discover

type Membership interface {
	Join(Ip []string) (num int, err error)
	Leave()
	Listen(ctx context.Context, outch chan P2PEvent)
	Lookup(id []byte) (addr string)
	NumOfPeers() int
	IsAlive() bool
	MembersIP() (addr []net.IP)
	MembersID() (list [][]byte)
}

type P2PEvent struct {
	EventType string
	NodeID    string
	Addr      net.IP
}