~ubuntu-branches/ubuntu/natty/unattended-upgrades/natty

#!/usr/bin/python
# Copyright (c) 2005-2010 Canonical Ltd
#
# AUTHOR:
# Michael Vogt <mvo@ubuntu.com>
#
# 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 apt_inst
import apt_pkg

import ConfigParser
import datetime
import re
import os
import string
import sys

from StringIO import StringIO
from optparse import OptionParser
from subprocess import Popen, PIPE

import warnings
warnings.filterwarnings("ignore", "apt API not stable yet", FutureWarning)
import apt
import logging
import lsb_release
import signal
import subprocess

import gettext
from gettext import gettext as _

# the reboot required flag file used by packages
REBOOT_REQUIRED_FILE = "/var/run/reboot-required"
MAIL_BINARY = "/usr/bin/mail"
SENDMAIL_BINARY = "/usr/sbin/sendmail"
DISTRO_CODENAME = lsb_release.get_distro_information()['CODENAME']
DISTRO_ID = lsb_release.get_distro_information()['ID']

# set from the sigint signal handler
SIGNAL_STOP_REQUEST=False


class Unlocked:
    """ context manager for unlocking the apt lock while cache.commit()
        is run 
    """
    def __enter__(self):
        try:
            apt_pkg.pkgsystem_unlock()
        except:
            pass
    def __exit__(self, exc_type, exc_value, exc_tb):
        try:
            apt_pkg.pkgsystem_unlock()
        except:
            pass


def signal_handler(signal, frame):
    logging.warn("SIGUSR1 recieved, will stop")
    global SIGNAL_STOP_REQUEST
    SIGNAL_STOP_REQUEST=True

def substitute(line):
    """ substitude known mappings and return a new string 

    Currently supported ${distro-release}
    """
    mapping = {"distro_codename" : get_distro_codename(),
               "distro_id" : get_distro_id(),
              }
    return string.Template(line).substitute(mapping)
    
def get_distro_codename():
    return DISTRO_CODENAME

def get_distro_id():
    return DISTRO_ID

def get_allowed_origins_legacy():
    """ legacy support for old Allowed-Origins var """
    allowed_origins = []
    for s in apt_pkg.config.value_list("Unattended-Upgrade::Allowed-Origins"):
        # if there is a ":" use that as seperator, else use spaces
        if ":" in s:
            (distro_id, distro_codename) = s.split(':')
        else:
            (distro_id, distro_codename) = s.split()
        # convert to new format
        allowed_origins.append("o=%s,a=%s" % (substitute(distro_id), 
                                              substitute(distro_codename)))
    return allowed_origins

def get_allowed_origins():
    """ return a list of allowed origins from apt.conf

    This will take substitutions (like distro_id) into account.
    """
    allowed_origins = get_allowed_origins_legacy()
    for s in apt_pkg.config.value_list("Unattended-Upgrade::Origins-Pattern"):
        allowed_origins.append(substitute(s))
    return allowed_origins

def match_whitelist_string(whitelist, origin):
    """
    take a whitelist string in the form "origin=Debian,label=Debian-Security"
    and match against the given python-apt origin. A empty whitelist string
    never matches anything.
    """
    whitelist = whitelist.strip()
    if whitelist == "":
        logging.warn("empty match string matches nothing")
        return False
    res = True
    # make "\," the html quote equivalent
    whitelist = whitelist.replace("\,", "%2C")
    for token in whitelist.split(","):
        # strip and unquote the "," back
        (what, value) = [s.strip().replace("%2C",",")
                         for s in token.split("=")]
        #logging.debug("matching '%s'='%s' against '%s'" % (what, value, origin))
        # first char is apt-cache policy output, send is the name
        # in the Release file
        if what in ("o", "origin"):
            res &= (value == origin.origin)
        elif what in ("l", "label"):
            res &= (value == origin.label)
        elif what in ("a", "suite", "archive"):
            res &= (value == origin.archive)
        elif what in ("c", "component"):
            res &= (value == origin.component)
        elif what in ("site",):
            res &= (value == origin.site)
    return res

def upgrade_normal(cache, pkgs_to_upgrade, logfile_dpkg):
    error = None
    res = False
    try:
        with Unlocked():
            res = cache.commit()
    except SystemError,e:
        error = e
    if res:
        logging.info(_("All upgrades installed"))
    else:
        logging.error(_("Installing the upgrades failed!"))
        logging.error(_("error message: '%s'") % error)
        logging.error(_("dpkg returned a error! See '%s' for details") % \
                          logfile_dpkg)
    return res

def upgrade_in_minimal_steps(cache, pkgs_to_upgrade, logfile_dpkg=""):
    # setup signal handler
    signal.signal(signal.SIGUSR1, signal_handler)

