✨ Add selectablefield marker

pkg/crd/markers/crd.go

@@ -55,6 +55,9 @@ var CRDMarkers = []*definitionWithHelp{
 
 	must(markers.MakeDefinition("kubebuilder:metadata", markers.DescribesType, Metadata{})).
 		WithHelp(Metadata{}.Help()),
+
+	must(markers.MakeDefinition("kubebuilder:selectablefield", markers.DescribesType, SelectableField{})).
+		WithHelp(SelectableField{}.Help()),
 }
 
 // TODO: categories and singular used to be annotations types
@@ -388,3 +391,32 @@ func (s Metadata) ApplyToCRD(crd *apiext.CustomResourceDefinition, _ string) err
 
 	return nil
 }
+
+// +controllertools:marker:generateHelp:category=CRD
+
+// SelectableField adds a field that may be used with field selectors.
+type SelectableField struct {
+	// JSONPath specifies the jsonpath expression which is used to produce a field selector value.
+	JSONPath string `marker:"JSONPath"`
+}
+
+func (s SelectableField) ApplyToCRD(crd *apiext.CustomResourceDefinitionSpec, version string) error {
+	var selectableFields *[]apiext.SelectableField
+	for i := range crd.Versions {
+		ver := &crd.Versions[i]
+		if ver.Name != version {
+			continue
+		}
+		selectableFields = &ver.SelectableFields
+		break
+	}
+	if selectableFields == nil {
+		return fmt.Errorf("selectable field applied to version %q not in CRD", version)
+	}
+
+	*selectableFields = append(*selectableFields, apiext.SelectableField{
+		JSONPath: s.JSONPath,
+	})
+
+	return nil
+}

pkg/crd/testdata/cronjob_types.go

@@ -349,6 +349,9 @@ type CronJobSpec struct {
 	// +optional
 	// +default="TCP"
 	Protocol corev1.Protocol `json:"protocol,omitempty" protobuf:"bytes,4,opt,name=protocol,casttype=Protocol"`
+
+	// This tests that selectable field.
+	SelectableFieldString string `json:"selectableFieldString,omitempty"`
 }
 
 type ContainsNestedMap struct {
@@ -634,6 +637,7 @@ type CronJobStatus struct {
 // +kubebuilder:resource:singular=mycronjob
 // +kubebuilder:storageversion
 // +kubebuilder:metadata:annotations="api-approved.kubernetes.io=https://github.com/kubernetes-sigs/controller-tools";"cert-manager.io/inject-ca-from-secret=cert-manager/cert-manager-webhook-ca"
+// +kubebuilder:selectablefield:JSONPath=`.spec.selectableFieldString`
 
 // CronJob is the Schema for the cronjobs API
 type CronJob struct {

pkg/crd/testdata/testdata.kubebuilder.io_cronjobs.yaml

@@ -8966,6 +8966,9 @@ spec:
                 type: string
               schemaless:
                 description: This tests that the schemaless marker works
+              selectableFieldString:
+                description: This tests that selectable field.
+                type: string
               startingDeadlineSeconds:
                 description: |-
                   Optional deadline in seconds for starting the job if it misses scheduled
@@ -9203,6 +9206,8 @@ spec:
                 type: string
             type: object
         type: object
+    selectableFields:
+    - jsonPath: .spec.selectableFieldString
     served: true
     storage: true
     subresources: