sysadmin.rb

class SysAdmin
  class Dsl
    def self.evaluate(file)
      builder = new
      builder.instance_eval(file.read, "config", 1)
      builder.to_definition
    end

    def initialize
      @servers = []
    end

    def server(name, spec)
      @servers << {:name => name, :spec => spec}
    end

    def to_definition
      Definition.new(@servers)
    end
  end

  class Definition
    attr_accessor :servers
    def initialize(servers)
      @servers = servers
    end

    def self.from_file(file)
      Dsl.evaluate(file)
    end
  end

  def self.load(file)
    @@definition = Definition.from_file(file)
  end

  def self.servers
    @@definition.servers
  end
end

if $0 == __FILE__
  require "test/unit"

  class TestSysAdmin < Test::Unit::TestCase
    def test_parsing
      SysAdmin.load(DATA)
      p SysAdmin.servers
    end
  end
end

__END__
# servers.rb
server 'client.project.prod.app1', '192.168.1.128'
server 'client.project.prod.app2', '192.168.1.129'
server 'client.project.prod.db1',  '192.168.1.130'
server 'client.project.prod.db2',  '192.168.1.131'
server 'client.project.stag.app1', '192.168.1.132'
server 'client.project.stag.app2', '192.168.1.133'
server 'client.project.stag.db1',  '192.168.1.134'
server 'client.project.stag.db2',  '192.168.1.135'