coredns 容器在 kubernetes 工作节点中反复重启

Question

我有一个带有 1 个主节点和 2 个工作节点的 kubernetes 集群。我已经安装了法兰绒作为网络插件。工作节点内的 coredns pod 会不断进入 CrashLoopBackOff 状态，然后进入运行状态。有谁知道可能是什么原因。

如果是，请用解决方案指导我

日志：

E0820 08:27:52.824620       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:320: Failed to list *v1.Namespace: Get https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E0820 08:27:52.824913       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:315: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: connect: no route to host
E0820 08:27:54.825587       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:313: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: i/o timeout
E0820 08:27:54.827941       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:320: Failed to list *v1.Namespace: Get https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: connect: no route to host
E0820 08:27:56.827227       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:313: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: connect: no route to host
E0820 08:27:58.831233       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:313: Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/services?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: connect: no route to host
2018/08/20 08:27:59 [INFO] SIGTERM: Shutting down servers then terminating
E0820 08:28:00.839084       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:315: Failed to list *v1.Endpoints: Get https://10.96.0.1:443/api/v1/endpoints?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: connect: no route to host
E0820 08:28:02.847262       1 reflector.go:205] github.com/coredns/coredns/plugin/kubernetes/controller.go:320: Failed to list *v1.Namespace: Get https://10.96.0.1:443/api/v1/namespaces?limit=500&resourceVersion=0: dial tcp 10.96.0.1:443: connect: no route to host