Improve Docker Compose setup with environment variables and health checks

[peteralcock]

Summary

This PR significantly improves the Docker Compose configuration and deployment setup for ZEPSEC (RISM) by adding environment variable support, comprehensive health checks, proper service dependencies, and an enhanced entrypoint script. The changes make the application more robust and production-ready.

Key Changes

• Redis Configuration: Updated config/cable.yml to use environment variables (REDIS_HOST and REDIS_PORT) instead of hardcoded localhost values, allowing flexible deployment configurations.

• Docker Compose Restructuring:

  • Upgraded to version 3.8 for better feature support
  • Introduced x-app-common anchor to reduce duplication across app and sidekiq services
  • Reorganized services with clear section comments for better readability
  • Added comprehensive health checks for all services (PostgreSQL, Redis, Rails app, Sidekiq, Nginx)
  • Implemented proper service dependency ordering using condition: service_healthy
  • Enabled Nginx reverse proxy (previously commented out) for production-like setup
  • Improved volume naming (removed rism_ prefix for cleaner organization)
  • Added restart: unless-stopped policy for all services
  • Enhanced Redis configuration with AOF persistence

• Rails Entrypoint Script Enhancement:

  • Added PostgreSQL readiness check with configurable host/port/user via environment variables
  • Implemented automatic database migration/setup on container start
  • Added informative logging for each startup step
  • Improved PID file cleanup with safer rm -f command
  • Changed to exec for proper signal handling

• Documentation: Updated inline comments with clearer quick-start instructions and operational commands.

Notable Implementation Details

• Health checks use appropriate timeouts and retry counts for each service type
• Database migrations run automatically on app startup, eliminating manual setup steps
• Service dependencies ensure proper startup order and readiness before dependent services start
• Environment variable defaults maintain backward compatibility while allowing customization
• Nginx is now enabled by default, providing a production-like reverse proxy setup

https://claude.ai/code/session_01UPcymGmBUdtTd33qSYF24Q