    # to upgrade contains the package names
    to_upgrade = set(pkgs_to_upgrade)
    while True:
        # find smallest set
        smallest_partition = to_upgrade
        for pkgname in to_upgrade:
            if SIGNAL_STOP_REQUEST:
                logging.warn("SIGNAL recieved, stopping")
                return True
            pkg = cache[pkgname]
            if pkg.is_upgradable:
                pkg.mark_upgrade()
            elif not pkg.is_installed:
                pkg.mark_install()
            else:
                continue
            changes = [pkg.name for pkg in cache.get_changes()]
            if len(changes) == 1:
                logging.debug("found leaf package %s" % pkg.name)
                smallest_partition = changes
                break
            if len(changes) < len(smallest_partition):
                logging.debug("found  partition of size %s (%s)" % (len(changes), changes))
                smallest_partition = changes
            cache.clear()
        # apply changes
        logging.debug("applying set %s" % smallest_partition)
        rewind_cache(cache, [cache[name] for name in smallest_partition])
        try:
            with Unlocked():
                res = cache.commit()
                if not res:
                    raise Exception("cache.commit() returned false")
            cache.open()
        except Exception, e:
            logging.error(_("Installing the upgrades failed!"))
            logging.error(_("error message: '%s'") % e)
            logging.error(_("dpkg returned a error! See '%s' for details") % \
                              logfile_dpkg)
            return False
        to_upgrade = to_upgrade-set(smallest_partition)
        logging.debug("left to upgrade %s" % to_upgrade)
        if len(to_upgrade) == 0:
            logging.info(_("All upgrades installed"))
            break
    return True

def is_allowed_origin(pkg, allowed_origins):
    if not pkg.candidate:
        return False
    for origin in pkg.candidate.origins:
        for allowed in allowed_origins:
            if match_whitelist_string(allowed, origin):
                return True
    return False

def check_changes_for_sanity(cache, allowed_origins, blacklist):
    if cache._depcache.broken_count != 0:
        return False
    for pkg in cache:
        if pkg.marked_delete:
            logging.debug("pkg '%s' now marked delete" % pkg.name)
            return False
        if pkg.marked_install or pkg.marked_upgrade:
            if not is_allowed_origin(pkg, allowed_origins):
                logging.debug("pkg '%s' not in allowed origin" % pkg.name)
                return False
            for blacklist_regexp in blacklist:
                if re.match(blacklist_regexp, pkg.name):
                    logging.debug("pkg '%s' blacklisted" % pkg.name)
                    return False
            if pkg._pkg.selected_state == apt_pkg.SELSTATE_HOLD:
                logging.debug("pkg '%s' is on hold" % pkg.name)
                return False
    return True

def pkgname_from_deb(debfile):
    # FIXME: add error checking here
    try:
        control = apt_inst.DebFile(debfile).control.extractdata("control")
        sections = apt_pkg.TagSection(control)
        return sections["Package"]
    except (IOError, SystemError), e:
        logging.error("failed to read deb file '%s' (%s)" % (debfile, e))
        # dumb fallback
        return debfile.split("_")[0]

