use vagrant and k3s to deploy a kubernetes cluster in local VM

Vagrantfile

# run a kubernetes cluster in local VM using vagrant + k3s
# require: Virtualbox, vagrant
# steps: 
# * in the folder contain this `Vagrantfile`, run `vagrant up` and wait a bit for provisioning.
#   Once done, `vagrant ssh master` into the node and start using the k8s cluster,
#   such as `kubectl get nodes`, `kubectl get pods -A`, `kubectl get componentstatus`, 
#   or `kubectl run busybox --image=busybox:1.28 --rm --restart=Never -it -- nslookup kubernetes`
# * To clean up, logout these nodes, then run `vagrant destroy` to destroy the VMs.
#   - next time run `vagrant up` again to provision again
#   - or run `vagrant halt` to halt these VMs, and bring them back to the same state 
#     by `vagrant up` next time.
#
# modified from https://github.com/michaelc0n/k3s/blob/master/Vagrantfile
default_box = 'ubuntu/bionic64'

Vagrant.configure(2) do |config|
  config.vm.define 'master' do |master|
    master.vm.box = default_box
    master.vm.hostname = "master"
    master.vm.synced_folder ".", "/vagrant", type:"virtualbox"
    master.vm.network 'private_network', ip: "192.168.0.200",  virtualbox__intnet: true
    for p in 30000..30100
      master.vm.network "forwarded_port", guest: p, host: p, protocol: "tcp"
    end
    master.vm.provider "virtualbox" do |v|
      v.memory = "1024"
      v.name = "k3s-master01"
    end

    master.vm.provision "shell", inline: <<-SHELL
      sudo apt update
      sudo apt install etcd-server etcd-client -y
      IPADDR=$(ip a show enp0s8 | grep "inet " | awk '{print $2}' | cut -d / -f1)
      curl -sfL https://get.k3s.io | INSTALL_K3S_EXEC="--node-ip=${IPADDR} --flannel-iface=enp0s8 --write-kubeconfig-mode 644 --kube-apiserver-arg="service-node-port-range=30000-30100" --no-deploy=servicelb --no-deploy=traefik" K3S_STORAGE_BACKEND=etcd3 K3S_STORAGE_ENDPOINT="http://127.0.0.1:2379" sh -
      NODE_TOKEN="/var/lib/rancher/k3s/server/node-token"
      while [ ! -e ${NODE_TOKEN} ]
      do
          sleep 2
      done
      cat ${NODE_TOKEN}
      cp ${NODE_TOKEN} /vagrant/
      KUBE_CONFIG="/etc/rancher/k3s/k3s.yaml"
      cp ${KUBE_CONFIG} /vagrant/ #copy contents of "k3s.yaml" to ".kube/config" to 'kubectl' from local-machine
    SHELL
  end

  config.vm.define 'node1' do |node1|
    node1.vm.box = default_box
    node1.vm.hostname = "node1"
    node1.vm.synced_folder ".", "/vagrant", type:"virtualbox"
    node1.vm.network 'private_network', ip: "192.168.0.201",  virtualbox__intnet: true
    node1.vm.provider "virtualbox" do |v|
      v.memory = "1024"
      v.name = "k3s-node01"
      end
    
    node1.vm.provision "shell", inline: <<-SHELL
      IPADDR=$(ip a show enp0s8 | grep "inet " | awk '{print $2}' | cut -d / -f1)
      curl -sfL https://get.k3s.io | INSTALL_K3S_EXEC="--node-ip=${IPADDR} --flannel-iface=enp0s8" K3S_URL=https://192.168.0.200:6443 K3S_TOKEN=$(cat /vagrant/node-token) sh -
    SHELL
  end

end