RackHD/on-syslog

#!/bin/sh

### BEGIN INIT INFO
# Provides:          on-syslog
# Required-Start:    $syslog $network mongodb rabbitmq-server
# Required-Stop:     $syslog $network
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: on-syslog
# Description:       RackHD on-syslog service
### END INIT INFO

NAME="on-syslog"
USER="root"
APP_DIR="/var/renasar/$NAME"
NODE_APP="index.js"
PID_DIR="/var/run"
PID_FILE="$PID_DIR/$NAME.pid"
LOG_DIR="/var/log/rackhd"
LOG_FILE="$LOG_DIR/$NAME.log"
NODE_EXEC=$(which node)

USAGE="Usage: $0 {start|stop|restart|status}"
RESTART=false

# Time to wait for the server to die, in seconds
DIETIME=1
STARTTIME=1
if [ ! -f "/etc/default/$NAME" ]
then
    echo "Service disabled due to absence of /etc/default/$NAME" 1>&2
    exit 1
else
     . "/etc/default/$NAME"
fi


pid_file_exists() {
    [ -f "$PID_FILE" ]
}

get_pid() {
    echo "$(cat "$PID_FILE")"
}

is_running() {
    PID=$(get_pid)
    ! [ -z "$(ps aux | awk '{print $2}' | grep "^$PID$")" ]
}

start_it() {
    if [ ! -d $PID_DIR ]; then mkdir -p "$PID_DIR"; fi
    if [ ! -d $LOG_DIR ]; then mkdir -p "$LOG_DIR"; fi

    echo "Starting $NAME ..."
    /sbin/start-stop-daemon --background --start --quiet\
        --make-pidfile --pidfile $PID_FILE \
        -d $APP_DIR \
        --startas /bin/bash -- -c "exec $NODE_EXEC $APP_DIR/$NODE_APP >> $LOG_FILE 2>&1"
}

stop_process() {
    echo "Killing process $PID"
    /sbin/start-stop-daemon -K --quiet --pidfile $PID_FILE --retry 300
    return $?
}

remove_pid_file() {
    echo "Removing pid file"
    rm -f "$PID_FILE"
}

start_app() {
    if pid_file_exists
    then
        if is_running
        then
            PID=$(get_pid)
            echo "$NAME already running with pid $PID"
            exit 0
        else
            echo "$NAME stopped, but pid file exists"
            remove_pid_file
        fi
    fi

    start_it && sleep $STARTTIME
    if is_running
    then
        echo "$NAME started with pid $(get_pid)"
    else
        echo "Failed to start $NAME"
        exit 1
    fi
}

stop_app() {
    if pid_file_exists
    then
        if is_running
        then
            echo "Stopping $NAME ..."
            if stop_process
            then
                remove_pid_file
                echo "$NAME stopped"
            else
                echo "Failed to stop $NAME"
                exit 1
            fi
        else
            echo "$NAME already stopped, but pid file exists"
            remove_pid_file
            echo "$NAME stopped"
        fi
    else
        echo "$NAME already stopped, pid file does not exist"
    fi
}

status_app() {
    if pid_file_exists
    then
        if is_running
        then
            PID=$(get_pid)
            echo "$NAME running with pid $PID"
            exit 0
        else
            echo "$NAME stopped, but pid file exists"
            exit 1
        fi
    else
        echo "$NAME stopped"
        exit 2
    fi
}

case "$1" in
    start)
        start_app
    ;;

    stop)
        stop_app
    ;;

    restart)
        stop_app && sleep $DIETIME
        start_app
    ;;

    status)
        status_app
    ;;

    *)
        echo $USAGE
        exit 1
    ;;
esac