library/centos/roles/firewalld/tasks/disable_firewalld.yml

@@ -1,5 +1,5 @@
 ---
 - name: Ensure that the firewalld service is stopped and disabled if we do not want it
   service: name=firewalld state=stopped enabled=no
-  when: not firewalld_enabled
+  when: not firewalld_enabled | bool
   tags: [ 'iptables', 'firewall', 'firewalld' ] 

library/centos/roles/firewalld/tasks/firewalld_rules.yml

@@ -6,7 +6,7 @@
 
   - name: Open the ssh service to the world. We rely on fail2ban to stop unauthorized accesses
     firewalld: service=ssh zone={{ firewalld_default_zone }} permanent=True state=enabled immediate=True
-    when: firewalld_ssh_enabled_on_default_zone
+    when: firewalld_ssh_enabled_on_default_zone | bool
 
   - name: Set the firewalld default zone.
     command: firewall-cmd --set-default-zone={{ firewalld_default_zone }}

library/centos/roles/firewalld/tasks/main.yml

@@ -1,7 +1,7 @@
 ---
 - import_tasks: firewalld_rules.yml
-  when: firewalld_enabled
+  when: firewalld_enabled | bool
 
 - import_tasks: disable_firewalld.yml
-  when: not firewalld_enabled
+  when: not firewalld_enabled | bool