Ansible: Insert line if not exists

Question

I\'m trying insert a line in a property file using ansible. I want to add some property if it does not exist, but not replace it if such property already exists in the file.

Answer 1

Looks like it does not work if you use backrefs.

Following sample does not add a line

- name: add hosts file entry
  lineinfile:
    path: "/etc/hosts"
    regexp: "foohost"
    line:  "10.10.10.10 foohost"
    state: present
    backrefs: yes

After removing backrefs I got my line added to the file

- name: add hosts file entry
  lineinfile:
    path: "/etc/hosts"
    regexp: "foohost"
    line:  "10.10.10.10 foohost"
    state: present