How I Upgraded A Production Grade Kubernetes Cluster From 1.23.17 To 1.24.17 using Kubeadm
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Kubernetes, image credit - thelinuxnotes
In this article, I will share my experience in upgrading a bare metal Production grade Kubernetes cluster from 1.23.17 -> 1.24.17 using Kubeadm. The process is quite straightforward, however, there are some gotchas I encountered and I have documented them here, which may be helpful to you.
The process is in 2 parts:
- Upgrade the Control Plane Nodes
- Upgrade the Worker Nodes
First, run kubectl get nodes -o wide to see all the nodes.
Kubernetes Control Plane Upgrade: 1.23.17 -> 1.24.17
- Drain the node:
kubectl drain --ignore-daemonsets --delete-emptydir-data <node>
- ssh into the node, then run the next commands to add the necessary keys and update the node:
ssh -i ~/.ssh/key <user>@<ip>
echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.24/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.24/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
chmod +x /etc/apt/keyrings/kubernetes-apt-keyring.gpg
apt update
For The First Master Node
- Run the following command to list the available k8s versions:
apt-cache madison kubeadm | grep 1.24
- Run the command to upgrade kubeadm
apt-mark unhold kubeadm &&
apt-get update &&
apt-get install -y kubeadm='1.24.17-1.1' &&
apt-mark hold kubeadm
- Run the command to upgrade the node:
kubeadm upgrade apply v1.24.17 --ignore-preflight-errors=CoreDNSUnsupportedPlugins
- Run the command to upgrade kubelet and kubectl and then finally restart the kubelet:
apt-mark unhold kubelet kubectl &&
sudo apt-get update &&
sudo apt-get install -y kubelet='1.24.17-1.1' kubectl='1.24.17-1.1' &&
sudo apt-mark hold kubelet kubectl && systemctl daemon-reload &&
systemctl restart kubelet
- Uncordon the node:
kubectl uncordon <node>
For Each Of The Rest Of The Master Nodes
- Drain the node:
kubectl drain --ignore-daemonsets --delete-emptydir-data <node>
- ssh into the node
ssh -i ~/.ssh/key <user>@<ip>
- Check available kubelet & kubectl versions(Minor version upgrade is ok e.g 1.24.17):
apt-cache madison kubeadm | grep 1.24
- Run upgrade kubeadm
apt-mark unhold kubeadm &&
apt-get install -y kubeadm='1.24.17-00' &&
apt-mark hold kubeadm
- Run the command to upgrade the node:
kubeadm upgrade node --ignore-preflight-errors=CoreDNSUnsupportedPlugins
- Run the command to upgrade kubelet and kubectl and then finally restart the kubelet:
apt-mark unhold kubelet kubectl &&
apt-get update &&
apt-get install -y kubelet='1.24.17-00' kubectl='1.24.17-00' &&
apt-mark hold kubelet kubectl &&
systemctl daemon-reload &&
systemctl restart kubelet
- Uncordon the node:
kubectl uncordon <node>
Kubernetes Worker Upgrade: 1.23.17 -> 1.24.17
For Each Of The Worker Nodes
- Drain the node:
kubectl drain --ignore-daemonsets --delete-emptydir-data <node>
- ssh into the node:
ssh -i ~/.ssh/key <user>@<ip>
- Run the following command to list the available k8s versions:
apt update && apt-cache madison kubeadm | grep 1.24
- Run the command to upgrade kubeadm, kubelet and kubectl and then finally restart the kubelet:
apt-mark unhold kubeadm &&
apt-get install -y kubeadm='1.24.17-1.1' &&
apt-mark hold kubeadm && kubeadm upgrade node &&
apt-mark unhold kubelet kubectl &&
apt-get install -y kubelet='1.24.17-1.1' kubectl='1.24.17-1.1' &&
apt-mark hold kubelet kubectl && systemctl daemon-reload &&
systemctl restart kubelet
- Uncordon the node:
kubectl uncordon <node>
At this point, we have successfully upgraded the Kubernetes cluster from 1.23.17 -> 1.24.17.
kubernetesbare-metalupgrade