Add the ability of returning arbitrary headers to ActionDispatch::Static

Now ActionDispatch::Static can accept HTTP headers so that developers
will have control of returning arbitrary headers like
'Access-Control-Allow-Origin' when a response is delivered. They can
be configured through `#config.public_file_server.headers`:

  config.public_file_server.headers = {
    "Cache-Control"               => "public, max-age=60",
    "Access-Control-Allow-Origin" => "http://rubyonrails.org"
  }

Also deprecate `config.static_cache_control` in favor of
`config.public_file_server.headers`.

1 files changed, 4 insertions, 1 deletions

diff --git a/railties/lib/rails/application/default_middleware_stack.rb b/railties/lib/rails/application/default_middleware_stack.rb
index 6f9ccec137..6c0b60f1ec 100644
--- a/railties/lib/rails/application/default_middleware_stack.rb
+++ b/railties/lib/rails/application/default_middleware_stack.rb
@@ -18,7 +18,10 @@ module Rails
           middleware.use ::Rack::Sendfile, config.action_dispatch.x_sendfile_header
 
           if config.serve_static_files
-            middleware.use ::ActionDispatch::Static, paths["public"].first, config.static_cache_control, index: config.static_index
+            headers = config.public_file_server.headers || {}
+            headers['Cache-Control'.freeze] = config.static_cache_control if config.static_cache_control
+
+            middleware.use ::ActionDispatch::Static, paths["public"].first, index: config.static_index, headers: headers
           end
 
           if rack_cache = load_rack_cache