Azure - trigger notification from service bus queue

Question

I am trying to create the following process:

An IoT device sends a message to the IoT Hub which in turn, if the message contains some value, triggers a notification to all of the registered android devices through the Notification Hub.

At first, I do not care what is the content of the message itself, and I just want to trigger a notification on every incoming message.

I have managed to set up the IoT device and connect it to the IoT hub. I have also managed to set up the Notification Hub, and connect it with the android app, in a way that when I use the "test send" in the Notification Hub, a notification is received on the android device.

In order to connect both ends (IoT Hub and Notification Hub), I tried to follow the following tutorial: https://www.developer.com/ws/android/sending-notifications-to-mobile-apps-from-azure-function-apps.html

In addition, I have added routing from the IoT Hub to the appropriate queue in the service bus.

Now, whenever the IoT device sends a message to the hub, I can see that the queue receives a message. However, I can't seem to use the queue to trigger the notification.

The ServiceHubQueueTrigger function I have added has the following error in the portal:

Error:

Function (ServiceBusQueueTrigger1) Error: The binding type(s) 'notificationHub' are not registered. Please ensure the type is correct and the binding extension is installed.

Its function.json looks like this:

{
  "bindings": [
    {
      "name": "myQueueItem",
      "type": "serviceBusTrigger",
      "direction": "in",
      "queueName": "notificationqueue",
      "connection": "ServiceBusConnection",
      "accessRights": "manage"
    },
    {
      "name": "notification",
      "type": "notificationHub",
      "hubName": "<hub-name>",
      "connection": "NotificationConnString",
      "platform": "gcm",
      "tagExpression": "",
      "direction": "out"
    }
  ]
}

where hub-name is the name of the Notification Hub.

How can I trigger the notifications to the android devices through the queue? Is there a way to trigger them directly from an IoT Hub Event Trigger function?

Thanks!

silent silent · Accepted Answer · 2019-05-28T15:46:46

Yes, you can trigger an Azure Function directly from incoming IoT Hub events. See one of my samples here: https://github.com/sebader/iotedge-end2end/blob/master/CloudFunctions/IotHubMessageProcessor.cs

public static void Run([IoTHubTrigger("messages/events", Connection = "iothubevents_cs", ConsumerGroup = "receiverfunction")]EventData message, ILogger log)
{
  log.LogInformation($"IotHubMessageProcessor received a message: {Encoding.UTF8.GetString(message.Body.Array)}");
}

IoT Hub Function Binding: https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-event-iot

Azure - trigger notification from service bus queue

2 Answers