Kubernetes Framework

AKS Cluster Upgrade Guide

Check for Available AKS Cluster Upgrade

Navigate to Azure Portal:

Go to the Azure portal and search for Kubernetes services.

Check Current AKS Version:

Click on the Upgrade version option for the client you are upgrading to view the current AKS version.

Note:

When upgrading a supported AKS cluster, you can't skip Kubernetes minor versions. You must perform all upgrades sequentially by major version number. For example:

Upgrades between 1.14.x -> 1.15.x or 1.15.x -> 1.16.x are allowed.
Upgrades from 1.14.x -> 1.16.x are not allowed.

You can skip multiple versions only when upgrading from an unsupported version back to a supported version. For example:

Upgrades from an unsupported 1.10.x to a supported 1.12.x are allowed if available.

version. For example, you can perform an upgrade from an unsupported 1.10.x to a supported 1.12.x if available.

Upgrade an AKS Cluster

Back-Up and Delete PDB Policy:

To upgrade the AKS cluster, you must have contributor access to your user.

Backup PDBs:
kubectl get pdb -A -o yaml > backup.yaml

Delete PDBs:
kubectl delete --all pdb -A

Check PDBs:
kubectl get pdb -A

Upgrade AKS Cluster:

Execute the following command to upgrade the AKS cluster:

az aks upgrade --resource-group <myResourceGroup> --name <myAKSCluster> --kubernetes-version <KUBERNETES_VERSION>

Example:
az aks upgrade --resource-group stinsco1-ResGroup --name stinsco1-akscluster1-eastus --kubernetes-version 1.28.9

Restore PDB Policy:

Restore PDBs:
kubectl apply -f backup.yaml

Check PDBs:
kubectl get pdb -A

Confirm Upgrade:

To confirm the successful upgrade, recheck the cluster configuration:
az aks show --resource-group <myResourceGroup> --name <myAKSCluster> --query kubernetesVersion

Or again check the cluster configuration from the Azure portal.