feat: Support using connection strings for Event Hub namespace instea…

…d of the Event Hub itself. (kedacore#3924)

Signed-off-by: Vighnesh Shenoy <vshenoy@microsoft.com>

CHANGELOG.md

@@ -63,6 +63,7 @@ To learn more about active deprecations, we recommend checking [GitHub Discussio
 - **Apache Kafka Scaler:** Limit Kafka Partitions KEDA operates on ([#3830](https://github.com/kedacore/keda/issues/3830))
 - **Azure AD Pod Identity Authentication:** Improve error messages to emphasize problems around the integration with aad-pod-identity itself ([#3610](https://github.com/kedacore/keda/issues/3610))
 - **Azure Event Hub Scaler:** Support Azure Active Direcotry Pod & Workload Identity for Storage Blobs ([#3569](https://github.com/kedacore/keda/issues/3569))
+- **Azure Event Hub Scaler:** Support using connection strings for Event Hub namespace instead of the Event Hub itself. ([#3922](https://github.com/kedacore/keda/issues/3922))
 - **Azure Pipelines Scaler:** Improved speed of profiling large set of Job Requests from Azure Pipelines ([#3702](https://github.com/kedacore/keda/issues/3702))
 - **GCP Storage Scaler:** Add prefix and delimiter support ([#3756](https://github.com/kedacore/keda/issues/3756))
 - **Metrics API Scaler:** Add unsafeSsl paramater to skip certificate validation when connecting over HTTPS ([#3728](https://github.com/kedacore/keda/discussions/3728))

Makefile

@@ -139,8 +139,8 @@ clientset-generate: ## Generate client-go clientset, listers and informers.
 	./hack/update-codegen.sh
 
 proto-gen: protoc-gen ## Generate Liiklus, ExternalScaler and MetricsService proto
-	PATH=$(LOCALBIN):$(PATH) protoc -I vendor --proto_path=hack LiiklusService.proto --go_out=pkg/scalers/liiklus --go-grpc_out=pkg/scalers/liiklus
-	PATH=$(LOCALBIN):$(PATH) protoc -I vendor --proto_path=pkg/scalers/externalscaler externalscaler.proto --go_out=pkg/scalers/externalscaler --go-grpc_out=pkg/scalers/externalscaler
+	PATH="$(LOCALBIN):$(PATH)" protoc -I vendor --proto_path=hack LiiklusService.proto --go_out=pkg/scalers/liiklus --go-grpc_out=pkg/scalers/liiklus
+	PATH="$(LOCALBIN):$(PATH)" protoc -I vendor --proto_path=pkg/scalers/externalscaler externalscaler.proto --go_out=pkg/scalers/externalscaler --go-grpc_out=pkg/scalers/externalscaler
 
 .PHONY: mockgen-gen
 mockgen-gen: mockgen pkg/mock/mock_scaling/mock_interface.go pkg/mock/mock_scaler/mock_scaler.go pkg/mock/mock_scale/mock_interfaces.go pkg/mock/mock_client/mock_interfaces.go pkg/scalers/liiklus/mocks/mock_liiklus.go

pkg/scalers/azure_eventhub_scaler.go

@@ -193,15 +193,33 @@ func parseAzureEventHubAuthenticationMetadata(logger logr.Logger, config *Scaler
 			return fmt.Errorf("no storage connection string given")
 		}
 
+		connection := ""
 		if config.AuthParams["connection"] != "" {
-			meta.eventHubInfo.EventHubConnection = config.AuthParams["connection"]
+			connection = config.AuthParams["connection"]
 		} else if config.TriggerMetadata["connectionFromEnv"] != "" {
-			meta.eventHubInfo.EventHubConnection = config.ResolvedEnv[config.TriggerMetadata["connectionFromEnv"]]
+			connection = config.ResolvedEnv[config.TriggerMetadata["connectionFromEnv"]]
 		}
 
-		if len(meta.eventHubInfo.EventHubConnection) == 0 {
+		if len(connection) == 0 {
 			return fmt.Errorf("no event hub connection string given")
 		}
+
+		if !strings.Contains(connection, "EntityPath") {
+			eventHubName := ""
+			if config.TriggerMetadata["eventHubName"] != "" {
+				eventHubName = config.TriggerMetadata["eventHubName"]
+			} else if config.TriggerMetadata["eventHubNameFromEnv"] != "" {
+				eventHubName = config.ResolvedEnv[config.TriggerMetadata["eventHubNameFromEnv"]]
+			}
+
+			if eventHubName == "" {
+				return fmt.Errorf("connection string does not contain event hub name, and parameter eventHubName not provided")
+			}
+
+			connection = fmt.Sprintf("%s;EntityPath=%s", connection, eventHubName)
+		}
+
+		meta.eventHubInfo.EventHubConnection = connection
 	case v1alpha1.PodIdentityProviderAzure, v1alpha1.PodIdentityProviderAzureWorkload:
 		meta.eventHubInfo.StorageAccountName = ""
 		if val, ok := config.TriggerMetadata["storageAccountName"]; ok {