fix(node): Don't set extra baggage headers (#8657)

if we see that a `sentry-trace` header was already attached on the
`requestOptions`, don't attach sentry trace and baggage headers again.

packages/node/src/integrations/http.ts

@@ -314,10 +314,18 @@ function addHeadersToRequestOptions(
   sentryTraceHeader: string,
   dynamicSamplingContext: Partial<DynamicSamplingContext> | undefined,
 ): void {
+  // Don't overwrite sentry-trace and baggage header if it's already set.
+  const headers = requestOptions.headers || {};
+  if (headers['sentry-trace']) {
+    return;
+  }
+
   __DEBUG_BUILD__ &&
     logger.log(`[Tracing] Adding sentry-trace header ${sentryTraceHeader} to outgoing request to "${requestUrl}": `);
   const sentryBaggage = dynamicSamplingContextToSentryBaggageHeader(dynamicSamplingContext);
-  const sentryBaggageHeader = normalizeBaggageHeader(requestOptions, sentryBaggage);
+  const sentryBaggageHeader =
+    sentryBaggage && sentryBaggage.length > 0 ? normalizeBaggageHeader(requestOptions, sentryBaggage) : undefined;
+
   requestOptions.headers = {
     ...requestOptions.headers,
     'sentry-trace': sentryTraceHeader,
@@ -354,7 +362,6 @@ function normalizeBaggageHeader(
   } else if (Array.isArray(requestOptions.headers.baggage)) {
     return [...requestOptions.headers.baggage, sentryBaggageHeader];
   }
-
   // Type-cast explanation:
   // Technically this the following could be of type `(number | string)[]` but for the sake of simplicity
   // we say this is undefined behaviour, since it would not be baggage spec conform if the user did this.

packages/node/test/integrations/http.test.ts

@@ -19,6 +19,10 @@ const originalHttpGet = http.get;
 const originalHttpRequest = http.request;
 
 describe('tracing', () => {
+  afterEach(() => {
+    sentryCore.getCurrentHub().getScope().setSpan(undefined);
+  });
+
   function createTransactionOnScope(
     customOptions: Partial<NodeClientOptions> = {},
     customContext?: Partial<TransactionContext>,
@@ -178,21 +182,39 @@ describe('tracing', () => {
     ]);
   });
 
+  it("doesn't attach baggage headers if already defined", () => {
+    nock('http://dogs.are.great').get('/').reply(200);
+
+    createTransactionOnScope();
+
+    const request = http.get({
+      host: 'http://dogs.are.great/',
+      headers: {
+        'sentry-trace': '12312012123120121231201212312012-1231201212312012-0',
+        baggage: 'sentry-environment=production,sentry-trace_id=12312012123120121231201212312012',
+      },
+    });
+    const baggage = request.getHeader('baggage');
+    expect(baggage).toEqual('sentry-environment=production,sentry-trace_id=12312012123120121231201212312012');
+  });
+
   it('generates and uses propagation context to attach baggage and sentry-trace header', async () => {
     nock('http://dogs.are.great').get('/').reply(200);
 
+    const { traceId } = sentryCore.getCurrentHub().getScope().getPropagationContext();
+
     const request = http.get('http://dogs.are.great/');
     const sentryTraceHeader = request.getHeader('sentry-trace') as string;
     const baggageHeader = request.getHeader('baggage') as string;
 
     const parts = sentryTraceHeader.split('-');
     expect(parts.length).toEqual(3);
-    expect(parts[0]).toEqual('12312012123120121231201212312012');
+    expect(parts[0]).toEqual(traceId);
     expect(parts[1]).toEqual(expect.any(String));
-    expect(parts[2]).toEqual('1');
+    expect(parts[2]).toEqual('0');
 
     expect(baggageHeader).toEqual(
-      'sentry-environment=production,sentry-release=1.0.0,sentry-user_segment=segmentA,sentry-public_key=dogsarebadatkeepingsecrets,sentry-trace_id=12312012123120121231201212312012,sentry-sample_rate=1,sentry-sampled=true',
+      `sentry-environment=production,sentry-release=1.0.0,sentry-user_segment=segmentA,sentry-public_key=dogsarebadatkeepingsecrets,sentry-trace_id=${traceId}`,
     );
   });