deprecate enable-managedby-label flag in favor of a field

api/krusty/kustomizer.go

@@ -10,6 +10,7 @@ import (
 	"sigs.k8s.io/kustomize/api/internal/builtins"
 	pLdr "sigs.k8s.io/kustomize/api/internal/plugins/loader"
 	"sigs.k8s.io/kustomize/api/internal/target"
+	"sigs.k8s.io/kustomize/api/internal/utils"
 	"sigs.k8s.io/kustomize/api/konfig"
 	fLdr "sigs.k8s.io/kustomize/api/loader"
 	"sigs.k8s.io/kustomize/api/provenance"
@@ -95,7 +96,7 @@ func (b *Kustomizer) Run(
 			return nil, err
 		}
 	}
-	if b.options.AddManagedbyLabel {
+	if b.options.AddManagedbyLabel || utils.StringSliceContains(kt.Kustomization().BuildMetadata, types.ManagedByLabelOption) {
 		t := builtins.LabelTransformerPlugin{
 			Labels: map[string]string{
 				konfig.ManagedbyLabelKey: fmt.Sprintf("kustomize-%s", provenance.GetProvenance().Semver()),

api/krusty/managedbylabel_test.go

@@ -9,7 +9,46 @@ import (
 	kusttest_test "sigs.k8s.io/kustomize/api/testutils/kusttest"
 )
 
+const expected = `apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    app.kubernetes.io/managed-by: kustomize-v444.333.222
+  name: myService
+spec:
+  ports:
+  - port: 7002
+`
+
 func TestAddManagedbyLabel(t *testing.T) {
+	tests := []struct {
+		kustFile      string
+		managedByFlag bool
+		expected      string
+	}{
+		{
+			kustFile: `
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+- service.yaml
+`,
+			managedByFlag: true,
+			expected:      expected,
+		},
+		{
+			kustFile: `
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+- service.yaml
+buildMetadata: [managedByLabel]
+`,
+			managedByFlag: false,
+			expected:      expected,
+		},
+	}
+	for _, tc := range tests {
 		th := kusttest_test.MakeHarness(t)
 		th.WriteF("service.yaml", `
 apiVersion: v1
@@ -20,24 +59,10 @@ spec:
   ports:
   - port: 7002
 `)
-	th.WriteK(".", `
+		th.WriteK(".", tc.kustFile)
-apiVersion: kustomize.config.k8s.io/v1beta1
-kind: Kustomization
-resources:
-- service.yaml
-`)
 		options := th.MakeDefaultOptions()
-	options.AddManagedbyLabel = true
+		options.AddManagedbyLabel = tc.managedByFlag
 		m := th.Run(".", options)
-	th.AssertActualEqualsExpected(m, `
+		th.AssertActualEqualsExpected(m, tc.expected)
-apiVersion: v1
+	}
-kind: Service
-metadata:
-  labels:
-    app.kubernetes.io/managed-by: kustomize-v444.333.222
-  name: myService
-spec:
-  ports:
-  - port: 7002
-`)
 }

api/types/kustomization.go

@@ -17,7 +17,9 @@ const (
 	ComponentVersion      = "kustomize.config.k8s.io/v1alpha1"
 	ComponentKind         = "Component"
 	MetadataNamespacePath = "metadata/namespace"
+
 	OriginAnnotations    = "originAnnotations"
+	ManagedByLabelOption = "managedByLabel"
 )
 
 // Kustomization holds the information needed to generate customized k8s api resources.

kustomize/commands/build/build.go

@@ -104,6 +104,8 @@ func NewCmdBuild(
 	AddFlagEnablePlugins(cmd.Flags())
 	AddFlagReorderOutput(cmd.Flags())
 	AddFlagEnableManagedbyLabel(cmd.Flags())
+	cmd.Flags().MarkDeprecated(managedByFlag,
+		"The flag `enable-managedby-label` has been deprecated. Use the `managedByLabel` option in the `buildMetadata` field instead.")
 	AddFlagEnableHelm(cmd.Flags())
 	return cmd
 }

kustomize/commands/build/flagaddmanagedby.go

@@ -10,10 +10,12 @@ import (
 	"sigs.k8s.io/kustomize/api/konfig"
 )
 
+const managedByFlag = "enable-managedby-label"
+
 func AddFlagEnableManagedbyLabel(set *pflag.FlagSet) {
 	set.BoolVar(
 		&theFlags.enable.managedByLabel,
-		"enable-managedby-label",
+		managedByFlag,
 		false,
 		`enable adding `+konfig.ManagedbyLabelKey)
 }