How to install gem with additional configuration using bundler?

I am implementing a geolocation library that requires the following gem installation

sudo gem install geoip_city -- --with-geoip-dir=/opt/GeoIP

I'm unsure of how I can add this to my Gemfile.

When I push/deploy on my production 开发者_开发百科server, how can I link the gem to the geoip lib there as well?

If it makes a difference, I could probably use ./configure --prefix=/path/to/my_app/lib/ so that the C lib was installed directly inside my Rails 3 app. Or would this be advised against?

From about 3/4 of the way down this page on the Bundler website:

If you really need to pass flags to a C extension, you can use the bundle config command:

$ bundle config build.mysql --with-mysql-config=/usr/local/mysql/bin/mysql_config

Bundler will store this configuration in ~/.bundle/config, and bundler will use the configuration for any bundle install performed by the same user. As a result, once you specify the necessary build flags for a gem, you can successfully install that gem as many times as necessary.