How to write a DRY, modular nginx conf (reverse proxy) with named locations

I'm using nginx mostly as a reverse cachining proxy in front of several gunicon/mod_wsgi applications and of course to server static files. I find that quickly my nginx confs become impossible to maintain; the issue is that I have a few patterns that are similar (or even identical) but I can't manage to make it clean. One of the biggest issues I have is that I would love to use named locations as

[nakimura]

mapを使えと

[Hash]

nginxのmapを使って共通設定をまとめる. hackだ