Release notes for standard support versions - Amazon EKS
Kubernetes 1.29Kubernetes 1.28Kubernetes 1.27Kubernetes 1.26

Release notes for standard support versions

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 Amazon EKS ended support for Dockershim.

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 -nkube-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.

Kubernetes 1.27

Kubernetes 1.27 is now available in Amazon EKS. For more information about Kubernetes 1.27, see the official release announcement.

Important

  • The support for the alpha seccomp annotations seccomp.security.alpha.kubernetes.io/pod and container.seccomp.security.alpha.kubernetes.io annotations was removed. The alpha seccomp annotations was deprecated in 1.19, and with their removal in 1.27, seccomp fields will no longer auto-populate for Pods with seccomp annotations. Instead, use the securityContext.seccompProfile field for Pods or containers to configure seccomp profiles. To check whether you are using the deprecated alpha seccomp annotations in your cluster, run the following command:

    kubectl get pods --all-namespaces -o json | grep -E 'seccomp.security.alpha.kubernetes.io/pod|container.seccomp.security.alpha.kubernetes.io'

  • The --container-runtime command line argument for the kubelet was removed. The default container runtime for Amazon EKS has been containerd since 1.24, which eliminates the need to specify the container runtime. From 1.27 onwards, Amazon EKS will ignore the --container-runtime argument passed to any bootstrap scripts. It is important that you don't pass this argument to --kubelet-extra-args in order to prevent errors during the node bootstrap process. You must remove the --container-runtime argument from all of your node creation workflows and build scripts.

  • The kubelet in Kubernetes 1.27 increased the default kubeAPIQPS to 50 and kubeAPIBurst to 100. These enhancements allow the kubelet to handle a higher volume of API queries, improving response times and performance. When the demands for Pods increase, due to scaling requirements, the revised defaults ensure that the kubelet can efficiently manage the increased workload. As a result, Pod launches are quicker and cluster operations are more effective.

  • You can use more fine grained Pod topology to spread policies such as minDomain. This parameter gives you the ability to specify the minimum number of domains your Pods should be spread across. nodeAffinityPolicy and nodeTaintPolicy allow for an extra level of granularity in governing Pod distribution. This is in accordance to node affinities, taints, and the matchLabelKeys field in the topologySpreadConstraints of your Pod's specification. This permits the selection of Pods for spreading calculations following a rolling upgrade.

  • Kubernetes1.27 promoted to beta a new policy mechanism for StatefulSets that controls the lifetime of their PersistentVolumeClaims(PVCs). The new PVC retention policy lets you specify if the PVCs generated from the StatefulSet spec template will be automatically deleted or retained when the StatefulSet is deleted or replicas in the StatefulSet are scaled down.

  • The goaway-chance option in the Kubernetes API server helps prevent HTTP/2 client connections from being stuck on a single API server instance, by randomly closing a connection. When the connection is closed, the client will try to reconnect, and will likely land on a different API server as a result of load balancing. Amazon EKS version 1.27 has enabled goaway-chance flag. If your workload running on Amazon EKS cluster uses a client that is not compatible with HTTP GOAWAY, we recommend that you update your client to handle GOAWAY by reconnecting on connection termination.

For the complete Kubernetes 1.27 changelog, see https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.27.md#changelog-since-v1260.

Kubernetes 1.26

Kubernetes 1.26 is now available in Amazon EKS. For more information about Kubernetes 1.26, see the official release announcement.

Important

Kubernetes 1.26 no longer supports CRI v1alpha2. This results in the kubelet no longer registering the node if the container runtime doesn't support CRI v1. This also means that Kubernetes 1.26 doesn't support containerd minor version 1.5 and earlier. If you're using containerd, you need to upgrade to containerd version 1.6.0 or later before you upgrade any nodes to Kubernetes 1.26. You also need to upgrade any other container runtimes that only support the v1alpha2. For more information, defer to the container runtime vendor. By default, Amazon Linux and Bottlerocket AMIs include containerd version 1.6.6.

  • Before you upgrade to Kubernetes 1.26, upgrade your Amazon VPC CNI plugin for Kubernetes to version 1.12 or later. If you don't upgrade to Amazon VPC CNI plugin for Kubernetes version 1.12 or later, the Amazon VPC CNI plugin for Kubernetes will crash. For more information, see Working with the Amazon VPC CNI plugin for Kubernetes Amazon EKS add-on.

  • The goaway-chance option in the Kubernetes API server helps prevent HTTP/2 client connections from being stuck on a single API server instance, by randomly closing a connection. When the connection is closed, the client will try to reconnect, and will likely land on a different API server as a result of load balancing. Amazon EKS version 1.26 has enabled goaway-chance flag. If your workload running on Amazon EKS cluster uses a client that is not compatible with HTTP GOAWAY, we recommend that you update your client to handle GOAWAY by reconnecting on connection termination.

For the complete Kubernetes 1.26 changelog, see https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.26.md#changelog-since-v1250.