feat(core): Send Baggage in Envelope Header (#5104)

This patch Introduces the first step of getting Dynamic Sampling working with the JS SDKs. It adds a very simple approach of attaching baggage to the envelope header of a transaction's event envelope. It does not take immutability of baggage in multiple transactions per trace scenarios into account. This is something we have to address when we're going to add the baggage header to outgoing requests. However, the simple approach should be enough to send baggage information to relay to get DS working on individual transactions.

Author: Lms24

packages/core/src/baseclient.ts

@@ -618,7 +618,7 @@ export abstract class BaseClient<O extends ClientOptions> implements Client<O> {
           throw new SentryError('`beforeSend` returned `null`, will not send event.');
         }
 
-        const session = scope && scope.getSession && scope.getSession();
+        const session = scope && scope.getSession();
         if (!isTransaction && session) {
           this._updateSessionFromEvent(session, processedEvent);
         }

packages/core/src/envelope.ts

@@ -2,6 +2,7 @@ import {
   DsnComponents,
   Event,
   EventEnvelope,
+  EventEnvelopeHeaders,
   EventItem,
   SdkInfo,
   SdkMetadata,
@@ -10,7 +11,15 @@ import {
   SessionEnvelope,
   SessionItem,
 } from '@sentry/types';
-import { createEnvelope, dsnToString } from '@sentry/utils';
+import {
+  BaggageObj,
+  createBaggage,
+  createEnvelope,
+  dropUndefinedKeys,
+  dsnToString,
+  isBaggageEmpty,
+  serializeBaggage,
+} from '@sentry/utils';
 
 /** Extract sdk info from from the API metadata */
 function getSdkMetadataForEnvelopeHeader(metadata?: SdkMetadata): SdkInfo | undefined {
@@ -101,12 +110,8 @@ export function createEventEnvelope(
   // TODO: This is NOT part of the hack - DO NOT DELETE
   delete event.sdkProcessingMetadata;
 
-  const envelopeHeaders = {
-    event_id: event.event_id as string,
-    sent_at: new Date().toISOString(),
-    ...(sdkInfo && { sdk: sdkInfo }),
-    ...(!!tunnel && { dsn: dsnToString(dsn) }),
-  };
+  const envelopeHeaders = createEventEnvelopeHeaders(event, sdkInfo, tunnel, dsn);
+
   const eventItem: EventItem = [
     {
       type: eventType,
@@ -116,3 +121,31 @@ export function createEventEnvelope(
   ];
   return createEnvelope<EventEnvelope>(envelopeHeaders, [eventItem]);
 }
+
+function createEventEnvelopeHeaders(
+  event: Event,
+  sdkInfo: SdkInfo | undefined,
+  tunnel: string | undefined,
+  dsn: DsnComponents,
+): EventEnvelopeHeaders {
+  const baggage =
+    event.type === 'transaction' &&
+    createBaggage(
+      dropUndefinedKeys({
+        environment: event.environment,
+        release: event.release,
+        transaction: event.transaction,
+        userid: event.user && event.user.id,
+        // user.segment currently doesn't exist explicitly in interface User (just as a record key)
+        usersegment: event.user && event.user.segment,
+      } as BaggageObj),
+    );
+
+  return {
+    event_id: event.event_id as string,
+    sent_at: new Date().toISOString(),
+    ...(sdkInfo && { sdk: sdkInfo }),
+    ...(!!tunnel && { dsn: dsnToString(dsn) }),
+    ...(baggage && !isBaggageEmpty(baggage) && { baggage: serializeBaggage(baggage) }),
+  };
+}

