About CoreDNS CoreDNS is a flexible, extensible DNS server that can serve as the Kubernetes cluster DNS. Like Kubernetes, the CoreDNS project is hosted by the CNCF. You can use CoreDNS instead of kube-dns in your cluster by replacing kube-dns in an existing deployment, or by using tools like kubeadm that will deploy and upgrade the cluster for you.
[root@elasticsearch01 coredns]# ./deploy.sh -h usage: ./deploy.sh [ -r REVERSE-CIDR ] [ -i DNS-IP ] [ -d CLUSTER-DOMAIN ] [ -t YAML-TEMPLATE ] -r : Define a reverse zone for the given CIDR. You may specifcy this option more than once to add multiple reverse zones. If no reverse CIDRs are defined, then the default is to handle all reverse zones (i.e. in-addr.arpa and ip6.arpa) -i : Specify the cluster DNS IP address. If not specificed, the IP address of the existing "kube-dns" service is used, if present. -s : Skips the translation of kube-dns configmap to the corresponding CoreDNS Corefile configuration. [root@elasticsearch01 coredns]# ./deploy.sh -s -r 10.254.0.0/16 -i 10.254.0.10 -d cluster.local > coredns.yaml [root@elasticsearch01 coredns]# ls coredns.yaml coredns.yaml.sed deploy.sh
[root@elasticsearch01 coredns]# kubectl create -f coredns.yaml serviceaccount/coredns created clusterrole.rbac.authorization.k8s.io/system:coredns created clusterrolebinding.rbac.authorization.k8s.io/system:coredns created configmap/coredns created deployment.extensions/coredns created service/kube-dns created