docker-containerizationlisted

# Docker Containerization Skill Comprehensive guide for Docker containerization: Dockerfiles, multi-stage builds, Docker Compose orchestration, development environments, and advanced patterns. ## When to Use / Not Use **Use when:** - Writing or optimizing Dockerfiles (multi-stage builds, layer caching, image size) - Setting up Docker Compose for multi-container apps (health checks, volumes, networks) - Creating isolated development environments with worktrees - Configuring DDEV for PHP/TYPO3 projects - Managing ports, browser isolation, and CORS in multi-worktree setups - Running container optimization analysis (`scripts/docker_optimize.py`) **Do NOT use when:** - CI/CD pipeline YAML or pipeline configuration -> use `cicd-pipelines` - Workflow orchestration or release automation -> use `workflow-automation` - Kubernetes or container orchestration platforms -> use cloud-native tooling - Debugging containerized applications -> use `debugging` (but this skill helps with environment setup) ## Decision Tree ``` What Docker task do you need? ├── Write a Dockerfile │ ├── Single-language app, no build step -> Single-stage FROM + COPY + CMD │ ├── Compiled/bundled app (TypeScript, Go, wheel) -> Multi-stage build (build + production) │ ├── Need smallest image -> Alpine or distroless base, multi-stage │ └── PHP/TYPO3 project -> DDEV (see references/ddev-quickstart.md) ├── Set up Docker Compose │ ├── Single app + DB -> 2 services, health check on DB, depends_on with condit