S3Fox/S3 ACL reversion

I use the Amazon S3 (Simple Storage Service) to host all the images on this blog. It's a great, cheap, reliable service. I use the S3Fox Firefox extension as an easy tool for interacting with S3. It lets you manage and upload content to your S3 account.

One of the features of S3 is the ACL, or "Access control list". This controls who can do what to your content. For any file on your S3 account, you can allow Read, Write or FullControl for Everyone, Authenticated Users, or your own account. The default is to turn on FullControl for your own account and turn off everything for everyone else.

(Note here the red arrow pointing to some kind of weird leaking of the background image)

I've found that generally when you update a file using S3Fox the previous ACL settings for that file or directory are retained. However, sometimes, for reasons I haven't figured out, it reverts to the default ACL:



This is fairly annoying because I usually don't realize it until I refresh my blog and suddenly images are not loading. Trying to access a document in this state directly in the browser by URL gives you the following error:



I have no idea if this is an S3Fox or S3 problem. Either S3 sometimes forgets the ACL of a particular document when that document is updated, or S3Fox retrieves or sends the ACL information incorrectly.

Suggested Fixes for S3 or S3Fox

1. Always retain the previous ACL for a file when it is updated.


2. Fix the weird painting issue noted on the second image in this post.

Update: I added some additional information and emailed this post to the makers of S3fox - Thursday, December 2, 2010.