add legacy filter to image tag transformer

plugin/builtin/imagetagtransformer/ImageTagTransformer.go

@@ -35,14 +35,15 @@ func (p *plugin) Config(
 
 func (p *plugin) Transform(m resmap.ResMap) error {
 	for _, r := range m.Resources() {
-		// If you're here because someone expected any field containing
-		// the string "containers" or "initContainers" to get an image
-		// update (not just spec/template/spec/containers[], etc.) then
-		// a code change is needed.  See api/filters/imagetag/legacy
-		// for the start of an implementation that won't use an
-		// allowlist like FsSlice, and instead walks the object looking
-		// for fields named containers or initContainers.
-		err := filtersutil.ApplyToJSON(imagetag.Filter{
+		// traverse all fields at first
+		err := filtersutil.ApplyToJSON(imagetag.LegacyFilter{
+			ImageTag: p.ImageTag,
+		}, r)
+		if err != nil {
+			return err
+		}
+		// then use user specified field specs
+		err = filtersutil.ApplyToJSON(imagetag.Filter{
 			ImageTag: p.ImageTag,
 			FsSlice:  p.FieldSpecs,
 		}, r)

plugin/builtin/imagetagtransformer/ImageTagTransformer_test.go

@@ -452,3 +452,104 @@ spec:
         name: my-image
 `)
 }
+
+func TestImageTagTransformerArbitraryPath(t *testing.T) {
+	th := kusttest_test.MakeEnhancedHarness(t).
+		PrepBuiltin("ImageTagTransformer")
+	defer th.Reset()
+
+	rm := th.LoadAndRunTransformer(`
+apiVersion: builtin
+kind: ImageTagTransformer
+metadata:
+  name: notImportantHere
+imageTag:
+  name: some.registry.io/my-image
+  newTag: "my-fixed-tag"
+`, `
+group: apps
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: deploy1
+spec:
+  template:
+    spec:
+      containers:
+      - image: some.registry.io/my-image:old-tag
+        name: my-image
+`)
+
+	th.AssertActualEqualsExpected(rm, `
+apiVersion: v1
+group: apps
+kind: Deployment
+metadata:
+  name: deploy1
+spec:
+  template:
+    spec:
+      containers:
+      - image: some.registry.io/my-image:my-fixed-tag
+        name: my-image
+`)
+}
+
+func TestImageTagTransformerInKustomization(t *testing.T) {
+	th := kusttest_test.MakeHarness(t)
+	th.WriteK("/app", `
+resources:
+- resources.yaml
+images:
+- name: old-image-name
+  newName: new-image-name
+  newTag: new-tag
+`)
+
+	th.WriteF("/app/resources.yaml", `
+apiVersion: v1
+group: apps
+kind: Deployment
+metadata:
+  name: deploy1
+spec:
+  containers:
+  - image: old-image-name
+    name: my-image
+  initContainers:
+  - image: old-image-name
+    name: my-image
+  template:
+    spec:
+      containers:
+      - image: old-image-name
+        name: my-image
+      initContainers:
+      - image: old-image-name
+        name: my-image
+`)
+
+	m := th.Run("/app", th.MakeDefaultOptions())
+	th.AssertActualEqualsExpected(m, `
+apiVersion: v1
+group: apps
+kind: Deployment
+metadata:
+  name: deploy1
+spec:
+  containers:
+  - image: new-image-name:new-tag
+    name: my-image
+  initContainers:
+  - image: new-image-name:new-tag
+    name: my-image
+  template:
+    spec:
+      containers:
+      - image: new-image-name:new-tag
+        name: my-image
+      initContainers:
+      - image: new-image-name:new-tag
+        name: my-image
+`)
+}