- hosts: sandbox
  tasks:
  - name: test
    docker_service:
      project_name: sample
      definition:
        version: "3"
        services:
          mongo:
            restart: unless-stopped
            image: mongo:3.6

ansible-playbook test.yml -i hosts

- hosts: sandbox
  tasks:
  - name: test
    docker_service:
      project_name: sample
      restarted: yes