K8s/Storage: Register field-selector on all kinds (#79822)

Co-authored-by: Dan Cech <dcech@grafana.com>

pkg/services/grafana-apiserver/service.go

@@ -324,6 +324,12 @@ func (s *service) start(ctx context.Context) error {
 		return err
 	}
 
+	// support folder selection
+	err = entitystorage.RegisterFieldSelectorSupport(Scheme)
+	if err != nil {
+		return err
+	}
+
 	// Create the server
 	server, err := serverConfig.Complete().New("grafana-apiserver", genericapiserver.NewEmptyDelegate())
 	if err != nil {

pkg/services/grafana-apiserver/storage/entity/fieldRequirements.go

@@ -0,0 +1,76 @@
+package entity
+
+import (
+	"fmt"
+	"strings"
+
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/selection"
+)
+
+const folderAnnoKey = "grafana.app/folder"
+
+type FieldRequirements struct {
+	// Equals folder
+	Folder *string
+}
+
+func ReadFieldRequirements(selector fields.Selector) (FieldRequirements, fields.Selector, error) {
+	requirements := FieldRequirements{}
+
+	if selector == nil {
+		return requirements, selector, nil
+	}
+
+	for _, r := range selector.Requirements() {
+		switch r.Field {
+		case folderAnnoKey:
+			if (r.Operator != selection.Equals) && (r.Operator != selection.DoubleEquals) {
+				return requirements, selector, apierrors.NewBadRequest("only equality is supported in the selectors")
+			}
+			folder := r.Value
+			requirements.Folder = &folder
+		}
+	}
+
+	// use Transform function to remove grafana.app/folder field selector
+	selector, err := selector.Transform(func(field, value string) (string, string, error) {
+		switch field {
+		case folderAnnoKey:
+			return "", "", nil
+		}
+		return field, value, nil
+	})
+
+	return requirements, selector, err
+}
+
+func RegisterFieldSelectorSupport(scheme *runtime.Scheme) error {
+	grafanaFieldSupport := runtime.FieldLabelConversionFunc(
+		func(field, value string) (string, string, error) {
+			if strings.HasPrefix(field, "grafana.app/") {
+				return field, value, nil
+			}
+			return "", "", getBadSelectorError(field)
+		},
+	)
+
+	// Register all the internal types
+	for gvk := range scheme.AllKnownTypes() {
+		if strings.HasSuffix(gvk.Group, ".grafana.app") {
+			err := scheme.AddFieldLabelConversionFunc(gvk, grafanaFieldSupport)
+			if err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func getBadSelectorError(f string) error {
+	return apierrors.NewBadRequest(
+		fmt.Sprintf("%q is not a known field selector: only %q works", f, folderAnnoKey),
+	)
+}

pkg/services/grafana-apiserver/storage/entity/storage.go

@@ -241,29 +241,16 @@ func (s *Storage) GetList(ctx context.Context, key string, opts storage.ListOpti
 		}
 	}
 
-	// translate grafana.app/folder field selector to folder condition
-	fields := opts.Predicate.Field.Requirements()
-	for _, f := range fields {
-		if f.Field == "grafana.app/folder" {
-			if f.Operator != selection.Equals {
-				return apierrors.NewBadRequest("grafana.app/folder field selector only supports equality")
-			}
-
-			// select items in the spcified folder
-			req.Folder = f.Value
-		}
-	}
-
-	// use Transform function to remove grafana.app/folder field selector
-	opts.Predicate.Field, err = opts.Predicate.Field.Transform(func(field, value string) (string, string, error) {
-		if field == "grafana.app/folder" {
-			return "", "", nil
-		}
-		return field, value, nil
-	})
+	// translate grafana.app/folder field selector to the folder condition
+	fieldRequirements, fieldSelector, err := ReadFieldRequirements(opts.Predicate.Field)
 	if err != nil {
 		return err
 	}
+	if fieldRequirements.Folder != nil {
+		req.Folder = *fieldRequirements.Folder
+	}
+	// Update the field selector to remove the unneeded selectors
+	opts.Predicate.Field = fieldSelector
 
 	rsp, err := s.store.List(ctx, req)
 	if err != nil {