Shell script to control the start, stop and restart of a node application.

appctl.sh

#!/bin/sh

## Script to control the applicaion start and stop
## Note, if the application was started separate to this script,
## then there is a risk that it will be started twice.

## Also note if you plan to use this with systemd, then you need to ensure
## the 'Service' section looks as follows:

## [Service]
## User=theuser
## Group=thegroup
## Type=oneshot
## Environment=ENV=production
## Environment=NODE_ENV=production
## WorkingDirectory=/home/theuser/myapp
## ExecStart=/home/theuser/myapp/scripts/appctl.sh start
## ExecStop=/home/theuser/myapp/appctl.sh stop
## RemainAfterExit=true

scripts_dir=`dirname $0`
cd "${scripts_dir}/"..

appname="my-app-name"
pidfile="${PWD}/${appname}.pid"
logfile="${PWD}/${appname}.log"

stop() {
    printf "Stopping ${appname} ... "
    if [ -f "${pidfile}" ]; then
       kill `cat "${pidfile}"`
       rm "${pidfile}"
       printf "done\n"
    else
       printf "not running\n"
    fi
}

start() {
   echo "Starting ${appname}"
   if [ -f "${pidfile}" ]; then
       if kill -0 $(cat "${pidfile}") 2>/dev/null; then
           echo "Error: application is already running"
           exit 1
       fi
   fi
   echo "pwd: $PWD"
   node lib --label "${appname}" >> "${logfile}" &
   echo $! > "${pidfile}"
}

restart () {
    echo "Restarting ${appname}:"
    stop
    start
}

status() {
   printf "Status of ${appname} .... "
   if [ -f "${pidfile}" ]; then
       if kill -0 $(cat "${pidfile}") 2>/dev/null; then
          echo "running ($(cat "${pidfile}"))"
          exit 0
       fi          
    fi
    echo "not running"
       
}

action=$1

if [ -z ${action} ]; then
    echo "required one of: start | stop | restart"
elif [ ${action} = 'restart' ]; then
    restart
elif [ ${action} = 'start' ]; then
    start
elif [ ${action} = 'stop' ]; then
    stop
elif [ ${action} = 'status' ]; then
    status    
else
    echo "unknown action, speficify one of: start, stop, restart or status"
fi