Imagetag trackable filter

api/filters/imagetag/imagetag.go

@@ -23,9 +23,17 @@ type Filter struct {
 	// FsSlice contains the FieldSpecs to locate an image field,
 	// e.g. Path: "spec/myContainers[]/image"
 	FsSlice types.FsSlice `json:"fieldSpecs,omitempty" yaml:"fieldSpecs,omitempty"`
+
+	trackableSetter filtersutil.TrackableSetter
 }
 
 var _ kio.Filter = Filter{}
+var _ kio.TrackableFilter = &Filter{}
+
+// WithMutationTracker registers a callback which will be invoked each time a field is mutated
+func (f *Filter) WithMutationTracker(callback func(key, value, tag string, node *yaml.RNode)) {
+	f.trackableSetter.WithMutationTracker(callback)
+}
 
 func (f Filter) Filter(nodes []*yaml.RNode) ([]*yaml.RNode, error) {
 	_, err := kio.FilterAll(yaml.FilterFunc(f.filter)).Filter(nodes)
@@ -40,8 +48,11 @@ func (f Filter) filter(node *yaml.RNode) (*yaml.RNode, error) {
 		return node, nil
 	}
 	if err := node.PipeE(fsslice.Filter{
-		FsSlice:  f.FsSlice,
-		SetValue: updateImageTagFn(f.ImageTag),
+		FsSlice: f.FsSlice,
+		SetValue: imageTagUpdater{
+			ImageTag:        f.ImageTag,
+			trackableSetter: f.trackableSetter,
+		}.SetImageValue,
 	}); err != nil {
 		return nil, err
 	}
@@ -59,11 +70,3 @@ func (f Filter) isOnDenyList(node *yaml.RNode) bool {
 	// https://github.com/kubernetes-sigs/kustomize/issues/890
 	return meta.Kind == `CustomResourceDefinition`
 }
-
-func updateImageTagFn(imageTag types.Image) filtersutil.SetFn {
-	return func(node *yaml.RNode) error {
-		return node.PipeE(imageTagUpdater{
-			ImageTag: imageTag,
-		})
-	}
-}

api/filters/imagetag/imagetag_test.go

@@ -10,14 +10,35 @@ import (
 	"github.com/stretchr/testify/assert"
 	filtertest "sigs.k8s.io/kustomize/api/testutils/filtertest"
 	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
 
+type setValueArg struct {
+	Key       string
+	Value     string
+	Tag       string
+	PrevValue string
+}
+
+var setValueArgs []setValueArg
+
+func setValueCallbackStub(key, value, tag string, node *yaml.RNode) {
+	setValueArgs = append(setValueArgs, setValueArg{
+		Key:       key,
+		Value:     value,
+		Tag:       tag,
+		PrevValue: node.YNode().Value,
+	})
+}
+
 func TestImageTagUpdater_Filter(t *testing.T) {
 	testCases := map[string]struct {
-		input          string
-		expectedOutput string
-		filter         Filter
-		fsSlice        types.FsSlice
+		input                string
+		expectedOutput       string
+		filter               Filter
+		fsSlice              types.FsSlice
+		setValueCallback     func(key, value, tag string, node *yaml.RNode)
+		expectedSetValueArgs []setValueArg
 	}{
 		"ignore CustomResourceDefinition": {
 			input: `
@@ -658,17 +679,108 @@ spec:
 				},
 			},
 		},
+		"mutation tracker": {
+			input: `
+group: apps
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: deploy1
+spec:
+  template:
+    spec:
+      containers:
+      - image: nginx:1.7.9
+        name: nginx-tagged
+      - image: nginx:latest
+        name: nginx-latest
+      - image: foobar:1
+        name: replaced-with-digest
+      - image: postgres:1.8.0
+        name: postgresdb
+      initContainers:
+      - image: nginx
+        name: nginx-notag
+      - image: nginx@sha256:111111111111111111
+        name: nginx-sha256
+      - image: alpine:1.8.0
+        name: init-alpine
+`,
+			expectedOutput: `
+group: apps
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: deploy1
+spec:
+  template:
+    spec:
+      containers:
+      - image: busybox:v3
+        name: nginx-tagged
+      - image: busybox:v3
+        name: nginx-latest
+      - image: foobar:1
+        name: replaced-with-digest
+      - image: postgres:1.8.0
+        name: postgresdb
+      initContainers:
+      - image: busybox:v3
+        name: nginx-notag
+      - image: busybox:v3
+        name: nginx-sha256
+      - image: alpine:1.8.0
+        name: init-alpine
+`,
+			filter: Filter{
+				ImageTag: types.Image{
+					Name:    "nginx",
+					NewName: "busybox",
+					NewTag:  "v3",
+				},
+			},
+			fsSlice: []types.FieldSpec{
+				{
+					Path: "spec/template/spec/containers[]/image",
+				},
+				{
+					Path: "spec/template/spec/initContainers[]/image",
+				},
+			},
+			setValueCallback: setValueCallbackStub,
+			expectedSetValueArgs: []setValueArg{
+				{
+					Value:     "busybox:v3",
+					PrevValue: "nginx:1.7.9",
+				},
+				{
+					Value:     "busybox:v3",
+					PrevValue: "nginx:latest",
+				},
+				{
+					Value:     "busybox:v3",
+					PrevValue: "nginx",
+				},
+				{
+					Value:     "busybox:v3",
+					PrevValue: "nginx@sha256:111111111111111111",
+				},
+			},
+		},
 	}
 
