Ansible role to provision KVM virtual machines with multi-network support, automatic disk resize, cloud-init guest customization, and DNS via NetworkManager dnsmasq.

Host packages:

qemu-img virt-install genisoimage libvirt

Ansible collections:

ansible-galaxy collection install -r requirements.yml

Your user must have permission to manage libvirt (e.g. member of the libvirt group, polkit rules, or socket activation).

Base images must be placed manually in the image cache directory (default /var/lib/libvirt/images/.cache/).

cp group_vars/all/vars.yml.example group_vars/all/vars.yml
# edit vars.yml with your values
ansible-galaxy collection install -r requirements.yml
ansible-playbook provision.yml

Both base_image and os_variant can be overridden per-VM (see example below).

vms:
  - name: bastion
    vcpus: 2
    memory: 4096        # MiB
    disk_size: 200       # GiB -- the cloud image disk is resized to this
    extra_disks:         # optional additional disks
      - name: data       # creates <fqdn>-data.qcow2
        size: 50         # GiB
    networks:
      - type: bridge     # host bridge -- DHCP from your router
        source: br0
      - type: network    # libvirt NAT network
        source: default
      - type: network    # libvirt isolated/airgap network
        source: airgap
        ip: 192.168.127.5
        prefix: 24

  - name: master-0
    base_image: rhcos-disc.qcow2          # per-VM override
    os_variant: fedora-coreos-stable       # per-VM override
    vcpus: 4
    memory: 16384
    disk_size: 120
    networks:
      - type: bridge
        source: br0
      - type: network
        source: default
      - type: network
        source: airgap
        ip: 192.168.127.10
        prefix: 24

Each VM gets the FQDN <name>[.<cluster_name>].<dns_domain>:

• cluster_name: "" -> bastion.rhuk.local
• cluster_name: ocp -> bastion.ocp.rhuk.local

NICs with a static ip get a cloud-init static config; NICs without ip use DHCP. Guest NICs are renamed to net0, net1, net2, etc. via cloud-init set-name for consistent naming regardless of the underlying driver.

The role configures NetworkManager to use its built-in dnsmasq instance, then drops config files into /etc/NetworkManager/dnsmasq.d/:

• Host entries -- each VM with a static IP gets an address=/fqdn/ip record so you can ssh bastion.ocp.rhuk.local from the hypervisor.
• Wildcard -- when apps_wildcard_ip is set, *.apps.[cluster.]domain resolves to that IP (useful for OpenShift / ingress).

The bridge is assumed to already exist on the host. The NAT and airgap networks are created by the role if they don't exist.

Destroy VMs, disks, ISOs, and DNS config:

ansible-playbook teardown.yml

Destroy libvirt networks (NAT and airgap):

ansible-playbook teardown-networks.yml