Add builtin namespace transformer plugin

pkg/target/kusttarget.go

@@ -265,8 +265,6 @@ func (kt *KustTarget) runTransformers(ra *accumulator.ResAccumulator) error {
 	}
 	r = append(r, t)
 	tConfig := ra.GetTransformerConfig()
-	r = append(r, transformers.NewNamespaceTransformer(
-		string(kt.kustomization.Namespace), tConfig.NameSpace))
 	lts, err := kt.configureBuiltinTransformers(tConfig)
 	if err != nil {
 		return err

pkg/target/kusttarget_configplugin.go

@@ -63,8 +63,8 @@ func (kt *KustTarget) configureBuiltinTransformers(
 	// TODO: Convert remaining legacy transformers to plugins
 	//   with tests:
 	//   - patch SMP
-	//   - namespace
 	configurators := []transformerConfigurator{
+		kt.configureBuiltinNamespaceTransformer,
 		kt.configureBuiltinNameTransformer,
 		kt.configureBuiltinImageTagTransformer,
 		kt.configureBuiltinLabelTransformer,
@@ -124,6 +124,24 @@ func (kt *KustTarget) configureBuiltinConfigMapGenerator() (
 	return
 }
 
+func (kt *KustTarget) configureBuiltinNamespaceTransformer(
+	tConfig *config.TransformerConfig) (
+	result []transformers.Transformer, err error) {
+	var c struct {
+		Namespace  string
+		FieldSpecs []config.FieldSpec
+	}
+	c.Namespace = kt.kustomization.Namespace
+	c.FieldSpecs = tConfig.NameSpace
+	p := builtin.NewNamespaceTransformerPlugin()
+	err = kt.configureBuiltinPlugin(p, c, "namespace")
+	if err != nil {
+		return nil, err
+	}
+	result = append(result, p)
+	return
+}
+
 func (kt *KustTarget) configureBuiltinPatchJson6902Transformer(
 	tConfig *config.TransformerConfig) (
 	result []transformers.Transformer, err error) {

pkg/transformers/namespace.go

@@ -130,7 +130,10 @@ func (o *namespaceTransformer) updateClusterRoleBinding(m resmap.ResMap) {
 			continue
 		}
 		objMap := m[id].Map()
-		subjects := objMap["subjects"].([]interface{})
+		subjects, ok := objMap["subjects"].([]interface{})
+		if subjects == nil || !ok {
+			continue
+		}
 		for i := range subjects {
 			subject := subjects[i].(map[string]interface{})
 			kind, foundk := subject["kind"]