Add check for designate service


Related-prod: PROD-29567

Change-Id: I495c2d1004fe47239c46ace46a14f1afc959bf7b
diff --git a/_modules/runtest/tempest_sections/dns.py b/_modules/runtest/tempest_sections/dns.py
index 7411df0..998f021 100644
--- a/_modules/runtest/tempest_sections/dns.py
+++ b/_modules/runtest/tempest_sections/dns.py
@@ -47,6 +47,10 @@
 
     @property
     def zone_id(self):
+        ds = conditions.BaseRule(field='designate.server.enabled', op='eq',val=True)
+        if len(self.get_nodes_where_condition_match(ds)) == 0:
+            return
+
         c = conditions.BaseRule(field='keystone.client.enabled', op='eq',
                                 val=True)
         nodes = self.get_nodes_where_condition_match(c)