---
- name: Define certbot_package (Ubuntu 16.04).
  set_fact:
    certbot_package: letsencrypt
  when: ansible_distribution == 'Ubuntu' and ansible_distribution_version == '16.04'

- name: Define certbot_package.
  set_fact:
    certbot_package: certbot
  when: certbot_package is undefined

- name: Install Certbot.
  package: "name={{ certbot_package }} state=present"

- name: Set Certbot script variable.
  set_fact:
    certbot_script: "{{ certbot_package }}"