increase_node_cpus.yml

---
- name: Increase node CPUs
  hosts: localhost
  connection: local
  gather_facts: false

  # These variables are intended to be overriden using the `--extra-vars`
  # command line option:
  vars:
    # Maximum number of CPUs to assing to the VM.
    max_cpus: 4
    # Amount of CPUs to add in each increase.
    inc_cpus: 1

  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 and get its current amount of CPUs:
  - 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

  # Extract the current number of CPUs. Note that we get and increase the number
  # os sockets, not the number of cores per socket, because that is what can be
  # changed without restarting the virtual machine in oVirt.
  - set_fact:
      current_cpus: "{{ ovirt_vms[0].cpu.topology.sockets }}"
      var: current_cpus

  # Calculate the new number of CPUs:
  - set_fact:
      new_cpus: "{{ [current_cpus|int + inc_cpus|int, max_cpus|int] | min }}"
  - debug:
      var: new_cpus

  # Update the virtual machine with the new number of CPUs:
  - ovirt_vms:
      name: "{{ vm_name }}"
      cpu_sockets: "{{ new_cpus }}"
    when: new_cpus > current_cpus