Unicorn start/stop/restart script for debian / ubuntu

unicorn.sh

#!/bin/sh
### BEGIN INIT INFO
# Provides:          unicorn
# Required-Start:    $local_fs $remote_fs
# Required-Stop:     $local_fs $remote_fs
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: unicorn initscript
# Description:       Unicorn is an HTTP server for Rack application
### END INIT INFO

# based on http://gist.github.com/308216 by http://github.com/mguterl
#
## A sample /etc/unicorn/my_app.conf
## 
## RAILS_ENV=production
## RAILS_ROOT=/var/apps/www/my_app/current
## PID=$RAILS_ROOT/tmp/unicorn.pid
## START_CMD="bundle exec unicorn"
## USER="www-data"
## PATH=/usr/local/bin:/usr/bin:/bin

set -x

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

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

run_cmd() {
  if [ -z "$SUDO" ]; then
    $CMD
  else
    $SUDO "$CMD"
  fi
}

cmd () {

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

setup () {
  echo -n "$RAILS_ROOT: "
  cd $RAILS_ROOT || exit 1

  if [ -z "$PID" ]; then
    PID=$RAILS_ROOT/tmp/pids/unicorn.pid
  fi

  export PID
  export OLD_PID="$PID.oldbin"
  export RAILS_ROOT

  if [ -z "$START_CMD" ]; then
    START_CMD="bundle exec unicorn_rails"
  fi
  CMD="cd $RAILS_ROOT && $START_CMD -c $UNICORN_CONFIG -E $RAILS_ENV -D"
  export CMD
  #echo $CMD

  SUDO=""
  if [ "$USER" != `whoami` ]; then
    SUDO="sudo -u $USER PATH=$PATH sh -c"
  fi
  export SUDO
}

process_environment () {
  # run a command against an environment:
  #
  # $1 : /etc/unicorn/app.conf
  # $2 : start/stop/etc
  . $1
  export UNICORN_CONFIG="$RAILS_ROOT/config/unicorn.rb"
  setup
  cmd $2
}

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 [ -f "/etc/unicorn/$2.conf" ]; then
    process_environment "/etc/unicorn/$2.conf" "$1"
  else
    for CONFIG in /etc/unicorn/*.conf; do
      process_environment "$CONFIG" "$1"
      unset PID
    done
  fi
}

ARGS="$1 $2"
start_stop $ARGS