main.yml

---
  - hosts: all
    become: yes
    roles:
      - { role: apt_update, when: ( ansible_distribution == "Ubuntu" ) or
                                  ( ansible_distribution == "Debian" ) }
      - { role: yum_update, when: ( ansible_distribution == "CentOS" ) or
                                  ( ansible_distribution == "Amazon" ) or
                                  ( ansible_distribution == "RedHat" ) }
    vars:
      reboot_ok: false

# How to run
# ansible-playbook -b -u <user> --private-key <path to key> -i hosts -l <host-group> main.yml [--extra-vars reboot_ok=true]