Carrierwave ImageUploader that uploads images to Rackspace Files

ImageUploader.rb

# encoding: utf-8

class ImageUploader < CarrierWave::Uploader::Base

  # Include RMagick or MiniMagick support:
  # include CarrierWave::RMagick
  include CarrierWave::MiniMagick
  include CarrierWaveDirect::Uploader
  # process :set_content_type

  # 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 :big do
    process :resize_to_fill => [960, 360]
  end

  # version :medium, :from_version => :big do
  #   process :resize_to_fit => [860, 268]
  # end

  version :thumb, :from_version => :big do
    process :resize_to_fit => [320, 120]
  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

With this ImageUploader in place, I could only upload files to Rackspace by editing a model of the Image class. If you create a new Image WITH an image in place, you'll see an error.

Just delete line 9 of this file. That will fix you problem. Files won't be directly uploade to the Rackspace cloud, but they will go via your server

For more information: http://stackoverflow.com/questions/11187665/rails-uploading-images-to-amazon-s3-via-carrierwave-only-works-on-edit