Introduce Azure Event Grid as a new CloudEvent destination

CHANGELOG.md

@@ -59,7 +59,7 @@ To learn more about active deprecations, we recommend checking [GitHub Discussio
 
 Here is an overview of all new **experimental** features:
 
-- **General**: TODO ([#XXX](https://github.com/kedacore/keda/issues/XXX))
+- **General**: Introduce Azure Event Grid as a new CloudEvent destination ([#3587](https://github.com/kedacore/keda/issues/3587))
 
 ### Improvements
 

apis/eventing/v1alpha1/cloudeventsource_types.go

@@ -64,12 +64,21 @@ type CloudEventSourceStatus struct {
 type Destination struct {
 	// +optional
 	HTTP *CloudEventHTTP `json:"http"`
+
+	// +optional
+	AzureEventGrid *AzureEventGridSpec `json:"azureEventGrid"`
 }
 
 type CloudEventHTTP struct {
 	URI string `json:"uri"`
 }
 
+type AzureEventGridSpec struct {
+	EndPoint string `json:"endPoint"`
+
+	Key string `json:"key"`
+}
+
 func init() {
 	SchemeBuilder.Register(&CloudEventSource{}, &CloudEventSourceList{})
 }

config/crd/bases/eventing.keda.sh_cloudeventsources.yaml

@@ -49,6 +49,16 @@ spec:
               destination:
                 description: Destination defines the various ways to emit events
                 properties:
+                  azureEventGrid:
+                    properties:
+                      endPoint:
+                        type: string
+                      key:
+                        type: string
+                    required:
+                    - endPoint
+                    - key
+                    type: object
                   http:
                     properties:
                       uri:

go.mod

@@ -12,7 +12,7 @@ require (
 	github.com/Azure/azure-event-hubs-go/v3 v3.6.2
 	github.com/Azure/azure-kusto-go v0.15.0
 	github.com/Azure/azure-sdk-for-go v68.0.0+incompatible
-	github.com/Azure/azure-sdk-for-go/sdk/azcore v1.9.1
+	github.com/Azure/azure-sdk-for-go/sdk/azcore v1.10.0
 	github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.5.1
 	github.com/Azure/azure-sdk-for-go/sdk/messaging/azservicebus v1.6.0
 	github.com/Azure/azure-storage-blob-go v0.15.0
@@ -156,7 +156,8 @@ require (
 	cloud.google.com/go/iam v1.1.5 // indirect
 	code.cloudfoundry.org/clock v1.1.0 // indirect
 	github.com/Azure/azure-pipeline-go v0.2.3 // indirect
-	github.com/Azure/azure-sdk-for-go/sdk/internal v1.5.1 // indirect
+	github.com/Azure/azure-sdk-for-go/sdk/internal v1.5.2 // indirect
+	github.com/Azure/azure-sdk-for-go/sdk/messaging/azeventgrid v0.4.0
 	github.com/Azure/go-amqp v1.0.4 // indirect
 	github.com/Azure/go-autorest v14.2.0+incompatible // indirect
 	github.com/Azure/go-autorest/autorest/adal v0.9.23 // indirect
@@ -332,7 +333,7 @@ require (
 	golang.org/x/crypto v0.18.0
 	golang.org/x/exp v0.0.0-20240112132812-db7319d0e0e3 // indirect
 	golang.org/x/mod v0.14.0 // indirect
-	golang.org/x/net v0.20.0 // indirect
+	golang.org/x/net v0.21.0 // indirect
 	golang.org/x/sys v0.16.0 // indirect
 	golang.org/x/term v0.16.0 // indirect
 	golang.org/x/text v0.14.0 // indirect

