// 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")
}
}
}
}
// Checks whether a given version is supported.
func (ps *PeerServer) VersionCheckHttpHandler(w http.ResponseWriter, req *http.Request) {
log.Debugf("[recv] Get %s%s ", ps.Config.URL, req.URL.Path)
vars := mux.Vars(req)
version, _ := strconv.Atoi(vars["version"])
if version >= store.MinVersion() && version <= store.MaxVersion() {
w.WriteHeader(http.StatusOK)
} else {
w.WriteHeader(http.StatusForbidden)
}
}
func (s *PeerServer) startAsLeader() {
// leader need to join self as a peer
for {
_, err := s.raftServer.Do(NewJoinCommand(store.MinVersion(), store.MaxVersion(), s.raftServer.Name(), s.Config.URL, s.server.URL()))
if err == nil {
break
}
}
log.Debugf("%s start as a leader", s.Config.Name)
}