Add standalone Rails ActiveJob integration

docs/GettingStarted.md

@@ -30,6 +30,7 @@ To contribute, check out the [contribution guidelines][contribution docs] and [d
      - [Action View](#action-view)
      - [Active Model Serializers](#active-model-serializers)
      - [Action Pack](#action-pack)
+     - [Active Job](#active-job)
      - [Active Record](#active-record)
      - [Active Support](#active-support)
      - [AWS](#aws)
@@ -391,6 +392,7 @@ For a list of available integrations, and their configuration options, please re
 | Action View              | `action_view`              | `>= 3.0`                 | `>= 3.0`                  | *[Link](#action-view)*              | *[Link](https://github.com/rails/rails/tree/master/actionview)*                |
 | Active Model Serializers | `active_model_serializers` | `>= 0.9`                 | `>= 0.9`                  | *[Link](#active-model-serializers)* | *[Link](https://github.com/rails-api/active_model_serializers)*                |
 | Action Pack              | `action_pack`              | `>= 3.0`                 | `>= 3.0`                  | *[Link](#action-pack)*              | *[Link](https://github.com/rails/rails/tree/master/actionpack)*                |
+| Active Job               | `active_job`               | `>= 4.2`                 | `>= 4.2`                  | *[Link](#active-job)*               | *[Link](https://github.com/rails/rails/tree/master/activejob)*             |
 | Active Record            | `active_record`            | `>= 3.0`                 | `>= 3.0`                  | *[Link](#active-record)*            | *[Link](https://github.com/rails/rails/tree/master/activerecord)*              |
 | Active Support           | `active_support`           | `>= 3.0`                 | `>= 3.0`                  | *[Link](#active-support)*           | *[Link](https://github.com/rails/rails/tree/master/activesupport)*             |
 | AWS                      | `aws`                      | `>= 2.0`                 | `>= 2.0`                  | *[Link](#aws)*                      | *[Link](https://github.com/aws/aws-sdk-ruby)*                                  |
@@ -510,6 +512,27 @@ Where `options` is an optional `Hash` that accepts the following parameters:
 | ---| --- | --- |
 | `service_name` | Service name used for rendering instrumentation. | `action_pack` |
 
+### Active Job
+
+Most of the time, Active Job is set up as part of Rails, but it can be activated separately:
+
+```ruby
+require 'activejob'
+require 'ddtrace'
+
+Datadog.configure do |c|
+  c.use :active_job, options
+end
+
+ExampleJob.perform_later
+```
+
+Where `options` is an optional `Hash` that accepts the following parameters:
+
+| Key | Description | Default |
+| --- | ----------- | ------- |
+| `service_name` | Service name used for `active_job` instrumentation | `'active_job'` |
+
 ### Active Record
 
 Most of the time, Active Record is set up as part of a web framework (Rails, Sinatra...) however, it can be set up alone:

lib/datadog/contrib.rb

@@ -29,6 +29,7 @@ module Contrib
 require 'ddtrace/contrib/action_pack/integration'
 require 'ddtrace/contrib/action_view/integration'
 require 'ddtrace/contrib/active_model_serializers/integration'
+require 'ddtrace/contrib/active_job/integration'
 require 'ddtrace/contrib/active_record/integration'
 require 'ddtrace/contrib/active_support/integration'
 require 'ddtrace/contrib/aws/integration'

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

@@ -0,0 +1,32 @@
+# typed: false
+require 'ddtrace/contrib/configuration/settings'
+require 'ddtrace/contrib/active_job/ext'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      module Configuration
+        # Custom settings for the DelayedJob integration
+        class Settings < Contrib::Configuration::Settings
+          option :enabled do |o|
+            o.default { env_to_bool(Ext::ENV_ENABLED, true) }
+            o.lazy
+          end
+
+          option :analytics_enabled do |o|
+            o.default { env_to_bool([Ext::ENV_ANALYTICS_ENABLED, Ext::ENV_ANALYTICS_ENABLED_OLD], false) }
+            o.lazy
+          end
+
+          option :analytics_sample_rate do |o|
+            o.default { env_to_float([Ext::ENV_ANALYTICS_SAMPLE_RATE, Ext::ENV_ANALYTICS_SAMPLE_RATE_OLD], 1.0) }
+            o.lazy
+          end
+
+          option :service_name, default: Ext::SERVICE_NAME
+          option :error_handler, default: Datadog::Tracer::DEFAULT_ON_ERROR
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/active_job/event.rb

