Serving only font assets directly from app server - ruby-on-rails

Question

In my rails app I am serving all my assets through a CDN. I'd like to serve only my fonts directly from my app server. font_url/font-url will always include the the cdn url. Is there any convenient way to generate the path to the font (with digest) without the CDN domain or the protocol (http[s]) included?
The only thing I can think of is writing my own method that replicates the functionality of asset_path -- hopefully there is a more elegant way to achieve this.
update -- backgroun
I want to serve fonts from my main domain only to IE users so they don't break when in "high security" mode.
How to serve fonts from different servers for IE users?
IE conditional comments with Sass and Bourbon

Answer 1

Update:
Copy the font files into a separate folder, say "ie-high-security" for example. This is to identify them in step #2.
Serve files in the folder ("ie-high-security" in the example) by configuring the asset_host in "config/application.rb":
ActionController::Base.asset_host = Proc.new { |source|
if source.include?('/ie-high-security/')
""
else
"http://assets.example.com"
end
}
Reference the fonts in the "ie-high-security" folder in a separate stylesheet intended only for IE9.
Serve the IE9 stylesheet with conditional comments as suggested in https://stackoverflow.com/a/25415002/368697:
<!--[if IE 9]>
stylesheet using internally served fonts
<![endif]-->
Old suggestion:
Use font_path instead of font_url. The first method generates an absolute path without the asset host prepended.
If the font is being included from a stylesheet that is served from your CDN, you'll need a full path back to the app server though.