def find_vm_interface(ports=[],
                      vnic_type='normal'):
    """find vm interface

    The function receive port list and search for requested
    vnic_type.

    :param ports: ports connected to specific server
    :param vnic_type: vnic_type nomal/direct/direct_physical

    return port_id, ip_address
    """
    assert len(ports), 'ports is empty or None'
    return [[port['id'], port['fixed_ips'][0]['ip_address']]
            for port in ports['ports']
            if port['binding:vnic_type'] == vnic_type][0]