def _get_boot_device(ssh_obj, driver_info):
    cmd_to_exec = driver_info['cmd_set'].get('get_boot_device')
    if cmd_to_exec:
        boot_device_map = _get_boot_device_map(driver_info['virt_type'])
        node_name = _get_hosts_name_for_node(ssh_obj, driver_info)
        base_cmd = driver_info['cmd_set']['base_cmd']
        cmd_to_exec = cmd_to_exec.replace('{_NodeName_}', node_name)
        cmd_to_exec = cmd_to_exec.replace('{_BaseCmd_}', base_cmd)
        stdout, stderr = _ssh_execute(ssh_obj, cmd_to_exec)
        return next((dev for dev, hdev in boot_device_map.items()
                     if hdev == stdout), None)
    else:
        raise NotImplementedError()
Get the current boot device.
dataset/ETHPy150Open openstack/ironic/ironic/drivers/modules/ssh.py/_get_boot_device