I have a running Rancher cluster v2.1.6 that I would like to upgrade. I have full admin privileges to the cluster via Rancher frontend including access to the ‘local’ cluster. However the original installation was not done by me and I no longer have access to the original kubeconfig from RKE. I have doubts that the kubeconfig that I download from the web interface would work during the upgrade while Rancher itself would be going up and down.
So I wonder if it is possible to recover the kubeconfig with kube-admin user and certificate-based auth that could talk to kubeapi on port 6443 from the cluster, or should I just proceed with the one that I get from Rancher UI for the upgrade?