packages/core/test/lib/envelope.test.ts

@@ -0,0 +1,54 @@
+import { DsnComponents, Event } from '@sentry/types';
+
+import { createEventEnvelope } from '../../src/envelope';
+
+const testDsn: DsnComponents = { protocol: 'https', projectId: 'abc', host: 'testry.io' };
+
+describe('createEventEnvelope', () => {
+  describe('baggage header', () => {
+    it("doesn't add baggage header if event is not a transaction", () => {
+      const event: Event = {};
+      const envelopeHeaders = createEventEnvelope(event, testDsn)[0];
+
+      expect(envelopeHeaders).toBeDefined();
+      expect(envelopeHeaders.baggage).toBeUndefined();
+    });
+
+    it("doesn't add baggage header if no baggage data is available", () => {
+      const event: Event = {
+        type: 'transaction',
+      };
+      const envelopeHeaders = createEventEnvelope(event, testDsn)[0];
+
+      expect(envelopeHeaders).toBeDefined();
+      expect(envelopeHeaders.baggage).toBeUndefined();
+    });
+
+    const testTable: Array<[string, Event, string]> = [
+      ['adds only baggage item', { type: 'transaction', release: '1.0.0' }, 'sentry-release=1.0.0'],
+      [
+        'adds two baggage items',
+        { type: 'transaction', release: '1.0.0', environment: 'prod' },
+        'sentry-environment=prod,sentry-release=1.0.0',
+      ],
+      [
+        'adds all baggageitems',
+        {
+          type: 'transaction',
+          release: '1.0.0',
+          environment: 'prod',
+          user: { id: 'bob', segment: 'segmentA' },
+          transaction: 'TX',
+        },
+        'sentry-environment=prod,sentry-release=1.0.0,sentry-transaction=TX,sentry-userid=bob,sentry-usersegment=segmentA',
+      ],
+    ];
+    it.each(testTable)('%s', (_: string, event, serializedBaggage) => {
+      const envelopeHeaders = createEventEnvelope(event, testDsn)[0];
+
+      expect(envelopeHeaders).toBeDefined();
+      expect(envelopeHeaders.baggage).toBeDefined();
+      expect(envelopeHeaders.baggage).toEqual(serializedBaggage);
+    });
+  });
+});

packages/integration-tests/suites/tracing/baggage/init.js

@@ -0,0 +1,16 @@
+import * as Sentry from '@sentry/browser';
+import { Integrations } from '@sentry/tracing';
+
+window.Sentry = Sentry;
+
+Sentry.init({
+  dsn: 'https://[email protected]/1337',
+  integrations: [new Integrations.BrowserTracing({ tracingOrigins: [/.*/] })],
+  environment: 'production',
+  tracesSampleRate: 1,
+});
+
+Sentry.configureScope(scope => {
+  scope.setUser({ id: 'user123', segment: 'segmentB' });
+  scope.setTransactionName('testTransactionBaggage');
+});

packages/integration-tests/suites/tracing/baggage/test.ts

@@ -0,0 +1,16 @@
+import { expect } from '@playwright/test';
+import { Event, EventEnvelopeHeaders } from '@sentry/types';
+
+import { sentryTest } from '../../../utils/fixtures';
+import { envelopeHeaderRequestParser, getFirstSentryEnvelopeRequest } from '../../../utils/helpers';
+
+sentryTest('should send baggage data in transaction envelope header', async ({ getLocalTestPath, page }) => {
+  const url = await getLocalTestPath({ testDir: __dirname });
+
+  const envHeader = await getFirstSentryEnvelopeRequest<EventEnvelopeHeaders>(page, url, envelopeHeaderRequestParser);
+
+  expect(envHeader.baggage).toBeDefined();
+  expect(envHeader.baggage).toEqual(
+    'sentry-environment=production,sentry-transaction=testTransactionBaggage,sentry-userid=user123,sentry-usersegment=segmentB',
+  );
+});

packages/integration-tests/utils/helpers.ts

@@ -1,5 +1,5 @@
 import { Page, Request } from '@playwright/test';
-import { Event } from '@sentry/types';
+import { Event, EventEnvelopeHeaders } from '@sentry/types';
 
 const envelopeUrlRegex = /\.sentry\.io\/api\/\d+\/envelope\//;
 
@@ -11,6 +11,14 @@ const envelopeRequestParser = (request: Request | null): Event => {
   return envelope.split('\n').map(line => JSON.parse(line))[2];
 };
 
