Claude Code and Docker: the workflow that keeps containers clean

Docker and Claude Code work well together but there are a few patterns that prevent the common problems: bloated images, broken builds after updates, dev/prod parity issues. Tell Claude about your container setup Add to CLAUDE.md: ## Container setup - Development: docker-compose.yml (run: docker compose up) - Production image: Dockerfile (multi-stage build) - Dev container: .devcontainer/ (VS Code / Claude Code dev container) - Do not modify Dockerfile without running docker build to verify - Test commands run inside container: docker compose exec app [command] Without this, Claude will suggest running commands on the host that should run inside the container, or modify Dockerfiles without verifying the build. The Dockerfile rule that matters most Add explicitly: When modifying Dockerfile: 1. Use multi-stage builds to keep the production image small 2. COPY package.json and lock file separately before running npm install (this preserves Docker layer cache for dependencies) 3. Run as no