containerization

Containerization

When to use

Use when writing Dockerfiles, setting up Docker Compose for local development, deploying to Kubernetes, or evaluating serverless container platforms. Covers image optimization, security hardening, and orchestration patterns.

Core principles

1. Multi-stage builds always — dev dependencies must not reach production
2. Non-root user in production — running as root is a container security violation
3. Layer order matters — most-changing layers last for cache reuse
4. Health checks in every container — orchestrators need them for traffic routing
5. Resource limits are mandatory — unbounded containers destabilize the cluster

References available

• references/dockerfile-patterns.md — Multi-stage builds, layer caching, security scanning, distroless, .dockerignore
• references/kubernetes-patterns.md — Deployment, HPA, resource limits, health checks, RBAC
• references/docker-compose-patterns.md — Local dev, depends_on with healthcheck, volumes, networks
• references/serverless-containers.md — Cloud Run, Fargate, Lambda containers, decision criteria

Scripts available

• scripts/detect-containerization.sh — Checks for Dockerfile, docker-compose.yml, k8s manifests

Assets available

• assets/dockerfile-template — Optimized multi-stage Node.js Dockerfile
• assets/k8s-deployment-template.yaml — Deployment + Service + HPA with best-practice defaults