nixpkgs/modules/system/activation/switch-to-configuration.sh
2012-07-25 11:30:16 -04:00

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#! @shell@
set -e
export PATH=/empty
for i in @path@; do PATH=$PATH:$i/bin:$i/sbin; done
action="$1"
if ! test -e /etc/NIXOS; then
echo "This is not a NixOS installation (/etc/NIXOS) is missing!"
exit 1
fi
if test -z "$action"; then
cat <<EOF
Usage: $0 [switch|boot|test]
switch: make the configuration the boot default and activate now
boot: make the configuration the boot default
test: activate the configuration, but don't make it the boot default
EOF
exit 1
fi
# Install or update the bootloader.
if [ "$action" = "switch" -o "$action" = "boot" ]; then
@installBootLoader@ @out@
fi
# Activate the new configuration.
if [ "$action" != switch -a "$action" != test ]; then exit 0; fi
oldVersion=$(cat /run/current-system/upstart-interface-version 2> /dev/null || echo 0)
newVersion=$(cat @out@/upstart-interface-version 2> /dev/null || echo 0)
if test "$oldVersion" -ne "$newVersion"; then
cat <<EOF
Warning: the new NixOS configuration has an Upstart version that is
incompatible with the current version. The new configuration won't
take effect until you reboot the system.
EOF
exit 1
fi
# Ignore SIGHUP so that we're not killed if we're running on (say)
# virtual console 1 and we restart the "tty1" job.
trap "" SIGHUP
jobsDir=$(readlink -f @out@/etc/init)
# Stop all currently running jobs that are not in the new Upstart
# configuration. (Here "running" means all jobs that are not in the
# stop/waiting state.)
for job in $(initctl list | sed -e '/ stop\/waiting/ d; /^[^a-z]/ d; s/^\([^ ]\+\).*/\1/' | sort); do
if ! [ -e "$jobsDir/$job.conf" ] ; then
echo "stopping obsolete job $job..."
stop --quiet "$job" || true
fi
done
# Activate the new configuration (i.e., update /etc, make accounts,
# and so on).
echo "activating the configuration..."
@out@/activate @out@
# Make Upstart reload its jobs.
initctl reload-configuration
# Allow Upstart jobs to react intelligently to a config change.
initctl emit config-changed
declare -A tasks=(@tasks@)
declare -A noRestartIfChanged=(@noRestartIfChanged@)
start_() {
local job="$1"
if start --quiet "$job"; then
# Handle services that cancel themselves.
if ! [ -n "${tasks[$job]}" ]; then
local status=$(status "$job")
[[ "$status" =~ start/running ]] || echo "job $job failed to start!"
fi
fi
}
log() {
echo "$@" >&2 || true
}
# Restart all running jobs that have changed. (Here "running" means
# all jobs that don't have a "stop" goal.) We use the symlinks in
# /var/run/upstart-jobs (created by each job's pre-start script) to
# determine if a job has changed.
for job in @jobs@; do
status=$(status "$job")
if ! [[ "$status" =~ start/ ]]; then continue; fi
if [ "$(readlink -f "$jobsDir/$job.conf")" = "$(readlink -f "/var/run/upstart-jobs/$job")" ]; then continue; fi
if [ -n "${noRestartIfChanged[$job]}" ]; then
log "not restarting changed service $job"
continue
fi
log "restarting changed service $job..."
# Note: can't use "restart" here, since that only restarts the
# job's main process.
stop --quiet "$job" || true
start_ "$job" || true
done
# Start all jobs that are not running but should be. The "should be"
# criterion is tricky: the intended semantics is that we end up with
# the same jobs as after a reboot. If it's a task, start it if it
# differs from the previous instance of the same task; if it wasn't
# previously run, don't run it. If it's a service, only start it if
# it has a "start on" condition.
for job in @jobs@; do
status=$(status "$job")
if ! [[ "$status" =~ stop/ ]]; then continue; fi
if [ -n "${tasks[$job]}" ]; then
if [ ! -e "/var/run/upstart-jobs/$job" -o \
"$(readlink -f "$jobsDir/$job.conf")" = "$(readlink -f "/var/run/upstart-jobs/$job")" ];
then continue; fi
if [ -n "${noRestartIfChanged[$job]}" ]; then continue; fi
log "starting task $job..."
start --quiet "$job" || true
else
if ! grep -q "^start on" "$jobsDir/$job.conf"; then continue; fi
log "starting service $job..."
start_ "$job" || true
fi
done
# Signal dbus to reload its configuration.
dbusPid=$(initctl status dbus 2> /dev/null | sed -e 's/.*process \([0-9]\+\)/\1/;t;d')
[ -n "$dbusPid" ] && kill -HUP "$dbusPid"