/**
* Helper function to resolve reference to another machine.
*
* @param $reference_name Name of the reference in AbstractMachine::references.
* @param $properties_cache Properties of referencing machine.
* @return Reference to referred machine.
*/
protected function resolveMachineReference($reference_name, $properties_cache)
{
if (!isset($this->references[$reference_name])) {
throw new \InvalidArgumentException('Unknown reference: ' . $reference_name);
}
// Get reference configuration
$r = $this->references[$reference_name];
// Get referenced machine id
$ref_machine_id = array();
foreach ($r['machine_id'] as $mid_prop) {
$ref_machine_id[] = $properties_cache[$mid_prop];
}
// Get referenced machine type
$ref_machine_type = $r['machine_type'];
return new Reference($this->backend->getMachine($ref_machine_type), $ref_machine_id);
}
