fix(bff): filter app configuration telemetry spans (#3788)

Author: arealmaas

packages/bff/src/instrumentation.ts

@@ -21,17 +21,12 @@ import {
 } from '@opentelemetry/sdk-trace-base';
 import { ATTR_SERVICE_NAME, SEMRESATTRS_SERVICE_INSTANCE_ID } from '@opentelemetry/semantic-conventions';
 import config from './config.ts';
+import { filterAppConfigSpans, filterGraphQLSpans } from './instrumentationFilters.ts';
 
 const { openTelemetry } = config;
-const spansExcludedFromExport = new Set([
-  'graphql.parse',
-  'graphql.validate',
-  'graphql.parseSchema',
-  'graphql.validateSchema',
-]);
-
-const shouldDropSpanByName = (spanName: string): boolean => {
-  return spansExcludedFromExport.has(spanName);
+
+const shouldDropSpan = (span: ReadableSpan): boolean => {
+  return filterGraphQLSpans(span.name) || filterAppConfigSpans(span.attributes);
 };
 
 // Configure HTTP instrumentation with filtering
@@ -48,13 +43,6 @@ const httpInstrumentationConfig: HttpInstrumentationConfig = {
     }
     return false;
   },
-  ignoreOutgoingRequestHook: (request) => {
-    // Ignore outgoing requests to Azure App Configuration
-    if ((request.hostname ?? request.host)?.includes('appconfiguration.azconfig.io')) {
-      return true;
-    }
-    return false;
-  },
 };
 
 // Configure instrumentations
@@ -84,7 +72,7 @@ class SpanNameFilteringProcessor implements SpanProcessor {
   }
 
   onEnd(span: ReadableSpan): void {
-    if (shouldDropSpanByName(span.name)) {
+    if (shouldDropSpan(span)) {
       return;
     }
     this.delegate.onEnd(span);

packages/bff/src/instrumentationFilters.ts

@@ -0,0 +1,20 @@
+const appConfigurationHostIdentifier = 'appconfiguration.azconfig.io';
+const graphqlSpansExcludedFromExport = new Set([
+  'graphql.parse',
+  'graphql.validate',
+  'graphql.parseSchema',
+  'graphql.validateSchema',
+]);
+
+export const filterGraphQLSpans = (spanName: string): boolean => {
+  return graphqlSpansExcludedFromExport.has(spanName);
+};
+
+export const filterAppConfigSpans = (attributes: Record<string, unknown>): boolean => {
+  const httpHost = attributes['http.host'];
+  if (typeof httpHost !== 'string') {
+    return false;
+  }
+
+  return httpHost.toLowerCase().includes(appConfigurationHostIdentifier);
+};

packages/bff/tests/instrumentationFilters.spec.ts

@@ -0,0 +1,41 @@
+import { describe, expect, it } from 'vitest';
+import { filterAppConfigSpans, filterGraphQLSpans } from '../src/instrumentationFilters.ts';
+
+describe('filterGraphQLSpans', () => {
+  it('returns true for internal GraphQL parse and validation spans', () => {
+    expect(filterGraphQLSpans('graphql.parse')).toBe(true);
+    expect(filterGraphQLSpans('graphql.validate')).toBe(true);
+    expect(filterGraphQLSpans('graphql.parseSchema')).toBe(true);
+    expect(filterGraphQLSpans('graphql.validateSchema')).toBe(true);
+  });
+
+  it('returns false for other span names', () => {
+    expect(filterGraphQLSpans('http GET')).toBe(false);
+  });
+});
+
+describe('filterAppConfigSpans', () => {
+  it('returns true for spans with app configuration host attributes', () => {
+    expect(
+      filterAppConfigSpans({
+        'http.host': 'dp-fe-staging-appconfiguration.azconfig.io:443',
+      }),
+    ).toBe(true);
+  });
+
+  it('returns false when http.host is missing', () => {
+    expect(
+      filterAppConfigSpans({
+        'http.url': 'https://dp-fe-staging-appconfiguration.azconfig.io/kv?api-version=2023-11-01',
+      }),
+    ).toBe(false);
+  });
+
+  it('returns false for spans without app configuration host attributes', () => {
+    expect(
+      filterAppConfigSpans({
+        'http.host': 'example.com',
+      }),
+    ).toBe(false);
+  });
+});