[feat]: add resource labels attribs as span tags and use service.name

src/transform.ts

@@ -73,11 +73,12 @@ function createSpan(
 ): typeof Span {
   // convert to datadog span
   const [ddTraceId, ddSpanId, ddParentId] = getTraceContext(span);
+  const [ddResourceTags, ddResourceServiceName] = getResourceInfo(span);
 
   // generate datadog span base
   const ddSpanBase = new Span(NOOP_TRACER, null, SAMPLER, null, {
     startTime: hrTimeToMilliseconds(span.startTime),
-    tags: tags,
+    tags: Object.assign(tags, ddResourceTags),
     operationName: createSpanName(span),
   });
   const ddSpanBaseContext = ddSpanBase.context();
@@ -95,7 +96,14 @@ function createSpan(
   addSpanType(ddSpanBase, span);
 
   // set datadog specific env and version tags
-  addDatadogTags(ddSpanBase, span, serviceName, env, version);
+  addDatadogTags(
+    ddSpanBase,
+    span,
+    serviceName,
+    env,
+    version,
+    ddResourceServiceName
+  );
 
   // set sampling rate
   setSamplingRate(ddSpanBase, span);
@@ -164,12 +172,13 @@ function addDatadogTags(
   span: ReadableSpan,
   serviceName?: string | undefined,
   env?: string | undefined,
-  version?: string | undefined
+  version?: string | undefined,
+  ddResourceServiceName?: string | undefined
 ): void {
   // set reserved service and resource tags
   ddSpanBase.addTags({
     [DatadogDefaults.RESOURCE_TAG]: createResource(span),
-    [DatadogDefaults.SERVICE_TAG]: serviceName,
+    [DatadogDefaults.SERVICE_TAG]: ddResourceServiceName || serviceName,
   });
 
   // set env tag
@@ -334,3 +343,28 @@ function setSamplingRate(ddSpanBase: typeof Span, span: ReadableSpan): void {
     ddSpanBase.setTag(DatadogDefaults.SAMPLE_RATE_METRIC_KEY, samplingRate);
   }
 }
+
+function getResourceInfo(span: ReadableSpan): any[] {
+  // extract the resource labels/attributes and potential service name to use for spans
+  const ddResourceTags: { [key: string]: any } = {};
+  let resourceServiceName: any;
+  const resource: any = span.resource;
+
+  if (!resource) return [ddResourceTags, resourceServiceName];
+
+  const resourceTags: { [key: string]: string | number } | undefined =
+    resource['labels'] || resource['attributes'];
+
+  if (!resourceTags) return [ddResourceTags, resourceServiceName];
+
+  // the spec around whether this is labels or attributes varies between versions
+  for (const [key, value] of Object.entries(resourceTags)) {
+    if (key === 'service.name') {
+      resourceServiceName = value.toString();
+    } else {
+      ddResourceTags[key] = value.toString();
+    }
+  }
+
+  return [ddResourceTags, resourceServiceName];
+}

test/mocks.ts

@@ -10,6 +10,8 @@ import * as api from '@opentelemetry/api';
 import { Resource } from '@opentelemetry/resources';
 import { TraceState } from '@opentelemetry/core';
 
+export const mockResourceServiceName = 'otel-resource-service-name';
+
 export const mockSpanContextUnsampled = {
   traceId: 'd4cda95b652f4a1592b449d5929fda1b',
   spanId: '6e0c63257de34c92',
@@ -89,8 +91,57 @@ export const mockExandedReadableSpan: any = {
   ],
   duration: [32, 800000000],
   resource: new Resource({
-    service: 'ui',
-    version: 1,
+    zervice: 'ui',
+    otherInfo: 'one',
+    cost: 112.12,
+  }),
+  instrumentationLibrary: {
+    name: 'default',
+    version: '0.0.1',
+  },
+};
+
+export const mockExandedReadableSpanWithResourceService: any = {
+  name: 'my-span',
+  kind: api.SpanKind.INTERNAL,
+  spanContext: mockSpanContextUnsampled,
+  startTime: [1566156729, 709],
+  endTime: [1566156731, 709],
+  ended: true,
+  status: {
+    code: api.CanonicalCode.OK,
+  },
+  attributes: {
+    testBool: true,
+    testString: 'test',
+    testNum: '3.142',
+  },
+  links: [
+    {
+      context: {
+        traceId: 'a4cda95b652f4a1592b449d5929fda1b',
+        spanId: '3e0c63257de34c92',
+      },
+      attributes: {
+        testBool: true,
+        testString: 'test',
+        testNum: 3.142,
+      },
+    },
+  ],
+  events: [
+    {
+      name: 'something happened',
+      attributes: {
+        error: true,
+      },
+      time: [1566156729, 809],
+    },
+  ],
+  duration: [32, 800000000],
+  resource: new Resource({
+    'service.name': mockResourceServiceName,
+    otherInfo: 'one',
     cost: 112.12,
   }),
   instrumentationLibrary: {

test/transform.test.ts

@@ -16,6 +16,8 @@ import {
   mockSpanContextSampled,
   mockSpanContextOrigin,
   mockExandedReadableSpan,
+  mockExandedReadableSpanWithResourceService,
+  mockResourceServiceName,
 } from './mocks';
 
 describe('transform', () => {
@@ -36,8 +38,18 @@ describe('transform', () => {
     return otelSpans;
   };
 
+  const generateOtelSpansWithResourceService = function (
+    options: any
+  ): ReadableSpan[] {
+    const otelSpans = [];
+    const span: ReadableSpan = mockExandedReadableSpanWithResourceService;
+    const updatedSpan = Object.assign(span, options);
+    otelSpans.push(updatedSpan);
+    return otelSpans;
+  };
+
   describe('translateToDatadog', () => {
-    it('should convert an OpenTelemetry span and its properties to a finished DatadogSpan', () => {
+    it('should convert an OpenTelemetry span and its properties, including resource info, to a finished DatadogSpan', () => {
       const spans = generateOtelSpans({ spanContext: spanContextUnsampled });
       const datadogSpans = translateToDatadog(spans, serviceName);
       const datadogSpan = datadogSpans[0];
@@ -66,7 +78,8 @@ describe('transform', () => {
         datadogSpan.start,
         Math.round(hrTimeToMilliseconds(spans[0].startTime) * 1e6)
       );
-      assert.strictEqual(Object.keys(datadogSpan.meta).length, 4);
+
+      assert.strictEqual(Object.keys(datadogSpan.meta).length, 7);
       assert.strictEqual(Object.keys(datadogSpan.metrics).length, 1);
       assert.strictEqual(
         datadogSpan.metrics['_sample_rate'],
@@ -157,5 +170,14 @@ describe('transform', () => {
       const datadogSpan = datadogSpans[0];
       assert.strictEqual(datadogSpan.metrics['_sample_rate'], -1);
     });
+
+    it('should set the resource service.name as dd span service if it exists', () => {
+      const spans = generateOtelSpansWithResourceService({
+        spanContext: spanContextSampled,
+      });
+      const datadogSpans = translateToDatadog(spans, serviceName);
+      const datadogSpan = datadogSpans[0];
+      assert.strictEqual(datadogSpan.service, mockResourceServiceName);
+    });
   });
 });