# prefix is *only* needed for the build-in tests
def conffile_prompt(destFile, prefix=""):
    logging.debug("check_conffile_prompt('%s')" % destFile)
    pkgname = pkgname_from_deb(destFile)
    status_file = apt_pkg.config.find("Dir::State::status")
    tagfile = apt_pkg.TagFile(open(status_file,"r"))
    for section in tagfile:
        if section.get("Package") == pkgname:
            logging.debug("found pkg: %s" % pkgname)
            if "Conffiles" in section:
                conffiles = section.get("Conffiles")
                # Conffiles:
                # /etc/bash_completion.d/m-a c7780fab6b14d75ca54e11e992a6c11c
                for line in string.split(conffiles,"\n"):
                    logging.debug("conffile line: %s", line)
                    l = string.split(string.strip(line))
                    conf_file = l[0]
                    md5 = l[1]
                    if len(l) > 2:
                        obs = l[2]
                    else:
                        obs = None
                    # ignore if conffile is obsolete or does not exist
                    if obs == "obsolete" or not os.path.exists(prefix+conf_file):
                        continue
                    # get conffile value from pkg
                    pkg_conffiles = apt_inst.debExtractControl(
                        open(destFile), "conffiles")
                    if (not pkg_conffiles or 
                        not conf_file in pkg_conffiles.split("\n")):
                        logging.debug("'%s' not in package conffiles '%s'" % (conf_file, pkg_conffiles))
                        continue
                    # test against the installed file
                    current_md5 = apt_pkg.md5sum(open(prefix+conf_file).read())
                    logging.debug("current md5: %s" % current_md5)
                    # hashes are the same, no conffile prompt
                    if current_md5 == md5:
                        return False
                    # calculate md5sum from the deb (may take a bit)
                    dpkg_cmd = ["dpkg-deb","--fsys-tarfile",destFile]
                    tar_cmd = ["tar","-x","-O", "-f","-", "."+conf_file]
                    md5_cmd = ["md5sum"]
                    dpkg_p = Popen(dpkg_cmd, stdout=PIPE)
                    tar_p = Popen(tar_cmd, stdin=dpkg_p.stdout, stdout=PIPE)
                    md5_p = Popen(md5_cmd, stdin=tar_p.stdout, stdout=PIPE)
                    pkg_md5sum = md5_p.communicate()[0].split()[0]
                    logging.debug("pkg_md5sum: %s" % pkg_md5sum)
                    # the md5sum in the deb is unchanged, this will not 
                    # trigger a conffile prompt
                    if pkg_md5sum == md5:
                        continue
                    # if we made it to this point:
                    #  current_md5 != pkg_md5sum != md5
                    # and that will trigger a conffile prompt, we can
                    # stop processing at this point and just return True
                    return True
    return False


def dpkg_conffile_prompt():
    if not "DPkg::Options" in apt_pkg.config:
        return True
    options = apt_pkg.config.value_list("DPkg::Options")
    for option in map(string.strip, options):
        if (option == "--force-confold" or
	    option == "--force-confnew"):
            return False
    return True

def rewind_cache(cache, pkgs_to_upgrade):
    " set the cache back to the state with packages_to_upgrade "
    cache.clear()
    for pkg2 in pkgs_to_upgrade:
        pkg2.mark_upgrade()

def host():
    return os.uname()[1]

# *sigh* textwrap is nice, but it breaks "linux-image" into two
# seperate lines
def wrap(t, width=70, subsequent_indent=""):
    out = ""
    for s in t.split():
        if (len(out)-out.rfind("\n")) + len(s) > width:
            out += "\n" + subsequent_indent
        out += s + " "
    return out

def setup_apt_listchanges(conf="/etc/apt/listchanges.conf"):
    """ deal with apt-listchanges """
    if os.path.exists(conf):
        # check if mail is used by apt-listchanges
        cf = ConfigParser.ConfigParser()
        cf.read(conf)
        if cf.has_section("apt") and cf.has_option("apt", "frontend"):
            frontend = cf.get("apt","frontend")
            if frontend == "mail" and os.path.exists(SENDMAIL_BINARY):
                # mail frontend and sendmail, we are fine
                logging.debug("apt-listchanges is set to mail frontend, ignoring")
                return
    # setup env (to play it safe) and return
    os.environ["APT_LISTCHANGES_FRONTEND"] = "none"

def send_summary_mail(pkgs, res, pkgs_kept_back, mem_log, logfile_dpkg):
    " send mail (if configured in Unattended-Upgrades::Mail) "
    email = apt_pkg.config.find("Unattended-Upgrade::Mail", "")
    if not email:
        return
    if not os.path.exists(MAIL_BINARY):
        logging.error(_("No '/usr/bin/mail', can not send mail. "
                        "You probably want to install the 'mailx' package."))
        return
    # if the operation was successful and the user has requested to get
    # mails on on errors, just exit here
    if (res and
        apt_pkg.config.find_b("Unattended-Upgrade::MailOnlyOnError", False)):
	return
    # Check if reboot-required flag is present
    logging.debug("Sending mail with '%s' to '%s'" % (logfile_dpkg, email))
    if os.path.isfile(REBOOT_REQUIRED_FILE):
        subject = _("[reboot required] unattended-upgrades result for '%s'") % host()
    else:
        subject = _("unattended-upgrades result for '%s'") % host()
    mail = subprocess.Popen([MAIL_BINARY, "-s", subject,
                             email], stdin=subprocess.PIPE)
    s = _("Unattended upgrade returned: %s\n\n") % res
    if os.path.isfile(REBOOT_REQUIRED_FILE):
        s += _("Warning: A reboot is required to complete this upgrade.\n\n")
    s += _("Packages that are upgraded:\n")
    s += " " + wrap(pkgs, 70, " ")
    s += "\n"
    if pkgs_kept_back:
        s += _("Packages with upgradable origin but kept back:\n")
        s += " " + wrap(" ".join(pkgs_kept_back), 70, " ")
        s += "\n"
    s += "\n"
    s += _("Package installation log:")+"\n"
    s += open(logfile_dpkg).read()
    s += "\n\n"
    s += _("Unattended-upgrades log:\n")
    s += mem_log.getvalue()
    mail.stdin.write(s)
    mail.stdin.close()
    ret = mail.wait()
    logging.debug("mail returned: %s" % ret)
    

