ComputeEngineCredentials equivalent in unified credentials

[lordgamez]

Hi Team,

In the Apache MiNiFi C++ project we are currently using the gcs::oauth2::Credentials. I see in the latest codebase that these credentials are deprecated in favor of the new unified credentials. Most of the use cases supported in MiNiFi can be ported to the new credentials format, but gcs::oauth2::ComputeEngineCredentials doesn't seem to have an equivalent of in the unified credentials. I see that the google::cloud::MakeGoogleDefaultCredentials supports these credentials in the chain, but is there another option in the unified credentials to use the ComputeEngineCredentials explicitly?

[scotthart]

Thanks for pointing this out. We'll take a look.

[lordgamez]

Hi @scotthart! Do you have updates on the issue? Is this something that was missed and will be implemented later in the unified credentials, or this will not be supported separately and should only be used through the default credentials?

[scotthart]

We're going to add an explicit function google::cloud::MakeComputeEngineCredentials to provide parity with the functionality offered in gcs::oauth2::ComputeEngineCredentials.

[lordgamez]

Thank you @scotthart!

[scotthart]

Created #15673 to track.