CasperSecurity
#!/usr/bin/python3
# Copyright (c) 2009-2018 Canonical Ltd
#
# AUTHOR:
# Michael Vogt <mvo@ubuntu.com>
# Balint Reczey <rbalint@ubuntu.com>
#
# unattended-upgrade-shutdown - helper that checks if a
# unattended-upgrade is in progress and waits until it exists
#
# This file is part of unattended-upgrades
#
# unattended-upgrades is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as published
# by the Free Software Foundation; either version 2 of the License, or (at
# your option) any later version.
#
# unattended-upgrades is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with unattended-upgrades; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
import copy
import dbus
import signal
import sys
import time
import logging
import logging.handlers
import gettext
import subprocess
import os.path
# for dbus signal handling
try:
from dbus.mainloop.glib import DBusGMainLoop
from gi.repository import GLib
except ImportError:
pass
from optparse import OptionParser, Values
Values # pyflakes
from gettext import gettext as _
from threading import Event
try:
import apt_pkg
except Exception:
# if there is no python-apt no unattended-upgrades can run so not
# need to stop the shutdown
logging.exception("importing of apt_pkg failed, exiting")
sys.exit(0)
def do_usplash(msg):
# type: (str) -> None
if os.path.exists("/sbin/usplash_write"):
logging.debug("Running usplash_write")
subprocess.call(["/sbin/usplash_write", "TEXT", msg])
subprocess.call(["/sbin/usplash_write", "PULSATE"])
def do_plymouth(msg):
# type: (str) -> None
if os.path.exists("/bin/plymouth"):
for line in msg.split("\n"):
logging.debug("Running plymouth --text")
subprocess.call(["/bin/plymouth", "message", "--text", line])
def log_msg(msg, level=logging.WARN):
# type: (str, int) -> None
""" helper that will print msg to usplash, plymouth, console """
logging.log(level, msg)
do_plymouth(msg)
do_usplash(msg)
def log_progress():
# type: () -> None
""" helper to log the install progress (if any) """
# wait a some seconds and try again
msg = _("Unattended-upgrade in progress during shutdown, "
"please don't turn off the computer")
# progress info
progress = "/var/run/unattended-upgrades.progress"
if os.path.exists(progress):
msg += "\n" + open(progress).read()
# log it
log_msg(msg)
def signal_stop_unattended_upgrade():
""" send SIGTERM to running unattended-upgrade if there is any """
pidfile = "/var/run/unattended-upgrades.pid"
if os.path.exists(pidfile):
pid = int(open(pidfile).read())
logging.debug("found running unattended-upgrades pid %s" % pid)
try:
os.kill(pid, signal.SIGTERM)
except ProcessLookupError:
logging.debug("sending SIGTERM failed because unattended-upgrades "
"already stopped")
def exit_log_result(success):
if success:
log_msg(_("All upgrades installed"), logging.INFO)
sys.exit(0)
else:
log_msg(_("Unattended-upgrades stopped. There may be upgrades"
" left to be installed in the next run."), logging.INFO)
sys.exit(1)
class UnattendedUpgradesShutdown():
def __init__(self, options):
# type: (Values) -> None
self.options = options
self.max_delay = options.delay * 60
self.iter_timer_set = False
self.apt_pkg_reinit_done = None
self.shutdown_pending = False
self.on_shutdown_mode = None
self.on_shutdown_mode_uu_proc = None
self.start_time = None
self.lock_was_taken = False
self.signal_sent = False
self.stop_signal_received = Event()
try:
hasattr(GLib, "MainLoop")
DBusGMainLoop(set_as_default=True)
except NameError:
pass
try:
self.inhibit_lock = self.get_inhibit_shutdown_lock()
except dbus.exceptions.DBusException:
logging.warning("Could not get delay inhibitor lock")
self.inhibit_lock = None
self.logind_proxy = None
self.wait_period = min(3, self.get_inhibit_max_delay() / 3)
