[Mock2_7] DNS lookup

Create a nginx pod called nginx-resolver using image nginx, expose it internally with a service called nginx-resolver-service. Test that you are able to look up the service and pod names from within the cluster. Use the image: busybox:1.28 for dns lookup. Record results in /root/CKA/nginx.svc and /root/CKA/nginx.pod

Pod: nginx-resolver created

Service DNS Resolution recorded correctly

Pod DNS resolution recorded correctly

---

• Pod: nginx-resolver created

k run nginx-resolver --image=nginx

• Service DNS Resolution recorded correctly

apiVersion: v1
kind: Service
metadata:
  name: nginx-resolver-service
spec:
  selector:
    name: busybox
  clusterIP: None
  ports:
  - name: foo # name is not required for single-port Services
    port: 1234
---
apiVersion: v1
kind: Pod
metadata:
  name: busybox
  labels:
    name: busybox
spec:
  hostname: busybox-1
  subdomain: busybox-subdomain
  containers:
  - image: busybox:1.28
    name: busybox

---

kubectl exec -i -t nginx-resolver -- nslookup kubernetes.default

---

Use the command kubectl run and create a nginx pod and busybox pod. Resolve it, nginx service and its pod name from busybox pod.

To create a pod nginx-resolver and expose it internally:

kubectl run nginx-resolver --image=nginx
kubectl expose pod nginx-resolver --name=nginx-resolver-service --port=80 --target-port=80 --type=ClusterIP

To create a pod test-nslookup. Test that you are able to look up the service and pod names from within the cluster:

kubectl run test-nslookup --image=busybox:1.28 --rm -it --restart=Never -- nslookup nginx-resolver-service
kubectl run test-nslookup --image=busybox:1.28 --rm -it --restart=Never -- nslookup nginx-resolver-service > /root/CKA/nginx.svc

Get the IP of the nginx-resolver pod and replace the dots(.) with hyphon(-) which will be used below.

kubectl get pod nginx-resolver -o wide
kubectl run test-nslookup --image