Develop Reference

Can't add more than one item to Azure Queue in function app

I have a TimerTrigger function that runs every couple minutes and adds multiple items to a queue, which a QueueTrigger function should process. But each time the QueueTrigger function is firing only once.
my TimerTrigger function:
def main(mytimer: func.TimerRequest, msg: func.Out[str]) -> None:
utc_timestamp = datetime.datetime.utcnow().replace(
tzinfo=datetime.timezone.utc).isoformat()
if mytimer.past_due:
logging.info('The timer is past due!')
logging.info('Python timer trigger function ran at %s', utc_timestamp)
msg.set("1")
msg.set("2")
QueueTrigger function:
def main(msg: func.QueueMessage) -> None:
logging.info('Python queue trigger function processed a queue item: %s',
msg.get_body().decode('utf-8'))
function.json of the TimerTrigger:
{
"scriptFile": "__init__.py",
"bindings": [
{
"name": "mytimer",
"type": "timerTrigger",
"direction": "in",
"schedule": "0 */2 * * * *"
},
{
"name": "msg",
"type": "queue",
"direction": "out",
"queueName": "js-queue-items",
"connection": "AzureWebJobsStorage"
}
]
}
function.json of the QueueTrigger:
{
"scriptFile": "__init__.py",
"bindings": [
{
"name": "msg",
"type": "queueTrigger",
"direction": "in",
"queueName": "js-queue-items",
"connection": "AzureWebJobsStorage"
}
]
}
local.settings.json:
{
"IsEncrypted": false,
"Values": {
"AzureWebJobsStorage": "UseDevelopmentStorage=true",
"FUNCTIONS_WORKER_RUNTIME": "python"
}
}
How can I fix this?

There is no intrinsic way of connecting to the queue storage using azure time trigger i.e. the queue storage will treat the time trigger as any other console application or any other piece of program which is trying to connect to the storage and add message.
Thus, we have to add the messages the classical way by using connection strings.
connectionstring = ""
queuename = ""
messages = ""
queueClient = QueueClient.from_connection_string(connectionString, queueName)
queueClient.send_message(message)
Thus, when queue trigger will start only once during the start and remain idle because no messages are added and thus it will not be triggered.
Refer the documentation on timetrigger and queuetrigger and how to add message to queue using python.

Create Azure TimerTrigger Durable Function in python

As I claimed in the title, is possible to have an azure durable app that triggers using TimerTrigger and not only httpTrigger?
I see here https://learn.microsoft.com/en-us/azure/azure-functions/durable/quickstart-python-vscode a very good example on how implement it with HttpTrigger Client and I'd like to have an example in python on how do it with a TimerTrigger Client, if it's possible.
Any help is appreciate, thanks in advance.

Just focus on the start function is ok:
__init__py
import logging
import azure.functions as func
import azure.durable_functions as df
async def main(mytimer: func.TimerRequest, starter: str) -> None:
client = df.DurableOrchestrationClient(starter)
instance_id = await client.start_new("YourOrchestratorName", None, None)
logging.info(f"Started orchestration with ID = '{instance_id}'.")
function.json
{
"scriptFile": "__init__.py",
"bindings": [
{
"name": "mytimer",
"type": "timerTrigger",
"direction": "in",
"schedule": "* * * * * *"
},
{
"name": "starter",
"type": "orchestrationClient",
"direction": "in"
}
]
}

Trying to trigger an url from azure functions using python, errored saying "without a $return binding returned a non-None value"

Below is the code,
import logging
import json
import urllib.request
import urllib.parse
import azure.functions as func
def main(myblob: func.InputStream):
logging.info(f"Python blob trigger function processed blob \n"
f"Name: {myblob.name}\n"
f"Blob Size: {myblob.length} bytes")
response = urllib.request.urlopen("http://example.com:5000/processing")
return {
'statusCode': 200,
'body': json.dumps(response.read().decode('utf-8'))
}
Error: Result: Failure Exception: RuntimeError: function 'abc' without a $return binding returned a non-None value Stack: File "/azure-functions-host/workers/python/3.7/LINUX/X64/azure_functions_worker/dispatcher.py", line 341, in _handle__invocation_request f'function {fi.name!r} without a $return binding '. The same code works in lambda.. Please help me in debugging in azure functions.
function.json
{
"scriptFile": "__init__.py",
"bindings": [
{
"name": "myblob",
"type": "blobTrigger",
"direction": "in",
"path": "sourcemetadata/{name}",
"connection": "AzureWebJobsStorage"
}
]
}

