fix: reassign err to prevent invalid return in KedaProvider `GetExter…

…nalMetric` (#6010)

Signed-off-by: Max Cao <macao@redhat.com>

CHANGELOG.md

@@ -89,6 +89,7 @@ Here is an overview of all new **experimental** features:
 ### Fixes
 
 - **General**: Check for missing CRD references and sample CRs ([#5920](https://github.com/kedacore/keda/issues/5920))
+- **General**: Fix panic in `KedaProvider` when getting metrics from Metrics Service if the gRPC Server connection is not established ([#6009](https://github.com/kedacore/keda/issues/6009))
 - **General**: Scalers are properly closed after being refreshed ([#5806](https://github.com/kedacore/keda/issues/5806))
 - **New Relic Scaler**: Fix CVE-2024-6104 in github.com/hashicorp/go-retryablehttp ([#5944](https://github.com/kedacore/keda/issues/5944))
 

pkg/provider/provider.go

@@ -86,7 +86,8 @@ func (p *KedaProvider) GetExternalMetric(ctx context.Context, namespace string,
 	// Get Metrics from Metrics Service gRPC Server
 	if !p.grpcClient.WaitForConnectionReady(ctx, logger) {
 		grpcClientConnected = false
-		logger.Error(fmt.Errorf("timeout while waiting to establish gRPC connection to KEDA Metrics Service server"), "timeout", "server", p.grpcClient.GetServerURL())
+		err := fmt.Errorf("timeout while waiting to establish gRPC connection to KEDA Metrics Service server")
+		logger.Error(err, "timeout", "server", p.grpcClient.GetServerURL())
 		return nil, err
 	}
 	if !grpcClientConnected {