Add the external network to the compose file.

tasks/haproxy-docker-service.yml

@@ -31,10 +31,5 @@
         - '{{ haproxy_docker_compose_dir }}/docker-haproxy-stack.yml'
     run_once: True
 
-  - name: Connect haproxy to the external network
-    command: docker service update --network-add {{ haproxy_docker_overlay_network }} haproxy_haproxy --update-delay 30s --update-parallelism 1
-    run_once: True
-    ignore_errors: True
-
   when: docker_swarm_manager_main_node is defined and docker_swarm_manager_main_node | bool
   tags: [ 'haproxy', 'docker_haproxy', 'docker_swarm', 'docker' ]

templates/haproxy-docker-stack.yml.j2

@@ -1,4 +1,8 @@
-version: '3.6'
+version: '3.2'
+
+networks:
+  {{ haproxy_docker_overlay_network }}:
+    external: true
 
 services:
   haproxy:
@@ -7,6 +11,8 @@ services:
       - {{ haproxy_cert_dir }}:{{ haproxy_cert_dir }}:ro
       - /etc/haproxy:/usr/local/etc/haproxy:ro
       - /var/run/docker.sock:/var/run/docker.sock
+    networks:
+      - {{ haproxy_docker_overlay_network }}
     ports:
       - target: {{ haproxy_default_port }}
         published: {{ haproxy_default_port }}