FR: oci_pull support identity tokens

[thesayyn]

credHelper response with {"Username": "<token>"} should be handled differently.

See moby/moby#36926

[wingsofovnia]

Any updates? Is there any priority assigned to this issue or perhaps there are blockers?

[thesayyn]

No, PRs are welcome.

[BradHolmes]

This small change in authn.bzl coupled with a custom credential-helper got things working for me. Anything else needed?

     if response["Username"] == "<token>":
-        fail("Identity tokens are not supported at the moment. See: https://github.com/bazel-contrib/rules_oci/issues/129")
+        return {
+            "type": "pattern",
+            "pattern": "Bearer <password>",
+            "password": response["Secret"],
+        }

I don't really have a good idea about adding an example or test though.

[wingsofovnia]

Should be fixed by #626

[thesayyn]

Closing as fixed.