go.sum

@@ -819,14 +819,16 @@ github.com/Azure/azure-pipeline-go v0.2.3/go.mod h1:x841ezTBIMG6O3lAcl8ATHnsOPVl
 github.com/Azure/azure-sdk-for-go v68.0.0+incompatible h1:fcYLmCpyNYRnvJbPerq7U0hS+6+I79yEDJBqVNcqUzU=
 github.com/Azure/azure-sdk-for-go v68.0.0+incompatible/go.mod h1:9XXNKU+eRnpl9moKnB4QOLf1HestfXbmab5FXxiDBjc=
 github.com/Azure/azure-sdk-for-go/sdk/azcore v0.19.0/go.mod h1:h6H6c8enJmmocHUbLiiGY6sx7f9i+X3m1CHdd5c6Rdw=
-github.com/Azure/azure-sdk-for-go/sdk/azcore v1.9.1 h1:lGlwhPtrX6EVml1hO0ivjkUxsSyl4dsiw9qcA1k/3IQ=
-github.com/Azure/azure-sdk-for-go/sdk/azcore v1.9.1/go.mod h1:RKUqNu35KJYcVG/fqTRqmuXJZYNhYkBrnC/hX7yGbTA=
+github.com/Azure/azure-sdk-for-go/sdk/azcore v1.10.0 h1:n1DH8TPV4qqPTje2RcUBYwtrTWlabVp4n46+74X2pn4=
+github.com/Azure/azure-sdk-for-go/sdk/azcore v1.10.0/go.mod h1:HDcZnuGbiyppErN6lB+idp4CKhjbc8gwjto6OPpyggM=
 github.com/Azure/azure-sdk-for-go/sdk/azidentity v0.11.0/go.mod h1:HcM1YX14R7CJcghJGOYCgdezslRSVzqwLf/q+4Y2r/0=
 github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.5.1 h1:sO0/P7g68FrryJzljemN+6GTssUXdANk6aJ7T1ZxnsQ=
 github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.5.1/go.mod h1:h8hyGFDsU5HMivxiS2iYFZsgDbU9OnnJ163x5UGVKYo=
 github.com/Azure/azure-sdk-for-go/sdk/internal v0.7.0/go.mod h1:yqy467j36fJxcRV2TzfVZ1pCb5vxm4BtZPUdYWe/Xo8=
-github.com/Azure/azure-sdk-for-go/sdk/internal v1.5.1 h1:6oNBlSdi1QqM1PNW7FPA6xOGA5UNsXnkaYZz9vdPGhA=
-github.com/Azure/azure-sdk-for-go/sdk/internal v1.5.1/go.mod h1:s4kgfzA0covAXNicZHDMN58jExvcng2mC/DepXiF1EI=
+github.com/Azure/azure-sdk-for-go/sdk/internal v1.5.2 h1:LqbJ/WzJUwBf8UiaSzgX7aMclParm9/5Vgp+TY51uBQ=
+github.com/Azure/azure-sdk-for-go/sdk/internal v1.5.2/go.mod h1:yInRyqWXAuaPrgI7p70+lDDgh3mlBohis29jGMISnmc=
+github.com/Azure/azure-sdk-for-go/sdk/messaging/azeventgrid v0.4.0 h1:d7S13DPk63SvBJfSUiMJJ26tRsvrBumkLPEfQEAarGk=
+github.com/Azure/azure-sdk-for-go/sdk/messaging/azeventgrid v0.4.0/go.mod h1:7e/gsXp4INB4k/vg0h3UOkYpDK6oZqctxr+L05FGybg=
 github.com/Azure/azure-sdk-for-go/sdk/messaging/azservicebus v1.6.0 h1:Fhg/LkAagiLv9Xpw6r2knr19tn9t1TiQoJu5bOMzflc=
 github.com/Azure/azure-sdk-for-go/sdk/messaging/azservicebus v1.6.0/go.mod h1:7xwz/6tTwO9zMKni8/EozIMi0DTexFSm7YNE9HdD3cQ=
 github.com/Azure/azure-storage-blob-go v0.15.0 h1:rXtgp8tN1p29GvpGgfJetavIG0V7OgcSXPpwp3tx6qk=

pkg/eventemitter/azure_event_grid_handler.go

@@ -0,0 +1,111 @@
+/*
+Copyright 2024 The KEDA Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// ******************************* DESCRIPTION ****************************** \\
+// AzureEventGridHandler focuses on emitting the CloudEventSource to Azure Event Grid
+// ************************************************************************** \\
+
+package eventemitter
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore"
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/messaging"
+	"github.com/Azure/azure-sdk-for-go/sdk/azcore/to"
+	"github.com/Azure/azure-sdk-for-go/sdk/messaging/azeventgrid/publisher"
+	"github.com/go-logr/logr"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
+	eventingv1alpha1 "github.com/kedacore/keda/v2/apis/eventing/v1alpha1"
+	"github.com/kedacore/keda/v2/pkg/eventemitter/eventdata"
+)
+
+type AzureEventGridHandler struct {
+	Endpoint     string
+	Key          string
+	ClusterName  string
+	Client       *publisher.Client
+	logger       logr.Logger
+	activeStatus metav1.ConditionStatus
+}
+
+func NewAzureEventGridHandler(clusterName string, spec *eventingv1alpha1.AzureEventGridSpec, logger logr.Logger) (*AzureEventGridHandler, error) {
+	client, err := publisher.NewClientWithSharedKeyCredential(spec.EndPoint, azcore.NewKeyCredential(spec.Key), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	logger.Info("Create new azure event grid handler")
+	return &AzureEventGridHandler{
+		Client:       client,
+		Endpoint:     spec.EndPoint,
+		Key:          spec.Key,
+		ClusterName:  clusterName,
+		logger:       logger,
+		activeStatus: metav1.ConditionTrue,
+	}, nil
+}
+
+func (a *AzureEventGridHandler) CloseHandler() {
+
+}
+
+func (a *AzureEventGridHandler) SetActiveStatus(status metav1.ConditionStatus) {
+	a.activeStatus = status
+}
+
+func (a *AzureEventGridHandler) GetActiveStatus() metav1.ConditionStatus {
+	return a.activeStatus
+}
+
+func (a *AzureEventGridHandler) EmitEvent(eventData eventdata.EventData, failureFunc func(eventData eventdata.EventData, err error)) {
+	type emitData struct {
+		Reason  string `json:"reason"`
+		Message string `json:"message"`
+	}
+
+	source := fmt.Sprintf("/%s/%s/keda", a.ClusterName, kedaNamespace)
+	subject := fmt.Sprintf("/%s/%s/%s/%s", a.ClusterName, eventData.Namespace, eventData.ObjectType, eventData.ObjectName)
+
+	opt := &messaging.CloudEventOptions{
+		Subject:         &subject,
+		DataContentType: to.Ptr("application/json"),
+		Time:            &eventData.Time,
+	}
+
+	event, err := messaging.NewCloudEvent(source, eventData.EventType, emitData{Reason: eventData.Reason, Message: eventData.Message}, opt)
+
+	if err != nil {
+		a.logger.Error(err, "EmitEvent error %s")
+		return
+	}
+
+	eventsToSend := []messaging.CloudEvent{
+		event,
+	}
+
+	_, err = a.Client.PublishCloudEvents(context.TODO(), eventsToSend, &publisher.PublishCloudEventsOptions{})
+
+	if err != nil {
+		a.logger.Error(err, "Failed to Publish Event to Azure Event Grid ")
+		failureFunc(eventData, err)
+		return
+	}
+
+	a.logger.Info("Publish Event to Azure Event Grid Successfully")
+}

