Ingress with Traefik on K3s

This post is a tutorial on how to expose a website hosted with nginx using the K3s built-in ingress controller, Traefik.

It is based on my last post

Setup Your Own Kubernetes Cluster with K3s— Take 2— k3sup

The result of that was an “empty” cluster without any useful services. In my first post on installing K3s I created an ingress controller based on HAProxy. At that time I was not aware that K3s already includes an ingress controller that is ready to use.

This time, four Kubernetes resources are needed:

ConfigMap
Deployment
Service
Ingress

The ConfigMap is a quick way to make the index.html available to nginx. It is not a clean way of hosting a website and is used only for this tutorial.

First, create the index.html:

<html>
<head><title>Hello World!</title>
 <style>
 html {
  font-size: 500.0%;
 }
 div {
  text-align: center;
 }
 </style>
</head>
<body>
 <div>Hello World!</div>
</body>
</html>

Then create the ConfigMap:

kubectl create configmap test-html --from-file index.html

The remaining manifests are similar to the previous tutorial, except for the volume declaration in the Deployment:

---
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
 name: nginx-ingress
 annotations:
 kubernetes.io/ingress.class: "traefik"
spec:
 rules:
 - http:
  paths:
  - path: /
  backend:
   serviceName: nginx-service
   servicePort: 80

---
apiVersion: v1
kind: Service
metadata:
 name: nginx-service
 labels:
 run: nginx
spec:
 ports:
 - port: 80
  protocol: TCP
 selector:
 app: nginx

---
apiVersion: apps/v1
kind: Deployment
metadata:
 name: nginx-deployment
spec:
 selector:
 matchLabels:
  app: nginx
 replicas: 10
 template:
 metadata:
  labels:
  app: nginx
 spec:
  containers:
  - name: nginx
  image: nginx
  ports:
  - containerPort: 80
  volumeMounts:
  - name: html-volume
   mountPath: /usr/share/nginx/html
  volumes:
  - name: html-volume
  configMap:
   name: test-html

Apply everything with:

kubectl apply -f nginx.yaml

Check the IP where the website can be reached:

$ kubectl get ingress
NAME   CLASS HOSTS ADDRESS  PORTS AGE
nginx-ingress <none> *  12.345.6.789 80  22m

Try it with:

wget 12.345.6.789

This should return the HTML that was added to the ConfigMap at the start of this tutorial.

Ramp Me Up, Scotty!

Ingress with Traefik on K3s

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