implement w3c phase 3 (#4325)

* implent w3c phase 3
DataDog · Jun 5, 2024 · 05eeb70 · 05eeb70
1 parent 56121ca
commit 05eeb70
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Showing 4 changed files with 87 additions and 12 deletions.
diff --git a/ext/tags.d.ts b/ext/tags.d.ts
@@ -10,6 +10,7 @@ declare const tags: {
   MANUAL_DROP: 'manual.drop'
   MEASURED: '_dd.measured'
   BASE_SERVICE: '_dd.base_service'
+  DD_PARENT_ID: '_dd.parent_id'
   HTTP_URL: 'http.url'
   HTTP_METHOD: 'http.method'
   HTTP_STATUS_CODE: 'http.status_code'

diff --git a/ext/tags.js b/ext/tags.js
@@ -13,6 +13,7 @@ const tags = {
   MANUAL_DROP: 'manual.drop',
   MEASURED: '_dd.measured',
   BASE_SERVICE: '_dd.base_service',
+  DD_PARENT_ID: '_dd.parent_id',
 
   // HTTP
   HTTP_URL: 'http.url',

diff --git a/packages/dd-trace/src/opentracing/propagation/text_map.js b/packages/dd-trace/src/opentracing/propagation/text_map.js
@@ -5,6 +5,7 @@ const id = require('../../id')
 const DatadogSpanContext = require('../span_context')
 const log = require('../../log')
 const TraceState = require('./tracestate')
+const tags = require('../../../../../ext/tags')
 
 const { AUTO_KEEP, AUTO_REJECT, USER_KEEP } = require('../../../../../ext/priority')
 
@@ -39,6 +40,7 @@ const tracestateTagKeyFilter = /[^\x21-\x2b\x2d-\x3c\x3e-\x7e]/g
 // Tag values in tracestate replace ',', '~' and ';' with '_'
 const tracestateTagValueFilter = /[^\x20-\x2b\x2d-\x3a\x3c-\x7d]/g
 const invalidSegment = /^0+$/
+const zeroTraceId = '0000000000000000'
 
 class TextMapPropagator {
   constructor (config) {
@@ -175,9 +177,9 @@ class TextMapPropagator {
         // SpanContext was created by a ddtrace span.
         // Last datadog span id should be set to the current span.
         state.set('p', spanContext._spanId)
-      } else if (spanContext._trace.tags['_dd.parent_id']) {
+      } else if (spanContext._trace.tags[tags.DD_PARENT_ID]) {
         // Propagate the last Datadog span id set on the remote span.
-        state.set('p', spanContext._trace.tags['_dd.parent_id'])
+        state.set('p', spanContext._trace.tags[tags.DD_PARENT_ID])
       }
       state.set('s', priority)
       if (mechanism) {
@@ -214,9 +216,56 @@ class TextMapPropagator {
     return this._config.tracePropagationStyle[mode].includes(name)
   }
 
+  _hasTraceIdConflict (w3cSpanContext, firstSpanContext) {
+    return w3cSpanContext !== null &&
+           firstSpanContext.toTraceId(true) === w3cSpanContext.toTraceId(true) &&
+           firstSpanContext.toSpanId() !== w3cSpanContext.toSpanId()
+  }
+
+  _hasParentIdInTags (spanContext) {
+    return tags.DD_PARENT_ID in spanContext._trace.tags &&
+      spanContext._trace.tags[tags.DD_PARENT_ID] !== zeroTraceId
+  }
+
+  _updateParentIdFromDdHeaders (carrier, firstSpanContext) {
+    const ddCtx = this._extractDatadogContext(carrier)
+    if (ddCtx !== null) {
+      firstSpanContext._trace.tags[tags.DD_PARENT_ID] = ddCtx._spanId.toString().padStart(16, '0')
+    }
+  }
+
+  _resolveTraceContextConflicts (w3cSpanContext, firstSpanContext, carrier) {
+    if (!this._hasTraceIdConflict(w3cSpanContext, firstSpanContext)) {
+      return firstSpanContext
+    }
+    if (this._hasParentIdInTags(w3cSpanContext)) {
+      // tracecontext headers contain a p value, ensure this value is sent to backend
+      firstSpanContext._trace.tags[tags.DD_PARENT_ID] = w3cSpanContext._trace.tags[tags.DD_PARENT_ID]
+    } else {
+      // if p value is not present in tracestate, use the parent id from the datadog headers
+      this._updateParentIdFromDdHeaders(carrier, firstSpanContext)
+    }
+    // the span_id in tracecontext takes precedence over the first extracted propagation style
+    firstSpanContext._spanId = w3cSpanContext._spanId
+    return firstSpanContext
+  }
+
   _extractSpanContext (carrier) {
+    let spanContext = null
     for (const extractor of this._config.tracePropagationStyle.extract) {
-      let spanContext = null
+      // add logic to ensure tracecontext headers takes precedence over other extracted headers
+      if (spanContext !== null) {
+        if (this._config.tracePropagationExtractFirst) {
+          return spanContext
+        }
+        if (extractor !== 'tracecontext') {
+          continue
+        }
+        spanContext = this._resolveTraceContextConflicts(
+          this._extractTraceparentContext(carrier), spanContext, carrier)
+        break
+      }
+
       switch (extractor) {
         case 'datadog':
           spanContext = this._extractDatadogContext(carrier)
@@ -238,13 +287,9 @@ class TextMapPropagator {
         default:
           log.warn(`Unknown propagation style: ${extractor}`)
       }
-
-      if (spanContext !== null) {
-        return spanContext
-      }
     }
 
