Owner reference example (argoproj#839)

* Example using resource that will be GC'd.

* Document owner reference option.

examples/README.md

@@ -1043,6 +1043,8 @@ spec:
  backoffLimit: 4
 ```
 
+Resources created in this way are independent of the workflow. If you want the resource to be deleted when the workflow is deleted then you can use [Kubernetes garbage collection](https://kubernetes.io/docs/concepts/workloads/controllers/garbage-collection/) with the workflow resource as an owner reference ([example](./k8s-owner-reference.yaml)).
+
 ## Docker-in-Docker (aka. DinD) Using Sidecars
 An application of sidecars is to implement DinD (Docker-in-Docker).
 DinD is useful when you want to run Docker commands from inside a container. For example, you may want to build and push a container image from inside your build container. In the following example, we use the docker:dind container to run a Docker daemon in a sidecar and give the main container access to the daemon.

examples/k8s-owner-reference.yaml

@@ -0,0 +1,30 @@
+# This example creates a Kubernetes resource that will be deleted
+# when the workflow is deleted via Kubernetes GC.
+#
+# A configmap is used for this example, but the same approach would apply
+# to other more interesting resource types.
+#
+# https://kubernetes.io/docs/concepts/workloads/controllers/garbage-collection/
+apiVersion: argoproj.io/v1alpha1
+kind: Workflow
+metadata:
+ generateName: k8s-owner-reference-
+spec:
+ entrypoint: k8s-owner-reference
+ templates:
+ - name: k8s-owner-reference
+ resource:
+ action: create
+ manifest: |
+ apiVersion: v1
+ kind: ConfigMap
+ metadata:
+ generateName: owned-eg-
+ ownerReferences:
+ - apiVersion: argoproj.io/v1alpha1
+ blockOwnerDeletion: true
+ kind: Workflow
+ name: "{{workflow.name}}"
+ uid: "{{workflow.uid}}"
+ data:
+ some: value