Multi-Stage Dockerfile skill: what it does and how to install it

What it does. Creates Dockerfiles with named dependency, build, test and runtime stages, copying only required artefacts into the final image. It guides base-image selection, cache-friendly layer ordering, .dockerignore, non-root users, permissions, health checks and vulnerability scanning.

When to use it. For containerising applications in any language or framework when the build image should be separated from a minimal runtime image. It also covers reproducible version tags and environment-specific build arguments.