@@ -0,0 +1,31 @@
+# typed: true
+require 'ddtrace/contrib/active_support/notifications/event'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      # Defines basic behaviors for an ActiveJob event.
+      module Event
+        def self.included(base)
+          base.include(ActiveSupport::Notifications::Event)
+          base.extend(ClassMethods)
+        end
+
+        # Class methods for ActiveJob events.
+        module ClassMethods
+          def span_options
+            { service: configuration[:service_name] }
+          end
+
+          def tracer
+            -> { configuration[:tracer] }
+          end
+
+          def configuration
+            Datadog.configuration[:active_job]
+          end
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/active_job/events.rb

@@ -0,0 +1,31 @@
+# typed: false
+require 'ddtrace/contrib/active_job/events/enqueue'
+require 'ddtrace/contrib/active_job/events/perform'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      # Defines collection of instrumented ActiveJob events
+      module Events
+        ALL = [
+          Events::Enqueue,
+          Events::Perform,
+        ].freeze
+
+        module_function
+
+        def all
+          self::ALL
+        end
+
+        def subscriptions
+          all.collect(&:subscriptions).collect(&:to_a).flatten
+        end
+
+        def subscribe!
+          all.each(&:subscribe!)
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/active_job/events/enqueue.rb

@@ -0,0 +1,55 @@
+# typed: false
+require 'ddtrace/ext/integration'
+require 'ddtrace/contrib/analytics'
+require 'ddtrace/contrib/active_job/ext'
+require 'ddtrace/contrib/active_job/event'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      module Events
+        # Defines instrumentation for enqueue.active_job event
+        module Enqueue
+          include ActiveJob::Event
+
+          EVENT_NAME = 'enqueue.active_job'.freeze
+
+          module_function
+
+          def event_name
+            self::EVENT_NAME
+          end
+
+          def span_name
+            Ext::SPAN_ENQUEUE
+          end
+
+          def process(span, event, _id, payload)
+            span.name = span_name
+            span.service = configuration[:service_name]
+            span.resource = payload[:job].class.name
+
+            adapter_name = if payload[:adapter].is_a?(Class)
+                             payload[:adapter].name
+                           else
+                             payload[:adapter].class.name
+                           end
+            span.set_tag(Ext::TAG_ADAPTER, adapter_name)
+
+            # Set analytics sample rate
+            if Contrib::Analytics.enabled?(configuration[:analytics_enabled])
+              Contrib::Analytics.set_sample_rate(span, configuration[:analytics_sample_rate])
+            end
+
+            span.set_tag(Ext::TAG_JOB_ID, payload[:job].job_id)
+            span.set_tag(Ext::TAG_JOB_QUEUE, payload[:job].queue_name)
+
+            span.set_tag(Ext::TAG_JOB_PRIORITY, payload[:job].priority) if payload[:job].respond_to?(:priority)
+          rescue StandardError => e
+            Datadog.logger.debug(e.message)
+          end
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/active_job/events/perform.rb

@@ -0,0 +1,55 @@
+# typed: false
+require 'ddtrace/ext/integration'
+require 'ddtrace/contrib/analytics'
+require 'ddtrace/contrib/active_job/ext'
+require 'ddtrace/contrib/active_job/event'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      module Events
+        # Defines instrumentation for perform.active_job event
+        module Perform
+          include ActiveJob::Event
+
+          EVENT_NAME = 'perform.active_job'.freeze
+
+          module_function
+
+          def event_name
+            self::EVENT_NAME
+          end
+
+          def span_name
+            Ext::SPAN_PERFORM
+          end
+
+          def process(span, event, _id, payload)
+            span.name = span_name
+            span.service = configuration[:service_name]
+            span.resource = payload[:job].class.name
+
+            adapter_name = if payload[:adapter].is_a?(Class)
+                             payload[:adapter].name
+                           else
+                             payload[:adapter].class.name
+                           end
+            span.set_tag(Ext::TAG_ADAPTER, adapter_name)
+
+            # Set analytics sample rate
+            if Contrib::Analytics.enabled?(configuration[:analytics_enabled])
+              Contrib::Analytics.set_sample_rate(span, configuration[:analytics_sample_rate])
+            end
+
+            span.set_tag(Ext::TAG_JOB_ID, payload[:job].job_id)
+            span.set_tag(Ext::TAG_JOB_QUEUE, payload[:job].queue_name)
+
+            span.set_tag(Ext::TAG_JOB_PRIORITY, payload[:job].priority) if payload[:job].respond_to?(:priority)
+          rescue StandardError => e
+            Datadog.logger.debug(e.message)
+          end
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/active_job/ext.rb

