Add different behavior for configmaps in overlay

pkg/apis/manifest/v1alpha1/types.go

@@ -132,6 +132,12 @@ type ConfigMap struct {
 	// hash(content of configmap).
 	Name string `json:"name,omitempty" yaml:"name,omitempty"`
 
+	// Behavior of the configmap, must be one of create, merge and replace
+	// 'create': create a new one;
+	// 'replace': replace the existing one;
+	// 'merge': merge the existing one.
+	Behavior string `json:"behavior,omitempty" yaml:"behavior,omitempty"`
+
 	// DataSources for configmap.
 	DataSources `json:",inline,omitempty" yaml:",inline,omitempty"`
 }

pkg/kinflate/app/application.go

@@ -33,6 +33,8 @@ import (
 type Application interface {
 	// Resources computes and returns the resources for the app.
 	Resources() (resource.ResourceCollection, error)
+	// SemiResources computes and returns the resources without name hash and name reference for the app
+	SemiResources() (resource.ResourceCollection, error)
 	// RawResources computes and returns the raw resources from the manifest.
 	// It contains resources from 1) untransformed resources from current manifest 2) transformed resources from sub packages
 	RawResources() (resource.ResourceCollection, error)
@@ -63,9 +65,28 @@ func New(loader loader.Loader) (Application, error) {
 }
 
 // Resources computes and returns the resources from the manifest.
+// The namehashing for configmap/secrets and resolving name reference is only done
+// in the most top overlay once at the end of getting resources.
 func (a *applicationImpl) Resources() (resource.ResourceCollection, error) {
+	res, err := a.SemiResources()
+	if err != nil {
+		return nil, err
+	}
+	t, err := a.getHashAndReferenceTransformer()
+	if err != nil {
+		return nil, err
+	}
+	err = t.Transform(res)
+	if err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+// SemiResources computes and returns the resources without name hash and name reference for the app
+func (a *applicationImpl) SemiResources() (resource.ResourceCollection, error) {
 	errs := &interror.ManifestErrors{}
-	raw, err := a.RawResources()
+	raw, err := a.rawResources()
 	if err != nil {
 		errs.Append(err)
 	}
@@ -82,9 +103,8 @@ func (a *applicationImpl) Resources() (resource.ResourceCollection, error) {
 	if err != nil {
 		return nil, err
 	}
-	// Only append hash for generated configmaps and secrets.
+
-	nht := transformers.NewNameHashTransformer()
+	allRes, err := resource.MergeWithOverride(raw, res)
-	err = nht.Transform(res)
 	if err != nil {
 		return nil, err
 	}
@@ -98,37 +118,11 @@ func (a *applicationImpl) Resources() (resource.ResourceCollection, error) {
 		return nil, errs
 	}
 
-	// Reindex the Raw Resources (resources from sub package and resources field of this package).
+	t, err := a.getTransformer(patches)
-	// raw is a ResourceCollection (map) from <GVK, original name> to object with the transformed name.
-	// transRaw is a ResourceCollection (map) from <GVK, transformed name> to object with the transformed name.
-	transRaw := reindexResourceCollection(raw)
-	// allRes contains the resources that are indexed by the original names (old names).
-	// allTransRes contains the resources that are indexed by the transformed names (new names).
-	// allRes and allTransRes point to the same set of objects with new names.
-	allTransRes, err := resource.Merge(res, transRaw)
 	if err != nil {
 		return nil, err
 	}
-	allRes, err := resource.Merge(res, raw)
+	err = t.Transform(allRes)
-	if err != nil {
-		return nil, err
-	}
-
-	ot, err := transformers.NewOverlayTransformer(patches)
-	if err != nil {
-		return nil, err
-	}
-	// Overlay transformer uses the ResourceCollection indexed by the original names.
-	err = ot.Transform(allRes)
-	if err != nil {
-		return nil, err
-	}
-
-	t, err := a.getTransformer()
-	if err != nil {
-		return nil, err
-	}
-	err = t.Transform(allTransRes)
 	if err != nil {
 		return nil, err
 	}
@@ -137,7 +131,25 @@ func (a *applicationImpl) Resources() (resource.ResourceCollection, error) {
 }
 
