I do exactly with the kubernetes url.

But the last step I can't get the external ip with the cmd: kubectl get svc nginx.

root@XXX:~# kubectl expose rc nginx --port=80
service "nginx" exposed

root@in28-051:~# kubectl get svc nginx
NAME      CLUSTER_IP   EXTERNAL_IP   PORT(S)   SELECTOR    AGE
nginx     10.0.0.109   <none>        80/TCP    run=nginx   5m