K3S

K3S is a lightweight Kubernetes distribution. It is easy to set up and manage, and it can be deployed on a variety of hardware platforms.

k3sup

k3sup, pronounced ‘ketchup’ is a utility that makes it easy to set up a K3S cluster. It can be used to deploy a cluster on a single node or multiple nodes, and it can be configured to use a variety of cloud providers or on-premises infrastructure.

How did I setup a K3S cluster?

  • For the kubernetes cluster:
    • Deployed 3 Ubuntu Server VMs(22.04.3) with 4 vCPUs and 4GB RAM each
  • On my Ubuntu dekstop
    • Installed k3sup
    • Setup login by certificate to the 3 Ubuntu Server VMs.
    • Enabled passwordless sudo on the 3 Ubuntu Server VMs.
    • Used k3sup to install the k3s cluster
    • Used k3sup to join worker nodes to the k3s cluster

Step by step

  1. Create 3 Ubuntu Server VMs
  2. Configure login using certificates, Refer Login using certificates
  3. Configure paswordless sudo. Refer No more password prompts when using sudo
  4. Install k3sup
curl -sLSf https://get.k3sup.dev | sh

sudo install -m k3sup /usr/local/bin/
  1. Install kubectl
curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"

sudo install -m kubectl /usr/local/bin
  1. Make a note of the k3s release you want to use for your Kubernetes Cluster from here: https://github.com/k3s-io/k3s/releases
    • I used version v1.26.9+k3s1
  2. You will need the following information to use as arguments for k3sup.
Hostname or IP Address of the 3 Ubuntu Server VMs you setup
User account for which you enabled login using certificates and passwordless sudo
K3S version from https://github.com/k3s-io/k3s/releases
  1. Deploy kubernetes to the first node. The first node will be the master node. You can configure additional master nodes or worker nodes using k3sup join later.
k3sup install --host k3s01.zion --cluster --k3s-version v1.26.9+k3s1 --user jahnin

If you get the following error, make sure you have setup passwordless sudo. Refer No more password prompts when using sudo

sudo: a terminal is required to read the password; either use the -S option to read from standard input or configure an askpass helper
Error: error received processing command: Process exited with status 1
  1. After cluster installation, test your cluster
export KUBECONFIG=/home/jahnin/kubeconfig
kubectl config use-context default
kubectl get node -o wide
  1. Add the other 2 VMs as worker nodes
k3sup join --host k3s02.zion --server-host k3s01.zion --user jahnin --k3s-version v1.26.9+k3s1
k3sup join --host k3s03.zion --server-host k3s01.zion --user jahnin --k3s-version v1.26.9+k3s1
  1. After installation, check the nodes in your cluster
kubectl get node -o wide

Clean Up

If for whatever reason you need to clean up any of the nodes, use the following command:

/usr/local/bin/k3s-uninstall.sh