chore: reduce bundle size by removing auto-instrumentation from otel (#54)

Author: hugodutka

packages/blink/src/agent/otel.ts

@@ -1,17 +1,20 @@
 import { trace } from "@opentelemetry/api";
-import { getNodeAutoInstrumentations } from "@opentelemetry/auto-instrumentations-node";
 import { OTLPTraceExporter as OTLPHttpTraceExporter } from "@opentelemetry/exporter-trace-otlp-http";
-import { NodeSDK } from "@opentelemetry/sdk-node";
+import { registerInstrumentations } from "@opentelemetry/instrumentation";
+import { UndiciInstrumentation } from "@opentelemetry/instrumentation-undici";
+import { resourceFromAttributes } from "@opentelemetry/resources";
 import {
  BatchSpanProcessor,
  type ReadableSpan,
  type SpanProcessor,
 } from "@opentelemetry/sdk-trace-base";
+import { NodeTracerProvider } from "@opentelemetry/sdk-trace-node";
+import { ATTR_SERVICE_NAME } from "@opentelemetry/semantic-conventions";
 import type { MiddlewareHandler } from "hono";
-import util from "util";
+import util from "node:util";
 import { APIServerURLEnvironmentVariable } from "./constants";
 
-let otelSDK: NodeSDK | undefined;
+let otelProvider: NodeTracerProvider | undefined;
 let consolePatched = false;
 
 function isPlainRecord(val: unknown): val is Record<string | number, unknown> {
@@ -110,14 +113,17 @@ class FilteringSpanProcessor implements SpanProcessor {
  }
 }
 
-// Build the provider (global)
-export function initOtel(): NodeSDK {
- if (otelSDK) {
- return otelSDK;
+export function initOtel(): NodeTracerProvider {
+ if (otelProvider) {
+ return otelProvider;
  }
  patchGlobalConsole();
+
  const apiUrl = process.env[APIServerURLEnvironmentVariable];
- otelSDK = new NodeSDK({
+ const provider = new NodeTracerProvider({
+ resource: resourceFromAttributes({
+ [ATTR_SERVICE_NAME]: "blink.agent",
+ }),
  spanProcessors: apiUrl
  ? [
  new FilteringSpanProcessor(
@@ -129,7 +135,7 @@ export function initOtel(): NodeSDK {
  })
  ),
  (span) => {
- // getNodeAutoInstrumentations creates an HTTP instrumentation that logs spans
+ // UndiciInstrumentation creates an HTTP instrumentation that logs spans
  // for all outgoing HTTP requests, including the ones emitted by the trace exporter itself.
  // This creates an endless loop - we export a span, we emit a span for that export,
  // we export the second span, then we emit a span for that export, etc.
@@ -144,20 +150,23 @@ export function initOtel(): NodeSDK {
  ),
  ]
  : [],
+ });
+
+ provider.register();
+
+ registerInstrumentations({
  instrumentations: [
- getNodeAutoInstrumentations({
- "@opentelemetry/instrumentation-undici": {
- // our runtime wrappers make some internal requests to the agent
- // that are detached from any other spans. we ignore such requests
- // to avoid noise.
- requireParentforSpans: true,
- },
+ new UndiciInstrumentation({
+ // our runtime wrappers make some internal requests to the agent
+ // that are detached from any other spans. we ignore such requests
+ // to avoid noise.
+ requireParentforSpans: true,
  }),
  ],
  });
- otelSDK.start();
 
- return otelSDK;
+ otelProvider = provider;
+ return provider;
 }
 
 export const otelMiddleware: MiddlewareHandler = async (c, next) => {
@@ -189,14 +198,10 @@ export const otelMiddleware: MiddlewareHandler = async (c, next) => {
 
 export const flushOtel = async () => {
  try {
- if (!otelSDK) {
- return;
- }
- const provider = otelSDK["_tracerProvider"];
- if (!(provider && provider.forceFlush)) {
+ if (!otelProvider) {
  return;
  }
- await provider.forceFlush();
+ await otelProvider.forceFlush();
  } catch (err) {
  console.warn("Error flushing OpenTelemetry", err);
  }