cron script to shutdown boot2docker

dockerstop.zsh

#!/bin/zsh
# set cron to run this every couple of minutes and it will shutdown boot2docker 
# when its been running with no processes for maxminutes
maxminutes=10

local bdout
local dpqout
bdout=$(boot2docker status) 2>/dev/null
if [[ $bdout = "running" ]]; then
  echo "boot2docker running"
  dpqout=$(docker ps -q) 2>/dev/null

  if [[ $dpqout = "" ]]; then
    echo "but no processes running"
    if [[ -f ~/.bddowntime ]]; then
      echo "downtime file exists"
      while read firsttime; do
        local nowtime
        nowtime=$(date +"%s")
        diff=$(($nowtime-$firsttime))
        (( maxseconds=$maxminutes*60 ))
        echo $diff
        echo $maxseconds
        if [[ $diff -gt $maxseconds ]]; then
          echo "Been down a while. Shutting down boot2docker"
          echo $diff
          boot2docker down
        fi
      done < ~/.bddowntime
    else
      echo "it doesnt exist so creating downtime file"
      echo $(date +"%s") > ~/.bddowntime
    fi
  else
    echo "and docker ps has processes"
  fi
else
  echo "not running"
  if [[ -f ~/.bddowntime ]]; then
    echo "and the file was there"
    rm ~/.bddowntime
  fi
fi