---
  - hosts: all
    serial: 3
    max_fail_percentage: 20%
    roles:
      - { role: mgrote.set_apt_sources, tags: "apt_sources",
          when: "not 'virt' in group_names" }
      - { role: mgrote.update_packages, tags: "updates" }
      - { role: mgrote.install_packages,
          tags: "install" }