kubeadm重新拉取集群的方式

由于本地的虚拟机linux的宿主机是笔记本电脑，经常睡眠，重新打开电脑就会有kubernetes 集群就会有各种各样的问题。
哎，kubeadm拉的集群就是经常这样.
如果只是实验环境，那么重新拉取就好了。

step1 清空k8s环境

master, node， 所有的节点，都要做这个动作。

kubeadm reset 
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step2 初始化master节点

我这里运行了init.sh文件，代码很简单，就是将自生成的ca证书通过ssh拉取到本地，init.sh脚本如下

[root@master01 lifalin]# cat init.sh 
#!/bin/bash

mkdir -p /etc/kubernetes/pki
cd /etc/kubernetes/pki

sshpass -p "XX" scp centos:/opt/certs/ca.pem ca.crt
sshpass -p "XX" scp centos:/opt/certs/ca-key.pem ca.key

kubeadm init \
--apiserver-advertise-address=192.168.5.140 \
--image-repository registry.aliyuncs.com/google_containers \
--service-cidr=10.96.0.0/16 \
--pod-network-cidr=10.244.0.0/16 \
--upload-certs

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init.sh运行结果如下：

[root@master01 lifalin]# ./init.sh
I0919 23:26:21.956094   67084 version.go:255] remote version is much newer: v1.25.1; falling back to: stable-1.24
[init] Using Kubernetes version: v1.24.5
[preflight] Running pre-flight checks
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'


[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local master01] and IPs [10.96.0.1 192.168.5.140]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [localhost master01] and IPs [192.168.5.140 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [localhost master01] and IPs [192.168.5.140 127.0.0.1 ::1]
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Starting the kubelet
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s
[apiclient] All control plane components are healthy after 18.660811 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config" in namespace kube-system with the configuration for the kubelets in the cluster
[upload-certs] Storing the certificates in Secret "kubeadm-certs" in the "kube-system" Namespace
[upload-certs] Using certificate key:
0c2cf44270229a6ce264148c7ae48c0ede11b0d0a9f1dfc32a3193db69318bd9
[mark-control-plane] Marking the node master01 as control-plane by adding the labels: [node-role.kubernetes.io/control-plane node.kubernetes.io/exclude-from-external-load-balancers]
[mark-control-plane] Marking the node master01 as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule node-role.kubernetes.io/control-plane:NoSchedule]
[bootstrap-token] Using token: wzqadx.om71wkwoxqohqgds
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] Configured RBAC rules to allow Node Bootstrap tokens to get nodes
[bootstrap-token] Configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstrap-token] Configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstrap-token] Configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[addons] Applied essential addon: CoreDNS
[addons] Applied essential addon: kube-proxy

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/

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

kubeadm join 192.168.5.140:6443 --token wzqadx.om71wkwoxqohqgds \
	--discovery-token-ca-cert-hash sha256:d84f2217d0ec03008578a82f68ce3947fe5dac23c21fbe63f22c82f2ed38c973 
[root@master01 lifalin]# 
[root@master01 lifalin]# kubectl get nodes
Unable to connect to the server: x509: certificate signed by unknown authority (possibly because of "crypto/rsa: verification error" while trying to verify candidate authority certificate "kubernetes")

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到此表示master 节点初始化成功，
此处kubectl get nodes报了个错，是因为 kube.config文件没有配置正确,显示证书签发权限有问题，
所以要看好啊，运行上边提示的我们要配置什么:

[root@master01 lifalin]#   mkdir -p $HOME/.kube
[root@master01 lifalin]#   sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
[root@master01 lifalin]#   sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
cp: overwrite ‘/root/.kube/config’? y
[root@master01 lifalin]# kubectl get nodes
NAME       STATUS     ROLES           AGE     VERSION
master01   NotReady   control-plane   5m17s   v1.24.3

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再次kubectl get nodes发现没有问题了

step3 初始化node节点

剩下的就是搞node节点了,同样先

kubeadm reset 
kubeadm join 192.168.5.140:6443 --token wzqadx.om71wkwoxqohqgds \
	--discovery-token-ca-cert-hash sha256:d84f2217d0ec03008578a82f68ce3947fe5dac23c21fbe63f22c82f2ed38c973 

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