Coredns modifying upstream

coredns Default upstream/forword yes 8.8.8.8, It's easy if you don't modify it crash, You can refer to ：https://kubernetes.io/docs/tasks/administer-cluster/dns-custom-nameservers/.

coredns  The default is as follows ：
apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
data:
  Corefile: | .:53 { errors health { lameduck 5s } ready kubernetes cluster.local in-addr.arpa ip6.arpa { pods insecure fallthrough in-addr.arpa ip6.arpa ttl 30 } prometheus :9153 forward . /etc/resolv.conf cache 30 loop reload loadbalance } 

So if you create it yourself coredns image, You can modify /etc/resolv.conf The contents of the document , Yes, it can be modified configMap, then delete Already exist pod To achieve the purpose of revision .

apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
data:
  Corefile: | .:53 { errors health { lameduck 5s } ready kubernetes cluster.local in-addr.arpa ip6.arpa { pods insecure fallthrough in-addr.arpa ip6.arpa ttl 30 } prometheus :9153 forward . 114.114.114.114 cache 30 loop reload loadbalance }