Docker Development

Patterns for building, testing, and deploying Docker containers.

Core Principles

1. Minimal -- Alpine/distroless, multi-stage
2. Secure -- Non-root USER, no layer secrets, pin versions
3. Testable -- CI-verifiable: entrypoint bypass, DNS mocking
4. Cache-efficient -- deps first, clean in same layer

Quick Reference

Multi-Stage Build (Node.js)

FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./