Create and shutdown HTTP server (for metrics) gracefully

cmd/run.go

@@ -54,6 +54,7 @@ var (
 	globalConfigFile  string
 	conf              *config.Config
 	pluginRegistry    *plugin.Registry
+	metricsServer     *http.Server
 
 	UsageReportURL = "localhost:59091"
 
@@ -72,6 +73,7 @@ func StopGracefully(
 	pluginTimeoutCtx context.Context,
 	sig os.Signal,
 	metricsMerger *metrics.Merger,
+	metricsServer *http.Server,
 	pluginRegistry *plugin.Registry,
 	logger zerolog.Logger,
 	servers map[string]*network.Server,
@@ -110,6 +112,15 @@ func StopGracefully(
 		logger.Info().Msg("Stopped metrics merger")
 		span.AddEvent("Stopped metrics merger")
 	}
+	if metricsServer != nil {
+		if err := metricsServer.Shutdown(context.Background()); err != nil {
+			logger.Error().Err(err).Msg("Failed to stop metrics server")
+			span.RecordError(err)
+		} else {
+			logger.Info().Msg("Stopped metrics server")
+			span.AddEvent("Stopped metrics server")
+		}
+	}
 	for name, server := range servers {
 		logger.Info().Str("name", name).Msg("Stopping server")
 		server.Shutdown() //nolint:contextcheck
@@ -378,6 +389,7 @@ var runCmd = &cobra.Command{
 			if conf.Plugin.EnableMetricsMerger && metricsMerger != nil {
 				handler = mergedMetricsHandler(handler)
 			}
+
 			// Check if the metrics server is already running before registering the handler.
 			if _, err = http.Get(address); err != nil { //nolint:gosec
 				http.Handle(metricsConfig.Path, gziphandler.GzipHandler(handler))
@@ -386,9 +398,15 @@ var runCmd = &cobra.Command{
 				span.RecordError(err)
 			}
 
+			// Create a new metrics server.
+			metricsServer = &http.Server{
+				Addr:    metricsConfig.Address,
+				Handler: handler,
+			}
+
+			// Start the metrics server.
 			//nolint:gosec
-			if err = http.ListenAndServe(
-				metricsConfig.Address, nil); err != nil {
+			if err = metricsServer.ListenAndServe(); err != http.ErrServerClosed {
 				logger.Error().Err(err).Msg("Failed to start metrics server")
 				span.RecordError(err)
 			}
@@ -730,6 +748,7 @@ var runCmd = &cobra.Command{
 							pluginTimeoutCtx,
 							sig,
 							metricsMerger,
+							metricsServer,
 							pluginRegistry,
 							logger,
 							servers,

cmd/run_test.go

@@ -34,6 +34,7 @@ func Test_runCmd(t *testing.T) {
 			nil,
 			nil,
 			nil,
+			nil,
 			loggers[config.Default],
 			servers,
 			stopChan,
@@ -115,6 +116,7 @@ func Test_runCmdWithCachePlugin(t *testing.T) {
 			nil,
 			nil,
 			nil,
+			nil,
 			loggers[config.Default],
 			servers,
 			stopChan,