Create a KVM VM using Terraform

KVM

Install

• Check if the kvm module is loaded
  kvm-md or kvm-intel also have to be loaded — depending on your chipset

  lsmod | grep -i kvm

• Install virt-manager — that's a package to create VMs with a GUI, but we're only using it to install all of its dependencies

  sudo apt install virt-manager

• Launch libvirt

  sudo systemctl start libvirtd

Setup

To allow terraform to do its thing:

• Edit libvirt configurations

  sudo vi /etc/libvirt/qemu.conf

• Update #security_driver = "selinux" to security_driver = "none"

• Restart libvirt

  sudo systemctl restart libvirtd

Download the image

• For easier debugging: manually get the image and update the root password

  mkdir local
  cd local
  
  wget http://cloud-images.ubuntu.com/jammy/current/jammy-server-cloudimg-amd64.img

  sudo apt install -y libguestfs-tools genisoimage
  sudo virt-customize -a jammy-server-cloudimg-amd64.img --root-password password:mysecretpassword
  
  [   0.0] Examining the guest ...
  [  12.4] Setting a random seed
  virt-customize: warning: random seed could not be set for this type of
  guest
  [  12.4] Setting the machine ID in /etc/machine-id
  [  12.4] Setting passwords
  [  13.5] Finishing off

Create a default storage pool

# Create the directory
$ sudo mkdir -p /kvm/pools/homelab

# Define the "default" pool
$ sudo virsh pool-define-as --name default --type dir --target /kvm/pools/homelab
Pool default defined

# Start the pool
$ sudo virsh pool-start default
Pool default started

# Set the pool to start at the same time as libvirtd
$ sudo virsh pool-autostart default
Pool default marked as autostarted

---

Launch

• Install terraform plugins

  $ terraform init
  

• Create SSH Keys

  mkdir .ssh
  ssh-keygen -t ed25519 -b 4096 -f .ssh/id_ed25519
  

• Check the plan

  $ terraform plan
  

• Launch it

  $ sudo terraform apply
  

Check

$ sudo virsh list --all
 Id   Name   State
----------------------
 1    test   running

$ sudo virsh net-dhcp-leases default
 Expiry Time           MAC address   Protocol   IP address          Hostname   Client ID or DUID
-----------------------------------------------------------------------------------------------------------------------------------------------
 2024-03-16 11:28:18   ...           ipv4       192.168.122.21/24   ubuntu     ...

$ terraform output
vm_ips = [
  tolist([
    "192.168.122.21",
  ]),
]

$ ssh -i .ssh/id_ed25519 ubuntu@192.168.122.21
Welcome to Ubuntu 22.04.4 LTS (GNU/Linux 5.15.0-100-generic x86_64)

ubuntu@test:~$ 

Clean up

$ sudo terraform destroy -auto-approve