Made app configurable without modifying any files

Settings are loaded from the file pointed to by the SETTINGS_PATH
environment variable. That file contains the location of all settings,
including a path for the database configuration and for logging.

This allows the executor of this application to customize all settings
without creating or modifying any files within the application.

app/controllers/v2/base_controller.rb

@@ -5,7 +5,7 @@ class V2::BaseController < ApplicationController
 
   def authenticate
     authenticate_or_request_with_http_basic do |_, password|
-      password == ENV['AUTH_TOKEN']
+      password == Settings.auth_token
     end
   end
 end

config/application.rb

@@ -11,6 +11,8 @@
 # you've limited to :test, :development, or :production.
 Bundler.require(:default, Rails.env)
 
+require File.expand_path('../../lib/settings', __FILE__)
+
 module CfMysqlBroker
   class Application < Rails::Application
     # Settings in config/environments/* take precedence over those specified here.
@@ -30,6 +32,8 @@ class Application < Rails::Application
 
     config.autoload_paths += %W(#{config.root}/lib)
     config.autoload_paths += Dir["#{config.root}/lib/**/"]
+
+    config.paths.add 'config/database', with: Settings.database_config_path
+    config.paths.add 'log', with: Settings.log_path
   end
 end
-

config/database.yml

@@ -1,3 +1,7 @@
+# This file should not be used in deployed environments. Instead, the
+# application configuration file specified by SETTINGS_PATH should
+# include the path to a database configuration that includes these
+# settings.
 
 development:
   adapter: mysql2

config/settings.yml

@@ -0,0 +1,14 @@
+# This file should not be used in deployed environments. Instead, set
+# the SETTINGS_PATH environment variable to point to a configuration
+# file that contains these settings.
+
+defaults: &defaults
+  database_config_path: 'config/database.yml'
+  log_path: 'log/<%= Rails.env %>.log'
+  auth_token: 'secret'
+
+development:
+  <<: *defaults
+
+test:
+  <<: *defaults

lib/settings.rb

@@ -0,0 +1,6 @@
+ENV['SETTINGS_PATH'] ||= File.expand_path('../../config/settings.yml', __FILE__)
+
+class Settings < Settingslogic
+  source ENV['SETTINGS_PATH']
+  namespace Rails.env
+end

spec/support/controller_helpers.rb

@@ -1,19 +1,9 @@
 module ControllerHelpers
   extend ActiveSupport::Concern
 
-  included do
-    before do
-      @__original_auth_token, ENV['AUTH_TOKEN'] = ENV['AUTH_TOKEN'], 'secret'
-    end
-
-    after do
-      ENV['AUTH_TOKEN'], @__original_auth_token = @__original_auth_token, nil
-    end
-  end
-
   def authenticate
     username = 'test'
-    password = 'secret'
+    password = Settings.auth_token
 
     request.env['HTTP_AUTHORIZATION'] = ActionController::HttpAuthentication::Basic.encode_credentials(username, password)
   end

spec/support/request_helpers.rb

@@ -4,21 +4,13 @@ module RequestHelpers
   included do
     let(:default_env) do
       username = 'test'
-      password = 'secret'
+      password = Settings.auth_token
 
       {
         'HTTP_AUTHORIZATION' => ActionController::HttpAuthentication::Basic.encode_credentials(username, password)
       }
     end
     let(:env) { default_env }
-
-    before do
-      @__original_auth_token, ENV['AUTH_TOKEN'] = ENV['AUTH_TOKEN'], 'secret'
-    end
-
-    after do
-      ENV['AUTH_TOKEN'], @__original_auth_token = @__original_auth_token, nil
-    end
   end
 end