Docker Skill

Docker Skill

Loaded by: DevOps Division agents | Version: 1.0

Dockerfile Pattern

# Multi-stage build
FROM node:20-alpine AS builder
WORKDIR /​app
COPY package*.json ./
RUN npm ci --only=production
COPY . .
RUN npm run build

FROM node:20-alpine AS runtime
WORKDIR /​app
RUN addgroup -g 1001 appgroup && adduser -u 1001 -G appgroup -s /​bin/​sh -D appuser
COPY --from=builder /​app/​dist ./​dist
COPY --from=builder /​app/​node_modules ./​node_modules
USER appuser
EXPOSE 3000
HEALTHCHECK --interval=30s --timeout=3s CMD wget -q --spider http://localhost:3000/health || exit 1
CMD ["node", "dist/​server.js"]

Anti-Patterns

• Do NOT run containers as root
• Do NOT include dev dependencies in production images
• Do NOT hardcode secrets (use env vars or secrets management)
• Do NOT use latest tag in production
• Do NOT skip health checks

Checklist

• Multi-stage build used
• Non-root user configured
• Health check defined
• .dockerignore is comprehensive
• No secrets in image; image size is optimized