Load default config for image transformer

pkg/target/kusttarget.go

@@ -312,7 +312,7 @@ func (kt *KustTarget) newTransformer(
 		return nil, err
 	}
 	r = append(r, t)
-	t, err = transformers.NewImageTransformer(kt.kustomization.Images)
+	t, err = transformers.NewImageTransformer(kt.kustomization.Images, tConfig.Images)
 	if err != nil {
 		return nil, err
 	}

pkg/transformers/config/defaultconfig/defaultconfig.go

@@ -31,6 +31,7 @@ func GetDefaultFieldSpecs() []byte {
 		[]byte(namespaceFieldSpecs),
 		[]byte(varReferenceFieldSpecs),
 		[]byte(nameReferenceFieldSpecs),
+		[]byte(imageFieldSpecs),
 	}
 	return bytes.Join(configData, []byte("\n"))
 }
@@ -45,5 +46,6 @@ func GetDefaultFieldSpecsAsMap() map[string]string {
 	result["namespace"] = namespaceFieldSpecs
 	result["varreference"] = varReferenceFieldSpecs
 	result["namereference"] = nameReferenceFieldSpecs
+	result["image"] = imageFieldSpecs
 	return result
 }

pkg/transformers/config/defaultconfig/image.go

@@ -0,0 +1,25 @@
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package defaultconfig
+
+const (
+	imageFieldSpecs = `
+image:
+- path: containers
+- path: initContainers
+`
+)

pkg/transformers/config/transformerconfig.go

@@ -34,6 +34,7 @@ type TransformerConfig struct {
 	CommonAnnotations fsSlice  `json:"commonAnnotations,omitempty" yaml:"commonAnnotations,omitempty"`
 	NameReference     nbrSlice `json:"nameReference,omitempty" yaml:"nameReference,omitempty"`
 	VarReference      fsSlice  `json:"varReference,omitempty" yaml:"varReference,omitempty"`
+	Images            fsSlice  `json:"image,omitempty" yaml:"image,omitempty"`
 }
 
 // MakeEmptyConfig returns an empty TransformerConfig object
@@ -59,6 +60,7 @@ func (t *TransformerConfig) sortFields() {
 	sort.Sort(t.CommonAnnotations)
 	sort.Sort(t.NameReference)
 	sort.Sort(t.VarReference)
+	sort.Sort(t.Images)
 }
 
 // AddPrefixFieldSpec adds a FieldSpec to NamePrefix
@@ -129,6 +131,10 @@ func (t *TransformerConfig) Merge(input *TransformerConfig) (
 	if err != nil {
 		return nil, err
 	}
+	merged.Images, err = t.Images.mergeAll(input.Images)
+	if err != nil {
+		return nil, err
+	}
 	merged.sortFields()
 	return merged, nil
 }

pkg/transformers/image.go

@@ -23,18 +23,20 @@ import (
 
 	"sigs.k8s.io/kustomize/pkg/image"
 	"sigs.k8s.io/kustomize/pkg/resmap"
+	"sigs.k8s.io/kustomize/pkg/transformers/config"
 )
 
 // imageTransformer replace image names and tags
 type imageTransformer struct {
 	images     []image.Image
+	fieldSpecs []config.FieldSpec
 }
 
 var _ Transformer = &imageTransformer{}
 
 // NewImageTransformer constructs an imageTransformer.
-func NewImageTransformer(slice []image.Image) (Transformer, error) {
+func NewImageTransformer(slice []image.Image, fs []config.FieldSpec) (Transformer, error) {
-	return &imageTransformer{slice}, nil
+	return &imageTransformer{slice, fs}, nil
 }
 
 // Transform finds the matching images and replaces name, tag and/or digest
@@ -58,9 +60,9 @@ func (pt *imageTransformer) Transform(resources resmap.ResMap) error {
  finds matched ones and update the image name and tag name
 */
 func (pt *imageTransformer) findAndReplaceImage(obj map[string]interface{}) error {
-	paths := []string{"containers", "initContainers"}
 	found := false
-	for _, path := range paths {
+	for _, fs := range pt.fieldSpecs {
+		path := fs.Path
 		_, found = obj[path]
 		if found {
 			err := pt.updateContainers(obj, path)