def __virtual__():
    if __grains__['os'] in ('Debian', 'Raspbian', 'Devuan') and not salt.utils.systemd.booted(__context__):
        return __virtualname__
    else:
        return (False, 'The debian_service module could not be loaded: '
                'unsupported OS family and/or systemd running.')
Only work on Debian and when systemd isn't running
dataset/ETHPy150Open saltstack/salt/salt/modules/debian_service.py/__virtual__