Logging DEBUG logs are not shown when executing the Python Azure Functions

Question

I have created a Python Azure Functions app. In this application I want to check log details like DEBUG, INFO etc. I have written some code for logging purpose, but I am not able to get any log after executing my azure function application.

I have written basic code for logging purpose as below but after executing Azure Functions I am not able to see the log on console.

    import logging
    import azure.functions as func

    data = "Hello"
    logging.basicConfig(level=logging.DEBUG)
    logging.debug(data)

Is there any other solution or workaround for the above problem?

Answer 1

Most likely the root logger got messed with by azure and basicConfig only creates a root logger with some sane defaults. To work around this create your own independent logger.

import logging

logger = logging.getLogger('akshay')
logger.setLevel(logging.DEBUG)
sh = logging.StreamHandler()
sh.setLevel(logging.DEBUG)
logger.addHandler(sh)
logger.debug('Hello')
# Outputs 'Hello'

Answer 2

This GitHub issue explains the solution:

As for the original issue noted here, the desired behavior can be achieved with a combination of two steps:

1. Setting the root logger in user code to use the debug level (it is set to to info by default).
2. Configuring the host.json to log Debug messages: [...]

Specifically, this is the code that you need in your script:

import logging
logging.Logger.root.level = 10
logging.debug("Debug message here")