Create documentation that describes how to troubleshoot and fix `'0 functions loaded'`

[Francisco-Gamino]

We do not have any public documentation that describes how to troubleshoot and fix this issue.

Below is an answer on how to fix this issue from ChatGPT. Could you please verify this information and add anything that might be missing? Also, if the troubleshooting instructions are different for the V1 and V2 programming models, please create a section for each.

ChatGPT Answer: If you're encountering the "0 functions loaded" issue for your .NET Azure Function, it means that the Azure Functions runtime was unable to discover and load any functions within your project. This issue can have several causes, and I'll outline some steps to troubleshoot and resolve it:

If you're encountering the "0 functions loaded" issue for your Python Azure Function, it means that the Azure Functions runtime was unable to discover and load any functions within your project. This issue can have several causes, and I'll outline some steps to troubleshoot and resolve it:

1. Check Your Function Code:

   • Ensure that you have one or more functions defined in your Python project. Functions should be defined as regular Python functions with appropriate decorators (e.g., @func_name) to identify them as Azure Functions.

2. Function Names and Decorators:

   • Confirm that your function names match the names specified in decorators like @func_name. These names should be unique and correspond to the function you want to trigger.

3. Function Project Structure:

   • Verify that your project has the correct structure for Azure Functions. It should include a folder structure that follows the convention (e.g., MyFunctionProject/function_name/__init__.py).

4. Function Configuration:

   • Check your local.settings.json or application settings for any configuration issues that might prevent the Azure Functions runtime from initializing correctly.

5. Python Version:

   • Ensure that you're using a supported version of Python for Azure Functions. As of my last knowledge update in September 2021, Azure Functions supported Python 3.6, 3.7, and 3.8. Check the Azure Functions documentation for updates on supported Python versions.

6. Function Host Version:

   • Make sure you have the appropriate version of the Azure Functions host installed. The host version should be compatible with your project. Use the Azure Functions Core Tools to update or check the host version.

7. Logs and Errors:

   • Check the Azure Functions runtime logs for any error messages or warnings that might provide clues about why functions are not loading.

8. Dependencies:

   • Ensure that you have correctly installed any required dependencies or libraries in your Python environment. Use a virtual environment to manage dependencies if needed.

9. Function Signature and Parameters:

   • Check that the function signatures and parameters match the expected format for Azure Functions. Functions should accept an input parameter and may return a response.

10. Extension Bundle:

    • Azure Functions for Python may require an extension bundle to include additional dependencies. Make sure you have the correct extension bundle installed for your Python version and Azure Functions runtime. Refer to Azure Functions documentation for Python for details.

11. Azure Function Hosting Plan:

    • Check that your Azure Function App hosting plan is correctly configured and that you are deploying to the correct plan.

12. Update Azure Functions Runtime:

    • Ensure that you have the latest version of the Azure Functions runtime installed on your Azure hosting environment if you're deploying there.

[levalencia]

I wonder when can we have official documentation for this, very annoying bug.

[sudharsan2020]

@Francisco-Gamino We generally encounter this issue post docker deployment and follow the below steps to troubleshoot and fix. https://github.com/Azure/azure-functions-docker/issues/987#issuecomment-1846724440