atmos-policy

Atmos Policy

Use this skill for the experimental policy engine and reusable library, not for general validation or ordinary lifecycle-hook configuration. Use atmos-hooks for non-policy hook definitions and atmos-validation for existing JSON Schema/OPA settings.validation behavior.

Establish capabilities before authoring

Check the installed Atmos version/help and the matching source/docs. Do not infer a command exists from the PRD: atmos policy check/test/explain is proposed, not implemented in this branch.

The current opt-in is policy.d/ at the project root that atmos.yaml discovery selects (the working directory, then the Git root, then the nearest ancestor with atmos.yaml), overridden by ATMOS_POLICY_DIR, containing strict atmos/v1 kind: Policy documents. Inline CEL and restricted Starlark run. A Starlark predicate is a function body over detached, read-only JSON data that must return a strict boolean; it has no automation host, module loader, filesystem, network, or logging API. Rego is not available through this loader. Existing Rego validation is separate and remains supported. Do not migrate legacy configuration to proposed policy: attachments yet.

Use central match selectors for instance attachments: literal labels (all), tags (any by default, tag_mode: all supported), exact component names, stacks, and component types. These use resolved metadata from existing inheritance, not inline policy inheritance. Protect the governing directory.

Distinguish input kind, component type, and CI provider:

• terraform.plan: native JSON extracted privately from a saved binary plan. Evaluated after successful plan, including no-change plans, and again before applying the evaluated private copy. Implicit apply/deploy and direct destroy are rejected when plan policies are enabled.
• operation: lifecycle event, component type/name, stack, command, status, exit code, dry-run. Current integration uses existing Terraform, Helmfile, Helm, and Kubernetes hooks. Do not claim enforcement for Packer, Ansible, containers, emulators, or custom components yet.
• plugin (on: plugin): native plugin registries, packages, and local builds (origin, path, profiles, operation) checked before install, activation, test, publish, and sign. See atmos-plugins for inputs and recipes.
• GitHub Actions context: ci.provider == 'github-actions', ci.schema == 'github-actions/v1'. Metadata retains allowlisted environment variable names under ci.metadata.data; native event fields remain under ci.event.data. No tokens or arbitrary environment variables are copied. Events are triggering evidence, not current reviews. Missing required data blocks.
• atmos.affected: deny rules run in shared affected analysis before output filtering/scheduling. Inputs include files, instances, component/stack groups, and structured before/after fields. Collection requires clean worktrees; static inventories use the active, protected discovery configuration on both revisions. This is not independent historical discovery or a transitive execution graph. Missing imports and unsupported inventory types block. Inspect before/after explicitly; affected rules do not accept single-instance match or dispatch lifecycle hooks.
• git.change, function/source, and approval input types have core contracts or design examples, not complete CLI collectors/enforcement. Affected is explicit; ordinary lifecycle and saved-plan rules do not depend on --affected.