Cluster Kubernetes using virtualbox with Debian Stretch

instructions.sh

##On the first VM
apt-get install -y apt-transport-https ca-certificates curl software-properties-common gnupg2
curl -fsSL https://download.docker.com/linux/debian/gpg | sudo apt-key add -
add-apt-repository    "deb [arch=amd64] https://download.docker.com/linux/debian $(lsb_release -cs) stable"
apt-get update
apt-cache madison docker-ce
apt-get install docker-ce=18.06.0~ce~3-0~debian
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
cat <<EOF >/etc/apt/sources.list.d/kubernetes.list
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt-get update
apt-get install -y kubelet kubeadm kubectl
apt-mark hold kubelet kubeadm kubectl
swapoff -a
vi /etc/fstab 
cat /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
sed -i "s/\$KUBELET_EXTRA_ARGS/\$KUBELET_EXTRA_ARGS\ --cgroup-driver=systemd/g" /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
cat <<EOF >/etc/docker/daemon.json
{ 
   "exec-opts": ["native.cgroupdriver=systemd"]
}
EOF
systemctl daemon-reload
systemctl restart kubelet
systemctl restart docker
## CLONE VM
#ip and uuid have to be different
cat /sys/class/dmi/id/product_uuid
ip a
kubeadm init --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.1.20
cp /etc/kubernetes/admin.conf $HOME/
chown $(id -u):$(id -g) $HOME/admin.conf
export KUBECONFIG=$HOME/admin.conf
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.11.0/Documentation/kube-flannel.yml

##DONE
kubectl get nodes --all-namespaces