Merge pull request #700 from DataDog/refactor/grape_replace_pin_with_…

…config

Deprecate Grape pin in favor of configuration API

docs/GettingStarted.md

@@ -659,6 +659,7 @@ Where `options` is an optional `Hash` that accepts the following parameters:
 
 | Key | Description | Default |
 | --- | ----------- | ------- |
+| `enabled` | Defines whether Grape should be traced. Useful for temporarily disabling tracing. `true` or `false` | `true` |
 | `service_name` | Service name used for `grape` instrumentation | `'grape'` |
 | `tracer` | `Datadog::Tracer` used to perform instrumentation. Usually you don't need to set this. | `Datadog.tracer` |
 

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

@@ -8,6 +8,7 @@ module Grape
       module Configuration
         # Custom settings for the Grape integration
         class Settings < Contrib::Configuration::Settings
+          option :enabled, default: true
           option :service_name, default: Ext::SERVICE_NAME
         end
       end

lib/ddtrace/contrib/grape/endpoint.rb

@@ -12,158 +12,167 @@ module Endpoint
         KEY_RUN = 'datadog_grape_endpoint_run'.freeze
         KEY_RENDER = 'datadog_grape_endpoint_render'.freeze
 
-        def self.subscribe
-          # subscribe when a Grape endpoint is hit
-          ::ActiveSupport::Notifications.subscribe('endpoint_run.grape.start_process') do |*args|
-            endpoint_start_process(*args)
-          end
-          ::ActiveSupport::Notifications.subscribe('endpoint_run.grape') do |*args|
-            endpoint_run(*args)
-          end
-          ::ActiveSupport::Notifications.subscribe('endpoint_render.grape.start_render') do |*args|
-            endpoint_start_render(*args)
-          end
-          ::ActiveSupport::Notifications.subscribe('endpoint_render.grape') do |*args|
-            endpoint_render(*args)
-          end
-          ::ActiveSupport::Notifications.subscribe('endpoint_run_filters.grape') do |*args|
-            endpoint_run_filters(*args)
+        class << self
+          def subscribe
+            # subscribe when a Grape endpoint is hit
+            ::ActiveSupport::Notifications.subscribe('endpoint_run.grape.start_process') do |*args|
+              endpoint_start_process(*args)
+            end
+            ::ActiveSupport::Notifications.subscribe('endpoint_run.grape') do |*args|
+              endpoint_run(*args)
+            end
+            ::ActiveSupport::Notifications.subscribe('endpoint_render.grape.start_render') do |*args|
+              endpoint_start_render(*args)
+            end
+            ::ActiveSupport::Notifications.subscribe('endpoint_render.grape') do |*args|
+              endpoint_render(*args)
+            end
+            ::ActiveSupport::Notifications.subscribe('endpoint_run_filters.grape') do |*args|
+              endpoint_run_filters(*args)
+            end
           end
-        end
-
-        def self.endpoint_start_process(*)
-          return if Thread.current[KEY_RUN]
 
-          # retrieve the tracer from the PIN object
-          pin = Datadog::Pin.get_from(::Grape)
-          return unless pin && pin.enabled?
+          def endpoint_start_process(*)
+            return if Thread.current[KEY_RUN]
+            return unless enabled?
 
-          # store the beginning of a trace
-          tracer = pin.tracer
-          service = pin.service
-          type = Datadog::Ext::HTTP::TYPE
-          tracer.trace(Ext::SPAN_ENDPOINT_RUN, service: service, span_type: type)
+            # Store the beginning of a trace
+            tracer.trace(
+              Ext::SPAN_ENDPOINT_RUN,
+              service: service_name,
+              span_type: Datadog::Ext::HTTP::TYPE
+            )
 
-          Thread.current[KEY_RUN] = true
-        rescue StandardError => e
-          Datadog::Tracer.log.error(e.message)
-        end
+            Thread.current[KEY_RUN] = true
+          rescue StandardError => e
+            Datadog::Tracer.log.error(e.message)
+          end
 
