Inject sample rand

Author: Luca Forstner

packages/core/src/tracing/dynamicSamplingContext.ts

@@ -11,6 +11,7 @@ import {
 import { addNonEnumerableProperty, dropUndefinedKeys } from '../utils-hoist/object';
 import { hasTracingEnabled } from '../utils/hasTracingEnabled';
 import { getRootSpan, spanIsSampled, spanToJSON } from '../utils/spanUtils';
+import { getCapturedScopesOnSpan } from './utils';
 
 /**
  * If you change this value, also update the terser plugin config to
@@ -116,7 +117,7 @@ export function getDynamicSamplingContextFromSpan(span: Span): Readonly<Partial<
   // So we end up with an active span that is not sampled (neither positively nor negatively)
   if (hasTracingEnabled()) {
     dsc.sampled = String(spanIsSampled(rootSpan));
-    // TODO(lforst): Grab scope off of root span and put sample_rand on dsc
+    dsc.sample_rand = getCapturedScopesOnSpan(rootSpan).scope?.getPropagationContext().sampleRand.toString();
   }
 
   client.emit('createDsc', dsc, rootSpan);

packages/opentelemetry/src/propagator.ts

@@ -171,7 +171,7 @@ export function getInjectionData(context: Context): {
       dynamicSamplingContext,
       traceId: spanContext.traceId,
       spanId: undefined,
-      sampled: getSamplingDecision(spanContext),
+      sampled: getSamplingDecision(spanContext), // TODO: Do we need to change something here?
     };
   }
 
@@ -184,7 +184,7 @@ export function getInjectionData(context: Context): {
       dynamicSamplingContext,
       traceId: spanContext.traceId,
       spanId: spanContext.spanId,
-      sampled: getSamplingDecision(spanContext),
+      sampled: getSamplingDecision(spanContext), // TODO: Do we need to change something here?
     };
   }