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kcc-identity-reference

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Creates or updates the _identity.go and _reference.go files for a Config Connector resource, ensuring they follow the canonical gcpurls.Template pattern. Use this when you need to make sure the identity and reference is up to date for a KCC resource or when implementing IdentityV2 and refs.Ref for a resource.

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Kcc Identity Reference

Overview

This skill guides you through creating or updating the _identity.go and _reference.go files for a given Config Connector resource (e.g. MemoryStoreInstance). The goal is to implement identity.IdentityV2 and refs.Ref using the canonical gcpurls.Template pattern, identical to the pattern used in apis/artifactregistry/v1beta1/artifactregistryrepository_identity.go.

Hints

  • If the identity or reference files already exist, do not update the copyright year.

Workflow

When asked to update or create the identity and reference for a "resource of the day" (e.g., group: memorystore.cnrm.cloud.google.com, kind: MemoryStoreInstance), follow these steps:

Step 1: Locate the target files

  1. Identify the groupPrefix (the group without the .cnrm.cloud.google.com suffix). Example: memorystore
  2. Look for the resource version directory under apis/<groupPrefix>/. Example: apis/memorystore/v1beta1/ or apis/memorystore/v1alpha1/. (Check the filesystem to see which versions exist).
  3. The files to edit/create are apis/<groupPrefix>/<version>/<kind>_identity.go and apis/<groupPrefix>/<version>/<kind>_reference.go.
    • Note: <kind> is typically the full lowercase Kind, e.g. memorystoreinstance. Sometimes the groupPrefix is dropped, so check if the files already exist.

Step 2: Determine the Identity Template

  1. Read the corresponding line in docs/ai/metadata/cloudassetinventory_names.jsonl using grep. Search for the resource kind to find its URL format.
    • Example: grep -i memorystore docs/ai/metadata/cloudassetinventory_names.jsonl
    • Output might be: {"resourceType": "memorystore.googleapis.com/Instance", "nameFormats": ["//memorystore.googleapis.com/projects/{{PROJECT_ID}}/locations/{{LOCATION}}/instances/{{INSTANCE}}"]}
    • Note: If the resource is missing from cloudassetinventory_names.jsonl (e.g. not handled by CAIS), check the existing _identity.go or direct controller to infer the URL format. Pay attention to camelCase path segments (e.g. entryGroups instead of entrygroups), as GCP URLs are case-sensitive. Additionally, if the resource is missing from cloudassetinventory_names.jsonl, you will also need to add its URL format as an exception in pkg/gcpurls/registry_test.go to prevent the TestRegisteredTemplatesMatchCAI test from failing.
  2. Map the format to the gcpurls.Template format: "projects/{project}/locations/{location}/instances/{instance}".
  3. Read the canonical apis/artifactregistry/v1beta1/artifactregistryrepository_identity.go to refresh your understanding of the implementation details.

Step 3: Implement the Identity (<kind>_identity.go)

Create or update the file to match the canonical example. Key requirements:

