Updating the cluster with same Kubernetes version

Introduction to ClusterStack Releases

Syself is releasing a new version of the ClusterStacks every two to three weeks. These releases may contain minor updates, such as a Kubernetes patch version, or the version of some cluster components or node images.

This guide will detail the process of updating from to v19 .

Preparing the clusterstack object

Check if autoSubscribe is set to true or false in your clusterstack object and follow the steps for your case:

note

The autoSubscribe key in the clusterstack object indicates that Syself Autopilot will automatically fetch the latest ClusterStackRelease version and make it available for use.

The latest version is automatically available for you, but you still need to specify the versions in between.

For that, add ["v18"] to the spec.versions array in your ClusterStack:

clusterstack.yaml yaml

apiVersion: clusterstack.x-k8s.io/v1alpha1 kind: ClusterStack metadata: name: hetzner-apalla-1-27 spec: provider: hetzner name: apalla kubernetesVersion: '1.27' channel: stable autoSubscribe: true versions: ["v18"] // [!code focus] providerRef: name: hetzner-apalla-1-27 kind: HetznerClusterStackReleaseTemplate apiVersion: infrastructure.clusterstack.x-k8s.io/v1alpha1

You need to specify the ClusterStackRelease versions in between using the spec.versions array in your ClusterStack object.

The following is the complete (and shortest) tested upgrade path to go from your current version to hetzner-apalla-1-27-v19 :

clusterstack.yaml yaml

apiVersion: clusterstack.x-k8s.io/v1alpha1 kind: ClusterStack metadata: name: hetzner-apalla-1-27 spec: provider: hetzner name: apalla kubernetesVersion: '1.27' channel: stable autoSubscribe: false versions: ["v18","v19"] // [!code focus] providerRef: name: hetzner-apalla-1-27 kind: HetznerClusterStackReleaseTemplate apiVersion: infrastructure.clusterstack.x-k8s.io/v1alpha1

Checking the available ClusterStacksReleases

Check if the ClusterStackReleases you need are available with:

Note down the values of the NAME and K8S VERSION columns from the release you want to upgrade to. In this case, hetzner-apalla-1-27-v19 and v1.27.16 .

Upgrading the cluster object

Edit your cluster and change the spec.topology.class and spec.topology.version to match the NAME and K8S VERSION of the ClusterStackRelease, respectively.

This can be achieved either by editing the resource inside the management cluster, or by updating it in your GitOps repository.

cluster.yaml yaml

apiVersion: cluster.x-k8s.io/v1beta1 kind: Cluster metadata: name: mycluster spec: clusterNetwork: services: cidrBlocks: ['10.128.0.0/12'] pods: cidrBlocks: ['192.168.0.0/16'] serviceDomain: 'cluster.local' topology: class: hetzner-apalla-1-27-v18 // [!code focus] version: v1.27.15 // [!code focus] controlPlane: replicas: 3 workers: machineDeployments: - class: workeramd64hcloud name: md-0 replicas: 1 failureDomain: nbg1 variables: overrides: - name: workerMachineTypeHcloud value: cx31 variables: - name: SSHKeyNameHcloud value: - name: - name: region value: nbg1 - name: controlPlaneMachineTypeHcloud value: cx31

Now, your cluster will be updated (with no downtime!) to the cluster stack version you specified.

If you need to udate to another version, wait for the current update process to finish. You can check if it's done by checking the nodes in your cluster:

If you still have old nodes, this means the update is in progress. In this case, wait until the output shows only news nodes.