test/
    ├── unit/             # Unit tests
    └── integration/      # Integration tests

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CI/CD Pipeline

The pipeline is triggered automatically on pushes to the main branch and performs:

1. Source checkout
2. Build and test execution (mvn package)
3. Docker image build
4. Image push to registry
5. Remote deployment via SSH
6. Zero-downtime restart using Docker Compose

This ensures that every change is tested, packaged, and deployed automatically.

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Deployment Stack

Backend

• Java
• Javalin
• PostgreSQL
• JUnit

DevOps & Infrastructure

• Docker & Docker Compose
• Traefik (reverse proxy & HTTPS)
• GitHub Actions (CI/CD)
• Linux server (cloud VM)

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Local Development

Build and run locally:

mvn clean package
java -jar target/app.jar

Application runs at:

http://localhost:7000

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API Example

GET /api/users

Returns a list of users.

POST /api/users

Creates a new user.

{
  "username": "john",
  "password": "secret"
}

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Error Handling

The API returns structured error responses for predictable client behavior:

{
  "status": "error",
  "message": "User not found",
  "path": "/api/users/999",
  "timestamp": "2025-01-20T10:15:14Z"
}

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Why This Matters

This project reflects how backend services are built and operated in real production environments:

• Automated delivery instead of manual deployments
• Infrastructure-aware backend design
• Secure routing and HTTPS by default

It serves as a practical reference for building and shipping backend services reliably.

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Disclaimer

This project is a demonstration and learning project designed to showcase backend and DevOps practices. While simplified, the patterns and workflows mirror those used in real-world production systems.