docker-development

Docker Development

Smaller images. Faster builds. Secure containers. No guesswork.

Opinionated Docker workflow that turns bloated Dockerfiles into production-grade containers. Covers optimization, multi-stage builds, compose orchestration, and security hardening.

Not a Docker tutorial — a set of concrete decisions about how to build containers that don't waste time, space, or attack surface.

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Slash Commands

Command	What it does
/docker:optimize	Analyze and optimize a Dockerfile for size, speed, and layer caching
/docker:compose	Generate or improve docker-compose.yml with best practices
/docker:security	Audit a Dockerfile or running container for security issues

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When This Skill Activates

Recognize these patterns from the user:

• "Optimize this Dockerfile"
• "My Docker build is slow"
• "Create a docker-compose for this project"
• "Is this Dockerfile secure?"
• "Reduce my Docker image size"
• "Set up multi-stage builds"
• "Docker best practices for [language/framework]"
• Any request involving: Dockerfile, docker-compose, container, image size, build cache, Docker security

If the user has a Dockerfile or wants to containerize something → this skill applies.

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Workflow

/docker:optimize — Dockerfile Optimization

1. Analyze current state

   • Read the Dockerfile
   • Identify base image and its size
   • Count layers (each RUN/COPY/ADD = 1 layer)
   • Check for common anti-patterns

2. Apply optimization checklist

   BASE IMAGE
   ├── Use specific tags, never :latest in production
   ├── Prefer slim/alpine variants (debian-slim > ubuntu > debian)
   ├── Pin digest for reproducibility in CI: image@sha256:...
   └── Match base to runtime needs (don't use python:3.12 for a compiled binary)
   
   LAYER OPTIMIZATION
   ├── Combine related RUN commands with && \
   ├── Order layers: least-changing first (deps before source code)
   ├── Clean package manager cache in the same RUN layer
   ├── Use .dockerignore to exclude unnecessary files
   └── Separate build deps from runtime deps
   
   BUILD CACHE
   ├── COPY dependency files before source code (package.json, requirements.txt, go.mod)
   ├── Install deps in a separate layer from code copy
   ├── Use BuildKit cache mounts: --mount=type=cache,target=/root/.cache
   └── Avoid COPY . . before dependency installation
   
   MULTI-STAGE BUILDS
   ├── Stage 1: build (full SDK, build tools, dev deps)
   ├── Stage 2: runtime (minimal base, only production artifacts)
   ├── COPY --from=builder only what's needed
   └── Final image should have NO build tools, NO source code, NO dev deps