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Summary

Ingress and Services

Learn how to expose Kubernetes applications to your network using Services and Ingress controllers in K3s.

By Kevin McAleer,    3 Minutes

Page last updated May 24, 2025

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By default, Kubernetes services are only accessible inside the cluster. To make apps available on your local network or the internet, you’ll need to use Services and optionally an Ingress controller.

K3s includes Traefik as its default ingress controller, which makes this easy to configure.

🌐 What Is a Service?

A Kubernetes Service is an abstraction that exposes a set of pods to other services or users.

Type Use Case
ClusterIP Internal-only (default)
NodePort Exposes app on a fixed port
LoadBalancer Cloud environments (external IP)

🚀 Exposing a Pod with a Service

Let’s say you have a deployment called hello-world (like from Lesson 8). You can expose it:

kubectl expose deployment hello-world --port=80 --type=NodePort

Check the assigned port:

kubectl get svc hello-world

Then open http://<node-ip>:<nodePort> in your browser.

🌍 What Is an Ingress?

Ingress is a more flexible way to expose multiple services using a reverse proxy and host/path routing.

Example:

  • http://pi.local/app1 → nginx app
  • http://pi.local/app2 → another service

K3s ships with Traefik, a built-in Ingress controller.

🧱 Step 1: Define an Ingress Resource

Create a file called hello-ingress.yaml:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: hello-ingress
  annotations:
    traefik.ingress.kubernetes.io/router.entrypoints: web
spec:
  rules:
  - host: hello.local
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: hello-world
            port:
              number: 80

Apply it:

kubectl apply -f hello-ingress.yaml

🛠 Step 2: Update Your Local DNS

On your workstation, edit /etc/hosts:

192.168.1.100 hello.local

Replace 192.168.1.100 with your master node IP.

Now try visiting:

http://hello.local

🧪 Verify Ingress

Check if the Ingress was created:

kubectl get ingress

Check Traefik logs (optional):

kubectl logs -n kube-system -l app=traefik

🔒 Optional: Enable HTTPS with Let’s Encrypt

K3s and Traefik support automated HTTPS with Let’s Encrypt — but you’ll need a real domain and port 80/443 open.

If you’d like to add this, let me know and I can walk you through it.

✅ Summary

You now know how to:

  • Use NodePort to expose services to the LAN
  • Create an Ingress resource with path/host routing
  • Use Traefik, the default Ingress controller in K3s
  • Set up basic DNS for friendly URLs

Next up: Deploying Apps

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