Best Approach and Tools for Upgrading and Rolling Back Kubernetes Cluster (v1.29 to v1.30+)

General Discussions
1

Hi Kubernetes Community,

I’m currently running an on-premises Kubernetes cluster on version 1.29, and I plan to upgrade to 1.30, with the eventual goal of moving to the latest stable version. My primary concern is ensuring a smooth upgrade process while maintaining the ability to roll back in case of any technical issues during the upgrade.

Here’s the full scenario:

  1. Cluster Details:

    • On-premises environment.
    • Deployed using kubeadm (though I’m open to other tools if necessary).
    • Multiple worker and control plane nodes.
    • Critical applications are running on the cluster, so downtime must be minimal.

  2. Upgrade Goals:

    • Upgrade to Kubernetes 1.30 with all associated components (e.g., kubeadm, kubelet, kube-proxy, etc.).
    • Test application compatibility and performance after the upgrade.
    • Ensure that any breaking changes in the new version can be mitigated.

  3. Rollback Requirement:

    • I’d like a reliable way to roll back to version 1.29 if issues arise, without breaking the cluster or applications.
    • Data integrity (e.g., persistent volumes, etcd snapshots) must remain intact during the rollback process.

Questions:

  1. Is there a specific tool or strategy you recommend for handling Kubernetes upgrades and rollbacks in an on-prem environment?
  2. What’s the best way to back up the cluster state (etcd, cluster configuration, etc.) to facilitate a rollback?
  3. Are there any tools or practices that allow a blue-green upgrade or canary-style testing for Kubernetes clusters?
  4. If you’ve faced a similar situation, what challenges should I expect, and how can I best prepare for them?

Things I’ve Considered:

  • Using etcdctl to back up and restore etcd snapshots for rollback.
  • Staging the upgrade in a test environment, but replicating production traffic is difficult.
  • Tools like Cluster API or Velero for backup and migration, though I’m not sure they can handle complete cluster rollback scenarios.

I’d greatly appreciate your insights on the best practices, tools, or workflows to achieve a reliable upgrade process with rollback capabilities. Thanks in advance for your advice! :blush: