I am new to k8s and I wonder what is the difference in terms of rbac between service account with role of cluster-admin in kube-system namespace and service account with role of cluster-admin in any other namespace. Thanks
cluster-admin is a ClusterRole. If you use a RoleBinding, it will apply to only the namespace that RoleBinding is in. If you use a ClusterRoleBinding it will apply to all namespaces.