GKE native auth

[pokorny-martin]

Hi,
we'd like to use headlamp as a k8s dashboard in many of our cluster across multiple GCP projects.
To ease the authentication I thought it would be nice to use the google accounts we are already using to do the IAM and for connecting to the clusters (with the gke-gcloud-auth-plugin).
I couldn't find any specific docs for it, but by searching a found last years commit: headlamp - commit #97b35e98, which I followed, but I am still stuck with receiving 401s.
Did anyone manage to do anything like that? Have I missed anything?