安装Kubernetes报错：/proc/sys/net/ipv

安装完Kubernetes集群后，想看一下所有pod的运行状态，结果发现有几个pods一直处于ContainerCreating状态，虽然不太了解，但凭个人感觉也发现不太正常。

查看pods状态

$ sudo kubectl get pods --all-namespaces
NAMESPACE     NAME                                    READY   STATUS              RESTARTS   AGE
kube-system   coredns-58d6b7c8d7-m66pf                0/1     ContainerCreating   0          35m
kube-system   coredns-58d6b7c8d7-prngb                0/1     ContainerCreating   0          35m
kube-system   etcd-kube-node1                         1/1     Running             2          34m
kube-system   kube-apiserver-kube-node1               1/1     Running             2          32m
kube-system   kube-controller-manager-kube-node1      1/1     Running             2          35m
kube-system   kube-flannel-ds-amd64-7lblq             1/1     Running             0          29m

查看Pods详情

$ sudo kubectl describe pods coredns-58d6b7c8d7-m66pf --namespace=kube-system

# 省略部分错误信息
Warning  FailedCreatePodSandBox  24m                    kubelet, kube-node2  Failed create pod sandbox: 
rpc error: code = Unknown desc = [failed to set up sandbox container "368d7ee2bcb5bc2dbdec304131ff25746962537956a47360d9ccfd535b21c76a" 
network for pod "kubernetes-dashboard-6dccb458d5-x7xft": 
NetworkPlugin cni failed to set up pod "kubernetes-dashboard-6dccb458d5-x7xft_kube-system" network: 
open /proc/sys/net/ipv6/conf/eth0/accept_dad: no such file or directory,
 failed to clean up sandbox container "368d7ee2bcb5bc2dbdec304131ff25746962537956a47360d9ccfd535b21c76a" network for pod "kubernetes-dashboard-6dccb458d5-x7xft": 
NetworkPlugin cni failed to teardown pod "kubernetes-dashboard-6dccb458d5-x7xft_kube-system" network: 
failed to get IP addresses for "eth0": <nil>]

原因是slave上未启用IPV6

启用IPV6

sudo sed -i 's\ipv6.disable=1\ipv6.disable=0\g' /etc/default/grub
sudo grub2-mkconfig -o /boot/grub2/grub.cfg
sudo reboot