def _setup_alternative_rootdir(rootdir):
    # clear system unattended-upgrade stuff
    apt_pkg.config.clear("Unattended-Upgrade")
    # read rootdir (taken from apt.Cache, but we need to run it
    # here before the cache gets initialized
    if os.path.exists(rootdir+"/etc/apt/apt.conf"):
        apt_pkg.read_config_file(apt_pkg.config,
                                 rootdir + "/etc/apt/apt.conf")
    if os.path.isdir(rootdir+"/etc/apt/apt.conf.d"):
        apt_pkg.read_config_dir(apt_pkg.config,
                                rootdir + "/etc/apt/apt.conf.d")

def _get_logdir():
    logdir= apt_pkg.config.find_dir(
        "Unattended-Upgrade::LogDir",
        # COMPAT only
        apt_pkg.config.find_dir("APT::UnattendedUpgrades::LogDir",
                                "/var/log/unattended-upgrades/"))
    return logdir

def _setup_logging(options):
    # init the logging
    logdir = _get_logdir()
    logfile = os.path.join(
        logdir,
        apt_pkg.config.find(
            "Unattended-Upgrade::LogFile",
            # COMPAT only
            apt_pkg.config.find("APT::UnattendedUpgrades::LogFile",
                                "unattended-upgrades.log")))

    if not options.dry_run and not os.path.exists(os.path.dirname(logfile)):
        os.makedirs(os.path.dirname(logfile))

    logging.basicConfig(level=logging.INFO,
                        format='%(asctime)s %(levelname)s %(message)s',
                        filename=logfile)


def main(options, rootdir=""):

    # useful for testing
    if rootdir:
        _setup_alternative_rootdir(rootdir)

    _setup_logging(options)

    # setup logging
    logger = logging.getLogger()
    mem_log = StringIO()
    if options.debug:
        logger.setLevel(logging.DEBUG)
        stderr_handler = logging.StreamHandler()
        logger.addHandler(stderr_handler)
    if apt_pkg.config.find("Unattended-Upgrade::Mail", ""):
        mem_log_handler = logging.StreamHandler(mem_log)
        logger.addHandler(mem_log_handler)

    # format (origin, archive), e.g. ("Ubuntu","dapper-security")
    allowed_origins = get_allowed_origins()

    # pkgs that are (for some reason) not save to install
    blacklisted_pkgs = apt_pkg.config.value_list("Unattended-Upgrade::Package-Blacklist")
    logging.info(_("Initial blacklisted packages: %s"), " ".join(blacklisted_pkgs))
    logging.info(_("Starting unattended upgrades script"))

    # display available origin
    logging.info(_("Allowed origins are: %s") % map(str,allowed_origins))
    
    # check and get lock
    try:
        apt_pkg.pkgsystem_lock()
    except SystemError, e:
        logging.error(_("Lock could not be acquired (another package "
                        "manager running?)"))
        print _("Cache lock can not be acquired, exiting")
        sys.exit(1)

    # get a cache
    cache = apt.Cache(rootdir=rootdir)
    if cache._depcache.broken_count > 0:
        print _("Cache has broken packages, exiting")
        logging.error(_("Cache has broken packages, exiting"))
        sys.exit(1)
    # speed things up with latest apt
    actiongroup = apt_pkg.ActionGroup(cache._depcache)

