docker upstart redis startup script

redis.conf

description "Redis container"
author "Ivan Prisyazhnyy"

start on filesystem and started docker
stop on runlevel [!2345] or stopping docker

# Docker has a timeout of 10 seconds so as long as this
# is longer so we don't kill the wait process
kill timeout 20
 
# We don't want to TERM the `docker wait` process so we fake the signal 
# we send to it. The pre-stop script issues the `docker stop` command
# which causes the `docker wait` process to exit
kill signal CONT
 
# Due to a bug in upstart we need to set the modes we consider
# successful exists https://bugs.launchpad.net/upstart/+bug/568288
normal exit 0 CONT

respawn
respawn limit 3 5

limit nofile 65535 65535

# instance $PORT

script
  NAME="redis"
  PORT=6379
  
  ID=`docker ps -a | grep ${NAME}-${PORT} | cut -f 1 -d ' '`
 
  START=1
  if [ ! -z "${ID}" ]; then
    if docker ps | grep -q "${ID}"; then
      START=0
    else
      NID=$(docker start ${ID})
      [ "${NID}" = "${ID}" ] && START=0
    fi
  fi
  
  if [ $START -ne 0 ]; then
    ID=$(docker run -d --name ${NAME}-${PORT} \
        -h `hostname` \
        -p 127.0.0.1::6379 \
        -v /var/liv/redis/6379:/data \
        redis \
        redis-server \
        --appendonly yes)
  fi
 
  exec docker wait ${ID}
end script

pre-stop script
  NAME="redis"
  PORT=6379

  ID=`docker ps -a | grep ${NAME}-${PORT} | cut -f 1 -d ' '`

  if [ ! -z "${ID}" ]; then
     docker stop "${ID}"
  fi
end script