 // RawResources computes and returns the raw resources from the manifest.
+// The namehashing for configmap/secrets and resolving name reference is only done
+// in the most top overlay once at the end of getting resources.
 func (a *applicationImpl) RawResources() (resource.ResourceCollection, error) {
+	res, err := a.rawResources()
+	if err != nil {
+		return nil, err
+	}
+	t, err := a.getHashAndReferenceTransformer()
+	if err != nil {
+		return nil, err
+	}
+	err = t.Transform(res)
+	if err != nil {
+		return nil, err
+	}
+	return res, nil
+}
+
+func (a *applicationImpl) rawResources() (resource.ResourceCollection, error) {
 	subAppResources, errs := a.subAppResources()
 	resources, err := resource.NewFromResources(a.loader, a.manifest.Resources)
 	if err != nil {
@@ -166,7 +178,7 @@ func (a *applicationImpl) subAppResources() (resource.ResourceCollection, *inter
 			continue
 		}
 		// Gather all transformed resources from subpackages.
-		subAppResources, err := subapp.Resources()
+		subAppResources, err := subapp.SemiResources()
 		if err != nil {
 			errs.Append(err)
 			continue
@@ -181,13 +193,19 @@ func (a *applicationImpl) subAppResources() (resource.ResourceCollection, *inter
 }
 
 // getTransformer generates the following transformers:
-// 1) name prefix
+// 1) apply overlay
-// 2) apply labels
+// 2) name prefix
-// 3) apply annotations
+// 3) apply labels
-// 4) update name reference
+// 4) apply annotations
-func (a *applicationImpl) getTransformer() (transformers.Transformer, error) {
+func (a *applicationImpl) getTransformer(patches []*resource.Resource) (transformers.Transformer, error) {
 	ts := []transformers.Transformer{}
 
+	ot, err := transformers.NewOverlayTransformer(patches)
+	if err != nil {
+		return nil, err
+	}
+	ts = append(ts, ot)
+
 	npt, err := transformers.NewDefaultingNamePrefixTransformer(string(a.manifest.NamePrefix))
 	if err != nil {
 		return nil, err
@@ -206,6 +224,17 @@ func (a *applicationImpl) getTransformer() (transformers.Transformer, error) {
 	}
 	ts = append(ts, at)
 
+	return transformers.NewMultiTransformer(ts), nil
+}
+
+// getHashAndReferenceTransformer generates the following transformers:
+// 1) name hash for configmap and secrests
+// 2) apply name reference
+func (a *applicationImpl) getHashAndReferenceTransformer() (transformers.Transformer, error) {
+	ts := []transformers.Transformer{}
+	nht := transformers.NewNameHashTransformer()
+	ts = append(ts, nht)
+
 	nrt, err := transformers.NewDefaultingNameReferenceTransformer()
 	if err != nil {
 		return nil, err
@@ -214,17 +243,6 @@ func (a *applicationImpl) getTransformer() (transformers.Transformer, error) {
 	return transformers.NewMultiTransformer(ts), nil
 }
 
-// reindexResourceCollection returns a new instance of ResourceCollection which
-// is indexed using the new name in the object.
-func reindexResourceCollection(rc resource.ResourceCollection) resource.ResourceCollection {
-	result := resource.ResourceCollection{}
-	for gvkn, res := range rc {
-		gvkn.Name = res.Data.GetName()
-		result[gvkn] = res
-	}
-	return result
-}
-
 func unmarshal(y []byte, o interface{}) error {
 	j, err := yaml.YAMLToJSON(y)
 	if err != nil {

