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

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}

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.