$ sudo# hostnamectl set-hostname $hostname

$# sudo yum update -y && yum install -y yum-utils device-mapper-persistent-data lvm2 
$ sudo# yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
$ sudo# yum install -y docker-ce
$# sudo systemctl start docker && sudo systemctl enable docker

$ sudo# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

$# sudo setenforce 0 
$# sudo sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config

$ sudo# yum update -y && sudo yum install -y net-tools wget setuptool perl python-sphinx gcc make python-devel openssl-devel kernel-devel graphviz kernel-debug-devel autoconf automake rpm-build redhat-rpm-config libtool python-six checkpolicy selinux-policy-devel unbound-devel

$# sudo reboot

$ sudo# systemctl start openvswitch && sudo systemctl enable openvswitch

$ sudo# sed -i '/set ovsdb-server \"$DB_FILE\"/a \        set \"$@\" --remote=ptcp:6650' /usr/share/openvswitch/scripts/ovs-ctl
$ sudo# systemctl restart openvswitch

$# sudo bash -c 'cat <<EOF > /etc/sysctl.d/k8s.conf
net.ipv4.ip_forward = 1
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF'

$# sudo sysctl --system

$ sudo# systemctl stop firewalld
$ sudo# systemctl disable firewalld

$# sudo swapoff -a

$ sudo# bash -c 'cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
exclude=kube*
EOF'

$# sudo yum install -y kubelet kubeadm kubectl --disableexcludes=kubernetes
$ sudo# systemctl enable kubelet && sudo systemctl start kubelet

$# kubectl delete ds kube-proxy -n kube-system

$ sudo# iptables -t nat -F
$ sudo# iptables -F
$ sudo# iptables -X