coredns不断重启， [FATAL] plugin loop

1 coredns不断重启查看日志：
[root@master1 ~]# kubectl logs coredns-5dc5b997f9-2762d -n kube-system
.:53
2018/12/05 02:43:44 [INFO] CoreDNS-1.2.2
2018/12/05 02:43:44 [INFO] linux/amd64, go1.11, eb51e8b
CoreDNS-1.2.2
linux/amd64, go1.11, eb51e8b
2018/12/05 02:43:44 [INFO] plugin/reload: Running configuration MD5 = bd588fad58d911f8ad3f69bf92f5e413
2018/12/05 02:43:50 [FATAL] plugin/loop: Seen “HINFO IN 2752735584824140577.5817901967803382952.” more than twice, loop detected

2 通过查询得知，删除configmap中loop
kubectl edit cm coredns -n kube-system
删除 ，loop保存退出
重启启动，coredns （删除pod）
https://stackoverflow.com/questions/52645473/coredns-fails-to-run-in-kubernetes-cluster