Rails MultiSite App + nginx config

I'm trying to deploy a multisite Rails app with different views and public folders for each site. Let's say that we have www.foo.com and www.bar.com. Inside my RAILS_ROOT directory I have a [sites] directory with two folders inside [foo] and [bar] each folder consists of a [public] and [views] folder.

My nginx configuration has to be something like that:

server {
      listen 80;
      server_name www.foo.com;
      root RAILS_ROOT/sites/bar/public;
      passenger_enabled on;
      rails_env development;
}


server {
      listen 80;
      server_name www.bar.com;
      root RAILS_ROOT/sites/bar/public;
      passenger_enabled on;
      rails_env development;
}

My problem is that nginx can't actually find RAILS_ROOT as it 开发者_运维技巧expects a usual hierarchy for the public folder RAILS_ROOT/public. Any solution for this?

When I referer to RAILS_ROOT I don't mean the variable I use it instead of writing a specific path .../.../