0. limit

the number of available CPUs 1 is less than the required 2

1. install Docker

yum update -y

yum remove -y docker docker-common docker-selinux docker-engine
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
yum install -y docker-ce-18.09.0

sed -i -e "/ExecStart/ s/$/ --exec-opt native.cgroupdriver=systemd/" /usr/lib/systemd/system/docker.service
systemctl enable docker && systemctl restart docker && systemctl status docker
docker --version

2. install kubeadm

cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes Repository
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/  
enabled=1
gpgcheck=0
EOF

yum install -y kubeadm kubelet-1.14.0 kubectl-1.14.0 --disableexcludes=kubernetes

systemctl enable kubelet && systemctl start kubelet

3. config

cat > init-config.yaml << EOF
apiVersion: kubeadm.k8s.io/v1beta1
kind: ClusterConfiguration
imageRepository: docker.io/dustise
kubernetesVersion: v1.14.0
networking:
  podSubnet: "10.0.0.0/16"
EOF

cat > /etc/docker/daemon.json << EOF
{
  "registry-mirrors": "https://registry.docker-cn.com"
}
EOF

kubeadm config images pull --config=init-config.yaml

kubeadm init --config=init-config.yaml

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

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 172.21.102.130:6443 --token 5avkfv.8bu2kbbgc85kank0 \
   --discovery-token-ca-cert-hash sha256:904a39a037ac89156ff81b877a70f0f045ee61423b1cb2d82b65039630c6b0c3