Init script for multiple unicorns using rbenv

etc-init.d-unicorn

#! /bin/sh
### BEGIN INIT INFO
# Provides:          unicorn
# Required-Start:    $all
# Required-Stop:     $network $local_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: starts the unicorn web server
# Description:       starts unicorn
### END INIT INFO

# init.d script for single or multiple unicorn installations using rbenv. Expects at least one .conf 
# file in /etc/unicorn
#
# Modified by mamhoff@gmail.com
# based on https://gist.github.com/nebiros/2776085 by https://gist.github.com/nebiros and
# based on http://gist.github.com/308216 by http://github.com/mguterl
#
## A sample /etc/unicorn/my_app.conf
## 
## ENV=production
## APP_ROOT=/var/apps/www/my_app/current
#
# This configures a unicorn master for your app at /var/apps/www/my_app/current running in
# production mode. It will read config/unicorn.rb for further set up. 
# 
# This file will run the unicorn server as the user who owns the directory $APP_ROOT. Please
# make sure rbenv is loaded in that users ~/.profile ! 
#
# You should ensure different ports or sockets are set in each config/unicorn.rb if
# you are running more than one master concurrently.
#
# If you call this script without any config parameters, it will attempt to run the
# init command for all your unicorn configurations listed in /etc/unicorn/*.conf
#
# /etc/init.d/unicorn start # starts all unicorns
#
# If you specify a particular config, it will only operate on that one
#
# /etc/init.d/unicorn start /etc/unicorn/my_app.conf

set -e
setup () {
  APP_USER=$(ls -ld $APP_ROOT | awk '{print $3}')
  RBENV_ROOT="/home/$APP_USER/.rbenv"
  RBENV_RUBY_VERSION=$(cat $APP_ROOT/.ruby-version)
  PATH="$RBENV_ROOT/bin:$RBENV_ROOT/shims:$PATH"
  SET_PATH="cd $APP_ROOT; rbenv rehash; rbenv local $RBENV_RUBY_VERSION"
  DAEMON_OPTS="-c $APP_ROOT/config/unicorn.rb -E $ENV -D"
  DAEMON="bundle exec unicorn"
  CMD="$SET_PATH; $DAEMON $DAEMON_OPTS"
  PID="$APP_ROOT/tmp/pids/unicorn.pid"
  OLD_PID="$PID.oldbin"
  cd $APP_ROOT || exit 1
}

sig () {
  test -s "$PID" && kill -$1 `cat "$PID"`
}

oldsig () {
  test -s "$OLD_PID" && kill -$1 `cat "$OLD_PID"`
}

cmd () {

  case $1 in
    start)
      sig 0 && echo >&2 "Already running" && exit 0
      echo "Starting"
      su -c "$CMD" - $APP_USER
      ;;  
    stop)
      sig QUIT && echo "Stopping" && exit 0
      echo >&2 "Not running"
      ;;  
    force-stop)
      sig TERM && echo "Forcing a stop" && exit 0
      echo >&2 "Not running"
      ;;  
    restart|reload)
      sig USR2 && sleep 5 && oldsig QUIT && echo "Killing old master" `cat $OLD_PID` && exit 0
      echo >&2 "Couldn't reload, starting '$CMD' instead"
      su -c "$CMD" - $APP_USER
      ;;  
    upgrade)
      sig USR2 && echo Upgraded && exit 0
      echo >&2 "Couldn't upgrade, starting '$CMD' instead"
      su -c "$CMD" - $APP_USER
      ;;  
    rotate)
            sig USR1 && echo rotated logs OK && exit 0
            echo >&2 "Couldn't rotate logs" && exit 1
            ;;  
    *)  
      echo >&2 "Usage: $0 <start|stop|restart|upgrade|rotate|force-stop>"
      exit 1
      ;;  
    esac
}


start_stop () {
  
  # either run the start/stop/reload/etc command for every config under /etc/unicorn
  # or just do it for a specific one

  # $1 contains the start/stop/etc command
  # $2 if it exists, should be the specific config we want to act on
  if [ $2 ]; then
    . $2
    setup
    cmd $1
  else
    for CONFIG in /etc/unicorn/*.conf; do
      # import the variables
      . $CONFIG
      setup

      # run the start/stop/etc command
      cmd $1
    done
   fi
}

ARGS="$1 $2"
start_stop $ARGS