#!/bin/sh
#
# gangliarc Ganglia monitoring for ARC services
#
# chkconfig: - 75 25
# description: Ganglia monitoring for ARC services
#
# config: /etc/sysconfig/nordugrid
# config: /etc/arc.conf

### BEGIN INIT INFO
# Provides:          gangliarc
# Required-Start:    $local_fs $remote_fs
# Required-Stop:     $local_fs $remote_fs
# Default-Start:
# Default-Stop:
# Short-Description: Ganglia monitoring for ARC services
# Description:       gangliarc adds ARC service-related information to Ganglia
### END INIT INFO

# source function library
if [ -f /etc/init.d/functions ]; then
    . /etc/init.d/functions
    log_success_msg() {
        echo -n "$@"
        success "$@"
        echo
    }
    log_warning_msg() {
        echo -n "$@"
        warning "$@"
        echo
    }
    log_failure_msg() {
        echo -n "$@"
        failure "$@"
        echo
    }
elif [ -f /lib/lsb/init-functions ]; then
    . /lib/lsb/init-functions
else
    echo "Error: Cannot source neither init.d nor lsb functions"
    exit 1
fi

prog=gangliarc
RUN=yes

# sysconfig files
if [ -r /etc/sysconfig/nordugrid ]; then
    . /etc/sysconfig/nordugrid
elif [ -r /etc/default/nordugrid ]; then
    . /etc/default/nordugrid
fi
if [ -r /etc/sysconfig/${prog} ]; then
    . /etc/sysconfig/${prog}
elif [ -r /etc/default/${prog} ]; then
    . /etc/default/${prog}
fi

readconfigvar() {
    fname=$1
    if [ ! -r "$fname" ]; then
      return
    fi
    bname="[$2]"
    vname=$3
    value=
    cat "$fname" | grep -e '^\[' -e "^${vname}=" | {
        while true; do
            read line
            if [ ! $? = 0 ] ; then
                return
            fi
            if [ "$line" = "$bname" ] ; then
                while true ; do
                    read line
                    if [ ! $? = 0 ] ; then
                        return
                    fi
                    lstart=`echo "$line" | head -c 1`
                    if [ "$lstart" = '[' ] ; then
                        return
                    fi
                    vlname=`echo "$line" | sed 's/=.*//;t;s/.*//'`
                    if [ "$vlname" = "$vname" ] ; then
                        val=`echo "$line" | sed 's/[^=]*=//'`
                        eval "echo $val"
                        return
                    fi
                done
            fi
        done
    }
}

# ARC_CONFIG
if [ "x$ARC_CONFIG" = "x" ]; then
    if [ -r $ARC_LOCATION/etc/arc.conf ]; then
        ARC_CONFIG=$ARC_LOCATION/etc/arc.conf
    elif [ -r /etc/arc.conf ]; then
        ARC_CONFIG=/etc/arc.conf
    fi
fi

if [ ! -r "$ARC_CONFIG" ]; then
    log_error_msg "ARC configuration not found (usually /etc/arc.conf)"
    exit 1
fi

CMD=`readconfigvar "$ARC_CONFIG" gangliarc python_bin_path`
if [ "x$CMD" = "x" ]; then
    CMD=/usr/bin/python
fi

if [ ! -x "$CMD" ]; then
    log_failure_msg "Cannot find python executable"
    exit 1
fi


PID_FILE=`readconfigvar "$ARC_CONFIG" gangliarc pidfile`
LOG_FILE=`readconfigvar "$ARC_CONFIG" gangliarc logfile`

if [ `id -u` = 0 ] ; then
    # Debian does not have /var/lock/subsys
    if [ -d /var/lock/subsys ]; then
        LOCKFILE=/var/lock/subsys/$prog
    else
        LOCKFILE=/var/lock/$prog
    fi
    if [ "x$PID_FILE" = "x" ]; then
        PID_FILE=/var/run/$prog.pid
    fi
    if [ "x$LOG_FILE" = "x" ]; then
        LOG_FILE=/var/log/arc/$prog.log
    fi
else
    LOCKFILE=$HOME/$prog.lock
    if [ "x$PID_FILE" = "x" ]; then
        PID_FILE=$HOME/$prog.pid
    fi
    if [ "x$LOG_FILE" = "x" ]; then
        LOG_FILE=$HOME/$prog.log
    fi
fi

CMD="$CMD -c 'import gangliarc; gangliarc.run(\"$ARC_CONFIG\", \"$PID_FILE\", \"$LOG_FILE\")'"

start() {

    if [ "$RUN" != "yes" ] ; then
        echo "gangliarc disabled, please adjust the configuration to your needs "
        echo "and then set RUN to 'yes' in /etc/default/gangliarc to enable it."
        return 0
    fi

    echo -n "Starting $prog: "

    # Check if we are already running
    if [ -f $PID_FILE ]; then
        read pid < $PID_FILE
        if [ "x$pid" != "x" ]; then
            ps -p "$pid" -o comm 2>/dev/null | grep "^python$" 1>/dev/null 2>/dev/null
            if [ $? -eq 0 ] ; then
                log_success_msg "already running (pid $pid)"
                return 0
            fi
        fi
        rm -f "$PID_FILE" "$LOCKFILE"
    fi

    eval "$CMD"
    RETVAL=$?

    if [ $RETVAL -eq 0 ]; then
        touch $LOCKFILE
        log_success_msg
    else
        log_failure_msg
    fi
    return $RETVAL
}

stop() {
    echo -n "Stopping $prog: "

    if [ -f "$PID_FILE" ]; then
        read pid < "$PID_FILE"
        if [ ! -z "$pid" ] ; then
            kill "$pid"
            RETVAL=$?
            if [ $RETVAL -eq 0 ]; then
                log_success_msg
            else
                log_failure_msg
            fi

            sleep 1
            kill -9 "$pid" 1>/dev/null 2>&1
            rm -f "$PID_FILE" "$LOCKFILE"
        else
            RETVAL=1
            log_failure_msg "$prog shutdown - pidfile is empty"
        fi
    else
        RETVAL=0
        log_success_msg "$prog shutdown - already stopped"
    fi
    return $RETVAL
}

status() {
    if [ -f "$PID_FILE" ]; then
        read pid < "$PID_FILE"
        if [ "$pid" != "" ]; then
            if ps -p "$pid" > /dev/null; then
                echo "$1 (pid $pid) is running..."
                return 0
            fi
            echo "$1 stopped but pid file exists"
            return 1
        fi
    fi
    if [ -f $LOCKFILE ]; then
        echo "$1 stopped but lockfile exists"
        return 2
    fi
    echo "$1 is stopped"
    return 3
}

restart() {
    stop
    start
}

case "$1" in
    start)
        start
        ;;
    stop)
        stop
        ;;
    status)
        status $prog
        ;;
    restart | force-reload)
        restart
        ;;
    reload)
        ;;
    condrestart | try-restart)
        [ -f $LOCKFILE ] && restart || :
        ;;
    *)
        echo "Usage: $0 {start|stop|status|restart|force-reload|reload|condrestart|try-restart}"
        exit 1
        ;;
esac

exit $?
