When I have created a cluster with some nodes on GKE, which user does Google interpret my requests as coming from? E.g. if I open a console on one of the nodes and do an API call to the Stackdriver API. Which user does the API think I am?

$ kubectl exec -it my-app bash
$ rails c
irb(main):005:0* Google::Cloud::ErrorReporting.report \
                 Exception.new(msg: "from console")
=> nil
irb(main):006:0> {:msg=>"from console"} (Exception)
Google::Cloud::PermissionDeniedError: 7:User not authorized.

I thought I was Compute Engine default service account, but that can't be right? I gave that service account the Owner role to test and it still fails.

Do I need to install gcloud on my Docker images on GKE so that I can authenticate as an service account with the correct roles before I start rails?