- name: System update
  apt:
    update_cache: yes
    upgrade: dist
- name: Install common packages
  apt:
    name: "{{ common_packages }}"
    state: present
  when:
    - common_packages is defined
    - common_packages is truthy
- name: Install host-specific packages
  apt:
    name: "{{ host_packages }}"
    state: present
  when:
    - host_packages is defined
    - host_packages is truthy