+export const envelopeHeaderRequestParser = (request: Request | null): EventEnvelopeHeaders => {
+  // https://develop.sentry.dev/sdk/envelopes/
+  const envelope = request?.postData() || '';
+
+  // First row of the envelop is the event payload.
+  return envelope.split('\n').map(line => JSON.parse(line))[0];
+};
+
 /**
  * Run script at the given path inside the test environment.
  *
@@ -122,10 +130,11 @@ async function getMultipleSentryEnvelopeRequests<T>(
     url?: string;
     timeout?: number;
   },
+  requestParser: (req: Request) => T = envelopeRequestParser as (req: Request) => T,
 ): Promise<T[]> {
   // TODO: This is not currently checking the type of envelope, just casting for now.
   // We can update this to include optional type-guarding when we have types for Envelope.
-  return getMultipleRequests(page, count, envelopeUrlRegex, envelopeRequestParser, options) as Promise<T[]>;
+  return getMultipleRequests(page, count, envelopeUrlRegex, requestParser, options) as Promise<T[]>;
 }
 
 /**
@@ -136,8 +145,12 @@ async function getMultipleSentryEnvelopeRequests<T>(
  * @param {string} [url]
  * @return {*}  {Promise<T>}
  */
-async function getFirstSentryEnvelopeRequest<T>(page: Page, url?: string): Promise<T> {
-  return (await getMultipleSentryEnvelopeRequests<T>(page, 1, { url }))[0];
+async function getFirstSentryEnvelopeRequest<T>(
+  page: Page,
+  url?: string,
+  requestParser: (req: Request) => T = envelopeRequestParser as (req: Request) => T,
+): Promise<T> {
+  return (await getMultipleSentryEnvelopeRequests<T>(page, 1, { url }, requestParser))[0];
 }
 
 /**

packages/types/src/envelope.ts

@@ -56,7 +56,7 @@ export type SessionItem =
   | BaseEnvelopeItem<SessionAggregatesItemHeaders, SessionAggregates>;
 export type ClientReportItem = BaseEnvelopeItem<ClientReportItemHeaders, ClientReport>;
 
-type EventEnvelopeHeaders = { event_id: string; sent_at: string };
+export type EventEnvelopeHeaders = { event_id: string; sent_at: string; baggage?: string };
 type SessionEnvelopeHeaders = { sent_at: string };
 type ClientReportEnvelopeHeaders = BaseEnvelopeHeaders;
 

packages/types/src/index.ts

@@ -15,6 +15,7 @@ export type {
   EnvelopeItemType,
   EnvelopeItem,
   EventEnvelope,
+  EventEnvelopeHeaders,
   EventItem,
   SessionEnvelope,
   SessionItem,

packages/utils/src/baggage.ts

@@ -1,7 +1,7 @@
 import { IS_DEBUG_BUILD } from './flags';
 import { logger } from './logger';
 
-export type AllowedBaggageKeys = 'environment' | 'release'; // TODO: Add remaining allowed baggage keys | 'transaction' | 'userid' | 'usersegment';
+export type AllowedBaggageKeys = 'environment' | 'release' | 'userid' | 'transaction' | 'usersegment';
 export type BaggageObj = Partial<Record<AllowedBaggageKeys, string> & Record<string, string>>;
 
 /**
@@ -47,6 +47,11 @@ export function setBaggageValue(baggage: Baggage, key: keyof BaggageObj, value:
   baggage[0][key] = value;
 }
 
+/** Check if the baggage object (i.e. the first element in the tuple) is empty */
+export function isBaggageEmpty(baggage: Baggage): boolean {
+  return Object.keys(baggage[0]).length === 0;
+}
+
 /** Serialize a baggage object */
 export function serializeBaggage(baggage: Baggage): string {
   return Object.keys(baggage[0]).reduce((prev, key: keyof BaggageObj) => {

packages/utils/src/index.ts

@@ -23,3 +23,4 @@ export * from './env';
 export * from './envelope';
 export * from './clientreport';
 export * from './ratelimit';
+export * from './baggage';