Find line in file

Archives Ansible Project
1

One of the most recommended things is to use “lineinfiles” with some special attributes for just finding a line in a file.

I have a weird issue with this. If I just lookup one line, like so:

  • name: TEST - Check /tmp/out.log
    lineinfile:
    path: /tmp/out.log
    regexp: “^bla”
    state: absent
    check_mode: yes
    changed_when: false
    register: checklog
    failed_when: not checklog.found

This sequence fails (as expected), because the “bla” line is not in the file. If I enter a string, which is in the file, it doesn’t fail. So far so good.

Now I wanted to examine several lines, but this never fails. “line1” to “line4” are in, “bla” not.
But the result is OK…

  • name: TEST - Check /tmp/out.log
    lineinfile:
    path: /tmp/out.log
    regexp: “{{ item }}”
    state: absent
    check_mode: yes
    changed_when: false
    register: checklog
    with_items:
  • {item: “^line1”}
  • {item: “^line2”}
  • {item: “^line3”}
  • {item: “^line4”}
  • {item: “^bla”}
    failed_when: not checklog.found

Does that make sense at all?

2

Oops. Disregard please:

regexp: “{{ item.item }}”

3

If it never fails is just because you are iterating over items and registering the result of each iteration. So the condition is only evaluated only on the last iteration.

4

No, the reason was the wrong “{{ item.item }}” reference.

Real world example:

  • name: TEST - Check /tmp/out.log for some lines expected to be there
    tags: test
    lineinfile:
    path: /tmp/out.log
    regexp: “{{ item.item }}”
    state: absent
    check_mode: yes
    changed_when: false
    register: checklog
    with_items:
  • { item: “^v=1”}
  • { item: “^s=Kurento Media Server” }
  • { item: “^IceCandidateFound” }
  • { item: “^IceGatheringDone” }
    failed_when: not checklog.found

The failing line is “v=1”, because it is “v=0”. The rest of the lines except the last is there. Result:

TASK [TEST - Check /tmp/out.log for some lines expected to be there] ******************************************************************************************************************************************************************
failed: [ubuntuVM] (item={‘item’: ‘^v=1’}) => {“ansible_loop_var”: “item”, “backup”: “”, “changed”: false, “failed_when_result”: true, “found”: 0, “item”: {“item”: “^v=1”}, “msg”: “”}
ok: [ubuntuVM] => (item={‘item’: ‘^s=Kurento Media Server’}) => {“ansible_loop_var”: “item”, “backup”: “”, “changed”: false, “failed_when_result”: false, “found”: 1, “item”: {“item”: “^s=Kurento Media Server”}, “msg”: “1 line(s) removed”}
ok: [ubuntuVM] => (item={‘item’: ‘^IceCandidateFound’}) => {“ansible_loop_var”: “item”, “backup”: “”, “changed”: false, “failed_when_result”: false, “found”: 12, “item”: {“item”: “^IceCandidateFound”}, “msg”: “12 line(s) removed”}
failed: [ubuntuVM] (item={‘item’: ‘^IceGatheringDone’}) => {“ansible_loop_var”: “item”, “backup”: “”, “changed”: false, “failed_when_result”: true, “found”: 0, “item”: {“item”: “^IceGatheringDone”}, “msg”: “”}

PLAY RECAP ****************************************************************************************************************************************************************************************************************************
ubuntuVM : ok=1 changed=0 unreachable=0 failed=1 skipped=0 rescued=0 ignored=0

So it works as expected

Solved.