Re-evaluated how we use Umpire today, I think we should consider moving from lighttpd to nginx, because:
 - Dome also uses nginx. Having only one httpd server simplified factory server.
 - nginx has good proxy ability, which will be helpful for shopfloor proxy service in future.
 - nginx today is more powerful with better performance than the time we started umpire, especially for netboot download.
 - nginx supports fastcgi but not CGI, but our Umpire also only uses fastcgi now.
 - building nginx is more painful in portage, but we're now building under Docker, also nginx ebuild file is now also available.

Taking all these into consideration, I think we should try to replace the lighttpd inside Umpire by nginx.

This is a very low priority item.