The overlay networks can be more than one.

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+        "ansible.python.interpreterPath": "/opt/local/bin/python"
+}

tasks/haproxy-docker-service.yml

@@ -1,38 +1,37 @@
 ---
-- name: Manage the composition of haproxy as a docker swarm service
+- name: haproxy-docker-service | Manage the composition of haproxy as a docker swarm service
+  tags: ['haproxy', 'docker_haproxy', 'docker_swarm', 'docker']
   block:
-  - name: Create the local haproxy configuration directory
+  - name: haproxy-docker-service | Create the local haproxy configuration directory
     ansible.builtin.file: dest=/etc/haproxy state=directory mode='0755'
 
-  - name: Create the local directory for the socket volume
+  - name: haproxy-docker-service | Create the local directory for the socket volume
     ansible.builtin.file: dest={{ haproxy_docker_socket_dir }} state=directory mode='0755'
 
-  - name: Install a bare haproxy configuration if there's none
+  - name: haproxy-docker-service | Install a bare haproxy configuration if there's none
     ansible.builtin.copy: src=haproxy-sample.cfg dest=/etc/haproxy/haproxy.cfg mode='0644' force=no
 
-  tags: [ 'haproxy', 'docker_haproxy', 'docker_swarm', 'docker' ]
-
-- name: Manage the composition of haproxy as a docker swarm service
+- name: haproxy-docker-service | Manage the composition of haproxy as a docker swarm service
+  when: docker_swarm_manager_main_node is defined and docker_swarm_manager_main_node | bool
+  tags: ['haproxy', 'docker_haproxy', 'docker_swarm', 'docker']
   block:
-  - name: Create the destination directory of the haproxy docker compose file
+  - name: haproxy-docker-service | Create the destination directory of the haproxy docker compose file
     ansible.builtin.file: dest={{ haproxy_docker_compose_dir }} state=directory mode='0755'
 
-  - name: Install the docker compose file
+  - name: haproxy-docker-service | Install the docker compose file
     ansible.builtin.template: src=haproxy-docker-stack.yml.j2 dest={{ haproxy_docker_compose_dir }}/docker-haproxy-stack.yml mode='0644'
 
-  - name: Create the overlay network that will be joined by the proxied services
+  - name: haproxy-docker-service | Create the overlay network that will be joined by the proxied services
     community.docker.docker_network:
-      name: '{{ haproxy_docker_overlay_network }}'
+      name: '{{ item }}'
       driver: overlay
       scope: swarm
+    loop: '{{ haproxy_docker_overlay_default_network + haproxy_docker_swarm_overlay_additional_networks }}'
 
-  - name: Run the docker compose file to start the service
+  - name: haproxy-docker-service | Run the docker compose file to start the service
     community.docker.docker_stack:
       name: haproxy
       state: present
       compose:
         - '{{ haproxy_docker_compose_dir }}/docker-haproxy-stack.yml'
-    run_once: True
-
-  when: docker_swarm_manager_main_node is defined and docker_swarm_manager_main_node | bool
-  tags: [ 'haproxy', 'docker_haproxy', 'docker_swarm', 'docker' ]
+    run_once: true

vars/main.yml

@@ -1,2 +1,3 @@
 ---
-haproxy_docker_overlay_network: 'haproxy-public'
+haproxy_docker_overlay_default_network:
+  - 'haproxy-public'