Ashish Kumar Sinha <******@****.***> 1569948788 +0530

	canMigrateCorefile := true

	if corefile == "" || migration.Default("", corefile) {
		// If the Corefile is empty or default, the latest default Corefile will be applied
		if err := apiclient.CreateOrUpdateConfigMap(client, coreDNSConfigMap); err != nil {
			return err
		}
	} else if corefileMigrationRequired {
		// If migration is required, try and migrate the Corefile

			if !strings.EqualFold(migratedConfigMap.Data["Corefile"], tc.expectedCorefileData) {
				t.Fatalf("expected to get %v, but got %v", tc.expectedCorefileData, migratedConfigMap.Data["Corefile"])
			}
		})
	}
}

func createClientAndCoreDNSManifest(t *testing.T, corefile, coreDNSVersion string) *clientsetfake.Clientset {
	client := clientsetfake.NewSimpleClientset()

// that are unsupported for migration.
func checkUnsupportedPlugins(client clientset.Interface) error {
	klog.V(1).Infoln("validating if there are any unsupported CoreDNS plugins in the Corefile")
	_, corefile, currentInstalledCoreDNSversion, err := dns.GetCoreDNSInfo(client)
	if err != nil {
		return err
	}

	currentInstalledCoreDNSversion = strings.TrimLeft(currentInstalledCoreDNSversion, "v")

     "${download_dir}/corefile-tool-${host_arch}" migrate --from "${CURRENT_COREDNS_VERSION}" --to "${NEW_COREDNS_VERSION}" --corefile "${download_dir}/Corefile-old" > "${download_dir}/Corefile"
     "${KUBE_ROOT}/cluster/kubectl.sh" -n kube-system create configmap coredns --from-file "${download_dir}/Corefile" -o yaml --dry-run=client | "${KUBE_ROOT}/cluster/kubectl.sh" apply -f -
  else

          readOnlyRootFilesystem: true
      dnsPolicy: Default
      volumes:
        - name: config-volume
          configMap:
            name: coredns
            items:
            - key: Corefile
              path: Corefile
---
apiVersion: v1
kind: Service
metadata:
  name: kube-dns
  namespace: kube-system
  annotations:
    prometheus.io/port: "9153"
    prometheus.io/scrape: "true"
  labels:

        configMap:
          name: kube-dns
          optional: true
      - name: config-volume
        configMap:
          name: node-local-dns
          items:
            - key: Corefile
              path: Corefile.base
---
# A headless service is a service with a service IP but instead of load-balancing it will return the IPs of our associated Pods.
# We use this to expose metrics to Prometheus.
apiVersion: v1

          readOnlyRootFilesystem: true
      dnsPolicy: Default
      volumes:
        - name: config-volume
          configMap:
            name: coredns
            items:
            - key: Corefile
              path: Corefile
---
apiVersion: v1
kind: Service
metadata:
  name: kube-dns
  namespace: kube-system
  annotations:
    prometheus.io/port: "9153"
    prometheus.io/scrape: "true"
  labels:

          readOnlyRootFilesystem: true
      dnsPolicy: Default
      volumes:
        - name: config-volume
          configMap:
            name: coredns
            items:
            - key: Corefile
              path: Corefile
---
apiVersion: v1
kind: Service
metadata:
  name: kube-dns
  namespace: kube-system
  annotations:
    prometheus.io/port: "9153"
    prometheus.io/scrape: "true"
  labels:

          configMap:
            name: coredns
            items:
            - key: Corefile
              path: Corefile
`

	// CoreDNSConfigMap is the CoreDNS ConfigMap manifest
	CoreDNSConfigMap = `
apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
data:
  Corefile: |
    .:53 {
        errors
        health {
           lameduck 5s
        }