  • Use the standard copyright header (Year 2026).
  • Declare interface implementations: _ identity.IdentityV2 = &<Kind>Identity{} (or _ identity.ServerGeneratedIdentity = &<Kind>Identity{} if the resource has a server-generated ID) and _ identity.Resource = &<Kind>{}
  • Define the template var: var <Kind>IdentityFormat = gcpurls.Template[<Kind>Identity]("api.googleapis.com", "projects/{project}/...")
  • The struct must map exactly to the template fields (e.g., Project string, Location string, Instance string) and have // +k8s:deepcopy-gen=false.
    • Important: Add a standard Go doc comment like // <Kind>Identity is the identity of a GCP <Kind> resource. right above the struct definition.
    • Important: The variables in your gcpurls.Template (e.g. {instance}) MUST match the struct fields when both are lowercased (e.g. {deploymentresourcepool} matches DeploymentResourcePool). Do not use underscores in the template variables (e.g. {deployment_resource_pool}) or Go struct fields (e.g. Deployment_resource_pool). For GCP URL templates that originally contain snake_case placeholders (e.g. {aspect_type}), you must map them to camelCase variables in the gcpurls.Template (e.g., {aspectType}) and use CamelCase in the corresponding Go struct fields (e.g., AspectType string). Avoid snake_case fields with underscores (such as Aspect_type string) in Go structs entirely.
    • Note: If an existing deepcopy method was previously generated for this identity struct, run dev/tasks/generate-types-and-mappers to regenerate the types and remove the obsolete code.
  • Implement String(), FromExternal(ref string), and Host() by delegating to the format var.
  • For Server-Generated IDs: If the resource can have its ID generated by the GCP server when not specified in the spec, implement identity.ServerGeneratedIdentity instead of identity.IdentityV2.
    • Implement HasIdentitySpecified() bool (e.g., return i.ID != "").
    • In GetIdentity(), if obj.Status.ExternalRef is set, parse it to extract the authoritative server-generated ID and default the empty spec identity ID field to it prior to cross-checking or returning. See apis/bigqueryconnection/v1beta1/bigqueryconnectionconnection_identity.go for the exact reference implementation.
  • Implement ParentString() to return the GCP parent URI string (e.g., projects/{project} or projects/{project}/locations/{location}) to simplify parent path construction in controllers.
  • Implement getIdentityFrom<Kind>Spec(ctx context.Context, reader client.Reader, obj *<Kind>) (*<Kind>Identity, error) to extract fields from the spec/obj (often using refs.ResolveProjectID, refs.GetLocation, etc.).
    • Important: This function MUST take a typed pointer *<Kind> directly. If any callers (such as Normalize fallback) only have an *unstructured.Unstructured object, those callers must first convert it using common.ToStructuredType[*<Kind>](unstructuredObj) before calling getIdentityFrom<Kind>Spec. This keeps the extraction code highly type-safe and avoids manual unstructured field parsing.
  • Implement Boilerplate and GetIdentity(ctx, reader) on the Resource struct:

    • CRITICAL / MANDATORY STATUS CROSS-CHECK IN GETIDENTITY: In GetIdentity, you MUST always cross-check the parsed identity from spec against status.externalRef or whatever other status field holds the identity for created objects (e.g. status.name). This prevents drift and guarantees that the identity resolved is authoritative for created objects. If the resource is created, its identity MUST come from status; we cross-check spec against status to detect drift.

    • CRITICAL / MANDATORY: Do NOT change the schema (e.g., do not add status.externalRef or status.name fields to the _types.go file if they are not already there) in this phase. If the resource's Status struct does not already contain an ExternalRef or Name field, do NOT perform any cross-check against the status in GetIdentity. Simply return the parsed specIdentity without checking status. We should never change the schema to introduce an identity or reference.

    • Verification: Always run dev/tasks/diff-crds to check and guarantee that we have not changed the schema in any way.

    • Note: If you are updating an existing resource's Identity struct to the IdentityV2 pattern, be sure to check for existing usages of the struct and its old methods (e.g. .Parent(), .ID()) in dependent identity files and direct controllers, and update them to use the new fields (e.g. .Project, .Location, etc.). The compiler is your friend: remove the functions, then run go vet ./... or go build ./... to look for references to functions that no longer exist.

Step 4: Implement the Reference (<kind>_reference.go)

Read the canonical apis/artifactregistry/v1beta1/artifactregistryrepository_reference.go to refresh your understanding.

CRITICAL RULE FOR REFERENCE TYPES: Whenever a reference type (e.g., <Kind>Ref implementing refsv1beta1.Ref) is needed, it must always be defined and implemented in its own separate file named <kind>_reference.go rather than inside _types.go. This keeps the API types clean and ensures reference-related types are organized consistently across packages.

