package consul import ( "github.com/hashicorp/raft" "github.com/hashicorp/serf/serf" "net" "time" ) // lanEventHandler is used to handle events from the lan Serf cluster func (s *Server) lanEventHandler() { for { select { case e := <-s.eventChLAN: switch e.EventType() { case serf.EventMemberJoin: s.localJoin(e.(serf.MemberEvent)) case serf.EventMemberLeave: case serf.EventMemberFailed: case serf.EventUser: default: s.logger.Printf("[WARN] Unhandled LAN Serf Event: %#v", e) } case <-s.shutdownCh: return } } } // wanEventHandler is used to handle events from the wan Serf cluster func (s *Server) wanEventHandler() { for { select { case e := <-s.eventChWAN: switch e.EventType() { case serf.EventMemberJoin: s.remoteJoin(e.(serf.MemberEvent)) case serf.EventMemberLeave: fallthrough case serf.EventMemberFailed: s.remoteFailed(e.(serf.MemberEvent)) case serf.EventUser: default: s.logger.Printf("[WARN] Unhandled LAN Serf Event: %#v", e) } case <-s.shutdownCh: return } } } // localJoin is used to handle join events on the lan serf cluster func (s *Server) localJoin(me serf.MemberEvent) { // Check for consul members for _, m := range me.Members { ok, dc, port := isConsulServer(m) if !ok { continue } if dc != s.config.Datacenter { s.logger.Printf("[WARN] Consul server %s for datacenter %s has joined wrong cluster", m.Name, dc) continue } go s.joinConsulServer(m, port) } } // remoteJoin is used to handle join events on the wan serf cluster func (s *Server) remoteJoin(me serf.MemberEvent) { for _, m := range me.Members { ok, dc, port := isConsulServer(m) if !ok { s.logger.Printf("[WARN] Non-Consul server in WAN pool: %s %s", m.Name) continue } var addr net.Addr = &net.TCPAddr{IP: m.Addr, Port: port} s.logger.Printf("[INFO] Adding Consul server (Datacenter: %s) (Addr: %s)", dc, addr) // Check if this server is known found := false s.remoteLock.Lock() existing := s.remoteConsuls[dc] for _, e := range existing { if e.String() == addr.String() { found = true break } } // Add ot the list if not known if !found { s.remoteConsuls[dc] = append(existing, addr) } s.remoteLock.Unlock() } } // remoteFailed is used to handle fail events on the wan serf cluster func (s *Server) remoteFailed(me serf.MemberEvent) { for _, m := range me.Members { ok, dc, port := isConsulServer(m) if !ok { continue } var addr net.Addr = &net.TCPAddr{IP: m.Addr, Port: port} s.logger.Printf("[INFO] Removing Consul server (Datacenter: %s) (Addr: %s)", dc, addr) // Remove the server if known s.remoteLock.Lock() existing := s.remoteConsuls[dc] n := len(existing) for i := 0; i < n; i++ { if existing[i].String() == addr.String() { existing[i], existing[n-1] = existing[n-1], nil existing = existing[:n-1] n-- break } } // Trim the list if all known consuls are dead if n == 0 { delete(s.remoteConsuls, dc) } else { s.remoteConsuls[dc] = existing } s.remoteLock.Unlock() } } // joinConsulServer is used to try to join another consul server func (s *Server) joinConsulServer(m serf.Member, port int) { if m.Name == s.config.NodeName { return } var addr net.Addr = &net.TCPAddr{IP: m.Addr, Port: port} var future raft.Future CHECK: // Get the Raft peers peers, err := s.raftPeers.Peers() if err != nil { s.logger.Printf("[ERR] Failed to get raft peers: %v", err) goto WAIT } // Bail if this node is already a peer for _, p := range peers { if p.String() == addr.String() { return } } // Bail if the node is not alive if memberStatus(s.serfLAN.Members(), m.Name) != serf.StatusAlive { return } // Attempt to add as a peer future = s.raft.AddPeer(addr) if err := future.Error(); err != nil { s.logger.Printf("[ERR] Failed to add raft peer: %v", err) } else { return } WAIT: time.Sleep(500 * time.Millisecond) select { case <-s.shutdownCh: return default: goto CHECK } } // memberStatus scans a list of members for a matching one, // returning the status or StatusNone func memberStatus(members []serf.Member, name string) serf.MemberStatus { for _, m := range members { if m.Name == name { return m.Status } } return serf.StatusNone }