Kubernetes V1.11.0 HA群集CoreDNS PODS未出现

Question

我正在尝试在Centos 7服务器中创建Kubernetes V1.11.0 HA集群。 我在主机上禁用了IPV6。

https://kubernetes.io/docs/setup/independent/high-availability/

根据这些步骤，添加了所有三个主服务器，coreDNS POD不会出现，它会将日志记录在/ var / log / messages文件中的错误以下。

kubectl get pods -n kube-system
NAME                                READY     STATUS              RESTARTS   AGE
coredns-78fcdf6894-8t7bt            0/1       ContainerCreating   0          53m
coredns-78fcdf6894-plmll            0/1       ContainerCreating   0          53m

错误信息：

Jul 17 10:09:28 master03 kubelet: E0717 10:09:28.531244   10041 remote_runtime.go:92] RunPodSandbox from runtime service failed: rpc error: code = Unknown desc = [failed to set up sandbox container "8cf72126bd4ea7e33806512997d02b51c3f95331701928c52c19d1ddea9d6f9c" network for pod "coredns-78fcdf6894-8t7bt": NetworkPlugin cni failed to set up pod "coredns-78fcdf6894-8t7bt_kube-system" network: open /proc/sys/net/ipv6/conf/eth0/accept_dad: no such file or directory, failed to clean up sandbox container "8cf72126bd4ea7e33806512997d02b51c3f95331701928c52c19d1ddea9d6f9c" network for pod "coredns-78fcdf6894-8t7bt": NetworkPlugin cni failed to teardown pod "coredns-78fcdf6894-8t7bt_kube-system" network: failed to get IP addresses for "eth0": <nil>]
Jul 17 10:09:28 master03 kubelet: E0717 10:09:28.531286   10041 kuberuntime_sandbox.go:56] CreatePodSandbox for pod "coredns-78fcdf6894-8t7bt_kube-system(7caa3f29-89c3-11e8-aa0f-00505693ca30)" failed: rpc error: code = Unknown desc = [failed to set up sandbox container "8cf72126bd4ea7e33806512997d02b51c3f95331701928c52c19d1ddea9d6f9c" network for pod "coredns-78fcdf6894-8t7bt": NetworkPlugin cni failed to set up pod "coredns-78fcdf6894-8t7bt_kube-system" network: open /proc/sys/net/ipv6/conf/eth0/accept_dad: no such file or directory, failed to clean up sandbox container "8cf72126bd4ea7e33806512997d02b51c3f95331701928c52c19d1ddea9d6f9c" network for pod "coredns-78fcdf6894-8t7bt": NetworkPlugin cni failed to teardown pod "coredns-78fcdf6894-8t7bt_kube-system" network: failed to get IP addresses for "eth0": <nil>]
Jul 17 10:09:28 master03 kubelet: E0717 10:09:28.531298   10041 kuberuntime_manager.go:646] createPodSandbox for pod "coredns-78fcdf6894-8t7bt_kube-system(7caa3f29-89c3-11e8-aa0f-00505693ca30)" failed: rpc error: code = Unknown desc = [failed to set up sandbox container "8cf72126bd4ea7e33806512997d02b51c3f95331701928c52c19d1ddea9d6f9c" network for pod "coredns-78fcdf6894-8t7bt": NetworkPlugin cni failed to set up pod "coredns-78fcdf6894-8t7bt_kube-system" network: open /proc/sys/net/ipv6/conf/eth0/accept_dad: no such file or directory, failed to clean up sandbox container "8cf72126bd4ea7e33806512997d02b51c3f95331701928c52c19d1ddea9d6f9c" network for pod "coredns-78fcdf6894-8t7bt": NetworkPlugin cni failed to teardown pod "coredns-78fcdf6894-8t7bt_kube-system" network: failed to get IP addresses for "eth0": <nil>]
Jul 17 10:09:28 master03 kubelet: E0717 10:09:28.531358   10041 pod_workers.go:186] Error syncing pod 7caa3f29-89c3-11e8-aa0f-00505693ca30 ("coredns-78fcdf6894-8t7bt_kube-system(7caa3f29-89c3-11e8-aa0f-00505693ca30)"), skipping: failed to "CreatePodSandbox" for "coredns-78fcdf6894-8t7bt_kube-system(7caa3f29-89c3-11e8-aa0f-00505693ca30)" with CreatePodSandboxError: "CreatePodSandbox for pod \"coredns-78fcdf6894-8t7bt_kube-system(7caa3f29-89c3-11e8-aa0f-00505693ca30)\" failed: rpc error: code = Unknown desc = [failed to set up sandbox container \"8cf72126bd4ea7e33806512997d02b51c3f95331701928c52c19d1ddea9d6f9c\" network for pod \"coredns-78fcdf6894-8t7bt\": NetworkPlugin cni failed to set up pod \"coredns-78fcdf6894-8t7bt_kube-system\" network: open /proc/sys/net/ipv6/conf/eth0/accept_dad: no such file or directory, failed to clean up sandbox container \"8cf72126bd4ea7e33806512997d02b51c3f95331701928c52c19d1ddea9d6f9c\" network for pod \"coredns-78fcdf6894-8t7bt\": NetworkPlugin cni failed to teardown pod \"coredns-78fcdf6894-8t7bt_kube-system\" network: failed to get IP addresses for \"eth0\": <nil>]"
Jul 17 10:09:28 master03 kubelet: W0717 10:09:28.636173   10041 cni.go:243] CNI failed to retrieve network namespace path: cannot find network namespace for the terminated container "88183d8a24dcafca5b04e3a6454e83aca1417a6934f50cd52b3e6fffbae4f272"
Jul 17 10:09:28 master03 kernel: XFS (dm-18): Mounting V4 Filesystem

