Ansible regex_search fails when I try to use a group with error 'NoneType' object has not attribute 'group'

Question

I have a number of user public keys, obtained via rest call made with the URI module, and I want to pull out the uid contained within that key. Here is the relevant line of my role

- name: find users UID within key
  debug: 
    msg: uid is "{{ item.content | regex_search( 'unixid=(d+)', '\1') }}"

this fails with the error:

'NoneType' object has no attribute 'group'

If I use -vvv on ansible I find that it’s failing on this line

file "/usr/lib/python3.6/site-package/ansible/plugins/filter/core.py", line 156, in regex_search
  match = int(re.match(r'\(d+)', arg).group(1))

By comparison if I do the same regex without the group search the command works fine, other then returning more then the id I want.

I was able to get the desired functionality by chaining two regex_search commands together, but it’s ugly. I’d rather know why groups aren’t working for regex_search.

Asked By: dsollen

||

Source

Answer 1

regex_search is meant to return you the matches of the regex, not the groups, or at least in the current version of Ansible ^{(although there are signs that it should work on the latest version?)}.

You can work around this using regex_findall instead, but you’ll have to add a first filter to deal with the list created:

Given the task:

- debug: 
    msg: >-
      uid is {{ 
        item.content | regex_findall('unixid=(d+)', '\1') | first 
      }}
  vars:
    item:
      content: 000 foo unixid=123 bar 987

This yields the recap:

ok: [localhost] => 
  msg: uid is "123"

Answered By: β.εηοιτ.βε

Answer 2

I ran into a similar problem when following ansible’s regex examples. The problem seems related to escaping backslashes. I found two ways to solve this issue using the latest version of ansible:

The first one requires only the removal of one in your code:

- hosts: localhost
  gather_facts: no

  tasks:
    - vars:
        item:
          content: some text unixid=123 more text
      debug:
        msg: uid is "{{ item.content | regex_search('unixid=(d+)', '1') | first}}"

The second approach leads to a few more changes:

- hosts: localhost
  gather_facts: no

  tasks:
    - vars:
        item:
          content: some text unixid=123 more text
      debug:
        msg: "uid is "{{ item.content | regex_search('unixid=(\d+)', '\1') | first}}""

Both result in the same (desired) output:

PLAY [localhost] *************************************************************************************************

TASK [debug] *****************************************************************************************************
ok: [localhost] => {
    "msg": "uid is "123""
}

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

Answered By: a-ts

Ansible regex_search fails when I try to use a group with error 'NoneType' object has not attribute 'group'

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