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Azure Event Hubs binding spec

Detailed documentation on the Azure Event Hubs binding component

Component format

To setup an Azure Event Hubs binding, create a component of type bindings.azure.eventhubs. See this guide on how to create and apply a binding configuration.

See this for instructions on how to set up an Event Hub.

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: <NAME>
spec:
  type: bindings.azure.eventhubs
  version: v1
  metadata:
    # Hub name ("topic")
    - name: eventHub
      value: "mytopic"
    - name: consumerGroup
      value: "myapp"
    # Either connectionString or eventHubNamespace is required
    # Use connectionString when *not* using Azure AD
    - name: connectionString
      value: "Endpoint=sb://{EventHubNamespace}.servicebus.windows.net/;SharedAccessKeyName={PolicyName};SharedAccessKey={Key};EntityPath={EventHub}"
    # Use eventHubNamespace when using Azure AD
    - name: eventHubNamespace
      value: "namespace"
    - name: enableEntityManagement
      value: "false"
    # The following four properties are needed only if enableEntityManagement is set to true
    - name: resourceGroupName
      value: "test-rg"
    - name: subscriptionID
      value: "value of Azure subscription ID"
    - name: partitionCount
      value: "1"
    - name: messageRetentionInDays
      value: "3"
    # Checkpoint store attributes
    - name: storageAccountName
      value: "myeventhubstorage"
    - name: storageAccountKey
      value: "112233445566778899"
    - name: storageContainerName
      value: "myeventhubstoragecontainer"
    # Alternative to passing storageAccountKey
    - name: storageConnectionString
      value: "DefaultEndpointsProtocol=https;AccountName=<account>;AccountKey=<account-key>"
    # Optional metadata
    - name: direction
      value: "input, output"

Spec metadata fields

Field Required Binding support Details Example
eventHub Y* Input/Output The name of the Event Hubs hub (“topic”). Required if using Azure AD authentication or if the connection string doesn’t contain an EntityPath value mytopic
connectionString Y* Input/Output Connection string for the Event Hub or the Event Hub namespace.
* Mutally exclusive with eventHubNamespace field.
* Required when not using Azure AD Authentication		 "Endpoint=sb://{EventHubNamespace}.servicebus.windows.net/;SharedAccessKeyName={PolicyName};SharedAccessKey={Key};EntityPath={EventHub}" or "Endpoint=sb://{EventHubNamespace}.servicebus.windows.net/;SharedAccessKeyName={PolicyName};SharedAccessKey={Key}"
eventHubNamespace Y* Input/Output The Event Hub Namespace name.
* Mutally exclusive with connectionString field.
* Required when using Azure AD Authentication		 "namespace"
enableEntityManagement N Input/Output Boolean value to allow management of the EventHub namespace and storage account. Default: false "true", "false"
resourceGroupName N Input/Output Name of the resource group the Event Hub namespace is part of. Required when entity management is enabled "test-rg"
subscriptionID N Input/Output Azure subscription ID value. Required when entity management is enabled "azure subscription id"
partitionCount N Input/Output Number of partitions for the new Event Hub namespace. Used only when entity management is enabled. Default: "1" "2"
messageRetentionInDays N Input/Output Number of days to retain messages for in the newly created Event Hub namespace. Used only when entity management is enabled. Default: "1" "90"
consumerGroup Y Input The name of the Event Hubs Consumer Group to listen on "group1"
storageAccountName Y Input Storage account name to use for the checkpoint store. "myeventhubstorage"
storageAccountKey Y* Input Storage account key for the checkpoint store account.
* When using Azure AD, it’s possible to omit this if the service principal has access to the storage account too.		 "112233445566778899"
storageConnectionString Y* Input Connection string for the checkpoint store, alternative to specifying storageAccountKey "DefaultEndpointsProtocol=https;AccountName=myeventhubstorage;AccountKey=<account-key>"
storageContainerName Y Input Storage container name for the storage account name. "myeventhubstoragecontainer"
direction N Input/Output The direction of the binding. "input", "output", "input, output"

Azure Active Directory (AAD) authentication

The Azure Event Hubs pub/sub component supports authentication using all Azure Active Directory mechanisms. For further information and the relevant component metadata fields to provide depending on the choice of AAD authentication mechanism, see the docs for authenticating to Azure.

Binding support

This component supports output binding with the following operations:

  • create: publishes a new message to Azure Event Hubs

Input Binding to Azure IoT Hub Events

Azure IoT Hub provides an endpoint that is compatible with Event Hubs, so Dapr apps can create input bindings to read Azure IoT Hub events using the Event Hubs bindings component.

The device-to-cloud events created by Azure IoT Hub devices will contain additional IoT Hub System Properties, and the Azure Event Hubs binding for Dapr will return the following as part of the response metadata:

System Property Name Description & Routing Query Keyword
iothub-connection-auth-generation-id The connectionDeviceGenerationId of the device that sent the message. See IoT Hub device identity properties.
iothub-connection-auth-method The connectionAuthMethod used to authenticate the device that sent the message.
iothub-connection-device-id The deviceId of the device that sent the message. See IoT Hub device identity properties.
iothub-connection-module-id The moduleId of the device that sent the message. See IoT Hub device identity properties.
iothub-enqueuedtime The enqueuedTime in RFC3339 format that the device-to-cloud message was received by IoT Hub.
message-id The user-settable AMQP messageId.

For example, the headers of a HTTP Read() response would contain:

{
  'user-agent': 'fasthttp',
  'host': '127.0.0.1:3000',
  'content-type': 'application/json',
  'content-length': '120',
  'iothub-connection-device-id': 'my-test-device',
  'iothub-connection-auth-generation-id': '637618061680407492',
  'iothub-connection-auth-method': '{"scope":"module","type":"sas","issuer":"iothub","acceptingIpFilterRule":null}',
  'iothub-connection-module-id': 'my-test-module-a',
  'iothub-enqueuedtime': '2021-07-13T22:08:09Z',
  'message-id': 'my-custom-message-id',
  'x-opt-sequence-number': '35',
  'x-opt-enqueued-time': '2021-07-13T22:08:09Z',
  'x-opt-offset': '21560',
  'traceparent': '00-4655608164bc48b985b42d39865f3834-ed6cf3697c86e7bd-01'
}

Last modified July 31, 2023: [Bindings] Update specs to include `direction` (#3646) (e33f5a95)