Doubt in node upgrade (from LL-1 solution)

Kubernetes
#1

  1. why can’t we upgrade worker node as same a master by using kubectl upgrade plan?

  2. can you explain what is happening in the last two commands step as we’ve mentioned --kubelet-version=v1.19.0 in 2nd command but we are downloading kubelet in the 3rd command

  3. why cant i uncordon worker node in itself why do i need to do it from master ?

  4. “To minimize downtime, the deployment gold-nginx should be rescheduled on an alternate node before upgrading each node.” how are we taking care of this part of the 1st question in the solution.

On Worker Node:-

apt-get install kubeadm=1.19.0-00
kubeadm upgrade node --kubelet-version=v1.19.0
apt-get install kubelet=1.19.0-00

#2

Hello @ajey

  1. To upgrade the worker nodes, run

    kubectl drain node01 --ignore-daemonsets
    ssh node01
    node01$ apt install kubeadm=1.12.0-00
    node01$ apt install kubelet=1.12.0-00
    master$ kubeadm upgrade node config --kubelet-version $(kubelet --version | cut -d ’ ’ -f 2)
    master$ kubectl uncordon node01

2- --kubelet-version flag upgrade the kubelet config file according to version

Regarding kubeadm upgrade node command is the same as kubeadm upgrade apply on master node.

please check here Upgrading kubeadm clusters | Kubernetes