DI railtie

Author: p

Steepfile

@@ -145,6 +145,7 @@ target :datadog do
   ignore 'lib/datadog/core/workers/queue.rb'
   ignore 'lib/datadog/core/workers/runtime_metrics.rb'
   ignore 'lib/datadog/di/configuration/settings.rb'
+  ignore 'lib/datadog/di/contrib/railtie.rb'
   ignore 'lib/datadog/kit/appsec/events.rb' # disabled because of https://github.com/soutaro/steep/issues/701
   ignore 'lib/datadog/kit/identity.rb'      # disabled because of https://github.com/soutaro/steep/issues/701
   ignore 'lib/datadog/opentelemetry.rb'

integration/apps/rails-seven/app/controllers/di_controller.rb

@@ -0,0 +1,6 @@
+class DiController < ApplicationController
+  def ar_serializer
+    test = Test.create!
+    render json: Datadog::DI.component.serializer.serialize_value(test)
+  end
+end

integration/apps/rails-seven/config/initializers/datadog.rb

@@ -1,6 +1,5 @@
 require 'datadog/statsd'
 require 'datadog'
-require 'datadog/appsec'
 
 Datadog.configure do |c|
   c.env = 'integration'
@@ -26,4 +25,8 @@
     # Reconfigure transport to write pprof to file
     c.profiling.exporter.transport = Datadog::DemoEnv.profiler_file_transport
   end
+
+  c.remote.enabled = true
+  c.dynamic_instrumentation.enabled = true
+  c.dynamic_instrumentation.internal.development = true
 end

integration/apps/rails-seven/config/routes.rb

@@ -10,6 +10,8 @@
   get 'basic/fibonacci', to: 'basic#fibonacci'
   get 'basic/boom', to: 'basic#boom'
 
+  get 'di/ar_serializer', to: 'di#ar_serializer'
+
   # Job test scenarios
   post 'jobs', to: 'jobs#create'
 end

integration/apps/rails-seven/spec/integration/di_spec.rb

@@ -0,0 +1,32 @@
+require 'spec_helper'
+require 'json'
+
+RSpec.describe 'Dynamic Instrumentation' do
+  include_context 'integration test'
+
+  describe 'ActiveRecord integration' do
+    subject { JSON.parse(get('di/ar_serializer').body) }
+
+    it 'is loaded' do
+      # If AR integration is loaded, this output will be the result of
+      # the custom serializer.
+      # If AR integration is not loaded, the output here will have a bunch of
+      # internal AR fields but not the attributes themselves.
+      expect(subject).to match(
+        {"type"=>"Test",
+         "entries"=>
+          [[{"type"=>"Symbol", "value"=>"attributes"},
+            {"type"=>"Hash",
+             "entries"=>
+              [[{"type"=>"String", "value"=>"id"}, {"type"=>"Integer", "value"=>String}],
+               [{"type"=>"String", "value"=>"version"}, {"type"=>"NilClass", "isNull"=>true}],
+               [{"type"=>"String", "value"=>"data"}, {"type"=>"NilClass", "isNull"=>true}],
+               [{"type"=>"String", "value"=>"created_at"},
+                {"type"=>"ActiveSupport::TimeWithZone", "value"=>String}],
+               [{"type"=>"String", "value"=>"updated_at"},
+                {"type"=>"ActiveSupport::TimeWithZone", "value"=>String}]]}],
+           [{"type"=>"Symbol", "value"=>"new_record"}, {"type"=>"FalseClass", "value"=>"false"}]]}
+      )
+    end
+  end
+end

lib/datadog/di.rb

@@ -18,21 +18,6 @@
 require_relative 'di/transport'
 require_relative 'di/utils'
 
-if defined?(ActiveRecord::Base)
-  # The third-party library integrations need to be loaded after the
-  # third-party libraries are loaded. Tracing and appsec use Railtie
-  # to delay integrations until all of the application's dependencies
-  # are loaded, when running under Rails. We should do the same here in
-  # principle, however DI currently only has an ActiveRecord integration
-  # and AR should be loaded before any application code is loaded, being
-  # part of Rails, therefore for now we should be OK to just require the
-  # AR integration from here.
-  #
-  # TODO this require might need to be delayed via Rails post-initialization
-  # logic?
-  require_relative 'di/contrib/active_record'
-end
-
 module Datadog
   # Namespace for Datadog dynamic instrumentation.
   #
@@ -75,3 +60,7 @@ def component
   # for line probes to work) activate tracking in an initializer.
   Datadog::DI.activate_tracking
 end
+
+require_relative 'di/contrib'
+
+Datadog::DI::Contrib.load_now_or_later

lib/datadog/di/contrib.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+require_relative '../core/contrib/rails/utils'
+
+module Datadog
+  module DI
+    module Contrib
+      module_function def load_now_or_later
+        if Datadog::Core::Contrib::Rails::Utils.railtie_supported?
+          require_relative 'contrib/railtie'
+        else
+          load_now
+        end
+      end
+
+      module_function def load_now
+        if defined?(ActiveRecord::Base)
+          require_relative 'contrib/active_record'
+        end
+      end
+    end
+  end
+end

lib/datadog/di/contrib/railtie.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module Datadog
+  module DI
+    module Contrib
+      # Railtie class initializes dynamic instrumentation contrib code
+      # in Rails environments.
+      class Railtie < Rails::Railtie
+        initializer 'datadog.dynamic_instrumentation.initialize' do |app|
+          Contrib.load_now
+        end
+      end
+    end
+  end
+end

sig/datadog/di/contrib.rbs

@@ -0,0 +1,9 @@
+module Datadog
+  module DI
+    module Contrib
+      def self?.load_now_or_later: () -> void
+
+      def self?.load_now: () -> void
+    end
+  end
+end

sig/datadog/di/contrib/railtie.rbs

@@ -0,0 +1,8 @@
+module Datadog
+  module DI
+    module Contrib
+      class Railtie < Rails::Railtie
+      end
+    end
+  end
+end