CI/CD patterns for Terraform: GitHub Actions and GitLab CI examples with OIDC to clouds (avoid long-lived keys), plan-as-PR-comment flows, storing sanitized plan artifacts and gated apply jobs, approval gates for production, scheduled drift detection, and third-party runners (Atlantis, Terraform Cloud/Enterprise, Spacelift, env0). Use when designing pipelines or comparing orchestrators.
Covers how Terraform runs in automation - not individual resources. Pair with terraform-testing
for linters and terraform-security for IAM policies.