I am thinking ruby-dbus could be the right solution, but I cannot seem to find any examples of how to detect in realtime, whenever a storage device is connected to the Linux machine. Anyone have such an example?
There seems to be numerous different approaches you could take.
Here's a Ruby implementation I found that links into libusb with Ruby FFI.
What's good about this is that libusb supports hotplug notifications, so this could be something that does what you need:
http://libusb.sourceforge.net/api-1.0/hotplug.html
From the libusb Ruby docs:
Device hotplug support
Support for device hotplugging can be used, if
LIBUSB.has_capability?(:CAP_HAS_HOTPLUG)returns true. This requires libusb-1.0.16 or newer on Linux or MacOS. Windows support is still on the way.A hotplug event handler can be registered with {
LIBUSB::Context#on_hotplug_event}. You then need to call {LIBUSB::Context#handle_events} in order to receive any events. This can be done as blocking calls (possibly in it's own thread) or by using {LIBUSB::Context#pollfds} to detect any events to handle.