Email alert using Event Grid & LogicApp with filters on telemetry fields

Question

Hello,

I am trying to use EventGrid and LogicApp for the first time. I have a few fundamental questions (might be trivial),

• Is this the best approach to instrument telemetry and trigger email?
• To add filters in EventGrid, I wanted to check the exact format of telemetry the IoTHub receives and sends it to EventGrid. If I look into activity logs, I dont see that. With some random try, I was able to set the filter. Example, data.body.temperature is greater than 50.
• Also for LogicApp schema, I would like to get the exact payload format the EventGrid receives so that I can attach the sample to generate schema.

I added a storage blob and redirect all my telemetry messages to the blob. (This is just for my learning) and I see the below format for each entry. So should I use this 'as is' to create the schema for LogicApp (Http Request)?

{
  "EnqueuedTimeUtc": "2023-06-01T11:54:44.3100000Z",
  "Properties": {},
  "SystemProperties": {
    "connectionDeviceId": "sagarlaptopvscode",
    "connectionAuthMethod": "{\"scope\":\"device\",\"type\":\"sas\",\"issuer\":\"iothub\",\"acceptingIpFilterRule\":null}",
    "connectionDeviceGenerationId": "638212049258571423",
    "contentType": "application/json",
    "contentEncoding": "utf-8",
    "enqueuedTime": "2023-06-01T11:54:44.3100000Z"
  },
  "Body": {
    "status": "fine",
    "temperature": 39
  }
}

Thanks

Answer 1

You can find the details of the schema of the messages that EventGrid receives here: https://learn.microsoft.com/azure/event-grid/event-schema-iot-hub?tabs=event-grid-event-schema

IoT Hub can route telemetry to other services in various ways. For an overview and comparison, see https://learn.microsoft.com/zure/iot-hub/iot-hub-devguide-messages-d2c