Container Service for Kubernetes (ACK) provides container-centric solutions based on open source Kubernetes. As new Kubernetes versions are released, the list of Kubernetes versions supported by ACK also changes. New Kubernetes versions are added to the list and outdated Kubernetes versions are discontinued. This topic describes how ACK supports different Kubernetes versions, including the release cycle, support policies, and risks of using outdated Kubernetes versions.
Release notes
The following table describes the Kubernetes versions that are supported by ACK clusters and ACK Serverless clusters.
Version | Status | Release date (ACK) | Discontinue date (ACK) |
Released | June 2024 | June 2026 | |
Released | October 2023 | October 2025 | |
Released | April 2023 | April 2025 | |
Released | September 2022 | September 2024 | |
Discontinued | December 2021 | October 2023 | |
Discontinued | April 2021 | April 2023 | |
Discontinued | September 2020 | September 2022 | |
Discontinued | February 2020 | June 2022 | |
1.14 | Discontinued | August 2019 | July 2021 |
Discontinued | March 2019 | December 2020 |
Release cycle
Starting from January 1, 2020, ACK supports only even-numbered Kubernetes minor versions, such as Kubernetes 1.26, 1.28, and 1.30.
After the Kubernetes community releases a new even-numbered minor version, ACK performs a risk assessment and consistency test on the version. You can create clusters of the new version and update existing clusters to the new version after the new Kubernetes version passes the tests. In most cases, the preparations take two weeks and the duration varies based on the differences between versions.
After the Kubernetes community releases a new patch version for an even-numbered minor version, ACK determines whether to release the patch version based on the risk level of the issue fixed by the patch version. In most cases, ACK requires about 24 hours to perform a risk assessment and consistency test on a patch version that fixes critical issues, such as high-risk security vulnerabilities. Then, ACK allows you to create clusters of the new version and update existing clusters to the new version.
Version description
The Kubernetes versions supported by ACK follow the semantic versioning scheme in the x.y.z-aliyun.n format. x.y.z is the open source Kubernetes version. x is the major version, y is the minor version, z is the patch version, and n is the ACK patch version. For example, version 1.30.1-aliyun.1 is based on open source Kubernetes 1.30.1. For more information about Kubernetes versions, see Kubernetes Release Versioning.
Rules for supporting Kubernetes versions
Cluster creation
ACK allows you to create clusters of the latest three even-numbered minor versions. For example, the latest minor versions are Kubernetes 1.26, 1.28, and 1.30. When ACK starts to support Kubernetes 1.30, Kubernetes 1.24 is discontinued and you can no longer create clusters of Kubernetes 1.24. In addition, the outdated patch version is no longer available.
Cluster update
ACK allows you to update ACK clusters from a minor version to the following minor version. You cannot skip minor versions when you update ACK clusters or roll back your ACK clusters to an earlier version. For example, if your cluster runs Kubernetes 1.26 and you want to update the cluster to Kubernetes 1.30, you need to first update the cluster to Kubernetes 1.28 and then to Kubernetes 1.30.
ACK allows you to update an ACK cluster only to the latest patch version. You cannot update your cluster to outdated patch versions.
Technical support
Alibaba Cloud provides technical support for the latest three even-numbered minor versions. Technical support provided by Alibaba Cloud includes consultation, online tutorials, and troubleshooting.
Risks of outdated Kubernetes versions
Security and stability risks exist in outdated Kubernetes versions. We recommend that you update your clusters that use outdated Kubernetes versions at the earliest opportunity. For more information about cluster updates, see Manually update ACK clusters.
ACK provides the following support policies for clusters that run outdated Kubernetes versions:
Stop releasing new features
Stop fixing feature and security issues
Provide limited technical support
ACK does not guarantee that technical support can be provided at the first time except for issues related to cluster and component updates.
Reserve the right to force the clusters that run outdated Kubernetes versions to update
For availability and security purposes, after the Kubernetes version of a cluster becomes outdated, ACK forces the cluster to update to the earliest Kubernetes version supported by ACK. For example, if your cluster runs Kubernetes 1.20 and ACK supports Kubernetes versions 1.26, 1.28, and 1.30, ACK forces your cluster to update to 1.26.
ACK will send notifications to you by text messages, emails, or internal messages at least one month before the update. Pay attention to the notifications and prepare for the update in advance.
References
We recommend that you learn the updates and usage notes of each Kubernetes version before you update your cluster. For more information about cluster updates, see Manually update ACK clusters.