Fix race condition when accesing Graphite listener

CHANGELOG.md

@@ -8,6 +8,7 @@
 - [#2418](https://github.com/influxdb/influxdb/pull/2418): Fix raft node getting stuck in candidate state
 - [#2415](https://github.com/influxdb/influxdb/pull/2415): Raft leader ID now set on election after failover.
 - [#2426](https://github.com/influxdb/influxdb/pull/2426): Fix race condition around listener address in openTSDB server.
+- [#2426](https://github.com/influxdb/influxdb/pull/2426): Fix race condition around listener address in Graphite server.
 
 ### Features
 - [#2410](https://github.com/influxdb/influxdb/pull/2410) Allow configuration of Raft timers

graphite/graphite_tcp.go

@@ -23,6 +23,7 @@ type TCPServer struct {
 	Logger *log.Logger
 
 	host string
+	mu   sync.Mutex
 }
 
 // NewTCPServer returns a new instance of a TCPServer.
@@ -47,7 +48,9 @@ func (t *TCPServer) ListenAndServe(iface string) error {
 		return err
 	}
 	t.listener = &ln
+	t.mu.Lock()
 	t.host = ln.Addr().String()
+	t.mu.Unlock()
 
 	t.Logger.Println("listening on TCP connection", ln.Addr().String())
 	t.wg.Add(1)
@@ -72,6 +75,8 @@ func (t *TCPServer) ListenAndServe(iface string) error {
 }
 
 func (t *TCPServer) Host() string {
+	t.mu.Lock()
+	defer t.mu.Unlock()
 	return t.host
 }