In the Azure function, if you use return in the function app code, it means that you want to use output binding. But you do not define it in function.json. Please define it. For more details, please refer to here and here
For example
I use process blob with blob trigger and send message to azure queue with queue output binding
function.json
{
"scriptFile": "__init__.py",
"bindings": [
{
"name": "myblob",
"type": "blobTrigger",
"direction": "in",
"path": "test/{name}.csv",
"connection": "AzureWebJobsStorage"
},
{
"name": "$return",
"direction": "out",
"type": "queue",
"queueName": "outqueue",
"connection": "AzureWebJobsStorage"
}
]
}
Code
async def main(myblob: func.InputStream) :
logging.info(f"Python blob trigger function processed blob \n"
f"Name: {myblob.name}\n")
return "OK"

Azure Functions (Python) blob ouput binding. How to set name when name is only part of the input message

I have an Azure Functions (Python 3) function that takes a message from a Service Bus queue and creates a Blob in a container as a result.
The function trigger is the Sevice Bus message. This message is a JSON object with several properties, one of which is the blob name.
The docs suggest something like this in the bindings:
{
"name": "outputblob",
"type": "blob",
"path": "samples-workitems/{queueTrigger}-Copy",
"connection": "MyStorageConnectionAppSetting",
"direction": "out"
}
But this suggest that the triggering message contains just the blob name. I can not make the message solely the blob name as I require the other attributes in the message to determine what to do / what data to put in the blob.
Is there any way to use the output bindings that will resolve this for me?
Thanks.

Yes, this could be done. You could just set the input and output binding path with the json value from the trigger json data. The below is my function.json. Use service bus trigger get the input blob name and output blob name, then write the input blob to the output blob. You could also set the container name with this way.
{
"scriptFile": "__init__.py",
"bindings": [
{
"name": "msg",
"type": "serviceBusTrigger",
"direction": "in",
"queueName": "myqueue",
"connection": "servicebuscon"
},
{
"name": "inputblob",
"type": "blob",
"path": "inputcontainer/{blobname}",
"connection": "AzureWebJobsStorage",
"direction": "in"
},
{
"name": "outputblob",
"type": "blob",
"path": "outputcontainer/{outblobname}",
"connection": "AzureWebJobsStorage",
"direction": "out"
}
]
}
And the below is the function code.
import logging
import azure.functions as func
import json, os
def main(msg: func.ServiceBusMessage,inputblob: func.InputStream,outputblob: func.Out[bytes]) -> func.InputStream:
logging.info('Python ServiceBus queue trigger processed message: %s',
msg.get_body().decode('utf-8'))
jsonData= json.loads(inputblob.read())
logging.info(jsonData)
outputblob.set(str(jsonData))
And I set the service bus message like below message.
Here is the result pic. You could find the input blob json data shown in the console and I check the container the output blob is created.

How Do I get the Name of The inputBlob That Triggered My Azure Function With Python

I have an azure function which is triggered by a file being put into blob storage and I was wondering how (if possible) to get the name of the blob (file) which triggered the function, I have tried doing:
fileObject=os.environ['inputBlob']
message = "Python script processed input blob'{0}'".format(fileObject.fileName)
and
fileObject=os.environ['inputBlob']
message = "Python script processed input blob'{0}'".format(fileObject.name)
but neither of these worked, they both resulted in errors. Can I get some help with this or some suggesstions?
Thanks

The blob name can be captured via the Function.json and provided as binding data. See the {filename} token below.
Function.json is language agnostic and works in all languages.
See documentation at https://learn.microsoft.com/en-us/azure/azure-functions/functions-triggers-bindings for details.
{
"bindings": [
{
"name": "image",
"type": "blobTrigger",
"path": "sample-images/{filename}",
"direction": "in",
"connection": "MyStorageConnection"
},
{
"name": "imageSmall",
"type": "blob",
"path": "sample-images-sm/{filename}",
"direction": "out",
"connection": "MyStorageConnection"
}
],
}

If you want to get the file name of the file that triggered your function you can to that:
Use {name} in function.json :
{
"bindings": [
{
"name": "myblob",
"type": "blobTrigger",
"path": "MyBlobPath/{name}",
"direction": "in",
"connection": "MyStorageConnection"
}
]
}
The function will be triggered by changes in yout blob storage.
Get the name of the file that triggered the function in python (init.py):
def main(myblob: func.InputStream):
filemane = {myblob.name}
Will give you the name of the file that triggered your function.

There is not any information about what trigger you used in your description. But fortunately， there is a sample project yokawasa/azure-functions-python-samples on GitHub for Azure Function using Python which includes many samples using different triggers like queue trigger or blob trigger. I think it's very helpful for you now, and you can refer to these samples to write your own one to satisfy your needs。
Hope it helps.

Getting the name of the inputBlob is not currently possible with Python Azure-Functions. There are open issues about it in azure-webjobs-sdk and azure-webjobs-sdk-script GitHub:
https://github.com/Azure/azure-webjobs-sdk/issues/1090
https://github.com/Azure/azure-webjobs-sdk-script/issues/1339

Unfortunatelly it's still not possible.
In Python, you can do:
import azure.functions as func
import os
def main(blobin: func.InputStream):
filename=os.path.basename(blobin.name)