Carrierwave+fog+s3 not working with Cloud Front URLs - ruby-on-rails

Question

I'm having this problem with carrierwave+fog+s3 with Amazon cloud front. With the following setup I can upload files to s3 but after uploaded, the S3 Objects URLs I get from my rails app doesn't have the assets_host based URLs i.e I'm expeting the URLs to be looks like this format https://mycloudfrontname.cloudfront.net/uploads/myfile.mp3
But they all appear in this format https://mybucketname.s3.amazonaws.com/uploads/myfile.mp3
What might be wrong here?
CarrierWave.configure do |config|
config.fog_credentials = {
:provider => 'AWS',
:aws_access_key_id => 'XXXX',
:aws_secret_access_key => 'XXXX',
:region => 'us-east-1'
}
config.fog_directory = 'mybucketname'
config.asset_host = 'https://mycloudfrontname.cloudfront.net'
config.fog_public = false
config.fog_attributes = {'Cache-Control' => 'max-age=315576000'}
end
UPDATE:
I found this code bit from Carrierwave's /lib/carrierwave/storage/fog.rb - So if we set the asset_host as on above code snippet this must work right? or is there any other configuration I must do as well?
def public_url
if host = #uploader.asset_host
if host.respond_to? :call
"#{host.call(self)}/#{path}"
else
"#{host}/#{path}"
end
else
# AWS/Google optimized for speed over correctness
case #uploader.fog_credentials[:provider]
when 'AWS'
# if directory is a valid subdomain, use that style for access
if #uploader.fog_directory.to_s =~ /^(?:[a-z]|\d(?!\d{0,2}(?:\d{1,3}){3}$))(?:[a-z0-9\.]|(?![\-])|\-(?![\.])){1,61}[a-z0-9]$/
"https://#{#uploader.fog_directory}.s3.amazonaws.com/#{path}"
else
# directory is not a valid subdomain, so use path style for access
"https://s3.amazonaws.com/#{#uploader.fog_directory}/#{path}"
end
when 'Google'
"https://commondatastorage.googleapis.com/#{#uploader.fog_directory}/#{path}"
else
# avoid a get by just using local reference
directory.files.new(:key => path).public_url
end
end
end

Answer 1

Change config.fog_public to true and add config.asset_host = 'YOUR_CND_ADDRESS'. The asset_host doesn't work when fog_public is false

Answer 2

In your environment file you need to set the asset host. Just add the line below to your config/environments/production.rb file, and you should be okay. Also may want to make sure you're using the latest version of carrierwave and fog gems.
-- config/environments/production.rb
Myapp::Application.configure do
# Use Content Delivery Network for assets
config.action_controller.asset_host = 'https://mycloudfrontname.cloudfront.net'
end

Answer 3

Don't use asset_host. The asset_host setting is for files served by the rails asset helpers. CarrierWave files are handled in a different manner. The config you are looking for is config.fog_host
config.fog_host = 'https://mycloudfrontname.cloudfront.net'