chore: Add guardrail for OTEL bridge (#3283)

Author: jsumners-nr

index.js

@@ -26,6 +26,10 @@ logger.info(
   pkgJSON.version,
   process.version
 )
+const path = require('node:path')
+const Module = require('node:module')
+const otelPackages = Object.keys(pkgJSON.dependencies).filter(d => d.startsWith('@opentelemetry'))
+const otelRequire = Module.createRequire(path.join(__dirname, __filename))
 
 if (require.cache.__NR_cache) {
   logger.warn(
@@ -48,6 +52,7 @@ function initApi({ agent }) {
   return api
 }
 
+// eslint-disable-next-line sonarjs/cognitive-complexity
 function initialize() {
   logger.debug('Loading agent from %s', __dirname)
   let agent = null
@@ -97,6 +102,10 @@ function initialize() {
       logger.warn(
         'New Relic for Node.js in worker_threads is not officially supported. Not starting! To bypass this, set `config.worker_threads.enabled` to true in configuration.'
       )
+    } else if (config.opentelemetry_bridge.enabled === true && otelBridgeAvailable() === false) {
+      logger.warn(
+        'OpenTelemetry bridge enabled, but packages are missing. Not starting!'
+      )
     } else {
       if (!isMainThread && config.worker_threads.enabled) {
         logger.warn(
@@ -278,3 +287,16 @@ function recordDisabledPackages(agent) {
     }
   }
 }
+
+function otelBridgeAvailable() {
+  for (const p of otelPackages) {
+    try {
+      otelRequire.resolve(p)
+    } catch (error) {
+      if (error.code === 'ERR_MODULE_NOT_FOUND') {
+        return false
+      }
+    }
+  }
+  return true
+}

test/unit/index.test.js

@@ -184,7 +184,8 @@ test('index tests', async (t) => {
       logging: {},
       feature_flag: { flag_1: true, flag_2: false },
       security: { agent: { enabled: false } },
-      worker_threads: { enabled: false }
+      worker_threads: { enabled: false },
+      opentelemetry_bridge: { enabled: false }
     }
     const configMock = {
       getOrCreateInstance: sandbox.stub().returns(mockConfig)

test/unit/otel-bridge.test.js

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2025 New Relic Corporation. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+'use strict'
+
+// The purpose of this test is to verify that the agent will refuse to start
+// when any required Open Telemetry packages are not available and the bridge
+// is supposed to be enabled. The idea being, we can remove the OTEL packages
+// and start the agent with the bridge disabled in order to trim the size of
+// AWS Lambda Layers.
+
+const test = require('node:test')
+const assert = require('node:assert')
+const Module = require('node:module')
+const proxyquire = require('proxyquire')
+
+test('logs warning when missing otel packages', () => {
+  process.env.NEW_RELIC_OPENTELEMETRY_BRIDGE_ENABLED = true
+
+  require.resolve = function resolve (...args) {
+    if (args[0].startsWith('@opentelemetry') === true) {
+      const error = Error('boom')
+      error.code = 'ERR_MODULE_NOT_FOUND'
+      throw error
+    }
+    return require.resolve.apply(require, args)
+  }
+  Module.createRequire = function () {
+    return require
+  }
+
+  const logs = []
+  const agent = proxyquire('../../index.js', {
+    './lib/logger': {
+      info() {},
+      debug() {},
+      warn(...args) {
+        logs.push(args)
+      }
+    }
+  })
+  assert.ok(agent)
+  agent.shutdown()
+  assert.deepEqual(logs, [['OpenTelemetry bridge enabled, but packages are missing. Not starting!']])
+})