---
- name: Install dependencies
  apt:
    pkg:
      - apt-transport-https
      - ca-certificates
    state: present

- name: Add VirtualBox to sources.list
  apt_repository:
    repo: deb https://download.virtualbox.org/virtualbox/debian {{ ansible_distribution_release }} contrib
    state: present

- name: Add apt signing key for VirtualBox for Debian >= 8 and Ubuntu >= 16
  apt_key:
    url: https://www.virtualbox.org/download/oracle_vbox_2016.asc
    state: present
  when: (ansible_distribution == "Debian" and ansible_distribution_major_version >= "8") or (ansible_distribution == "Ubuntu" and ansible_distribution_major_version >= "16")

- name: Add apt signing key for VirtualBox for Debian < 8 and Ubuntu < 16
  apt_key:
    url: https://www.virtualbox.org/download/oracle_vbox.asc
    state: present
  when: (ansible_distribution == "Debian" and ansible_distribution_major_version < "8") or (ansible_distribution == "Ubuntu" and ansible_distribution_major_version < "16")

- name: Install VirtualBox
  apt:
    pkg:
      - virtualbox-{{ virtualbox_version }}
    update_cache: yes
    state: present
...