Send big file

host-name.conf

passenger_set_cgi_param HTTP_X_ACCEL_MAPPING /local/storage/=/storage/;
location /storage/ {
  internal;
  alias /local/storage/;
}

# From 'lib/rack/sendfile'
location ~ /storage/(.*) {
  internal;
  alias /local/storage/$1;
}

location / {
  proxy_redirect     off;
  proxy_set_header   Host                $host;
  proxy_set_header   X-Real-IP           $remote_addr;
  proxy_set_header   X-Forwarded-For     $proxy_add_x_forwarded_for;

  proxy_set_header   X-Sendfile-Type     X-Accel-Redirect;
  proxy_set_header   X-Accel-Mapping     /local/storage/=/storage/;
  proxy_pass         http://127.0.0.1:8080/;
}

production.rb

config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect'

starage_controllers.rb

# ... auth before
def uploads
  send_file "/local/storage/#{file_name}", :disposition => 'inline'
end