K3s and MicroK8s — Lightweight Kubernetes Variants
Why they exist
Not every setup needs a full-scale Kubernetes cluster with all components turned on. Sometimes it’s just a couple of small nodes at the edge, or a developer’s laptop that needs a local cluster for testing. That’s where K3s and MicroK8s step in. Both are CNCF-certified, so the APIs are the same, but the packaging and philosophy are different.
How they behave in practice
K3s is stripped down to essentials. It comes as a single binary, pulls in dependencies automatically, and uses SQLite by default instead of etcd. In resource-constrained places — small servers, IoT gateways, ARM boards — this matters a lot. Admins can switch to etcd or another datastore if they want high availability.
MicroK8s is packaged as a snap. That makes install and upgrade very simple on Ubuntu, which is where it shines. Add-ons can be enabled on demand: DNS, ingress, metrics, storage. It can run on a single machine for local work or be joined into a small cluster.
At the end of the day, both still “speak Kubernetes.” Standard manifests work. Helm charts deploy fine. The main differences are footprint and ecosystem fit.
Technical profile
| Area | K3s | MicroK8s |
| Vendor | Rancher / SUSE | Canonical |
| Install method | Single binary, curl script | Snap package |
| Default datastore | SQLite | etcd |
| Targets | ARM/x86, edge nodes | Ubuntu desktops/servers, dev labs |
| Extras | Minimal, external add-ons | Built-in add-ons (DNS, ingress, storage, metrics) |
| Binary size | ~100 MB | Larger, modular |
| License | Apache 2.0 | Apache 2.0 |
Setup notes
K3s:
– One-liner install with a curl script.
– Bundles kubectl.
– For HA, external DB required (etcd, MySQL, Postgres).
MicroK8s:
– Install with ‘snap install microk8s –classic’.
– Add user to microk8s group.
– Enable add-ons as needed (dns, storage, ingress, etc.).
– Works best on Ubuntu; other distros may need extra steps.
Where it fits
– Edge nodes with tight CPU/RAM budgets.
– Developer laptops that need a quick Kubernetes API without heavy lifting.
– Training labs and workshops where fast reset/redeploy is important.
– Hybrid setups that combine full-blown clusters with small satellite ones.
Limits in real use
– SQLite in K3s is fine for single-node but not for scaling.
– Snap packaging in MicroK8s is convenient, but some enterprises don’t like snap in production.
– Neither has the enterprise integrations of OpenShift or Tanzu.
– When clusters grow, both may need tuning or migration to upstream Kubernetes.
Comparison snapshot
| Tool | Main strengths | Typical usage |
| K3s | Extremely small, simple to deploy, ARM-friendly | IoT, edge, small Linux hosts |
| MicroK8s | Snap-based, built-in add-ons, Ubuntu-native | Developers, training labs, Ubuntu clusters |
| Minikube | Single-node, easy start | Learning and testing only |
| OpenShift | Enterprise features, vendor support | Corporate datacenters |