Extend boolean values section in playbooks_variables

[skilyazhnev]

Hello!

in continuation of this issue

#1279

[ansible-documentation-bot]

Thanks for your Ansible docs contribution! We talk about Ansible documentation on matrix at #docs:ansible.im and on libera IRC at #ansible-docs if you ever want to join us and chat about the docs! We meet there on Tuesdays (see the Ansible calendar) and welcome additions to our weekly agenda items - scroll down to find the upcoming agenda and add a comment to put something new on that agenda.

[oraNod]

LGTM. Thanks @skilyazhnev

[oraNod]

Some minor nits but the rest LGTM

[oraNod]

@ssbarnea and @bcoca Please take a minute to review the latest round of edits. The details seem good to me and I'd like to get them merged.

Thanks again for the docs contribution @skilyazhnev

[bcoca]

This is not really 'ansible native' but YAML that uses true and false and the rest of the list below, it would be 'more true' that True and False are the 'native' options as Ansible evaluation happens inside Python and those are the 'Python native booleans', this also depends on context as inside a {{ }} expression it is Jinja doing the evaluation, which is again using Python under the hood.

[bcoca]

the bool filter, while is it Jinja, it is an Ansible customization which approximates (but does not really match) the YAML booleans, the table below is incorrect as this is the actual code:

    if a is None or isinstance(a, bool):
        return a
    if isinstance(a, string_types):
        a = a.lower()
    if a in ('yes', 'on', '1', 'true', 1):
        return True
    return False

so it realy only converts 'matching True' and everything else is False

[bcoca]

though this is something I'm planning to fix so they are closer to YAML by default but can be 'pythonic' otherwise.