I’m migrating from MicroK8s to K3s. This post explains the installation and (re)configuration steps that I took including verification steps:

1. Install K3s
2. Use standalone kubectl and update ${KUBECONFIG} (~/.kube/config)
3. Install System Upgrade Controller
4. Install kube-prometheus stack (including the Prometheus Operator)
5. Disable Grafana and Node Exporter
6. Tweak default scrapeInterval
7. Install Tailscale Operator
8. Create Prometheus and Alertmanager Ingresses
9. Patch Prometheus and Alertmanager externalUrls
10. Tweak Prometheus resource to allow any serviceMonitors
11. Tweak Prometheus resource to allow any proemtheusRules

MicroK8s

Why abandon MicroK8s? I’ve been using MicroK8s for several years without issue but, after upgrading to Ubuntu 25.10 which includes a Rust replacement for sudo (and doesn’t support sudo -E), I created a problem for myself with MicroK8s and have been unable to restore a working Kubernetes cluster. I took the opportunity to reassess my distribution and have long thought to switch to K3s.