Disable kine metrics by default

cmd/root.go

@@ -72,13 +72,26 @@ var (
 				}
 			}
 
+			var metricsServer *http.Server
+
 			if rootCmdOpts.metrics {
-				go func() {
-					logrus.WithField("address", rootCmdOpts.metricsAddress).Print("Enable metrics endpoint")
-					mux := http.NewServeMux()
+				metricsServer := &http.Server{
+					Addr:    rootCmdOpts.metricsAddress,
+					Handler: http.NewServeMux(),
+				}
+				mux, ok := metricsServer.Handler.(*http.ServeMux)
+				if !ok {
+					logrus.Fatal("Failed to create metrics endpoint")
+				} else {
 					mux.Handle("/metrics", promhttp.Handler())
-					http.ListenAndServe(rootCmdOpts.metricsAddress, mux)
-				}()
+
+					go func() {
+						logrus.WithField("address", rootCmdOpts.metricsAddress).Print("Enable metrics endpoint")
+						if err := metricsServer.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+							logrus.WithError(err).Fatal("Failed to start metrics endpoint")
+						}
+					}()
+				}
 			}
 
 			instance, err := server.New(
@@ -130,6 +143,11 @@ var (
 					logrus.WithError(err).Warning("Failed to shutdown OpenTelemetry SDK")
 				}
 			}
+			if rootCmdOpts.metrics && metricsServer != nil {
+				if err := metricsServer.Shutdown(stopCtx); err != nil {
+					logrus.WithError(err).Fatal("Failed to shutdown metrics endpoint")
+				}
+			}
 		},
 	}
 )
@@ -152,15 +170,15 @@ func init() {
 	rootCmd.Flags().BoolVar(&rootCmdOpts.diskMode, "disk-mode", false, "(experimental) run dqlite store in disk mode")
 	rootCmd.Flags().UintVar(&rootCmdOpts.clientSessionCacheSize, "tls-client-session-cache-size", 0, "ClientCacheSession size for dial TLS config")
 	rootCmd.Flags().StringVar(&rootCmdOpts.minTLSVersion, "min-tls-version", "tls12", "Minimum TLS version for dqlite endpoint (tls10|tls11|tls12|tls13). Default is tls12")
-	rootCmd.Flags().BoolVar(&rootCmdOpts.metrics, "metrics", true, "enable metrics endpoint")
+	rootCmd.Flags().BoolVar(&rootCmdOpts.metrics, "metrics", false, "enable metrics endpoint")
 	rootCmd.Flags().BoolVar(&rootCmdOpts.otel, "otel", false, "enable traces endpoint")
 	rootCmd.Flags().StringVar(&rootCmdOpts.otelAddress, "otel-listen", "127.0.0.1:4317", "listen address for OpenTelemetry endpoint")
 	rootCmd.Flags().StringVar(&rootCmdOpts.metricsAddress, "metrics-listen", "127.0.0.1:9042", "listen address for metrics endpoint")
 	rootCmd.Flags().DurationVar(&rootCmdOpts.watchAvailableStorageInterval, "watch-storage-available-size-interval", 5*time.Second, "Interval to check if the disk is running low on space. Set to 0 to disable the periodic disk size check")
 	rootCmd.Flags().Uint64Var(&rootCmdOpts.watchAvailableStorageMinBytes, "watch-storage-available-size-min-bytes", 10*1024*1024, "Minimum required available disk size (in bytes) to continue operation. If available disk space gets below this threshold, then the --low-available-storage-action is performed")
 	rootCmd.Flags().StringVar(&rootCmdOpts.lowAvailableStorageAction, "low-available-storage-action", "none", "Action to perform in case the available storage is low. One of (none|handover|terminate). none means no action is performed. handover means the dqlite node will handover its leadership role, if any. terminate means this dqlite node will shutdown")
 	rootCmd.Flags().StringVar(&rootCmdOpts.admissionControlPolicy, "admission-control-policy", "allow-all", "Transaction admission control policy to use. One of (allow-all|limit-concurrent-transactions). Set to allow-all to disable the admission control")
-	// TODO(MK-1408): This value is highly dependend on underlying hardware, thus making the default value a bit useless. The linked card will implement a dynamic way to set this value.
+	// TODO(MK-1408): This value is highly depends on underlying hardware, thus making the default value a bit useless. The linked card will implement a dynamic way to set this value.
 	rootCmd.Flags().Int64Var(&rootCmdOpts.acpLimitMaxConcurrentTxn, "admission-control-policy-limit-max-concurrent-transactions", 300, "Maximum number of transactions that are allowed to run concurrently. Transactions will not be admitted after the limit is reached.")
 	rootCmd.Flags().BoolVar(&rootCmdOpts.acpOnlyWriteQueries, "admission-control-only-for-write-queries", false, "If set, admission control will only be applied to write queries.")