Introduce Comparator interface (#88016)

* Introduce Comparator interface

* Add compare implementation everywhere

* Add comment explaining what Compare should do

* Lint

pkg/registry/apis/dashboard/register.go

@@ -1,15 +1,11 @@
 package dashboard
 
 import (
-	"fmt"
-	"time"
-
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/runtime/serializer"
 	"k8s.io/apiserver/pkg/registry/generic"
-	genericregistry "k8s.io/apiserver/pkg/registry/generic/registry"
 	"k8s.io/apiserver/pkg/registry/rest"
 	genericapiserver "k8s.io/apiserver/pkg/server"
 	common "k8s.io/kube-openapi/pkg/common"
@@ -24,7 +20,6 @@ import (
 	"github.com/grafana/grafana/pkg/registry/apis/dashboard/access"
 	"github.com/grafana/grafana/pkg/services/accesscontrol"
 	"github.com/grafana/grafana/pkg/services/apiserver/endpoints/request"
-	"github.com/grafana/grafana/pkg/services/apiserver/utils"
 	"github.com/grafana/grafana/pkg/services/dashboards"
 	dashver "github.com/grafana/grafana/pkg/services/dashboardversion"
 	"github.com/grafana/grafana/pkg/services/featuremgmt"
@@ -119,43 +114,10 @@ func (b *DashboardsAPIBuilder) GetAPIGroupInfo(
 	apiGroupInfo := genericapiserver.NewDefaultAPIGroupInfo(v0alpha1.GROUP, scheme, metav1.ParameterCodec, codecs)
 
 	resourceInfo := v0alpha1.DashboardResourceInfo
-	strategy := grafanaregistry.NewStrategy(scheme)
-	store := &genericregistry.Store{
-		NewFunc:                   resourceInfo.NewFunc,
-		NewListFunc:               resourceInfo.NewListFunc,
-		PredicateFunc:             grafanaregistry.Matcher,
-		DefaultQualifiedResource:  resourceInfo.GroupResource(),
-		SingularQualifiedResource: resourceInfo.SingularGroupResource(),
-		CreateStrategy:            strategy,
-		UpdateStrategy:            strategy,
-		DeleteStrategy:            strategy,
+	store, err := newStorage(scheme)
+	if err != nil {
+		return nil, err
 	}
-	store.TableConvertor = utils.NewTableConverter(
-		store.DefaultQualifiedResource,
-		[]metav1.TableColumnDefinition{
-			{Name: "Name", Type: "string", Format: "name"},
-			{Name: "Title", Type: "string", Format: "string", Description: "The dashboard name"},
-			{Name: "Created At", Type: "date"},
-		},
-		func(obj any) ([]interface{}, error) {
-			dash, ok := obj.(*v0alpha1.Dashboard)
-			if ok {
-				return []interface{}{
-					dash.Name,
-					dash.Spec.GetNestedString("title"),
-					dash.CreationTimestamp.UTC().Format(time.RFC3339),
-				}, nil
-			}
-			summary, ok := obj.(*v0alpha1.DashboardSummary)
-			if ok {
-				return []interface{}{
-					dash.Name,
-					summary.Spec.Title,
-					dash.CreationTimestamp.UTC().Format(time.RFC3339),
-				}, nil
-			}
-			return nil, fmt.Errorf("expected dashboard or summary")
-		})
 
