Rails 3.2.x: Serving files with nginx using X-Accel-Redirect header (capistrano deploy) (2. method)

serving_files_with_nginx2.txt

# Assumptions:
 
* Rails 3.2.x
* nginx
* capistrano deploy
* "X-Accel-Mapping header missing" messages in nginx error.log file
* You want to serve static files with nginx instead of Rails
 
# nginx configuration:

# This is required but the path and url is not important
passenger_set_cgi_param HTTP_X_ACCEL_MAPPING "/home/user/rails_app/shared/xyz/=/abc/";

location ~ ^/home/user/rails_app/releases/\d+/files/(\d\d\d)/(\d\d\d)/(\d\d\d)/(.*)$ {
  alias /home/user/rails_app/shared/files/$1/$2/$3/$4;
  internal;
}
 
# DocumentsController:
def index
  @document = Document.find(params[:id])
  # @document.path #=> /home/user/releases/20130111141529/files/000/000/001/file.txt
  send_file @document.path
end
 
# Rails: config/environments/production.rb
config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect'
 
# Request: 
http://localhost:3000/documents/1
 
# References:
 
* http://stackoverflow.com/questions/954470/serving-large-files-through-nginx-via-rails-2-3-using-x-sendfile
* http://airbladesoftware.com/notes/rails-nginx-x-accel-mapping
* http://wiki.nginx.org/HttpCoreModule#alias
* http://greenlegos.wordpress.com/2011/09/12/sending-files-with-nginx-x-accel-redirect/
* http://stackoverflow.com/questions/6237016/message-x-accel-mapping-header-missing-in-nginx-error-log