-        def self.endpoint_run(name, start, finish, id, payload)
-          return unless Thread.current[KEY_RUN]
-          Thread.current[KEY_RUN] = false
-
-          # retrieve the tracer from the PIN object
-          pin = Datadog::Pin.get_from(::Grape)
-          return unless pin && pin.enabled?
-
-          tracer = pin.tracer
-          span = tracer.active_span
-          return unless span
-
-          begin
-            # collect endpoint details
-            api = payload[:endpoint].options[:for]
-            # If the API inherits from Grape::API in version >= 1.2.0
-            # then the API will be an instance and the name must be derived from the base.
-            # See https://github.com/ruby-grape/grape/issues/1825
-            api_view = if defined?(::Grape::API::Instance) && api <= ::Grape::API::Instance
-                         api.base.to_s
-                       else
-                         api.to_s
-                       end
-
-            path = payload[:endpoint].options[:path].join('/')
-            resource = "#{api_view}##{path}"
-            span.resource = resource
-
-            # set the request span resource if it's a `rack.request` span
-            request_span = payload[:env][Datadog::Contrib::Rack::Ext::RACK_ENV_REQUEST_SPAN]
-            if !request_span.nil? && request_span.name == Datadog::Contrib::Rack::Ext::SPAN_REQUEST
-              request_span.resource = resource
+          def endpoint_run(name, start, finish, id, payload)
+            return unless Thread.current[KEY_RUN]
+            Thread.current[KEY_RUN] = false
+
+            return unless enabled?
+
+            span = tracer.active_span
+            return unless span
+
+            begin
+              # collect endpoint details
+              api = payload[:endpoint].options[:for]
+              # If the API inherits from Grape::API in version >= 1.2.0
+              # then the API will be an instance and the name must be derived from the base.
+              # See https://github.com/ruby-grape/grape/issues/1825
+              api_view = if defined?(::Grape::API::Instance) && api <= ::Grape::API::Instance
+                           api.base.to_s
+                         else
+                           api.to_s
+                         end
+
+              path = payload[:endpoint].options[:path].join('/')
+              resource = "#{api_view}##{path}"
+              span.resource = resource
+
+              # set the request span resource if it's a `rack.request` span
+              request_span = payload[:env][Datadog::Contrib::Rack::Ext::RACK_ENV_REQUEST_SPAN]
+              if !request_span.nil? && request_span.name == Datadog::Contrib::Rack::Ext::SPAN_REQUEST
+                request_span.resource = resource
+              end
+
+              # catch thrown exceptions
+              span.set_error(payload[:exception_object]) unless payload[:exception_object].nil?
+
+              # override the current span with this notification values
+              span.set_tag(Ext::TAG_ROUTE_ENDPOINT, api_view) unless api_view.nil?
+              span.set_tag(Ext::TAG_ROUTE_PATH, path)
+            ensure
+              span.start_time = start
+              span.finish(finish)
             end
-
-            # catch thrown exceptions
-            span.set_error(payload[:exception_object]) unless payload[:exception_object].nil?
-
-            # override the current span with this notification values
-            span.set_tag(Ext::TAG_ROUTE_ENDPOINT, api_view) unless api_view.nil?
-            span.set_tag(Ext::TAG_ROUTE_PATH, path)
-          ensure
-            span.start_time = start
-            span.finish(finish)
+          rescue StandardError => e
+            Datadog::Tracer.log.error(e.message)
           end
-        rescue StandardError => e
-          Datadog::Tracer.log.error(e.message)
-        end
 
-        def self.endpoint_start_render(*)
-          return if Thread.current[KEY_RENDER]
+          def endpoint_start_render(*)
+            return if Thread.current[KEY_RENDER]
+            return unless enabled?
 
-          # retrieve the tracer from the PIN object
-          pin = Datadog::Pin.get_from(::Grape)
-          return unless pin && pin.enabled?
+            # Store the beginning of a trace
+            tracer.trace(
+              Ext::SPAN_ENDPOINT_RENDER,
+              service: service_name,
+              span_type: Datadog::Ext::HTTP::TYPE
+            )
 
-          # store the beginning of a trace
-          tracer = pin.tracer
-          service = pin.service
-          type = Datadog::Ext::HTTP::TYPE
-          tracer.trace(Ext::SPAN_ENDPOINT_RENDER, service: service, span_type: type)
+            Thread.current[KEY_RENDER] = true
+          rescue StandardError => e
+            Datadog::Tracer.log.error(e.message)
+          end
 
-          Thread.current[KEY_RENDER] = true
-        rescue StandardError => e
-          Datadog::Tracer.log.error(e.message)
-        end
+          def endpoint_render(name, start, finish, id, payload)
+            return unless Thread.current[KEY_RENDER]
+            Thread.current[KEY_RENDER] = false
 
-        def self.endpoint_render(name, start, finish, id, payload)
-          return unless Thread.current[KEY_RENDER]
-          Thread.current[KEY_RENDER] = false
+            return unless enabled?
 
