julianobarbosa/managing-infra

Infrastructure Patterns

When to Use What

| Tool | Use For | | ------------------ | --------------------------------------------------- | | Raw K8s YAML | Simple deployments, one-off resources | | Kustomize | Environment variations, overlays without templating | | Helm | Complex apps, third-party charts, heavy templating | | Terraform | Cloud resources, infrastructure lifecycle | | GitHub Actions | CI/CD, automated testing, releases | | Makefile | Build automation, self-documenting targets | | Dockerfile | Container builds, multi-stage, multi-arch |

Quick Decisions

Kustomize when: Simple env differences, readable manifests, patching YAML Helm when: Complex templating, third-party charts, release management

K8s Security Defaults

Every workload: non-root user, read-only filesystem, no privilege escalation, dropped capabilities, network policies.

GitHub Actions Patterns

• CI workflow: Lint, test, compile on PRs (run on both x86 + ARM)
• Release workflow: Multi-arch Docker build on tags (native ARM runners)
• Pin actions by SHA, least-privilege permissions

References

• KUBERNETES.md - K8s resource patterns
• TERRAFORM.md - Terraform module patterns
• GITHUB-ACTIONS.md - CI/CD workflow patterns
• MAKEFILE.md - Build automation patterns
• DOCKERFILE.md - Container build patterns
• templates/ - Ready-to-use templates

Commands

kubectl apply -k ./              # Apply kustomize
helm upgrade --install NAME .    # Install/upgrade chart
terraform plan && terraform apply

Gotchas

• Terraform state lock contention: default 10-min lock timeout; bumped timeout doesn't help if the lock holder hung — force-unlock only after confirming the process is dead.
• Helm release name reuse on uninstalled-but-not-purged release fails install with "already exists" — use --no-hooks + explicit purge, or never reuse names.
• Kustomize patches that match nothing silently produce empty diffs — verify with kustomize build after every patch addition.
• Terraform for_each over a computed value forces apply-time count — can cause spurious re-creation of resources between plans.
• helm upgrade --install on a changed values schema can silently drop fields that no longer match — diff the rendered output, not just the values file.
• kubectl apply --server-side vs client-side conflicts when both have been used: client-side last-applied-config can shadow server-side managed fields without error.