Upgrade vSphere, CloudStack, Nutanix, or Snow cluster

How to perform a cluster upgrade for vSphere, CloudStack, Nutanix, or Snow cluster

EKS Anywhere provides the command upgrade, which allows you to upgrade various aspects of your EKS Anywhere cluster. When you run eksctl anywhere upgrade cluster -f ./cluster.yaml, EKS Anywhere runs a set of preflight checks to ensure your cluster is ready to be upgraded. EKS Anywhere then performs the upgrade, modifying your cluster to match the updated specification. The upgrade command also upgrades core components of EKS Anywhere and lets the user enjoy the latest features, bug fixes and security patches.

NOTE: If an upgrade fails, it is very important not to delete the Docker containers running the KinD bootstrap cluster. During an upgrade, the bootstrap cluster contains critical EKS Anywhere components. If it is deleted after a failed upgrade, they cannot be recovered.

Minor Version Upgrades

Kubernetes has minor releases three times per year and EKS Distro follows a similar cadence. EKS Anywhere will add support for new EKS Distro releases as they are released, and you are advised to upgrade your cluster when possible.

Cluster upgrades are not handled automatically and require administrator action to modify the cluster specification and perform an upgrade. You are advised to upgrade your clusters in development environments first and verify your workloads and controllers are compatible with the new version.

Cluster upgrades are performed in place using a rolling process (similar to Kubernetes Deployments). Upgrades can only happen one minor version at a time (e.g. 1.24 -> 1.25). Control plane components will be upgraded before worker nodes.

A new VM is created with the new version and then an old VM is removed. This happens one at a time until all the control plane components have been upgraded.

Core component upgrades

EKS Anywhere upgrade also supports upgrading the following core components:

  • Core CAPI
  • CAPI providers
  • Cilium CNI plugin
  • Cert-manager
  • Etcdadm CAPI provider
  • EKS Anywhere controllers and CRDs
  • GitOps controllers (Flux) - this is an optional component, will be upgraded only if specified

The latest versions of these core EKS Anywhere components are embedded into a bundles manifest that the CLI uses to fetch the latest versions and image builds needed for each component upgrade. The command detects both component version changes and new builds of the same versioned component. If there is a new Kubernetes version that is going to get rolled out, the core components get upgraded before the Kubernetes version. Irrespective of a Kubernetes version change, the upgrade command will always upgrade the internal EKS Anywhere components mentioned above to their latest available versions. All upgrade changes are backwards compatible.

Specifically for Snow provider, a new Admin instance is needed when upgrading to the new versions of EKS Anywhere. See Upgrade EKS Anywhere AMIs in Snowball Edge devices to upgrade and use a new Admin instance in Snow devices. After that, ugrades of other components can be done as described in this document.

Check upgrade components

Before you perform an upgrade, check the current and new versions of components that are ready to upgrade by typing:

Management Cluster

eksctl anywhere upgrade plan cluster -f mgmt-cluster.yaml

Workload Cluster

eksctl anywhere upgrade plan cluster -f workload-cluster.yaml --kubeconfig mgmt/mgmt-eks-a-cluster.kubeconfig

The output should appear similar to the following:

Worker node group name not specified. Defaulting name to md-0.
Warning: The recommended number of control plane nodes is 3 or 5
Worker node group name not specified. Defaulting name to md-0.
Checking new release availability...
NAME                     CURRENT VERSION                 NEXT VERSION
EKS-A                    v0.0.0-dev+build.1000+9886ba8   v0.0.0-dev+build.1105+46598cb
cluster-api              v1.0.2+e8c48f5                  v1.0.2+1274316
kubeadm                  v1.0.2+92c6d7e                  v1.0.2+aa1a03a
vsphere                  v1.0.1+efb002c                  v1.0.1+ef26ac1
kubadm                   v1.0.2+f002eae                  v1.0.2+f443dcf
etcdadm-bootstrap        v1.0.2-rc3+54dcc82              v1.0.0-rc3+df07114
etcdadm-controller       v1.0.2-rc3+a817792              v1.0.0-rc3+a310516

To the format output in json, add -o json to the end of the command line.

Performing a cluster upgrade

To perform a cluster upgrade you can modify your cluster specification kubernetesVersion field to the desired version.

As an example, to upgrade a cluster with version 1.24 to 1.25 you would change your spec

apiVersion: anywhere.eks.amazonaws.com/v1alpha1
kind: Cluster
metadata:
  name: dev
spec:
  controlPlaneConfiguration:
    count: 1
    endpoint:
      host: "198.18.99.49"
    machineGroupRef:
      kind: VSphereMachineConfig
      name: dev
      ...
  kubernetesVersion: "1.25"
      ...

NOTE: If you have a custom machine image for your nodes you may also need to update your vsphereMachineConfig with a new template.

and then you will run the command

Management Cluster

eksctl anywhere upgrade cluster -f mgmt-cluster.yaml

Workload Cluster

eksctl anywhere upgrade cluster -f workload-cluster.yaml --kubeconfig mgmt/mgmt-eks-a-cluster.kubeconfig

This will upgrade the cluster specification (if specified), upgrade the core components to the latest available versions and apply the changes using the provisioner controllers.

