Refactored: Racecar to use Datadog::Contrib::Integration. (#548)

lib/ddtrace.rb

@@ -60,7 +60,7 @@ def configure(target = configuration, opts = {})
 require 'ddtrace/contrib/integration'
 require 'ddtrace/contrib/mongodb/patcher'
 require 'ddtrace/contrib/mysql2/patcher'
-require 'ddtrace/contrib/racecar/patcher'
+require 'ddtrace/contrib/racecar/integration'
 require 'ddtrace/contrib/rack/integration'
 require 'ddtrace/contrib/rails/integration'
 require 'ddtrace/contrib/rake/patcher'

lib/ddtrace/contrib/racecar/configuration/settings.rb

@@ -0,0 +1,23 @@
+require 'ddtrace/contrib/configuration/settings'
+require 'ddtrace/contrib/racecar/ext'
+
+module Datadog
+  module Contrib
+    module Racecar
+      module Configuration
+        # Custom settings for the Rack integration
+        class Settings < Contrib::Configuration::Settings
+          option :service_name, default: Ext::SERVICE_NAME
+          option :tracer, default: Datadog.tracer do |value|
+            (value || Datadog.tracer).tap do |v|
+              # Make sure to update tracers of all subscriptions
+              Events.subscriptions.each do |subscription|
+                subscription.tracer = v
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/racecar/event.rb

@@ -1,4 +1,5 @@
 require 'ddtrace/contrib/active_support/notifications/event'
+require 'ddtrace/contrib/racecar/ext'
 
 module Datadog
   module Contrib
@@ -35,12 +36,12 @@ def process(span, event, _id, payload)
             span.service = configuration[:service_name]
             span.resource = payload[:consumer_class]
 
-            span.set_tag('kafka.topic', payload[:topic])
-            span.set_tag('kafka.consumer', payload[:consumer_class])
-            span.set_tag('kafka.partition', payload[:partition])
-            span.set_tag('kafka.offset', payload[:offset]) if payload.key?(:offset)
-            span.set_tag('kafka.first_offset', payload[:first_offset]) if payload.key?(:first_offset)
-            span.set_tag('kafka.message_count', payload[:message_count]) if payload.key?(:message_count)
+            span.set_tag(Ext::TAG_TOPIC, payload[:topic])
+            span.set_tag(Ext::TAG_CONSUMER, payload[:consumer_class])
+            span.set_tag(Ext::TAG_PARTITION, payload[:partition])
+            span.set_tag(Ext::TAG_OFFSET, payload[:offset]) if payload.key?(:offset)
+            span.set_tag(Ext::TAG_FIRST_OFFSET, payload[:first_offset]) if payload.key?(:first_offset)
+            span.set_tag(Ext::TAG_MESSAGE_COUNT, payload[:message_count]) if payload.key?(:message_count)
             span.set_error(payload[:exception_object]) if payload[:exception_object]
           end
 

lib/ddtrace/contrib/racecar/events/batch.rb

@@ -1,3 +1,4 @@
+require 'ddtrace/contrib/racecar/ext'
 require 'ddtrace/contrib/racecar/event'
 
 module Datadog
@@ -9,7 +10,6 @@ module Batch
           include Racecar::Event
 
           EVENT_NAME = 'process_batch.racecar'.freeze
-          SPAN_NAME = 'racecar.batch'.freeze
 
           module_function
 
@@ -18,7 +18,7 @@ def event_name
           end
 
           def span_name
-            self::SPAN_NAME
+            Ext::SPAN_BATCH
           end
         end
       end

lib/ddtrace/contrib/racecar/events/message.rb

@@ -1,3 +1,4 @@
+require 'ddtrace/contrib/racecar/ext'
 require 'ddtrace/contrib/racecar/event'
 
 module Datadog
@@ -9,7 +10,6 @@ module Message
           include Racecar::Event
 
           EVENT_NAME = 'process_message.racecar'.freeze
-          SPAN_NAME = 'racecar.message'.freeze
 
           module_function
 
@@ -18,7 +18,7 @@ def event_name
           end
 
           def span_name
-            self::SPAN_NAME
+            Ext::SPAN_MESSAGE
           end
         end
       end