self.preparing_for_shutdown = False
def get_logind_proxy(self):
""" Get logind dbus proxy object """
if not self.logind_proxy:
bus = dbus.SystemBus()
if self.inhibit_lock is None:
# try to get inhibit_lock or throw exception quickly when
# logind is down
self.inhibit_lock = self.get_inhibit_shutdown_lock()
self.logind_proxy = bus.get_object(
'org.freedesktop.login1', '/org/freedesktop/login1')
return self.logind_proxy
def get_inhibit_shutdown_lock(self):
""" Take delay inhibitor lock """
bus = dbus.SystemBus()
return bus.call_blocking(
'org.freedesktop.login1', '/org/freedesktop/login1',
'org.freedesktop.login1.Manager', 'Inhibit', 'ssss',
('shutdown', 'Unattended Upgrades Shutdown',
_('Stop ongoing upgrades or perform upgrades before shutdown'),
'delay'), timeout=2.0)
def get_inhibit_max_delay(self):
try:
logind_proxy = self.get_logind_proxy()
getter_interface = dbus.Interface(
logind_proxy,
dbus_interface='org.freedesktop.DBus.Properties')
return (getter_interface.Get(
"org.freedesktop.login1.Manager", "InhibitDelayMaxUSec")
/ (1000 * 1000))
except dbus.exceptions.DBusException:
return 3
def is_preparing_for_shutdown(self):
if not self.shutdown_pending:
try:
logind_proxy = self.get_logind_proxy()
getter_interface = dbus.Interface(
logind_proxy,
dbus_interface='org.freedesktop.DBus.Properties')
self.shutdown_pending = getter_interface.Get(
"org.freedesktop.login1.Manager", "PreparingForShutdown")
except dbus.exceptions.DBusException:
return False
return self.shutdown_pending
def start_iterations(self):
if not self.iter_timer_set:
try:
GLib.timeout_add(self.wait_period * 1000, self.iter)
# schedule first iteration immediately
GLib.timeout_add(0, lambda: self.iter() and False)
except NameError:
pass
def run_polling(self, signal_handler):
logging.warning(
_("Unable to monitor PrepareForShutdown() signal, polling "
"instead."))
logging.warning(
_("To enable monitoring the PrepareForShutdown() signal "
"instead of polling please install the python3-gi package"))
signal.signal(signal.SIGTERM, signal_handler)
signal.signal(signal.SIGHUP, signal_handler)
# poll for PrepareForShutdown then run final iterations
if self.options.wait_for_signal:
logging.debug("Waiting for signal to start operation ")
while (not self.stop_signal_received.is_set()
and not self.is_preparing_for_shutdown()):
self.stop_signal_received.wait(self.wait_period)
else:
logging.debug("Skip waiting for signals, starting operation "
"now")
while not self.iter():
# TODO iter on sigterm and sighup, too
time.sleep(self.wait_period)
def run(self):
""" delay shutdown and wait for PrepareForShutdown or other signals"""
# set signal handlers
def signal_handler(signum, frame):
# type: (object) -> None
logging.warning(
"SIGTERM or SIGHUP received, stopping unattended-upgrades "
"only if it is running")
self.stop_signal_received.set()
self.start_iterations()
# fall back to polling without GLib
try:
hasattr(GLib, "MainLoop")
except NameError:
self.run_polling(signal_handler)
return
for sig in (signal.SIGTERM, signal.SIGHUP):
GLib.unix_signal_add(GLib.PRIORITY_DEFAULT, sig,
signal_handler, None, None)
if self.options.wait_for_signal:
def prepare_for_shutdown_handler(active):
""" Handle PrepareForShutdown() """
if not active:
logging.warning("PrepareForShutdown(false) received, "
"this should not happen")
# PrepareForShutdown arrived, starting final iterations
self.start_iterations()
try:
self.get_logind_proxy().connect_to_signal(
"PrepareForShutdown", prepare_for_shutdown_handler)
except dbus.exceptions.DBusException:
logging.warning(
_("Unable to monitor PrepareForShutdown() signal, polling "
"instead."))
logging.warning(
_("Maybe systemd-logind service is not running."))
