upgrading-kubeadm-cluster-from-v1.13.0-to-v1.13.5.md

upgrade-kubeadm-cluster

The way to upgrade K8S cluster created with kubeadm from version 1.13.0 to 1.13.5

1. Find the version to upgrade to

sudo apt update
sudo apt-cache policy kubeadm

2. Upgrade the control plane (master) node

sudo apt-mark unhold kubeadm
sudo apt update && sudo apt upgrade
sudo apt-get install kubeadm=1.13.5-00
sudo apt-mark hold kubeadm

Verify that the download works and has the expected version:

sudo kubeadm version

Apply the upgrade by executing the following command:

sudo kubeadm upgrade apply v1.13.5

3. Upgrade the kubelet and kubectl on the control plane (master) node

sudo apt-mark unhold kubelet
sudo apt update && sudo apt upgrade
sudo apt-get install kubelet=1.13.5-00 kubectl=1.13.5-00

Restart the kubelet

sudo systemctl restart kubelet

4. Upgrade worker nodes

Upgrade kubeadm on all worker nodes:

sudo apt-mark unhold kubeadm
sudo apt update && sudo apt upgrade
sudo apt-get install kubeadm=1.13.5-00
sudo apt-mark hold kubeadm

Cordon the node, on the Master node, run:

sudo kubectl drain $NODE --ignore-daemonsets

Output:

node/worker-node cordoned
WARNING: ignoring DaemonSet-managed Pods: kube-system/kube-flannel-ds-amd64-s8j5k, kube-system/kube-proxy-whc6q
evicting pod "coredns-fb8b8dccf-jhlgr"
evicting pod "test-ru-jz5df"
pod/coredns-fb8b8dccf-jhlgr evicted
pod/test-ru-jz5df evicted
node/worker-node evicted

Upgrade the kubelet config on worker node

sudo kubeadm upgrade node config --kubelet-version v1.13.5

Upgrade kubelet and kubectl

sudo apt update && sudo apt upgrade
sudo apt-get install kubelet=1.13.5-00 kubectl=1.13.5-00

Restart the kubelet

sudo systemctl restart kubelet

Uncordon the node, bring the node back online by marking it scheduable

sudo kubectl uncordon $NODE

Verify the status of the cluser

sudo kubectl get nodes

The result:

NAME          STATUS   ROLES    AGE    VERSION
cncf          Ready    master   172m   v1.13.5
worker-node   Ready    <none>   169m   v1.13.5