refactor: relocate run group initialization

Signed-off-by: Mark Sagi-Kazar <mark.sagikazar@gmail.com>

cmd/dex/serve.go

@@ -73,27 +73,6 @@ func commandServe() *cobra.Command {
 	return cmd
 }
 
-func listenAndShutdownGracefully(logger log.Logger, gr *run.Group, srv *http.Server, name string) error {
-	l, err := net.Listen("tcp", srv.Addr)
-	if err != nil {
-		return fmt.Errorf("listening (%s) on %s: %v", name, srv.Addr, err)
-	}
-
-	gr.Add(func() error {
-		logger.Infof("listening (%s) on %s", name, srv.Addr)
-		return srv.Serve(l)
-	}, func(err error) {
-		ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
-		defer cancel()
-
-		logger.Debugf("starting graceful shutdown (%s)", name)
-		if err := srv.Shutdown(ctx); err != nil {
-			logger.Errorf("graceful shutdown (%s): %v", name, err)
-		}
-	})
-	return nil
-}
-
 func runServe(options serveOptions) error {
 	configFile := options.config
 	configData, err := ioutil.ReadFile(configFile)
@@ -355,27 +334,77 @@ func runServe(options serveOptions) error {
 	})
 
 	var gr run.Group
+
+	// Set up telemetry server
 	if c.Telemetry.HTTP != "" {
-		telemetrySrv := &http.Server{Addr: c.Telemetry.HTTP, Handler: telemetryRouter}
+		const name = "telemetry"
+
+		logger.Infof("listening (%s) on %s", name, c.Telemetry.HTTP)
 
-		defer telemetrySrv.Close()
+		l, err := net.Listen("tcp", c.Telemetry.HTTP)
-		if err := listenAndShutdownGracefully(logger, &gr, telemetrySrv, "http/telemetry"); err != nil {
+		if err != nil {
-			return err
+			return fmt.Errorf("listening (%s) on %s: %v", name, c.Telemetry.HTTP, err)
+		}
+
+		server := &http.Server{
+			Handler: telemetryRouter,
 		}
+		defer server.Close()
+
+		gr.Add(func() error {
+			return server.Serve(l)
+		}, func(err error) {
+			ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+			defer cancel()
+
+			logger.Debugf("starting graceful shutdown (%s)", name)
+			if err := server.Shutdown(ctx); err != nil {
+				logger.Errorf("graceful shutdown (%s): %v", name, err)
+			}
+		})
 	}
 
+	// Set up http server
 	if c.Web.HTTP != "" {
-		httpSrv := &http.Server{Addr: c.Web.HTTP, Handler: serv}
+		const name = "http"
 
-		defer httpSrv.Close()
+		logger.Infof("listening (%s) on %s", name, c.Web.HTTP)
-		if err := listenAndShutdownGracefully(logger, &gr, httpSrv, "http"); err != nil {
+
-			return err
+		l, err := net.Listen("tcp", c.Web.HTTP)
+		if err != nil {
+			return fmt.Errorf("listening (%s) on %s: %v", name, c.Web.HTTP, err)
 		}
+
+		server := &http.Server{
+			Handler: serv,
+		}
+		defer server.Close()
+
+		gr.Add(func() error {
+			return server.Serve(l)
+		}, func(err error) {
+			ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+			defer cancel()
+
+			logger.Debugf("starting graceful shutdown (%s)", name)
+			if err := server.Shutdown(ctx); err != nil {
+				logger.Errorf("graceful shutdown (%s): %v", name, err)
+			}
+		})
 	}
 
+	// Set up https server
 	if c.Web.HTTPS != "" {
-		httpsSrv := &http.Server{
+		const name = "https"
-			Addr:    c.Web.HTTPS,
+
+		logger.Infof("listening (%s) on %s", name, c.Web.HTTPS)
+
+		l, err := net.Listen("tcp", c.Web.HTTPS)
+		if err != nil {
+			return fmt.Errorf("listening (%s) on %s: %v", name, c.Web.HTTPS, err)
+		}
+
+		server := &http.Server{
 			Handler: serv,
 			TLSConfig: &tls.Config{
 				CipherSuites:             allowedTLSCiphers,
@@ -383,14 +412,25 @@ func runServe(options serveOptions) error {
 				MinVersion:               tls.VersionTLS12,
 			},
 		}
+		defer server.Close()
 
-		defer httpsSrv.Close()
+		gr.Add(func() error {
-		if err := listenAndShutdownGracefully(logger, &gr, httpsSrv, "https"); err != nil {
+			return server.ServeTLS(l, c.Web.TLSCert, c.Web.TLSKey)
-			return err
+		}, func(err error) {
-		}
+			ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
+			defer cancel()
+
+			logger.Debugf("starting graceful shutdown (%s)", name)
+			if err := server.Shutdown(ctx); err != nil {
+				logger.Errorf("graceful shutdown (%s): %v", name, err)
+			}
+		})
 	}
 
+	// Set up grpc server
 	if c.GRPC.Addr != "" {
+		logger.Infof("listening (grpc) on %s", c.GRPC.Addr)
+
 		grpcListener, err := net.Listen("tcp", c.GRPC.Addr)
 		if err != nil {
 			return fmt.Errorf("listening (grcp) on %s: %w", c.GRPC.Addr, err)
@@ -406,7 +446,6 @@ func runServe(options serveOptions) error {
 		}
 
 		gr.Add(func() error {
-			logger.Infof("listening (grpc) on %s", c.GRPC.Addr)
 			return grpcSrv.Serve(grpcListener)
 		}, func(err error) {
 			logger.Debugf("starting graceful shutdown (grpc)")