[enterprise-4.17] : Add step to change Argo CD default deletion behaviour

modules/ztp-preparing-the-hub-cluster-for-ztp.adoc

@@ -41,3 +41,38 @@ You can configure the hub cluster with a set of ArgoCD applications that generat
 
 [start=2]
 include::snippets/ztp-patch-argocd-hub-cluster.adoc[]
+
+
+. Optional: If you have existing ArgoCD applications, verify that the `PrunePropagationPolicy=background` policy is set in the `Application` resource by running the following command:
++
+--
+[source,terminal]
+----
+$ oc -n openshift-gitops get applications.argoproj.io  \
+clusters -o jsonpath='{.spec.syncPolicy.syncOptions}' |jq
+----
+
+.Example output for an existing policy
+[source,terminal]
+----
+[
+  "CreateNamespace=true",
+  "PrunePropagationPolicy=background",
+  "RespectIgnoreDifferences=true"
+]
+----
+--
+
+.. If the `spec.syncPolicy.syncOption` field does not contain a `PrunePropagationPolicy` parameter or `PrunePropagationPolicy` is set to the `foreground` value, set the policy to `background` in the `Application` resource. See the following example:
++
+[source,yaml]
+----
+kind: Application
+spec:
+  syncPolicy:
+    syncOptions:
+    - PrunePropagationPolicy=background
+----
+
++
+Setting the `background` deletion policy ensures that the `ManagedCluster` CR and all its associated resources are deleted.