Add trace log to podmetrics and small warning fix to metrics_spec_test.

Author: BenjaminBraunDev

pkg/epp/backend/metrics/metrics_spec_test.go

@@ -159,7 +159,7 @@ func TestStringToMetricSpec(t *testing.T) {
 				}
 			} else {
 				if got == nil {
-					t.Errorf("stringToMetricSpec() = got nil but wanted %v", tt.want)
+					t.Fatalf("stringToMetricSpec() = got nil but wanted %v", tt.want)
 				}
 				if !reflect.DeepEqual(got.MetricName, tt.want.MetricName) {
 					t.Errorf("stringToMetricSpec() got MetricName = %v, want %v", got.MetricName, tt.want.MetricName)

pkg/epp/backend/metrics/pod_metrics.go

@@ -115,6 +115,7 @@ func (pm *podMetrics) refreshMetrics() error {
 	defer cancel()
 	updated, err := pm.pmc.FetchMetrics(ctx, pm.GetPod(), pm.GetMetrics(), pool.Spec.TargetPortNumber)
 	if err != nil {
+		pm.logger.V(logutil.TRACE).Info("Failed to refreshed metrics:", "err", err)
 		// As refresher is running in the background, it's possible that the pod is deleted but
 		// the refresh goroutine doesn't read the done channel yet. In this case, we just return nil.
 		// The refresher will be stopped after this interval.