Add the variable docker_swarm_worker_hostname.

defaults/main.yml

@@ -6,6 +6,7 @@ docker_swarm_manager: False
 docker_swarm_manager_availability: 'drain'
 docker_swarm_node: False
 docker_swarm_node_availability: 'active'
+docker_swarm_worker_hostname: '{{ ansible_fqdn }}'
 docker_swarm_allowed_hosts:
   - '0.0.0.0/0'
 

tasks/swarm_node.yml

@@ -35,7 +35,7 @@
 - block:
   - name: Set the swarm nodes availability. Default 'active'
     docker_node:
-      hostname: '{{ ansible_hostname }}'
+      hostname: '{{ docker_swarm_worker_hostname }}'
       availability: '{{ docker_swarm_node_availability }}'
 
   when: docker_swarm_node | bool