rancher-system-upgrade-controller

Infra

Updated on July 31

Rancher System Upgrade Controller Overview

Secure your stack with a hardened Rancher System Upgrade Controller image freshly-built by Minimus. Minimus images always include the most up-to-date package version for all packages and dependencies contained in the image.

Rancher System Upgrade Controller is a Kubernetes-native controller for automating node upgrades. It introduces a Plan custom resource that defines upgrade policies. The controller schedules upgrade Jobs against selected nodes and tracks completion via node labels, enabling coordinated, declarative node lifecycle management without manual intervention.

Try It Out

Prerequisites: A running Kubernetes cluster with kubectl configured.

Deploy the controller to your cluster using the Minimus image:

kubectl apply -f https://github.com/rancher/system-upgrade-controller/releases/latest/download/system-upgrade-controller.yaml
kubectl set image deployment/system-upgrade-controller \
  system-upgrade-controller=reg.mini.dev/rancher-system-upgrade-controller \
  -n system-upgrade

Verify the controller is running:

kubectl rollout status deployment/system-upgrade-controller -n system-upgrade

You should see the confirmation:

deployment "system-upgrade-controller" successfully rolled out

Create a Plan

Once the controller is running, apply a Plan to upgrade nodes. Save the following to plan.yaml:

apiVersion: upgrade.cattle.io/v1
kind: Plan
metadata:
  name: k3s-server
  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
  channel: https://update.k3s.io/v1-release/channels/stable

Then apply it:

kubectl apply -f plan.yaml

For more Plan examples and configuration options, see the official Rancher System Upgrade Controller README.

Technical Considerations

The Rancher System Upgrade Controller image provided by Minimus is a slim, security-hardened alternative to the public image. The images are largely interchangeable, with a few differences as noted below.

Rancher System Upgrade Controller built by Minimus:

Runs as non-root by default for a security-first approach that protects against privilege escalation attacks.
Drill down on the version specification tab to see the default user, listening ports, entrypoint, volumes, environment variables, etc.

The Payoff

A hardened, minimal image that will remain more secure for the long run and accrue vulnerabilities at a slower rate.

See the risk reduction dashboard for a detailed CVE comparison over the past 30 days.
Review the compliance report to see the default hardening and security configurations for the image.

Terms & Info

Trademark

This catalog is published by Minimus. All product names, logos, and marks, other than those belonging to Minimus, shown are owned by their respective rights holders and appear here only to identify the open source software each image contains. Minimus claims no ownership of those marks and implies no affiliation with, endorsement by, certification by, or sponsorship by any rights holder.

Disclaimer

Images are provided "as-is" without warranty of any kind. "Hardened" refers to the security configuration applied at the time of build and does not constitute a guarantee of ongoing security or absence of vulnerabilities. The free tier is provided without support, SLA, or guaranteed patching timelines. Security updates may be applied to paid subscriptions before or instead of free tier images. By pulling or using any image you agree to our Terms of Use.