Configuration library for ruby with YAML/JSON/TOML backends with unified object access


 % gem install asetus



require 'asetus'
cfg  = Asetus.cfg
port = cfg.server.port
user = cfg.auth.user
pw   = cfg.auth.password

It tried to detect your software name via caller_locations if no ':name' argument was given. It automatically loads /etc/name/config and ~/.config/name/config and merges them together.


require 'asetus'
asetus = name:    'mykewlapp',
                    default: {'poop'=>'xyzzy'},
                    adapter: 'yaml',
                    usrdir:  '/home/app/config/',
                    sysdir:  '/System/config/',
                    load:    false
asetus.default.poop2 = [1, 2, 3, 4]
asetus.default.starship.poopoers = 42
asetus.load :user
if asetus.user.empty?
  asetus.user = asetus.default :user
asetus.load    # load+merges cfg, takes argument :default, :system, :user
asetus.cfg     # merged default + system + user  (merged on load)
asetus.default # default only
asetus.system  # system only
asetus.user    # user only

Reserved methods

  • each - iterate all config keys in current level
  • has_key?(arg) - check if current level has key arg
  • [arg] - fetch arg (useful for non-literal retrieval, instead of using #send)
  • key? - all keys have question mark version reserved, checks if key exists+true (true), exists+false (false), not-exists (nil)
  • all object class methods


  • should I add feature to raise on unconfigured/unset?
  • should I always merge to 'cfg' when default/system/config is set?

Copyright 2014-2015 Saku Ytti [email protected]

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.