From b29deeed5029598385aedd30f9b540b1248bea52 Mon Sep 17 00:00:00 2001
From: Osher Vaknin <81672378+osherv@users.noreply.github.com>
Date: Sun, 20 Nov 2022 17:28:26 +0200
Subject: [PATCH] feat(instrumentation): add new setMeterInstruments method
 (#3267)

Co-authored-by: Chengzhong Wu <legendecas@gmail.com>
Fixes https://github.com/open-telemetry/opentelemetry-js/issues/3249
---
 experimental/CHANGELOG.md                     |  1 +
 .../src/http.ts                               | 11 ++------
 .../package.json                              |  1 +
 .../src/instrumentation.ts                    | 10 +++++++
 .../test/common/Instrumentation.test.ts       | 27 ++++++++++++++++++-
 5 files changed, 40 insertions(+), 10 deletions(-)

diff --git a/experimental/CHANGELOG.md b/experimental/CHANGELOG.md
index f0e7bf5ab3..7d39f3e228 100644
--- a/experimental/CHANGELOG.md
+++ b/experimental/CHANGELOG.md
@@ -9,6 +9,7 @@ All notable changes to experimental packages in this project will be documented
 ### :rocket: (Enhancement)
 
 * feat(instrumentation-http): monitor error events with events.errorMonitor [#3402](https://github.com/open-telemetry/opentelemetry-js/pull/3402) @legendecas
+* feat(instrumentation): add new `_setMeterInstruments` protected method that update the meter instruments every meter provider update.
 
 ### :bug: (Bug Fix)
 
diff --git a/experimental/packages/opentelemetry-instrumentation-http/src/http.ts b/experimental/packages/opentelemetry-instrumentation-http/src/http.ts
index 71f3363f2d..0f19ffd867 100644
--- a/experimental/packages/opentelemetry-instrumentation-http/src/http.ts
+++ b/experimental/packages/opentelemetry-instrumentation-http/src/http.ts
@@ -26,9 +26,8 @@ import {
   SpanStatusCode,
   trace,
   Histogram,
-  MeterProvider,
   MetricAttributes,
-  ValueType,
+  ValueType
 } from '@opentelemetry/api';
 import { hrTime, hrTimeDuration, hrTimeToMilliseconds, suppressTracing } from '@opentelemetry/core';
 import type * as http from 'http';
@@ -74,15 +73,9 @@ export class HttpInstrumentation extends InstrumentationBase<Http> {
       config
     );
     this._headerCapture = this._createHeaderCapture();
-    this._updateMetricInstruments();
   }
 
-  override setMeterProvider(meterProvider: MeterProvider) {
-    super.setMeterProvider(meterProvider);
-    this._updateMetricInstruments();
-  }
-
-  private _updateMetricInstruments() {
+  protected override _updateMetricInstruments() {
     this._httpServerDurationHistogram = this.meter.createHistogram('http.server.duration', {
       description: 'measures the duration of the inbound HTTP requests',
       unit: 'ms',
diff --git a/experimental/packages/opentelemetry-instrumentation/package.json b/experimental/packages/opentelemetry-instrumentation/package.json
index 29b186d510..8dc3dfb9d2 100644
--- a/experimental/packages/opentelemetry-instrumentation/package.json
+++ b/experimental/packages/opentelemetry-instrumentation/package.json
@@ -76,6 +76,7 @@
     "@opentelemetry/api": "^1.3.0"
   },
   "devDependencies": {
+    "@opentelemetry/sdk-metrics": "^1.8.0",
     "@babel/core": "7.16.0",
     "@opentelemetry/api": "^1.3.0",
     "@types/mocha": "10.0.0",
diff --git a/experimental/packages/opentelemetry-instrumentation/src/instrumentation.ts b/experimental/packages/opentelemetry-instrumentation/src/instrumentation.ts
index 5024b5d536..d562ed9056 100644
--- a/experimental/packages/opentelemetry-instrumentation/src/instrumentation.ts
+++ b/experimental/packages/opentelemetry-instrumentation/src/instrumentation.ts
@@ -56,6 +56,7 @@ implements types.Instrumentation {
     this._tracer = trace.getTracer(instrumentationName, instrumentationVersion);
 
     this._meter = metrics.getMeter(instrumentationName, instrumentationVersion);
+    this._updateMetricInstruments();
   }
 
   /* Api to wrap instrumented method */
@@ -81,6 +82,15 @@ implements types.Instrumentation {
       this.instrumentationName,
       this.instrumentationVersion
     );
+
+    this._updateMetricInstruments();
+  }
+
+  /**
+   * Sets the new metric instruments with the current Meter.
+   */
+  protected _updateMetricInstruments(): void {
+    return;
   }
 
   /* Returns InstrumentationConfig */
diff --git a/experimental/packages/opentelemetry-instrumentation/test/common/Instrumentation.test.ts b/experimental/packages/opentelemetry-instrumentation/test/common/Instrumentation.test.ts
index ac0c5b0a90..be53d1ca59 100644
--- a/experimental/packages/opentelemetry-instrumentation/test/common/Instrumentation.test.ts
+++ b/experimental/packages/opentelemetry-instrumentation/test/common/Instrumentation.test.ts
@@ -21,6 +21,8 @@ import {
   InstrumentationConfig,
 } from '../../src';
 
+import { MeterProvider } from '@opentelemetry/sdk-metrics';
+
 interface TestInstrumentationConfig extends InstrumentationConfig {
   isActive?: boolean;
 }
@@ -54,13 +56,36 @@ describe('BaseInstrumentation', () => {
 
   describe('constructor', () => {
     it('should enable instrumentation by default', () => {
-      let called = false;
+      let enableCalled = false;
+      let updateMetricInstrumentsCalled = false;
       class TestInstrumentation2 extends TestInstrumentation {
         override enable() {
+          enableCalled = true;
+        }
+        override _updateMetricInstruments() {
+          updateMetricInstrumentsCalled = true;
+        }
+      }
+      instrumentation = new TestInstrumentation2();
+      assert.strictEqual(enableCalled, true);
+      assert.strictEqual(updateMetricInstrumentsCalled, true);
+    });
+  });
+
+  describe('setMeterProvider', () => {
+    let otelTestingMeterProvider: MeterProvider;
+    beforeEach(() => {
+      otelTestingMeterProvider = new MeterProvider();
+    });
+    it('should call _updateMetricInstruments', () => {
+      let called = true;
+      class TestInstrumentation2 extends TestInstrumentation {
+        override _updateMetricInstruments() {
           called = true;
         }
       }
       instrumentation = new TestInstrumentation2();
+      instrumentation.setMeterProvider(otelTestingMeterProvider);
       assert.strictEqual(called, true);
     });
   });