Azure Function Event Trigger client certificates

Question

I have a Function app with an endpoint that is event gird triggered and this trigger is falling with error if I enable the client certificate for my function. I would like to understand if (and in case how) I have to pass the certificate from event grid topic (that is generated from a blob file upload) to function subscriber or how to avoid having in Microsoft Defender Cloud this warning message: "Function apps should have Client Certificates (Incoming client certificates) enabled"

Thanks for support, Dave.

Answer 1

AFAIK, There's no method to pass the client certificate from event grid topic to Function subscriber.

In order for your Eventgrid to work with functions- The Azure Event Grid bindings for Azure Functions can be used to transfer the certificate from event grid topic to function subscriber. Once the extension bundle has been registered, You can install the Event Grid extension bundle version 2.x in your function app. In order to send events to the function, you may then use the Event Grid output binding.

Event grid trigger :-

init.py:-

import json
import logging

import azure.functions as func


def main(event: func.EventGridEvent):
    result = json.dumps({
        'id': event.id,
        'data': event.get_json(),
        'topic': event.topic,
        'subject': event.subject,
        'event_type': event.event_type,
    })

    logging.info('Python EventGrid trigger processed an event: %s', result)

function.json:-

{
  "scriptFile": "__init__.py",
  "bindings": [
    {
      "type": "eventGridTrigger",
      "name": "event",
      "direction": "in"
    }
  ]
}

Function V2 code:-

app.py:-

import logging
import azure.functions as func

app = func.FunctionApp()

@app.event_grid_trigger(arg_name="azeventgrid")
def EventGridTrigger(azeventgrid: func.EventGridEvent):
    logging.info('Python EventGrid trigger processed an event')

There's no direct way to limit the Defender warning, As a workaround you can Create an Alert rule to Supress the Function warning like below:-

Reference