# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

description     "D-Bus message bus daemon"
author          "chromium-os-dev@chromium.org"

# Stop conditions for this job deliberately omitted: D-Bus clients
# routinely terminate with crashes when dbus-daemon terminates before
# them. Ordering process termination with Upstart is hard, so we simply
# leave dbus-daemon running to ensure the rest of the system can shut
# down cleanly. Also see the post-stop script below that reboots the
# system in response to dbus-daemon exiting unexpectedly.
start on starting boot-services

pre-start script
  mkdir -p /run/dbus
  chown messagebus:messagebus /run/dbus
  mkdir -p /var/lib/dbus

  # The following ensures that there is a valid machine-id for dbus and
  # that it's regenerated on every boot to avoid potential privacy
  # issues.
  rm -f /var/lib/dbus/machine-id
  dbus-uuidgen --ensure
end script

expect fork
exec dbus-daemon --system --fork

# Instruct Upstart to establish a connection to the System Bus so that
# dbus-send can be used to communicate with it.
post-start exec kill -USR1 1

post-stop script
  # The system is unusable if dbus-daemon crashes; the various daemons
  # that were connected to it won't re-register their service names, so
  # they won't be able to talk to each other. Instead of attempting to
  # respawn dbus-daemon, reboot the system to get back to a sane state.
  logger -t "$UPSTART_JOB" "dbus-daemon exited unexpectedly; rebooting"
  uptime_sec=$(awk '{ print $1 }' </proc/uptime)
  metrics_client -t Uptime.DBusCrash "${uptime_sec}" 1 1000000 50
  reboot
end script