Add a copy of the upstream delayed_job otel instrumentation

This is commit is there just to comply with the Apache2 License,
so that modifications will be later visible/traceable.

Co-Authored-By: MarcWoern <[email protected]>

Author: FloThinksPi

lib/delayed_job/opentelemetry/instrumentation.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+# Copyright The OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+# OpenTelemetry is an open source observability framework, providing a
+# general-purpose API, SDK, and related tools required for the instrumentation
+# of cloud-native software, frameworks, and libraries.
+#
+# The OpenTelemetry module provides global accessors for telemetry objects.
+# See the documentation for the `opentelemetry-api` gem for details.
+module OpenTelemetry
+  # "Instrumentation" are specified by
+  # https://github.com/open-telemetry/opentelemetry-specification/blob/784635d01d8690c8f5fcd1f55bdbc8a13cf2f4f2/specification/glossary.md#instrumentation-library
+  #
+  # Instrumentation should be able to handle the case when the library is not installed on a user's system.
+  module Instrumentation
+  end
+end
+
+require_relative 'instrumentation/delayed_job'

lib/delayed_job/opentelemetry/instrumentation/delayed_job.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+# Copyright The OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+require 'opentelemetry'
+require 'opentelemetry-instrumentation-base'
+
+module OpenTelemetry
+  module Instrumentation
+    # Contains the OpenTelemetry instrumentation for the DelayedJob gem
+    module DelayedJob
+    end
+  end
+end
+
+require_relative 'delayed_job/instrumentation'
+require_relative 'delayed_job/version'

lib/delayed_job/opentelemetry/instrumentation/delayed_job/instrumentation.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+# Copyright The OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+module OpenTelemetry
+  module Instrumentation
+    module DelayedJob
+      # Instrumentation class that detects and installs the DelayedJob instrumentation
+      class Instrumentation < OpenTelemetry::Instrumentation::Base
+        MINIMUM_VERSION = Gem::Version.new('4.1')
+
+        install do |_config|
+          require_dependencies
+          register_tracer_plugin
+        end
+
+        present do
+          !defined?(::Delayed).nil?
+        end
+
+        compatible do
+          # Version is hardcoded in the gemspec
+          # https://github.com/collectiveidea/delayed_job/blob/master/delayed_job.gemspec#L16
+          gem_version = Gem.loaded_specs['delayed_job']&.version
+          gem_version && gem_version >= MINIMUM_VERSION
+        end
+
+        private
+
+        def require_dependencies
+          require_relative 'plugins/tracer_plugin'
+        end
+
+        def register_tracer_plugin
+          ::Delayed::Worker.plugins << Plugins::TracerPlugin
+        end
+      end
+    end
+  end
+end

lib/delayed_job/opentelemetry/instrumentation/delayed_job/plugins/tracer_plugin.rb

@@ -0,0 +1,95 @@
+# frozen_string_literal: true
+
+# Copyright The OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+require 'delayed/plugin'
+
+module OpenTelemetry
+  module Instrumentation
+    module DelayedJob
+      module Plugins
+        # Delayed Job plugin that instruments invoke_job and other hooks
+        class TracerPlugin < Delayed::Plugin
+          class << self
+            def instrument_enqueue(job, &block)
+              return yield(job) unless enabled?
+
+              attributes = build_attributes(job)
+              attributes['messaging.operation'] = 'publish'
+              attributes.compact!
+
+              tracer.in_span("#{job_queue(job)} publish", attributes: attributes, kind: :producer) do |span|
+                yield job
+                span.set_attribute('messaging.message_id', job.id.to_s)
+                add_events(span, job)
+              end
+            end
+
+            def instrument_invoke(job, &block)
+              return yield(job) unless enabled?
+
+              attributes = build_attributes(job)
+              attributes['messaging.delayed_job.attempts'] = job.attempts if job.attempts
+              attributes['messaging.delayed_job.locked_by'] = job.locked_by if job.locked_by
+              attributes['messaging.operation'] = 'process'
+              attributes['messaging.message_id'] = job.id.to_s
+              attributes.compact!
+
+              tracer.in_span("#{job_queue(job)} process", attributes: attributes, kind: :consumer) do |span|
+                add_events(span, job)
+                yield job
+              end
+            end
+
+            protected
+
+            def build_attributes(job)
+              {
+                'messaging.system' => 'delayed_job',
+                'messaging.destination' => job_queue(job),
+                'messaging.destination_kind' => 'queue',
+                'messaging.delayed_job.name' => job_name(job),
+                'messaging.delayed_job.priority' => job.priority
+              }
+            end
+
+            def add_events(span, job)
+              span.add_event('run_at', timestamp: job.run_at) if job.run_at
+              span.add_event('locked_at', timestamp: job.locked_at) if job.locked_at
+            end
+
+            def enabled?
+              DelayedJob::Instrumentation.instance.enabled?
+            end
+
+            def tracer
+              DelayedJob::Instrumentation.instance.tracer
+            end
+
+            def job_name(job)
+              # If Delayed Job is used via ActiveJob then get the job name from the payload
+              if job.payload_object.respond_to?(:job_data)
+                job.payload_object.job_data['job_class']
+              else
+                job.name
+              end
+            end
+
+            def job_queue(job)
+              job.queue || 'default'
+            end
+          end
+
+          callbacks do |lifecycle|
+            # rubocop:disable Performance/MethodObjectAsBlock
+            lifecycle.around(:enqueue, &method(:instrument_enqueue))
+            lifecycle.around(:invoke_job, &method(:instrument_invoke))
+            # rubocop:enable Performance/MethodObjectAsBlock
+          end
+        end
+      end
+    end
+  end
+end

lib/delayed_job/opentelemetry/instrumentation/delayed_job/version.rb

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+# frozen_string_literal: true
+
+# Copyright The OpenTelemetry Authors
+#
+# SPDX-License-Identifier: Apache-2.0
+
+module OpenTelemetry
+  module Instrumentation
+    module DelayedJob
+      VERSION = '0.22.1'
+    end
+  end
+end