From 1347df814de0d603ef844d53b2c8d54fc760b75e Mon Sep 17 00:00:00 2001
From: pingcap-github-bot <sre-bot@pingcap.com>
Date: Fri, 10 Apr 2020 18:16:06 +0800
Subject: [PATCH] server: if status address already in use, return an error
 (#15177) (#16291)

---
 server/http_status.go | 57 +++++++++++++++++++++++--------------------
 server/server.go      |  5 ++++
 server/tidb_test.go   | 13 ++++++++++
 3 files changed, 49 insertions(+), 26 deletions(-)

diff --git a/server/http_status.go b/server/http_status.go
index 32f81a15d8729..ac5fed8a544e4 100644
--- a/server/http_status.go
+++ b/server/http_status.go
@@ -68,6 +68,34 @@ func sleepWithCtx(ctx context.Context, d time.Duration) {
 	}
 }
 
+func (s *Server) listenStatusHTTPServer() error {
+	s.statusAddr = fmt.Sprintf("%s:%d", s.cfg.Status.StatusHost, s.cfg.Status.StatusPort)
+	if s.cfg.Status.StatusPort == 0 {
+		s.statusAddr = fmt.Sprintf("%s:%d", s.cfg.Status.StatusHost, defaultStatusPort)
+	}
+
+	var err error
+	logutil.Logger(context.Background()).Info("for status and metrics report", zap.String("listening on addr", s.statusAddr))
+	s.statusListener, err = net.Listen("tcp", s.statusAddr)
+	if err != nil {
+		logutil.Logger(context.Background()).Info("listen failed", zap.Error(err))
+		return errors.Trace(err)
+	}
+
+	if len(s.cfg.Security.ClusterSSLCA) != 0 {
+		tlsConfig, err := s.cfg.Security.ToTLSConfig()
+		if err != nil {
+			logutil.Logger(context.Background()).Error("invalid TLS config", zap.Error(err))
+			return errors.Trace(err)
+		}
+		tlsConfig = s.setCNChecker(tlsConfig)
+		logutil.Logger(context.Background()).Info("HTTP/gRPC status server secure connection is enabled", zap.Bool("CN verification enabled", tlsConfig.VerifyPeerCertificate != nil))
+		s.statusListener = tls.NewListener(s.statusListener, tlsConfig)
+	}
+
+	return nil
+}
+
 func (s *Server) startHTTPServer() {
 	router := mux.NewRouter()
 
@@ -113,13 +141,9 @@ func (s *Server) startHTTPServer() {
 		router.Handle("/mvcc/hex/{hexKey}", mvccTxnHandler{tikvHandlerTool, opMvccGetByHex})
 		router.Handle("/mvcc/index/{db}/{table}/{index}/{handle}", mvccTxnHandler{tikvHandlerTool, opMvccGetByIdx})
 	}
-	addr := fmt.Sprintf("%s:%d", s.cfg.Status.StatusHost, s.cfg.Status.StatusPort)
-	if s.cfg.Status.StatusPort == 0 {
-		addr = fmt.Sprintf("%s:%d", s.cfg.Status.StatusHost, defaultStatusPort)
-	}
 
 	// HTTP path for web UI.
-	if host, port, err := net.SplitHostPort(addr); err == nil {
+	if host, port, err := net.SplitHostPort(s.statusAddr); err == nil {
 		if host == "" {
 			host = "localhost"
 		}
@@ -255,27 +279,8 @@ func (s *Server) startHTTPServer() {
 		}
 	})
 
-	logutil.Logger(context.Background()).Info("for status and metrics report", zap.String("listening on addr", addr))
-	s.statusServer = &http.Server{Addr: addr, Handler: CorsHandler{handler: serverMux, cfg: s.cfg}}
-
-	ln, err := net.Listen("tcp", addr)
-	if err != nil {
-		logutil.Logger(context.Background()).Info("listen failed", zap.Error(err))
-		return
-	}
-
-	if len(s.cfg.Security.ClusterSSLCA) != 0 {
-		tlsConfig, err := s.cfg.Security.ToTLSConfig()
-		if err != nil {
-			logutil.Logger(context.Background()).Error("invalid TLS config", zap.Error(err))
-			return
-		}
-		tlsConfig = s.setCNChecker(tlsConfig)
-		logutil.Logger(context.Background()).Info("HTTP/gRPC status server secure connection is enabled", zap.Bool("CN verification enabled", tlsConfig.VerifyPeerCertificate != nil))
-		ln = tls.NewListener(ln, tlsConfig)
-	}
-
-	err = s.statusServer.Serve(ln)
+	s.statusServer = &http.Server{Addr: s.statusAddr, Handler: CorsHandler{handler: serverMux, cfg: s.cfg}}
+	err = s.statusServer.Serve(s.statusListener)
 	if err != nil {
 		logutil.Logger(context.Background()).Info("serve status port failed", zap.Error(err))
 	}
diff --git a/server/server.go b/server/server.go
index 7ef8d39f9c5df..1f51d1998043a 100644
--- a/server/server.go
+++ b/server/server.go
@@ -112,6 +112,8 @@ type Server struct {
 	concurrentLimiter *TokenLimiter
 	clients           map[uint32]*clientConn
 	capability        uint32
+	statusAddr        string
+	statusListener    net.Listener
 	statusServer      *http.Server
 }
 
@@ -247,6 +249,9 @@ func NewServer(cfg *config.Config, driver IDriver) (*Server, error) {
 		s.listener = pplistener
 	}
 
+	if s.cfg.Status.ReportStatus && err == nil {
+		err = s.listenStatusHTTPServer()
+	}
 	if err != nil {
 		return nil, errors.Trace(err)
 	}
diff --git a/server/tidb_test.go b/server/tidb_test.go
index 2441bab9dfd02..0b0b37ff6ecef 100644
--- a/server/tidb_test.go
+++ b/server/tidb_test.go
@@ -160,6 +160,19 @@ func (ts *TidbTestSuite) TestStatusAPI(c *C) {
 	runTestStatusAPI(c)
 }
 
+func (ts *TidbTestSuite) TestStatusPort(c *C) {
+	cfg := config.NewConfig()
+	cfg.Port = 4008
+	cfg.Status.ReportStatus = true
+	cfg.Status.StatusPort = 10090
+
+	server, err := NewServer(cfg, ts.tidbdrv)
+	c.Assert(err, NotNil)
+	c.Assert(err.Error(), Equals,
+		fmt.Sprintf("listen tcp 0.0.0.0:%d: bind: address already in use", cfg.Status.StatusPort))
+	c.Assert(server, IsNil)
+}
+
 func (ts *TidbTestSuite) TestStatusAPIWithTLSCNCheck(c *C) {
 	caPath := filepath.Join(os.TempDir(), "ca-cert-cn.pem")
 	serverKeyPath := filepath.Join(os.TempDir(), "server-key-cn.pem")