fix: updating expansion templates to add owner ref in expanded resources

pkg/expansion/fixtures/fixtures.go

@@ -191,6 +191,32 @@ metadata:
     app: nginx
   name: nginx-deployment-pod
   namespace: default
+  ownerReferences:
+  - apiVersion: apps/v1
+    kind: Deployment
+    name: nginx-deployment
+spec:
+  containers:
+  - args:
+    - "/bin/sh"
+    image: nginx:1.14.2
+    name: nginx
+    ports:
+    - containerPort: '80'
+`
+
+	PodNoMutateWithNs = `
+apiVersion: v1
+kind: Pod
+metadata:
+  labels:
+    app: nginx
+  name: nginx-deployment-pod
+  namespace: not-default
+  ownerReferences:
+  - apiVersion: apps/v1
+    kind: Deployment
+    name: nginx-deployment
 spec:
   containers:
   - args:
@@ -209,6 +235,10 @@ metadata:
     app: nginx
   name: nginx-deployment-pod
   namespace: default
+  ownerReferences:
+  - apiVersion: apps/v1
+    kind: Deployment
+    name: nginx-deployment
 spec:
   containers:
   - args:
@@ -228,6 +258,10 @@ metadata:
     app: nginx
   name: nginx-deployment-pod
   namespace: not-default
+  ownerReferences:
+  - apiVersion: apps/v1
+    kind: Deployment
+    name: nginx-deployment
 spec:
   containers:
   - args:
@@ -247,6 +281,10 @@ metadata:
     app: nginx
   name: nginx-deployment-pod
   namespace: default
+  ownerReferences:
+  - apiVersion: apps/v1
+    kind: Deployment
+    name: nginx-deployment
 spec:
   containers:
   - args:
@@ -267,6 +305,10 @@ metadata:
     owner: admin
   name: nginx-deployment-pod
   namespace: default
+  ownerReferences:
+  - apiVersion: apps/v1
+    kind: Deployment
+    name: nginx-deployment
 spec:
   containers:
   - args:
@@ -546,6 +588,10 @@ metadata:
     fluffy: extremely
   name: big-chungus-kitten
   namespace: default
+  ownerReferences:
+  - apiVersion: cat.myapp.sh/v1alpha1
+    kind: Cat
+    name: big-chungus
 spec:
   breed: calico
   weight: 10
@@ -560,6 +606,10 @@ metadata:
     shouldPet: manytimes
   name: big-chungus-purr
   namespace: default
+  ownerReferences:
+  - apiVersion: cat.myapp.sh/v1alpha1
+    kind: Cat
+    name: big-chungus
 spec:
   loud: very
 `
@@ -591,6 +641,10 @@ kind: Job
 metadata:
   name: my-cronjob-job
   namespace: default
+  ownerReferences:
+  - apiVersion: batch/v1
+    kind: CronJob
+    name: my-cronjob
 spec:
   template:
     spec:
@@ -612,6 +666,10 @@ metadata:
     owner: admin
   name: my-cronjob-job-pod
   namespace: default
+  ownerReferences:
+  - apiVersion: batch/v1
+    kind: Job
+    name: my-cronjob-job
 spec:
   containers:
   - args:

pkg/expansion/system.go

@@ -246,10 +246,53 @@ func expandResource(obj *unstructured.Unstructured, ns *corev1.Namespace, templa
 	}
 
 	resource.SetName(mockNameForResource(obj, resultantGVK))
+	ensureOwnerReference(resource, obj)
 
 	return resource, nil
 }
 
+// ensureOwnerReference appends an OwnerReference describing parent to the resultant
+// resource if one is not already present.
+func ensureOwnerReference(resultant, parent *unstructured.Unstructured) {
+	if resultant == nil || parent == nil {
+		return
+	}
+
+	parentAPIVersion := parent.GetAPIVersion()
+	parentKind := parent.GetKind()
+	parentName := parent.GetName()
+	if parentAPIVersion == "" || parentKind == "" || parentName == "" {
+		return
+	}
+
+	ownerRef := map[string]interface{}{
+		"apiVersion": parentAPIVersion,
+		"kind":       parentKind,
+		"name":       parentName,
+	}
+
+	refs, found, err := unstructured.NestedSlice(resultant.Object, "metadata", "ownerReferences")
+	if err != nil {
+		return
+	}
+	if found {
+		for _, ref := range refs {
+			refMap, ok := ref.(map[string]interface{})
+			if !ok {
+				continue
+			}
+			if refMap["apiVersion"] == parentAPIVersion && refMap["kind"] == parentKind && refMap["name"] == parentName {
+				return
+			}
+		}
+	} else {
+		refs = []interface{}{}
+	}
+
+	refs = append(refs, ownerRef)
+	_ = unstructured.SetNestedSlice(resultant.Object, refs, "metadata", "ownerReferences")
+}
+
 // mockNameForResource returns a mock name for a resultant resource created
 // from expanding `gen`. The name will be of the form:
 // "<generator name>-<resultant kind>". For example, a deployment named