Using CDN with Rails assets

Using CDN (Content Delivery Network) server to serve assets (images and other static files like css, js) on Rails is very easy with assets pipeline.

Change config in production.rb:

[codesyntax lang=”rails”]

# serve all assets from CDN server
config.action_controller.asset_host = 'http://cdn.mydomain.com'

#or if your files in a folder on CDN server
config.action_controller.asset_host = 'http://cdn.mydomain.com/myfolder'

[/codesyntax]

To use CDN server only for images (but not for stylesheets or javascripts):

[codesyntax lang=”rails”]

# serve only images
config.action_controller.asset_host = Proc.new { |source|
if source =~ /\b(.png|.jpg|.gif)\b/i
"http://cdn.mydomain.com"
end
}

[/codesyntax]

Examples on github:

https://gist.github.com/maxivak/5239159

For more flexible settings you can use this gem: https://github.com/cmer/rails-assets-cdn