feat(opentelemetry-instrumentation-http): support adding custom attri…

…butes before a span is started

packages/opentelemetry-instrumentation-http/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@opentelemetry/instrumentation-http",
-  "version": "0.23.0",
+  "version": "0.23.1",
   "description": "OpenTelemetry http/https automatic instrumentation package.",
   "main": "build/src/index.js",
   "types": "build/src/index.d.ts",

packages/opentelemetry-instrumentation-http/src/http.ts

@@ -408,7 +408,8 @@ export class HttpInstrumentation extends InstrumentationBase<Http> {
       const span = instrumentation._startHttpSpan(
         `${component.toLocaleUpperCase()} ${method}`,
         spanOptions,
-        ctx
+        ctx,
+        request
       );
       const rpcMetadata: RPCMetadata = {
         type: RPCType.HTTP,
@@ -538,7 +539,7 @@ export class HttpInstrumentation extends InstrumentationBase<Http> {
       const spanOptions: SpanOptions = {
         kind: SpanKind.CLIENT,
       };
-      const span = instrumentation._startHttpSpan(operationName, spanOptions);
+      const span = instrumentation._startHttpSpan(operationName, spanOptions, undefined, optionsParsed);
 
       const parentContext = context.active();
       const requestContext = trace.setSpan(parentContext, span);
@@ -584,7 +585,8 @@ export class HttpInstrumentation extends InstrumentationBase<Http> {
   private _startHttpSpan(
     name: string,
     options: SpanOptions,
-    ctx = context.active()
+    ctx = context.active(),
+    request: http.IncomingMessage | http.RequestOptions = {}
   ) {
     /*
      * If a parent is required but not present, we use a `NoopSpan` to still
@@ -603,6 +605,9 @@ export class HttpInstrumentation extends InstrumentationBase<Http> {
     } else if (requireParent === true && currentSpan?.spanContext().isRemote) {
       span = currentSpan;
     } else {
+      if (this._getConfig().startSpanHook) {
+        this._callStartSpanHook(options, request);
+      }
       span = this.tracer.startSpan(name, options, ctx);
     }
     this._spanNotEnded.add(span);
@@ -639,4 +644,14 @@ export class HttpInstrumentation extends InstrumentationBase<Http> {
       true
     );
   }
+  private _callStartSpanHook(
+    options: SpanOptions,
+    request: http.RequestOptions | http.IncomingMessage
+  ) {
+    safeExecuteInTheMiddle(
+      () => this._getConfig().startSpanHook!(options, request),
+      () => {},
+      true
+    );
+  }
 }

packages/opentelemetry-instrumentation-http/src/types.ts

@@ -13,7 +13,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import { Span } from '@opentelemetry/api';
+import { 
+  Span,
+  SpanOptions,
+ } from '@opentelemetry/api';
 import type * as http from 'http';
 import type * as https from 'https';
 import {
@@ -22,6 +25,7 @@ import {
   IncomingMessage,
   request,
   ServerResponse,
+  RequestOptions,
 } from 'http';
 import * as url from 'url';
 import { InstrumentationConfig } from '@opentelemetry/instrumentation';
@@ -67,6 +71,10 @@ export interface HttpResponseCustomAttributeFunction {
   (span: Span, response: IncomingMessage | ServerResponse): void;
 }
 
+export interface StartSpanCustomAttributeFunction {
+  (options: SpanOptions, request: IncomingMessage | RequestOptions): void;
+}
+
 /**
  * Options available for the HTTP instrumentation (see [documentation](https://github.com/open-telemetry/opentelemetry-js/tree/main/packages/opentelemetry-instrumentation-http#http-instrumentation-options))
  */
@@ -81,6 +89,8 @@ export interface HttpInstrumentationConfig extends InstrumentationConfig {
   requestHook?: HttpRequestCustomAttributeFunction;
   /** Function for adding custom attributes before response is handled */
   responseHook?: HttpResponseCustomAttributeFunction;
+  /** Function for adding custom attributes before a span is started */
+  startSpanHook?: StartSpanCustomAttributeFunction;
   /** The primary server name of the matched virtual host. */
   serverName?: string;
   /** Require parent to create span for outgoing requests */

packages/opentelemetry-instrumentation-http/src/version.ts

@@ -15,4 +15,4 @@
  */
 
 // this is autogenerated file, see scripts/version-update.js
-export const VERSION = '0.23.0';
+export const VERSION = '0.23.1';

packages/opentelemetry-instrumentation-http/test/functionals/http-enable.test.ts

@@ -18,7 +18,9 @@ import {
   context,
   propagation,
   Span as ISpan,
-  SpanKind, trace,
+  SpanKind, 
+  trace,
+  SpanOptions,
 } from '@opentelemetry/api';
 import { NodeTracerProvider } from '@opentelemetry/node';
 import {
@@ -39,7 +41,7 @@ import { DummyPropagation } from '../utils/DummyPropagation';
 import { httpRequest } from '../utils/httpRequest';
 import { ContextManager } from '@opentelemetry/api';
 import { AsyncHooksContextManager } from '@opentelemetry/context-async-hooks';
-import type { ClientRequest, IncomingMessage, ServerResponse } from 'http';
+import type { ClientRequest, IncomingMessage, ServerResponse, RequestOptions } from 'http';
 import { isWrapped } from '@opentelemetry/instrumentation';
 import { getRPCMetadata, RPCType } from '@opentelemetry/core';
 
@@ -95,6 +97,13 @@ export const responseHookFunction = (
   span.setAttribute('custom response hook attribute', 'response');
 };
 
+export const startSpanHookFunction = (
+  options: SpanOptions, 
+  request: IncomingMessage | RequestOptions
+): void => {
+  options.attributes = Object.assign({},options.attributes,{guid: request.headers?.guid});
+};
+
 describe('HttpInstrumentation', () => {
   let contextManager: ContextManager;
 
@@ -201,6 +210,7 @@ describe('HttpInstrumentation', () => {
           applyCustomAttributesOnSpan: customAttributeFunction,
           requestHook: requestHookFunction,
           responseHook: responseHookFunction,
+          startSpanHook: startSpanHookFunction,
           serverName,
         });
         instrumentation.enable();
@@ -672,7 +682,8 @@ describe('HttpInstrumentation', () => {
 
       it('custom attributes should show up on client and server spans', async () => {
         await httpRequest.get(
-          `${protocol}://${hostname}:${serverPort}${pathname}`
+          `${protocol}://${hostname}:${serverPort}${pathname}`,
+          {headers: {guid: 'user_guid'}}
         );
         const spans = memoryExporter.getFinishedSpans();
         const [incomingSpan, outgoingSpan] = spans;
@@ -685,6 +696,14 @@ describe('HttpInstrumentation', () => {
           incomingSpan.attributes['custom response hook attribute'],
           'response'
         );
+        assert.strictEqual(
+          incomingSpan.attributes['custom response hook attribute'],
+          'response'
+        );
+        assert.strictEqual(
+          incomingSpan.attributes['guid'],
+          'user_guid'
+        );
         assert.strictEqual(
           incomingSpan.attributes['span kind'],
           SpanKind.CLIENT
@@ -698,6 +717,10 @@ describe('HttpInstrumentation', () => {
           outgoingSpan.attributes['custom response hook attribute'],
           'response'
         );
+        assert.strictEqual(
+          outgoingSpan.attributes['guid'],
+          'user_guid'
+        );
         assert.strictEqual(
           outgoingSpan.attributes['span kind'],
           SpanKind.CLIENT