GitStaticAssets

application.sass

.arrow
  background: asset_path('/images/arrow_small_white.png') no-repeat 14px center

git_static_assets.rb

module GitStaticAssets
  def asset(path)
    if ENV["RACK_ENV"] == "production"
      sha = `git rev-parse --short HEAD:public#{path}`.strip
      "/asset-#{sha}#{path}"
    else
      path
    end
  end
end
module Sass::Script::Functions
  include GitStaticAssets
  def asset_path(path)
    assert_type path, :String
    Sass::Script::String.new("url(#{asset(path.value)})")
  end
  declare :asset_path, :args => [:string]
end
Cuba.plugin GitStaticAssets

layout.haml

-# Just the important bits
- Dir["public/js/vendor/jquery*.js"].each do |js|
  %script{type: "text/javascript", src: asset(js.sub("public", ""))}

nginx.conf

# For use with latest commit SHA1
location ^~ /asset {
  expires max;
  rewrite "^/asset-([a-z0-9]+)/(.*)" /$2 break;
}