An ansible playbook and shell script wrapper (for cron) to gather facts, including what virtualization guests might be running on a virtualization host. (And yes, the quotes might be wonky on the debug output at the moment).

gather-facts.sh

#!/bin/bash

export PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/bin:/root/bin
export ANSIBLE_GATHERING=implicit

script -f -c 'time ansible-playbook --key-file /root/.ssh/id_rsa_ansible /etc/ansible/playbooks/gather-facts.yml' /tmp/ansible-gather-facts.log

gather-facts.yml

---
- hosts: all

  pre_tasks:
    - name: Make sure /etc/ansible/facts.d exists
      file:
        path: /etc/ansible/facts.d
        state: directory

    - name: Push facts files
      copy:
        src: /etc/ansible/facts.d/firewalld.fact
        dest: /etc/ansible/facts.d/
      when:
        - (ansible_facts['distribution'] in [ 'CentOS', 'RedHat', 'Rocky' ] and ansible_facts['distribution_major_version']|int >= 7) or
          (ansible_facts['distribution'] in [ 'Fedora' ] and ansible_facts['distribution_major_version']|int >= 28)
        - inventory_hostname != 'myserver'

  tasks:
    - name: Initial Debug
      debug:
         msg: "Host {{inventory_hostname}}'s virtualization role is \\\"{{ansible_facts['virtualization_role']}}\\\""

    - name: Refresh local ansible facts
      setup:
        filter: 'ansible_local'
      register: mycmd

    - name: Debug refreshed vars
      debug:
        var: mycmd
        verbosity: 1

    - name: Get guest virtual machines
      virt:
        command: list_vms
      register: list_vms
      when:
        - ansible_facts['virtualization_role'] == "host"
        - inventory_hostname != 'workstation'
        - inventory_hostname != 'nas'

    - name: Save guest virtual hosts as cachable fact
      set_fact:
        cacheable: yes
        guest_vms: "{{ list_vms.list_vms }}"
      when:
        - ansible_facts['virtualization_role'] == "host"
        - inventory_hostname != 'workstation'
        - inventory_hostname != 'nas'

    - name: Create groups for virtual host type/role.
      group_by:
        key: virt_{{ ansible_virtualization_type }}_{{ ansible_virtualization_role }}
      when:
        "ansible_facts['virtualization_type'] is defined and ansible_facts['virtualization_type'] not in ['', 'NA']"

    - name: Create group based on OS family/version for RHEL/CentOS/Rocky
      group_by:
        key: el{{ ansible_distribution_major_version }}_{{ ansible_architecture }}
        parents:
        - el{{ ansible_distribution_major_version }}
      when:
        ansible_facts['os_family'] == 'RedHat' and ansible_facts['distribution'] != 'Fedora'

    - name: Debug
      vars:
        msg: |
          Module Variables ("vars"):
           --------------------------------
           {{ vars | to_nice_json }}

           Environment Variables ("environment"):
           --------------------------------
           {{ environment | to_nice_json }}

           GROUP NAMES Variables ("group_names"):
           --------------------------------
           {{ group_names | to_nice_json }}

           GROUPS Variables ("groups"):
           --------------------------------
           {{ groups | to_nice_json }}

           HOST Variables ("hostvars"):
           --------------------------------
           {{ hostvars | to_nice_json }}

      debug:
        msg: "{{ msg.split('\n') }}"