Add capability to set loglevel to trace during runtime

Signed-off-by: Arpad Kiss <arpad.a.kiss@est.tech>

main.go

@@ -103,11 +103,7 @@ func main() {
 		logrus.Fatalf("error processing config from env: %+v", err)
 	}
 
-	l, err := logrus.ParseLevel(config.LogLevel)
-	if err != nil {
-		logrus.Fatalf("invalid log level %s", config.LogLevel)
-	}
-	logrus.SetLevel(l)
+	setupLogLevel(ctx, config.LogLevel)
 
 	log.FromContext(ctx).Infof("Config: %#v", config)
 
@@ -118,7 +114,7 @@ func main() {
 		metricExporter := opentelemetry.InitOPTLMetricExporter(ctx, collectorAddress, config.MetricsExportInterval)
 		o := opentelemetry.Init(ctx, spanExporter, metricExporter, "registry-proxy-dns")
 		defer func() {
-			if err = o.Close(); err != nil {
+			if err := o.Close(); err != nil {
 				log.FromContext(ctx).Error(err.Error())
 			}
 		}()
@@ -196,3 +192,15 @@ func exitOnErr(ctx context.Context, cancel context.CancelFunc, errCh <-chan erro
 		cancel()
 	}(ctx, errCh)
 }
+
+func setupLogLevel(ctx context.Context, logLevel string) {
+	l, err := logrus.ParseLevel(logLevel)
+	if err != nil {
+		logrus.Fatalf("invalid log level %s", logLevel)
+	}
+	logrus.SetLevel(l)
+	logruslogger.SetupLevelChangeOnSignal(ctx, map[os.Signal]logrus.Level{
+		syscall.SIGUSR1: logrus.TraceLevel,
+		syscall.SIGUSR2: l,
+	})
+}