coredns 崩溃并出现错误 "Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/****: dial tcp 10.96.0.1:443: connect: no route to host"
coredns crashes with error "Failed to list *v1.Service: Get https://10.96.0.1:443/api/v1/****: dial tcp 10.96.0.1:443: connect: no route to host"
CoreDNS pod 不是 运行。请找到以下状态。
kubectl get po --all-namespaces -o wide | grep -i coredns
kube-system coredns-6955765f44-8qhkr 1/1 Running 0 24m 10.244.0.59 k8s-master <none> <none>
kube-system coredns-6955765f44-lpmjk 0/1 Running 0 24m 10.244.1.43 k8s-worker-node-1 <none> <none>
请在下面找到 pod 的日志。
kubectl logs coredns-6955765f44-lpmjk -n kube-system
E0420 03:43:03.855622 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
E0420 03:43:03.855622 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
E0420 03:43:03.855622 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
E0420 03:43:03.855622 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
E0420 03:43:05.859525 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
E0420 03:43:05.859525 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
要解决 CoreDNS no route to host 问题 pods 你必须通过 运行:
刷新 iptables
systemctl stop kubelet
systemctl stop docker
iptables --flush
iptables -tnat --flush
systemctl start kubelet
systemctl start docker
另请注意，flannel 已从 kubeadm documentation 中的 CNI 列表中删除：
The reason for that is that Cluster Lifecycle have been
getting a number of issues related to flannel (either in kubeadm or
kops tickets) and we don't have good answers for the users as the
project is not actively maintained.
- Add note that issues for CNI should be logged in the respective issue
trackers and that Calico is the only CNI we e2e test kubeadm against.
因此推荐的方法也将转移到 Calico CNI。
我在使用 K8s 1.19.7 和 flannel 时没有任何错误，当我升级到 1.21.1 时它开始显示上述错误并且以下修复对我有效
firewall-cmd --permanent --zone=trusted --add-source=10.244.0.0/16
firewall-cmd --reload
CoreDNS pod 不是 运行。请找到以下状态。
kubectl get po --all-namespaces -o wide | grep -i coredns
kube-system coredns-6955765f44-8qhkr 1/1 Running 0 24m 10.244.0.59 k8s-master <none> <none>
kube-system coredns-6955765f44-lpmjk 0/1 Running 0 24m 10.244.1.43 k8s-worker-node-1 <none> <none>
请在下面找到 pod 的日志。
kubectl logs coredns-6955765f44-lpmjk -n kube-system
E0420 03:43:03.855622 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
E0420 03:43:03.855622 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
E0420 03:43:03.855622 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
E0420 03:43:03.855622 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
E0420 03:43:05.859525 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
E0420 03:43:05.859525 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190620085101-78d2af792bab/tools/cache/reflector.go:98: 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
要解决 CoreDNS no route to host 问题 pods 你必须通过 运行:
systemctl stop kubelet
systemctl stop docker
iptables --flush
iptables -tnat --flush
systemctl start kubelet
systemctl start docker
另请注意，flannel 已从 kubeadm documentation 中的 CNI 列表中删除：
The reason for that is that Cluster Lifecycle have been getting a number of issues related to flannel (either in kubeadm or kops tickets) and we don't have good answers for the users as the project is not actively maintained. - Add note that issues for CNI should be logged in the respective issue trackers and that Calico is the only CNI we e2e test kubeadm against.
因此推荐的方法也将转移到 Calico CNI。
我在使用 K8s 1.19.7 和 flannel 时没有任何错误，当我升级到 1.21.1 时它开始显示上述错误并且以下修复对我有效
firewall-cmd --permanent --zone=trusted --add-source=10.244.0.0/16
firewall-cmd --reload