Create or update the file to match the canonical example. Key requirements:

  • Use the standard copyright header (Year 2026).
  • Implement _ refs.Ref = &<Kind>Ref{}.
  • Define the GVK variable: var <Kind>GVK = schema.GroupVersionKind{...} (It is also acceptable if this is defined in <kind>_types.go).
  • Define the <Kind>Ref struct with exactly 3 fields: External, Name, and Namespace.
    • Important: Add a clean, simple doc comment like // <Kind>Ref is a reference to a GCP <Kind>. right above the struct definition. Avoid verbose or awkward boilerplate phrasing like "defines the resource reference to..." or "which External field...".
    • The External field MUST have specific godoc: "A reference to an externally managed <Kind> resource. Should be in the format \"projects/{{projectID}}/...\"". Do not use generic docstrings.
    • The Name and Namespace fields should have godocs: "The name of a <Kind> resource." and "The namespace of a <Kind> resource.".
  • Include func init() { refs.Register(&<Kind>Ref{}) }.
  • Implement boilerplate methods: GetGVK, GetNamespacedName, GetExternal, SetExternal, ValidateExternal, ParseExternalToIdentity.
  • Implement Normalize to populate the External field:
    • CRITICAL WARNING: If the referenced resource is a direct controller or any modern resource that supports status.externalRef (or equivalent status-based identity), NEVER use NormalizeWithFallback or any custom fallback function that reads from the spec (such as calling getIdentityFrom<Kind>Spec). You MUST delegate Normalize directly to refs.Normalize.
    • Why? refs.Normalize reads strictly from status and avoids using spec. If a reference looks at the spec (via getIdentityFrom<Kind>Spec) during normalization before the resource is fully ready/created in GCP, it will prematurely return an identity string. This leads to broken dependency validation, reconciliation loops, and cascading lookup failures because dependent resources assume the dependency is ready when it is not.
    • Legacy Fallbacks: Only use refs.NormalizeWithFallback for older, legacy resources (e.g. DCL or Terraform) that completely lack status.externalRef.
    • CRITICAL GUIDELINES FOR FALLBACK FUNCTION IN NORMALIZE (LEGACY ONLY):
      1. The fallback function is ONLY for when status.externalRef is not available. It MUST first check if the referenced resource is fully reconciled and ready in GCP by inspecting status fields. It should look at status.conditions (i.e. checking if the Ready condition is True) or whatever other status field signals that the object is ready (such as status.state, status.selfLink, etc.).
      2. If the status fields indicate that the resource is not ready, the fallback function MUST return "" (empty string). This will correctly bubble up a k8s.NewReferenceNotReadyError.
      3. If and only if the status fields indicate that the resource is ready, the fallback function may construct and return the external identity string. It should use spec fields (by converting the unstructured object using common.ToStructuredType and calling getIdentityFrom<Kind>Spec) as a last-resort fallback to build the identity. (No spec/status cross-checking is needed inside Normalize itself).

Step 5: Verify

  1. Write Unit Tests:

    • Write comprehensive unit tests for the Identity (e.g., <kind>_identity_test.go).
    • Do NOT create a separate <kind>_reference_test.go file (as it typically duplicates the parsing and formatting tests of the identity). Instead, add any validation or format test cases directly to the identity unit tests.
    • You MUST use github.com/google/go-cmp/cmp (with the cmp.Diff function) when comparing structs or multiple fields in tests, to ensure precise, clear diff outputs on failures.
    • Always use the standard got/want mismatch format for failures, e.g. (-want +got):\n%s.
    • CRITICAL: When creating/modifying an identity type, always run TestGoldenIdentitiesYamlFiles (defined in pkg/cli/powertools/cais/cmd_test.go) with WRITE_GOLDEN_OUTPUT=1 using WRITE_GOLDEN_OUTPUT=1 go test -v ./pkg/cli/powertools/cais/... to generate or update the golden output _identities.yaml file(s) for the test fixtures. This prevents presubmit CI unit test failures.

  2. Run Compilations and Linters:

    • Ensure the code compiles and there are no lint errors. You MUST always run go vet ./... and go build ./... before sending the PR to verify that your changes have not introduced any compilation errors across the entire project.
    • If any CRDs, schemas, or reference definitions changed, always run make resource-docs to regenerate the resource documentation and prevent doc validation pipeline breakages.