Review release notes for Kubernetes versions on standard support - Amazon EKS

Review release notes for Kubernetes versions on standard support

This topic gives important changes to be aware of for each Kubernetes version in standard support. When upgrading, carefully review the changes that have occurred between the old and new versions for your cluster.

Note

For 1.24 and later clusters, officially published Amazon EKS AMIs include containerd as the only runtime. Kubernetes versions earlier than 1.24 use Docker as the default runtime. These versions have a bootstrap flag option that you can use to test out your workloads on any supported cluster with containerd. For more information, see Migrate from dockershim to containerd.

Kubernetes 1.31

Kubernetes 1.31 is now available in Amazon EKS. For more information about Kubernetes 1.31, see the official release announcement.

Important
  • The kubelet flag --keep-terminated-pod-volumes deprecated since 2017 has been removed as part of the v1.31 release. This change impacts how terminated pod volumes are handled by the kubelet. If you are using this flag in your node configurations, you must update your bootstrap scripts and launch templates to remove it before upgrading.

  • The beta VolumeAttributesClass feature gate and API resource is enabled in Amazon EKS v1.31. This feature allows cluster operators to modify mutable properties of Persistent Volumes (PVs) managed by compatible CSI Drivers, including the Amazon EBS CSI Driver. To leverage this feature, ensure that your CSI Driver supports the VolumeAttributesClass feature (for the Amazon EBS CSI Driver, upgrade to version v1.35.0 or later to automatically enable the feature). You will be able to create VolumeAttributesClass objects to define the desired volume attributes, such as volume type and throughput, and associate them with your Persistent Volume Claims (PVCs). See the official Kubernetes documentation as well as the documentation of your CSI driver for more information.

  • Kubernetes support for AppArmor has graduated to stable and is now generally available for public use. This feature allows you to protect your containers with AppArmor by setting the appArmorProfile.type field in the container’s securityContext. Prior to Kubernetes v1.30, AppArmor was controlled by annotations. Starting with v1.30, it is controlled using fields. To leverage this feature, we recommend migrating away from annotations and using the appArmorProfile.type field to ensure that your workloads are compatible.

  • The PersistentVolume last phase transition time feature has graduated to stable and is now generally available for public use in Kubernetes v1.31. This feature introduces a new field, .status.lastTransitionTime, in the PersistentVolumeStatus, which provides a timestamp of when a PersistentVolume last transitioned to a different phase. This enhancement allows for better tracking and management of PersistentVolumes, particularly in scenarios where understanding the lifecycle of volumes is important.

For the complete Kubernetes 1.30 changelog, see https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.31.md

Kubernetes 1.30

Kubernetes 1.30 is now available in Amazon EKS. For more information about Kubernetes 1.30, see the official release announcement.

Important
  • Starting with Amazon EKS version 1.30 or newer, any newly created managed node groups will automatically default to using Amazon Linux 2023 (AL2023) as the node operating system. Previously, new node groups would default to Amazon Linux 2 (AL2). You can continue to use AL2 by choosing it as the AMI type when creating a new node group.

  • With Amazon EKS 1.30, the topology.k8s.aws/zone-id label is added to worker nodes. You can use Availability Zone IDs (AZ IDs) to determine the location of resources in one account relative to the resources in another account. For more information, see Availability Zone IDs for your AWS resources in the AWS RAM User Guide.

  • Starting with 1.30, Amazon EKS no longer includes the default annotation on the gp2 StorageClass resource applied to newly created clusters. This has no impact if you are referencing this storage class by name. You must take action if you were relying on having a default StorageClass in the cluster. You should reference the StorageClass by the name gp2. Alternatively, you can deploy the Amazon EBS recommended default storage class by setting the defaultStorageClass.enabled parameter to true when installing v1.31.0 or later of the aws-ebs-csi-driver add-on.

  • The minimum required IAM policy for the Amazon EKS cluster IAM role has changed. The action ec2:DescribeAvailabilityZones is required. For more information, see Amazon EKS cluster IAM role.

For the complete Kubernetes 1.30 changelog, see https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.30.md.

Kubernetes 1.29

Kubernetes 1.29 is now available in Amazon EKS. For more information about Kubernetes 1.29, see the official release announcement.

Important
  • The deprecated flowcontrol.apiserver.k8s.io/v1beta2 API version of FlowSchema and PriorityLevelConfiguration are no longer served in Kubernetes v1.29. If you have manifests or client software that uses the deprecated beta API group, you should change these before you upgrade to v1.29.

  • The .status.kubeProxyVersion field for node objects is now deprecated, and the Kubernetes project is proposing to remove that field in a future release. The deprecated field is not accurate and has historically been managed by kubelet - which does not actually know the kube-proxy version, or even whether kube-proxy is running. If you’ve been using this field in client software, stop - the information isn’t reliable and the field is now deprecated.

  • In Kubernetes 1.29 to reduce potential attack surface, the LegacyServiceAccountTokenCleanUp feature labels legacy auto-generated secret-based tokens as invalid if they have not been used for a long time (1 year by default), and automatically removes them if use is not attempted for a long time after being marked as invalid (1 additional year by default). To identify such tokens, a you can run:

    kubectl get cm kube-apiserver-legacy-service-account-token-tracking -n kube-system

For the complete Kubernetes 1.29 changelog, see https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.29.md#changelog-since-v1280.

Kubernetes 1.28

Kubernetes 1.28 is now available in Amazon EKS. For more information about Kubernetes 1.28, see the official release announcement.

  • Kubernetes v1.28 expanded the supported skew between core node and control plane components by one minor version, from n-2 to n-3, so that node components (kubelet and kube-proxy) for the oldest supported minor version can work with control plane components (kube-apiserver, kube-scheduler, kube-controller-manager, cloud-controller-manager) for the newest supported minor version.

  • Metrics force_delete_pods_total and force_delete_pod_errors_total in the Pod GC Controller are enhanced to account for all forceful pods deletion. A reason is added to the metric to indicate whether the pod is forcefully deleted because it’s terminated, orphaned, terminating with the out-of-service taint, or terminating and unscheduled.

  • The PersistentVolume (PV) controller has been modified to automatically assign a default StorageClass to any unbound PersistentVolumeClaim with the storageClassName not set. Additionally, the PersistentVolumeClaim admission validation mechanism within the API server has been adjusted to allow changing values from an unset state to an actual StorageClass name.

For the complete Kubernetes 1.28 changelog, see https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.28.md#changelog-since-v1270.