Vagrant based K8s cluster on CentOS/7

Vagrantfile

# Author: vaclav.sykora@oracle.com
# Description: Installs Docker Engine and setup Kubernetes cluster
#
# Optional plugins:
#     vagrant-proxyconf (if you don't have direct access to the Internet)
#         see https://github.com/tmatilai/vagrant-proxyconf for configuration
#
# Usage:
# > vagrant plugin install vagrant-proxyconf  # optional, in case you are behind a corporate proxy server
# > vagrant init  # optional, just to initialize the current directory to be a Vagrant environment
# > vagrant up
# > vagrant ssh-config >> ~/.ssh/config
# > sudo vi /etc/hosts
#   * add '127.0.0.1 master node1 node2'


nodes = [
  { :hostname => 'master',  :ip => '10.0.0.10', :id => '10' }, # use two digits id(s)
  { :hostname => 'node1',   :ip => '10.0.0.11', :id => '11' },
  { :hostname => 'node2',   :ip => '10.0.0.12', :id => '12' },
]

memory = 2000
domain   = 'kube'
hosts = nodes.map { |h| "#{h[:ip]} #{h[:hostname]} #{h[:hostname]}.#{domain}" }.join('\n')

$script = <<-SCRIPT
  echo -e "127.0.0.1 localhost localhost.localdomain\\n#{hosts}" > /etc/hosts
  echo "--->>> Disable SELinux"
  setenforce 0
  sed -i --follow-symlinks 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/sysconfig/selinux
  echo "--->>> Disable Swap"
  swapoff -a
  sed -i '/^.* swap /s/^#*/#/g' /etc/fstab
  echo "--->>> Enable br_netfilter"
  modprobe br_netfilter
  echo -e "net.bridge.bridge-nf-call-iptables = 1\nnet.ipv4.ip_forward = 1" >> /etc/sysctl.conf
  sysctl -p
  echo "--->>> Install Docker"
  yum install -y yum-utils device-mapper-persistent-data lvm2
  yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
  yum install -y docker-ce
  systemctl start docker && systemctl enable docker
  gpasswd -a vagrant docker
  echo "--->>> Install Kubernetes"
  cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
        https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
  yum install -y kubelet kubeadm kubectl
  echo "--->>> Bootstrap a secure Kubernetes cluster"
  if [ "$HOSTNAME" = master ]; then
    echo "--->>> Initializing the master"
    kubeadm reset --force
    kubeadm init --apiserver-advertise-address=10.0.0.10 --pod-network-cidr=10.244.0.0/16 | tee /var/tmp/kubeadm_init.stdout
    echo "--->>> Installing a pod network add-on"
    export KUBECONFIG=/etc/kubernetes/admin.conf
    kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"
  else
    echo "--->>> Joining the node(s)"
    cmd=$(ssh -o StrictHostKeyChecking=no -i /home/vagrant/.ssh/id_rsa vagrant@master "cat /var/tmp/kubeadm_init.stdout | grep 'kubeadm join ' | sed -e 's/^[ \t]*//'")
    [ -z "$cmd" ] && echo "---!!! Failed to get command (join new node)" && exit 1
    echo "Starting: $cmd"
    eval $cmd
  fi
  chmod o+r /etc/kubernetes/admin.conf
  grep KUBECONFIG /home/vagrant/.bashrc; if [[ $? != 0 ]]; then echo 'export KUBECONFIG=/etc/kubernetes/admin.conf' >> /home/vagrant/.bashrc; fi
  grep KUBECONFIG /root/.bashrc; if [[ $? != 0 ]]; then echo 'export KUBECONFIG=/etc/kubernetes/admin.conf' >> /root/.bashrc; fi
  systemctl start kubelet && systemctl enable kubelet
SCRIPT


Vagrant.configure('2') do |config|
  config.ssh.insert_key = false
  if Vagrant.has_plugin?('vagrant-proxyconf')
    ['http_proxy', 'HTTP_PROXY', 'https_proxy', 'HTTPS_PROXY', 'no_proxy', 'NO_PROXY'].each do |var|
      if proxy = ENV[var]
        case var.downcase
        when 'http_proxy'
          config.proxy.http = proxy
        when 'https_proxy'
          config.proxy.https = proxy
        when 'no_proxy'
          cluster_no_proxy = [".#{domain}"]
          cluster_no_proxy.push(nodes.map { |h| h[:hostname] }).push(nodes.map { |h| h[:ip] })
          proxy += ",#{cluster_no_proxy.flatten.join(',')}"
          config.proxy.no_proxy = proxy
        end
        puts "#{var}: #{proxy}"
      end
    end
  end
  nodes.each do |node|
    config.vm.define node[:hostname] do |nodeconfig|
      nodeconfig.vm.box = 'centos/7'
      nodeconfig.vm.hostname = node[:hostname]
      nodeconfig.vm.network :private_network, ip: node[:ip], virtualbox__intnet: domain
      nodeconfig.vm.provider :virtualbox do |vb|
        vb.name = "#{node[:hostname]}.#{domain}"
        vb.memory = memory
        vb.cpus = 1
        vb.customize ['modifyvm', :id, '--natdnshostresolver1', 'on']
        vb.customize ['modifyvm', :id, '--natdnsproxy1', 'on']
        vb.customize ['modifyvm', :id, '--macaddress1', "5CA1AB1E00#{node[:id]}"]
        vb.customize ['modifyvm', :id, '--natnet1', '192.168/16']
      end
      nodeconfig.vm.provision 'file', source: '~/.vagrant.d/insecure_private_key', destination: '/home/vagrant/.ssh/id_rsa'
      nodeconfig.vm.provision 'shell', inline: $script, run: 'once'
    end
  end
end