Testing the Setup¶

Now that all components are in place, let's validate the full end-to-end setup by deploying a simple nginx pod exposed via a LoadBalancer service. If MetalLB assigns an external IP and the pod is reachable, your HA cluster is working correctly.

Step 1 — Create the Test Manifest¶

Create a file named nginx-svc.yaml:

nginx-svc.yaml

apiVersion: v1
kind: Service
metadata:
  name: nginx-service
spec:
  type: LoadBalancer
  selector:
    app: nginx
  ports:
  - port: 80
    targetPort: 80
---
apiVersion: v1
kind: Pod
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  containers:
  - name: nginx
    image: nginx
    ports:
    - containerPort: 80

Step 2 — Apply the Manifest¶

sudo kubectl apply -f nginx-svc.yaml

Step 3 — Check the Service¶

sudo kubectl get svc -o wide

Expected output (when MetalLB assigns an IP):

NAME            TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)        AGE
nginx-service   LoadBalancer   10.43.x.x       192.168.0.170    80:3xxxx/TCP   30s

It's working!

If you see an EXTERNAL-IP from your MetalLB pool (e.g. 192.168.0.170), your cluster is fully operational. Try visiting http://192.168.0.170 from any device on your network — you should see the default Nginx welcome page.

Troubleshooting¶

Issue	Possible Cause	Fix
`EXTERNAL-IP` is `<pending>`	MetalLB not configured or pod not ready	Check `kubectl get pods -n metallb-system`
Cannot reach the IP from browser	IP conflict or firewall	Verify the IP range is free; check `iptables` rules
Pod in `Pending` state	No worker nodes schedulable	Check `kubectl get nodes` — workers must be `Ready`

Cleanup¶

To remove the test resources:

sudo kubectl delete -f nginx-svc.yaml

What's next?

Your HA k3s cluster is ready. You can now deploy real workloads using Helm charts, Kustomize, or plain manifests. All LoadBalancer services will automatically receive IPs from your MetalLB pool.