site_config is a little plugin that addresses a problem lots of people seem to need to solve in their Rails apps: per-environment configuration variables.

It’s very simple, but makes configuration dead-easy. To install it:

script/plugin install git://github.com/cheald/site_config.git

Once you have it installed, check out config/site_config.yml - there’s your config file.

You’ll notice that it has some dummy data in there to begin with. It’s much like your database.yml file; just specify the environment, and under that, specify the key:value pairs you want to have available in your app. site_config has one little trick up its sleeve, though - the key “inherit” is special, and tells it to pull values from another environment. This helps you DRY up your configs, and makes it quite easy to maintain.

For example, if you had the following site_config.yml:

development:
  page_title: "my development site"
  admin_user: chris

production:
  inherit: development
  page_title: "my production site"

You can then use those configured values in your site like so:

<title><%=config_option :page_title %></title>
Your friendly admin is <%=config_option :admin_user %>

site_config will pull values defined for your current environment. If you don’t have a value defined for a given environment, but do have an inherit defined, site_config will then look to the inherited config to pull values from.

Additionally, if you want a value from a specific environment, config_option accepts a second parameter, which specifies the environment to pull from.

config_option :page_title, :development

There’s more at the github page. Check it out.