Only check whether a line present in a file (ansible)

Question

In ansible, I need to check whether a particular line present in a file or not. Basically, I need to convert the following command to an ansible task. My goal is to only che

Answer 1

Another way is to use the "replace module" then "lineinfile module".

The algo is closed to the one used when you want to change the values of two variables.

• First, use "replace module" to detect if the line you are looking for is here and change it with the something else. (Like same line + something at the end).
• Then if "replace" is true, It means your line is here then replace the new line with a particularity, with the new line looking.
• Else the line you are looking for is not here.

Example:

# Vars
- name: Set parameters
  set_fact:
    newline      : "hello, i love ansible"
    lineSearched : "hello"
    lineModified : "hello you"

# Tasks
- name: Try to replace the line
  replace:
    dest    : /dir/file
    replace : '{{ lineModified }} '
    regexp  : '{{ lineSearched }}$'
    backup  : yes
  register  : checkIfLineIsHere

- name: Line is here, change it
  lineinfile:
    state   : present
    dest    : /dir/file
    line    : '{{ newline }}'
    regexp  : '{{ lineModified }}$'
  when: checkIfLineIsHere.changed

• If the file contains "hello", it will become "hello you" then "hello, i love ansible" at the end.
• If the file content doesn't contain "hello", the file is not modified.

With the same idea, you can do something if the lineSearched is here:

# Vars
- name: Set parameters
  set_fact:
    newline      : "hello, i love ansible"
    lineSearched : "hello"
    lineModified : "hello you"

# Tasks
- name: Try to replace the line
  replace:
    dest    : /dir/file
    replace : '{{ lineModified }} '
    regexp  : '{{ lineSearched }}$'
    backup  : yes
  register  : checkIfLineIsHere

# If the line is here, I want to add something.
- name: If line is here, do something
  lineinfile:
    state   : present
    dest    : /dir/file
    line    : '{{ newline }}'
    regexp  : ''
    insertafter: EOF
  when: checkIfLineIsHere.changed

# But I still want this line in the file, Then restore it
- name: Restore the searched line.
  lineinfile:
    state   : present
    dest    : /dir/file
    line    : '{{ lineSearched }}'
    regexp  : '{{ lineModified }}$'
  when: checkIfLineIsHere.changed

• If the file contains "hello", the line will still contain "hello" and "hello, i love ansible" at the end.
• If the file content doesn't contain "hello", the file is not modified.