Explicitly set a hostname by default.

defaults/main.yml

@@ -18,6 +18,7 @@ grub_cmdline_additional_parameters: ""
 sysctl_custom_file: /etc/sysctl.d/90-custom-values.conf
 sysctl_opts_reload: yes
 sysctl_custom_file_state: present
+explicitly_set_hostname: true
 custom_etc_hosts_entries: ""
 custom_etc_hosts_entries_adjunct: ""
 

tasks/hostname.yml

@@ -1,6 +1,6 @@
 ---
 - name: hostname | Add entries to /etc/hosts
-  when: custom_etc_hosts_entries | length > 0
+  when: explicitly_set_hostname
   tags: [ 'systemsetup', 'hostname' ]
   block:
     - name: hostname | Set the hostname when different from the inventory one.