K8s: Add storage dual writer (#75403)

pkg/services/grafana-apiserver/registry/generic/strategy.go

@@ -0,0 +1,79 @@
+package generic
+
+import (
+	"context"
+
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/fields"
+	"k8s.io/apimachinery/pkg/labels"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/validation/field"
+	"k8s.io/apiserver/pkg/storage"
+	"k8s.io/apiserver/pkg/storage/names"
+)
+
+type genericStrategy struct {
+	runtime.ObjectTyper
+	names.NameGenerator
+}
+
+// NewStrategy creates and returns a genericStrategy instance.
+func NewStrategy(typer runtime.ObjectTyper) genericStrategy {
+	return genericStrategy{typer, names.SimpleNameGenerator}
+}
+
+// NamespaceScoped returns true because all Generic resources must be within a namespace.
+func (genericStrategy) NamespaceScoped() bool {
+	return true
+}
+
+func (genericStrategy) PrepareForCreate(ctx context.Context, obj runtime.Object) {}
+
+func (genericStrategy) PrepareForUpdate(ctx context.Context, obj, old runtime.Object) {}
+
+func (genericStrategy) Validate(ctx context.Context, obj runtime.Object) field.ErrorList {
+	return field.ErrorList{}
+}
+
+// WarningsOnCreate returns warnings for the creation of the given object.
+func (genericStrategy) WarningsOnCreate(ctx context.Context, obj runtime.Object) []string { return nil }
+
+func (genericStrategy) AllowCreateOnUpdate() bool {
+	return false
+}
+
+func (genericStrategy) AllowUnconditionalUpdate() bool {
+	return false
+}
+
+func (genericStrategy) Canonicalize(obj runtime.Object) {}
+
+func (genericStrategy) ValidateUpdate(ctx context.Context, obj, old runtime.Object) field.ErrorList {
+	return field.ErrorList{}
+}
+
+// WarningsOnUpdate returns warnings for the given update.
+func (genericStrategy) WarningsOnUpdate(ctx context.Context, obj, old runtime.Object) []string {
+	return nil
+}
+
+// GetAttrs returns labels and fields of an object.
+func GetAttrs(obj runtime.Object) (labels.Set, fields.Set, error) {
+	accessor, err := meta.Accessor(obj)
+	if err != nil {
+		return nil, nil, err
+	}
+	fieldsSet := fields.Set{
+		"metadata.name": accessor.GetName(),
+	}
+	return labels.Set(accessor.GetLabels()), fieldsSet, nil
+}
+
+// Matcher returns a generic.SelectionPredicate that matches on label and field selectors.
+func Matcher(label labels.Selector, field fields.Selector) storage.SelectionPredicate {
+	return storage.SelectionPredicate{
+		Label:    label,
+		Field:    field,
+		GetAttrs: GetAttrs,
+	}
+}