add MapTransformer and constructor for labels and annotations

pkg/kinflate/util/labelsandannotations.go

@@ -17,41 +17,45 @@ limitations under the License.
 package util
 
 import (
+	"errors"
 	"fmt"
 
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 )
 
-// MapTransformationOptions contains a map string->string and path configs
+// MapTransformer contains a map string->string and path configs
 // The map will be applied to the fields specified in path configs.
-type MapTransformationOptions struct {
+type MapTransformer struct {
 	m           map[string]string
 	pathConfigs []PathConfig
 }
 
-var _ Transformer = &MapTransformationOptions{}
+var _ Transformer = &MapTransformer{}
 
-// CompleteForLabels fills up the MapTransformationOptions for labels transformation.
-func (o *MapTransformationOptions) CompleteForLabels(m map[string]string, pathConfigs []PathConfig) {
-	o.m = m
-	if pathConfigs == nil {
-		pathConfigs = DefaultLabelsPathConfigs
-	}
-	o.pathConfigs = pathConfigs
+// NewDefaultingLabelsMapTransformer construct a MapTransformer with defaultLabelsPathConfigs.
+func NewDefaultingLabelsMapTransformer(m map[string]string) (Transformer, error) {
+	return NewMapTransformer(defaultLabelsPathConfigs, m)
 }
 
-// CompleteForAnnotations fills up the MapTransformationOptions for annotations transformation.
-func (o *MapTransformationOptions) CompleteForAnnotations(m map[string]string, pathConfigs []PathConfig) {
-	o.m = m
-	if pathConfigs == nil {
-		pathConfigs = DefaultAnnotationsPathConfigs
-	}
-	o.pathConfigs = pathConfigs
+// NewDefaultingAnnotationsMapTransformer construct a MapTransformer with defaultAnnotationsPathConfigs.
+func NewDefaultingAnnotationsMapTransformer(m map[string]string) (Transformer, error) {
+	return NewMapTransformer(defaultAnnotationsPathConfigs, m)
 }
 
-// Transform apply each <key, value> pair in the MapTransformationOptions to the
-// fields specified in MapTransformationOptions.
-func (o *MapTransformationOptions) Transform(m map[GroupVersionKindName]*unstructured.Unstructured) error {
+// NewMapTransformer construct a MapTransformer.
+func NewMapTransformer(pc []PathConfig, m map[string]string) (Transformer, error) {
+	if m == nil {
+		return nil, errors.New("map is not expected to be nil")
+	}
+	if pc == nil {
+		return nil, errors.New("pathConfigs is not expected to be nil")
+	}
+	return &MapTransformer{pathConfigs: pc, m: m}, nil
+}
+
+// Transform apply each <key, value> pair in the MapTransformer to the
+// fields specified in MapTransformer.
+func (o *MapTransformer) Transform(m map[GroupVersionKindName]*unstructured.Unstructured) error {
 	for gvkn := range m {
 		obj := m[gvkn]
 		objMap := obj.UnstructuredContent()
@@ -68,7 +72,7 @@ func (o *MapTransformationOptions) Transform(m map[GroupVersionKindName]*unstruc
 	return nil
 }
 
-func (o *MapTransformationOptions) addMap(in interface{}) (interface{}, error) {
+func (o *MapTransformer) addMap(in interface{}) (interface{}, error) {
 	m, ok := in.(map[string]interface{})
 	if !ok {
 		return nil, fmt.Errorf("%#v is expectd to be %T", in, m)

pkg/kinflate/util/labelsandannotations_test.go

@@ -24,16 +24,6 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 )
 
-var labelsOps = MapTransformationOptions{
-	m:           map[string]string{"label-key1": "label-value1", "label-key2": "label-value2"},
-	pathConfigs: DefaultLabelsPathConfigs,
-}
-
-var annotationsOps = MapTransformationOptions{
-	m:           map[string]string{"anno-key1": "anno-value1", "anno-key2": "anno-value2"},
-	pathConfigs: DefaultAnnotationsPathConfigs,
-}
-
 func makeConfigmap() *unstructured.Unstructured {
 	return &unstructured.Unstructured{
 		Object: map[string]interface{}{
@@ -218,7 +208,8 @@ func makeLabeledMap() map[GroupVersionKindName]*unstructured.Unstructured {
 
 func TestLabelsRun(t *testing.T) {
 	m := makeTestMap()
-	err := labelsOps.Transform(m)
+	lt, err := NewDefaultingLabelsMapTransformer(map[string]string{"label-key1": "label-value1", "label-key2": "label-value2"})
+	err = lt.Transform(m)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -326,7 +317,8 @@ func makeAnnotatedMap() map[GroupVersionKindName]*unstructured.Unstructured {
 
 func TestAnnotationsRun(t *testing.T) {
 	m := makeTestMap()
-	err := annotationsOps.Transform(m)
+	at, err := NewDefaultingAnnotationsMapTransformer(map[string]string{"anno-key1": "anno-value1", "anno-key2": "anno-value2"})
+	err = at.Transform(m)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}

pkg/kinflate/util/labelsandannotationsconfig.go

@@ -20,9 +20,9 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 )
 
-// DefaultLabelsPathConfigs is the default configuration for mutating labels and
+// defaultLabelsPathConfigs is the default configuration for mutating labels and
 // selector fields for native k8s APIs.
-var DefaultLabelsPathConfigs = []PathConfig{
+var defaultLabelsPathConfigs = []PathConfig{
 	{
 		Path:               []string{"metadata", "labels"},
 		CreateIfNotPresent: true,
@@ -109,9 +109,9 @@ var DefaultLabelsPathConfigs = []PathConfig{
 	},
 }
 
-// DefaultLabelsPathConfigs is the default configuration for mutating annotations
+// defaultLabelsPathConfigs is the default configuration for mutating annotations
 // fields for native k8s APIs.
-var DefaultAnnotationsPathConfigs = []PathConfig{
+var defaultAnnotationsPathConfigs = []PathConfig{
 	{
 		Path:               []string{"metadata", "annotations"},
 		CreateIfNotPresent: true,