fix: ensure the correct ids are serialized and propagated

lib/datadog/opentelemetry/sdk/propagator.rb

@@ -41,8 +41,9 @@ def extract(
           digest = @datadog_propagator.extract(carrier)
           return context unless digest
 
-          trace_id = to_otel_id(digest.trace_id)
-          span_id = to_otel_id(digest.span_id)
+          # Converts the {Numeric} Datadog id object to OpenTelemetry's byte array format.
+          trace_id = [format('%032x', digest.trace_id)].pack('H32')
+          span_id = [format('%016x', digest.trace_id)].pack('H16')
 
           if digest.trace_state || digest.trace_flags
             trace_flags = ::OpenTelemetry::Trace::TraceFlags.from_byte(digest.trace_flags)
@@ -78,14 +79,6 @@ def extract(
         def fields
           []
         end
-
-        private
-
-        # Converts the {Numeric} Datadog id object to OpenTelemetry's byte array format.
-        # This method currently converts an unsigned 64-bit Integer to a binary String.
-        def to_otel_id(dd_id)
-          Array(dd_id).pack('Q')
-        end
       end
     end
   end

lib/datadog/opentelemetry/sdk/span_processor.rb

@@ -85,6 +85,10 @@ def start_datadog_span(span)
           name, kwargs = span_arguments(span, attributes)
 
           datadog_span = Tracing.trace(name, **kwargs)
+          # The Datadog span must have the same ID as the OpenTelemetry span
+          # DEV: We need to set the span ID after the span is created
+          datadog_span.id = span.context.hex_span_id.to_i(16)
+          datadog_span.trace_id = span.context.hex_trace_id.to_i(16)
 
           datadog_span.set_error([nil, span.status.description]) unless span.status.ok?
           datadog_span.set_tags(span.attributes)

lib/datadog/tracing/span_operation.rb

@@ -25,16 +25,8 @@ class SpanOperation
 
       # Span attributes
       # NOTE: In the future, we should drop the me
-      attr_reader \
-        :end_time,
-        :id,
-        :name,
-        :parent_id,
-        :resource,
-        :service,
-        :start_time,
-        :trace_id,
-        :type
+      attr_accessor :id, :trace_id
+      attr_reader :end_time, :name, :parent_id, :resource, :service, :start_time, :type
       attr_accessor :links, :status
 
       def initialize(
@@ -421,6 +413,12 @@ def message
         end
       end
 
+      # Provides a mechanism to override the automatically generated span ID
+      # @param id [Integer] the span ID
+
+      # Provides a mechanism to override the automatically generated trace ID
+      # @param trace_id [Integer] the trace ID
+
       private
 
       # Keep span reference private: we don't want users

spec/datadog/opentelemetry_spec.rb

@@ -329,6 +329,17 @@
             expect(parent).to be_root_span
             expect(child.parent_id).to eq(parent.id)
           end
+
+          it 'the underlying datadog spans has the same span_id as the otel spans' do
+            existing_span.finish
+            start_span.finish
+            # parent otel span generates a Datadog span with the same ids
+            expect(existing_span.context.hex_trace_id.to_i(16)).to eq(parent.trace_id)
+            expect(existing_span.context.hex_span_id.to_i(16)).to eq(parent.id)
+            # child otel span generates a Datadog span with the same ids
+            expect(start_span.context.hex_trace_id.to_i(16)).to eq(child.trace_id)
+            expect(start_span.context.hex_span_id.to_i(16)).to eq(child.id)
+          end
         end
       end
 
@@ -802,7 +813,7 @@ def headers
         context 'with TraceContext headers' do
           let(:carrier) do
             {
-              'traceparent' => '00-00000000000000001111111111111111-2222222222222222-01'
+              'traceparent' => '00-11111111111111111111111111111111-2222222222222222-01'
             }
           end
 
@@ -817,7 +828,7 @@ def headers
               otel_tracer.in_span('otel') {}
             end
 
-            expect(span.trace_id).to eq(0x00000000000000001111111111111111)
+            expect(span.trace_id).to eq(0x11111111111111111111111111111111)
             expect(span.parent_id).to eq(0x2222222222222222)
           end
         end

spec/datadog/tracing/span_operation_spec.rb

@@ -319,6 +319,24 @@
     end
   end
 
+  describe '#id=' do
+    subject!(:id=) { span_op.id = id }
+
+    context 'with a valid 64 bit integer' do
+      let(:id) { 2 ^ 64 - 1 }
+      it { expect(span_op.id).to eq(id) }
+    end
+  end
+
+  describe '#trace_id=' do
+    subject!(:trace_id=) { span_op.trace_id = trace_id }
+
+    context 'with a valid 128 bit integer' do
+      let(:trace_id) { 2 ^ 128 - 1 }
+      it { expect(span_op.trace_id).to eq(trace_id) }
+    end
+  end
+
   describe '#measure' do
     subject(:measure) { span_op.measure(&block) }