Serving files over HTTPS dynamically based on request.ssl? with Attachment_fu

Question

I see there is a :user_ssl option in attachment_fu which checks the amazon_s3.yml file in order to serve files via https://

In the s3_backend.rb you have this method:

    def self.protocol
      @protocol ||= s3_config[:use_ssl] ? 'https://' : 'http://'
    end

But this then makes it serve ALL s3 attachments with SSL. I'd like to make it dynamic depending if the current request was made with https:// i.e:

  if request.ssl?
    @protocol = "https://"
  else
    @protocol = "http://"  
  end

How can I make it work in this way? I've tried modifying the method and then get the NameError: undefined local variable or method `request' for Technoweenie::AttachmentFu::Backends::S3Backend:Module error

Answer 1

The problem is that the method you're modifying (Technoweenie::AttachmentFu::Backends::AWS::S3.protocol) is static and does not have access to the file or request in question. The one you want to modify is Technoweenie::AttachmentFu::Backends::AWS::S3#s3_url(thumbnail). You'll have to add an options argument so your controller can pass in whether it wants SSL or not, since this model-level package has no understanding of controller-level issues like "current request" (nor should it).

The real answer, though, is "you probably don't want to do this." If the customer is saying something like "we have a freemium model wherein only our paying customers get SSL transfers of their photos," you should push back: "it's actually harder to cripple SSL file transfers, and it's likely to just introduce bugs down the road. Let's think of another freemium option to offer." If the customer doesn't really care, you might as well just turn SSL on for all uploads.

Answer 2

This is significant issue that needs to be solved correctly, or the implications are quite nasty (particularly if you don't test in IE, the errors and warnings may slip by you). My solution is to put the following in ApplicationController

around_filter :set_attachment_fu_protocol

def set_attachment_fu_protocol
  protocol = Technoweenie::AttachmentFu::Backends::S3Backend.instance_variable_get(:@protocol)
  Technoweenie::AttachmentFu::Backends::S3Backend.instance_variable_set(:@protocol, request.protocol)
  yield
ensure
  Technoweenie::AttachmentFu::Backends::S3Backend.instance_variable_set(:@protocol, protocol)
end

This solution was designed to have the following properties:

• Doesn't require patching attachment_fu
• Sets the protocol for S3 Backend per request
• Resets the protocol even if an exception occurs
• Preserves the default :use_ssl setting if you are running from the console
• Doesn't require the around_filter to be universal since it always resets it to the original state after each request