From 29a6585cb96a6b5792a5a86595876736930e3bb7 Mon Sep 17 00:00:00 2001 From: Affaan Mustafa Date: Thu, 12 Feb 2026 16:14:20 -0800 Subject: [PATCH] feat: add docker-patterns skill for containerized development Docker Compose for local dev, networking, volume strategies, container security hardening, debugging commands, and anti-patterns. Complements the existing deployment-patterns skill which covers CI/CD and production Dockerfiles. Closes #121 --- README.md | 5 +- skills/docker-patterns/SKILL.md | 363 ++++++++++++++++++++++++++++++++ 2 files changed, 366 insertions(+), 2 deletions(-) create mode 100644 skills/docker-patterns/SKILL.md diff --git a/README.md b/README.md index 085adaf6..2fe72eaa 100644 --- a/README.md +++ b/README.md @@ -143,7 +143,7 @@ For manual install instructions see the README in the `rules/` folder. /plugin list everything-claude-code@everything-claude-code ``` -✨ **That's it!** You now have access to 13 agents, 36 skills, and 31 commands. +✨ **That's it!** You now have access to 13 agents, 37 skills, and 31 commands. --- @@ -242,6 +242,7 @@ everything-claude-code/ | |-- database-migrations/ # Migration patterns (Prisma, Drizzle, Django, Go) (NEW) | |-- api-design/ # REST API design, pagination, error responses (NEW) | |-- deployment-patterns/ # CI/CD, Docker, health checks, rollbacks (NEW) +| |-- docker-patterns/ # Docker Compose, networking, volumes, container security (NEW) | |-- e2e-testing/ # Playwright E2E patterns and Page Object Model (NEW) | |-- commands/ # Slash commands for quick execution @@ -799,7 +800,7 @@ The configuration is automatically detected from `.opencode/opencode.json`. |---------|-------------|----------|--------| | Agents | ✅ 13 agents | ✅ 12 agents | **Claude Code leads** | | Commands | ✅ 31 commands | ✅ 24 commands | **Claude Code leads** | -| Skills | ✅ 36 skills | ✅ 16 skills | **Claude Code leads** | +| Skills | ✅ 37 skills | ✅ 16 skills | **Claude Code leads** | | Hooks | ✅ 3 phases | ✅ 20+ events | **OpenCode has more!** | | Rules | ✅ 8 rules | ✅ 8 rules | **Full parity** | | MCP Servers | ✅ Full | ✅ Full | **Full parity** | diff --git a/skills/docker-patterns/SKILL.md b/skills/docker-patterns/SKILL.md new file mode 100644 index 00000000..917c4818 --- /dev/null +++ b/skills/docker-patterns/SKILL.md @@ -0,0 +1,363 @@ +--- +name: docker-patterns +description: Docker and Docker Compose patterns for local development, container security, networking, volume strategies, and multi-service orchestration. +--- + +# Docker Patterns + +Docker and Docker Compose best practices for containerized development. + +## When to Activate + +- Setting up Docker Compose for local development +- Designing multi-container architectures +- Troubleshooting container networking or volume issues +- Reviewing Dockerfiles for security and size +- Migrating from local dev to containerized workflow + +## Docker Compose for Local Development + +### Standard Web App Stack + +```yaml +# docker-compose.yml +services: + app: + build: + context: . + target: dev # Use dev stage of multi-stage Dockerfile + ports: + - "3000:3000" + volumes: + - .:/app # Bind mount for hot reload + - /app/node_modules # Anonymous volume -- preserves container deps + environment: + - DATABASE_URL=postgres://postgres:postgres@db:5432/app_dev + - REDIS_URL=redis://redis:6379/0 + - NODE_ENV=development + depends_on: + db: + condition: service_healthy + redis: + condition: service_started + command: npm run dev + + db: + image: postgres:16-alpine + ports: + - "5432:5432" + environment: + POSTGRES_USER: postgres + POSTGRES_PASSWORD: postgres + POSTGRES_DB: app_dev + volumes: + - pgdata:/var/lib/postgresql/data + - ./scripts/init-db.sql:/docker-entrypoint-initdb.d/init.sql + healthcheck: + test: ["CMD-SHELL", "pg_isready -U postgres"] + interval: 5s + timeout: 3s + retries: 5 + + redis: + image: redis:7-alpine + ports: + - "6379:6379" + volumes: + - redisdata:/data + + mailpit: # Local email testing + image: axllent/mailpit + ports: + - "8025:8025" # Web UI + - "1025:1025" # SMTP + +volumes: + pgdata: + redisdata: +``` + +### Development vs Production Dockerfile + +```dockerfile +# Stage: dependencies +FROM node:22-alpine AS deps +WORKDIR /app +COPY package.json package-lock.json ./ +RUN npm ci + +# Stage: dev (hot reload, debug tools) +FROM node:22-alpine AS dev +WORKDIR /app +COPY --from=deps /app/node_modules ./node_modules +COPY . . +EXPOSE 3000 +CMD ["npm", "run", "dev"] + +# Stage: build +FROM node:22-alpine AS build +WORKDIR /app +COPY --from=deps /app/node_modules ./node_modules +COPY . . +RUN npm run build && npm prune --production + +# Stage: production (minimal image) +FROM node:22-alpine AS production +WORKDIR /app +RUN addgroup -g 1001 -S appgroup && adduser -S appuser -u 1001 +USER appuser +COPY --from=build --chown=appuser:appgroup /app/dist ./dist +COPY --from=build --chown=appuser:appgroup /app/node_modules ./node_modules +COPY --from=build --chown=appuser:appgroup /app/package.json ./ +ENV NODE_ENV=production +EXPOSE 3000 +HEALTHCHECK --interval=30s --timeout=3s CMD wget -qO- http://localhost:3000/health || exit 1 +CMD ["node", "dist/server.js"] +``` + +### Override Files + +```yaml +# docker-compose.override.yml (auto-loaded, dev-only settings) +services: + app: + environment: + - DEBUG=app:* + - LOG_LEVEL=debug + ports: + - "9229:9229" # Node.js debugger + +# docker-compose.prod.yml (explicit for production) +services: + app: + build: + target: production + restart: always + deploy: + resources: + limits: + cpus: "1.0" + memory: 512M +``` + +```bash +# Development (auto-loads override) +docker compose up + +# Production +docker compose -f docker-compose.yml -f docker-compose.prod.yml up -d +``` + +## Networking + +### Service Discovery + +Services in the same Compose network resolve by service name: +``` +# From "app" container: +postgres://postgres:postgres@db:5432/app_dev # "db" resolves to the db container +redis://redis:6379/0 # "redis" resolves to the redis container +``` + +### Custom Networks + +```yaml +services: + frontend: + networks: + - frontend-net + + api: + networks: + - frontend-net + - backend-net + + db: + networks: + - backend-net # Only reachable from api, not frontend + +networks: + frontend-net: + backend-net: +``` + +### Exposing Only What's Needed + +```yaml +services: + db: + ports: + - "127.0.0.1:5432:5432" # Only accessible from host, not network + # Omit ports entirely in production -- accessible only within Docker network +``` + +## Volume Strategies + +```yaml +volumes: + # Named volume: persists across container restarts, managed by Docker + pgdata: + + # Bind mount: maps host directory into container (for development) + # - ./src:/app/src + + # Anonymous volume: preserves container-generated content from bind mount override + # - /app/node_modules +``` + +### Common Patterns + +```yaml +services: + app: + volumes: + - .:/app # Source code (bind mount for hot reload) + - /app/node_modules # Protect container's node_modules from host + - /app/.next # Protect build cache + + db: + volumes: + - pgdata:/var/lib/postgresql/data # Persistent data + - ./scripts/init.sql:/docker-entrypoint-initdb.d/init.sql # Init scripts +``` + +## Container Security + +### Dockerfile Hardening + +```dockerfile +# 1. Use specific tags (never :latest) +FROM node:22.12-alpine3.20 + +# 2. Run as non-root +RUN addgroup -g 1001 -S app && adduser -S app -u 1001 +USER app + +# 3. Drop capabilities (in compose) +# 4. Read-only root filesystem where possible +# 5. No secrets in image layers +``` + +### Compose Security + +```yaml +services: + app: + security_opt: + - no-new-privileges:true + read_only: true + tmpfs: + - /tmp + - /app/.cache + cap_drop: + - ALL + cap_add: + - NET_BIND_SERVICE # Only if binding to ports < 1024 +``` + +### Secret Management + +```yaml +# GOOD: Use environment variables (injected at runtime) +services: + app: + env_file: + - .env # Never commit .env to git + environment: + - API_KEY # Inherits from host environment + +# GOOD: Docker secrets (Swarm mode) +secrets: + db_password: + file: ./secrets/db_password.txt + +services: + db: + secrets: + - db_password + +# BAD: Hardcoded in image +# ENV API_KEY=sk-proj-xxxxx # NEVER DO THIS +``` + +## .dockerignore + +``` +node_modules +.git +.env +.env.* +dist +coverage +*.log +.next +.cache +docker-compose*.yml +Dockerfile* +README.md +tests/ +``` + +## Debugging + +### Common Commands + +```bash +# View logs +docker compose logs -f app # Follow app logs +docker compose logs --tail=50 db # Last 50 lines from db + +# Execute commands in running container +docker compose exec app sh # Shell into app +docker compose exec db psql -U postgres # Connect to postgres + +# Inspect +docker compose ps # Running services +docker compose top # Processes in each container +docker stats # Resource usage + +# Rebuild +docker compose up --build # Rebuild images +docker compose build --no-cache app # Force full rebuild + +# Clean up +docker compose down # Stop and remove containers +docker compose down -v # Also remove volumes (DESTRUCTIVE) +docker system prune # Remove unused images/containers +``` + +### Debugging Network Issues + +```bash +# Check DNS resolution inside container +docker compose exec app nslookup db + +# Check connectivity +docker compose exec app wget -qO- http://api:3000/health + +# Inspect network +docker network ls +docker network inspect _default +``` + +## Anti-Patterns + +``` +# BAD: Using docker compose in production without orchestration +# Use Kubernetes, ECS, or Docker Swarm for production multi-container workloads + +# BAD: Storing data in containers without volumes +# Containers are ephemeral -- all data lost on restart without volumes + +# BAD: Running as root +# Always create and use a non-root user + +# BAD: Using :latest tag +# Pin to specific versions for reproducible builds + +# BAD: One giant container with all services +# Separate concerns: one process per container + +# BAD: Putting secrets in docker-compose.yml +# Use .env files (gitignored) or Docker secrets +```