新增域名

[root@rancher-k3s02 ~]# kubectl -n kube-system describe cm coredns
.....
====
Corefile:
----
.:53 {
    errors
    health
    ready
    kubernetes cluster.local in-addr.arpa ip6.arpa {
      pods insecure
      upstream
      fallthrough in-addr.arpa ip6.arpa
    }
    hosts /etc/coredns/NodeHosts {
      reload 1s
      fallthrough
    }
    prometheus :9153
    forward . /etc/resolv.conf
    cache 30
    loop
    reload
    loadbalance
}

NodeHosts:
----
172.16.3.217 rancher-k3s01
172.16.3.218 rancher-k3s02
ip FQDN
....