[k8s] Adjust externaldns test functions

- Use ctl hostname instead of k8s.kube_host due kube_host
is an ip address of keepalived k8s api.
- Discover ctl with specific role 'k8s_controller'
- Fix nit with awk field
- Fix nit with format fields

User-Story:https://mirantis.jira.com/browse/PROD-12826

Change-Id: I52d89b4d3994338a800eed4f6b5555cad6bdedc8
diff --git a/tcp_tests/templates/virtual-mcp11-k8s-contrail/underlay.yaml b/tcp_tests/templates/virtual-mcp11-k8s-contrail/underlay.yaml
index 240b50b..786fea0 100644
--- a/tcp_tests/templates/virtual-mcp11-k8s-contrail/underlay.yaml
+++ b/tcp_tests/templates/virtual-mcp11-k8s-contrail/underlay.yaml
@@ -199,7 +199,7 @@
                     - admin
 
           - name: {{ HOSTNAME_CTL01 }}
-            role: salt_minion
+            role: k8s_controller
             params:
               vcpu: !os_env SLAVE_NODE_CPU, 2
               memory: !os_env SLAVE_NODE_MEMORY, 2048