hack: allow deploying the example app in non-default namespace

hack/example-service-monitoring/deploy

@@ -4,8 +4,16 @@ if [ -z "${KUBECONFIG}" ]; then
     KUBECONFIG=~/.kube/config
 fi
 
-kubectl --kubeconfig="$KUBECONFIG" apply -f manifests/examples/example-app/prometheus-frontend-svc.yaml
-kubectl --kubeconfig="$KUBECONFIG" apply -f manifests/examples/example-app/example-app.yaml
-kubectl --kubeconfig="$KUBECONFIG" create -f manifests/examples/example-app/prometheus-frontend.yaml
-kubectl --kubeconfig="$KUBECONFIG" create -f manifests/examples/example-app/servicemonitor-frontend.yaml
+if [ -z "${NAMESPACE}" ]; then
+    NAMESPACE=default
+fi
+
+kubectl --namespace "$NAMESPACE" --kubeconfig="$KUBECONFIG" apply -f manifests/examples/example-app/prometheus-frontend-svc.yaml
+kubectl --namespace "$NAMESPACE" --kubeconfig="$KUBECONFIG" apply -f manifests/examples/example-app/example-app.yaml
+
+# `kubectl apply` is currently not working for third party resources so we are
+# using `kubectl create` here for the time being.
+# (https://github.com/kubernetes/kubernetes/issues/29542)
+kubectl --namespace "$NAMESPACE" --kubeconfig="$KUBECONFIG" create -f manifests/examples/example-app/prometheus-frontend.yaml
+kubectl --namespace "$NAMESPACE" --kubeconfig="$KUBECONFIG" create -f manifests/examples/example-app/servicemonitor-frontend.yaml
 

hack/example-service-monitoring/teardown

@@ -4,5 +4,9 @@ if [ -z "${KUBECONFIG}" ]; then
     KUBECONFIG=~/.kube/config
 fi
 
-kubectl --kubeconfig="$KUBECONFIG" delete -f manifests/examples/example-app
+if [ -z "${NAMESPACE}" ]; then
+    NAMESPACE=default
+fi
+
+kubectl --namespace "$NAMESPACE" --kubeconfig="$KUBECONFIG" delete -f manifests/examples/example-app