upgrade kubernetes cluster with kubeadm
1. upgrade control plane
apt update
apt-cache madison kubeadm
kubectl drain controlplane
kubeadm upgrade plan
--- compare the highest version available with the output of this command:
apt-cache madison kubeadm
--- install the highest version:
apt-get upgrade -y kubeadm=1.19.4-00
kubeadm upgrade apply v1.19.4
apt-get install -y kubelet=1.19.4-00 kubectl=1.19.4-00
kubectl uncordon controlplane
--- upgrade node01:
kubectl drain node01
ssh node01
apt update
apt-cache madison kubeadm
apt-get upgrade -y kubeadm=1.19.3-00
apt-get install -y kubelet=1.19.3-00
logout
kubectl uncordon node01