Are there any basic templating preprocessors that I can use for nginx configuration files?

I've been using nginx variables to simplify my templates for a few years now. It turns out this is apparently a "rather slow" way of doing things and that my static configuration should be static.

With this in mind I would like to change to a situation where I have a nginx.conf.template file (or something like that) which I can run a command against —on my server— to generate a real configuration file.

My requirements are really simple:

• Simple variable substitution. So I can have [something like]:

  SITE=oli
  DOMAIN=oli.example.com
  ------
  server { server_name ##DOMAIN##; ssl on; ssl_certificate /web/##SITE##/ssl/##DOMAIN##.crt; ssl_certificate_key /web/##SITE##/ssl/##DOMAIN##.key;
  ...

  I have to stress that the syntax above is completely made up on the spot. Just an example of how I'd imagine doing this.

• Includes. Pull a file in AND (that's super-extra-important) also perform substitution.

• Something simple. I'm lazy and I hate configuration. m4 looks lovely and all but zomg, I don't want to learn a new language just to configure a server. I'd rather just set the nginx manually if that's the trade-off.

This isn't specific to nginx, but that's what I'm using it for here. I'm just looking for a nice, simple command-line templating preprocessor. What have we got?

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