Enable optionalfields linter

Author: sbueringer

.golangci-kal.yml

@@ -22,6 +22,8 @@ linters:
               - "maxlength" # Ensure all strings and arrays have maximum lengths/maximum items.
               - "nobools" # Bools do not evolve over time, should use enums instead.
               - "nofloats" # Ensure floats are not used.
+              - "optionalfields" # Ensure that all fields marked as optional adhere to being pointers and
+                                 # having the `omitempty` value in their `json` tag where appropriate.
               - "optionalorrequired" # Every field should be marked as `+optional` or `+required`.
               - "requiredfields" # Required fields should not be pointers, and should not have `omitempty`.
               - "statussubresource" # All root objects that have a `status` field should have a status subresource.
@@ -44,6 +46,12 @@ linters:
           # optionalOrRequired:
           #   preferredOptionalMarker: optional | kubebuilder:validation:Optional # The preferred optional marker to use, fixes will suggest to use this marker. Defaults to `optional`.
           #   preferredRequiredMarker: required | kubebuilder:validation:Required # The preferred required marker to use, fixes will suggest to use this marker. Defaults to `required`.
+            optionalFields:
+              pointers:
+                preference: Always # Always | WhenRequired # Whether to always require pointers, or only when required. Defaults to `Always`.
+                policy: SuggestFix # SuggestFix | Warn # The policy for pointers in optional fields. Defaults to `SuggestFix`.
+              omitempty:
+                policy: SuggestFix # SuggestFix | Warn | Ignore # The policy for omitempty in optional fields. Defaults to `SuggestFix`.
           # requiredFields:
           #   pointerPolicy: Warn | SuggestFix # Defaults to `SuggestFix`. We want our required fields to not be pointers.
 

hack/tools/.custom-gcl.yaml

@@ -2,5 +2,5 @@ version: v2.1.0
 name: golangci-lint-kube-api-linter
 destination: ./bin
 plugins:
-- module: 'sigs.k8s.io/kube-api-linter'
-  version: v0.0.0-20250515061849-37102c8f17a9
+- module: sigs.k8s.io/kube-api-linter
+  path: ../../../kube-api-linter