Merge pull request #13 from jcolbyfisher/opt-out-of-web-collector

opt-out flag for automatic web instrumentation

Author: mattolson

README.md

@@ -49,6 +49,7 @@ After requiring the main file, you can further configure with:
 | server_port | The port to run the exporter on | `9394` | `ENV['PROMETHEUS_SERVER_PORT']` |
 | server_thread_pool_size | The number of threads used for the exporter server | `3` | `ENV['PROMETHEUS_SERVER_THREAD_POOL_SIZE']` |
 | process_name | What the current process name is (used in logging) | `"unknown"` | `ENV['PROCESS']` |
+| railtie_disabled | Opt out flag for Railtie; use `Bigcommerce::Prometheus::Instrumentors::Web.new(app: Rails.application).start` in your app's code to start it up yourself  | `0` | `ENV['PROMETHEUS_DISABLE_RAILTIE']` |
 
 ## Custom Collectors
 

lib/bigcommerce/prometheus/configuration.rb

@@ -51,7 +51,10 @@ module Configuration
         resque_collectors: [],
         resque_type_collectors: [],
         web_collectors: [],
-        web_type_collectors: []
+        web_type_collectors: [],
+
+        # Additional configuration
+        railtie_disabled: ENV.fetch('PROMETHEUS_DISABLE_RAILTIE', 0).to_i.positive?
       }.freeze
 
       attr_accessor *VALID_CONFIG_KEYS.keys

lib/bigcommerce/prometheus/integrations/railtie.rb

@@ -23,7 +23,7 @@ module Integrations
       #
       class Railtie < ::Rails::Railtie
         initializer 'zzz.bc_prometheus_ruby.configure_rails_initialization' do |app|
-          Bigcommerce::Prometheus::Instrumentors::Web.new(app: app).start
+          Bigcommerce::Prometheus::Instrumentors::Web.new(app: app).start unless ::Bigcommerce::Prometheus.railtie_disabled
         end
       end
     end