Ansible does not wait for virtual IP to appear

VIP takes time (10-30 seconds) to appear on one of network nodes.
Ansible does not wait for the VIP and starts keystone. The latter
fails because it cannot connect to database thru the VIP.

Change-Id: Ie951ee22565bdbe8ccb68522648758a7174ba156
Closes-Bug: #1494253

ansible/roles/haproxy/tasks/start.yml

@@ -46,3 +46,6 @@
   command: docker exec haproxy /opt/kolla/ensure_latest_config.sh
   register: status
   changed_when: status.stdout.find('changed') != -1
+
+- name: Waiting for virtual IP to appear
+  wait_for: host="{{ kolla_internal_address }}" port="{{ mariadb_port }}"