DEV Community

loading...

Automated Upgrades for k3s

kasuboski profile image Josh Kasuboski Originally published at joshkasuboski.com on ・1 min read

My cluster was falling behind the latest k3s version. Time to upgrade.

Enter the System Upgrade Controller

I basically just did the instructions linked here.

It deploys the system upgrade controller into its own namespace where it won't do anything yet.

You have to give it some plans.

It will read Plans in that same namespace and run the specified image. I used the plan linked above. Instead of tying it to a specific version I set it to the latest channel.

# 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/master
operator: In
values:
- "true"
serviceAccountName: system-upgrade
upgrade:
image: rancher/k3s-upgrade
channel: https://update.k3s.io/v1-release/channels/stable
---
# 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/master
operator: DoesNotExist
prepare:
args:
- prepare
- server-plan
image: rancher/k3s-upgrade:v1.17.4-k3s1
serviceAccountName: system-upgrade
upgrade:
image: rancher/k3s-upgrade
channel: https://update.k3s.io/v1-release/channels/stable

You'll notice there are actually 2 plans. One applied to the master nodes and the other the worker nodes. This lets you upgrade the master node to the new version before the workers.

The entire process took maybe 5 minutes for my 3 node cluster. I was able to kubectl get nodes periodically and watch the progress.

Discussion (0)

Forem Open with the Forem app