@@ -0,0 +1,25 @@
+# typed: true
+module Datadog
+  module Contrib
+    module ActiveJob
+      module Ext
+        APP = 'active_job'.freeze
+        SERVICE_NAME = 'active_job'.freeze
+
+        ENV_ENABLED = 'DD_TRACE_ACTIVE_JOB_ENABLED'.freeze
+        ENV_ANALYTICS_ENABLED = 'DD_TRACE_ACTIVE_JOB_ANALYTICS_ENABLED'.freeze
+        ENV_ANALYTICS_ENABLED_OLD = 'DD_ACTIVE_JOB_ANALYTICS_ENABLED'.freeze
+        ENV_ANALYTICS_SAMPLE_RATE = 'DD_TRACE_ACTIVE_JOB_ANALYTICS_SAMPLE_RATE'.freeze
+        ENV_ANALYTICS_SAMPLE_RATE_OLD = 'DD_ACTIVE_JOB_ANALYTICS_SAMPLE_RATE'.freeze
+
+        SPAN_PERFORM = 'active_job.perform'.freeze
+        SPAN_ENQUEUE = 'active_job.enqueue'.freeze
+
+        TAG_ADAPTER = 'active_job.adapter'.freeze
+        TAG_JOB_ID = 'active_job.job.id'.freeze
+        TAG_JOB_QUEUE = 'active_job.job.queue'.freeze
+        TAG_JOB_PRIORITY = 'active_job.job.priority'.freeze
+      end
+    end
+  end
+end

lib/ddtrace/contrib/active_job/integration.rb

@@ -0,0 +1,46 @@
+# typed: false
+require 'ddtrace/contrib/integration'
+require 'ddtrace/contrib/active_job/configuration/settings'
+require 'ddtrace/contrib/active_job/patcher'
+require 'ddtrace/contrib/rails/utils'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      # Describes the ActiveJob integration
+      class Integration
+        include Contrib::Integration
+
+        MINIMUM_VERSION = Gem::Version.new('4.2')
+
+        register_as :active_job, auto_patch: false
+
+        def self.version
+          Gem.loaded_specs['activejob'] && Gem.loaded_specs['activejob'].version
+        end
+
+        def self.loaded?
+          !defined?(::ActiveJob).nil?
+        end
+
+        def self.compatible?
+          super && version >= MINIMUM_VERSION
+        end
+
+        # enabled by rails integration so should only auto instrument
+        # if detected that it is being used without rails
+        def auto_instrument?
+          !Datadog::Contrib::Rails::Utils.railtie_supported?
+        end
+
+        def default_configuration
+          Configuration::Settings.new
+        end
+
+        def patcher
+          ActiveJob::Patcher
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/active_job/patcher.rb

@@ -0,0 +1,25 @@
+# typed: true
+require 'ddtrace/contrib/patcher'
+require 'ddtrace/contrib/active_job/ext'
+require 'ddtrace/contrib/active_job/events'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      # Patcher enables patching of 'active_job' module.
+      module Patcher
+        include Contrib::Patcher
+
+        module_function
+
+        def target_version
+          Integration.version
+        end
+
+        def patch
+          Events.subscribe!
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/rails/framework.rb

@@ -48,6 +48,7 @@ def self.setup
             activate_active_support!(datadog_config, rails_config)
             activate_action_pack!(datadog_config, rails_config)
             activate_action_view!(datadog_config, rails_config)
+            activate_active_job!(datadog_config, rails_config)
             activate_active_record!(datadog_config, rails_config)
             activate_lograge!(datadog_config, rails_config)
             activate_semantic_logger!(datadog_config, rails_config)
@@ -115,6 +116,15 @@ def self.activate_action_view!(datadog_config, rails_config)
           )
         end
 
+        def self.activate_active_job!(datadog_config, rails_config)
+          return unless defined?(::ActiveJob)
+
+          datadog_config.use(
+            :active_job,
+            service_name: "#{rails_config[:service_name]}-#{Contrib::ActiveJob::Ext::SERVICE_NAME}"
+          )
+        end
+
         def self.activate_active_record!(datadog_config, rails_config)
           return unless defined?(::ActiveRecord)