pkg/kinflate/app/application_test.go

@@ -121,7 +121,7 @@ func TestResources(t *testing.T) {
 					"apiVersion": "v1",
 					"kind":       "ConfigMap",
 					"metadata": map[string]interface{}{
-						"name": "foo-literalConfigMap-h25f8c59t4",
+						"name": "foo-literalConfigMap-mc92bgcbh5",
 						"labels": map[string]interface{}{
 							"app": "nginx",
 						},
@@ -146,7 +146,7 @@ func TestResources(t *testing.T) {
 					"apiVersion": "v1",
 					"kind":       "Secret",
 					"metadata": map[string]interface{}{
-						"name": "foo-secret-2c9kh7fh8t",
+						"name": "foo-secret-877fcfhgt5",
 						"labels": map[string]interface{}{
 							"app": "nginx",
 						},

pkg/kinflate/commands/testdata/testcase-simple/expected.diff

@@ -39,12 +39,12 @@ diff -u -N /tmp/noop/extensions_v1beta1_Deployment_mungebot.yaml /tmp/transforme
 +          valueFrom:
 +            configMapKeyRef:
 +              key: somekey
-+              name: test-infra-app-env-hf26mf2f2f
++              name: test-infra-app-env-bh449c299k
 +        - name: BAR
 +          valueFrom:
 +            secretKeyRef:
 +              key: somekey
-+              name: test-infra-app-tls-4d47hbbh9m
++              name: test-infra-app-tls-6hkmhf2224
          - name: foo
            value: bar
 -        image: nginx
@@ -56,9 +56,9 @@ diff -u -N /tmp/noop/extensions_v1beta1_Deployment_mungebot.yaml /tmp/transforme
 +        - configMapRef:
 +            name: someConfigMap
 +        - configMapRef:
-+            name: test-infra-app-env-hf26mf2f2f
++            name: test-infra-app-env-bh449c299k
 +        - secretRef:
-+            name: test-infra-app-tls-4d47hbbh9m
++            name: test-infra-app-tls-6hkmhf2224
 +        image: busybox
 +        name: busybox
 +        volumeMounts:
@@ -68,11 +68,11 @@ diff -u -N /tmp/noop/extensions_v1beta1_Deployment_mungebot.yaml /tmp/transforme
 +          name: app-tls
 +      volumes:
 +      - configMap:
-+          name: test-infra-app-env-hf26mf2f2f
++          name: test-infra-app-env-bh449c299k
 +        name: app-env
 +      - name: app-tls
 +        secret:
-+          secretName: test-infra-app-tls-4d47hbbh9m
++          secretName: test-infra-app-tls-6hkmhf2224
 diff -u -N /tmp/noop/v1_ConfigMap_app-config.yaml /tmp/transformed/v1_ConfigMap_app-config.yaml
 --- /tmp/noop/v1_ConfigMap_app-config.yaml	YYYY-MM-DD HH:MM:SS
 +++ /tmp/transformed/v1_ConfigMap_app-config.yaml	YYYY-MM-DD HH:MM:SS
@@ -91,7 +91,7 @@ diff -u -N /tmp/noop/v1_ConfigMap_app-config.yaml /tmp/transformed/v1_ConfigMap_
 +    app: mungebot
 +    org: kubernetes
 +    repo: test-infra
-+  name: test-infra-app-config-ht8ck65bcg
++  name: test-infra-app-config-hf5424hg8g
 diff -u -N /tmp/noop/v1_ConfigMap_app-env.yaml /tmp/transformed/v1_ConfigMap_app-env.yaml
 --- /tmp/noop/v1_ConfigMap_app-env.yaml	YYYY-MM-DD HH:MM:SS
 +++ /tmp/transformed/v1_ConfigMap_app-env.yaml	YYYY-MM-DD HH:MM:SS
@@ -109,7 +109,7 @@ diff -u -N /tmp/noop/v1_ConfigMap_app-env.yaml /tmp/transformed/v1_ConfigMap_app
 +    app: mungebot
 +    org: kubernetes
 +    repo: test-infra
-+  name: test-infra-app-env-hf26mf2f2f
++  name: test-infra-app-env-bh449c299k
 diff -u -N /tmp/noop/v1_Secret_app-tls.yaml /tmp/transformed/v1_Secret_app-tls.yaml
 --- /tmp/noop/v1_Secret_app-tls.yaml	YYYY-MM-DD HH:MM:SS
 +++ /tmp/transformed/v1_Secret_app-tls.yaml	YYYY-MM-DD HH:MM:SS
@@ -127,7 +127,7 @@ diff -u -N /tmp/noop/v1_Secret_app-tls.yaml /tmp/transformed/v1_Secret_app-tls.y
 +    app: mungebot
 +    org: kubernetes
 +    repo: test-infra
-+  name: test-infra-app-tls-4d47hbbh9m
++  name: test-infra-app-tls-6hkmhf2224
 +type: kubernetes.io/tls
 diff -u -N /tmp/noop/v1_Service_mungebot-service.yaml /tmp/transformed/v1_Service_mungebot-service.yaml
 --- /tmp/noop/v1_Service_mungebot-service.yaml	YYYY-MM-DD HH:MM:SS

