Using CarrierWave and Fog With Private Rackspace Cloud Files.

During a recent project, I used Rackspace Cloud Files (an S3 equivalent run by Rackspace) to store mp3 files. Since the files I was working with were attached to ActiveRecord models, I immediately turned to CarrierWave. CarrierWave makes this really easy, simply configure appropriately:

CarrierWave.configure do |config|
  config.fog_credentials = {
    :provider               => 'Rackspace',
    :rackspace_username     => ENV['RACKSPACE_USERNAME'],
    :rackspace_api_key      => ENV['RACKSPACE_API_KEY'],
    :rackspace_servicenet   => Rails.env.production?,
    :rackspace_temp_url_key => ENV['RACKSPACE_URL_KEY']
  config.fog_directory = 'mp3s'
  config.fog_public = false

Add an Uploader class to your model and you are nearly all the way there:

class RecordingUploader < CarrierWave::Uploader::Base
  storage :fog

class Recording < ActiveRecord::Base
  mount_uploader :file, RecordingUploader

But, I hit a snag. Not wanting the files I was uploading to be publicly available, I had configured fog_public = false in the CarrierWave configuration. But when I tried accessing the files from my AR model, I kept getting errors. At time of writing, the latest version of CarrierWave (0.7.1) did not support private Cloud Files. Fortunately for me, CarrierWave master did. Assuming that was all I needed, I was hopeful that my problem was fully solved but I was still having issues.

What I had missed was the rackspace_temp_url_key. This is something you need to established before use. I couldn’t find a way to do this on Rackspace’s website, but fortunately, Fog exposes an easy way to set this via API. I stuck a little bin script in my scripts directory and ran it to set a key:

#!/usr/bin/env ruby

require 'rubygems'
require 'bundler/setup'
require 'fog'

                           :rackspace_api_key  => ENV['RACKSPACE_API_KEY'],
                           :provider           => 'Rackspace')

Once the rackspace_temp_url_key was properly setup, I was all set. Private Cloud Files accessible using CarrierWave.