lib/ddtrace/contrib/racecar/ext.rb

@@ -0,0 +1,21 @@
+module Datadog
+  module Contrib
+    module Racecar
+      # Racecar integration constants
+      module Ext
+        APP = 'racecar'.freeze
+        SERVICE_NAME = 'racecar'.freeze
+
+        SPAN_BATCH = 'racecar.batch'.freeze
+        SPAN_MESSAGE = 'racecar.message'.freeze
+
+        TAG_CONSUMER = 'kafka.consumer'.freeze
+        TAG_FIRST_OFFSET = 'kafka.first_offset'.freeze
+        TAG_MESSAGE_COUNT = 'kafka.message_count'.freeze
+        TAG_OFFSET = 'kafka.offset'.freeze
+        TAG_PARTITION = 'kafka.partition'.freeze
+        TAG_TOPIC = 'kafka.topic'.freeze
+      end
+    end
+  end
+end

lib/ddtrace/contrib/racecar/integration.rb

@@ -0,0 +1,36 @@
+require 'ddtrace/contrib/integration'
+require 'ddtrace/contrib/racecar/configuration/settings'
+require 'ddtrace/contrib/racecar/patcher'
+
+module Datadog
+  module Contrib
+    module Racecar
+      # Description of Racecar integration
+      class Integration
+        include Contrib::Integration
+
+        register_as :racecar, auto_patch: false
+
+        def self.version
+          Gem.loaded_specs['racecar'] && Gem.loaded_specs['racecar'].version
+        end
+
+        def self.present?
+          super && defined?(::Racecar)
+        end
+
+        def self.compatible?
+          super && defined?(::ActiveSupport::Notifications)
+        end
+
+        def default_configuration
+          Configuration::Settings.new
+        end
+
+        def patcher
+          Patcher
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/racecar/patcher.rb

@@ -1,54 +1,37 @@
+require 'ddtrace/contrib/patcher'
 require 'ddtrace/ext/app_types'
+require 'ddtrace/contrib/racecar/ext'
 require 'ddtrace/contrib/racecar/events'
 
 module Datadog
   module Contrib
     module Racecar
-      # Provides instrumentation for `racecar` through ActiveSupport instrumentation signals
+      # Patcher enables patching of 'racecar' module.
       module Patcher
-        include Base
+        include Contrib::Patcher
 
-        register_as :racecar
-        option :service_name, default: 'racecar'
-        option :tracer, default: Datadog.tracer do |value|
-          (value || Datadog.tracer).tap do |v|
-            # Make sure to update tracers of all subscriptions
-            Events.subscriptions.each do |subscription|
-              subscription.tracer = v
-            end
-          end
-        end
-
-        class << self
-          def patch
-            return patched? if patched? || !compatible?
-
-            # Subscribe to Racecar events
-            Events.subscribe!
-
-            # Set service info
-            configuration[:tracer].set_service_info(
-              configuration[:service_name],
-              'racecar',
-              Ext::AppTypes::WORKER
-            )
-
-            @patched = true
-          end
-
-          def patched?
-            return @patched if defined?(@patched)
-            @patched = false
-          end
-
-          private
+        module_function
 
-          def configuration
-            Datadog.configuration[:racecar]
-          end
+        def patched?
+          done?(:racecar)
+        end
 
-          def compatible?
-            defined?(::Racecar) && defined?(::ActiveSupport::Notifications)
+        def patch
+          do_once(:racecar) do
+            begin
+              # Subscribe to Racecar events
+              Events.subscribe!
+
+              # Set service info
+              configuration = Datadog.configuration[:racecar]
+              configuration[:tracer].set_service_info(
+                configuration[:service_name],
+                Ext::APP,
+                Datadog::Ext::AppTypes::WORKER
+              )
+            rescue StandardError => e
+              Datadog::Tracer.log.error("Unable to apply Racecar integration: #{e}")
+            end
           end
         end
       end

spec/ddtrace/contrib/racecar/patcher_spec.rb

@@ -32,7 +32,7 @@ def all_spans
     end
 
     let(:racecar_span) do
-      all_spans.select { |s| s.name == Datadog::Contrib::Racecar::Events::Message::SPAN_NAME }.first
+      all_spans.select { |s| s.name == Datadog::Contrib::Racecar::Ext::SPAN_MESSAGE }.first
     end
 
     context 'that doesn\'t raise an error' do
@@ -100,7 +100,7 @@ def all_spans
     end
 
     let(:racecar_span) do
-      all_spans.select { |s| s.name == Datadog::Contrib::Racecar::Events::Batch::SPAN_NAME }.first
+      all_spans.select { |s| s.name == Datadog::Contrib::Racecar::Ext::SPAN_BATCH }.first
     end
 
     context 'that doesn\'t raise an error' do