Config helps you easily manage environment specific settings in an easy and usable manner.

• simple YAML config files
• config files support ERB
• config files support inheritance
• access config information via convenient object member notation

• Ruby 2.x
• Rails >= 3.1 and 4
• Padrino
• Sinatra

For older versions of Rails and other Ruby apps, use AppConfig.

Add this to your Gemfile:

gem "config"

If you want to use Settings before rails application initialization process you can load Config railtie manually:

module Appname
  class Application < Rails::Application

    Bundler.require(*Rails.groups)
    Config::Integration::Rails::Railtie.preload

    # ...

    config.time_zone = Settings.time_zone

    # ...

  end
end

Add this to your Gemfile:

gem "config"

in your app.rb, you'll also need to register Config

register Config

Add this to your Gemfile:

gem "config"

in your app, you'll need to register Config. You'll also need to give it a root so it can find the config files.

set :root, File.dirname(__FILE__)
register Config

It's also possible to initialize it manually within your configure block if you want to just give it some yml paths to load from.

Config.load_and_set_settings("/path/to/yaml1", "/path/to/yaml2", ...)

You may customize the behavior of Config by generating an initializer file:

rails g config:install

This will generate config/initializers/config.rb with a set of default settings as well as to generate a set of default settings files:

config/settings.yml
config/settings/development.yml
config/settings/production.yml
config/settings/test.yml

After installing this plugin, the Settings object will be available globally. Entries are accessed via object member notation:

Settings.my_config_entry

Nested entries are supported:

Settings.my_section.some_entry

Alternatively, you can also use the [] operator if you don't know which exact setting you need to access ahead of time.

# All the following are equivalent to Settings.my_section.some_entry
Settings.my_section[:some_entry]
Settings.my_section['some_entry']
Settings[:my_section][:some_entry]

If you have set a different constant name for the object in the initializer file, use that instead.

Config entries are compiled from:

config/settings.yml
config/settings/#{environment}.yml
config/environments/#{environment}.yml

config/settings.local.yml
config/settings/#{environment}.local.yml
config/environments/#{environment}.local.yml

Settings defined in files that are lower in the list override settings higher.

You can reload the Settings object at any time by running Settings.reload!.

You can also reload the Settings object from different config files at runtime.

For example, in your tests if you want to test the production settings, you can:

Rails.env = "production"
Settings.reload_from_files(
  Rails.root.join("config", "settings.yml").to_s,
  Rails.root.join("config", "settings", "#{Rails.env}.yml").to_s,
  Rails.root.join("config", "environments", "#{Rails.env}.yml").to_s
)

You can have environment specific config files. Environment specific config entries take precedence over common config entries.

Example development environment config file:

#{Rails.root}/config/environments/development.yml

Example production environment config file:

#{Rails.root}/config/environments/production.yml

If you want to have local settings, specific to your machine or development environment, you can use the following files, which are automatically .gitignored :

Rails.root.join("config", "settings.local.yml").to_s,
Rails.root.join("config", "settings", "#{Rails.env}.local.yml").to_s,
Rails.root.join("config", "environments", "#{Rails.env}.local.yml").to_s

You can add new YAML config files at runtime. Just use:

Settings.add_source!("/path/to/source.yml")
Settings.reload!

This will use the given source.yml file and use its settings to overwrite any previous ones.

On the other hand, you can prepend a YML file to the list of configuration files:

Settings.prepend_source!("/path/to/source.yml")
Settings.reload!

This will do the same as add_source, but the given YML file will be loaded first (instead of last) and its settings will be overwritten by any other configuration file. This is especially useful if you want to define defaults.

One thing I like to do for my Rails projects is provide a local.yml config file that is .gitignored (so its independent per developer). Then I create a new initializer in config/initializers/add_local_config.rb with the contents

Settings.add_source!("#{Rails.root}/config/settings/local.yml")
Settings.reload!

Note: this is an example usage, it is easier to just use the default local files settings.local.yml, settings/#{Rails.env}.local.yml and environments/#{Rails.env}.local.yml for your developer specific settings.

Embedded Ruby is allowed in the configuration files. See examples below.

Consider the two following config files.

• #{Rails.root}/config/settings.yml

size: 1
server: google.com

• #{Rails.root}/config/environments/development.yml

size: 2
computed: <%= 1 + 2 + 3 %>
section:
  size: 3
  servers: [ {name: yahoo.com}, {name: amazon.com} ]

Notice that the environment specific config entries overwrite the common entries.

Settings.size   # => 2
Settings.server # => google.com

Notice the embedded Ruby.

Settings.computed # => 6

Notice that object member notation is maintained even in nested entries.

Settings.section.size # => 3

Notice array notation and object member notation is maintained.

Settings.section.servers[0].name # => yahoo.com
Settings.section.servers[1].name # => amazon.com

Heroku uses ENV object to store sensitive settings which are like the local files described above. You cannot upload such files to Heroku because it's ephemeral filesystem gets recreated from the git sources on each instance refresh.

To use config with Heroku just set the use_env var to true in your config/initializers/config.rb file. Eg:

Config.setup do |config|
  config.const_name = 'AppSettings'
  config.use_env = true
end

Now config would read values from the ENV object to the settings. For the example above it would look for keys starting with 'AppSettings'. Eg:

ENV['AppSettings.section.size'] = 1
ENV['AppSettings.section.server'] = 'google.com'

It won't work with arrays, though.

To upload your local values to Heroku you could ran bundle exec rake config:heroku.

Bootstrap

$ appraisal install

Running the test suite

$ appraisal rspec

• Jacques Crocker

• Fred Wu

• Piotr Kuczynski

• Inherited from AppConfig by Christopher J. Bottaro

Config is released under the MIT License.