#!/bin/sh
### BEGIN INIT INFO
# Provides:          clickhouse-server
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Required-Start:
# Required-Stop:
# Short-Description: Yandex clickhouse-server daemon
### END INIT INFO


CLICKHOUSE_USER=clickhouse
CLICKHOUSE_GROUP=${CLICKHOUSE_USER}
SHELL=/bin/bash
PROGRAM=clickhouse-server
SYSCONFDIR=/etc/$PROGRAM
CLICKHOUSE_LOGDIR=/var/log/clickhouse-server
CLICKHOUSE_LOGDIR_USER=root
CLICKHOUSE_DATADIR=/var/lib/$CLICKHOUSE_USER
CLICKHOUSE_DATADIR_OLD=/opt/clickhouse
LOCALSTATEDIR=/var/lock
BINDIR=/usr/bin
CLICKHOUSE_CRONFILE=/etc/cron.d/clickhouse-server
CLICKHOUSE_CONFIG=$SYSCONFDIR/config.xml
LOCKFILE=$LOCALSTATEDIR/$PROGRAM
RETVAL=0

CLICKHOUSE_PIDDIR=/var/run/$PROGRAM
CLICKHOUSE_PIDFILE="$CLICKHOUSE_PIDDIR/$PROGRAM.pid"

# Override defaults from optional config file
test -f /etc/default/clickhouse && . /etc/default/clickhouse

# On x86_64, check for required instruction set.
if uname -mpi | grep -q 'x86_64'; then
	if ! grep -q 'sse4_2' /proc/cpuinfo; then
		# On KVM, cpuinfo could falsely not report SSE 4.2 support, so skip the check.
		if ! grep -q 'Common KVM processor' /proc/cpuinfo; then

		    # Some other VMs also report wrong flags in cpuinfo.
			# Tricky way to test for instruction set:
			#  create temporary binary and run it;
			#  if it get caught illegal instruction signal,
			#  then required instruction set is not supported really.
			#
			# Generated this way:
			# gcc -xc -Os -static -nostdlib - <<< 'void _start() { __asm__("pcmpgtq %%xmm0, %%xmm1; mov $0x3c, %%rax; xor %%rdi, %%rdi; syscall":::"memory"); }' && strip -R .note.gnu.build-id -R .comment -R .eh_frame -s ./a.out && gzip -c -9 ./a.out | base64 -w0; echo

			if ! (echo -n 'H4sICAwAW1cCA2Eub3V0AKt39XFjYmRkgAEmBjsGEI+H0QHMd4CKGyCUAMUsGJiBJDNQNUiYlQEZOKDQclB9cnD9CmCSBYqJBRxQOvBpSQobGfqIAWn8FuYnPI4fsAGyPQz/87MeZtArziguKSpJTGLQK0mtKGGgGHADMSgoYH6AhTMPNHyE0NQzYuEzYzEXFr6CBPQDANAsXKTwAQAA' | base64 -d | gzip -d > /tmp/clickhouse_test_sse42 && chmod a+x /tmp/clickhouse_test_sse42 && /tmp/clickhouse_test_sse42); then
				echo 'Warning! SSE 4.2 instruction set is not supported'
				#exit 3
			fi
		fi
	fi
fi

SUPPORTED_COMMANDS="{start|stop|status|restart|forcestop|forcerestart|reload|condstart|condstop|condrestart|condreload|initdb}"
is_supported_command()
{
	echo $SUPPORTED_COMMANDS | grep -E "(\{|\|)$1(\||})" &> /dev/null
}

generate_program_name()
{
	echo $PROGRAM
}

generate_pid_name()
{
	echo $CLICKHOUSE_PIDFILE
}

specific_log_file_for_each_process()
{
	echo ""
}

is_running()
{
	pidfile=$1

	[ -r $pidfile ] && pgrep -s $(cat "$pidfile") 1> /dev/null 2> /dev/null
}

running_processes()
{
	running=0
	if is_running $CLICKHOUSE_PIDFILE; then
		running=$(($running + 1))
	fi
	echo $running
}

any_runs()
{
	if [ $(running_processes) -gt 0 ]; then return 0; else return 1; fi
}

all_runs()
{
	[ $(running_processes) -eq 1 ]
}

wait4done()
{
	while any_runs; do
		sleep 1
	done
}


initdb()
{
	if ! getent group ${CLICKHOUSE_USER} >/dev/null; then
		echo "Can't chown to non-existing user ${CLICKHOUSE_USER}"
		return
	fi
	if ! getent passwd ${CLICKHOUSE_GROUP} >/dev/null; then
		echo "Can't chown to non-existing group ${CLICKHOUSE_GROUP}"
		return
	fi

	if ! `su -s $SHELL ${CLICKHOUSE_USER} -c "test -r ${CLICKHOUSE_CONFIG}"`; then
		echo "Warning! clickhouse config [${CLICKHOUSE_CONFIG}] not readable by user [${CLICKHOUSE_USER}]"
	fi

	if ! `su -s $SHELL ${CLICKHOUSE_USER} -c "test -O ${CLICKHOUSE_DATADIR} && test -G ${CLICKHOUSE_DATADIR}"`; then
		echo "Changing owner of [${CLICKHOUSE_DATADIR}] to [${CLICKHOUSE_USER}:${CLICKHOUSE_GROUP}]"
		chown -R ${CLICKHOUSE_USER}:${CLICKHOUSE_GROUP} ${CLICKHOUSE_DATADIR}
	fi

	if ! `su -s $SHELL ${CLICKHOUSE_USER} -c "test -w ${CLICKHOUSE_LOGDIR}"`; then
		echo "Changing owner of [${CLICKHOUSE_LOGDIR}/*] to [${CLICKHOUSE_USER}:${CLICKHOUSE_GROUP}]"
		chown -R ${CLICKHOUSE_USER}:${CLICKHOUSE_GROUP} ${CLICKHOUSE_LOGDIR}/*
		echo "Changing owner of [${CLICKHOUSE_LOGDIR}] to [${CLICKHOUSE_LOGDIR_USER}:${CLICKHOUSE_GROUP}]"
		chown ${CLICKHOUSE_LOGDIR_USER}:${CLICKHOUSE_GROUP} ${CLICKHOUSE_LOGDIR}
	fi

