Azure function: Encountered an error (InternalServerError) from host runtime

Question

Hello,

I need to forward logs from Azure Monitor to a syslog server for ingestion in our SIEM.

Microsoft's documentation points to this Azure Function to achieve that. However, I'm having issues to configure it.

When I try to connect the Event Hub in the Integration tab (point 5 of the readme in the above link), I get the following error:

Failed to update AzureMonitor2Syslog (myEventHubMessage): Encountered an error (InternalServerError) from host runtime.

Sadly this message is not helpful at all. When I check logs from both SCM and the Log Stream, nothing is logged, so I'm not sure if it's an error coming from the function or if it's something crashing on Azure's backend.

How can I debug this error?
I'm not familiar with Azure Functions, so I may have just missed something stupid.

Or maybe there is another option to achieve my goal? (I found nothing else after hours of searching, but on another hand it would be a bit weird that Azure doesn't have something builtin to forward logs to a syslog server, since it's pretty standard requirement).

Thanks !

Answer 1

@Zoddo Thanks for reaching out. Please make sure that you have defined all the application settings in your function app as mentioned here and verified the usage section as this could be one of the reason of 500 error when you have not defined all the setting correctly in your azure function app.

There could be multiple reasons for 500 errors and the suggestion would be to validate the Diagnose and solve problems on your function app to know more details on any issue with your function app and the action plan suggested if any.