Spring Boot HelloWorld

A comprehensive Spring Boot application demonstrating modern DevOps practices, functional web programming, and automated CI/CD pipelines with intelligent version management and Podman-based containerization.

🚀 Features Overview

• Spring Boot 3.5.5 with Java 21 (latest LTS)
• Functional web framework with RouterFunction pattern
• Automated CI/CD pipelines with GitHub Actions
• Intelligent version management with automatic SNAPSHOT handling
• Podman-based containerization with security-first approach
• Nexus integration for artifact and container registry management
• Production-ready with comprehensive monitoring and security

📋 Quick Start

Prerequisites

• Java 21
• Maven 3.6+
• Podman or Docker (for containerization)

Local Development

# Clone the repository
git clone https://github.com/adeutschmann/spring-boot-helloworld.git
cd spring-boot-helloworld

# Run the application
./mvnw spring-boot:run

# Test the endpoint
curl http://localhost:8080/hello

Response:

{
  "message": "Hello World"
}

🏗️ Architecture

Project Structure

src/main/java/ch/adeutschmanndev/helloworld/
├── HelloworldApplication.java          # Main Spring Boot application
├── resource/
│   └── HelloWorldHandler.java          # Request handler with business logic
└── router/
    └── HelloWorldRouter.java           # RouterFunction configuration

Design Patterns

• Functional Programming: Uses Spring's RouterFunction instead of traditional @Controller
• Clean Architecture: Separation of concerns with handler and router classes
• 12-Factor App: Cloud-native design principles
• Security-First: Non-root containers and minimal attack surface

📚 Comprehensive Feature Documentation

This project demonstrates multiple enterprise-grade features. Each feature has detailed documentation:

🎯 Core Application Features

• Functional Web Framework - RouterFunction and handler pattern implementation
• Spring Boot Configuration - Modern Spring Boot 3.5.5 with Java 21 setup

🐳 Containerization & Deployment

• Podman Containerization - Security-first, rootless container builds
• Multi-Stage Container Build - Optimized Alpine-based production containers
• Container Deployment Guide - Comprehensive container deployment instructions

🏗️ CI/CD & Automation

• GitHub Actions CI/CD - Automated build, test, and deployment pipelines
• Intelligent Version Management - Automatic SNAPSHOT removal and version incrementing
• Nexus Integration - Artifact and container registry management
• Nexus Setup Guide - Step-by-step GitHub secrets and Nexus configuration

🔧 Development & Operations

• Local Development Setup - IDE integration and debugging
• Testing Strategy - Unit testing and validation approaches

🔒 Security & Best Practices

• Security Implementation - Container security, secrets management, and best practices
• Production Readiness - Monitoring, health checks, and operational considerations

🚀 Deployment Options

Container Deployment

# Using Podman (recommended)
podman pull your-nexus-registry.com:8082/spring-boot-helloworld:latest
podman run -p 8080:8080 your-nexus-registry.com:8082/spring-boot-helloworld:latest

# Using Docker
docker pull your-nexus-registry.com:8082/spring-boot-helloworld:latest
docker run -p 8080:8080 your-nexus-registry.com:8082/spring-boot-helloworld:latest

Local Container Build

# Build with Podman
podman build -t spring-boot-helloworld:latest -f Containerfile .

# Build with Docker
docker build -t spring-boot-helloworld:latest -f Containerfile .

🔄 CI/CD Pipeline

Automated Workflows

• JAR Deployment: Automatic Maven artifact deployment to Nexus
• Container Images: Podman-based builds for linux/amd64 platform
• Version Management: Automatic version incrementing and Git tagging
• Quality Gates: Automated testing and build validation

Container Registry

Container images are automatically built and pushed to Nexus registry:

• Release images: nexus-registry:8082/spring-boot-helloworld:1.0.2
• Latest tag: nexus-registry:8082/spring-boot-helloworld:latest
• Development images: nexus-registry:8082/spring-boot-helloworld:1.0.3-SNAPSHOT-abc12345

🎯 Key Innovations

Zero-Touch Release Management

• Eliminates manual version bumping
• Ensures clean release versions in Nexus (no SNAPSHOT suffixes)
• Maintains development continuity with automatic SNAPSHOT preparation
• Provides complete release traceability through Git tags

Podman-First Container Strategy

• Implements secure, rootless container builds in CI/CD
• Achieves full Docker compatibility without Docker daemon dependency
• Integrates seamlessly with existing Maven and Nexus workflows
• Provides enhanced security through daemon-free architecture

🛠️ Development

IDE Integration

• IntelliJ IDEA: Pre-configured for debug mode
• Comprehensive .gitignore: Excludes .idea, target, and build artifacts
• Maven wrapper: Ensures consistent build environment

Container Features

• Security hardened: Non-root user (UID 1001), minimal Alpine base
• Multi-stage build: Optimized for production deployment
• Health checks: Built-in monitoring and liveness probes
• Resource optimized: Container-aware JVM settings

📊 Monitoring & Operations

• Health endpoint: /hello serves as health check
• Container labels: OCI-compliant metadata for operational insights
• Logging: Comprehensive application logging
• Resource limits: Kubernetes-ready resource constraints

🤝 Contributing

This project demonstrates enterprise-grade patterns and serves as a reference implementation for:

• Modern Spring Boot development practices
• Functional web programming patterns
• DevOps automation with GitHub Actions
• Secure containerization with Podman
• Intelligent release management

📖 Additional Resources

• Nexus Setup Guide - Step-by-step Nexus and GitHub configuration
• Container Deployment Guide - Comprehensive container deployment instructions
• API Documentation - Complete endpoint documentation

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Built with ❤️ using Spring Boot, Java 21, Podman, and modern DevOps practices