Weak ETAGs in Rails?

Question

What is the best way to tell rails to use weak instead of strong ETAGs when using methods fresh_when and stale??

The reason I ask is that nginx (correctly) removes strong ETAG headers from responses when on-the-fly gzipping is enabled.

Answer 1

I took the code from @grosser's answer and turned it into a Gem:

• https://rubygems.org/gems/rails_weak_etags
• https://github.com/johnnaegle/rails_weak_etags

You can just add this to your gemfile:

gem 'rails_weak_etags'

And it will be installed into your middleware before Rack::ConditionalGet:

> bundle exec rake middleware
....
use RailsWeakEtags::Middleware
use Rack::ConditionalGet
use Rack::ETag
....

Then all the e-tags generated by rails, either with Rack::ETag or with explicit e-tags will be converted to weak. Using a patched, or version > 1.7.3 of nginx, will then let you use e-tags and gzip compression.

RACK 1.6 defaults etags to weak - this gem is no longer helpful if you upgrade.