Fix the problem with ansible_host for docker

WIP

This solves the problem with domain name without dropping the ansible_host.
Ansible_host is just resolved to the ip. By using the ping command we can
avoid another dependencies.

Change-Id: Ic1963d3af6a8bdd68089ac8b599731e35475d81f
Issue-ID: OOM-1573
Signed-off-by: Petr Ospalý <p.ospaly@partner.samsung.com>
diff --git a/ansible/roles/docker/tasks/main.yml b/ansible/roles/docker/tasks/main.yml
index 9851d4d..7240a14 100644
--- a/ansible/roles/docker/tasks/main.yml
+++ b/ansible/roles/docker/tasks/main.yml
@@ -16,11 +16,15 @@
     path: /etc/docker
     state: directory
 
+- name: Resolve the ansible_host address to ip
+  shell: LANG=C ping -n -c1 "{{ hostvars[groups.infrastructure[0]].ansible_host }}" | sed -n 1p | cut -d' ' -f3 | tr -d '()'
+  register: infra_ipv4
+
 - name: Setup docker dns settings
   json_add:
     path: /etc/docker/daemon.json
     key: dns
-    value: "{{ hostvars[groups.infrastructure[0]].ansible_default_ipv4.address }}"
+    value: "{{ infra_ipv4.stdout }}"
   notify:
     - Restart Docker