Example #1
0
// Send join requests to peer.
func (s *PeerServer) joinByPeer(server raft.Server, peer string, scheme string) error {
	var b bytes.Buffer

	// t must be ok
	t, _ := server.Transporter().(*transporter)

	// Our version must match the leaders version
	versionURL := url.URL{Host: peer, Scheme: scheme, Path: "/version"}
	version, err := getVersion(t, versionURL)
	if err != nil {
		return fmt.Errorf("Error during join version check: %v", err)
	}
	if version < store.MinVersion() || version > store.MaxVersion() {
		return fmt.Errorf("Unable to join: cluster version is %d; version compatibility is %d - %d", version, store.MinVersion(), store.MaxVersion())
	}

	json.NewEncoder(&b).Encode(NewJoinCommand(store.MinVersion(), store.MaxVersion(), server.Name(), s.Config.URL, s.server.URL()))

	joinURL := url.URL{Host: peer, Scheme: scheme, Path: "/join"}

	log.Debugf("Send Join Request to %s", joinURL.String())

	resp, req, err := t.Post(joinURL.String(), &b)

	for {
		if err != nil {
			return fmt.Errorf("Unable to join: %v", err)
		}
		if resp != nil {
			defer resp.Body.Close()

			t.CancelWhenTimeout(req)

			if resp.StatusCode == http.StatusOK {
				b, _ := ioutil.ReadAll(resp.Body)
				s.joinIndex, _ = binary.Uvarint(b)
				return nil
			}
			if resp.StatusCode == http.StatusTemporaryRedirect {
				address := resp.Header.Get("Location")
				log.Debugf("Send Join Request to %s", address)
				json.NewEncoder(&b).Encode(NewJoinCommand(store.MinVersion(), store.MaxVersion(), server.Name(), s.Config.URL, s.server.URL()))
				resp, req, err = t.Post(address, &b)

			} else if resp.StatusCode == http.StatusBadRequest {
				log.Debug("Reach max number peers in the cluster")
				decoder := json.NewDecoder(resp.Body)
				err := &etcdErr.Error{}
				decoder.Decode(err)
				return *err
			} else {
				return fmt.Errorf("Unable to join")
			}
		}

	}
}