Rails应用程序可以在本地使用载波在S3上正常运行，在Heroku上崩溃，并显示错误消息“无法自动加载常量”

Question

我正在使用carrierwave gem将用户上传到S3的用户存储在我安装到我的在线商店应用程序的Rails引擎中。 本地一切正常，我检查了S3以确保文件已上传。

我将应用程序部署到了Heroku，并且部署成功。 我还在Heroku上很好地设置了我的AWS访问密钥，秘密密钥和存储桶变量。 但是，当我尝试打开应用程序页面时，出现“应用程序错误”页面。 当我查看Heroku日志时，发现以下行：

/app/vendor/bundle/ruby/2.0.0/gems/activesupport-4.0.8/lib/active_support/dependencies.rb:464:in `load_missing_constant': Unable to autoload constant Prodeng::ProductImageUploader, expected /app/prodeng/app/uploaders/prodeng/product_image_uploader.rb to define it (LoadError)

Prodeng是我在应用程序中安装的Rails引擎的名称空间。 我真的不确定为什么会这样，但这也是我第一次创建Rails引擎并将其安装在应用程序内部。

这是我的Rails引擎中的product_image_uploader.rb（prodeng / app / uploaders / prodeng / product_image_uploader.rb）文件：

class ProductImageUploader < CarrierWave::Uploader::Base

  # Include RMagick or MiniMagick support:
  include CarrierWave::RMagick
  # include CarrierWave::MiniMagick

  # Choose what kind of storage to use for this uploader:
  # storage :file
  storage :fog

  # Override the directory where uploaded files will be stored.
  # This is a sensible default for uploaders that are meant to be mounted:
  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end

  # Provide a default URL as a default if there hasn't been a file uploaded:
  # def default_url
  #   # For Rails 3.1+ asset pipeline compatibility:
  #   # ActionController::Base.helpers.asset_path("fallback/" + [version_name, "default.png"].compact.join('_'))
  #
  #   "/images/fallback/" + [version_name, "default.png"].compact.join('_')
  # end

  # Process files as they are uploaded:
  # process :scale => [200, 300]
  #
  # def scale(width, height)
  #   # do something
  # end

  # Create different versions of your uploaded files:
  version :thumb do
    process :resize_to_fit => [200, 150]
  end

  # Add a white list of extensions which are allowed to be uploaded.
  # For images you might use something like this:
  # def extension_white_list
  #   %w(jpg jpeg gif png)
  # end

  # Override the filename of the uploaded files:
  # Avoid using model.id or version_name here, see uploader/store.rb for details.
  # def filename
  #   "something.jpg" if original_filename
  # end

end

这是我的Rails引擎中的我的carrierwave.rb文件（/prodeng/app/config/initializers/carrierwave.rb）

CarrierWave.configure do |config|
  config.fog_credentials = {
    :provider               => 'AWS',                        
    :aws_access_key_id      => ENV["AWS_ACCESS_KEY"],                       
    :aws_secret_access_key  => ENV["AWS_SECRET_KEY"]                        
  }
  config.fog_directory  = ENV["AWS_BUCKET"]                     
end

这是我的prodeng.gemspec文件

$:.push File.expand_path("../lib", __FILE__)

# Maintain your gem's version:
require "prodeng/version"

# Describe your gem and declare its dependencies:
Gem::Specification.new do |s|
  s.name        = "prodeng"
  s.version     = Prodeng::VERSION
  s.authors     = ["TODO: Your name"]
  s.email       = ["TODO: Your email"]
  s.homepage    = "TODO"
  s.summary     = "TODO: Summary of Prodeng."
  s.description = "TODO: Description of Prodeng."

  s.files = Dir["{app,config,db,lib}/**/*", "MIT-LICENSE", "Rakefile", "README.rdoc"]
  s.test_files = Dir["test/**/*"]

  s.add_dependency "rails", "~> 4.0.8"

  s.add_dependency "carrierwave"
  s.add_dependency "rmagick"

  s.add_development_dependency "sqlite3"
end

如果遗漏了解决此问题所需的任何内容，我深表歉意。 任何帮助或指出正确的方向将不胜感激。 谢谢！

编辑：我忘了包括我的应用程序的Gemfile

source 'https://rubygems.org'
ruby '2.0.0'

gem 'rails', '4.0.8'
gem 'bootstrap-sass', '~> 3.2.0'
gem 'sprockets', '2.11.0'
gem 'bcrypt-ruby', '3.1.2'
gem 'prodeng', :path => './prodeng'
gem 'figaro'
gem 'fog'

group :development, :test do
  gem 'sqlite3', '1.3.8'
  gem 'rspec-rails', '2.13.1'
end

group :test do
  gem 'selenium-webdriver', '2.35.1'
  gem 'capybara', '2.1.0'
  gem 'factory_girl_rails', '4.2.0'
end

gem 'sass-rails', '4.0.3'
gem 'uglifier', '2.1.1'
gem 'coffee-rails', '4.0.1'
gem 'jquery-rails', '3.0.4'
gem 'turbolinks', '1.1.1'
gem 'jbuilder', '1.0.2'

group :doc do
  gem 'sdoc', '0.3.20', require: false
end

group :production do
  gem 'pg', '0.15.1'
  gem 'rails_12factor', '0.0.2'
end

Answer 1

正如Swards在评论中指出的那样，在创建ProductImageUploader类时，我省略了引擎的名称空间。 该类应该这样写：

class Prodeng::ProductImageUploader < CarrierWave::Uploader::Base