    # find out about the packages that are upgradable (in a allowed_origin)
    pkgs_to_upgrade = []
    pkgs_kept_back = []
    pkgs_auto_removable = set([pkg.name for pkg in cache 
                               if pkg.is_auto_removable])
    for pkg in cache:
        if options.debug and pkg.is_upgradable:
            logging.debug("Checking: %s (%s)" % (pkg.name, map(str, pkg.candidate.origins)))
        if (pkg.is_upgradable and 
	    is_allowed_origin(pkg,allowed_origins)):
            try:
                pkg.mark_upgrade()
                if check_changes_for_sanity(cache, allowed_origins,
                                            blacklisted_pkgs):
                    pkgs_to_upgrade.append(pkg)
                else:
                    logging.debug("sanity check failed")
                    rewind_cache(cache, pkgs_to_upgrade)
                    pkgs_kept_back.append(pkg.name)
            except SystemError, e:
                # can't upgrade
                logging.warning(_("package '%s' upgradable but fails to be marked for upgrade (%s)") % (pkg.name, e))
                rewind_cache(cache, pkgs_to_upgrade)
                pkgs_kept_back.append(pkg.name)
                

    pkgs = "\n".join([pkg.name for pkg in pkgs_to_upgrade])
    logging.debug("pkgs that look like they should be upgraded: %s" % pkgs)
           
    # download what looks good
    if options.debug:
        fetcher = apt_pkg.Acquire(apt.progress.text.AcquireProgress())
    else:
        fetcher = apt_pkg.Acquire()
    list = apt_pkg.SourceList()
    list.read_main_list()
    recs = cache._records
    pm = apt_pkg.PackageManager(cache._depcache)
    try:
        pm.get_archives(fetcher,list,recs)
    except SystemError, e:
        logging.error(_("GetArchives() failed: '%s'") % e)
    res = fetcher.run()

    if dpkg_conffile_prompt():
        # now check the downloaded debs for conffile conflicts and build
        # a blacklist
        for item in fetcher.items:
            logging.debug("%s" % item)
            if item.status == item.STAT_ERROR:
                print _("An error ocured: '%s'") % item.error_text
                logging.error(_("An error ocured: '%s'") % item.error_text)
            if not item.complete:
                print _("The URI '%s' failed to download, aborting") % item.desc_uri
                logging.error(_("The URI '%s' failed to download, aborting") % item.desc_uri)
                sys.exit(1)
            if not os.path.exists(item.destfile):
                print _("Download finished, but file '%s' not there?!?" % item.destfile)
                logging.error("Download finished, but file '%s' not there?!?" % item.destfile)
                sys.exit(1)
            if not item.is_trusted:
                blacklisted_pkgs.append(pkgname_from_deb(item.destfile))
            if conffile_prompt(item.destfile):
                # FIXME: skip package (means to re-run the whole marking again
                # and making sure that the package will not be pulled in by
                # some other package again!
                logging.warning(_("Package '%s' has conffile prompt and needs to be upgraded manually") % pkgname_from_deb(item.destfile))
                blacklisted_pkgs.append(pkgname_from_deb(item.destfile))
                pkgs_kept_back.append(pkgname_from_deb(item.destfile))


        # redo the selection about the packages to upgrade based on the new
        # blacklist
        logging.debug("blacklist: %s" % blacklisted_pkgs)
        # find out about the packages that are upgradable (in a allowed_origin)
        if len(blacklisted_pkgs) > 0:
            cache.clear()
            old_pkgs_to_upgrade = pkgs_to_upgrade[:]
            pkgs_to_upgrade = []
            for pkg in old_pkgs_to_upgrade:
                logging.debug("Checking (blacklist): %s" % (pkg.name))
                pkg.mark_upgrade()
                if check_changes_for_sanity(cache, allowed_origins,
                                            blacklisted_pkgs):
                     pkgs_to_upgrade.append(pkg)
                else:
                    if not (pkg.name in pkgs_kept_back):
                        pkgs_kept_back.append(pkg.name)
                    logging.info(_("package '%s' not upgraded") % pkg.name)
                    cache.clear()
                    for pkg2 in pkgs_to_upgrade:
                        pkg2.mark_upgrade()
    else:
        logging.debug("dpkg is configured not to cause conffile prompts")

