Add Cloudfront support

config/initializers/paperclip.rb

@@ -7,6 +7,11 @@ if ENV['S3_ENABLED'] == 'true'
   Paperclip::Attachment.default_options[:s3_host_name] = "s3-#{ENV.fetch('S3_REGION')}.amazonaws.com"
   Paperclip::Attachment.default_options[:path]         = '/:class/:attachment/:id_partition/:style/:filename'
 
+  if ENV['S3_CLOUDFRONT_HOST'] == ''
+    Paperclip::Attachment.default_options[:url]           = ':s3_alias_url'
+    Paperclip::Attachment.default_options[:s3_host_alias] = ENV['S3_CLOUDFRONT_HOST']
+  end
+
   Paperclip::Attachment.default_options[:s3_credentials] = {
     bucket: ENV.fetch('S3_BUCKET'),
     access_key_id: ENV.fetch('AWS_ACCESS_KEY_ID'),