k8s修改集群coredns

修改coredns 新增加dns 内容
$ kubectl get cm coredns  -n kube-system   -o yaml
apiVersion: v1
data:
  Corefile: |
    .:53 {
        errors
        health
        hosts /etc/coredns/Hosts {
          fallthrough
        }
        kubernetes cluster.local in-addr.arpa ip6.arpa {
           pods insecure
           upstream
           fallthrough in-addr.arpa ip6.arpa
        }
        prometheus :9153
        forward . /etc/resolv.conf
        cache 30
        loop
        reload
        loadbalance
    }
  Hosts: |
    172.24.119.223 news-graphql.xy.huijitrans.com
    172.24.119.223 tgbus-live.xy.huijitrans.com
    172.24.119.223 tgbus-comment.xy.huijitrans.com
    172.24.119.223 tgbus-user.xy.huijitrans.com
    172.24.119.223 graphql.xy.huijitrans.com
    172.24.119.223 tgbus-api.xy.huijitrans.com
    172.24.119.101 k8s-master01.gdfsxxds.rjyun  master01
    172.24.119.102 k8s-master02.gdfsxxds.rjyun  master02
    172.24.119.103 k8s-master03.gdfsxxds.rjyun  master03
    172.24.119.223 k8s-node01.gdfsxxds.rjyun    node01
    172.24.119.224 k8s-node02.gdfsxxds.rjyun    node02
    172.24.119.225 k8s-node03.gdfsxxds.rjyun    node03
    172.24.119.226 k8s-node04.gdfsxxds.rjyun    node04
    172.24.119.252 k8s-harbor01 k8s-harbor01.gdfsxxds.rjyun
    192.168.8.11 mysql-178-fs189
kind: ConfigMap
metadata:
  creationTimestamp: "2019-08-20T04:48:50Z"
  name: coredns
  namespace: kube-system
  resourceVersion: "56953316"
  selfLink: /api/v1/namespaces/kube-system/configmaps/coredns
  uid: cd9f9802-c305-11e9-8099-b8ca3a60e5c8

2. 修改 deployment coredns

 kubectl edit  deployment  coredns  -n kube-system
      volumes:
      - configMap:
          defaultMode: 420
          items:
          - key: Corefile
            path: Corefile
          - key: Hosts    新增加 hosts 配置内容
            path: Hosts
          name: coredns
        name: config-volume

3. coredns pod 会自动重新部署
$ kubectl get pod -n kube-system  |grep dns
coredns-c7b458cf-spkv7                                1/1     Running   0          6m15s
coredns-c7b458cf-wpjjq                                1/1     Running   0          6m15s

原文地址：https://www.cnblogs.com/lixinliang/p/12217319.html