# Deploying the DNS Cluster Add-on In this lab you will deploy the [DNS add-on](https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/) which provides DNS based service discovery to applications running inside the Kubernetes cluster. ## The DNS Cluster Add-on Deploy the `kube-dns` cluster add-on: ``` kubectl create -f https://storage.googleapis.com/kubernetes-the-hard-way/kube-dns.yaml ``` > output ``` serviceaccount "kube-dns" created configmap "kube-dns" created service "kube-dns" created deployment "kube-dns" created ``` List the pods created by the `kube-dns` deployment: ``` kubectl get pods -l k8s-app=kube-dns -n kube-system ``` > output ``` NAME READY STATUS RESTARTS AGE kube-dns-3097350089-gq015 3/3 Running 0 20s ``` ## Verification Create a `busybox` deployment: ``` kubectl run busybox --image=busybox --command -- sleep 3600 ``` List the pod created by the `busybox` deployment: ``` kubectl get pods -l run=busybox ``` > output ``` NAME READY STATUS RESTARTS AGE busybox-2125412808-mt2vb 1/1 Running 0 15s ``` Retrieve the full name of the `busybox` pod: ``` POD_NAME=$(kubectl get pods -l run=busybox -o jsonpath="{.items[0].metadata.name}") ``` Execute a DNS lookup for the `kubernetes` service inside the `busybox` pod: ``` kubectl exec -ti $POD_NAME -- nslookup kubernetes ``` > output ``` Server: 10.32.0.10 Address 1: 10.32.0.10 kube-dns.kube-system.svc.cluster.local Name: kubernetes Address 1: 10.32.0.1 kubernetes.default.svc.cluster.local ``` Next: [Smoke Test](13-smoke-test.md)