feat: Add comprehensive containerization support

[shashax42]

Overview

This issue proposes adding comprehensive containerization support to the Docker Proxy Rule project to modernize the development workflow and enable cloud-native deployment patterns.

Motivation

Currently, the project lacks containerization support, which limits:

• Development environment consistency
• Cloud deployment capabilities
• Monitoring and observability
• CI/CD pipeline efficiency

Proposed Changes

Core Containerization

• Multi-stage Dockerfile with security optimizations
• Docker Compose stack for development environment
• .dockerignore for build optimization

Monitoring & Observability

• Prometheus metrics collection configuration
• Grafana dashboards and data sources
• Health check endpoints for all services

Test Environment

• Nginx test web server configuration
• PostgreSQL test database with initialization scripts
• Redis cache for testing scenarios

CI/CD Enhancements

• Docker build integration in CircleCI
• Container security scanning with Trivy
• Automated container testing

Documentation

• Updated README with container usage instructions
• Development environment setup guide
• Monitoring stack documentation

Technical Details

Docker Features

• Multi-stage build: Gradle build stage + Distroless runtime
• Security: Non-root user, minimal attack surface
• Optimization: Layer caching, build context optimization
• Library Support: Flexible execution for library projects

Monitoring Stack

• Prometheus: Application and JVM metrics collection
• Grafana: Pre-configured dashboards and visualizations
• Health Checks: Kubernetes-ready health endpoints

Development Environment

# Quick start
docker-compose up -d

# Access services
# - Proxy: localhost:1080
# - Test Web Server: localhost:8081  
# - Prometheus: localhost:9090
# - Grafana: localhost:3000 (admin/admin)

Testing Plan

• Docker image builds successfully
• All services start and pass health checks
• Proxy functionality works through containers
• Monitoring stack collects metrics
• CI/CD pipeline builds and scans containers

Benefits

• Developer Experience: Consistent development environment
• Cloud Readiness: Container-native deployment
• Observability: Built-in monitoring and metrics
• Security: Container scanning and hardening
• CI/CD: Automated testing and deployment

Implementation

I have prepared a complete implementation in the feature/containerization branch that includes all the proposed changes. The implementation follows Docker and Kubernetes best practices with security considerations.

Implementation Status

• Dockerfile with multi-stage build
• Docker Compose with full stack
• Monitoring configuration (Prometheus/Grafana)
• Test environment setup
• CI/CD pipeline updates
• Documentation updates
• Security scanning integration
• All comments and documentation in English
• Library project compatibility fixes

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Type (Select exactly one)

• Feature (Adding new functionality)
• Improvement (Improving existing functionality)
• Fix (Fixing an issue with existing functionality)
• Break (Creating a new major version by breaking public APIs)
• Deprecation (Removing functionality in a non-breaking way)
• Migration (Automatically moving data/functionality to a new system)

Description

feat: Add comprehensive containerization support

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