use variable dns_domain instead of cluster_name for kubedns

roles/kubernetes-apps/ansible/templates/kubedns-rc.yml

@@ -53,7 +53,7 @@ spec:
           timeoutSeconds: 5
         args:
         # command = "/kube-dns"
-        - --domain={{ cluster_name }}.
+        - --domain={{ dns_domain }}.
         - --dns-port=10053
         ports:
         - containerPort: 10053
@@ -91,7 +91,7 @@ spec:
             # net memory requested by the pod constant.
             memory: 50Mi
         args:
-        - -cmd=nslookup kubernetes.default.svc.{{ cluster_name }} 127.0.0.1 >/dev/null && nslookup kubernetes.default.svc.{{ cluster_name }} 127.0.0.1:10053 >/dev/null
+        - -cmd=nslookup kubernetes.default.svc.{{ dns_domain }} 127.0.0.1 >/dev/null && nslookup kubernetes.default.svc.{{ dns_domain }} 127.0.0.1:10053 >/dev/null
         - -port=8080
         - -quiet
         ports: