k3s-config

Configuration for managing my local k3s cluster.

Setup

I have it running in an ArchLinux box, and my pacman wrapper of choice is pikaur:

pikaur -S k3s-bin

It'll install a systemd unit file alongside k3s, and I've decided to modify the pre-packaged traefik install, so we'll need to modify this.

sudo systemctl edit --full k3s.service

Modify the ExecStart option to include the --no-deploy traefik flag, save, and close.

Then start k3s:

sudo systemctl start k3s.service

On first boot it will generate a kubeconfig for you. If you have other clusters configured in ~/.kube/config then you'll need to manually merge them. The generated config is written in /etc/rancher/k3s/k3s.yaml.

Otherwise, you can use sudo k3s kubectl as a kubectl replacement.

Next, create local hosts file entries for the cluster by running the helper script in scripts.

• Know the interface you want to bind to (e.g. the name of your wifi card from a command like ip a)
• Create a k3s_hosts file with newline separate hostnames
• Backup /etc/hosts to your $HOME, since there are no guardrails on this script

sudo ./scripts/update_k3s_hosts -i wlp2s0 k3s_hosts

Then install traefik:

kubectl apply -f services/traefik.yaml

If all goes well, you should be able to navigate to traefik.gondolin.k3s, or whatever you changed the base hostname to, and see the traefik dashboard.

Local Storage

There is a "host path provisioner" that uses the host machine's filesystem to store data from PVC claims in the cluster. You can enable it by running:

kc apply -f services/storage-class.yaml

Note you'll have to update the YAML file to put in a host path that is writeable on your system.

Docker Registry

k3s by default runs on containerd instead of docker so getting images running in the cluster isn't quite so straightforward. The publish-local script is a wrapper around docker and k3s/ctr to import images for use inside the cluster, simply pass it the image name and it will build the Dockerfile in the current directory:

./scripts/publish-local my.domain.com/container:latest
kc run -i --tty my-container --image=my.domain.com/container:latest --image-pull-policy=Never -- sh