Support to discovery Submariner Globalnet services

[lonelyCZ]

In some scenario, our clusters are uniformly initialized that have overlap clusterIP and serviceIP network segment, so we need to use Globalnet services of Submariner. But these Globalnet services that have EXTERNAL-IP are created by Submariner, like below submariner-etcfrt5unwnek3jrjr4joya6kfly4q6b, so how to auto discovery these services?

[root@member139 ~]# kubectl get services
NAME                                          TYPE        CLUSTER-IP      EXTERNAL-IP     PORT(S)   AGE
kubernetes                                    ClusterIP   10.96.0.1       <none>          443/TCP   20d
serve                                         ClusterIP   10.106.208.67   <none>          80/TCP    5d
submariner-etcfrt5unwnek3jrjr4joya6kfly4q6b   ClusterIP   10.104.94.141   242.1.255.252   80/TCP    5d

[lonelyCZ]

I'm still trying to see if it can be implemented directly~

[lonelyCZ]

The Submariner can auto create serviceimport for each cluster that has been joined and we can use the service by DNS like nginx.nginx-test.svc.clusterset.local:8080.

But I haven't test it with MultiClusterIngress, I continue to test it.