create metadata, start cleaning

Change-Id: I9c978590ec408630bf2ec63e5be64bb26bd86080
get_ns(), get_veth_pair()

Change-Id: Id584f96c586f47df583c2befcc09ae014e8dcb7c
remove unnided + stop + monitor + half_of_start

Change-Id: Ibe31147bee3dafd69df9230374a26fd2bacc187a