always propagate tracestate when tracecontext is configured (DataDog#…

…3810) * always propagate tracestate when tracecontext is configured * add support for DD_TRACE_PROPAGATION_EXTRACT_FIRST
martindisch · Nov 20, 2023 · fa1109e · fa1109e
1 parent 1f0aa42
commit fa1109e
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Showing 4 changed files with 78 additions and 5 deletions.
diff --git a/packages/dd-trace/src/config.js b/packages/dd-trace/src/config.js
@@ -309,6 +309,10 @@ class Config {
       options.tracePropagationStyle,
       defaultPropagationStyle
     )
+    const DD_TRACE_PROPAGATION_EXTRACT_FIRST = coalesce(
+      process.env.DD_TRACE_PROPAGATION_EXTRACT_FIRST,
+      false
+    )
     const DD_TRACE_RUNTIME_ID_ENABLED = coalesce(
       options.experimental && options.experimental.runtimeId,
       process.env.DD_TRACE_EXPERIMENTAL_RUNTIME_ID_ENABLED,
@@ -579,6 +583,7 @@ ken|consumer_?(?:id|key|secret)|sign(?:ed|ature)?|auth(?:entication|orization)?)
       inject: DD_TRACE_PROPAGATION_STYLE_INJECT,
       extract: DD_TRACE_PROPAGATION_STYLE_EXTRACT
     }
+    this.tracePropagationExtractFirst = isTrue(DD_TRACE_PROPAGATION_EXTRACT_FIRST)
     this.experimental = {
       runtimeId: isTrue(DD_TRACE_RUNTIME_ID_ENABLED),
       exporter: DD_TRACE_EXPORTER,

diff --git a/packages/dd-trace/src/id.js b/packages/dd-trace/src/id.js
@@ -42,6 +42,18 @@ class Identifier {
   toJSON () {
     return this.toString()
   }
+
+  equals (other) {
+    const length = this._buffer.length
+    const otherLength = other._buffer.length
+
+    // Only compare the bytes available in both IDs.
+    for (let i = length, j = otherLength; i >= 0 && j >= 0; i--, j--) {
+      if (this._buffer[i] !== other._buffer[j]) return false
+    }
+
+    return true
+  }
 }
 
 // Create a buffer, using an optional hexadecimal value if provided.

diff --git a/packages/dd-trace/src/opentracing/propagation/text_map.js b/packages/dd-trace/src/opentracing/propagation/text_map.js
@@ -236,11 +236,20 @@ class TextMapPropagator {
   _extractDatadogContext (carrier) {
     const spanContext = this._extractGenericContext(carrier, traceKey, spanKey, 10)
 
-    if (spanContext) {
-      this._extractOrigin(carrier, spanContext)
-      this._extractBaggageItems(carrier, spanContext)
-      this._extractSamplingPriority(carrier, spanContext)
-      this._extractTags(carrier, spanContext)
+    if (!spanContext) return spanContext
+
+    this._extractOrigin(carrier, spanContext)
+    this._extractBaggageItems(carrier, spanContext)
+    this._extractSamplingPriority(carrier, spanContext)
+    this._extractTags(carrier, spanContext)
+
+    if (this._config.tracePropagationExtractFirst) return spanContext
+
+    const tc = this._extractTraceparentContext(carrier)
+
+    if (tc && spanContext._traceId.equals(tc._traceId)) {
+      spanContext._traceparent = tc._traceparent
+      spanContext._tracestate = tc._tracestate
     }
 
     return spanContext

diff --git a/packages/dd-trace/test/opentracing/propagation/text_map.spec.js b/packages/dd-trace/test/opentracing/propagation/text_map.spec.js
@@ -464,6 +464,40 @@ describe('TextMapPropagator', () => {
       expect(first._spanId.toString(16)).to.equal(spanId)
     })
 
+    it('should always extract tracestate from tracecontext when trace IDs match', () => {
+      textMap['traceparent'] = '00-0000000000000000000000000000007B-0000000000000456-01'
+      textMap['tracestate'] = 'other=bleh,dd=t.foo_bar_baz_:abc_!@#$%^&*()_+`-~;s:2;o:foo;t.dm:-4'
+      config.tracePropagationStyle.extract = ['datadog', 'tracecontext']
+
+      const carrier = textMap
+      const spanContext = propagator.extract(carrier)
+
+      expect(spanContext._tracestate.get('other')).to.equal('bleh')
+    })
+
+    it(`should not extract tracestate from tracecontext when trace IDs don't match`, () => {
+      textMap['traceparent'] = '00-00000000000000000000000000000789-0000000000000456-01'
+      textMap['tracestate'] = 'other=bleh,dd=t.foo_bar_baz_:abc_!@#$%^&*()_+`-~;s:2;o:foo;t.dm:-4'
+      config.tracePropagationStyle.extract = ['datadog', 'tracecontext']
+
+      const carrier = textMap
+      const spanContext = propagator.extract(carrier)
+
+      expect(spanContext._tracestate).to.be.undefined
+    })
+
+    it(`should not extract tracestate from tracecontext when configured to extract first`, () => {
+      textMap['traceparent'] = '00-0000000000000000000000000000007B-0000000000000456-01'
+      textMap['tracestate'] = 'other=bleh,dd=t.foo_bar_baz_:abc_!@#$%^&*()_+`-~;s:2;o:foo;t.dm:-4'
+      config.tracePropagationStyle.extract = ['datadog', 'tracecontext']
+      config.tracePropagationExtractFirst = true
+
+      const carrier = textMap
+      const spanContext = propagator.extract(carrier)
+
+      expect(spanContext._tracestate).to.be.undefined
+    })
+
     describe('with B3 propagation as multiple headers', () => {
       beforeEach(() => {
         config.tracePropagationStyle.extract = ['b3multi']
@@ -746,6 +780,19 @@ describe('TextMapPropagator', () => {
         expect(spanContext._trace.tags['_dd.p.dm']).to.eql('-4')
       })
 
+      it('should propagate other vendors', () => {
+        textMap['traceparent'] = '01-1111aaaa2222bbbb3333cccc4444dddd-5555eeee6666ffff-01'
+        textMap['tracestate'] = 'other=bleh,dd=t.foo_bar_baz_:abc_!@#$%^&*()_+`-~;s:2;o:foo;t.dm:-4'
+        config.tracePropagationStyle.extract = ['tracecontext']
+
+        const carrier = {}
+        const spanContext = propagator.extract(textMap)
+
+        propagator.inject(spanContext, carrier)
+
+        expect(carrier['tracestate']).to.include('other=bleh')
+      })
+
       it('should fix _dd.p.dm if invalid (non-hyphenated) input is received', () => {
         textMap['traceparent'] = '01-1111aaaa2222bbbb3333cccc4444dddd-5555eeee6666ffff-01'
         textMap['tracestate'] = 'other=bleh,dd=t.foo_bar_baz_:abc_!@#$%^&*()_+`-~;s:2;o:foo;t.dm:4'