What is k3s upgrade plan to upgrade from k3s v1.20.15+k3s1 to k3s v1.32.x+k3s1?

System Administration
1

I got answer via chatgpt but want to hear from experts here.
OS: Rocky Linux 9
Rancher also installed

2

If you're asking for input on upgrading from k3s v1.20.15+k3s1 to v1.32.x+k3s1, and you've already consulted ChatGPT, please share that response—along with the ChatGPT version. Expecting others to respond without seeing what you're comparing against isn't collaborative. It's not about competing with AI; it's about providing full context so the discussion is productive for everyone.

3

This is response from chatgpt:

Upgrading from K3s v1.20.15+k3s1 to K3s v1.32.x+k3s1 is a major multi-version jump across more than 10 Kubernetes versions, which introduces breaking changes, deprecated APIs, and possible storage/backend migrations.

Here's a structured K3s upgrade plan to perform this safely:

:repeat_button: 1. Understand K3s Upgrade Requirements

  • K3s upgrades must be done sequentially, one minor version at a time.
  • You cannot skip major Kubernetes versions (e.g., v1.20 → v1.25 directly is not supported).
  • Control plane nodes must be upgraded before agent nodes.

:date: 2. Determine the Upgrade Path

Your path would look like:

v1.20.15 → v1.21 → v1.22 → v1.23 → v1.24 → v1.25 → v1.26 → v1.27 → v1.28 → v1.29 → v1.30 → v1.31 → v1.32

Minimum steps: 12 upgrades.

For each upgrade, use the latest patch of that minor version (e.g., v1.21.14+k3s1).

:hammer_and_wrench: 3. Upgrade Strategy

A. Backup Everything

  • Use etcdctl or k3s etcd-snapshot save if using embedded etcd.
  • Backup /var/lib/rancher/k3s, manifests, and secrets.

B. Review Deprecated APIs

Each version drops or changes APIs. Pay attention to:

  • Ingress, PodSecurityPolicy, NetworkPolicy, CRDs

  • Use tools like:

    • kubent (Kubernetes deprecated API scanner)
    • pluto (Helm-deprecated API scanner)

C. Upgrade in Steps (per minor version)

For each upgrade:

  1. Download correct version:

    curl -sfL https://get.k3s.io | INSTALL_K3S_VERSION=v1.21.x+k3s1 sh -

  2. Upgrade control plane node(s).

  3. Wait for the node to return to Ready and check logs:

    kubectl get nodes
journalctl -u k3s

  4. Upgrade agent nodes:
    Same script but on agent nodes.

  5. Verify cluster health:

    kubectl get pods -A
kubectl get cs

:gear: 4. Automation Suggestions

  • Use Ansible or shell scripts to control upgrade steps.
  • Insert pauses and health checks between each step.
  • Keep audit trail of versions, errors, and success logs.

:test_tube: 5. Test in Staging

  • If your cluster is critical, replicate it in a VM or staging environment and test the full upgrade chain there.

:receipt: 6. Final Steps

  • Once at v1.32, validate workloads, storage drivers, CNI plugins, and CRDs.
  • Enable any new v1.32 features as needed.
  • Update Helm charts and controller versions to stay compatible.

Would you like a custom script or checklist for automating these upgrade steps version-by-version?

4

You’re testing my patience, @Ihattaren.

You still haven’t followed basic instructions:

Reference the source clearly. That means editing your reply to include:

“This is a reply I got from ChatGPT (version number)”

We’ve asked nicely. Please follow the guidelines so the discussion remains transparent and useful for everyone.