etcdserver/api/rafthttp/util.go
func addRemoteFromRequest(tr Transporter, r *http.Request) {
	if from, err := types.IDFromString(r.Header.Get("X-Server-From")); err == nil {
		if urls := r.Header.Get("X-PeerURLs"); urls != "" {
			tr.AddRemote(from, strings.Split(urls, ","))
		}
	}
}
func addRemoteFromRequest(tr Transporter, r *http.Request) {
	if from, err := types.IDFromString(r.Header.Get("X-Server-From")); err == nil {
		if urls := r.Header.Get("X-PeerURLs"); urls != "" {
			tr.AddRemote(from, strings.Split(urls, ","))
		}
	}
}
// addRemoteFromRequest adds a remote peer according to an http request header