Remove default value from peer.service tag

lib/datadog/core/telemetry/event.rb

@@ -103,6 +103,11 @@ def configuration
                 config.tracing.contrib.global_default_service_name.enabled,
                 seq_id
               ),
+              conf_value(
+                'DD_TRACE_PEER_SERVICE_DEFAULTS_ENABLED',
+                config.tracing.contrib.peer_service_defaults,
+                seq_id
+              ),
             ]
 
             peer_service_mapping_str = ''

lib/datadog/tracing/configuration/ext.rb

@@ -16,6 +16,7 @@ module Ext
         # @public_api
         module SpanAttributeSchema
           ENV_GLOBAL_DEFAULT_SERVICE_NAME_ENABLED = 'DD_TRACE_REMOVE_INTEGRATION_SERVICE_NAMES_ENABLED'
+          ENV_PEER_SERVICE_DEFAULTS_ENABLED = 'DD_TRACE_PEER_SERVICE_DEFAULTS_ENABLED'
           ENV_PEER_SERVICE_MAPPING = 'DD_TRACE_PEER_SERVICE_MAPPING'
         end
 

lib/datadog/tracing/contrib/extensions.rb

@@ -123,6 +123,17 @@ def self.included(base)
                     o.default({})
                   end
 
+                  # Enables population the `peer.service` tag.
+                  # When disabled, other peer service related configurations have no effect.
+                  #
+                  # @default `DD_TRACE_PEER_SERVICE_DEFAULTS_ENABLED` environment variable, otherwise `false`
+                  # @return [Boolean]
+                  option :peer_service_defaults do |o|
+                    o.env Tracing::Configuration::Ext::SpanAttributeSchema::ENV_PEER_SERVICE_DEFAULTS_ENABLED
+                    o.type :bool
+                    o.default false
+                  end
+
                   # Global service name behavior
                   settings :global_default_service_name do
                     # Overrides default service name to global service name

lib/datadog/tracing/contrib/span_attribute_schema.rb

@@ -21,9 +21,14 @@ def self.fetch_service_name(env, default)
         end
 
         def self.set_peer_service!(span, sources)
+          config = Datadog.configuration.tracing.contrib
+
+          # If `peer_service_defaults` is disabled, we only read peer service from an explicitly set `peer.service` tag
+          sources = Datadog::Tracing::Contrib::SpanAttributeSchema::REFLEXIVE_SOURCES unless config.peer_service_defaults
+
           # Acquire all peer.service values as well as any potential remapping
           peer_service_val, peer_service_source = set_peer_service_from_source(span, sources)
-          remap_val = Datadog.configuration.tracing.contrib.peer_service_mapping[peer_service_val]
+          remap_val = config.peer_service_mapping[peer_service_val]
 
           # Only continue to setting peer.service if actual source is found
           return false unless peer_service_source

sig/datadog/tracing/configuration/ext.rbs

@@ -7,6 +7,7 @@ module Datadog
         ENV_TRACE_ID_128_BIT_GENERATION_ENABLED: "DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED"
         module SpanAttributeSchema
           ENV_GLOBAL_DEFAULT_SERVICE_NAME_ENABLED: "DD_TRACE_REMOVE_INTEGRATION_SERVICE_NAMES_ENABLED"
+          ENV_PEER_SERVICE_DEFAULTS_ENABLED: string
           ENV_PEER_SERVICE_MAPPING: "DD_TRACE_PEER_SERVICE_MAPPING"
         end
         module Analytics

sig/datadog/tracing/contrib/extensions.rbs

@@ -9,8 +9,8 @@ module Datadog
         module Configuration
           def configure: () ?{ () -> untyped } -> untyped
           module Settings
-            InvalidIntegrationError: untyped
-            def instrument: (untyped integration_name, ?::Hash[untyped, untyped] options) ?{ () -> untyped } -> untyped
+            InvalidIntegrationError: StandardError
+            def instrument: (Symbol integration_name, ?::Hash[Symbol, untyped] options) ?{ () -> untyped } -> Contrib::Integration
             alias use instrument
             def []: (untyped integration_name, ?::Symbol key) -> untyped
             def integrations_pending_activation: () -> untyped

sig/datadog/tracing/contrib/span_attribute_schema.rbs

@@ -2,20 +2,18 @@ module Datadog
   module Tracing
     module Contrib
       module SpanAttributeSchema
-        PEER_SERVICE_SOURCE_DB: Array[string]
-        PEER_SERVICE_SOURCE_DEFAULT: Array[string]
-        PEER_SERVICE_SOURCE_MSG: Array[string]
-        PEER_SERVICE_SOURCE_RPC: Array[string]
+        NO_SOURCE: Array[string]
+        REFLEXIVE_SOURCES: Array[string]
 
         def self?.fetch_service_name: (string env, string default) -> bool
 
-        def not_empty_tag?: (string) -> bool
+        def self.filter_peer_service_sources: (SpanOperation span, Array[string] sources) -> Array[string]
 
-        def set_peer_service: -> bool
+        def self.not_empty_tag?: (string tag) -> bool
 
-        def set_peer_service?: -> bool
+        def self.set_peer_service!: (SpanOperation span, Array[string] sources) -> bool
 
-        def set_peer_service_from_source: -> bool
+        def self.set_peer_service_from_source: (SpanOperation span, Array[string] sources) -> [string, string]
       end
     end
   end

spec/datadog/core/telemetry/event_spec.rb

@@ -52,6 +52,7 @@ def contain_configuration(*array)
           ['DD_AGENT_TRANSPORT', 'TCP'],
           ['DD_TRACE_SAMPLE_RATE', '0.5'],
           ['DD_TRACE_REMOVE_INTEGRATION_SERVICE_NAMES_ENABLED', true],
+          ['DD_TRACE_PEER_SERVICE_DEFAULTS_ENABLED', false],
           ['DD_TRACE_PEER_SERVICE_MAPPING', 'foo:bar'],
           ['logger.level', 0],
           ['profiling.advanced.code_provenance_enabled', true],

spec/datadog/tracing/contrib/extensions_spec.rb

@@ -91,6 +91,30 @@
             end
           end
 
+          describe '#peer_service_defaults' do
+            subject { settings.contrib.peer_service_defaults }
+
+            context 'when given environment variable DD_TRACE_PEER_SERVICE_DEFAULTS_ENABLED' do
+              around do |example|
+                ClimateControl.modify('DD_TRACE_PEER_SERVICE_DEFAULTS_ENABLED' => env_var) do
+                  example.run
+                end
+              end
+
+              context 'is not defined' do
+                let(:env_var) { nil }
+
+                it { is_expected.to be false }
+              end
+
+              context 'is defined' do
+                let(:env_var) { 'true' }
+
+                it { is_expected.to be true }
+              end
+            end
+          end
+
           describe '#global_default_service_name_enabled' do
             subject { settings.contrib.global_default_service_name.enabled }
 

spec/datadog/tracing/contrib/integration_examples.rb

@@ -5,12 +5,25 @@
     skip('No let(:peer_service_source) defined.') unless defined?(peer_service_source)
   end
 
-  context 'extracted peer service' do
+  context 'with default peer services enabled' do
+    around do |example|
+      ClimateControl.modify('DD_TRACE_PEER_SERVICE_DEFAULTS_ENABLED' => 'true') do
+        example.run
+      end
+    end
+
     it 'contains extracted peer service tag' do
       expect(span.get_tag('peer.service')).to eq(peer_service_val)
       expect(span.get_tag('_dd.peer.service.source')).to eq(peer_service_source)
     end
   end
+
+  context 'with default peer services disabled' do
+    it 'does not contain extracted peer service tag' do
+      expect(span.get_tag('peer.service')).to be_nil
+      expect(span.get_tag('_dd.peer.service.source')).to be_nil
+    end
+  end
 end
 
