向Kubernetes集群域名服务器中插入自定义的解析记录-coredns
注意：从Kubenretes 1.14开始，集群内部的域名服务器默认换成了
coredns
找到kube-system命名空间的名称为coredns的configmap：
» kubectl get configmap coredns -n kube-system yjzeng@yjzeng-ubuntu
NAME DATA AGE
coredns 1 9d
------------------------------------------------------------------------------------------------------------------------------------------
~ »
编辑这个configmap:
~ » kubectl edit configmap coredns -n kube-system
编辑为以下内容(添加了hosts块)：
apiVersion: v1
data:
Corefile: |
.:53 {
errors
health
kubernetes cluster.local in-addr.arpa ip6.arpa {
pods insecure
upstream
fallthrough in-addr.arpa ip6.arpa
ttl 30
}
hosts {
10.0.0.22 cos6-data1.test.alltest.com
10.0.0.23 cos6-data2.test.alltest.com
10.0.0.24 cos6-data3.test.alltest.com
10.0.0.25 cos6-data4.test.alltest.com
10.0.0.26 cos6-data5.test.alltest.com
10.0.0.41 cos6-datanode6.test.alltest.com
10.0.0.42 cos6-datanode7.test.alltest.com
10.0.0.43 cos6-datanode8.test.alltest.com
10.0.0.44 cos6-datanode9.test.alltest.com
}
prometheus :9153
forward . "/etc/resolv.conf"
cache 30
loop
reload
loadbalance
}
kind: ConfigMap
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"v1","data":{"Corefile":".:53 {\n errors\n health\n kubernetes cluster.local in-addr.arpa ip6.arpa {\n pods insecure\n upstream\n fallthrough in-addr.arpa ip6.arpa\n ttl 30\n }\n prometheus :9153\n forward . \"/etc/resolv.conf\"\n cache 30\n loop\n reload\n loadbalance\n}\n"},"kind":"ConfigMap","metadata":{"annotations":{},"labels":{"addonmanager.kubernetes.io/mode":"EnsureExists"},"name":"coredns","namespace":"kube-system"}}
creationTimestamp: "2019-08-19T09:14:15Z"
labels:
addonmanager.kubernetes.io/mode: EnsureExists
name: coredns
namespace: kube-system
resourceVersion: "3231349"
selfLink: /api/v1/namespaces/kube-system/configmaps/coredns
uid: b791c47f-c261-11e9-b426-525400116042
重启coredns：
~ » kubectl scale deployment coredns -n kube-system --replicas=0
deployment.extensions/coredns scaled
~ » kubectl scale deployment coredns -n kube-system --replicas=2 yjzeng@yjzeng-ubuntu
deployment.extensions/coredns scaled
测试，进入任意一个具有ping命令的pod中，ping自己插入的域名，能通就说明已经生效了。
