Flagon

Flagon is a storage agnostic feature flag gem. You can use flagon if you have features in your program that you'd like to be able to turn on or off using environment variables, a yaml file, a simple hash on initialization or a custom storage method you create yourself and pass in.

Initialising

You can initialize flagon using either a filename, a hash of settings or nothing if you'd like it to check environment variables.

Using Environment Variables

Flagon.init

Environment variables should be "on" or anything else to be off.

export MY_FLAG='on'

Using a Yaml Settings File

loader = Flagon.file_loader "/path/to/settings.yaml"
Flagon.init loader

The yaml file format should be single level, with values of on or off. E.g.

feature_1: on
feature_2: off

Using a Settings Hash

loader = Flagon.hash_loader {feature_1: "on", feature_2: "off"}
Flagon.init loader

Usage

You can use flagon in two ways. By checking the flag directly, or by passing a block.

Checking the flag

profit! if Flagon.enabled?(:feature_1)

Passing a block

Flagon.when_enabled(:feature_1) do
  profit!
end

Using the inspector directly

When you call Flagon.init an inspector object is returned. The class methods above are just convenience methods that call this inspector so you can also use it directly if that's your cup of tea.

ENV['BACON'] = 'on'
flagon = Flagon.init
flagon.enabled?(:bacon) # => true