CentOS k8s cluster with vagrant-libvirt

Vagrantfile

# -*- mode: ruby -*-
# vi: set ft=ruby :

$master_cpus = 2
$master_memory = 2048
$num_workers = 3
$worker_cpus = 4
$worker_memory = 4096

$common_script = <<-SCRIPT
# Prerequisite
sed -i --follow-symlinks 's/SELINUX=enforcing/SELINUX=disabled/' /etc/sysconfig/selinux
swapoff -a
sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
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
yum update

# 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 makecache fast
yum remove docker docker-common docker-selinux docker-engine
yum install -y docker-ce
systemctl restart docker && systemctl enable docker

# Install kubeadm and kubelet
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 makecache fast
yum install -y kubeadm kubectl
sed -i 's/cgroup-driver=systemd/cgroup-driver=cgroupfs/' /etc/systemd/system/kubelet.service.d/10-kubeadm.conf
systemctl daemon-reload
systemctl enable kubelet
SCRIPT

$master_script = <<-SCRIPT
kubeadm init --apiserver-advertise-address=192.168.33.100 --pod-network-cidr=10.244.0.0/16

seq 1 5 | xargs -I% echo 192.168.33.10% k8s-node% >> /etc/hosts

sudo -u vagrant mkdir -p /home/vagrant/.kube
cp -i /etc/kubernetes/admin.conf /home/vagrant/.kube/config
chown $(id -u vagrant):$(id -g vagrant) /home/vagrant/.kube/config

sudo -u vagrant kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.10.0/Documentation/kube-flannel.yml

systemctl enable kubelet
systemctl start kubelet

echo "alias k='kubectl'" >> /home/vagrant/.bashrc
echo "source <(kubectl completion bash)" >> /home/vagrant/.bashrc
SCRIPT

Vagrant.configure('2') do |config|
  config.vm.box = 'centos/7'
  config.vm.box_check_update = false
  config.ssh.insert_key = false

  config.vm.define 'master' do |master|
    master.vm.hostname = 'k8s-master'
    master.vm.network 'private_network', ip: '192.168.33.100'
    master.vm.provision 'shell', inline: $common_script
    master.vm.provision 'shell', inline: $master_script

    master.vm.provider :libvirt do |libvert|
      libvert.cpus = $master_cpus
      libvert.memory = $master_memory
    end
  end

  (1..$num_workers).each do |i|
    config.vm.define "node#{i}" do |node|
      node.vm.hostname = "k8s-node#{i}"
      node.vm.network 'private_network', ip: "192.168.33.#{i + 100}"
      node.vm.provision 'shell', inline: $common_script

      node.vm.provider :libvirt do |libvert|
        libvert.cpus = $worker_cpus
        libvert.memory = $worker_memory
      end
    end
  end
end