Deploying the DNS Cluster Add-on

In this lab you will deploy the DNS add-on 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

service "kube-dns" created
serviceaccount "kube-dns" created
configmap "kube-dns" created
deployment.extensions "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

Create a dnsutils pod (Not creating a busybox as it has issue#356 with DNS resolution):

kubectl run netutils --image=hiprabhat/netutils:2 --restart=Never -- sleep 3600

Verify that the pod is running:

kubectl get pod netutils

Output:

NAME       READY     STATUS    RESTARTS   AGE
netutils   1/1       Running   0          45s

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

kubectl exec -it netutils -- nslookup kubernetes

output

Server:		10.32.0.10
Address:	10.32.0.10#53

Name:	kubernetes.default.svc.cluster.local
Address: 10.32.0.1