Keep var refernce in resources

pkg/resource/resource.go

@@ -31,8 +31,9 @@ import (
 // paired with a GenerationBehavior.
 type Resource struct {
 	ifc.Kunstructured
-	options *types.GenArgs
-	refBy   []resid.ResId
+	options     *types.GenArgs
+	refBy       []resid.ResId
+	refVarNames []string
 }
 
 func (r *Resource) KunstructEqual(o *Resource) bool {
@@ -59,6 +60,11 @@ func (r *Resource) DeepCopy() *Resource {
 		copy(refby, r.refBy)
 		rc.refBy = refby
 	}
+	if len(r.refVarNames) > 0 {
+		refVarNames := make([]string, len(r.refVarNames))
+		copy(refVarNames, r.refVarNames)
+		rc.refVarNames = refVarNames
+	}
 	return rc
 }
 
@@ -98,6 +104,16 @@ func (r *Resource) AppendRefBy(id resid.ResId) {
 	r.refBy = append(r.refBy, id)
 }
 
+// GetRefVarNames returns vars that refer to current resource
+func (r *Resource) GetRefVarNames() []string {
+	return r.refVarNames
+}
+
+// AppendRefVarName appends a name of a var into the refVar list
+func (r *Resource) AppendRefVarName(variable types.Var) {
+	r.refVarNames = append(r.refVarNames, variable.Name)
+}
+
 // Merge performs merge with other resource.
 func (r *Resource) Merge(other *Resource) {
 	r.Replace(other)

pkg/resource/resource_test.go

@@ -24,6 +24,7 @@ import (
 	"sigs.k8s.io/kustomize/pkg/gvk"
 	"sigs.k8s.io/kustomize/pkg/resid"
 	. "sigs.k8s.io/kustomize/pkg/resource"
+	"sigs.k8s.io/kustomize/pkg/types"
 )
 
 var factory = NewFactory(
@@ -122,6 +123,14 @@ func TestDeepCopy(t *testing.T) {
 		})
 	r.AppendRefBy(resid.NewResId(gvk.Gvk{Group: "somegroup", Kind: "MyKind"}, "random"))
 
+	var1 := types.Var{
+		Name: "SERVICE_ONE",
+		ObjRef: types.Target{
+			Gvk:  gvk.Gvk{Version: "v1", Kind: "Service"},
+			Name: "backendOne"},
+	}
+	r.AppendRefVarName(var1)
+
 	cr := r.DeepCopy()
 	if !reflect.DeepEqual(r, cr) {
 		t.Errorf("expected %v\nbut got%v", r, cr)