#!/bin/sh

# Short-Description:  Create lightweight, portable, self-sufficient containers.
# Description:
#  Docker is an open-source project to easily create lightweight, portable,
#  self-sufficient containers from any application. The same container that a
#  developer builds and tests on a laptop can run at scale, in production, on
#  VMs, bare metal, OpenStack clusters, public clouds and more.


PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin

BASE=docker

UNSHARE=/usr/bin/unshare
DOCKER=/usr/bin/$BASE
DOCKER_PIDFILE=/var/run/$BASE.pid
DOCKER_LOG=/var/log/docker.log
DOCKER_OPTS=

if [ -f /etc/default/$BASE ]; then
	. /etc/default/$BASE
fi

# Check docker is present
if [ ! -x $DOCKER ]; then
	echo "$DOCKER not present or not executable"
	exit 1
fi

docker_start() {
  echo "starting $BASE ..."
  if [ -x ${DOCKER} ]; then
    # If there is an old PID file (no docker running), clean it up:
    if [ -r ${DOCKER_PIDFILE} ]; then
      if ! ps axc | grep docker 1> /dev/null 2> /dev/null ; then
        echo "Cleaning up old ${DOCKER_PIDFILE}."
        rm -f ${DOCKER_PIDFILE}
      fi
    fi
    nohup "${UNSHARE}" -m -- ${DOCKER} -d -p ${DOCKER_PIDFILE} ${DOCKER_OPTS} >> ${DOCKER_LOG} 2>&1 &
  fi
}

# Stop docker:
docker_stop() {
  echo "stopping $BASE ..."
  # If there is no PID file, ignore this request...
  if [ -r ${DOCKER_PIDFILE} ]; then
    kill $(cat ${DOCKER_PIDFILE})
  fi
}

# Restart docker:
docker_restart() {
	docker_stop
	docker_start
}

case "$1" in
'start')
  docker_start
  ;;
'stop')
  docker_stop
  ;;
'restart')
  docker_restart
  ;;
'status')
  if [ -f ${DOCKER_PIDFILE} ] && ps -o cmd $(cat ${DOCKER_PIDFILE}) | grep -q $BASE ; then
	  echo "status of $BASE: running"
  else
	  echo "status of $BASE: stopped"
  fi
  ;;
*)
  echo "usage $0 start|stop|restart|status"
esac

exit 0