"Undefined variable" error on Ansible when run over Windows machines - windows

Question

This is a very simple Ansible playbook I run from AWX to get information about hosts, and it works as intended on Linux machines:
---
- name: Get some info
debug:
msg: "{{ ansible_hostname }} {{ ansible_default_ipv4.address }} {{ ansible_distribution }}"
However, when run over Windows machines, it returns this error:
fatal: [MYWINHOST1]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'ansible_default_ipv4' is undefined\n\nThe error appears to be in '/tmp/bwrap_21138_4q41r57e/awx_21138_is8pox6p/project/roles/windows/tasks/getsomeinfo.yml': line 3, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: Get some info\n ^ here\n"}
How do I access and print the same Ansible facts values from a Windows machine?

Answer 1

From the documentation:
ansible_facts
This key should contain a dictionary which will be appended to the facts assigned to the host. These will be directly accessible and don’t require using a registered variable.
Source: https://docs.ansible.com/ansible/latest/reference_appendices/common_return_values.html#ansible-facts
So, if printing hostvars[inventory_hostname] shows you a variable ansible_facts.ip_addresses then you can access it via ansible_ip_addresses — if that node only have one IP address assigned, see below if this is not the case:
- debug:
msg: >-
{{ ansible_hostname }}
{{ ansible_ip_addresses }}
{{ ansible_distribution }}
Mind that there is a bug that has been reported to the Ansible tracker about Windows machine having multiple IP addresses, and that it does not seems to be as trivial of a consensus as though what really is the default IP address:
There's really not a great solution to this issue- the concept of a "default IP address" means different things to different people, and the Linux fact is wrong as much as it's right. Usually this comes down to locating an address on a particular subnet, which we have to filters to assist with given the list of IP addresses... Given the lack of clarity on this, I'm going to close this issue.
Source: nitzmahone's comment on the issue https://github.com/ansible/ansible/issues/17014
So, to clear things up, the fact gathering in Windows and Linux are not implementing the same variable, you sure can work around this, implementing an inline-if:
- debug:
msg: >-
{{ ansible_hostname }}
{{
ansible_ip_addresses
if ansible_os_family == "Windows"
else ansible_default_ipv4.address
}}
{#
Mind that you still have to implement your own logic
of what is the "default" IP if you have more
than one IP address on that Windows machine, as linked above
#}
{{ ansible_distribution }}

Answer 2

The first thing I would do is using the new notation (removing any possibility to have failures due to misinterpretation):
---
- name: Gather Info
hosts: all
gather_facts: yes
tasks:
- name: Get some info
debug:
msg: "{{ ansible_hostname }} {{ ansible_default_ipv4['address'] }} {{ ansible_distribution }}"
Unless you're using caching mechanisms like redis/memcache, sometimes it takes some time to get results and probably is more efficient to get minimum facts.
To address the issue, I can't assist too much but if there's a bug closed in the windows module only developers could help here, as either Ansible team address this somehow or you might need to develop a small module for your needs.
UPDATE #1:
For what I can see if you gather a subset, you miss some information that you require ...
If you activate the gather_facts it doesn't fail with The error was: 'ansible_default_ipv4' is undefined.
UPDATE #2:
In regards to your error message, looks like something copied didn't was properly aligned.
In regards to how to get access to the variables:
pre_tasks:
- name: Collect only minimum facts.
ansible.builtin.setup:
gather_subset: "!all"
register: facts
When I register the collection, I use: facts.ansible_facts.ansible_domain to get the domain. maybe that give you enough insight about how to get the variables you need.