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.

I couldn’t summarize this in a title (even with an LLM’s help):

I wanted to:

1. Run a Tailscale service discovery agent
2. On a Tailscale node outside of the Kubernetes cluster
3. Using Podman Quadlet
4. Accessing it from the Kubernetes Cluster using the Tailscale’s egress proxy
5. Accessing the proxy with a kube-prometheus ScrapeConfig
6. In order that Prometheus would scrape the container for Tailscale client metrics

Long-winded? Yes but I had an underlying need in running the Tailscale Service Discoovery remotely and this configuration helped me achieve that.

Spent time today yak-shaving which resulted in an unplanned migration from MicroK8s ‘prometheus’ add-on to the new and not fully-documented ‘observability’ add-on:

sudo microk8s.enable prometheus

Infer repository core for addon prometheus
DEPRECATION WARNING: 'prometheus' is deprecated and will soon be removed. Please use 'observability' instead.
...

The reason for the name change is unclear.

It’s unclear whether there’s a difference in the primary components that are installed too (I’d thought Grafana wasn’t included in ‘prometheus’), (Grafana) Loki and (Grafana) Tempo definitely weren’t included and I don’t want them either.