部署CoreDNS

[root@k8s-master1 ~]# kubectl apply -f coredns.yaml

• 查看pod

[root@k8s-master1 ~]# kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
coredns-5ffbfd976d-9wfl7 1/1 Running 1 14h
kube-flannel-ds-amd64-dk64c 1/1 Running 1 14h
kube-flannel-ds-amd64-fkf8q 1/1 Running 8 22m
kube-flannel-ds-amd64-jlb8n 1/1 Running 5 7m31s
kube-flannel-ds-amd64-zxtx2 1/1 Running 1 14h

kubectl run -it --rm dns-test --image=busybox:1.28.4 sh 
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes
Server: 10.0.0.2
Address 1: 10.0.0.2 kube-dns.kube-system.svc.cluster.local
Name: kubernetes
Address 1: 10.0.0.1 kubernetes.default.svc.cluster.local