Azure Functions Logging - Log info at module level - python-3.x

Question

I'm trying to log info to Application Insights at the module level of code as oppsosed to the function level.
I can successfully log INFO, WARNING etc when the logger is called from within a function (in any module of my project), but not when called outside a function, (eg initializing a module, want to log some settings)
For example, when running my HttpTrigger app in azure functions, this works, and logs info to app insights:
import logging
def main(req: func.HttpRequest) -> func.HttpResponse:
logging.info('this message is logged successfully')
do_something()
while this does not work:
import logging
logging.info('this message isnt logged anywhere')
def main(req: func.HttpRequest) -> func.HttpResponse:
do_something()
I've tried using named loggers, changing logging settings eg:
import logging
log = logging.getLogger(__name__)
log.setLevel(logging.INFO)
log.info('This still isnt logged')
def main(req: func.HttpRequest) -> func.HttpResponse:
do_something()
and changing config in host.json:
{
"version": "2.0",
"extensionBundle": {
"id": "Microsoft.Azure.Functions.ExtensionBundle",
"version": "[1.*, 2.0.0)"
},
"logging": {
"fileLoggingMode": "always",
"logLevel": {
"default": "Information",
"Host.Results": "Information",
"Function": "Information",
"Host.Aggregator": "Information"
}
}
}
When running code locally, info is printed to stdout correctly everywhere.
I assume I must be misunderstanding exactlty how logging works in az. If anyone can fill in my gaps here for why the logging isn't working as I expect that would be appreciated!

Answer 1

This is the cause:
Problem comes from the app logging is not open by default on azure. This is the solution:
Go to Platform features -> All Settings.
Go to search app service logs -> app logging -> set time for saving log -> save the edit.
Then everything will be ok.
This is my code:
import logging
import azure.functions as func
logger = logging.getLogger('name')
logger.setLevel(logging.DEBUG)
sh = logging.StreamHandler()
sh.setLevel(logging.INFO)
logger.addHandler(sh)
logger.info('This will work.')
def main(req: func.HttpRequest) -> func.HttpResponse:
logging.info('Python HTTP trigger function processed a request.')
name = req.params.get('name')
if not name:
try:
req_body = req.get_json()
except ValueError:
pass
else:
name = req_body.get('name')
if name:
return func.HttpResponse(f"Hello {name}!")
else:
return func.HttpResponse(
"Please pass a name on the query string or in the request body",
status_code=400
)
Before setting, I face the same problem as yours. But after setting, I can get the INFO:
This is the offcial doc:
https://learn.microsoft.com/en-us/azure/app-service/troubleshoot-diagnostic-logs#enable-application-logging-linuxcontainer