pkg/eventemitter/eventemitter.go

@@ -86,7 +86,8 @@ type EmitData struct {
 }
 
 const (
-	cloudEventHandlerTypeHTTP = "http"
+	cloudEventHandlerTypeHTTP           = "http"
+	cloudEventHandlerTypeAzureEventGrid = "azureEventGrid"
 )
 
 // NewEventEmitter creates a new EventEmitter
@@ -188,6 +189,20 @@ func (e *EventEmitter) createEventHandlers(ctx context.Context, cloudEventSource
 		}
 		e.eventHandlersCache[eventHandlerKey] = eventHandler
 	}
+
+	if cloudEventSource.Spec.Destination.AzureEventGrid != nil {
+		eventHandler, err := NewAzureEventGridHandler(clusterName, cloudEventSource.Spec.Destination.AzureEventGrid, initializeLogger(cloudEventSource, "azure_event_grid"))
+		if err != nil {
+			e.log.Error(err, "create Azure Event Grid handler failed")
+			return
+		}
+
+		eventHandlerKey := newEventHandlerKey(key, cloudEventHandlerTypeAzureEventGrid)
+		if h, ok := e.eventHandlersCache[eventHandlerKey]; ok {
+			h.CloseHandler()
+		}
+		e.eventHandlersCache[eventHandlerKey] = eventHandler
+	}
 }
 
 // clearEventHandlersCache will clear all event handlers that created by the passing CloudEventSource
@@ -205,6 +220,14 @@ func (e *EventEmitter) clearEventHandlersCache(cloudEventSource *eventingv1alpha
 			delete(e.eventHandlersCache, key)
 		}
 	}
+
+	if cloudEventSource.Spec.Destination.AzureEventGrid != nil {
+		eventHandlerKey := newEventHandlerKey(key, cloudEventHandlerTypeAzureEventGrid)
+		if eventHandler, found := e.eventHandlersCache[eventHandlerKey]; found {
+			eventHandler.CloseHandler()
+			delete(e.eventHandlersCache, key)
+		}
+	}
 }
 
 // clearEventHandlersCache will check if the event handlers that were created by passing CloudEventSource exist
@@ -395,8 +418,7 @@ func (e *EventEmitter) updateCloudEventSourceStatus(ctx context.Context, cloudEv
 	return nil
 }
 
-// TODO: nolint:unparam should be remove after added more than one cloudevent handler
-func newEventHandlerKey(kindNamespaceName string, handlerType string) string { //nolint:unparam
+func newEventHandlerKey(kindNamespaceName string, handlerType string) string {
 	return fmt.Sprintf("%s.%s", kindNamespaceName, handlerType)
 }
 

tests/.env

@@ -23,6 +23,10 @@ TF_AZURE_MANAGED_PROMETHEUS_QUERY_ENDPOINT=
 TF_AZURE_RESOURCE_GROUP=
 TF_AZURE_SERVICE_BUS_CONNECTION_STRING=
 TF_AZURE_SP_APP_ID=
+TF_AZURE_SERVICE_BUS_EVENTGRID_CONNECTION_STRING=
+TF_AZURE_EVENT_GRID_ENDPOINT=
+TF_AZURE_EVENT_GRID_KEY=
+TF_AZURE_SB_EVENT_GRID_RECEIVE_TOPIC=
 AZURE_SP_KEY=
 TF_AZURE_SP_OBJECT_ID=
 TF_AZURE_SP_TENANT=