 	legacyStore := &dashboardStorage{
 		resource:       resourceInfo,

pkg/registry/apis/dashboard/storage.go

@@ -0,0 +1,72 @@
+package dashboard
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/grafana/grafana/pkg/apis/dashboard/v0alpha1"
+	"github.com/grafana/grafana/pkg/services/apiserver/utils"
+	"k8s.io/apimachinery/pkg/runtime"
+
+	grafanaregistry "github.com/grafana/grafana/pkg/apiserver/registry/generic"
+	grafanarest "github.com/grafana/grafana/pkg/apiserver/rest"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	genericregistry "k8s.io/apiserver/pkg/registry/generic/registry"
+)
+
+var _ grafanarest.Storage = (*storage)(nil)
+
+type storage struct {
+	*genericregistry.Store
+}
+
+func newStorage(scheme *runtime.Scheme) (*storage, error) {
+	strategy := grafanaregistry.NewStrategy(scheme)
+	resourceInfo := v0alpha1.DashboardResourceInfo
+	store := &genericregistry.Store{
+		NewFunc:                   resourceInfo.NewFunc,
+		NewListFunc:               resourceInfo.NewListFunc,
+		PredicateFunc:             grafanaregistry.Matcher,
+		DefaultQualifiedResource:  resourceInfo.GroupResource(),
+		SingularQualifiedResource: resourceInfo.SingularGroupResource(),
+		CreateStrategy:            strategy,
+		UpdateStrategy:            strategy,
+		DeleteStrategy:            strategy,
+	}
+
+	store.TableConvertor = utils.NewTableConverter(
+		store.DefaultQualifiedResource,
+		[]metav1.TableColumnDefinition{
+			{Name: "Name", Type: "string", Format: "name"},
+			{Name: "Title", Type: "string", Format: "string", Description: "The dashboard name"},
+			{Name: "Created At", Type: "date"},
+		},
+		func(obj any) ([]interface{}, error) {
+			dash, ok := obj.(*v0alpha1.Dashboard)
+			if ok {
+				if dash != nil {
+					return []interface{}{
+						dash.Name,
+						dash.Spec.GetNestedString("title"),
+						dash.CreationTimestamp.UTC().Format(time.RFC3339),
+					}, nil
+				}
+			}
+			summary, ok := obj.(*v0alpha1.DashboardSummary)
+			if ok {
+				return []interface{}{
+					dash.Name,
+					summary.Spec.Title,
+					dash.CreationTimestamp.UTC().Format(time.RFC3339),
+				}, nil
+			}
+			return nil, fmt.Errorf("expected dashboard or summary")
+		})
+	return &storage{Store: store}, nil
+}
+
+// Compare asserts on the equality of objects returned from both stores	(object storage and legacy storage)
+func (s *storage) Compare(storageObj, legacyObj runtime.Object) bool {
+	//TODO: define the comparison logic between a dashboard returned by the storage and a dashboard returned by the legacy storage
+	return false
+}

pkg/registry/apis/folders/storage.go

@@ -38,3 +38,9 @@ func newStorage(scheme *runtime.Scheme, optsGetter generic.RESTOptionsGetter, le
 	}
 	return &storage{Store: store}, nil
 }
+
+// Compare asserts on the equality of objects returned from both stores	(object storage and legacy storage)
+func (s *storage) Compare(storageObj, legacyObj runtime.Object) bool {
+	//TODO: define the comparison logic between a folder returned by the storage and a folder returned by the legacy storage
+	return false
+}

pkg/registry/apis/peakq/storage.go

@@ -60,3 +60,9 @@ func newStorage(scheme *runtime.Scheme, optsGetter generic.RESTOptionsGetter) (*
 	}
 	return &storage{Store: store}, nil
 }
+
+// Compare asserts on the equality of objects returned from both stores	(object storage and legacy storage)
+func (s *storage) Compare(storageObj, legacyObj runtime.Object) bool {
+	//TODO: define the comparison logic between a query template returned by the storage and a query template returned by the legacy storage
+	return false
+}

pkg/registry/apis/playlist/storage.go

@@ -38,3 +38,9 @@ func newStorage(scheme *runtime.Scheme, optsGetter generic.RESTOptionsGetter, le
 	}
 	return &storage{Store: store}, nil
 }
+
+// Compare asserts on the equality of objects returned from both stores	(object storage and legacy storage)
+func (s *storage) Compare(storageObj, legacyObj runtime.Object) bool {
+	//TODO: define the comparison logic between a playlist returned by the storage and a playlist returned by the legacy storage
+	return false
+}

pkg/registry/apis/scope/storage.go

@@ -184,3 +184,9 @@ func SelectableScopeNodeFields(obj *scope.ScopeNode) fields.Set {
 		"spec.parentName": parentName,
 	})
 }
+
+// Compare asserts on the equality of objects returned from both stores	(object storage and legacy storage)
+func (s *storage) Compare(storageObj, legacyObj runtime.Object) bool {
+	//TODO: define the comparison logic between a scope returned by the storage and a scope returned by the legacy storage
+	return false
+}

pkg/registry/apis/service/storage.go

@@ -60,3 +60,9 @@ func newStorage(scheme *runtime.Scheme, optsGetter generic.RESTOptionsGetter) (*
 	}
 	return &storage{Store: store}, nil
 }
+
+// Compare asserts on the equality of objects returned from both stores	(object storage and legacy storage)
+func (s *storage) Compare(storageObj, legacyObj runtime.Object) bool {
+	//TODO: define the comparison logic between a generic object returned by the storage and a generic object returned by the legacy storage
+	return false
+}