dockerfile-optimise

name	dockerfile-optimise
description	Dockerfile optimization guidelines from official Docker documentation. This skill should be used when writing, reviewing, or refactoring Dockerfiles to ensure optimal build time, image size, security, and robustness. Triggers on tasks involving Dockerfile creation, Docker image builds, container optimization, multi-stage builds, build cache, or Docker security hardening.

Dockerfile Optimization Best Practices

Comprehensive Dockerfile optimization guide sourced exclusively from official Docker documentation. Contains 48 rules across 8 categories, prioritized by impact to guide automated refactoring and code generation.

When to Apply

Reference these guidelines when:

• Writing new Dockerfiles or modifying existing ones
• Optimizing Docker build times (layer caching, cache mounts, context management)
• Reducing Docker image size (multi-stage builds, minimal base images)
• Hardening container security (secret mounts, non-root users, attestations)
• Setting up CI/CD pipelines with Docker builds
• Reviewing Dockerfiles for anti-patterns

Rule Categories by Priority

Priority	Category	Impact	Prefix
1	Layer Caching & Ordering	CRITICAL	cache-
2	Multi-Stage Builds	CRITICAL	stage-
3	Base Image Selection	HIGH	base-
4	Build Context Management	HIGH	ctx-
5	Security & Secrets	HIGH