check that ScaledObject name is specified as part of a query for gett…

…ing metrics (#4097)

Signed-off-by: Zbynek Roubalik <zroubalik@gmail.com>

Signed-off-by: Zbynek Roubalik <zroubalik@gmail.com>

CHANGELOG.md

@@ -77,6 +77,7 @@ New deprecation(s):
 
 - **RabbitMQ Scaler:** Move from `streadway/amqp` to `rabbitmq/amqp091-go` ([#4004](https://github.com/kedacore/keda/pull/4039))
 - **General:** Compare error with `errors.Is` ([#4004](https://github.com/kedacore/keda/pull/4004))
+- **General:** Check that ScaledObject name is specified as part of a query for getting metrics ([#4088](https://github.com/kedacore/keda/pull/4088))
 
 ## v2.9.1
 

pkg/provider/provider.go

@@ -99,6 +99,12 @@ func (p *KedaProvider) GetExternalMetric(ctx context.Context, namespace string,
 
 		// selector is in form: `scaledobject.keda.sh/name: scaledobject-name`
 		scaledObjectName := selector.Get(kedav1alpha1.ScaledObjectOwnerAnnotation)
+		if scaledObjectName == "" {
+			err := fmt.Errorf("scaledObject name is not specified")
+			logger.Error(err, fmt.Sprintf("please specify scaledObject name, it needs to be set as value of label selector %q on the query", kedav1alpha1.ScaledObjectOwnerAnnotation))
+
+			return &external_metrics.ExternalMetricValueList{}, err
+		}
 
 		metrics, promMetrics, err := p.grpcClient.GetMetrics(ctx, scaledObjectName, namespace, info.Metric)
 		logger.V(1).WithValues("scaledObjectName", scaledObjectName, "scaledObjectNamespace", namespace, "metrics", metrics).Info("Receiving metrics")