pkg/kinflate/commands/testdata/testcase-simple/expected.yaml

@@ -12,7 +12,7 @@ metadata:
     app: mungebot
     org: kubernetes
     repo: test-infra
-  name: test-infra-app-config-ht8ck65bcg
+  name: test-infra-app-config-hf5424hg8g
 ---
 apiVersion: v1
 data:
@@ -27,7 +27,7 @@ metadata:
     app: mungebot
     org: kubernetes
     repo: test-infra
-  name: test-infra-app-env-hf26mf2f2f
+  name: test-infra-app-env-bh449c299k
 ---
 apiVersion: v1
 data:
@@ -42,7 +42,7 @@ metadata:
     app: mungebot
     org: kubernetes
     repo: test-infra
-  name: test-infra-app-tls-4d47hbbh9m
+  name: test-infra-app-tls-6hkmhf2224
 type: kubernetes.io/tls
 ---
 apiVersion: v1
@@ -103,12 +103,12 @@ spec:
           valueFrom:
             configMapKeyRef:
               key: somekey
-              name: test-infra-app-env-hf26mf2f2f
+              name: test-infra-app-env-bh449c299k
         - name: BAR
           valueFrom:
             secretKeyRef:
               key: somekey
-              name: test-infra-app-tls-4d47hbbh9m
+              name: test-infra-app-tls-6hkmhf2224
         - name: foo
           value: bar
         image: nginx:1.7.9
@@ -119,9 +119,9 @@ spec:
         - configMapRef:
             name: someConfigMap
         - configMapRef:
-            name: test-infra-app-env-hf26mf2f2f
+            name: test-infra-app-env-bh449c299k
         - secretRef:
-            name: test-infra-app-tls-4d47hbbh9m
+            name: test-infra-app-tls-6hkmhf2224
         image: busybox
         name: busybox
         volumeMounts:
@@ -131,8 +131,8 @@ spec:
           name: app-tls
       volumes:
       - configMap:
-          name: test-infra-app-env-hf26mf2f2f
+          name: test-infra-app-env-bh449c299k
         name: app-env
       - name: app-tls
         secret:
-          secretName: test-infra-app-tls-4d47hbbh9m
+          secretName: test-infra-app-tls-6hkmhf2224

