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 +1,54 @@
+# typed: true
+require 'ddtrace/contrib/active_support/notifications/event'
+require 'ddtrace/contrib/active_job/ext'
+
+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
+
+          def set_common_tags(span, payload)
+            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)
+
+            job = payload[:job]
+            span.set_tag(Ext::TAG_JOB_ID, job.job_id)
+            span.set_tag(Ext::TAG_JOB_QUEUE, job.queue_name)
+            span.set_tag(Ext::TAG_JOB_PRIORITY, job.priority) if job.respond_to?(:priority)
+            span.set_tag(Ext::TAG_JOB_EXECUTIONS, job.executions) if job.respond_to?(:executions)
+
+            job_scheduled_at = if job.respond_to?(:scheduled_at)
+                                 job.scheduled_at
+                               elsif job.respond_to?(:enqueued_at)
+                                 job.enqueued_at
+                               end
+            span.set_tag(Ext::TAG_JOB_SCHEDULED_AT, Time.at(job_scheduled_at)) if job_scheduled_at
+          end
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/active_job/events.rb

@@ -0,0 +1,39 @@
+# typed: false
+require 'ddtrace/contrib/active_job/events/discard'
+require 'ddtrace/contrib/active_job/events/enqueue'
+require 'ddtrace/contrib/active_job/events/enqueue_at'
+require 'ddtrace/contrib/active_job/events/enqueue_retry'
+require 'ddtrace/contrib/active_job/events/perform'
+require 'ddtrace/contrib/active_job/events/retry_stopped'
+
+module Datadog
+  module Contrib
+    module ActiveJob
+      # Defines collection of instrumented ActiveJob events
+      module Events
+        ALL = [
+          Events::Discard,
+          Events::Enqueue,
+          Events::EnqueueAt,
+          Events::EnqueueRetry,
+          Events::Perform,
+          Events::RetryStopped,
+        ].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/discard.rb

@@ -0,0 +1,46 @@
+# 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 Discard
+          include ActiveJob::Event
+
+          EVENT_NAME = 'discard.active_job'.freeze
+
+          module_function
+
+          def event_name
+            self::EVENT_NAME
+          end
+
+          def span_name
+            Ext::SPAN_DISCARD
+          end
+
+          def process(span, event, _id, payload)
+            span.name = span_name
+            span.service = configuration[:service_name]
+            span.resource = payload[:job].class.name
+
+            # Set analytics sample rate
+            if Contrib::Analytics.enabled?(configuration[:analytics_enabled])
+              Contrib::Analytics.set_sample_rate(span, configuration[:analytics_sample_rate])
+            end
+
+            set_common_tags(span, payload)
+            span.set_tag(Ext::TAG_JOB_ERROR, payload[:error])
+          rescue StandardError => e
+            Datadog.logger.debug(e.message)
+          end
+        end
+      end
+    end
+  end
+end

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

@@ -0,0 +1,45 @@
+# 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
+
+            # Set analytics sample rate
+            if Contrib::Analytics.enabled?(configuration[:analytics_enabled])
+              Contrib::Analytics.set_sample_rate(span, configuration[:analytics_sample_rate])
+            end
+
+            set_common_tags(span, payload)
+          rescue StandardError => e
+            Datadog.logger.debug(e.message)
+          end
+        end
+      end
+    end
+  end
+end

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

@@ -0,0 +1,45 @@
+# 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 EnqueueAt
+          include ActiveJob::Event
+
+          EVENT_NAME = 'enqueue_at.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
+
+            # Set analytics sample rate
+            if Contrib::Analytics.enabled?(configuration[:analytics_enabled])
+              Contrib::Analytics.set_sample_rate(span, configuration[:analytics_sample_rate])
+            end
+
+            set_common_tags(span, payload)
+          rescue StandardError => e
+            Datadog.logger.debug(e.message)
+          end
+        end
+      end
+    end
+  end
+end

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

@@ -0,0 +1,47 @@
+# 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 EnqueueRetry
+          include ActiveJob::Event
+
+          EVENT_NAME = 'enqueue_retry.active_job'.freeze
+
+          module_function
+
+          def event_name
+            self::EVENT_NAME
+          end
+
+          def span_name
+            Ext::SPAN_ENQUEUE_RETRY
+          end
+
+          def process(span, event, _id, payload)
+            span.name = span_name
+            span.service = configuration[:service_name]
+            span.resource = payload[:job].class.name
+
+            # Set analytics sample rate
+            if Contrib::Analytics.enabled?(configuration[:analytics_enabled])
+              Contrib::Analytics.set_sample_rate(span, configuration[:analytics_sample_rate])
+            end
+
+            set_common_tags(span, payload)
+            span.set_tag(Ext::TAG_JOB_ERROR, payload[:error])
+            span.set_tag(Ext::TAG_JOB_RETRY_WAIT, payload[:wait])
+          rescue StandardError => e
+            Datadog.logger.debug(e.message)
+          end
+        end
+      end
+    end
+  end
+end