#!/usr/bin/python3
# Nagios plugin to check the system state according to systemd.

from __future__ import division, print_function
import posixpath
import subprocess
import sys


try:
    import dbus
except ImportError:
    print("UNKNOWN: Please install python-dbus")
    sys.exit(3)


bus = dbus.SystemBus()
proxy = bus.get_object('org.freedesktop.systemd1', '/org/freedesktop/systemd1')


def get_system_state():
    """Get system state."""
    properties = dbus.Interface(proxy, 'org.freedesktop.DBus.Properties')
    system_state = properties.Get('org.freedesktop.systemd1.Manager', 'SystemState')
    return system_state


def get_failed_units():
    """Get a list of failed system units."""
    manager = dbus.Interface(proxy, 'org.freedesktop.systemd1.Manager')
    units = manager.ListUnits()
    failed_units = []
    for u in units:
        service, _, loaded, active, state = u[:5]
        if active == 'failed':
            failed_units.append(service)
    return failed_units


system_state = get_system_state()
if system_state in ['running', 'starting']:
    print('OK: {}'.format(system_state))
    sys.exit(0)
else:
    print('CRIT: {}, failed: {}'.format(system_state, " ".join(get_failed_units())))
    sys.exit(2)

# vim:tw=120: