Refactored: gRPC to use Datadog::Contrib::Integration. (#563)

lib/ddtrace.rb

@@ -55,8 +55,8 @@ def configure(target = configuration, opts = {})
 require 'ddtrace/contrib/faraday/patcher'
 require 'ddtrace/contrib/grape/integration'
 require 'ddtrace/contrib/graphql/patcher'
-require 'ddtrace/contrib/grpc/patcher'
 require 'ddtrace/contrib/http/integration'
+require 'ddtrace/contrib/grpc/integration'
 require 'ddtrace/contrib/integration'
 require 'ddtrace/contrib/mysql2/integration'
 require 'ddtrace/contrib/mongodb/integration'

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

@@ -0,0 +1,16 @@
+require 'ddtrace/contrib/configuration/settings'
+require 'ddtrace/contrib/grpc/ext'
+
+module Datadog
+  module Contrib
+    module GRPC
+      module Configuration
+        # Custom settings for the gRPC integration
+        class Settings < Contrib::Configuration::Settings
+          option :service_name, default: Ext::SERVICE_NAME
+          option :tracer, default: Datadog.tracer
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/grpc/datadog_interceptor/client.rb

@@ -1,3 +1,6 @@
+require 'ddtrace/ext/http'
+require 'ddtrace/contrib/grpc/ext'
+
 module Datadog
   module Contrib
     module GRPC
@@ -11,12 +14,12 @@ def trace(keywords)
             keywords[:metadata] ||= {}
 
             options = {
-              span_type: Datadog::Ext::GRPC::TYPE,
+              span_type: Datadog::Ext::HTTP::TYPE,
               service: datadog_pin.service_name,
               resource: format_resource(keywords[:method])
             }
 
-            tracer.trace('grpc.client', options) do |span|
+            tracer.trace(Ext::SPAN_CLIENT, options) do |span|
               annotate!(span, keywords[:metadata])
 
               yield

lib/ddtrace/contrib/grpc/datadog_interceptor/server.rb

@@ -1,3 +1,6 @@
+require 'ddtrace/ext/http'
+require 'ddtrace/contrib/grpc/ext'
+
 module Datadog
   module Contrib
     module GRPC
@@ -10,15 +13,15 @@ module DatadogInterceptor
         class Server < Base
           def trace(keywords)
             options = {
-              span_type: Datadog::Ext::GRPC::TYPE,
+              span_type: Datadog::Ext::HTTP::TYPE,
               service: datadog_pin.service_name,
               resource: format_resource(keywords[:method])
             }
             metadata = keywords[:call].metadata
 
             set_distributed_context!(tracer, metadata)
 
-            tracer.trace('grpc.service', options) do |span|
+            tracer.trace(Ext::SPAN_SERVICE, options) do |span|
               annotate!(span, metadata)
 
               yield

lib/ddtrace/contrib/grpc/ext.rb

@@ -0,0 +1,14 @@
+module Datadog
+  module Contrib
+    module GRPC
+      # gRPC integration constants
+      module Ext
+        APP = 'grpc'.freeze
+        SERVICE_NAME = 'grpc'.freeze
+
+        SPAN_CLIENT = 'grpc.client'.freeze
+        SPAN_SERVICE = 'grpc.service'.freeze
+      end
+    end
+  end
+end

lib/ddtrace/contrib/grpc/integration.rb

@@ -0,0 +1,38 @@
+require 'ddtrace/contrib/integration'
+require 'ddtrace/contrib/grpc/configuration/settings'
+require 'ddtrace/contrib/grpc/patcher'
+
+module Datadog
+  module Contrib
+    module GRPC
+      # Description of gRPC integration
+      class Integration
+        include Contrib::Integration
+
+        register_as :grpc, auto_patch: true
+
+        def self.version
+          Gem.loaded_specs['grpc'] && Gem.loaded_specs['grpc'].version
+        end
+
+        def self.present?
+          super && defined?(::GRPC)
+        end
+
+        def self.compatible?
+          super \
+            && Gem::Version.new(RUBY_VERSION) >= Gem::Version.new('2.0') \
+            && version >= Gem::Version.new('0.10.0')
+        end
+
+        def default_configuration
+          Configuration::Settings.new
+        end
+
+        def patcher
+          Patcher
+        end
+      end
+    end
+  end
+end

lib/ddtrace/contrib/grpc/patcher.rb

@@ -1,60 +1,50 @@
-# requirements should be kept minimal as Patcher is a shared requirement.
+require 'ddtrace/contrib/patcher'
+require 'ddtrace/contrib/grpc/ext'
 
