Paperclip attachment not using proper updated_at time for query string

amazon-cloudfront, amazon-s3, paperclip, ruby-on-rails

Solution

It looks like this might have been a bug with earlier versions of Paperclip (I'm on 2.7) as it works on future versions.

For reference this is how I got it working. In the after_update on my model I force refreshed the instance as follows:

image.instance_write(:updated_at, Time.now.utc)
self.send(:update_without_callbacks)

I had to do `update_without_callbacks` so that it wouldn't get stuck in an infinite loop in the callback.

Now the `updated_at` time on the Attachment is updated, forcing refresh on Cloudfront.

Problem

I'm using Rails + Paperclip + S3. I'm looking to host my assets to Cloudfront using one of my S3 buckets. I know that Cloudfront caches assets but that you can break that cache by configuring it to forward query strings from the origin. When I modify an asset I expect this to happen - The `updated_at` timestamp of the ActiveRecord object is updated. - Paperclip updates the query string of the image on S3 to reflect the new `updated_at` time. - Cloudfront serves the new image because of the new timestamp query string. However, it looks like Paperclip isn't properly updating the `updated_at` timestamp. Maybe it's cached somehow. Therefore the query string doesn't update and Cloudfront never breaks the cache. My model is: ``` class UserImage < ActiveRecord::Base has_attached_file :image end >> ui = UserImage.find(576925) >> ui.image.class => Paperclip::Attachment >> ui.touch >> ui.updated_at.to_i => 1386241041 >> ui.image.updated_at => 1386240937 ``` Those two updated_at timestamps should be the same.

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