    # do auto-remove
    if apt_pkg.config.find_b("Unattended-Upgrade::Remove-Unused-Dependencies", False):
        now_auto_removable = set([pkg.name for pkg in cache 
                               if pkg.is_auto_removable])
        for pkgname in now_auto_removable-pkgs_auto_removable:
            logging.debug("marking %s for remove" % pkgname)
            cache[pkgname].mark_delete()
        logging.info(_("Packages that are auto removed: '%s'") %
                     " ".join(now_auto_removable-pkgs_auto_removable))

    logging.debug("InstCount=%i DelCount=%i BrokenCout=%i" % (cache._depcache.inst_count, cache._depcache.del_count, cache._depcache.broken_count))

    # exit if there is nothing to do and nothing to report
    if (len(pkgs_to_upgrade) == 0) and (len(pkgs_kept_back) == 0):
        logging.info(_("No packages found that can be upgraded unattended"))
        return

    # check if we are in dry-run mode
    if options.dry_run:
        logging.info("Option --dry-run given, *not* performing real actions")
        apt_pkg.config.set("Debug::pkgDPkgPM","1")

    # do the install based on the new list of pkgs
    pkgs = " ".join([pkg.name for pkg in pkgs_to_upgrade])
    logging.info(_("Packages that are upgraded: %s" % pkgs))

    # set debconf to NON_INTERACTIVE, redirect output
    os.putenv("DEBIAN_FRONTEND","noninteractive");
    setup_apt_listchanges()
    
    # redirect to log
    REDIRECT_INPUT = os.devnull
    fd = os.open(REDIRECT_INPUT, os.O_RDWR)
    os.dup2(fd,0)

    now = datetime.datetime.now()
    logfile_dpkg = os.path.join(
        _get_logdir(), 'unattended-upgrades-dpkg_%s.log' % now.isoformat('_'))
    logging.info(_("Writing dpkg log to '%s'") % logfile_dpkg)
    fd = os.open(logfile_dpkg, os.O_RDWR|os.O_CREAT, 0644)
    old_stdout = os.dup(1)
    old_stderr = os.dup(2)
    os.dup2(fd,1)
    os.dup2(fd,2)

    try:
        # lock for the shutdown check - its fine if the system
        # is shutdown while downloading but not so much while installing
        apt_pkg.get_lock("/var/run/unattended-upgrades.lock")

        if (options.minimal_upgrade_steps or 
            apt_pkg.config.find_b("Unattended-Upgrades::MinimalSteps", False)):
            open("/var/run/unattended-upgrades.pid", "w").write("%s" % os.getpid())
            # try upgrade all "pkgs" in minimal steps
            pkg_install_success = upgrade_in_minimal_steps(
                cache, [pkg.name for pkg in pkgs_to_upgrade], logfile_dpkg)
        else:
            pkg_install_success = upgrade_normal(
                cache, [pkg.name for pkg in pkgs_to_upgrade], logfile_dpkg)
    except Exception, e:
        # print unhandled exceptions here this way, while stderr is redirected
        os.write(old_stderr, "Exception: %s" % e)

    # restore
    os.dup2(old_stdout, 1)
    os.dup2(old_stderr, 2)

    # send a mail (if needed)
    if not options.dry_run:
        send_summary_mail(
            pkgs, pkg_install_success, pkgs_kept_back, mem_log, logfile_dpkg)

    # auto-reboot (if required and the config for this is set
    if (apt_pkg.config.find_b("Unattended-Upgrade::Automatic-Reboot", False) and
        os.path.exists(REBOOT_REQUIRED_FILE)):
        logging.warning("Found %s, rebooting" % REBOOT_REQUIRED_FILE)
        subprocess.call(["/sbin/reboot"])
        

if __name__ == "__main__":
    localesApp="unattended-upgrades"
    localesDir="/usr/share/locale"
    gettext.bindtextdomain(localesApp, localesDir)
    gettext.textdomain(localesApp)

    # init the options
    parser = OptionParser()
    parser.add_option("-d", "--debug",
                      action="store_true", dest="debug", default=False,
                      help=_("print debug messages"))
    parser.add_option("", "--dry-run",
                      action="store_true", default=False,
                      help=_("Simulation, download but do not install"))
    parser.add_option("", "--minimal_upgrade_steps",
                      action="store_true", default=False,
                      help=_("Upgrade in minimal steps (and allow interrupting with SIGINT"))
    (options, args) = parser.parse_args()

    if os.getuid() != 0:
        print _("You need to be root to run this application")
        sys.exit(1)

    # nice & ionce
    os.nice(19)
    subprocess.call(["ionice","-c3", "-p",str(os.getpid())])

    # run the main code
    main(options)