Lesson 16: Conclusion and Next Steps
With Node 1 added as a worker in the previous lesson, the full 4-node RKE2 cluster is operational. What started as a single k3s cluster has become a highly available control plane with encrypted pod networking and replicated storage, all without taking the old cluster offline until the new one was ready to serve traffic.
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This is the 16th lesson of the guide Migrating from k3s to RKE2. Make sure you have completed the previous lesson before continuing here. The full list of lessons in the guide can be found in the overview.
| Component | Technology |
|---|---|
| Distribution | RKE2 |
| OS | Rocky Linux 10 |
| CNI | Canal with WireGuard encryption |
| Storage | Longhorn (2 replicas) |
| Ingress | Traefik + Hetzner Load Balancer |
| Certificates | cert-manager with Let’s Encrypt |
The three control plane nodes provide etcd quorum tolerance, allowing any single node to go down without affecting cluster operations. Node 1 serves as a dedicated worker, keeping workload scheduling separate from control plane responsibilities. All four nodes participate in the WireGuard mesh and Longhorn storage pool.
With the cluster running, there are several directions to take it further.
The cluster currently has no visibility into resource usage, pod health trends, or alerting. Setting up Prometheus and Grafana (either through the Rancher Monitoring stack or a standalone kube-prometheus-stack Helm chart) provides dashboards for cluster health, resource consumption, and application metrics. Pairing this with Alertmanager means we get notified before problems become outages.
Deploying workloads manually with kubectl apply works for getting started, but does not scale.
A GitOps tool like Flux or ArgoCD watches a Git repository and automatically reconciles the cluster state to match.
This turns our Git repository into the single source of truth for what runs on the cluster, with full audit trails and easy rollbacks.
RKE2 releases new versions regularly with security patches and Kubernetes updates. The System Upgrade Controller automates rolling upgrades across the cluster, draining nodes one at a time and upgrading them in sequence without downtime.
An automated upgrade replaces the RKE2 data directory, which means the runc v1.3.4 workaround from Lesson 5 will be overwritten. Check whether the upstream runc regression has been fixed in the new RKE2 release before upgrading. If not, reapply the patch on each node after the upgrade completes.
We configured etcd snapshots to run every 6 hours in Lesson 5, but a complete backup strategy should also cover Longhorn volumes and application data. Velero can snapshot both Kubernetes resources and persistent volumes to an external object store like S3, providing disaster recovery across the entire cluster state.
For those interested in building Kubernetes clusters from the ground up, Building a production-ready Kubernetes cluster from scratch is a companion guide that walks through assembling a Raspberry Pi cluster, from hardware to a fully operational Kubernetes environment.
For the backstory on how this migration started, New K3s agent node for our cluster covers the original k3s expansion that eventually led to the decision to move to RKE2.
Lesson Conclusion
Congratulations! The migration from k3s to RKE2 is complete, with a 4-node cluster running enterprise-grade Kubernetes. You have completed this lesson and you can now continue with the next one.
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