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Diffstat (limited to 'cloudinit/config/cc_ubuntu_init_switch.py')
| -rw-r--r-- | cloudinit/config/cc_ubuntu_init_switch.py | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/cloudinit/config/cc_ubuntu_init_switch.py b/cloudinit/config/cc_ubuntu_init_switch.py new file mode 100644 index 00000000..485c46a4 --- /dev/null +++ b/cloudinit/config/cc_ubuntu_init_switch.py @@ -0,0 +1,150 @@ +# vi: ts=4 expandtab +# +# Copyright (C) 2014 Canonical Ltd. +# +# Author: Scott Moser <scott.moser@canonical.com> +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License version 3, as +# published by the Free Software Foundation. +# +# This program 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 this program. If not, see <http://www.gnu.org/licenses/>. + +""" +ubuntu_init_switch: reboot system into another init + +This provides a way for the user to boot with systemd even if the +image is set to boot with upstart. It should be run as one of the first +cloud_init_modules, and will switch the init system and then issue a reboot. +The next boot will come up in the target init system and no action will +be taken. + +This should be inert on non-ubuntu systems, and also exit quickly. + +config is comes under the top level 'init_switch' dictionary. + +#cloud-config +init_switch: + target: systemd + +'target' can be 'systemd' or 'upstart'. Best effort is made, but its possible +this system will break, and probably won't interact well with any other +mechanism you've used to switch the init system. +""" + +from cloudinit.settings import PER_INSTANCE +from cloudinit import log as logging +from cloudinit import util +from cloudinit.distros import ubuntu + +import os +import time + +frequency = PER_INSTANCE +REBOOT_CMD = ["/sbin/reboot"] + +DEFAULT_CONFIG = { + 'init_switch': {'target': None} +} + +SWITCH_INIT = """ +#!/bin/sh +# switch_init: [upstart | systemd] + +is_systemd() { + [ "$(dpkg-divert --listpackage /sbin/init)" = "systemd-sysv" ] +} +debug() { echo "$@" 1>&2; } +fail() { echo "$@" 1>&2; exit 1; } + +if [ "$1" = "systemd" ]; then + if is_systemd; then + debug "already systemd, nothing to do" + else + [ -f /lib/systemd/systemd ] || fail "no systemd available"; + dpkg-divert --package systemd-sysv --divert /sbin/init.diverted \\ + --rename /sbin/init + fi + [ -f /sbin/init ] || ln /lib/systemd/systemd /sbin/init +elif [ "$1" = "upstart" ]; then + if is_systemd; then + rm -f /sbin/init + dpkg-divert --package systemd-sysv --rename --remove /sbin/init + else + debug "already upstart, nothing to do." + fi +else + fail "Error. expect 'upstart' or 'systemd'" +fi +""" + + +def handle(name, cfg, cloud, log, args): + + if not isinstance(cloud.distro, ubuntu.Distro): + log.debug("%s: distro is '%s', not ubuntu. returning", + name, cloud.distro.__class__) + return + + cfg = util.mergemanydict([cfg, DEFAULT_CONFIG]) + target = cfg['init_switch']['target'] + + if len(args) != 0: + target = args[0] + + if not target: + log.debug("%s: target=%s. nothing to do", name, target) + return + + if not util.which('dpkg'): + log.warn("%s: 'dpkg' not available. Assuming not ubuntu", name) + return + + supported = ('upstart', 'systemd') + if target not in supported: + log.warn("%s: target set to %s, expected one of: %s", + name, target, str(supported)) + + if os.path.exists("/run/systemd"): + current = "systemd" + else: + current = "upstart" + + if current == target: + log.debug("%s: current = target = %s. nothing to do", name, target) + return + + try: + util.subp(['sh', '-c', SWITCH_INIT, '--', target]) + except util.ProcessExecutionError as e: + log.warn("%s: Failed to switch to init '%s'. %s", name, target, e) + return + + try: + log.warn("%s: rebooting from '%s' to '%s'", name, current, target) + logging.flushLoggers(log) + _fire_reboot(log, initial_sleep=4) + except Exception as e: + util.logexc(log, "Requested reboot did not happen!") + raise + + +def _fire_reboot(log, wait_attempts=6, initial_sleep=1, backoff=2): + util.subp(REBOOT_CMD) + start = time.time() + wait_time = initial_sleep + for _i in range(0, wait_attempts): + time.sleep(wait_time) + wait_time *= backoff + elapsed = time.time() - start + log.debug("Rebooted, but still running after %s seconds", int(elapsed)) + # If we got here, not good + elapsed = time.time() - start + raise RuntimeError(("Reboot did not happen" + " after %s seconds!") % (int(elapsed))) |