From 8bf98dd255c538898728c47f186a4d595e376b26 Mon Sep 17 00:00:00 2001
From: Phillip Wittrock <pwittroc@google.com>
Date: Tue, 29 Oct 2019 16:41:45 -0700
Subject: [PATCH] Support for ignoring specific Resources via annotation.

Resources annotated with `config.kubernetes.io/local-config` will be ignored by Kustomize
---
 api/k8sdeps/kunstruct/factory.go      | 20 +++++++++++++++++++-
 api/k8sdeps/kunstruct/factory_test.go | 19 +++++++++++++++++++
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/api/k8sdeps/kunstruct/factory.go b/api/k8sdeps/kunstruct/factory.go
index 36e24aea0..ee3cd4597 100644
--- a/api/k8sdeps/kunstruct/factory.go
+++ b/api/k8sdeps/kunstruct/factory.go
@@ -52,7 +52,9 @@ func (kf *KunstructuredFactoryImpl) SliceFromBytes(
 			if err != nil {
 				return nil, err
 			}
-			result = append(result, &UnstructAdapter{Unstructured: out})
+			if !kf.skipResource(out) {
+				result = append(result, &UnstructAdapter{Unstructured: out})
+			}
 		}
 	}
 	if err != io.EOF {
@@ -116,6 +118,22 @@ func (kf *KunstructuredFactoryImpl) validate(u unstructured.Unstructured) error
 	return nil
 }
 
+// nonKustomizableResourceAnnotation if set on a Resource will cause Kustomize to
+// ignore the Resource rather than Kustomize it.
+const ignoredByKustomizeResourceAnnotation = "config.kubernetes.io/local-config"
+
+// skipResource returns true if the Resource should not be accumulated
+func (kf *KunstructuredFactoryImpl) skipResource(u unstructured.Unstructured) bool {
+	an := u.GetAnnotations()
+	if an == nil {
+		// annotation unset
+		return false
+	}
+	// check if the Resource has opt-ed out of kustomize
+	_, found := an[ignoredByKustomizeResourceAnnotation]
+	return found
+}
+
 func checkListItemNil(in interface{}) (bool, string) {
 	switch v := in.(type) {
 	case map[string]interface{}:
diff --git a/api/k8sdeps/kunstruct/factory_test.go b/api/k8sdeps/kunstruct/factory_test.go
index b52a73a35..97d2203b7 100644
--- a/api/k8sdeps/kunstruct/factory_test.go
+++ b/api/k8sdeps/kunstruct/factory_test.go
@@ -105,6 +105,25 @@ metadata:
 			expectedOut: []ifc.Kunstructured{testConfigMap, testConfigMap},
 			expectedErr: false,
 		},
+		{
+			name: "localConfigYaml",
+			input: []byte(`
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: winnie-skip
+  annotations:
+    # this annotation causes the Resource to be ignored by kustomize
+    config.kubernetes.io/local-config: ""
+---
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: winnie 
+`),
+			expectedOut: []ifc.Kunstructured{testConfigMap},
+			expectedErr: false,
+		},
 		{
 			name: "garbageInOneOfTwoObjects",
 			input: []byte(`