feat(telemetry): Add process tags to instrumentation telemetry

lib/datadog/core/telemetry/request.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require_relative '../environment/platform'
+require_relative '../environment/process'
 require_relative '../utils/hash'
 
 module Datadog
@@ -23,6 +24,7 @@ def build_payload(event, seq_id, api_version: 'v2', debug: false)
               seq_id: seq_id,
               tracer_time: Core::Utils::Time.now.to_i,
             }
+            tag_process_tags!(hash)
             hash.compact!
             hash
           end
@@ -64,6 +66,15 @@ def host
               kernel_version: Core::Environment::Platform.kernel_version
             }
           end
+
+          def tag_process_tags!(hash)
+            return unless Datadog.configuration.experimental_propagate_process_tags_enabled
+
+            process_tags = Core::Environment::Process.serialized
+            return if process_tags.empty?
+
+            hash[:process_tags] = process_tags
+          end
         end
       end
     end

sig/datadog/core/telemetry/request.rbs

@@ -8,6 +8,7 @@ module Datadog
 
         def self.application: -> ::Hash[Symbol, untyped]
         def self.host: -> ::Hash[Symbol, untyped]
+        def self.tag_process_tags!: (Hash[Symbol, untyped] hash) -> void
       end
     end
   end

spec/datadog/core/telemetry/integration/telemetry_spec.rb

@@ -298,6 +298,56 @@
         )
       end
     end
+
+    describe 'process tags' do
+      include_context 'disable profiling'
+
+      before do
+        settings.telemetry.dependency_collection = true
+      end
+
+      context 'when process tags propagation is enabled' do
+        it 'includes process tags in the payload when the process tags have values' do
+          allow(Datadog.configuration).to receive(:experimental_propagate_process_tags_enabled).and_return(true)
+
+          component.start(false, components: Datadog.send(:components))
+          component.flush
+          expect(sent_payloads.length).to eq 2
+
+          payload = sent_payloads[0]
+          expect(payload.fetch(:payload)).to include('process_tags' => String)
+          expect(payload.dig(:payload, 'process_tags')).to include('entrypoint.workdir')
+          expect(payload.dig(:payload, 'process_tags')).to include('entrypoint.basedir')
+          expect(payload.dig(:payload, 'process_tags')).to include('entrypoint.type')
+          expect(payload.dig(:payload, 'process_tags')).to include('entrypoint.name')
+        end
+
+        it 'does not include process_tags when serialized value is empty' do
+          allow(Datadog.configuration).to receive(:experimental_propagate_process_tags_enabled).and_return(true)
+          allow(Datadog::Core::Environment::Process).to receive(:serialized).and_return('')
+
+          component.start(false, components: Datadog.send(:components))
+          component.flush
+          expect(sent_payloads.length).to eq 2
+
+          payload = sent_payloads[0]
+          expect(payload.fetch(:payload)).not_to have_key('process_tags')
+        end
+      end
+
+      context 'when process tags propagation is disabled' do
+        it 'does not include process_tags in the payload' do
+          allow(Datadog.configuration).to receive(:experimental_propagate_process_tags_enabled).and_return(false)
+
+          component.start(false, components: Datadog.send(:components))
+          component.flush
+          expect(sent_payloads.length).to eq 2
+
+          payload = sent_payloads[0]
+          expect(payload.fetch(:payload)).not_to have_key('process_tags')
+        end
+      end
+    end
   end
 
   let(:handler_proc) do