start_node.yml

---
- name: Start node
  hosts: localhost
  connection: local
  gather_facts: false

  tasks:

  # Calculate the IP address from the `instance` input variable, and then do a
  # reverse DNS lookup to find the FQDN, which in this environment is equal to
  # the name of the virtual machine.
  - set_fact:
      vm_ip: "{{ instance | regex_replace(':.*$') }}"
  - set_fact:
      vm_name: "{{ lookup('dig', vm_ip + '/PTR') | regex_replace('\\.$') }}"

  # Retrieve the facts of the virtual machine, so that we can check that it
  # exists:
  - ovirt_vms_facts:
      pattern: "name={{ vm_name }}"
  - debug:
      var: ovirt_vms

  # Fail if the virtual machine doesn't exist:
  - fail:
      msg: "Virtual machine '{{ vm_name }}' doesn't exist"
    when: ovirt_vms | length == 0

  # Make sure tha the virtual machine is running:
  - ovirt_vms:
      name: "{{ vm_name }}"
      state: running