self.run_polling(signal_handler)
return
logging.debug("Waiting for signal to start operation ")
else:
# starting final iterations immediately
logging.debug("Skip waiting for signals, starting operation "
"now")
self.start_iterations()
GLib.MainLoop().run()
def try_iter_on_shutdown(self):
# check if we need to run unattended-upgrades on shutdown and if
# so, run it
try:
if self.apt_pkg_reinit_done is None:
logging.debug("Initializing apt_pkg configuration")
apt_pkg.init_config()
self.apt_pkg_reinit_done = True
except apt_pkg.Error as error:
# apt may be in a transient state due to unattended-upgrades
# running, thus assuming non shutdown mode is reasonable
logging.error(_("Apt returned an error thus shutdown mode is "
"disabled"))
logging.error(_("error message: '%s'"), error)
self.apt_pkg_reinit_done = False
if self.on_shutdown_mode is None:
self.on_shutdown_mode = (
not self.options.stop_only
and not self.stop_signal_received.is_set()
and self.apt_pkg_reinit_done
and apt_pkg.config.find_b(
"Unattended-Upgrade::InstallOnShutdown", False))
if self.on_shutdown_mode:
env = copy.copy(os.environ)
env["UNATTENDED_UPGRADES_FORCE_INSTALL_ON_SHUTDOWN"] = "1"
logging.debug("starting unattended-upgrades in shutdown mode")
self.on_shutdown_mode_uu_proc = subprocess.Popen(
["unattended-upgrade"], env=env)
log_msg(_("Running unattended-upgrades in shutdown mode"))
# run u-u, but switch to stopping when receiving stop signal
# because it means shutdown progressed despite holding the lock
if self.on_shutdown_mode:
log_progress()
if self.on_shutdown_mode_uu_proc.poll() is not None:
# unattended-upgrades stopped on its own
exit_log_result(True)
else:
return True
return False
def iter(self):
if self.start_time is None:
self.start_time = time.time()
logging.debug("Starting countdown of %s minutes",
self.max_delay / 60)
else:
if (time.time() - self.start_time) > self.max_delay:
logging.warning(_(
"Giving up on lockfile after %s minutes of delay"),
self.max_delay / 60)
sys.exit(1)
if not self.stop_signal_received.is_set():
if self.try_iter_on_shutdown():
return True
# run monitoring and keep "UI" updated
res = apt_pkg.get_lock(self.options.lock_file)
logging.debug("get_lock returned %i" % res)
# exit here if there is no lock
if res > 0:
logging.debug("lock not taken")
if self.lock_was_taken:
exit_log_result(self.signal_sent)
else:
sys.exit(0)
self.lock_was_taken = True
signal_stop_unattended_upgrade()
self.signal_sent = True
# show log
log_progress()
return True
def main():
# setup gettext
localesApp = "unattended-upgrades"
localesDir = "/usr/share/locale"
gettext.bindtextdomain(localesApp, localesDir)
gettext.textdomain(localesApp)
# use a normal logfile instead of syslog too as on shutdown its too
# easy to get syslog killed
logdir = "/var/log/unattended-upgrades/"
try:
apt_pkg.init_config()
logdir = apt_pkg.config.find_dir(
"Unattended-Upgrade::LogDir", logdir)
except apt_pkg.Error as error:
logging.error(_("Apt returned an error when loading configuration, "
"using default values"))
logging.error(_("error message: '%s'"), error)
parser = OptionParser()
parser.add_option("", "--debug",
action="store_true", dest="debug",
default=apt_pkg.config.find_b(
"Unattended-Upgrade::Debug", False),
help="print debug messages")
parser.add_option("", "--delay", default=25, type="int",
help="delay in minutes to wait for unattended-upgrades")
parser.add_option("", "--lock-file",
default="/var/run/unattended-upgrades.lock",
help="lock file location")
parser.add_option("", "--stop-only",
action="store_true", dest="stop_only", default=False,
help="only stop running unattended-upgrades, don't "
"start it even when "
"Unattended-Upgrade::InstallOnShutdown is true")
parser.add_option("", "--wait-for-signal",
action="store_true", dest="wait_for_signal",
default=False,
help="wait for TERM signal before starting operation")
(options, args) = parser.parse_args()
# setup logging
level = logging.INFO
if options.debug:
level = logging.DEBUG
if not os.path.exists(logdir):
os.makedirs(logdir)
logfile = os.path.join(logdir, "unattended-upgrades-shutdown.log")
logging.basicConfig(filename=logfile,
level=level,
format="%(asctime)s %(levelname)s - %(message)s")
UnattendedUpgradesShutdown(options).run()
if __name__ == "__main__":
main()