-    return this._extractSqsdContext(carrier)
+    return spanContext || this._extractSqsdContext(carrier)
   }
 
   _extractDatadogContext (carrier) {
@@ -354,7 +399,7 @@ class TextMapPropagator {
         for (const [key, value] of state.entries()) {
           switch (key) {
             case 'p': {
-              spanContext._trace.tags['_dd.parent_id'] = value
+              spanContext._trace.tags[tags.DD_PARENT_ID] = value
               break
             }
             case 's': {
@@ -387,8 +432,8 @@ class TextMapPropagator {
         }
       })
 
-      if (!spanContext._trace.tags['_dd.parent_id']) {
-        spanContext._trace.tags['_dd.parent_id'] = '0000000000000000'
+      if (!spanContext._trace.tags[tags.DD_PARENT_ID]) {
+        spanContext._trace.tags[tags.DD_PARENT_ID] = zeroTraceId
       }
 
       this._extractBaggageItems(carrier, spanContext)
@@ -531,7 +576,7 @@ class TextMapPropagator {
 
     const tid = traceId.substring(0, 16)
 
-    if (tid === '0000000000000000') return
+    if (tid === zeroTraceId) return
 
     spanContext._trace.tags['_dd.p.tid'] = tid
   }

diff --git a/packages/dd-trace/test/opentracing/propagation/text_map.spec.js b/packages/dd-trace/test/opentracing/propagation/text_map.spec.js
@@ -523,6 +523,34 @@ describe('TextMapPropagator', () => {
       expect(spanContext._tracestate).to.be.undefined
     })
 
+    it('extracts span_id from tracecontext headers and stores datadog parent-id in trace_distributed_tags', () => {
+      textMap['x-datadog-trace-id'] = '61185'
+      textMap['x-datadog-parent-id'] = '15'
+      textMap.traceparent = '00-0000000000000000000000000000ef01-0000000000011ef0-01'
+      config.tracePropagationStyle.extract = ['datadog', 'tracecontext']
+
+      const carrier = textMap
+      const spanContext = propagator.extract(carrier)
+      expect(parseInt(spanContext._spanId.toString(), 16)).to.equal(73456)
+      expect(parseInt(spanContext._traceId.toString(), 16)).to.equal(61185)
+      expect(spanContext._trace.tags).to.have.property('_dd.parent_id', '000000000000000f')
+    })
+
+    it('extracts span_id from tracecontext headers and stores p value from tracestate in trace_distributed_tags',
+      () => {
+        textMap['x-datadog-trace-id'] = '61185'
+        textMap['x-datadog-parent-id'] = '15'
+        textMap.traceparent = '00-0000000000000000000000000000ef01-0000000000011ef0-01'
+        textMap.tracestate = 'other=bleh,dd=p:0000000000000001;s:2;o:foo;t.dm:-4'
+        config.tracePropagationStyle.extract = ['datadog', 'tracecontext']
+
+        const carrier = textMap
+        const spanContext = propagator.extract(carrier)
+        expect(parseInt(spanContext._spanId.toString(), 16)).to.equal(73456)
+        expect(parseInt(spanContext._traceId.toString(), 16)).to.equal(61185)
+        expect(spanContext._trace.tags).to.have.property('_dd.parent_id', '0000000000000001')
+      })
+
     describe('with B3 propagation as multiple headers', () => {
       beforeEach(() => {
         config.tracePropagationStyle.extract = ['b3multi']