check_unicorn.rb

#! /usr/bin/ruby
require "rubygems"
require "net/http"
require "socket"

SOCKET_PATH = '/Users/cat/kkbox/kktix/unicorn.sock'

def unicorn_ready
  return false unless File.exist? SOCKET_PATH
  return true if unicorn_return.to_i == 200
end

def unicorn_return
  sock = Net::BufferedIO.new(UNIXSocket.new(SOCKET_PATH))
  request = Net::HTTP::Get.new("/")
  request.exec(sock, "1.1", "/")

  begin
    response = Net::HTTPResponse.read_new(sock)
  end while response.kind_of?(Net::HTTPContinue)
  response.reading_body(sock, request.response_body_permitted?) { }

  response.code
end

puts "Waiting for unicorn_rails..."
(sleep 1; print ".") until unicorn_ready

`/etc/init.d/nginx start`