---
- name: install packages
  package:
    name: firefox
    state: installed

- name: create preferences directory
  file:
    path: /usr/lib64/firefox/defaults/preferences
    state: directory
    mode: 0755
    owner: root
    group: "{{ ansible_wheel }}"

- name: install default settings
  copy:
    dest: /usr/lib64/firefox/defaults/preferences/00-foo.sh.js
    src: foo.sh.js
    mode: 0644
    owner: root
    group: "{{ ansible_wheel }}"