Deployment With Kubeadm Provision VMs With Vagrant

In this lesson we provision a small kube-node2 cluster: one Kubernetes master and two worker nodes. We use VirtualBox as the hypervisor and Vagrant to automate VM creation and provisioning so everyone can reproduce the same environment with a single command. Tools used

VirtualBox — hypervisor for running the VMs.
Vagrant — automation tool to define, create, and provision multiple VMs from a single Vagrantfile.

Prerequisites

Install VirtualBox for your OS: https://www.virtualbox.org
Install Vagrant: https://www.vagrantup.com/docs
Download or clone the lesson repository so the Vagrantfile and provisioning scripts (the ubuntu/ directory) are available locally.

A screenshot of the VirtualBox "Download VirtualBox" webpage showing version 7.0.6 platform packages and download links in a browser window. The browser UI and Windows taskbar are visible at the top and bottom of the screen.

If you obtained the lesson files from a repository, clone it:

git clone <repository-url>

Then change into the repository and confirm the Vagrantfile and supporting folders exist:

cd certified-kubernetes-administrator-course
ls -la
# Expected output includes: Vagrantfile  ubuntu/  resources/  README.md  etc.

The repository and Vagrantfile are included with the lesson materials:

A screenshot of a GitHub repository page for the "Certified Kubernetes Administrator (CKA) Course" showing the file list (docs, images, resources, etc.) and the README content. The right sidebar displays repository stats like stars, forks, and contributors.

Open the Vagrantfile to review the VM configuration. The file below defines the base box and the provisioning for the master node; worker nodes are configured further down in the same file:

# -*- mode: ruby -*-
# Define the number of master and worker nodes
# If this number is changed, remember to update setup-hosts.sh script with the new hosts IP details in /etc/hosts of each VM.
NUM_MASTER_NODE = 1
NUM_WORKER_NODE = 2

IP_NW = "192.168.56."
MASTER_IP_START = 1
NODE_IP_START = 2

Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/bionic64"
  config.vm.box_check_update = false

  # Provision Master Nodes
  (1..NUM_MASTER_NODE).each do |i|
    config.vm.define "kubemaster" do |node|
      node.vm.provider "virtualbox" do |vb|
        vb.name = "kubemaster"
        vb.memory = 2048
        vb.cpus = 2
      end
      node.vm.hostname = "kubemaster"
      node.vm.network :private_network, ip: IP_NW + "#{MASTER_IP_START + i}"
      node.vm.network "forwarded_port", guest: 22, host: "#{2710 + i}"

      node.vm.provision "setup-hosts", :type => "shell", :path => "ubuntu/vagrant/setup-hosts.sh" do |s|
        s.args = ["enp0s8"]
      end

      node.vm.provision "setup-dns", type: "shell", :path => "ubuntu/update-dns.sh"
    end
  end

  # Worker nodes and other configuration follow...
end

What to notice in this configuration

The VMs use a host-only network in the 192.168.56.x range.
Hostnames, /etc/hosts entries, DNS, and additional configuration are applied by provisioning scripts under ubuntu/.
SSH port forwarding uses the pattern host_port = 2710 + i for each defined VM.

Cluster VM details (summary)

VM name	Role	Private IP pattern	SSH host port formula
`kubemaster`	Kubernetes master	`192.168.56.<MASTER_IP_START + i>`	`2710 + i` (e.g., `2711` for i=1)
`kubenode01`, `kubenode02`	Worker nodes	`192.168.56.<NODE_IP_START + i>`	`2710 + i` (incrementing per VM)

Bringing up the VMs First check the current Vagrant machine state:

vagrant status

Before creating the machines you will see them as “not created”:

Current machine states:

kubemaster               not created (virtualbox)
kubenode01               not created (virtualbox)
kubenode02               not created (virtualbox)

Start all VMs and run provisioning with:

vagrant up

Vagrant will download the ubuntu/bionic64 box if needed, create the VMs, set networking and resources, and run the provisioning scripts. This can take several minutes. Example provisioning output (abbreviated):

Bringing machine 'kubemaster' up with 'virtualbox' provider...
==> kubemaster: Importing base box 'ubuntu/bionic64'...
==> kubemaster: Setting the name of the VM: kubemaster
==> kubemaster: Preparing network interfaces based on configuration...
==> kubemaster: Forwarding ports...
kubemaster: 22 (guest) => 2711 (host)
==> kubemaster: Booting VM...
==> kubemaster: Waiting for machine to boot. This may take a few minutes...
kubemaster: SSH address: 127.0.0.1:2222
kubemaster: SSH username: vagrant
kubemaster: SSH auth method: private key
==> kubemaster: Machine booted and ready!
==> kubemaster: Running provisioner: setup-hosts (shell)...
==> kubemaster: Running provisioner: setup-dns (shell)...
# Similar output for kubenode01 and kubenode02

If you see VirtualBox Guest Additions mismatch warnings or shared folder issues during provisioning, they are common. To resolve these, either update the guest additions inside the VMs to match your host VirtualBox version or use the vagrant-vbguest plugin to automate guest additions management: https://github.com/dotless-de/vagrant-vbguest

After vagrant up finishes, verify the VMs are running:

vagrant status

Expected output:

Current machine states:

kubemaster               running (virtualbox)
kubenode01               running (virtualbox)
kubenode02               running (virtualbox)

Connecting to the VMs Use vagrant ssh with the VM name to open a shell on any VM:

vagrant ssh kubemaster
vagrant ssh kubenode01
vagrant ssh kubenode02

Inside a VM you can run standard commands to verify networking and system status:

# Example session
vagrant ssh kubenode02
# vagrant@kubenode02:~$ uptime
# vagrant@kubenode02:~$ ip addr show enp0s8
# vagrant@kubenode02:~$ logout

When you’re done with a VM shell, use exit or logout to return to your host. Next steps You now have three provisioned VMs (one master, two workers) reachable via vagrant ssh. Use these machines to follow the kubeadm-based Kubernetes installation and cluster configuration steps in the next lessons. Useful references

VirtualBox: https://www.virtualbox.org
Vagrant documentation: https://www.vagrantup.com/docs
vagrant-vbguest plugin: https://github.com/dotless-de/vagrant-vbguest

Introduction

Core Concepts

Scheduling

Logging & Monitoring

Application Lifecycle Management

Cluster Maintenance

Security

Storage

Networking

Design and Install a Kubernetes Cluster

Install "Kubernetes the kubeadm way"

Troubleshooting

Helm Basics (2025 Updates)

Kustomize Basics (2025 Updates)

Other Topics

Mock Exams

Deployment With Kubeadm Provision VMs With Vagrant

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