diff options
Diffstat (limited to 'cloudinit/distros/debian.py')
| -rw-r--r-- | cloudinit/distros/debian.py | 90 |
1 files changed, 84 insertions, 6 deletions
diff --git a/cloudinit/distros/debian.py b/cloudinit/distros/debian.py index f2b4dfc9..f3901470 100644 --- a/cloudinit/distros/debian.py +++ b/cloudinit/distros/debian.py @@ -7,8 +7,9 @@ # Author: Joshua Harlow <harlowja@yahoo-inc.com> # # This file is part of cloud-init. See LICENSE file for license information. - +import fcntl import os +import time from cloudinit import distros from cloudinit import helpers @@ -22,6 +23,7 @@ from cloudinit.settings import PER_INSTANCE LOG = logging.getLogger(__name__) +APT_LOCK_WAIT_TIMEOUT = 30 APT_GET_COMMAND = ('apt-get', '--option=Dpkg::Options::=--force-confold', '--option=Dpkg::options::=--force-unsafe-io', '--assume-yes', '--quiet') @@ -41,6 +43,12 @@ NETWORK_FILE_HEADER = """\ NETWORK_CONF_FN = "/etc/network/interfaces.d/50-cloud-init" LOCALE_CONF_FN = "/etc/default/locale" +APT_LOCK_FILES = [ + '/var/lib/dpkg/lock', + '/var/lib/apt/lists/lock', + '/var/cache/apt/archives/lock', +] + class Distro(distros.Distro): hostname_conf_fn = "/etc/hostname" @@ -155,7 +163,78 @@ class Distro(distros.Distro): def set_timezone(self, tz): distros.set_etc_timezone(tz=tz, tz_file=self._find_tz_file(tz)) + def _apt_lock_available(self, lock_files=None): + """Determines if another process holds any apt locks. + + If all locks are clear, return True else False. + """ + if lock_files is None: + lock_files = APT_LOCK_FILES + for lock in lock_files: + if not os.path.exists(lock): + # Only wait for lock files that already exist + continue + with open(lock, 'w') as handle: + try: + fcntl.lockf(handle, fcntl.LOCK_EX | fcntl.LOCK_NB) + except OSError: + return False + return True + + def _wait_for_apt_command( + self, short_cmd, subp_kwargs, timeout=APT_LOCK_WAIT_TIMEOUT + ): + """Wait for apt install to complete. + + short_cmd: Name of command like "upgrade" or "install" + subp_kwargs: kwargs to pass to subp + """ + start_time = time.time() + LOG.debug('Waiting for apt lock') + while time.time() - start_time < timeout: + if not self._apt_lock_available(): + time.sleep(1) + continue + LOG.debug('apt lock available') + try: + # Allow the output of this to flow outwards (not be captured) + log_msg = "apt-%s [%s]" % ( + short_cmd, + ' '.join(subp_kwargs['args']) + ) + return util.log_time( + logfunc=LOG.debug, + msg=log_msg, + func=subp.subp, + kwargs=subp_kwargs, + ) + except subp.ProcessExecutionError: + # Even though we have already waited for the apt lock to be + # available, it is possible that the lock was acquired by + # another process since the check. Since apt doesn't provide + # a meaningful error code to check and checking the error + # text is fragile and subject to internationalization, we + # can instead check the apt lock again. If the apt lock is + # still available, given the length of an average apt + # transaction, it is extremely unlikely that another process + # raced us when we tried to acquire it, so raise the apt + # error received. If the lock is unavailable, just keep waiting + if self._apt_lock_available(): + raise + LOG.debug('Another process holds apt lock. Waiting...') + time.sleep(1) + raise TimeoutError('Could not get apt lock') + def package_command(self, command, args=None, pkgs=None): + """Run the given package command. + + On Debian, this will run apt-get (unless APT_GET_COMMAND is set). + + command: The command to run, like "upgrade" or "install" + args: Arguments passed to apt itself in addition to + any specified in APT_GET_COMMAND + pkgs: Apt packages that the command will apply to + """ if pkgs is None: pkgs = [] @@ -185,11 +264,10 @@ class Distro(distros.Distro): pkglist = util.expand_package_list('%s=%s', pkgs) cmd.extend(pkglist) - # Allow the output of this to flow outwards (ie not be captured) - util.log_time(logfunc=LOG.debug, - msg="apt-%s [%s]" % (command, ' '.join(cmd)), - func=subp.subp, - args=(cmd,), kwargs={'env': e, 'capture': False}) + self._wait_for_apt_command( + short_cmd=command, + subp_kwargs={'args': cmd, 'env': e, 'capture': False} + ) def update_package_sources(self): self._runner.run("update-sources", self.package_command, |