"options":
  "virtual_ip":
    "type": "string"
    "default": ""
    "description": |
      Virtual IP/netmask that will be moved between instances,
      e.g.: 10.1.2.3/16
  "vip_hostname":
    "type": "string"
    "default": ""
    "description": |
      A VIP hostname to pass to clients.
  "port":
    "type": "int"
    "default": !!int "443"
    "description": |
      A port to pass to clients.
  "router_id":
    "type": "int"
    "default": !!int "23"
    "description": |
      Virtual router identifier - a number between 1 and 255
      that's unique within the network segment
  "network_interface":
    "type": "string"
    "default": ""
    "description": |
      Network interface name for the VIP. The default value is
      the result of running the following command:
      `route | grep default | head -n 1 | awk {'print $8'}`.
  "healthcheck_interval":
    "type": "int"
    "default": !!int "2"
    "description": |
      vrrp_script-based health-check interval, in seconds