	# Temporary fix for old metrika user, remove after 2017-06-01
	if [ ! -z ${CLICKHOUSE_DATADIR_OLD} ] && [ -d ${CLICKHOUSE_DATADIR_OLD} ] && ! `su -s $SHELL ${CLICKHOUSE_USER} -c "test -w ${CLICKHOUSE_DATADIR_OLD}"` ; then
		echo "Changing owner of old [${CLICKHOUSE_DATADIR_OLD}] to [${CLICKHOUSE_USER}:${CLICKHOUSE_GROUP}]"
		chown -R ${CLICKHOUSE_USER}:${CLICKHOUSE_GROUP} ${CLICKHOUSE_DATADIR_OLD}
	fi
}

start()
{
	[ -x $BINDIR/$PROGRAM ] || exit 0
	local EXIT_STATUS
	EXIT_STATUS=0

	echo -n "Start $PROGRAM service: "
	ulimit -n 262144

	if all_runs; then
		echo -n "already running "
		EXIT_STATUS=1
	else
		mkdir -p $CLICKHOUSE_PIDDIR
		chown -R $CLICKHOUSE_USER:$CLICKHOUSE_GROUP $CLICKHOUSE_PIDDIR
		initdb
			if ! is_running $CLICKHOUSE_PIDFILE; then
				rm -f $CLICKHOUSE_PIDFILE
				# чтобы лок не удерживался в течении времени жизни дочернего процесса, освободим лок
				su -l $CLICKHOUSE_USER -s $SHELL -c "flock -u 9; exec -a $(generate_program_name $i) \"$BINDIR/$PROGRAM\" --daemon --pid-file=\"$CLICKHOUSE_PIDFILE\" --config-file=\"$CLICKHOUSE_CONFIG\" $(specific_log_file_for_each_process $i)"
				EXIT_STATUS=$?
				if [ $EXIT_STATUS -ne 0 ]; then
					break
				fi
			fi
	fi

	if [ $EXIT_STATUS -eq 0 ]; then
		echo "DONE"
	else
		echo "FAILED"
	fi

	return $EXIT_STATUS
}

stop()
{
	local EXIT_STATUS
	EXIT_STATUS=0

	if [ -f $CLICKHOUSE_PIDFILE ]; then

		echo -n "Stop $PROGRAM service: "

		kill -TERM `cat "$CLICKHOUSE_PIDFILE"`

		wait4done

		echo "DONE"
	fi
	return $EXIT_STATUS
}

restart()
{
	stop
	start
}

forcestop()
{
	local EXIT_STATUS
	EXIT_STATUS=0

	echo -n "Stop $PROGRAM service: "

	kill -9 `cat "$CLICKHOUSE_PIDFILE"`

	wait4done

	echo "DONE"
	return $EXIT_STATUS
}

forcerestart()
{
	forcestop
	start
}

enable_cron()
{
	[ ! -z $CLICKHOUSE_CRONFILE ] && sed -i 's/^#*//' "$CLICKHOUSE_CRONFILE"
}

disable_cron()
{
	[ ! -z $CLICKHOUSE_CRONFILE ] && sed -i 's/^#*/#/' "$CLICKHOUSE_CRONFILE"
}

is_cron_disabled()
{
	[ -z $CLICKHOUSE_CRONFILE ] && return 0
	[[ `grep -E "^#.*" $CLICKHOUSE_CRONFILE` == `cat $CLICKHOUSE_CRONFILE` ]];
}

main()
{
	# See how we were called.
	EXIT_STATUS=0
	case "$1" in
	start)
		start && enable_cron
		;;
	stop)
		disable_cron && stop
		;;
	restart)
		restart && enable_cron
		;;
	forcestop)
		disable_cron && forcestop
		;;
	forcerestart)
		forcerestart && enable_cron
		;;
	reload)
		restart
		;;
	condstart)
		all_runs || start
		;;
	condstop)
		any_runs && stop
		;;
	condrestart)
		any_runs && restart
		;;
	condreload)
		any_runs && restart
		;;
	initdb)
		initdb
		;;
	*)
		# Print current script name
		echo "Usage: ${0##*/} $SUPPORTED_COMMANDS"
		exit 2
		;;
	esac

	exit $EXIT_STATUS
}

status()
{
	if [ $(running_processes) -eq 1 ]; then
		echo "$PROGRAM service is running"
	else
		if is_cron_disabled; then
			echo "$PROGRAM service is stopped";
		else
			echo "$PROGRAM: process unexpectedly terminated"
		fi
	fi
}

# Running commands without need of locking
case "$1" in
status)
	status
	exit 0
	;;
esac

(
	if flock -n 9; then
		main "$@"
	else
		echo "Init script is already running" && exit 1
	fi
) 9> $LOCKFILE