pkg/kinflate/commands/testdata/testcase-single-overlay/expected.diff

@@ -1,14 +1,15 @@
 diff -u -N /tmp/noop/apps_v1beta2_Deployment_nginx.yaml /tmp/transformed/apps_v1beta2_Deployment_nginx.yaml
 --- /tmp/noop/apps_v1beta2_Deployment_nginx.yaml	YYYY-MM-DD HH:MM:SS
 +++ /tmp/transformed/apps_v1beta2_Deployment_nginx.yaml	YYYY-MM-DD HH:MM:SS
-@@ -5,13 +5,15 @@
+@@ -5,23 +5,26 @@
      note: This is a test annotation
    labels:
      app: mynginx
 +    env: staging
      org: example.com
-     team: foo
+-    team: foo
 -  name: team-foo-nginx
++    team: override-foo
 +  name: staging-team-foo-nginx
  spec:
    selector:
@@ -16,16 +17,21 @@ diff -u -N /tmp/noop/apps_v1beta2_Deployment_nginx.yaml /tmp/transformed/apps_v1
        app: mynginx
 +      env: staging
        org: example.com
-       team: foo
+-      team: foo
++      team: override-foo
    template:
-@@ -20,6 +22,7 @@
+     metadata:
+       annotations:
          note: This is a test annotation
        labels:
          app: mynginx
 +        env: staging
          org: example.com
-         team: foo
+-        team: foo
++        team: override-foo
      spec:
+       containers:
+       - image: nginx
 @@ -30,8 +33,12 @@
          - mountPath: /tmp/ps
            name: nginx-persistent-storage
@@ -35,28 +41,37 @@ diff -u -N /tmp/noop/apps_v1beta2_Deployment_nginx.yaml /tmp/transformed/apps_v1
 +          pdName: nginx-persistent-storage
          name: nginx-persistent-storage
        - configMap:
--          name: team-foo-configmap-in-base-72t84tc949
+-          name: team-foo-configmap-in-base-bbdmdh7m8t
-+          name: staging-configmap-in-overlay-h4hbb8fckf
++          name: staging-configmap-in-overlay-k7cbc75tg8
 +        name: configmap-in-overlay
 +      - configMap:
-+          name: staging-team-foo-configmap-in-base-72t84tc949
++          name: staging-team-foo-configmap-in-base-gh9d7t85gb
          name: configmap-in-base
 diff -u -N /tmp/noop/v1_ConfigMap_configmap-in-base.yaml /tmp/transformed/v1_ConfigMap_configmap-in-base.yaml
 --- /tmp/noop/v1_ConfigMap_configmap-in-base.yaml	YYYY-MM-DD HH:MM:SS
 +++ /tmp/transformed/v1_ConfigMap_configmap-in-base.yaml	YYYY-MM-DD HH:MM:SS
+@@ -1,6 +1,6 @@
+ apiVersion: v1
+ data:
+-  foo: bar
++  foo: override-bar
+ kind: ConfigMap
+ metadata:
+   annotations:
 @@ -8,6 +8,7 @@
    creationTimestamp: null
    labels:
      app: mynginx
 +    env: staging
      org: example.com
-     team: foo
+-    team: foo
--  name: team-foo-configmap-in-base-72t84tc949
+-  name: team-foo-configmap-in-base-bbdmdh7m8t
-+  name: staging-team-foo-configmap-in-base-72t84tc949
++    team: override-foo
++  name: staging-team-foo-configmap-in-base-gh9d7t85gb
 diff -u -N /tmp/noop/v1_ConfigMap_configmap-in-overlay.yaml /tmp/transformed/v1_ConfigMap_configmap-in-overlay.yaml
 --- /tmp/noop/v1_ConfigMap_configmap-in-overlay.yaml	YYYY-MM-DD HH:MM:SS
 +++ /tmp/transformed/v1_ConfigMap_configmap-in-overlay.yaml	YYYY-MM-DD HH:MM:SS
-@@ -0,0 +1,9 @@
+@@ -0,0 +1,10 @@
 +apiVersion: v1
 +data:
 +  hello: world
@@ -65,7 +80,8 @@ diff -u -N /tmp/noop/v1_ConfigMap_configmap-in-overlay.yaml /tmp/transformed/v1_
 +  creationTimestamp: null
 +  labels:
 +    env: staging
-+  name: staging-configmap-in-overlay-h4hbb8fckf
++    team: override-foo
++  name: staging-configmap-in-overlay-k7cbc75tg8
 diff -u -N /tmp/noop/v1_Service_nginx.yaml /tmp/transformed/v1_Service_nginx.yaml
 --- /tmp/noop/v1_Service_nginx.yaml	YYYY-MM-DD HH:MM:SS
 +++ /tmp/transformed/v1_Service_nginx.yaml	YYYY-MM-DD HH:MM:SS
@@ -75,8 +91,9 @@ diff -u -N /tmp/noop/v1_Service_nginx.yaml /tmp/transformed/v1_Service_nginx.yam
      app: mynginx
 +    env: staging
      org: example.com
-     team: foo
+-    team: foo
 -  name: team-foo-nginx
++    team: override-foo
 +  name: staging-team-foo-nginx
  spec:
    ports:
@@ -85,4 +102,5 @@ diff -u -N /tmp/noop/v1_Service_nginx.yaml /tmp/transformed/v1_Service_nginx.yam
      app: mynginx
 +    env: staging
      org: example.com
-     team: foo
+-    team: foo
++    team: override-foo

