Added missing ClusterUserDefinedNetwork, based on feedback from Robert G.

Author: rbo

content/cluster-installation/hosted-control-plane/tenant-network/cudn-localnet1-2003.yaml

@@ -0,0 +1,22 @@
+apiVersion: k8s.ovn.org/v1
+kind: ClusterUserDefinedNetwork
+metadata:
+  name: cudn-localnet1-2003
+spec:
+  namespaceSelector:
+    matchExpressions:
+      - key: kubernetes.io/metadata.name
+        operator: In
+        values:
+          - default
+  network:
+    localnet:
+      ipam:
+        mode: Disabled
+      physicalNetworkName: localnet1
+      role: Secondary
+      vlan:
+        access:
+          id: 2003
+        mode: Access
+    topology: Localnet

content/cluster-installation/hosted-control-plane/tenant-network/index.md

@@ -237,6 +237,12 @@ spec:
 
 1. Attach NodePool VMs to the tenant segment using a user-defined network (UDN) `localnet` attachment (`default/cudn-localnet1-2003` in this lab).
 
+??? example "ClusterUserDefinedNetwork for `default/cudn-localnet1-2003`"
+
+    ```yaml
+    --8<-- "content/cluster-installation/hosted-control-plane/tenant-network/cudn-localnet1-2003.yaml"
+    ```
+
 ### Deploy external load balancer for the Hosted-Cluster API (`api-lb`)
 
 Use an RHEL 9 virtual machine with HAProxy.
@@ -285,6 +291,14 @@ Add DNS record:
 * WebUI bug: ACM shows `https://console-openshift-console.apps.tenant-a.apps.ocp5.stormshift.coe.muc.redhat.com/` for the console, but the URL should be `https://console-openshift-console.apps.tenant-a.coe.muc.redhat.com/`.
 * Add custom endpoint publishing strategy
 * Find a solution for the NodePort chicken-and-egg problem of the external API load balancer
+* Improve ClusterUserDefinedNetwork with following selector:
+
+    ```yaml
+    namespaceSelector:
+      matchExpressions:
+      - key: hypershift.openshift.io/hosted-control-plane
+        operator: Exists
+    ```
 
 ## Verions