-          # retrieve the tracer from the PIN object
-          pin = Datadog::Pin.get_from(::Grape)
-          return unless pin && pin.enabled?
+            span = tracer.active_span
+            return unless span
 
-          tracer = pin.tracer
-          span = tracer.active_span
-          return unless span
+            # catch thrown exceptions
+            begin
+              span.set_error(payload[:exception_object]) unless payload[:exception_object].nil?
+            ensure
+              span.start_time = start
+              span.finish(finish)
+            end
+          rescue StandardError => e
+            Datadog::Tracer.log.error(e.message)
+          end
 
-          # catch thrown exceptions
-          begin
-            span.set_error(payload[:exception_object]) unless payload[:exception_object].nil?
-          ensure
-            span.start_time = start
-            span.finish(finish)
+          def endpoint_run_filters(name, start, finish, id, payload)
+            return unless enabled?
+
+            # safe-guard to prevent submitting empty filters
+            zero_length = (finish - start).zero?
+            filters = payload[:filters]
+            type = payload[:type]
+            return if (!filters || filters.empty?) || !type || zero_length
+
+            span = tracer.trace(
+              Ext::SPAN_ENDPOINT_RUN_FILTERS,
+              service: service_name,
+              span_type: Datadog::Ext::HTTP::TYPE
+            )
+
+            begin
+              # catch thrown exceptions
+              span.set_error(payload[:exception_object]) unless payload[:exception_object].nil?
+              span.set_tag(Ext::TAG_FILTER_TYPE, type.to_s)
+            ensure
+              span.start_time = start
+              span.finish(finish)
+            end
+          rescue StandardError => e
+            Datadog::Tracer.log.error(e.message)
           end
-        rescue StandardError => e
-          Datadog::Tracer.log.error(e.message)
-        end
 
-        def self.endpoint_run_filters(name, start, finish, id, payload)
-          # retrieve the tracer from the PIN object
-          pin = Datadog::Pin.get_from(::Grape)
-          return unless pin && pin.enabled?
+          private
 
-          # safe-guard to prevent submitting empty filters
-          zero_length = (finish - start).zero?
-          filters = payload[:filters]
-          type = payload[:type]
-          return if (!filters || filters.empty?) || !type || zero_length
+          def tracer
+            datadog_configuration[:tracer]
+          end
 
-          tracer = pin.tracer
-          service = pin.service
-          type = Datadog::Ext::HTTP::TYPE
-          span = tracer.trace('grape.endpoint_run_filters', service: service, span_type: type)
+          def service_name
+            datadog_configuration[:service_name]
+          end
 
-          begin
-            # catch thrown exceptions
-            span.set_error(payload[:exception_object]) unless payload[:exception_object].nil?
-            span.set_tag(Ext::TAG_FILTER_TYPE, type.to_s)
-          ensure
-            span.start_time = start
-            span.finish(finish)
+          def enabled?
+            datadog_configuration[:enabled] == true
+          end
+
+          def datadog_configuration
+            Datadog.configuration[:grape]
           end
-        rescue StandardError => e
-          Datadog::Tracer.log.error(e.message)
         end
       end
     end

lib/ddtrace/contrib/grape/instrumentation.rb

@@ -0,0 +1,73 @@
+module Datadog
+  module Contrib
+    module Grape
+      # Instrumentation for Grape::Endpoint
+      module Instrumentation
+        def self.included(base)
+          if Gem::Version.new(RUBY_VERSION) < Gem::Version.new('2.0.0')
+            base.class_eval do
+              # Class methods
+              singleton_class.send(:include, ClassMethodsCompatibility)
+              singleton_class.send(:include, ClassMethods)
+
+              # Instance methods
+              include InstanceMethodsCompatibility
+              include InstanceMethods
+            end
+          else
+            base.singleton_class.send(:prepend, ClassMethods)
+            base.send(:prepend, InstanceMethods)
+          end
+        end
+
+        # Compatibility shim for Rubies not supporting `.prepend`
+        module ClassMethodsCompatibility
+          def self.included(base)
+            base.class_eval do
+              alias_method :generate_api_method_without_datadog, :generate_api_method
+              remove_method :generate_api_method
+            end
+          end
+
+          def generate_api_method(*args, &block)
+            generate_api_method_without_datadog(*args, &block)
+          end
+        end
+
+        # Compatibility shim for Rubies not supporting `.prepend`
+        module InstanceMethodsCompatibility
+          def self.included(base)
+            base.class_eval do
+              alias_method :run_without_datadog, :run
+              remove_method :run
+            end
+          end
+
+          def run(*args, &block)
+            run_without_datadog(*args, &block)
+          end
+        end
+
+        # ClassMethods - implementing instrumentation
+        module ClassMethods
+          def generate_api_method(*params, &block)
+            method_api = super
+
+            proc do |*args|
+              ::ActiveSupport::Notifications.instrument('endpoint_render.grape.start_render')
+              method_api.call(*args)
+            end
+          end
+        end
+
+        # InstanceMethods - implementing instrumentation
+        module InstanceMethods
+          def run(*args)
+            ::ActiveSupport::Notifications.instrument('endpoint_run.grape.start_process')
+            super
+          end
+        end
+      end
+    end
+  end
+end