---
- hosts: Docker
  become: true
  become_method: sudo
  become_user: root
  vars:
   GOTIFY_IP: xxx #[Your gotify host IP goes here]
   GOTIFY_PORT: xxx #[Your gotify port goes here]
   GOTIFY_TOKEN: xxx #[Your app token goes here]  
   ansible_python_interpreter: /usr/bin/python3
  
  tasks:

    - name: prune non-dangling images
      community.docker.docker_prune:
        containers: false
        images: true
        images_filters:
          dangling: false
        networks: false
        volumes: false
        builder_cache: false

    - name: Check if reboot is required
      stat:
        path: /var/run/reboot-required
      register: reboot_required_file

    - name: Show Output of required reboots
      debug: msg="{{ reboot_required_file.stat.exists == true }}" 

    - name: Rebooting machine
      shell: sleep 2 && shutdown -r now "Ansible updates triggered"
      async: 1
      poll: 0
      ignore_errors: true
      when: reboot_required_file.stat.exists

    - name: Waiting for the machine to come back
      local_action: wait_for host={{ ansible_host }} state=started port=22 delay=30
      become: false
      when: reboot_required_file.stat.exists

    - name: notify via Gotify
      uri:
        url: 'http://{{ GOTIFY_IP }}:{{ GOTIFY_PORT }}/message?token={{ GOTIFY_TOKEN }}'
        method: POST
        body:
          title:
            content: clean docker hosts
          message: 
            content: The clean docker playbook has completed for {{ ansible_host }} and is now updated. A required reboot is {{ reboot_required_file.stat.exists == true }}.
          priority:
            content: '5'
        body_format: form-multipart
      register: result
...