Ansible lineinfile insertafter injects line at end of file

Question

I'm using lineinfile as follows:

lineinfile dest=./hosts_exp insertafter='\[hosts1\]' line="xxxxxxxxx" state=present

My hosts_exp is as follows:

[local]
localhost

[hosts1]

[hosts2]

[hosts3]

lineinfile inserts the text after [hosts3] instead of inserting it after [hosts1].

Answer 1

use:

lineinfile:
  dest: "./hosts_exp"
  line: "xxxxxxxxx"
  insertafter: '^\[hosts1\]'
  state: present

Answer 2

example:

- name: "blah"
  lineinfile:
    dest: "/test.sh"
    insertafter: 'test text'
    line: "text add"
    state: present

Answer 3

It appears redundant, but you need to specify the regex too:

lineinfile:
  dest: ./hosts_exp
  insertafter: '\[hosts1\]'
  regexp: '\[hosts1\]'
  line: "xxxxxxxxx"
  state=present

Why? The regexp says "look for this line". The insertafter says "inject the line here".

I tested this; here's the commit. There are a few minor changes in my commit from the line above, use as necessary.

Answer 4

Use backrefs: yes

lineinfile:
  backrefs: yes
  dest: ./hosts_exp
  insertafter: '\[hosts1\]'
  regexp: '\[hosts1\]'
  line: "xxxxxxxxx"
  state=present

This flag changes the operation of the module slightly; insertbefore and insertafter will be ignored, and if the regexp doesn't match anywhere in the file, the file will be left unchanged. If the regexp does match, the last matching line will be replaced by the expanded line parameter.