[Bug] Azure ML MSI support is missing

[lenniehwtw-new]

Azure ML Studio uses similar environment variables to other hosting environments such as Azure App Service. In our previous implementation, we attempted to detect Azure App Service's environment variables before CloudShell. Because CloudShell uses a subset of the environment variables, it will be wrongly detected if it is attempted first in an AzureML environment and fails to add the value of the MSI_SECRET env var in a required header named secret.

See MSAL Python's implementation: https://github.com/AzureAD/microsoft-authentication-library-for-python/blob/dev/msal/managed_identity.py#L415

[rayluo]

@neha-bhargava , fyi, at one point the AzureML was believed to be only needed in Python, so we implemented in MSAL Python here and there. You can use that implementation as a reference, and help cross-check that implementation.

[neha-bhargava]

Azure SDK had implementation for App Service 2017, which read env variables MSI_ENDPOINT and MSI_SECRET. And the complete flow is same. So it worked with Azure SDK. In MSAL we skipped the implementation for App service 2017 as it was retired. We can add support for Azure ML, it is similar to App service just the env variables for endpoint and secret are different.

Thanks @rayluo for pointing out the code in MSAL Python.

Azure SDK implementation of App service 2017 can be found here

[lenniehwtw-new]

Is there any update on this?