Upgrade notes

This page highlights breaking changes and important considerations for Kubernetes minor version upgrades. It is not a full changelog — for complete details, follow the official Kubernetes changelog link in each section.

If you are planning an upgrade, review the relevant version section before proceeding, paying close attention to pre-upgrade requirements and component changes.

Upgrade to 1.36

Official Kubernetes 1.36 changelog

What changes during upgrade

During an upgrade to Kubernetes 1.36, the following components are updated automatically:

• containerd is upgraded from 1.6.x to 2.2.x. The containerd, containerd.io, and runc apt packages are removed; containerd and runc are installed from upstream releases instead.
• Calico, CoreDNS and OpenEBS are upgraded. A rolling restart of DaemonSets occurs across nodes during the upgrade.
• kube-proxy mode is switched from iptables to nftables.
• serverscom-rbs-csi is installed as a new component. This is the Servers.com RBS CSI driver for persistent volume support.

Pre-upgrade requirements

Kubernetes 1.36 removes fallback compatibility with containerd 1.x. Before upgrading, verify that your workloads meet the following requirements:

• Container images: All images must use Schema 2 or OCI manifests. Pulling Schema 1 images (application/vnd.docker.distribution.manifest.v1+prettyjws) was deprecated in containerd v1.7 and is not supported in containerd 2.x.
• CRI integration: All CRI integrations must use CRI v1. CRI v1alpha2 is not present in containerd 2.0 or later, so anything depending on v1alpha2 will not work after the upgrade.
• Runtime plugins: Workloads must not depend on Go .so runtime plugins. These were removed before the 2.x line and are not supported in containerd 2.2.
• Custom containerd configuration: If you have modified the containerd TOML configuration, verify that your configuration is compatible with containerd v2 before upgrading. Incompatible settings may cause conflicts with the new version.

Component versions

Upgrade to 1.35

Official Kubernetes 1.35 changelog

What changes during upgrade

No breaking changes occur when upgrading to Kubernetes 1.35.

Component versions