如何解决此错误消息并带来coreDNS POD？

谢谢

Answer 1

Coreos Github上有一个问题可以准确描述您的情况。 解决该问题的建议是：

squeed ：您使用的是旧版本的CNI，该版本在禁用ipv6的系统上不起作用。 请重新启用ipv6或升级CNI。

关于CNI Github的相关问题，他还提到：

squeed ：正如我已经解释的，此问题已修复6个月。 请升级您的CNI插件。

耶隆内克评论说：

这是您的部署软件提供商的问题，在您的情况下可能是https://github.com/kubernetes/kubeadm

但是，如果出于某些原因需要关闭ipv6，则可以使用kubeadm使用插件 KubeDNS而不是CoreDNS安装集群：

kubeadm初始化--pod-network-cidr = 192.168.0.0 / 16 --feature-gates = CoreDNS = false

或者，您可以删除CoreDNS部署和服务，然后应用KubeDNS yaml，应将其生成或调整为实际的群集配置。

这是deployAddons.sh文件中的函数，用于部署kube-dns插件：

function deploy_dns {
  echo "Deploying DNS on Kubernetes"
  cp "${KUBE_ROOT}/cluster/addons/dns/kube-dns/kube-dns.yaml.sed" kube-dns.yaml
  sed -i -e "s/\\\$DNS_DOMAIN/${DNS_DOMAIN}/g" kube-dns.yaml
  sed -i -e "s/\\\$DNS_SERVER_IP/${DNS_SERVER_IP}/g" kube-dns.yaml

  KUBEDNS=`eval "${KUBECTL} get services --namespace=kube-system | grep kube-dns | cat"`

  if [ ! "$KUBEDNS" ]; then
    # use kubectl to create kube-dns addon
    ${KUBECTL} --namespace=kube-system create -f kube-dns.yaml

    echo "Kube-dns addon is successfully deployed."
  else
    echo "Kube-dns addon is already deployed. Skipping."
  fi

  echo
}

Answer 2

我必须为我的CoreDNS pod启用IPv6才能运行。

这是我遵循的步骤：

https://www.thegeekdiary.com/how-to-enable-ipv6-on-centos-rhel-7/

编辑/etc/default/grub并将以下行的内核参数ipv6.disable的值从1更改为0：

# grub2-mkconfig -o /boot/grub2/grub.cfg

# shutdown -r now

Answer 3

我在没有启用IPv6的情况下解决了问题（在https://www.facebook.com/groups/k8skr的帮助下）

因此，原因是，Ubuntu的默认Kubernetes CNI为0.6.0。 但是问题已通过Kubernetes CNI 0.7.0修复，因此您可以通过从以下站点下载进行更新并将bin文件替换为/opt/cni/bin/

https://github.com/containernetworking/plugins/releases/tag/v0.7.1

至少，它对我有用:)

Answer 4

我通过这些链接的参考解决了这个问题

检查kubernates故障排除指南和您使用过的网络插件插件

https://kubernetes.io/docs/setup/independent/troubleshooting-kubeadm/#coredns-or-kube-dns-is-stuck-in-the-pending-state

https://kubernetes.io/docs/concepts/cluster-administration/addons/

并安装以下内容并检查

kubectl get pods -n kube-system