四，从节点安装Docker，kubeadm，kubelet，kubectl

安装过程

前面9步和主节点操作流程相同

1，安装基本软件包

yum install wget net‐tools vim bash‐comp* ‐y

2，设置主机名，管理节点设置主机名为master

hostnamectl set-hostname master
su root

3，配置 Master 和 work 节点的域名

vim /etc/hosts

192.168.1.50 master
192.168.1.51 node1
192.168.1.52 node2

4，关闭 防火墙

systemctl stop firewalld
systemctl disable firewalld

5，关闭 SeLinux

setenforce 0
sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config

6，关闭 swap

swapoff -a
yes | cp /etc/fstab /etc/fstab_bak
cat /etc/fstab_bak |grep -v swap > /etc/fstab

7，配置Docker, K8S的阿里云yum源

cat >>/etc/yum.repos.d/kubernetes.repo <<EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo

yum clean all

yum repolist

8，安装并启动 docker

yum install -y docker-ce.x86_64 docker-ce-cli.x86_64 containerd.io.x86_64

mkdir /etc/docker

cat > /etc/docker/daemon.json <<EOF
{
  "registry-mirrors": ["https://registry.cn-hangzhou.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"]
}
EOF

9，编辑/usr/lib/systemd/system/docker.service

vi /usr/lib/systemd/system/docker.service

ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock --exec-opt native.cgroupdriver=systemd

# Restart Docker
systemctl daemon-reload
systemctl enable docker
systemctl restart docker

此时查看 docker info，可以看到默认 Cgroup Driver为 systemd

卸载旧版本

yum remove -y kubelet kubeadm kubectl

安装kubelet、kubeadm、kubectl

yum install -y kubeadm-1.19.3-0 kubectl-1.19.3-0  kubelet-1.19.3-0

重启 docker，并启动 kubelet

systemctl enable kubelet && systemctl start kubelet

将桥接的IPv4流量传递到iptables的链

echo "1" >/proc/sys/net/bridge/bridge-nf-call-iptables
vi /etc/sysctl.d/k8s.conf 
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1 

10，kubadm join 加入集群

这里的token是主节点初始化的时候记录的token,忘记的话需要重新去主节点生成token

kubeadm join 192.168.1.50:6443 --token 9uomuo.5trla2410rvc4yum --discovery-token-ca-cert-hash sha256:e817908582b98d16e92dabecb1d413691676024a5a2e7ba04ed20bd354b0c7a8

默认token的有效期为24小时，当过期之后，该token就不可用了。解决方法如下：重新生成新的token，在master端执行

kubeadm token create --print-join-command

执行完之后回到主节点

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