% cat egi.conf
env(:development) {
  item :vhost0301, { :tags => [ :mysqld, :rails ] }
}
env(:production) {
  group(:mysqld) {
    item :vhost0421, { :tags => [ :master ] }
    item :vhost0422
  }

  # you can define item without group
  item :vhost0423, { :tags => [ :rails ] }
}
% EGI_ENV=production irb
> require 'egi'
> # find by group or tag
> Egi.env.mysqld #=> [ { :name => :vhost0421, :tags => [ :mysqld, :master ] },
                       { :name => :vhost0422, :tags => [ :mysqld ] }
                     ]
> Egi.env.master #=> [ { :name => :vhost0421, :tags => [ :mysqld, :master ] } ]
> # fetch by name
> Egi.env.vhost0423 #=> { :name => :vhost0423, :tags => [ :rails ]}, 
% EGI_ENV=development irb
> require 'egi'
> Egi.env.mysqld #=> [ { :name => :vhost0301, :tags => [ :mysqld, :rails ] } ]
# can not fetch other envs
> Egi.env.vhost0421 #=> nil

env(name, &block)

group(name, &block)

item(name, hash)