First, thanks to all those who work on Nginx. It's a fantastic web server and has made my life easier in many ways.

Technical details: Using Nginx 0.5.19 with Mongrel and Ruby on Rails

My problem is that content sent with X-Accel-Redirect doesn't send a Content-Length header. I'm sending 100-200 MB files and it would be nice if the client can have a progress bar to tell them how much there is left to download. Without the Content-length header, they just see "10 MB of ? remaining" in the web browser.

I tried sending a Content-length header from my Rails app with the X-Accel-Redirect header, but it seems to be stripped out of the headers when sent to the client. I also tried adding the header manually in the nginx.config, but it's always sends 0.

add_header Content-Length $content_length;

My last resort was to hard-code a reasonable value for the Content-Length

add_header Content-Length 150000000;

This works, but isn't optimal.

Can anyone recommend a good way to do this?