alexei-led/managing-infra

Infrastructure Patterns

Safety: Dry-Run Before Apply

NEVER run state-changing commands (kubectl apply, terraform apply, helm upgrade --install) without first presenting the plan/diff to the user.

Always run the read-only equivalent first:

• terraform plan before terraform apply
• kubectl diff before kubectl apply
• helm upgrade --dry-run before helm upgrade

If the user explicitly asks to apply, confirm before executing.

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)
• Terraform CI: include terraform fmt -check, terraform init -backend=false, terraform validate, and terraform plan for changed stacks where credentials allow
• Release workflow: Multi-arch Docker build on tags (native ARM runners)
• Pin actions by SHA, least-privilege permissions

Terraform Module Structure

For shared VPC, service accounts, and app environments:

• Put shared network primitives and organization-wide IAM in shared/foundation modules.
• Put app-specific service accounts, bindings, and deploy-time config in app/environment modules.
• Keep module inputs/outputs explicit; pass IDs, self-links, emails, and subnet names instead of reaching into sibling state implicitly.
• Choose backend/state boundaries deliberately: shared foundations change slowly; app environments can have separate state for safer rollout and ownership.
• Apply least-privilege IAM per service account and environment.
• Require CI validation for changed Terraform stacks: terraform fmt -check, terraform init -backend=false, terraform validate, and terraform plan where credentials allow.

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