Installing K3s Kubernetes Platform

This lab uses k3s as kubernetes platform. It come with traefik as ingress controller. In this guide, traefik will be replaced with NGINX Plus Ingress Controller with App. Protect.

Note

This already available in your lab deployment.

Make sure you’re login to APP node then change install target hostname to app:

$ sudo bash
# hostname app

Make it persistent across restart:

# echo "app" > /etc/hostname

The K3s Install Script

This script will install k3s and remove traefik ingress controller

Note

You can change app inside the while loop to reflect the actual hostname where k3s installed

#!/bin/bash

curl -sfL https://get.k3s.io | INSTALL_K3S_EXEC="--write-kubeconfig-mode 644" sh -s -

# wait until ready
while true;
do
    if [ "$(kubectl get nodes app -o=jsonpath='{.status.conditions[3].status}')" == "True" ]; then
      break;
    fi
    sleep 5;
done

# Based on https://github.com/k3s-io/k3s/issues/1160#issuecomment-1133559423
# remove k3s default ingress controller
set -x
sudo touch /var/lib/rancher/k3s/server/manifests/traefik.yaml.skip
kubectl -n kube-system delete helmchart traefik traefik-crd
sleep 10

sudo systemctl restart k3s

echo "Done"

Execute the install script:

$ bash k3s.sh

Verify K3s Installation

After script execution finished, verify the cluster:

$ kubectl get nodes

Make sure node status is Ready:

NAME   STATUS   ROLES                  AGE   VERSION
app    Ready    control-plane,master   36h   v1.27.3+k3s1

You also can check if traefik service no longer listed:

$ kubectl get svc -n kube-system
NAME             TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                  AGE
kube-dns         ClusterIP   10.43.0.10      <none>        53/UDP,53/TCP,9153/TCP   41h
metrics-server   ClusterIP   10.43.141.175   <none>        443/TCP                  41h

At this point, k3s is ready.