#!/usr/bin/env python
# -*- coding: utf-8 -*-

# An example script for collectd's exec plugin, reading drive temperatures from UDisks2
#
# Notes about the script:
#
# - there are other properties like SmartNumAttributesFailing or SmartNumBadSectors etc
#   (see http://udisks.freedesktop.org/docs/latest/gdbus-org.freedesktop.UDisks2.Drive.Ata.html)
#   which can easily be monitored too, but I've been only interested in temperatures
#
# - drives that have SMART disabled are simply skipped, as calling SmartSetEnabled() would
#   probably require admin privileges, authentication, or changing polkit rules
#   (see http://udisks.freedesktop.org/docs/latest/udisks-polkit-actions.html)
#
# - same with SmartUpdate(), so we're limited to default UDisks2 update interval, whatever it is
#   (seems pretty responsive on my system though)

import dbus
import re
import time
import os
import sys

host = os.environ.get('COLLECTD_HOSTNAME', 'localhost')
interval = float(os.environ.get('COLLECTD_INTERVAL', '60'))
bus = dbus.SystemBus()
manager = dbus.Interface(
    bus.get_object('org.freedesktop.UDisks2', '/org/freedesktop/UDisks2'),
    'org.freedesktop.DBus.ObjectManager')
re_drive = re.compile('(?P<path>.*?/drives/(?P<id>.*))')
while 1:
    objects = manager.GetManagedObjects()
    drives = [m.groupdict() for m in
                 [re_drive.match(path) for path in objects.keys()]
             if m]
    for drive in drives:
        try:
            ata = objects[drive['path']]['org.freedesktop.UDisks2.Drive.Ata']
            if ata['SmartSupported'] and ata['SmartEnabled'] \
            and ata['SmartTemperature'] and ata['SmartUpdated']:
                print 'PUTVAL %s/exec-udisks/temperature-%s interval=%s N:%s' \
                    % (host, drive['id'], interval,
                       ata['SmartTemperature'] - 273.15)
        except KeyError:
            pass
    sys.stdout.flush()
    time.sleep(interval)