Generates production-ready Dockerfiles with multi-stage builds, layer caching, security hardening (non-root users, minimal base images), health checks, and automatic .dockerignore creation. Validates output using devops-skills:dockerfile-validator with iterative error fixing. Use when a user wants to create, generate, write, or build a Dockerfile or docker image, containerize an app, set up a container, or needs a Dockerfile for Node.js, Python, Go, Java, or another language. Also applies when the user says 'containerize my app', 'docker-compose setup', 'container setup', or 'optimize my Docker build'.