Deploying the DNS Cluster Add-on

In this lab you will deploy the DNS add-on which provides DNS based service discovery, backed by CoreDNS, to applications running inside the Kubernetes cluster.

The DNS Cluster Add-on

Deploy the coredns cluster add-on:

kubectl apply -f


serviceaccount/coredns created created created
configmap/coredns created
deployment.extensions/coredns created
service/kube-dns created

List the pods created by the kube-dns deployment:

kubectl get pods -l k8s-app=kube-dns -n kube-system


NAME                       READY   STATUS    RESTARTS   AGE
coredns-699f8ddd77-94qv9   1/1     Running   0          20s
coredns-699f8ddd77-gtcgb   1/1     Running   0          20s


Create a busybox deployment:

kubectl run busybox --image=busybox:1.28 --command -- sleep 3600

List the pod created by the busybox deployment:

kubectl get pods -l run=busybox


NAME                      READY   STATUS    RESTARTS   AGE
busybox-bd8fb7cbd-vflm9   1/1     Running   0          10s

Retrieve the full name of the busybox pod:

POD_NAME=$(kubectl get pods -l run=busybox -o jsonpath="{.items[0]}")

Execute a DNS lookup for the kubernetes service inside the busybox pod:

kubectl exec -ti $POD_NAME -- nslookup kubernetes


Address 1: kube-dns.kube-system.svc.cluster.local

Name:      kubernetes
Address 1: kubernetes.default.svc.cluster.local