Unlike normal users, service account is used by processes inside a pod to contact the Kubernetes API server. By default, a Kubernetes cluster creates different service accounts for different purposes. In GKE, there are bunch of service accounts that have been created:
// list service account across all namespaces # kubectl get serviceaccount --all-namespaces NAMESPACE NAME SECRETS AGE default default 1 5d kube-public default 1 5d kube-system namespace-controller 1 5d kube-system resourcequota-controller 1 5d kube-system service-account-controller 1 5d kube-system service-controller 1 5d project1 default 1 2h ...
Kubernetes will create a default service account in each...