AppEngineCredential depends on legacy bundled service

[yonghaoy]

Hello, we are upgrading GAE from Java 8 to 11 and also trying to get ride of legacy bundled service .

Here is how we generate default AccessToken today.

GoogleCredentials credentials = AppEngineCredentials.newBuilder().setScopes(scopes).setAppIdentityService(AppIdentityServiceFactory.getAppIdentityService()).build();

The reason we do it this way is because if using GoogleCredentials.getDefaulCredential, because the call to .createScoped will silently proceed by doing nothing?

Question:
1: How to use AppEngineCredentials without turning on legacy bundle? Because I get feature not enabled error when calling without turning it on
2: Do we still need to include appengine-sdk1.0 in our dependency? As those imports are there:

import com.google.appengine.api.appidentity.AppIdentityService;
import com.google.appengine.api.appidentity.AppIdentityService.GetAccessTokenResult;
import com.google.appengine.api.appidentity.AppIdentityServiceFactory;

Thanks

[yonghaoy]

And why GoogleCredentials.getDefaulCredential does not work, I suspect it's related with
#1274

[arithmetic1728]

I guess you meant GoogleCredentials.getApplicationDefault method.

From the code, it looks like createScoped should work with GoogleCredentials.getApplicationDefault, if it returns an app engine credentials.

The getApplicationDefault code to get app engine cred:
https://github.com/googleapis/google-auth-library-java/blob/main/oauth2_http/java/com/google/auth/oauth2/DefaultCredentialsProvider.java#L197-L199

App engine code to add scopes:
https://github.com/googleapis/google-auth-library-java/blob/main/appengine/java/com/google/auth/appengine/AppEngineCredentials.java#L94

For the Java specific question, I will leave it to our Java expert.

[yonghaoy]

createScoped does not work after upgrading from 1.11 to 1.24. I suspect that is similar to #1274...

For now, we have to bring back legacy service and use the old way to get a token that with scopes.
https://github.com/all-of-us/workbench/blob/727be385a0c5b3895ddf8650c4900aef4875a278/api/src/main/java/org/pmiops/workbench/auth/ServiceAccounts.java#L39L53

[yonghaoy]

Also for the code you pointed above: https://github.com/googleapis/google-auth-library-java/blob/main/oauth2_http/java/com/google/auth/oauth2/DefaultCredentialsProvider.java#L197-L199
seems it only works for GAE 7 standard env? Is that right?