Write localhost line in /etc/hosts when testing

In the test builds, localhost is in the inventory and the /etc/hosts
line isn't adjusted properly since the hostname won't split on a
period.

This patch allows the localhost line in /etc/hosts to be
managed properly during testing builds. This affects CentOS
builds intermittently.

Change-Id: I6368b6584265084af6ff98caba68fc067b1f1f22

tasks/rabbitmq_pre_install.yml

@@ -44,7 +44,10 @@
   lineinfile:
     dest: /etc/hosts
     state: present
-    line: "{{ hostvars[item]['ansible_ssh_host'] }} {{ hostvars[item]['ansible_hostname'] }} {{ hostvars[item]['ansible_hostname'].split('.')[0] }}"
+    line: >
+      {{ hostvars[item]['ansible_ssh_host'] }}
+      {{ hostvars[item]['ansible_hostname'] }}
+      {% if hostvars[item]['ansible_hostname'] != 'localhost' %}{{ hostvars[item]['ansible_hostname'].split('.')[0] }}{% endif %}
   with_items: "{{ groups[rabbitmq_host_group] }}"
   tags:
     - rabbitmq-config