discourse/config/unicorn_launcher

#!/bin/bash

# This is a helper script you can use to supervise unicorn, it allows you to perform a live restart
# by sending it a USR2 signal

LOCAL_WEB="http://127.0.0.1:3000/"

function on_exit()
{
  kill $UNICORN_PID
  echo "exiting"
}

function on_reload()
{
  echo "Reloading unicorn"
  kill -s USR2 $UNICORN_PID
  sleep 10
  curl $LOCAL_WEB &> /dev/null
  NEW_UNICORN_PID=`ps -f --ppid $UNICORN_PID | grep unicorn | grep -v worker | awk '{ print $2 }'`
  kill $UNICORN_PID
  echo "Old pid is: $UNICORN_PID New pid is: $NEW_UNICORN_PID"
  UNICORN_PID=$NEW_UNICORN_PID
}

export UNICORN_SUPERVISOR_PID=$$

trap on_exit EXIT
trap on_reload USR2

unicorn $@ &
UNICORN_PID=$!

echo "supervisor pid: $UNICORN_SUPERVISOR_PID unicorn pid: $UNICORN_PID"

while [ -e /proc/$UNICORN_PID ]
do
  sleep 0.1
done