Azure Function not picking up Eventhub events

Question

I started playing around with Azure Functions and am running in the issue that my Function is not being triggered by events entering my eventhub.

This is the code for my Function:

host.json:

  "version": "2.0",
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": true,
        "excludedTypes": "Request"
      }
    }
  },
  "extensionBundle": {
    "id": "Microsoft.Azure.Functions.ExtensionBundle",
    "version": "[2.*, 3.0.0)"
  }
}

function.json:

  "scriptFile": "__init__.py",
  "bindings": [
    {
      "type": "eventHubTrigger",
      "name": "events",
      "direction": "in",
      "eventHubName": "eventhub",
      "connection": "eventhub_connection",
      "cardinality": "many",
      "consumerGroup": "$Default",
      "dataType": "stream"
    }
  ]
}

init.py:

import logging

import azure.functions as func


def main(events: List[func.EventHubEvent]):
    for event in events:
        logging.info('Python EventHub trigger processed an event: %s',
                        event.get_body().decode('utf-8'))
        logging.info(f'Function triggered to process a message: {event.get_body().decode()}')
        logging.info(f'  EnqueuedTimeUtc = {event.enqueued_time}')
        logging.info(f'  SequenceNumber = {event.sequence_number}')
        logging.info(f'  Offset = {event.offset}')

# def main(event: func.EventHubEvent):
#     logging.info(f'Function triggered to process a message: {event.get_body().decode()}')
#     logging.info(f'  EnqueuedTimeUtc = {event.enqueued_time}')
#     logging.info(f'  SequenceNumber = {event.sequence_number}')
#     logging.info(f'  Offset = {event.offset}')

#     # Metadata
#     for key in event.metadata:
#         logging.info(f'Metadata: {key} = {event.metadata[key]}')

  "IsEncrypted": false,
  "Values": {
    "FUNCTIONS_WORKER_RUNTIME": "python",
    "AzureWebJobsStorage": "DefaultEndpointsProtocol=https;AccountName=storageaccount;AccountKey=storageacciuntaccesskey=;EndpointSuffix=core.windows.net",
    "eventhub_connection": "Endpoint=sb://eventhub01.servicebus.windows.net/;SharedAccessKeyName=function;SharedAccessKey=0omitted;EntityPath=eventhub"
  }
}

I started out with the basic eventhub python code provided by the Azure Function Core tools. And have been testing different pieces of code found in online examples from people's blogs and the Microsoft docs.

When switching to cardinality: one -> I switch to the code which is currently commented out. I don't know if that is supposed to go like that, it just feels right to me.

In any case, regardless of the cardinality setting, or the datatype being changed between binary, stream or string. My Function simply does not trigger.

I can query my eventhub and see/read the events. So I know my policy, and the sharedkey and such, work fine. I am also only using the $Default consumer group.

I also tried setting up a HTTP triggered function, and this function gets triggered from Azure Monitor. I can see in the logs each request entering the function.

Am I doing something wrong in the code for my eventhub function? Am I missing some other configuration setting perhaps? I already checked the Access Rules on the function, but that realy doesn't matter does it? The function is pulling the event from the eventhub. It's not being sent data by an initiator.

Edit: Added the local.settings.json file configuration and updated the function.json Edit 2: solution to my specific issue is in the comments of the answer.

Cindy Pau Cindy Pau · Accepted Answer · 2021-04-26T01:39:31

Update:

__init__.py of the function:

from typing import List
import logging

import azure.functions as func


def main(events: List[func.EventHubEvent]):
    for event in events:
        logging.info('Python EventHub trigger processed an event: %s',
                        event.get_body().decode('utf-8'))

Send message to event hub:

import asyncio
from azure.eventhub.aio import EventHubProducerClient
from azure.eventhub import EventData

async def run():
    # Create a producer client to send messages to the event hub.
    # Specify a connection string to your event hubs namespace and
    # the event hub name.
    producer = EventHubProducerClient.from_connection_string(conn_str="Endpoint=sb://testbowman.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=xxxxxx;EntityPath=test", eventhub_name="test")
    async with producer:
        # Create a batch.
        event_data_batch = await producer.create_batch()

        # Add events to the batch.
        event_data_batch.add(EventData('First event '))
        event_data_batch.add(EventData('Second event'))
        event_data_batch.add(EventData('Third event'))

        # Send the batch of events to the event hub.
        await producer.send_batch(event_data_batch)

loop = asyncio.get_event_loop()
loop.run_until_complete(run())

And please make sure you give the right event hub name:

It seems your function.json has a problem, the connection string should not directly put in the binding item.

It should be like below:

function.json

{
  "scriptFile": "__init__.py",
  "bindings": [
    {
      "type": "eventHubTrigger",
      "name": "events",
      "direction": "in",
      "eventHubName": "test",
      "connection": "testbowman_RootManageSharedAccessKey_EVENTHUB",
      "cardinality": "many",
      "consumerGroup": "$Default",
      "dataType": "binary"
    }
  ]
}

local.settings.json

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "DefaultEndpointsProtocol=https;AccountName=0730bowmanwindow;AccountKey=xxxxxx;EndpointSuffix=core.windows.net",
    "FUNCTIONS_WORKER_RUNTIME": "python",
    "testbowman_RootManageSharedAccessKey_EVENTHUB": "Endpoint=sb://testbowman.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=xxxxxx;EntityPath=test"
  }
}

Azure Function not picking up Eventhub events

1 Answers