---
- name: Generate the command to join a node as swarm worker
  hosts: localhost
  gather_facts: yes

  tasks:
    - name: Determine Docker swarm status
      shell: >
        docker info | egrep 'Swarm: '
      register: swarm_status
      become: true

    - name: Prepare the command to join a node as worker in this swarm
      command: docker swarm join-token worker -q
      become: true
      when: "' Swarm: active' in swarm_status.stdout_lines"
      register: worker_join_token

    - set_fact:
        run_on_worker: "sudo docker swarm join --token {{ worker_join_token.stdout }} {{ ansible_eth0.ipv4.address }}:2377"
    
    - debug: var=run_on_worker