Example output:

✅ control plane ready
✅ worker nodes ready
✅ nodes ready
✅ cluster CRDs ready
✅ cluster object present on workload cluster
✅ upgrade cluster kubernetes version increment
✅ validate immutable fields
🎉 all cluster upgrade preflight validations passed
Performing provider setup and validations
Pausing EKS-A cluster controller reconcile
Pausing Flux kustomization
GitOps field not specified, pause flux kustomization skipped
Creating bootstrap cluster
Installing cluster-api providers on bootstrap cluster
Moving cluster management from workload to bootstrap cluster
Upgrading workload cluster
Moving cluster management from bootstrap to workload cluster
Applying new EKS-A cluster resource; resuming reconcile
Resuming EKS-A controller reconciliation
Updating Git Repo with new EKS-A cluster spec
GitOps field not specified, update git repo skipped
Forcing reconcile Git repo with latest commit
GitOps not configured, force reconcile flux git repo skipped
Resuming Flux kustomization
GitOps field not specified, resume flux kustomization skipped

During the upgrade process, EKS Anywhere pauses the cluster controller reconciliation by adding the paused annotation anywhere.eks.amazonaws.com/paused: true to the EKS Anywhere cluster, provider datacenterconfig and machineconfig resources, before the components upgrade. After upgrade completes, the annotations are removed so that the cluster controller resumes reconciling the cluster.

Though not recommended, you can manually pause the EKS Anywhere cluster controller reconciliation to perform extended maintenance work or interact with Cluster API objects directly. To do it, you can add the paused annotation to the cluster resource:

kubectl annotate clusters.anywhere.eks.amazonaws.com ${CLUSTER_NAME} -n ${CLUSTER_NAMESPACE} anywhere.eks.amazonaws.com/paused=true

After finishing the task, make sure you resume the cluster reconciliation by removing the paused annotation, so that EKS Anywhere cluster controller can continue working as expected.

kubectl annotate clusters.anywhere.eks.amazonaws.com ${CLUSTER_NAME} -n ${CLUSTER_NAMESPACE} anywhere.eks.amazonaws.com/paused-

Upgradeable Cluster Attributes

EKS Anywhere upgrade supports upgrading more than just the kubernetesVersion, allowing you to upgrade a number of fields simultaneously with the same procedure.

Upgradeable Attributes

Cluster:

  • kubernetesVersion
  • controlPlaneConfig.count
  • controlPlaneConfigurations.machineGroupRef.name
  • workerNodeGroupConfigurations.count
  • workerNodeGroupConfigurations.machineGroupRef.name
  • etcdConfiguration.externalConfiguration.machineGroupRef.name
  • identityProviderRefs (Only for kind:OIDCConfig, kind:AWSIamConfig is immutable)
  • gitOpsRef (Once set, you can’t change or delete the field’s content later)

VSphereMachineConfig:

  • datastore
  • diskGiB
  • folder
  • memoryMiB
  • numCPUs
  • resourcePool
  • template
  • users

NutanixMachineConfig:

  • vcpusPerSocket
  • vcpuSockets
  • memorySize
  • image
  • cluster
  • subnet
  • systemDiskSize

SnowMachineConfig:

  • amiID
  • instanceType
  • physicalNetworkConnector
  • sshKeyName
  • devices
  • containersVolume
  • osFamily
  • network

OIDCConfig:

  • clientID
  • groupsClaim
  • groupsPrefix
  • issuerUrl
  • requiredClaims.claim
  • requiredClaims.value
  • usernameClaim
  • usernamePrefix

AWSIamConfig:

  • mapRoles
  • mapUsers

EKS Anywhere upgrade also supports adding more worker node groups post-creation. To add more worker node groups, modify your cluster config file to define the additional group(s). Example:

apiVersion: anywhere.eks.amazonaws.com/v1alpha1
kind: Cluster
metadata:
  name: dev
spec:
  controlPlaneConfiguration:
     ...
  workerNodeGroupConfigurations:
  - count: 2
    machineGroupRef:
      kind: VSphereMachineConfig
      name: my-cluster-machines
    name: md-0
  - count: 2
    machineGroupRef:
      kind: VSphereMachineConfig
      name: my-cluster-machines
    name: md-1
      ...

Worker node groups can use the same machineGroupRef as previous groups, or you can define a new machine configuration for your new group.

Resume upgrade after failure

EKS Anywhere supports re-running the upgrade command post-failure as an experimental feature. If the upgrade command fails, the user can manually fix the issue (when applicable) and simply rerun the same command. At this point, the CLI will skip the completed tasks, restore the state of the operation, and resume the upgrade process. The completed tasks are stored in the generated folder as a file named <clusterName>-checkpoint.yaml.

This feature is experimental. To enable this feature, export the following environment variable:
export CHECKPOINT_ENABLED=true

Troubleshooting

Attempting to upgrade a cluster with more than 1 minor release will result in receiving the following error.

✅ validate immutable fields
❌ validation failed    {"validation": "Upgrade preflight validations", "error": "validation failed with 1 errors: WARNING: version difference between upgrade version (1.21) and server version (1.19) do not meet the supported version increment of +1", "remediation": ""}
Error: failed to upgrade cluster: validations failed

For more errors you can see the troubleshooting section .