---
- hosts: all
  become: yes
  vars:
    umbrella: localhost
  pre_tasks:
    - lineinfile: dest=/etc/hosts line="127.0.0.1 fruitbar.{{ umbrella }}"
      when: ansible_virtualization_type == "virtualbox"
    - apt: update_cache=yes cache_valid_time=3600
  roles:
    - role: fruitbar
...