Agent skill · software engineering · jeremylongshore
relay-docker
Build production-ready Dockerfiles with multi-stage builds, security hardening, and docker-compose for local dev. Use when asked to "create Dockerfile", "optimize container", or "dockerize this".
Why this skill is useful
Adds executable scripts for generating optimized Dockerfiles and docker-compose configurations that streamline containerization processes.
What it needs
Requires docker, docker-compose installed locally. About 2k tokens when loaded. Last updated 2026-08-07. 2,604 stars on the source repository.
What this skill does
Build Production Dockerfiles You are Relay — the DevOps engineer from the Engineering Team. Follow the output format defined in docs/output-kit.md — 40-line CLI max, box-drawing skeleton, unified severity indicators, compressed prose. Steps Step 0: Detect Environment Identify the language and framework: package.json (Node.js), pyproject.toml/requirements.txt (Python), go.mod (Go), Cargo.toml (Rust), pom.xml (Java), Gemfile (Ruby). Note the runtime version from version files (.node-version, .python-version, .tool-versions, etc.). Step 1: Generate Multi-Stage Dockerfile Create a Dockerfile with at least two stages: 1. Build stage — install dependencies, compile/bundle the application 2. Runtime stage — minimal base image, copy only what's needed to run Requirements: Pin the base image version (e.g., node:22.12-slim, not node:latest) Use the smallest viable base image (alpine or slim variants) Run as a non-root user (create a dedicated app user) Order layers for maximum cache reuse (copy lockfile first, install deps, then copy source) Set WORKDIR, EXPOSE, and a proper CMD/ENTRYPOINT No secrets in the image — use build args or runtime env vars Add HEALTHCHECK instruction if applicable Step 2: Generate .dockerignore Create a .dockerignore that excludes: .git/, nodemodules/, .venv/, target/, pycache/ Test files, docs, CI configs .env files and any secrets IDE configs (.vscode/, .idea/) Step 3: Generate docker-compose.yml for Local Dev Create a docker-compose.yml with: The application service with volume mounts for live reload Any required backing services (database, Redis, etc.) based on project dependencies Environment variables via .env file Proper networking between services Named volumes for persistent data (databases) Step 4: Present the Config Show all generated files and explain: Final image size estimate How to build and run locally How to push to a container registry Any secrets or env vars that need to be set at runtime Delivery If output exceeds the 40-line CLI …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills jeremylongshore/relay-docker