External control plane part 2 test (#10127)

* update for https://github.com/istio/istio.io/issues/10068

* update based on review

* update cleanup

* more cleanup and update doc

content/en/docs/setup/install/external-controlplane/index.md

@@ -496,8 +496,6 @@ including gateways, if needed.
 
 ## Adding clusters to the mesh (optional) {#adding-clusters}
 
-{{< boilerplate experimental >}}
-
 This section shows you how to expand an existing external control plane mesh to multicluster by adding another remote cluster.
 This allows you to easily distribute services and use [location-aware routing and fail over](/docs/tasks/traffic-management/locality-load-balancing/) to support high availability of your application.
 

content/en/docs/setup/install/external-controlplane/test.sh

@@ -115,22 +115,62 @@ export GATEWAY_URL=$(kubectl \
 
 _verify_contains snip_enable_gateways_6 "Hello version: v1"
 
+# Adding clusters to the mesh.
+
+export CTX_SECOND_CLUSTER="${KUBE_CONTEXTS[1]}"
+export SECOND_CLUSTER_NAME="${CTX_SECOND_CLUSTER}"
+
+snip_get_second_config_cluster_iop
+echo y | snip_register_the_new_cluster_2
+
+# Confirm remote cluster’s webhook configuration has been installed
+_verify_like snip_register_the_new_cluster_3 "$snip_register_the_new_cluster_3_out"
+
+# Create a secret with credentials to allow the control plane to access the endpoints on the second remote cluster and install it
+snip_register_the_new_cluster_4
+
+# Setup east-west gateways
+snip_setup_eastwest_gateways_1
+snip_setup_eastwest_gateways_2
+
+_verify_like snip_setup_eastwest_gateways_3 "$snip_setup_eastwest_gateways_3_out"
+_verify_like snip_setup_eastwest_gateways_4 "$snip_setup_eastwest_gateways_4_out"
+
+snip_setup_eastwest_gateways_5
+snip_setup_eastwest_gateways_6
+
+# Validate the installation.
+snip_validate_the_installation_1
+snip_validate_the_installation_2
+_verify_like snip_validate_the_installation_3 "$snip_validate_the_installation_3_out"
+_verify_contains snip_validate_the_installation_4 "Hello version:"
+_verify_lines snip_validate_the_installation_5 "
++ Hello version: v1
++ Hello version: v2
+"
+
 # @cleanup
 _set_kube_vars # helper function to initialize KUBECONFIG_FILES and KUBE_CONTEXTS
 export CTX_EXTERNAL_CLUSTER="${KUBE_CONTEXTS[0]}"
 export CTX_REMOTE_CLUSTER="${KUBE_CONTEXTS[2]}"
+export CTX_SECOND_CLUSTER="${KUBE_CONTEXTS[1]}"
 
 # TODO put the cleanup instructions in the doc and then call the snips.
 kubectl delete ns sample --context="${CTX_REMOTE_CLUSTER}"
+kubectl delete ns sample --context="${CTX_SECOND_CLUSTER}"
 
 kubectl delete -f external-istiod-gw.yaml --context="${CTX_EXTERNAL_CLUSTER}"
 
 istioctl manifest generate -f remote-config-cluster.yaml | kubectl delete --context="${CTX_REMOTE_CLUSTER}" -f -
+istioctl manifest generate -f second-config-cluster.yaml | kubectl delete --context="${CTX_SECOND_CLUSTER}" -f -
 istioctl manifest generate -f external-istiod.yaml | kubectl delete --context="${CTX_EXTERNAL_CLUSTER}" -f -
 istioctl manifest generate -f controlplane-gateway.yaml | kubectl delete --context="${CTX_EXTERNAL_CLUSTER}" -f -
+istioctl manifest generate -f eastwest-gateway-1.yaml | kubectl delete --context="${CTX_REMOTE_CLUSTER}" -f - 
+istioctl manifest generate -f eastwest-gateway-2.yaml | kubectl delete --context="${CTX_SECOND_CLUSTER}" -f - 
 
 kubectl delete ns istio-system external-istiod --context="${CTX_EXTERNAL_CLUSTER}"
 kubectl delete ns external-istiod --context="${CTX_REMOTE_CLUSTER}"
+kubectl delete ns external-istiod --context="${CTX_SECOND_CLUSTER}"
 kubectl delete ns istio-system --context="${CTX_REMOTE_CLUSTER}" # TODO: remove when https://github.com/istio/istio/issues/31495 fixed
 
-rm external-istiod-gw.yaml remote-config-cluster.yaml external-istiod.yaml controlplane-gateway.yaml
+rm external-istiod-gw.yaml remote-config-cluster.yaml external-istiod.yaml controlplane-gateway.yaml eastwest-gateway-1.yaml eastwest-gateway-2.yaml second-config-cluster.yaml