kubernetes 常见问题整理

使用kubectl 命令是报错

报错：

[root@k8s-master ~]# kubectl get pod
The connection to the server localhost: was refused - did you specify the right host or port?

原因： 由于使用kubeadm安装的k8s ,所以需要使用 kubernetes-admin 来运行。

解决方法:  (如果admin.conf没有就从k8s-master上copy一份到当前节点)

[root@k8s-master ~]# export KUBECONFIG=/etc/kubernetes/admin.conf
[root@k8s-master ~]# kubectl get pod
No resources found.
[root@k8s-master ~]# kubectl get node
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    master   46h   v1.14.0
[root@k8s-master ~]#

#也可以编辑 ~/.bash_profile,, 如果使用的是 zsh 那就编辑 ~/.zshrc
添加内容
export KUBECONFIG=/etc/kubernetes/admin.conf
使其生效
source ~/.bash_profile   如果是zsh    source ~/.zshrc

用kubeadm 增加节点的方法：：有时 忘记token 或 token过期，以及查看 --discovery-token-ca-cert-hash 的方法

#查看当前存在的token
[root@k8s-master testnginx]# kubeadm token list
TOKEN                     TTL       EXPIRES                     USAGES                   DESCRIPTION                                                EXTRA GROUPS
uf2c4g.n7ibf1g8gxbkqz2z   22h       --03T15::+:   authentication,signing   The default bootstrap token generated by 'kubeadm init'.   system:bootstrappers:kubeadm:default-node-token

#生成新的token
[root@k8s-master testnginx]# kubeadm token create
hpvhe4.rbapeoum7utj55cr

#再次查看已有的token 发现多了一个
[root@k8s-master testnginx]# kubeadm token list
TOKEN                     TTL       EXPIRES                     USAGES                   DESCRIPTION                                                EXTRA GROUPS
hpvhe4.rbapeoum7utj55cr   23h       --03T16::+:   authentication,signing   <none>                                                     system:bootstrappers:kubeadm:default-node-token
uf2c4g.n7ibf1g8gxbkqz2z   22h       --03T15::+:   authentication,signing   The default bootstrap token generated by 'kubeadm init'.   system:bootstrappers:kubeadm:default-node-token

#查看 --discovery-token-ca-cert-hash 方法
[root@k8s-master testnginx]# openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null |    openssl dgst -sha256 -hex | sed 's/^.* //'
f01892c96cee8d02c373e34bed3a45c8f3f9888fdd19767e706ec09e8fb9c893

#由于我是用来测试 所以删掉这个token
[root@k8s-master testnginx]# kubeadm token delete hpvhe4.rbapeoum7utj55cr
bootstrap token with id "hpvhe4" deleted

#查看token是否删除成功
[root@k8s-master testnginx]# kubeadm token list
TOKEN                     TTL       EXPIRES                     USAGES                   DESCRIPTION                                                EXTRA GROUPS
uf2c4g.n7ibf1g8gxbkqz2z   22h       --03T15::+:   authentication,signing   The default bootstrap token generated by 'kubeadm init'.   system:bootstrappers:kubeadm:default-node-token
[root@k8s-master testnginx]#

node节点反复安装报错

报错: cni.go:259] Error adding network: failed to set bridge addr: "cni0" already has an IP address different from 10.16.2.1/24

解决:在Node上执行如下操作：重置kubernetes服务，重置网络。删除网络配置，link

kubeadm reset
systemctl stop kubelet
systemctl stop docker
rm -rf /var/lib/cni/
rm -rf /var/lib/kubelet/*
rm -rf /etc/cni/
ifconfig cni0 down
ifconfig flannel. down
ifconfig docker0 down
ip link delete cni0
ip link delete flannel.

qingfeng