class Article < ActiveRecord::Base
    mount_uploader :poster, PosterUploader
  end

  Article.features.has_carrierwave_uploaders?                   # => true
  Article.attribute_features[:poster].has_carrierwave_uploader? # => true
  Article.attribute_features[:poster].carrierwave.mounted_on    # => :poster

Gemfile

gem 'essay-carrierwave', github: 'yivo/essay-carrierwave'