wip: fixing up railtie middleware install

Gemfile

@@ -15,3 +15,4 @@ gem "rack-test", "~> 1.1"
 
 # for testing the rack middleware
 gem "opentelemetry-instrumentation-rack", "0.20.2"
+gem "opentelemetry-instrumentation-action_pack", "0.1.4"

lib/splunk/otel/instrumentation/action_pack.rb

@@ -1,3 +1,13 @@
 # frozen_string_literal: true
 
+module Splunk
+  module Otel
+    module Instrumentation
+      # Contains the RUM instrumentation for the ActionPack gem
+      module ActionPack
+      end
+    end
+  end
+end
+
 require_relative "./action_pack/railtie"

lib/splunk/otel/instrumentation/action_pack/instrumentation.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module Splunk
+  module Otel
+    module ActionPack
+      # The Instrumentation class contains logic to detect and install the ActionPack instrumentation
+      class Instrumentation < OpenTelemetry::Instrumentation::Base
+        MINIMUM_VERSION = Gem::Version.new('5.2.0')
+
+        install do |_config|
+          require_railtie
+        end
+
+        present do
+          defined?(::ActionController)
+        end
+
+        compatible do
+          gem_version >= MINIMUM_VERSION
+        end
+
+        option :enable_recognize_route, default: false, validate: :boolean
+
+        private
+
+        def gem_version
+          ::ActionPack.version
+        end
+
+        def require_railtie
+          require_relative 'railtie'
+        end
+      end
+    end
+  end
+end

lib/splunk/otel/instrumentation/action_pack/railtie.rb

@@ -2,14 +2,16 @@
 
 module Splunk
   module Otel
-    module ActionPack
-      # Install the Rack middleware for RUM responses
-      class Railtie < ::Rails::Railtie
-        config.before_initialize do |app|
-          app.middleware.insert_before(
-            0,
-            Splunk::Otel::Rack::RumMiddleware
-          )
+    module Instrumentation
+      module ActionPack
+        # Install the Rack middleware for RUM responses
+        class Railtie < ::Rails::Railtie
+          config.before_initialize do |app|
+            app.middleware.insert_before(
+              0,
+              Splunk::Otel::Rack::RumMiddleware
+            )
+          end
         end
       end
     end

lib/splunk/otel/instrumentation/action_pack/version.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+module Splunk
+  module Otel
+    module ActionPack
+      VERSION = '0.1.0'
+    end
+  end
+end

test/splunk/instrumentation/rails_test.rb

@@ -5,8 +5,11 @@
 require "test_helper"
 require "opentelemetry/sdk"
 require "opentelemetry/instrumentation/rack"
+require "opentelemetry/instrumentation/action_pack"
 require "splunk/otel"
 require "splunk/otel/instrumentation/rack"
+require "splunk/otel/instrumentation/action_pack"
+require "splunk/otel/instrumentation/action_pack/railtie"
 require "rack/test"
 require 'test_helpers/app_config.rb'
 
@@ -20,7 +23,8 @@ class RumRailsTest < Test::Unit::TestCase
     def setup
       with_env("OTEL_SERVICE_NAME" => "test-service") do
         Splunk::Otel.configure do |c|
-            c.use 'OpenTelemetry::Instrumentation::ActionPack'
+          c.use "OpenTelemetry::Instrumentation::ActionPack"
+          # c.use "Splunk::Otel::Instrumentation::ActionPack"
         end
       end
     end