kubernetes: Error from server (Forbidden): User "system:anonymous" cannot list nodes at the cluster scope even after granting permission

Your problem is not with your ClusterRoleBindings but rather with user authentication. Kubernetes tells you that it identified you as system:anonymous (which is similar to *NIX's nobody) and not nsp@example.com (to which you applied your binding).

In your specific case the reason for that is that the username flag uses HTTP Basic authentication and needs the password flag to actually do anything. But even if you did supply the password, you'd still need to actually tell the API server to accept that specific user.

Have a look at this part of the Kubernetes documentation which deals with different methods of authentication. For the username and password authentication to work, you'd want to look at the Static Password File section, but I would actually recommend you go with X509 Client Certs since they are more secure and are operationally much simpler (no secrets on the Server, no state to replicate between API servers).

In my case i was receiving nearly similar error due to RBAC

Error

root@k8master:~# kubectl cluster-info dump --insecure-skip-tls-verify=trueError from server (Forbidden): nodes is forbidden: User "system:anonymous" cannot list resource "nodes" in API group "" at the cluster scope

Solution:As Solution i have done below things to reconfigure my user to access cluster

cd $HOMEsudo whoamisudo cp /etc/kubernetes/admin.conf $HOME/sudo chown $(id -u):$(id -g) $HOME/admin.confexport KUBECONFIG=$HOME/admin.confecho "export KUBECONFIG=$HOME/admin.conf" | tee -a ~/.bashrc

After doing above when i take cluster dump i got result

root@k8master:~# kubectl cluster-infoKubernetes master is running at https://192.168.10.15:6443KubeDNS is running at https://192.168.10.15:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy