Set the hostname as defined in the inventory.

library/centos/roles/basic-setup/tasks/main.yml

@@ -51,11 +51,16 @@
   command: timedatectl set-timezone {{ timezone }}
   tags: [ 'centos', 'bootstrap' ]
 
-- name: Set the hostname
+- name: Set the hostname when explicitly defined
   hostname: name={{ hostname }}
   when: hostname is defined
   tags: [ 'centos', 'bootstrap' ]
 
+- name: Set the hostname as defined in the inventory
+  hostname: name={{ inventory_hostname }}
+  when: hostname is not defined
+  tags: [ 'bootstrap', 'set_hostname' ]
+
 - name: Configure the main interface to set the correct resolvers. dns1
   lineinfile: name=/etc/sysconfig/network-scripts/ifcfg-eth0 regexp="^DNS1=" line="DNS1={{ dns1 }}"
   when: centos_set_dns_servers