AppConfiguration

AppConfiguration is a very simple gem that helps you configure your Ruby applications. AppConfiguration uses YAML config files or environmental variales to set the configuration parameters.

Add this line to your application's Gemfile:

gem 'app_configuration'

And then execute:

$ bundle

Or install it yourself as:

$ gem install app_configuration

AppConfiguration comes with great default values. So if you want to setup a new config all you need to do is

config = AppConfiguration.new
my_configurable_variable = config.foo
my_other_variable = config['bar']

By default, when getting the variable foo AppConfiguration will look for the environmental variable FOO. If it cannot find it, AppConfiguration will look for the .config.yml file in the current working directory. If there is no config file there, it will try to find the .config.yml in your home directory.

A possible .config.yml for this example could look like this

foo: 'This is the foo variable'
bar: 'This is the bar variable'

AppConfiguration can be customized to fit your needs. Here is an example

config = AppConfiguration.new('.setup.yml') do
  base_local_path '/usr/local'
  base_global_path '/config'
  use_env_variables true
  prefix 'my_app'
end

You can set the configuration file name by passing the name to the new method or you can use the config_file_name method inside the configuration block.

• config_file_name Sets the name of the config file. Default .config.yml.
• base_local_path Sets the base path for the local configuration file. If there is no config file in this path it will look in the global configuration path. Default ./
• base_global_path Sets the base path for the global configuration file. Default ~/
• use_env_variables Flag that activates the use of enviromental variable. Default true
• prefix A prefix to be appended when looking for environmental variables. For example if prefix is set to my_app, when the foo variable is fetched, the MY_APP_FOO environmental variable will be checked. This is used to avoid name collitions. Default nil

You can retrieve a variable from a AppConfiguration::Config object by doing

foo = config.foo
foo = config['foo']

Environmental variables will be checked first, adding the necesary prefix if provided. If there is no environmental variable, the local config file will be checked. If there is no local file or a value has not been defined for the given variable, the global config file will be checked. Otherwise it returns nil.

If you create a new config object by using AppConfiguration.new, then you must keep the reference to this configuration. Instead you can registers a configuration by using AppConfiguration.for. Then you can obtain a configuration by using AppConfiguration[]. For example

AppConfiguration.for :github
# ... Then somewhere else ...
github = AppConfiguration[:github]
github.api_key

In the previous example the name of the configuration file is assumed to be .github.yml and all the environmental variables will be prefixed with GITHUB_. You can change this behaviour by passing a configuration block to the for method. For example if you want to change the local path you can register the configuration as follows

AppConfiguration.for :github do
  base_local_path Rails.root
end

To change the default local path and the default global path for all the AppConfiguration::Config objects all you need to do is

AppConfiguration::Config.default_local_path = Rails.root
AppConfiguration::Config.default_global_path = '/usr/configs'

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Please add specs for all new features. If you find a bug and an spec probing that the bug exists and in a separate commit add the bug fix.

Copyright (c) 2013 Guido Marucci Blas

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.