MI doesn't work for environments that don't have a shell

[keegan-caruso]

Microsoft.Identity.Web Library

Microsoft.Identity.Web.Certificate

Microsoft.Identity.Web version

latest

Web app

Not Applicable

Web API

Not Applicable

Token cache serialization

Not Applicable

Description

See here: https://github.com/AzureAD/microsoft-identity-web/blob/master/src/Microsoft.Identity.Web.Certificate/KeyVaultCertificateLoader.cs#L49-L53

Azure.Identity will fault if it cannot open a shell, distroless containers will not have a shell so they are guaranteed to fault.

There are options here: https://learn.microsoft.com/en-us/dotnet/api/azure.identity.defaultazurecredentialoptions?view=azure-dotnet

That allow excluding flows from the authentication chain.

The ability to supply my own or modify the options should work.

Reproduction steps

Use MI on a container build from a distroless image.

Error message

AzureCliCredential authentication failed: An error occurred trying to start process '/bin/sh' with working directory '/bin/'. No such file or directory

Id Web logs

No response

Relevant code snippets

NA

Regression

No response

Expected behavior

Able to use MI in distroless containers.

[jmprieur]

You need to set the environment variable AZURE_EXCLUDE_AZURE_CLI_CREDENTIAL to true

This will prevent the DefaultAzureCredential from using the Azure CLI credential provider. You can also use other environment variables to exclude other credential types, such as AZURE_EXCLUDE_INTERACTIVE_BROWSER_CREDENTIAL, or VS, VS Code, etc ..

[joerattazzi-microsoft]

Thanks for the response, @jmprieur .

I've tried setting that environment variable in our helm chart. I can see this set on the environment variables list, but same failure occurs:

 - name: AZURE_EXCLUDE_AZURE_CLI_CREDENTIAL
   value: 'true'

Can you confirm this is the right Environment Variable to set, please? Thanks!

[joerattazzi-microsoft]

@jmprieur - any chance you can weigh in on this?

[joerattazzi-microsoft]

@jmprieur - bump

[jmprieur]

I think this was fixed in the latest version.
Do you mind to check?

[jmprieur]

@keegan-caruso. I believe this is done?

[keegan-caruso]

Working through previews with a partner. Not on main yet.