sample-servers.php

<?php
class MachineDescription {
  public $name, $type;
  
  public function __construct($name, $type) {
    $this->name = $name;
    $this->type = $type;
  }
}

$query_result = mysqli_query(); // whatever you need to query
$machines = [];

foreach($row in mysqli_fetch_assoc($query_result)) {
  $machines[] = new MachineDescription($row['name'], $row['type']);
}

return json_encode($machines);