TokenRefresher error handling

[phillebaba]

Which version of the SDK was used?

v0.14.0

Which platform are you using? (ex: Windows, Linux, Debian)

Linux

What problem was encountered?

Currently the TokenRefresher function passed when creating a NewToken does not have a clear method of dealing with errors when a token refresh fails.

azure-storage-blob-go/azblob/zc_credential_token.go

Line 34 in da33351

func NewTokenCredential(initialToken string, tokenRefresher TokenRefresher) TokenCredential {

Some documentation recommends returning a 0 to stop the token refresh all together, but this is not really an optimal solution. I have seen scenarios where Azure API rate limits have been reached where it would be better to just retry later in an attempt to wait it out. Either way I feel like there should be a better solution to the token refresh logic.

The point of creating this issue is to start a discussion about a better solution, or understand why the way it is done today is the most optimal solution.

How can we reproduce the problem in the simplest way?

N/A

Have you found a mitigation/solution?

N/A

[MaurGi]

I agree with this - returning 0 is not a good option, eventually the token will expire and no one will evel refresh it again - so retrying is a good idea - but it should be retrying only for a limited time, then panic/bail because it cannot be refreshed