Azure Event Hubs¶

Azure Event Hubs Trigger allows a sensor to publish events to Azure Event Hubs. Argo Events integrates with Azure Event Hubs to stream data from an EventSource

NOTE: Parametrization for fqdn and hubName values are not yet supported.

Specification¶

The Azure Event Hubs trigger specification is available here.

Send an Event to Azure Event Hubs¶

Make sure to have the eventbus deployed in the namespace.
Create an event hub.
Make sure that the Shared Access Key used to connect to Azure Event Hubs has the Send policy.
Get the Primary Key of the Shared Access Policy, the Name of the Shared Access Policy, the Hub Name, and the FQDN of the Azure Event Hubs Namespace.

Create a secret called azure-event-hubs-secret as follows:

NOTE: sharedAccessKey refers to the Primary Key and sharedAccessKeyName refers to the Name of the Shared Access Policy.

apiVersion: v1
kind: Secret
metadata:
  name: azure-event-hubs-secret
type: Opaque
data:
  sharedAccessKey: <base64-shared-access-key>
  sharedAccessKeyName: <base64-shared-access-key-name>

Let's set up a webhook event-source to process incoming requests.

kubectl apply -n argo-events -f https://raw.githubusercontent.com/argoproj/argo-events/stable/examples/event-sources/webhook.yaml

Create the sensor with the following template. Replace the necessary values for fqdn and hubName:

apiVersion: argoproj.io/v1alpha1
kind: Sensor
metadata:
  name: azure-events-hub
spec:
  dependencies:
    - name: test-dep
      eventSourceName: webhook
      eventName: example
  triggers:
    - template:
      name: azure-eventhubs-trigger
      azureEventHubs:
      # FQDN of the EventsHub namespace you created
      # More info at https://docs.microsoft.com/en-us/azure/event-hubs/event-hubs-get-connection-string
        fqdn: eventhubs_fqdn
        sharedAccessKeyName:
          name: azure-event-hubs-secret
          key: sharedAccessKeyName
        sharedAccessKey:
          name: azure-event-hubs-secret
          key: sharedAccessKey
        # Event Hub path/name
        hubName: hub_name
        payload:
          - src:
              dependencyName: test-dep
              dataKey: body.message
            dest: message

The Event needs a body. In order to construct a messaged based on your event data, the Azure Event Hubs sensor has the payload field as part of the trigger.

The payload contains the list of src which refers to the source events and dest which refers to destination key within the resulting request payload.

The payload declared above will generate a message body like below,
```
 {
     "message": "some message here" // name/key of the object
 }
```
Let's expose the webhook event-source pod using port-forward so that we can make a request to it.
```
kubectl -n argo-events port-forward <name-of-event-source-pod> 12000:12000
```

Use either Curl or Postman to send a post request to the http://localhost:12000/example.

curl -d '{"message":"ok"}' -H "Content-Type: application/json" -X POST http://localhost:12000/example

Verify Events have been in ingested in Azure Events Hub by creating a listener app or following other code samples. You can optionally create an Azure Event Hubs Event Source.