Add annotations filter based on kyaml libraries

api/builtins/AnnotationsTransformer.go

@@ -4,6 +4,8 @@
 package builtins
 
 import (
+	"sigs.k8s.io/kustomize/api/filters/annotations"
+	"sigs.k8s.io/kustomize/api/filters/filtersutil"
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/transform"
 	"sigs.k8s.io/kustomize/api/types"
@@ -14,6 +16,10 @@ import (
 type AnnotationsTransformerPlugin struct {
 	Annotations map[string]string `json:"annotations,omitempty" yaml:"annotations,omitempty"`
 	FieldSpecs  []types.FieldSpec `json:"fieldSpecs,omitempty" yaml:"fieldSpecs,omitempty"`
+
+	// YAMLSupport can be set to true to use the kyaml filter instead of the
+	// kunstruct transformer
+	YAMLSupport bool
 }
 
 func (p *AnnotationsTransformerPlugin) Config(
@@ -24,14 +30,27 @@ func (p *AnnotationsTransformerPlugin) Config(
 }
 
 func (p *AnnotationsTransformerPlugin) Transform(m resmap.ResMap) error {
-	t, err := transform.NewMapTransformer(
-		p.FieldSpecs,
-		p.Annotations,
-	)
-	if err != nil {
-		return err
+	if p.YAMLSupport {
+		for _, r := range m.Resources() {
+			err := filtersutil.ApplyToJSON(annotations.Filter{
+				Annotations: p.Annotations,
+				FsSlice:     p.FieldSpecs,
+			}, r.Kunstructured)
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	} else {
+		t, err := transform.NewMapTransformer(
+			p.FieldSpecs,
+			p.Annotations,
+		)
+		if err != nil {
+			return err
+		}
+		return t.Transform(m)
 	}
-	return t.Transform(m)
 }
 
 func NewAnnotationsTransformerPlugin() resmap.TransformerPlugin {