Lineinfile: muti-line, idempotency, regexp

[dulhaver (Gunnar)]

I am playing with lineinfile

target file before

     1  line 1
     2  line 2
     3  line 3
     4  line 4
     5  line 5
     6  byebye

My playboook

---
- name: insert multi-line something
  hosts: "{{ targets | default('postgres') }}"
  tasks:

   - name: Insert multi-line content into a file
     lineinfile:
       path: /home/postgres/somefile_231011
       regexp: '^line 3'
       line: |
         this is my
         multi line
         content
     become: true
     become_user: postgres

target after 1st run

(as expected)

     1  line 1
     2  line 2
     3  this is my
     4  multi line
     5  content
     6  line 4
     7  line 5
     8  byebye

target file after second run

(this should be identical from the above, but adds my 3 lines plus an additional empty line at the bottom)

     1  line 1
     2  line 2
     3  this is my
     4  multi line
     5  content
     6  line 4
     7  line 5
     8  byebye
     9  this is my
    10  multi line
    11  content
    12

what am I missing?

• I though the regexp would make this idempotent (but apparently doesn’t work)
• Do I need additionally insertberfore/insertafter?

[jpmens (Jan-Piet Mens)]

I think this is correct behaviour. The doc states about regexp:

If the regular expression is not matched, the line will be added to the file in keeping with insertbefore or insertafter settings.

Might you want the blockinfile module?

[mophahr (Moritz)]

Blockinfile seems to be what you’re looking for.

[dulhaver (Gunnar)]

@jpmens

I think this is correct behaviour. The doc states about regexp:

If the regular expression is not matched, the line will be added to the file in keeping with insertbefore or insertafter settings.

Might you want the blockinfile module?

maybe, yes. Would you say the blobk I am rying to sneak in lineinfile with …

line: |
  here are
  my lines
  of code

… part of the problem, or is the takeaway that lineinfile is simpy not idempotent really ?

[jpmens (Jan-Piet Mens)]

I think lineinfile is idempotent, but as your first run has removed the line you’re using as anchor in the regex, it has no other alternative than to append to the end of the file (or the beginning) depending on the insert* parameter.

@dulhaver

regexp: '^line 3'

[valkiriaaquatica]

the problem is with the regex,. In the second excution the line that matcht with the regex does not exist because it was replace in the first execution, so linefile does not found any match for that regex and it ends adding it to the end of the file