---
- name: Detect domain name
  set_fact:
    domainname: "{{ ansible_dns.domain|default(False) or ansible_dns.search.0|default(False) or ansible_domain|default(False) or 'invalid'}}"

- name: Add name/IP to hosts file
  lineinfile: >
    dest=/etc/hosts
    regexp='^{{ ansible_default_ipv4.address }}'
    line='{{ ansible_default_ipv4.address }} {{ ansible_hostname }}.{{ domainname }} {{ ansible_hostname }}'
    backup=yes

- name: Clean/remove 127.0.1.1
  lineinfile: >
    dest=/etc/hosts
    regexp='^127.0.1.1'
    state=absent
    backup=yes

- name: Ensure 127.0.0.1 localhost
  lineinfile: >
    dest=/etc/hosts
    regexp='127.0.0.1'
    line='127.0.0.1 localhost localhost.localdomain'
    insertbefore=BOF
    backup=yes