This is a DataMapper adapter to DataStore of Google App Engine.
This adapter is designed to be used with JRuby.
First of all, you must install Google AppEngine SDK and configure its environment. After that, you can install this adapter by gem command like this.
sudo gem install dm-datastore-adapter
In your config/database.yml,
production:
:adapter: datastore
:host: localhost
You shouldn't use this adapter for environments other than production environment.