K8S集群重新初始化--详细过程

在引导k8s集群的过程时可能因为这个或那个的原因导致需要重新引导集群 。

下面整理了我在实际工作中初始化k8s集群的详细过程。

0、当前环境

k8s环境部署总览

ip地址	类型	操作系统	服务配置
192.168.162.31	Master01	Centos7.6	2核CPU 2G内存 20G硬盘
192.168.162.41	node1	Centos7.6	2核CPU 2G内存 20G硬盘
192.168.162.42	node2	Centos7.6	2核CPU 2G内存 20G硬盘

1、master节点

1.1、在master节点执行下面reset命令：

kubeadm reset

//过程会询问是否重置，输入y然后回车

1.2、手动清除配置信息，这一步很关键：

cd ~ 进入根目录

ll -a 查看是否存在.kube文件
rm -rf /root/.kube

systemctl restart docker ## 重启docker 
systemctl restart kubelet ## 重启kubelet

rm -rf /etc/cni/net.d

1.3、重新引导集群

kubeadm init xxxxxx

例如，具体按你的为准：

kubeadm init \
--apiserver-advertise-address=192.168.162.31 \
--control-plane-endpoint=k8s-master01-31 \
--image-repository registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images \
--kubernetes-version v1.20.9 \
--service-cidr=10.96.0.0/16 \
--pod-network-cidr=192.168.0.0/16

初始化master节点成功后，拷贝出关键信息：（注意是你自己的信息）

Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

You can now join any number of control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:

  kubeadm join k8s-master01-31:6443 --token m7xgx0.h8m6si6ws2p0r9n6 \
    --discovery-token-ca-cert-hash sha256:f4d3af365aeabab83cf124e5a84aeb8260ae6c0d54a7f5d87928fab37a519aea \
    --control-plane 

Then you can join any number of worker nodes by running the following on each as root:

kubeadm join k8s-master01-31:6443 --token m7xgx0.h8m6si6ws2p0r9n6 \
    --discovery-token-ca-cert-hash sha256:f4d3af365aeabab83cf124e5a84aeb8260ae6c0d54a7f5d87928fab37a519aea 

1.4、创建配置目录，并复制权限配置文件到用户目录下：

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

1.5 查看集群状态

此时就可以在master节点使用kubectl get node 查看集群状态，如果出现状态为notready

kubectl get node 

查看pod状态

1.6 安装Calico网络插件

curl https://docs.projectcalico.org/manifests/calico.yaml -O ## 或者

curl https://docs.projectcalico.org/v3.20/manifests/calico.yaml -O

kubectl apply -f calico.yaml

2、work节点

2.1、重置工作节点

kubeadm reset
//过程会询问是否重置，输入y然后回车

2.2、手动删除目录

rm -rf /root/.kube
rm -rf /etc/cni/net.d
rm -rf /etc/kubernetes/*

2.3、重新加入集群

kubeadm join xxx #获取该指令可以通过在master节点上执行：kubeadm token create --print-join-command

自己生成的命令：

kubeadm join k8s-master01-31:6443 --token m7xgx0.h8m6si6ws2p0r9n6 \
    --discovery-token-ca-cert-hash sha256:f4d3af365aeabab83cf124e5a84aeb8260ae6c0d54a7f5d87928fab37a519aea

在master节点重新获取token

kubeadm token create --print-join-command

3、检验效果

在master节点查看各个node

kubectl get node

在master节点查看pod状态

kubectl get pod -A