#!/bin/bash
#
# tarbitratord      This shell script takes care of starting and stopping tarbitrator.
#
# chkconfig: 2345 99 01
# description: tarbitrator is a arbitrator used in TDengine cluster.
#
#
### BEGIN INIT INFO
# Provides: taoscluster
# Required-Start: $network $local_fs $remote_fs
# Required-Stop: $network $local_fs $remote_fs
# Short-Description: start and stop tarbitrator
# Description: tarbitrator is a arbitrator used in TDengine cluster.
### END INIT INFO

# Source init functions
. /etc/init.d/functions

# Maximum number of open files
MAX_OPEN_FILES=65535

# Default program options
NAME=tarbitrator
PROG=/usr/local/taos/bin/tarbitrator
USER=root
GROUP=root

# Default directories
LOCK_DIR=/var/lock/subsys
PID_DIR=/var/run/$NAME

# Set file names
LOCK_FILE=$LOCK_DIR/$NAME
PID_FILE=$PID_DIR/$NAME.pid

[ -e $PID_DIR ] || mkdir -p $PID_DIR

PROG_OPTS=""

start() {
    echo -n "Starting ${NAME}: "
    # check identity
    curid="`id -u -n`"
    if [ "$curid" != root ] && [ "$curid" != "$USER" ] ; then
        echo "Must be run as root or $USER, but was run as $curid"
        return 1
    fi
    # Sets the maximum number of open file descriptors allowed.
    ulimit -n $MAX_OPEN_FILES
    curulimit="`ulimit -n`"
    if [ "$curulimit" -lt $MAX_OPEN_FILES ] ; then
        echo "'ulimit -n' must be greater than or equal to $MAX_OPEN_FILES, is $curulimit"
        return 1
    fi

    if [ "`id -u -n`" == root ] ; then
        # Changes the owner of the lock, and the pid files to allow
        # non-root OpenTSDB daemons to run /usr/share/opentsdb/bin/opentsdb_restart.py.
        touch $LOCK_FILE && chown $USER:$GROUP $LOCK_FILE
        touch $PID_FILE && chown $USER:$GROUP $PID_FILE
        daemon --user $USER --pidfile $PID_FILE "$PROG $PROG_OPTS &> /dev/null &"
    else
        # Don't have to change user.
        daemon --pidfile $PID_FILE "$PROG $PROG_OPTS &> /dev/null &"
    fi
    retval=$?
    sleep 2
    echo
    [ $retval -eq 0 ] && (findproc > $PID_FILE && touch $LOCK_FILE)
    return $retval
}

stop() {
    echo -n "Stopping ${NAME}: "
    killproc -p $PID_FILE $NAME
    retval=$?
    echo
    # Non-root users don't have enough permission to remove pid and lock files.
    # So, the opentsdb_restart.py cannot get rid of the files, and the command
    # "service opentsdb status" will complain about the existing pid file.
    # Makes the pid file empty.
    echo > $PID_FILE
    [ $retval -eq 0 ] && (rm -f $PID_FILE && rm -f $LOCK_FILE)
    return $retval
}

restart() {
    stop
    start
}

reload() {
    restart
}

force_reload() {
    restart
}

rh_status() {
    # run checks to determine if the service is running or use generic status
    status -p $PID_FILE -l $LOCK_FILE $NAME
}

rh_status_q() {
    rh_status >/dev/null 2>&1
}

case "$1" in
    start)
        rh_status_q && exit 0
        $1
        ;;
    stop)
        rh_status_q || exit 0
        $1
        ;;
    restart)
        $1
        ;;
    reload)
        rh_status_q || exit 7
        $1
        ;;
    force-reload)
        force_reload
        ;;
    status)
        rh_status
        ;;
    condrestart|try-restart)
        rh_status_q || exit 0
        restart
        ;;
    *)
        echo "Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload}"
        exit 2
esac

exit $?
