Mini Shell

#!/bin/bash
### BEGIN INIT INFO
# Provides:
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: bakmgr
# Description:       IMH Backup Manager
### END INIT INFO

pid_file="/var/run/bakmgr.pid"

get_pid() {
    cat "$pid_file"
}

is_running() {
    [ -f "$pid_file" ] && ps -p "$(get_pid)" > /dev/null 2>&1
}

case "$1" in
    start)
    if is_running; then
        echo "Already started"
    else
        echo "Starting bakmgr"
        cd /opt/bakmgr/dash || exit 1
        /opt/bakmgr/bin/gunicorn -c /opt/bakmgr/dash/dash.conf.py dash_app:app >> /var/log/bakmgr-dash.log 2>&1 &
        echo $! > "$pid_file"
        if ! is_running; then
            echo "Unable to start, See /var/log/bakmgr-dash.log"
            exit 1
        fi
    fi
    ;;
    stop)
    if is_running; then
        echo -n "Stopping bakmgr..."
        kill "$(get_pid)"
        for _ in {1..3}; do
            if ! is_running; then
                break
            fi

            echo -n "."
            sleep 1
        done
        echo

        if is_running; then
            echo "Not stopped; may still be shutting down or shutdown may have failed"
            exit 1
        else
            echo "Stopped"
            if [ -f "$pid_file" ]; then
                rm "$pid_file"
            fi
        fi
    else
        echo "Not running"
    fi
    ;;
    restart)
    $0 stop
    if is_running; then
        echo "Unable to stop, will not attempt to start"
        exit 1
    fi
    $0 start
    ;;
    status)
    if is_running; then
        echo "Running"
    else
        echo "Stopped"
        exit 1
    fi
    ;;
    *)
    echo "Usage: $0 {start|stop|restart|status}"
    exit 1
    ;;
esac

exit 0