pkg/kinflate/commands/testdata/testcase-single-overlay/expected.yaml

@@ -1,6 +1,6 @@
 apiVersion: v1
 data:
-  foo: bar
+  foo: override-bar
 kind: ConfigMap
 metadata:
   annotations:
@@ -10,8 +10,8 @@ metadata:
     app: mynginx
     env: staging
     org: example.com
-    team: foo
+    team: override-foo
-  name: staging-team-foo-configmap-in-base-72t84tc949
+  name: staging-team-foo-configmap-in-base-gh9d7t85gb
 ---
 apiVersion: v1
 data:
@@ -21,7 +21,8 @@ metadata:
   creationTimestamp: null
   labels:
     env: staging
-  name: staging-configmap-in-overlay-h4hbb8fckf
+    team: override-foo
+  name: staging-configmap-in-overlay-k7cbc75tg8
 ---
 apiVersion: v1
 kind: Service
@@ -32,7 +33,7 @@ metadata:
     app: mynginx
     env: staging
     org: example.com
-    team: foo
+    team: override-foo
   name: staging-team-foo-nginx
 spec:
   ports:
@@ -41,7 +42,7 @@ spec:
     app: mynginx
     env: staging
     org: example.com
-    team: foo
+    team: override-foo
 ---
 apiVersion: apps/v1beta2
 kind: Deployment
@@ -52,7 +53,7 @@ metadata:
     app: mynginx
     env: staging
     org: example.com
-    team: foo
+    team: override-foo
   name: staging-team-foo-nginx
 spec:
   selector:
@@ -60,7 +61,7 @@ spec:
       app: mynginx
       env: staging
       org: example.com
-      team: foo
+      team: override-foo
   template:
     metadata:
       annotations:
@@ -69,7 +70,7 @@ spec:
         app: mynginx
         env: staging
         org: example.com
-        team: foo
+        team: override-foo
     spec:
       containers:
       - image: nginx
@@ -82,8 +83,8 @@ spec:
           pdName: nginx-persistent-storage
         name: nginx-persistent-storage
       - configMap:
-          name: staging-configmap-in-overlay-h4hbb8fckf
+          name: staging-configmap-in-overlay-k7cbc75tg8
         name: configmap-in-overlay
       - configMap:
-          name: staging-team-foo-configmap-in-base-72t84tc949
+          name: staging-team-foo-configmap-in-base-gh9d7t85gb
         name: configmap-in-base

pkg/kinflate/commands/testdata/testcase-single-overlay/in/overlay/Kube-manifest.yaml

@@ -5,6 +5,7 @@ metadata:
 namePrefix: staging-
 objectLabels:
   env: staging
+  team: override-foo
 patches:
   - deployment.yaml
 bases:
@@ -13,3 +14,7 @@ configmaps:
   - name: configmap-in-overlay
     literals:
       - hello=world
+  - name: configmap-in-base
+    behavior: replace
+    literals:
+      - foo=override-bar

pkg/kinflate/constants/constants.go

@@ -19,3 +19,8 @@ package constants
 // KubeManifestFileName is the Well-Known File Name for a kubernetes app manifest.
 const KubeManifestSuffix = ".yaml"
 const KubeManifestFileName = "Kube-manifest" + KubeManifestSuffix
+
+// Configmap behaviors
+const CreateBehavior = "create"
+const ReplaceBehavior = "replace"
+const MergeBehavior = "merge"