 module Datadog
   module Contrib
     module GRPC
-      SERVICE = 'grpc'.freeze
-
       # Patcher enables patching of 'grpc' module.
       module Patcher
-        include Base
-        register_as :grpc, auto_patch: true
-        option :tracer, default: Datadog.tracer
-        option :service_name, default: SERVICE
-
-        @patched = false
+        include Contrib::Patcher
 
         module_function
 
-        def patch
-          return false unless compatible?
-          return @patched if @patched
-
-          require 'ddtrace/ext/grpc'
-          require 'ddtrace/propagation/grpc_propagator'
-          require 'ddtrace/contrib/grpc/datadog_interceptor'
-          require 'ddtrace/contrib/grpc/intercept_with_datadog'
-
-          add_pin
-          prepend_interceptor
-
-          @patched = true
-        rescue StandardError => e
-          Datadog::Tracer.log.error("Unable to apply gRPC integration: #{e}")
-        ensure
-          @patched
-        end
-
-        def compatible?
-          defined?(::GRPC::VERSION) && Gem::Version.new(::GRPC::VERSION) >= Gem::Version.new('0.10.0')
+        def patched?
+          done?(:grpc)
         end
 
-        def patched?
-          @patched
+        def patch
+          do_once(:grpc) do
+            begin
+              require 'ddtrace/propagation/grpc_propagator'
+              require 'ddtrace/contrib/grpc/datadog_interceptor'
+              require 'ddtrace/contrib/grpc/intercept_with_datadog'
+
+              add_pin
+              prepend_interceptor
+            rescue StandardError => e
+              Datadog::Tracer.log.error("Unable to apply gRPC integration: #{e}")
+            end
+          end
         end
 
         def add_pin
           Pin.new(
             get_option(:service_name),
-            app: 'grpc',
-            app_type: 'grpc',
+            app: Ext::APP,
+            app_type: Datadog::Ext::AppTypes::WEB,
             tracer: get_option(:tracer)
           ).onto(::GRPC)
         end
 
         def prepend_interceptor
           ::GRPC::InterceptionContext
-            .prepend(Datadog::Contrib::GRPC::InterceptWithDatadog)
+            .send(:prepend, Datadog::Contrib::GRPC::InterceptWithDatadog)
+        end
+
+        def get_option(option)
+          Datadog.configuration[:grpc].get_option(option)
         end
       end
     end

spec/ddtrace/contrib/grpc/datadog_interceptor/client_spec.rb

@@ -46,7 +46,7 @@
 
   shared_examples 'span data contents' do
     specify { expect(span.name).to eq 'grpc.client' }
-    specify { expect(span.span_type).to eq 'grpc' }
+    specify { expect(span.span_type).to eq 'http' }
     specify { expect(span.service).to eq 'rspec' }
     specify { expect(span.resource).to eq 'myservice.endpoint' }
     specify { expect(span.get_tag('error.stack')).to be_nil }

spec/ddtrace/contrib/grpc/datadog_interceptor/server_spec.rb

@@ -15,7 +15,7 @@
 
   shared_examples 'span data contents' do
     specify { expect(span.name).to eq 'grpc.service' }
-    specify { expect(span.span_type).to eq 'grpc' }
+    specify { expect(span.span_type).to eq 'http' }
     specify { expect(span.service).to eq 'rspec' }
     specify { expect(span.resource).to eq 'my.server.endpoint' }
     specify { expect(span.get_tag('error.stack')).to be_nil }

spec/ddtrace/contrib/grpc/interception_context_spec.rb

@@ -19,7 +19,7 @@
     context 'when intercepting on the client' do
       shared_examples 'span data contents' do
         specify { expect(span.name).to eq 'grpc.client' }
-        specify { expect(span.span_type).to eq 'grpc' }
+        specify { expect(span.span_type).to eq 'http' }
         specify { expect(span.service).to eq 'rspec' }
         specify { expect(span.resource).to eq 'myservice.endpoint' }
         specify { expect(span.get_tag('error.stack')).to be_nil }
@@ -60,7 +60,7 @@
 
         specify do
           expect(span.name).to eq 'grpc.client'
-          expect(span.span_type).to eq 'grpc'
+          expect(span.span_type).to eq 'http'
           expect(span.service).to eq 'rspec'
           expect(span.resource).to eq 'myservice.endpoint'
           expect(span.get_tag('error.stack')).to be_nil
@@ -84,7 +84,7 @@
     context 'when intercepting on the server' do
       shared_examples 'span data contents' do
         specify { expect(span.name).to eq 'grpc.service' }
-        specify { expect(span.span_type).to eq 'grpc' }
+        specify { expect(span.span_type).to eq 'http' }
         specify { expect(span.service).to eq 'rspec' }
         specify { expect(span.resource).to eq 'my.server.endpoint' }
         specify { expect(span.get_tag('error.stack')).to be_nil }