docker-setup

name	docker-setup
description	Generates Dockerfile, docker-compose.yml, and .dockerignore for the project. Auto-detects the stack and creates optimized multi-stage builds with caching, health checks, and dev/prod configurations.
argument-hint	[optional: 'dev', 'prod', or 'both']
allowed-tools	Read, Grep, Glob, Bash, Write

Docker Setup Generator

Detect Stack

!ls package.json requirements.txt pyproject.toml go.mod Cargo.toml *.csproj Gemfile composer.json mix.exs 2>/dev/null !ls Dockerfile docker-compose* .dockerignore 2>/dev/null !cat package.json 2>/dev/null | grep -E '"(main|scripts)"' -A 5 | head -10

---

Generation Process

Step 1: Analyze Requirements

From project files, determine:

• Base image (node:20-alpine, python:3.12-slim, golang:1.22, rust:1.75, etc.)
• Build steps (install deps, compile, bundle)
• Runtime dependencies (only what's needed to run, not to build)
• Port(s) the application listens on
• Required services (database, cache, message queue)
• Environment variables needed

Step 2: Generate Dockerfile

Multi-stage build pattern:

# Stage 1: Dependencies
FROM base AS deps
COPY lock-file .
RUN install-command

# Stage 2: Build
FROM deps AS build
COPY source .
RUN build-command

# Stage 3: Production
FROM base-slim AS production
COPY --from=build /app/dist ./dist
CMD ["start-command"]

Best practices to include:

• Use specific image tags, not latest
• Use .dockerignore to minimize context
• Copy lock files before source (layer caching)
• Run as non-root user
• Set HEALTHCHECK
• Use multi-stage builds to minimize final image size
• Set appropriate EXPOSE port
• Use ENTRYPOINT + CMD pattern

Step 3: Generate docker-compose.yml

services:
  app:
    build: .
    ports: ["3000:3000"]
    environment: ...
    depends_on: ...
    volumes: ...  # for dev: mount source code
    healthcheck: ...

  # Add required services
  db:  # if database detected
  redis:  # if cache detected

Include:

• Development overrides (volume mounts, hot reload)
• Named volumes for persistent data
• Network configuration
• Health checks for all services
• Environment variable references (not hardcoded values)

Step 4: Generate .dockerignore

node_modules/
.git/
dist/
build/
*.log
.env
.env.*

Step 5: Document

Add comments explaining:

• Why each stage exists
• How to build: docker build -t app .
• How to run: docker compose up
• How to access: http://localhost:PORT
• How to run tests in Docker

Rules

• Never hardcode secrets in Dockerfile or docker-compose
• Always use non-root user in production images
• Always include health checks
• Minimize image size (alpine/slim base, multi-stage)
• Include .dockerignore to speed up builds