lib/ndr_stats/railtie.rb in ndr_stats-0.2.1 vs lib/ndr_stats/railtie.rb in ndr_stats-0.2.2

@@ -1,15 +1,38 @@
 module NdrStats
   # Behaviour that runs when this gem is used in the context of a Rail app.
   class Railtie < Rails::Railtie
+    class << self
+      def config_values
+        config_from_file.merge(config_from_env)
+      end
+
+      private
+
+      def config_from_file
+        config_file = Rails.root.join('config/stats.yml')
+        return {} unless File.exist?(config_file)
+
+        YAML.load_file(config_file).symbolize_keys
+      end
+
+      def config_from_env
+        config = {}
+
+        ENV.each do |key, value|
+          next unless key =~ /\ANDR_STATS_(.*)/
+
+          config[Regexp.last_match(1).downcase.to_sym] = value
+        end
+
+        config
+      end
+    end
+
     # Auto-configures NdrStats with config in the host app, if found.
     config.after_initialize do
-      config_file = Rails.root.join('config', 'stats.yml')
-      next unless File.exist?(config_file)
-
-      config = YAML.load_file(config_file).symbolize_keys.
-               slice(:host, :port, :system, :stack).
-               reject { |_, value| value.blank? }
+      config = Railtie.config_values.slice(:host, :port, :system, :stack)
+      next if config.empty?
 
       # Try and derive system/stack from applications that expose it:
       app_class = Rails.application.class
       host_module = app_class.try(:module_parent) || app_class.parent
       config[:system] ||= host_module.try(:flavour) || host_module.name.downcase