Rego domain reference

rules.md covers language-wide style and correctness rules. This skill indexes deeper, domain-specific reference material — worked examples and patterns for particular OPA use cases. Read the file for the domain you're working in before writing policy code in that area.

Domains

• Kubernetes admission control — webhook policies and OPA Gatekeeper ConstraintTemplate policies. Image registry validation, resource requirements, label enforcement, security standards, hostname conflict prevention. → references/kubernetes-admission-control.md

• Infrastructure as code — Terraform plan validation (raw Terraform and HCP Terraform/Enterprise input structures) and AWS CloudFormation hook policies. Encryption requirements, required tags, security group validation, multi-region compliance. → references/infrastructure-as-code.md

• HTTP API authorization — JWT-authenticated API gateway policies. Hierarchical authorization, method-based permissions, path-based authorization. → references/http-api-authorization.md

  • Request body validation (set subtraction for unknown fields, explicit iteration for required fields) → references/http-api-body-validation.md
  • Rate limiting (default rule := value tier-based fallbacks) → references/http-api-rate-limiting.md

• Access control models — RBAC, ABAC, separation of duty, time-based and location-based access. → references/access-control-models.md

• Metadata annotations — # METADATA blocks, entrypoints, severity classification, schema validation, opa inspect. → references/metadata-annotations.md

• Regal linter compliance — focused guides per Regal rule category, for when a specific lint rule needs more context than rules.md gives:

  • Naming conventions (prefer-snake-case, avoid-get-and-list-prefix, rule-name-repeats-package) → references/regal-naming-conventions.md
  • Iteration style (prefer-some-in-iteration, mixed-iteration) → references/regal-iteration-style.md
  • Membership operators (use-in-operator) → references/regal-membership-operators.md
  • Function style (external-reference, zero-arity-function) → references/regal-function-style.md
  • Default rules (trailing-default-rule, default-over-else) → references/regal-defaults.md
  • Boolean and rule structure (prefer-set-or-object-rule, boolean-assignment) → references/regal-boolean-structure.md
  • Comprehension patterns (object.keys, comprehension-term-assignment) → references/regal-comprehensions.md
  • Bug avoidance (not-equals-in-loop, sprintf-arguments-mismatch) → references/regal-bugs.md
  • Testing style (file-missing-test-suffix, test-outside-test-package) → references/regal-testing-style.md
  • Import conventions (prefer-package-imports, redundant-alias) → references/regal-imports.md
  • Annotations (missing-metadata, detached-metadata, no-defined-entrypoint) → references/regal-annotations.md

Additional resources

• OPA Documentation
• Rego Policy Language Reference
• OPA Playground
• Styra Academy
• Policy Library