 RSpec.shared_examples 'a non-peer service span' do

spec/datadog/tracing/contrib/peer_service_configuration_examples.rb

@@ -14,19 +14,47 @@
       end
     end
 
-    context 'when env_var configured' do
-      it 'expects peer.service to equal env var value and source to be peer.service' do
-        expect(span.get_tag('peer.service')).to eq('configured_peer_service_via_env_var')
-        expect(span.get_tag('_dd.peer.service.source')).to eq('peer.service')
+    context 'with default peer services enabled' do
+      around do |example|
+        ClimateControl.modify('DD_TRACE_PEER_SERVICE_DEFAULTS_ENABLED' => 'true') do
+          example.run
+        end
+      end
+
+      context 'when env_var configured' do
+        it 'expects peer.service to equal env var value and source to be peer.service' do
+          expect(span.get_tag('peer.service')).to eq('configured_peer_service_via_env_var')
+          expect(span.get_tag('_dd.peer.service.source')).to eq('peer.service')
+        end
+      end
+
+      context 'when peer_service option is configured' do
+        let(:configuration_options) { { peer_service: 'configured_peer_service' } }
+
+        it 'expects peer.service to equal configured value and source to be peer.service' do
+          expect(span.get_tag('peer.service')).to eq(configuration_options[:peer_service])
+          expect(span.get_tag('_dd.peer.service.source')).to eq('peer.service')
+        end
       end
     end
 
-    context 'when peer_service option is configured' do
-      let(:configuration_options) { { peer_service: 'configured_peer_service' } }
+    context 'with default peer services disabled' do
+      # We still set the `peer.service` tag when it is explicitly configured
+
+      context 'when env_var configured' do
+        it 'expects peer.service to equal env var value and source to be peer.service' do
+          expect(span.get_tag('peer.service')).to eq('configured_peer_service_via_env_var')
+          expect(span.get_tag('_dd.peer.service.source')).to eq('peer.service')
+        end
+      end
+
+      context 'when peer_service option is configured' do
+        let(:configuration_options) { { peer_service: 'configured_peer_service' } }
 
-      it 'expects peer.service to equal configured value and source to be peer.service' do
-        expect(span.get_tag('peer.service')).to eq(configuration_options[:peer_service])
-        expect(span.get_tag('_dd.peer.service.source')).to eq('peer.service')
+        it 'expects peer.service to equal configured value and source to be peer.service' do
+          expect(span.get_tag('peer.service')).to eq(configuration_options[:peer_service])
+          expect(span.get_tag('_dd.peer.service.source')).to eq('peer.service')
+        end
       end
     end
   end

spec/datadog/tracing/contrib/span_attribute_schema_spec.rb

@@ -52,6 +52,14 @@
 
   describe '#set_peer_service!' do
     let(:span) { Datadog::Tracing::Span.new('testPeerServiceLogicSpan', parent_id: 0) }
+    subject(:set_peer_service!) { described_class.set_peer_service!(span, precursors) }
+
+    around do |example|
+      ClimateControl.modify('DD_TRACE_PEER_SERVICE_DEFAULTS_ENABLED' => 'true') do
+        example.run
+      end
+    end
+
     context 'precursor tags set' do
       context 'AWS Span' do
         let(:precursors) do
@@ -79,6 +87,31 @@
             span.clear_tag(precursor)
           end
         end
+
+        context 'peer service defaults disabled' do
+          around do |example|
+            ClimateControl.modify('DD_TRACE_PEER_SERVICE_DEFAULTS_ENABLED' => 'false') do
+              example.run
+            end
+          end
+
+          it 'does not set peer.service' do
+            span.set_tag('aws_service', 'test-service')
+            span.set_tag('span.kind', 'client')
+            precursors.each do |precursor|
+              span.set_tag(precursor, 'test-' << precursor)
+
+              set_peer_service!
+              expect(span.get_tag('peer.service')).to be_nil
+              expect(span.get_tag('_dd.peer.service.source')).to be_nil
+              expect(span.get_tag('_dd.peer.service.remapped_from')).to be_nil
+
+              span.clear_tag('peer.service')
+              span.clear_tag('_dd.peer.service.source')
+              span.clear_tag(precursor)
+            end
+          end
+        end
       end
 
       context 'DB Span' do
@@ -257,6 +290,23 @@
           expect(span.get_tag('_dd.peer.service.remapped_from')).to eq('peer-service-value')
         end
       end
+
+      context 'peer service defaults disabled' do
+        around do |example|
+          ClimateControl.modify('DD_TRACE_PEER_SERVICE_DEFAULTS_ENABLED' => 'false') do
+            example.run
+          end
+        end
+
+        it 'keeps explicit peer.service' do
+          span.set_tag('peer.service', 'peer-service-value')
+
+          set_peer_service!
+
+          expect(span.get_tag('peer.service')).to eq('peer-service-value')
+          expect(span.get_tag('_dd.peer.service.source')).to eq('peer.service')
+        end
+      end
     end
 
     context 'remapping tags' do