make-multipass-inventory.yaml

# This play is intended to be run on the control node (localhost), for every host
#
# A Multipass VM is launched for each host in the inventory.  It is expected that
# SSH Host Key Checking is disabled (e.g. in ansible.cfg) so that Ansible can
# connect to the newly launced VMs without human intervention.
#
# The way that the play learns the VM IP address is suboptimal because it needs
# to be repeated in each separate playbook (i.e. playbooks run by themselves).
# So expect in future to see usage of kidkafka9's inventory plugin instead.

- name: The inventory is realised as Multipass VMs under our control
  hosts: all
  gather_facts: false
  tasks:

  - name: Localhost has an OpenSSH Keypair with which to control hosts
    run_once: True
    delegate_to: localhost
    community.crypto.openssh_keypair:
      path: id_ansible_rsa
      size: 2048
    register: generated_ansible_ssh_key

  # This will fail if the VM doesn't exist.  Failure is fine and is ignored.
  - name: Test to see if the Host is already a Multipass VM
    delegate_to: localhost
    ignore_errors: true
    ansible.builtin.command:
      cmd: "multipass info --format json {{ inventory_hostname|quote }}"
    register: vm_status

  - name: Learn whether or not the Host is a Multipass VM
    ansible.builtin.set_fact:
      is_a_multipass_vm: "{{ vm_status.rc == 0 }}"
      cacheable: yes

  - name: Learn the state of the Multipass VM
    when: is_a_multipass_vm
    ansible.builtin.set_fact:
      vm_state: "{{ vm_status.stdout | from_json | community.general.json_query('info.\"' ~ inventory_hostname ~ '\".state') }}"
      cacheable: yes

  - name: Start a stopped Multipass VM
    delegate_to: localhost
    when: is_a_multipass_vm and vm_state == "Stopped"
    ansible.builtin.command:
      cmd: "multipass start {{ inventory_hostname|quote }}"

  # Perform this task one host at a time to avoid some kind of rate-limiting that
  # shows-up as a multipass error: launch failed: Remote "" is unknown or unreachable
  - name: Create the Host as a Multipass VM
    delegate_to: localhost
    throttle: 1
    when: not is_a_multipass_vm
    ansible.builtin.command:
      cmd: "multipass launch -v --timeout 360 --cloud-init - --name {{ inventory_hostname|quote }} -d 7G jammy"
      stdin: "{{ lookup('ansible.builtin.template', 'cloud-init.yaml.j2') }}"
    vars:
      ssh_pubkey: "{{ generated_ansible_ssh_key.public_key }}"
      ip_address_and_mask: "{{ ansible_host }}/24"
    register: vm_created

  - name: Update the Inventory with facts about the Multipass VMs
    ansible.builtin.include_tasks: tasks/update-multipass-inventory.yaml

  - name: Allow the VMs to resolve each other's names
    ansible.builtin.include_tasks: tasks/network-multipass-inventory.yaml