 	for tn, tc := range testCases {
+		setValueArgs = nil
 		t.Run(tn, func(t *testing.T) {
 			filter := tc.filter
+			filter.WithMutationTracker(tc.setValueCallback)
 			filter.FsSlice = tc.fsSlice
 			if !assert.Equal(t,
 				strings.TrimSpace(tc.expectedOutput),
 				strings.TrimSpace(filtertest.RunFilter(t, tc.input, filter))) {
 				t.FailNow()
 			}
+			assert.Equal(t, tc.expectedSetValueArgs, setValueArgs)
 		})
 	}
 }

api/filters/imagetag/updater.go

@@ -4,6 +4,7 @@
 package imagetag
 
 import (
+	"sigs.k8s.io/kustomize/api/filters/filtersutil"
 	"sigs.k8s.io/kustomize/api/image"
 	"sigs.k8s.io/kustomize/api/types"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
@@ -13,19 +14,20 @@ import (
 // that will update the value of the yaml node based on the provided
 // ImageTag if the current value matches the format of an image reference.
 type imageTagUpdater struct {
-	Kind     string      `yaml:"kind,omitempty"`
-	ImageTag types.Image `yaml:"imageTag,omitempty"`
+	Kind            string      `yaml:"kind,omitempty"`
+	ImageTag        types.Image `yaml:"imageTag,omitempty"`
+	trackableSetter filtersutil.TrackableSetter
 }
 
-func (u imageTagUpdater) Filter(rn *yaml.RNode) (*yaml.RNode, error) {
+func (u imageTagUpdater) SetImageValue(rn *yaml.RNode) error {
 	if err := yaml.ErrorIfInvalid(rn, yaml.ScalarNode); err != nil {
-		return nil, err
+		return err
 	}
 
 	value := rn.YNode().Value
 
 	if !image.IsImageMatched(value, u.ImageTag.Name) {
-		return rn, nil
+		return nil
 	}
 
 	name, tag := image.Split(value)
@@ -39,5 +41,12 @@ func (u imageTagUpdater) Filter(rn *yaml.RNode) (*yaml.RNode, error) {
 		tag = "@" + u.ImageTag.Digest
 	}
 
-	return rn.Pipe(yaml.FieldSetter{StringValue: name + tag})
+	return u.trackableSetter.SetScalar(name + tag)(rn)
+}
+
+func (u imageTagUpdater) Filter(rn *yaml.RNode) (*yaml.RNode, error) {
+	if err := u.SetImageValue(rn); err != nil {
+		return nil, err
+	}
+	return rn, nil
 }