pkg/kinflate/resource/configmap.go

@@ -37,7 +37,7 @@ func newFromConfigMap(l loader.Loader, cm manifest.ConfigMap) (*Resource, error)
 	if err != nil {
 		return nil, err
 	}
-	return &Resource{Data: data}, nil
+	return &Resource{Data: data, Behavior: cm.Behavior}, nil
 }
 
 func makeConfigMap(l loader.Loader, cm manifest.ConfigMap) (*corev1.ConfigMap, error) {

pkg/kinflate/resource/resource.go

@@ -27,7 +27,8 @@ import (
 // Resource represents a Kubernetes Resource Object for ex. Deployment, Server
 // ConfigMap etc.
 type Resource struct {
-	Data *unstructured.Unstructured
+	Data     *unstructured.Unstructured
+	Behavior string
 }
 
 // GVKN returns Group/Version/Kind/Name for the resource.

pkg/kinflate/resource/util.go

@@ -23,6 +23,7 @@ import (
 
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	k8syaml "k8s.io/apimachinery/pkg/util/yaml"
+	"k8s.io/kubectl/pkg/kinflate/constants"
 )
 
 // decode decodes a list of objects in byte array format
@@ -90,3 +91,75 @@ func Merge(rcs ...ResourceCollection) (ResourceCollection, error) {
 
 	return all, nil
 }
+
+// MergeWithOverride will merge all of the entries in the slice of ResourceCollection with Override
+// If there is already an entry with the same GVKN exists, different actions are performed according to value of Behavior field
+// 'create': create a new one;
+// 'replace': replace the data only; keep the labels and annotations
+// 'merge': merge the data; keep the labels and annotations
+func MergeWithOverride(rcs ...ResourceCollection) (ResourceCollection, error) {
+	all := ResourceCollection{}
+
+	for _, rc := range rcs {
+		for gvkn, obj := range rc {
+			if _, found := all[gvkn]; found {
+				switch obj.Behavior {
+				case "", constants.CreateBehavior:
+					return nil, fmt.Errorf("Create an existing gvkn %#v is not allowed", gvkn)
+				case constants.ReplaceBehavior:
+					obj.replace(all[gvkn])
+					all[gvkn] = obj
+				case constants.MergeBehavior:
+					obj.merge(all[gvkn])
+					all[gvkn] = obj
+				default:
+					return nil, fmt.Errorf("The behavior of %#v must be one of merge and replace since it already exists in the base", gvkn)
+				}
+			} else {
+				switch obj.Behavior {
+				case "", constants.CreateBehavior:
+					all[gvkn] = obj
+				case constants.MergeBehavior, constants.ReplaceBehavior:
+					return nil, fmt.Errorf("No merge or replace is allowed for non existing gvkn %#v", gvkn)
+				default:
+					return nil, fmt.Errorf("The behavior of %#v must be create since it doesn't exist", gvkn)
+				}
+			}
+		}
+	}
+	return all, nil
+}
+func (r *Resource) replace(other *Resource) {
+	r.Data.SetLabels(mergeMap(other.Data.GetLabels(), r.Data.GetLabels()))
+	r.Data.SetAnnotations(mergeMap(other.Data.GetAnnotations(), r.Data.GetAnnotations()))
+	r.Data.SetName(other.Data.GetName())
+}
+
+func (r *Resource) merge(other *Resource) {
+	r.replace(other)
+	mergeConfigmap(r.Data.Object, other.Data.Object, r.Data.Object)
+}
+
+func mergeMap(maps ...map[string]string) map[string]string {
+	mergedMap := map[string]string{}
+	for _, m := range maps {
+		for key, value := range m {
+			mergedMap[key] = value
+		}
+	}
+	return mergedMap
+}
+
+// TODO: Add BinaryData once we sync to new k8s.io/api
+func mergeConfigmap(mergedTo map[string]interface{}, maps ...map[string]interface{}) {
+	mergedMap := map[string]interface{}{}
+	for _, m := range maps {
+		datamap, ok := m["data"].(map[string]interface{})
+		if ok {
+			for key, value := range datamap {
+				mergedMap[key] = value
+			}
+		}
+	}
+	mergedTo["data"] = mergedMap
+}