Hal Dbus and Python

Stephen
IT, linux, systemadmin
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How to tie into dbus to get alerts on had drive device insertion also generates pretty notifications.

Its the first set in making the code decrypt a usb device on insertion run a rdiff backup and then eject the device.

Step two is to work out how to generate a key file for a pass phrase with luks.

import pynotify
import dbus
import gobject
from dbus.mainloop.glib import DBusGMainLoop
import time
class DeviceFinder ( ):

     def run ( self ):
          pynotify.init( "AutoRdiff" )
          n = pynotify.Notification("Auto Rdiff", "Application Started")
          n.set_urgency(pynotify.URGENCY_LOW)
          n.set_timeout(2)
          n.show()
          DBusGMainLoop(set_as_default=True)
          self.dbus()

     def dbus ( self ):
          self.bus = dbus.SystemBus()
          self.hal_manager_obj = self.bus.get_object(
                                             "org.freedesktop.Hal",
                                              "/org/freedesktop/Hal/Manager")
          self.hal_manager = dbus.Interface(self.hal_manager_obj,
                                               "org.freedesktop.Hal.Manager")
          self.hal_manager.connect_to_signal("DeviceAdded", self._filter)

     def _filter(self, udi):
          device_obj = self.bus.get_object ("org.freedesktop.Hal", udi)
          device = dbus.Interface(device_obj, "org.freedesktop.Hal.Device")

          if device.QueryCapability("volume"):
               return self.do_something(device)

     def do_something(self, volume):
          #give the device time to get mounted
          time.sleep(4)
          device_file = volume.GetProperty("block.device")
          label = volume.GetProperty("volume.label")
          fstype = volume.GetProperty("volume.fstype")
          mounted = volume.GetProperty("volume.is_mounted")
          mount_point = volume.GetProperty("volume.mount_point")
          try:
              size = volume.GetProperty("volume.size")
          except:
              size = 0

          print "New storage device detectec:"
          print "  device_file: %s" % device_file
          print "  label: %s" % label
          print "  fstype: %s" % fstype

          if mounted:
              print "  mount_point: %s" % mount_point
          else:
              print "  not mounted"
          print "  size: %s (%.2fGB)" % (size, float(size) / 1024**3)

          n = pynotify.Notification("Auto Rdiff", " mount_point: %s" % mount_point)
          n.set_urgency(pynotify.URGENCY_LOW)
          n.set_timeout(2)
          n.show()