Upgrading.md

Upgrading your Kubernetes Cluster

Kubernetes versions take the format Major.Minor.Patch (1.27.8)

1. Read the CHANGELOG file! Seriously
2. Upgrade each control plane node fully before moving to the next
   1. Upgrade kubeadm

      #Change the kubernetes version in /etc/apt/sources.list.d/kubernetes.list
      apt-mark unhold kubeadm
      apt-get update
      apt-get upgrade -y kubeadm
      apt-mark hold kubeadm
      

   2. Upgrade node with kubeadm
      1. On first control plan node upgrade only

         kubeadm upgrade plan v1.28.10
         kubeadm upgrade apply v1.28.10
         

      2. On other control plan nodes only

         kubeadm upgrade node
         

   3. Upgrade kubelet and kubectl

      kubectl drain <node-to-drain> --ignore-daemonsets
      apt-mark unhold kubelet kubectl
      apt-get update
      apt-get upgrade -y kubelet kubectl
      apt-mark hold kubelet kubectl
      

   4. Restart kubelet service

      systemctl daemon-reload
      systemctl restart kubelet
      

   5. Upgrade Containerd

      apt-mark unhold containerd.io
      apt upgrade containerd.io
      apt-mark hold containerd.io
      

   6. Uncordon the node

      kubectl uncordon <node-to-drain>
      

3. Upgrade each worker node fully before moving to the next
   1. Upgrade kubeadm

      #Change the kubernetes version in /etc/apt/sources.list.d/kubernetes.list
      apt-mark unhold kubeadm
      apt-get update
      apt-get upgrade -y kubeadm
      apt-mark hold kubeadm
      

   2. Upgrade node with kubeadm

      kubeadm upgrade node
      

   3. Upgrade kubelet and kubectl

      kubectl drain <node-to-drain> --ignore-daemonsets --delete-emptydir-data
      apt-mark unhold kubelet kubectl
      apt-get update
      apt-get upgrade -y kubelet kubectl
      apt-mark hold kubelet kubectl
      

   4. Restart kubelet service

      systemctl daemon-reload
      systemctl restart kubelet
      

   5. Upgrade Containerd

      apt-mark unhold containerd.io
      apt upgrade containerd.io
      apt-mark hold containerd.io
      

   6. Uncordon the node

      kubectl uncordon <node-to-drain>