Upgrading K3s to 1.26

Note: For the Platform Team: Local Cluster K3s Upgrade

If you are upgrading K3s of the local cluster, you would need to remove the existing PodSecurityPolicy resources.

We have only one of them under the chart aws-node-termination-handler

Patch the helm Chart to disable the psp resource.

kubectl patch helmchart aws-node-termination-handler -n kube-system --type='json' -p='[{"op": "add", "path": "/spec/set/rbac.pspEnabled", "value": "false"}]'

This will trigger the removal of the PSP resource.

The traefik is deployed as daemonset in the local clusters. You would need to restart the daemonset instead when following the steps given in Post Upgrade Patch (broken link)

Deploy the system-upgrade-controller:

kubectl apply -f https://assets.master.k3s.getvisibility.com/system-upgrade-controller/v0.13.1/system-upgrade-controller.yaml

Create the upgrade plan

Note: The key version has the version of the K3s that the cluster will be upgraded to.

cat > upgrade-plan-server.yaml << EOF
---
# Server plan
apiVersion: upgrade.cattle.io/v1
kind: Plan
metadata:
  name: server-plan
  namespace: system-upgrade
spec:
  concurrency: 1
  cordon: true
  nodeSelector:
    matchExpressions:
    - key: node-role.kubernetes.io/control-plane
      operator: In
      values:
      - "true"
  serviceAccountName: system-upgrade
  upgrade:
    image: rancher/k3s-upgrade
  version: v1.26.10+k3s1
EOF

If you are also running a worker node then execute this too:

cat > upgrade-plan-agent.yaml << EOF
---
# Agent plan
apiVersion: upgrade.cattle.io/v1
kind: Plan
metadata:
  name: agent-plan
  namespace: system-upgrade
spec:
  concurrency: 1
  cordon: true
  nodeSelector:
    matchExpressions:
    - key: node-role.kubernetes.io/control-plane
      operator: DoesNotExist
  prepare:
    args:
    - prepare
    - server-plan
    image: rancher/k3s-upgrade
  serviceAccountName: system-upgrade
  upgrade:
    image: rancher/k3s-upgrade
  version: v1.26.10+k3s1
EOF

Run the upgrade plan:

kubectl apply -f upgrade-plan-server.yaml

In the case of a Worker node execute this too:

kubectl apply -f upgrade-plan-agent.yaml

Once the plan is executed, all pods will restart and take a few minutes to recover Check the status of all the pods:
```
watch kubectl get pods -A
```
Check if the K3s version has been upgraded:
```
kubectl get nodes
```

Delete the system-upgrade-controller:

kubectl delete -f https://assets.master.k3s.getvisibility.com/system-upgrade-controller/v0.13.1/system-upgrade-controller.yaml

Reference: Apply upgrade: https://docs.k3s.io/upgrades/automated#install-the-system-upgrade-controller