Give this a try for rhel7 hosts.

roles/base/tasks/main.yml

@@ -12,6 +12,10 @@
   - packages
   - base
 
+- name: make sure hostname is set right on rhel7 hosts
+  command: hostnamectl set-hostname {{ ansible_fqdn }}
+  when: ( ansible_fqdn != inventory_hostname ) and ansible_distribution_major_version == '7'
+
 - name: sshd_config 
   copy: src={{ item }} dest=/etc/ssh/sshd_config mode=600
   with_first_found: