1. 查看现在已有的节点信息

[root@kub-k8s-master ~]#  kubectl get nodes
NAME             STATUS   ROLES    AGE    VERSION
kub-k8s-master   Ready    master   102m   v1.17.4
kub-k8s-node1    Ready    <none>   96m    v1.17.4
kub-k8s-node2    Ready    <none>   96m    v1.17.4

2. 关闭防火墙和selinux

systemctl stop firewalld && systemctl disable firewalld && sed -i 's/SELINUX=permissive/SELINUX=disabled/' /etc/sysconfig/selinux

3. 关闭交换分区

sed -i 's/.*swap.*/#&/' /etc/fstab

4. 开启路由转发

sysctl -w net.ipv4.ip_forward=1

5. 设置本地解析
   所有节点都添加下

vim /etc/hosts
192.168.230.141   kub-k8s-master
192.168.230.138   kub-k8s-node1
192.168.230.139   kub-k8s-node2
192.168.230.140   kub-k8s-node3   

6. 修改主机名

hostnamectl set-hostname kub-k8s-node3 &&  echo 'kub-k8s-node3'>/etc/hostname

7. 下载docker 并启动
   添加节点的docker版本必须与主节点一致，否则总是NotReady

# yum remove docker \
docker-client \
docker-client-latest \
docker-common \
docker-latest \
docker-latest-logrotate \
docker-logrotate \
docker-selinux \
docker-engine-selinux \
docker-engine
# yum install -y yum-utils device-mapper-persistent-data lvm2 git
# yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

# yum install docker-ce -y

systemctl enable docker && systemctl start docker

8. 拉取组件
   这里需要拉取的组件要与master的版本一致，我们可以kubele --version查看下，其次，国内无法访问"k8s.gcr.io" 我们可以先拉取阿里云的，然后打上k8s.gcr.io标签即可。

已知master是v1.17.4版本的
拉取阿里云镜像
[root@k8s-master ~]# docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.17.4
[root@k8s-master ~]# docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.17.4
[root@k8s-master ~]# docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.17.4
[root@k8s-master ~]# docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.17.4
[root@k8s-master ~]# docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.6.5
[root@k8s-master ~]# docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.4.3-0
[root@k8s-master ~]# docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1

打上 k8s 的标签

[root@k8s-master ~]# docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-controller-manager:v1.17.4 k8s.gcr.io/kube-controller-manager:v1.17.4
[root@k8s-master ~]# docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-proxy:v1.17.4 k8s.gcr.io/kube-proxy:v1.17.4
[root@k8s-master ~]# docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-apiserver:v1.17.4 k8s.gcr.io/kube-apiserver:v1.17.4
[root@k8s-master ~]# docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/kube-scheduler:v1.17.4 k8s.gcr.io/kube-scheduler:v1.17.4
[root@k8s-master ~]# docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.6.5 k8s.gcr.io/coredns:1.6.5
[root@k8s-master ~]# docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/etcd:3.4.3-0 k8s.gcr.io/etcd:3.4.3-0
[root@k8s-master ~]# docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.1 k8s.gcr.io/pause:3.1

9. 安装kubeadm和kubelet

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[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

10. 下载节点组件

yum install -y kubelet-1.17.4-0.x86_64 kubeadm-1.17.4-0.x86_64 kubectl-1.17.4-0.x86_64 ipvsadm

10. 编辑文件添加开机启动

 vim /etc/rc.local 
 
modprobe ip_vs
modprobe ip_vs_rr
modprobe ip_vs_wrr
modprobe ip_vs_sh
modprobe nf_conntrack_ipv4

 chmod +x /etc/rc.local
 添加完毕逐条启动下

11. 配置转发相关参数，否则可能会出错

cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
vm.swappiness=0
EOF

12. 启动并查看

sysctl --system

lsmod | grep ip_vs
如果没有查到就重启下服务器

13. 配置kubelet 使用pause 镜像

查看cgroup
docker info |grep 'Cgroup' | awk 'NR==1{print $3}'
cgroupfs

14. 配置kubelet的cgroups

cat >/etc/sysconfig/kubelet<<EOF
KUBELET_EXTRA_ARGS="--cgroup-driver=cgroupfs --pod-infra-container-image=k8s.gcr.io/pause:3.1"
EOF
这里的 cgroupfs 就是上面查找到的

15. 启动节点

systemctl daemon-reload && systemctl enable kubelet && systemctl restart kubelet

16. 生成master节点的token（这个token 会在24小时候失效，如果在添加需要重新生成）

kubeadm token create --print-join-command 

kubeadm join 192.168.230.141:6443 --token fnpa0m.z5cliojcz5u6xmj9 \
    --discovery-token-ca-cert-hash sha256:86f42f7deedcf786c1d1745b487d62b681b4c0b91bffbfde556430bf4bfc36a2

17. 在新的节点运行新的token

kubeadm join 192.168.230.141:6443 --token fnpa0m.z5cliojcz5u6xmj9 \
    --discovery-token-ca-cert-hash sha256:86f42f7deedcf786c1d1745b487d62b681b4c0b91bffbfde556430bf4bfc36a2

18. 启动成功如图
    

19. 在master 查看新加入的节点