Get OS version for an inventory with ad-hoc ansible

ansible-fact.sh

# The setup command allows filtering facts
# More info: https://docs.ansible.com/ansible/latest/modules/setup_module.html
# inventory_file = path to inventory file (if not normal role layout)
# host_group = group to query. use all for all hosts
ansible -i inventory_file host_group -m setup -a 'filter=ansible_distribution_version'

# For a Ubuntu Bionic Host the distribution facts look like this:
#        "ansible_distribution": "Ubuntu", 
#        "ansible_distribution_file_parsed": true, 
#        "ansible_distribution_file_path": "/etc/os-release", 
#        "ansible_distribution_file_variety": "Debian", 
#        "ansible_distribution_major_version": "18", 
#        "ansible_distribution_release": "bionic", 
#        "ansible_distribution_version": "18.04"