---
- import_playbook: playbook_ssh_known_host.yml
- name: Configure NTP server
  hosts:
    - all
  gather_facts: yes
  vars_files:
    - vars/ntp.yml
  pre_tasks:
    - apt:
        name: '*'
        update_cache: true
        only_upgrade: true
        state: latest
      when: ansible_facts.os_family == "Debian"
      become: true
      become_method: sudo
    - yum:
        name: '*'
        update_cache: true
        security: true
        state: latest
        update_only: true
      when: ansible_facts.os_family == "RedHat"
      become: true
      become_method: sudo
  roles:
    - {role: ntp_server, tags: ["ntp"], become: true, become_method: sudo}
    - {role: iptables, become: true, become_method: sudo}
...