`liken`

A patch of crustose lichen. Each tile is one areole.

liken is a small operating system. It boots a machine directly into Kubernetes.

A machine runs the Linux kernel, k3s, and one small init process. There is no systemd, no shell, and no package manager. The whole system ships as one image of about 400 MB, and a machine with 1 GB of memory can run it.

You manage the machines with kubectl, the same way you manage the workloads. A five-machine cluster, 14 hours after a rolling upgrade:

$ kubectl get clusters
NAME      STATUS   MACHINES   VERSION          NEWEST           AVAILABLE        AGE
homelab   Ready    5/5        2026.08.12-001   2026.08.12-001   2026.08.12-001   18d

$ kubectl get machines
NAME     ROLE       STATUS   UPTIME   ADDRESS        LIKEN            KERNEL                 AGE
node-1   leader     Ready    14h      10.10.0.1/24   2026.08.12-001   7.1.5-070105-generic   18d
node-2   leader     Ready    14h      10.10.0.2/24   2026.08.12-001   7.1.5-070105-generic   18d
node-3   leader     Ready    13h      10.10.0.3/24   2026.08.12-001   7.1.5-070105-generic   18d
node-4   follower   Ready    13h      10.10.0.4/24   2026.08.12-001   7.1.5-070105-generic   18d
node-5   follower   Ready    13h      10.10.0.5/24   2026.08.12-001   7.1.5-070105-generic   18d

Each machine also reports the hardware it found, in its status. Ask with the same tools you already use:

$ kubectl get machine node-4 -o json \
    | jq '.status.hardware | {cpus, memoryBytes, disks: [.blockDevices[].model]}'
{
  "cpus": 4,
  "memoryBytes": 16512733184,
  "disks": [
    "Samsung SSD 970 EVO Plus 500GB",
    "WDC WD40EFRX-68N32N0"
  ]
}

The project is one repository. It contains a Go init written for this project, the Linux kernel and k3s from their upstream releases, and the build that assembles them into a bootable image. Read the repository to see what your machine runs.

Releases are published at releases.liken.sh. Upgrades come straight from the channel: you catalog a release and set the version, and the machines reboot into it one turn at a time.

The manual tells you how to run your own cluster. How liken works explains the model, and Install a cluster gives the steps from a downloaded release to kubectl get nodes.