server: if status address already in use, return an error (#15177)

server/http_status.go

@@ -71,6 +71,33 @@ 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)
+	}
+
+	logutil.BgLogger().Info("for status and metrics report", zap.String("listening on addr", s.statusAddr))
+	tlsConfig, err := s.cfg.Security.ToTLSConfig()
+	if err != nil {
+		logutil.BgLogger().Error("invalid TLS config", zap.Error(err))
+		return errors.Trace(err)
+	}
+	tlsConfig = s.setCNChecker(tlsConfig)
+
+	if tlsConfig != nil {
+		// we need to manage TLS here for cmux to distinguish between HTTP and gRPC.
+		s.statusListener, err = tls.Listen("tcp", s.statusAddr, tlsConfig)
+	} else {
+		s.statusListener, err = net.Listen("tcp", s.statusAddr)
+	}
+	if err != nil {
+		logutil.BgLogger().Info("listen failed", zap.Error(err))
+		return errors.Trace(err)
+	}
+	return nil
+}
+
 func (s *Server) startHTTPServer() {
 	router := mux.NewRouter()
 
@@ -123,13 +150,8 @@ 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"
 		}
@@ -271,40 +293,17 @@ func (s *Server) startHTTPServer() {
 			logutil.BgLogger().Error("write HTTP index page failed", zap.Error(err))
 		}
 	})
-
-	logutil.BgLogger().Info("for status and metrics report", zap.String("listening on addr", addr))
-	s.setupStatusServerAndRPCServer(addr, serverMux)
+	s.startStatusServerAndRPCServer(serverMux)
 }
 
-func (s *Server) setupStatusServerAndRPCServer(addr string, serverMux *http.ServeMux) {
-	tlsConfig, err := s.cfg.Security.ToTLSConfig()
-	if err != nil {
-		logutil.BgLogger().Error("invalid TLS config", zap.Error(err))
-		return
-	}
-	tlsConfig = s.setCNChecker(tlsConfig)
-
-	var l net.Listener
-	if tlsConfig != nil {
-		// we need to manage TLS here for cmux to distinguish between HTTP and gRPC.
-		l, err = tls.Listen("tcp", addr, tlsConfig)
-	} else {
-		l, err = net.Listen("tcp", addr)
-	}
-	if err != nil {
-		logutil.BgLogger().Info("listen failed", zap.Error(err))
-		return
-	}
-	if tlsConfig != nil {
-		logutil.BgLogger().Info("HTTP/gRPC status server secure connection is enabled", zap.Bool("CN verification enabled", tlsConfig.VerifyPeerCertificate != nil))
-	}
-	m := cmux.New(l)
+func (s *Server) startStatusServerAndRPCServer(serverMux *http.ServeMux) {
+	m := cmux.New(s.statusListener)
 	// Match connections in order:
 	// First HTTP, and otherwise grpc.
 	httpL := m.Match(cmux.HTTP1Fast())
 	grpcL := m.Match(cmux.Any())
 
-	s.statusServer = &http.Server{Addr: addr, Handler: CorsHandler{handler: serverMux, cfg: s.cfg}}
+	s.statusServer = &http.Server{Addr: s.statusAddr, Handler: CorsHandler{handler: serverMux, cfg: s.cfg}}
 	s.grpcServer = NewRPCServer(s.cfg, s.dom, s)
 
 	go util.WithRecovery(func() {
@@ -317,7 +316,7 @@ func (s *Server) setupStatusServerAndRPCServer(addr string, serverMux *http.Serv
 		logutil.BgLogger().Error("http server error", zap.Error(err))
 	}, nil)
 
-	err = m.Serve()
+	err := m.Serve()
 	if err != nil {
 		logutil.BgLogger().Error("start status/rpc server error", zap.Error(err))
 	}

server/server.go

@@ -116,8 +116,11 @@ type Server struct {
 	clients           map[uint32]*clientConn
 	capability        uint32
 	dom               *domain.Domain
-	statusServer      *http.Server
-	grpcServer        *grpc.Server
+
+	statusAddr     string
+	statusListener net.Listener
+	statusServer   *http.Server
+	grpcServer     *grpc.Server
 }
 
 // ConnectionCount gets current connection count.
@@ -256,6 +259,9 @@ 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)
 	}

server/tidb_test.go

@@ -22,6 +22,7 @@ import (
 	"crypto/x509"
 	"crypto/x509/pkix"
 	"encoding/pem"
+	"fmt"
 	"io/ioutil"
 	"math/big"
 	"net/http"
@@ -180,6 +181,27 @@ func (ts *tidbTestSuite) TestStatusAPI(c *C) {
 	ts.runTestStatusAPI(c)
 }
 
+func (ts *tidbTestSuite) TestStatusPort(c *C) {
+	var err error
+	ts.store, err = mockstore.NewMockTikvStore()
+	session.DisableStats4Test()
+	c.Assert(err, IsNil)
+	ts.domain, err = session.BootstrapSession(ts.store)
+	c.Assert(err, IsNil)
+	ts.tidbdrv = NewTiDBDriver(ts.store)
+	cfg := config.NewConfig()
+	cfg.Port = genPort()
+	cfg.Status.ReportStatus = true
+	cfg.Status.StatusPort = ts.statusPort
+	cfg.Performance.TCPKeepAlive = true
+
+	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", ts.statusPort))
+	c.Assert(server, IsNil)
+}
+
 func (ts *tidbTestSuite) TestStatusAPIWithTLS(c *C) {
 	caCert, caKey, err := generateCert(0, "TiDB CA 2", nil, nil, "/tmp/ca-key-2.pem", "/tmp/ca-cert-2.pem")
 	c.Assert(err, IsNil)