ADC support for impersonated credentials failing with 401 - Reason CREDENTIALS_MISSING

[randypuro]

The actual request, after generating an auth token, is missing the auth headers. The code tries to prepare the auth header using the source credentials, presuming the passed in hash will be mutated.

However, source_credentials subclassing from BaseClient will return a modified copy of the passed in hash rather than mutating the passed in hash.

[varunlalan]

I'm seeing the same 401 error. Any quick fix for this?

[randypuro]

I've just monkeypatched ImpersonatedServiceAccountCredentials to fix the method:

module Google
  module Auth
    class ImpersonatedServiceAccountCredentials
      private

      def prepare_auth_header
        @source_credentials.updater_proc.call({})
      end
    end
  end
end