在三台机器上都执行如下命令操作：

 1、关闭防火墙
 systemctl stop firewalld
 systemctl disable firewalld

 2、关闭 selinux
 sed -i 's/enforceing/disabled/' /etc/selinux/config # 永久关闭
 setenforce 0 # 临时关闭

 3、关闭 swap
 swapoff -a # 临时关闭
 vim /etc/fstab # 永久关闭
 #注释掉swap这行
 # /dev/mapper/centos‐swap swap swap defaults 0 0 
 (sed -ri 's/.*swap.*/#&/' /etc/fstab)

 systemctl reboot #重启生效 可以不用重启
 free ‐m #查看下swap交换区是否都为0，如果都为0则swap关闭成功

 4、给三台机器分别设置主机名
 hostnamectl set-hostname <hostname>
 第一台：k8s‐master
 第二台：k8s‐node1
 第三台：k8s‐node2

 5、在 k8s‐master机器添加hosts，执行如下命令，ip需要修改成你自己机器的ip
cat >> /etc/hosts << EOF
192.168.1.55 k8s‐master
192.168.1.50 k8s‐node1
192.168.1.60 k8s‐node2
EOF

 6、将桥接的IPv4流量传递到iptables
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge‐nf‐call‐ip6tables = 1
net.bridge.bridge‐nf‐call‐iptables = 1
EOF

 sysctl --system # 生效

 7、设置时间同步
 yum install ntpdate ‐y
 ntpdate time.windows.com




 8、添加k8s yum源

cat <<EOF | sudo tee /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
   http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
exclude=kubelet kubeadm kubectl
EOF

配置docker yum源

sudo yum install -y yum-utils
sudo yum-config-manager \
--add-repo \
http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

安装docker 和k8s的版本对应
yum install -y docker-ce-20.10.7 docker-ce-cli-20.10.7  containerd.io-1.4.6
设置启动：systemctl enable docker --now
设置加速器：sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://8gh555t2.mirror.aliyuncs.com"],
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2"
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker


 9、如果之前安装过k8s，先卸载旧版本
 yum remove ‐y kubelet kubeadm kubectl



 10、查看可以安装的版本
 yum list kubelet --showduplicates | sort -r

 11、安装kubelet、kubeadm、kubectl 指定版本，我们使用kubeadm方式安装k8s集群
 sudo yum install -y kubelet-1.20.9 kubeadm-1.20.9 kubectl-1.20.9 --disableexcludes=kubernetes

 12、开机启动kubelet

sudo systemctl enable --now kubelet
 systemctl enable kubelet
 systemctl start kubelet

下载各个机器需要的镜像

sudo tee ./images.sh <<-'EOF'
#!/bin/bash
images=(
kube-apiserver:v1.20.9
kube-proxy:v1.20.9
kube-controller-manager:v1.20.9
kube-scheduler:v1.20.9
coredns:1.7.0
etcd:3.4.13-0
pause:3.2
)
for imageName in ${images[@]} ; do
docker pull registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/$imageName
done
EOF
   
chmod +x ./images.sh && ./images.sh

所有机器添加master域名映射，以下需要修改为自己的

echo "192.168.1.55 cluster-endpoint" >> /etc/hosts

主节点初始化

kubeadm init \
--apiserver-advertise-address=192.168.1.55 \
--control-plane-endpoint=cluster-endpoint \
--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=192.166.0.0/16

拷贝安装成功后的信息

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 cluster-endpoint:6443 --token v356cn.uooob6wel6064x16 \
    --discovery-token-ca-cert-hash sha256:e887b8fb668a3bd5e548fb0c5c9f9ec73556e180c9989862b7c2df501ecb6227 \
    --control-plane 

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

kubeadm join cluster-endpoint:6443 --token v356cn.uooob6wel6064x16 \
    --discovery-token-ca-cert-hash sha256:e887b8fb668a3bd5e548fb0c5c9f9ec73556e180c9989862b7c2df501ecb6227 

如何是root用户需要执行否则 命令kubectl get pods 会报：The connection to the server localhost:8080 was refused - did you specify the right host or port?

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

或者创建非root用户，执行相应的

然后 #查看集群所有节点
kubectl get nodes

运行中的应用在docker里面叫容器，在k8s里面叫Pod

kubectl get pods -A
安装网络组件

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

kubectl apply -f calico.yaml

加入Node节点：

kubeadm join cluster-endpoint:6443 --token v356cn.uooob6wel6064x16 \
    --discovery-token-ca-cert-hash sha256:e887b8fb668a3bd5e548fb0c5c9f9ec73556e180c9989862b7c2df501ecb6227

● 验证集群节点状态
○ kubectl get nodes