Add preprovision initializer for app platforms

CHANGELOG.md

@@ -1,4 +1,5 @@
 v4.12.0 (XXXX 2024)
+  - Add preprovision initializer for app platforms
   - Update Dradis links in README
   - Fix the TypeError around the plugins template caching
 

lib/dradis/plugins/engine.rb

@@ -5,11 +5,34 @@ class Engine < ::Rails::Engine
 
       config.dradis = ActiveSupport::OrderedOptions.new
 
-      initializer "dradis-plugins.set_configs" do |app|
+      initializer 'dradis-plugins.set_configs' do |app|
         options = app.config.dradis
         options.base_export_controller_class_name ||= 'AuthenticatedController'
         options.thor_helper_module ||= Dradis::Plugins::ThorHelper
       end
+
+      # In App Platforms, assets:precompile is run before the DB is provisioned causing a
+      #   ActiveRecord::ConnectionNotEstablished: connection to server at "127.0.0.1",
+      #   port 5432 failed: Connection refused
+      #
+      # We run into this problem because dradis-plugins uses a :enabled/disabled DB
+      # setting for each integration to decide whether to load them or not.
+      #
+      # See:
+      #   https://devcenter.heroku.com/articles/rails-asset-pipeline
+      #
+      initializer 'dradis-plugins.preprovision-database' do
+        Rails.application.reloader.to_prepare do
+          # This is set by the App Platforms
+          if ENV['DATABASE_URL']
+            # DB isn't ready yet
+            if !(ActiveRecord::Base.connection rescue false)
+              # Empty the list of integrations.
+              Dradis::Plugins::class_variable_set('@@enabled_list', [])
+            end
+          end
+        end
+      end
     end
   end
 end