feat(auto-instrumentations-node): disabling instrumentations via env var (#2174)

* feat(auto-instr-node): disabling instrumentations via env var

* create new func to reduce code duplication

* fix Object is possibly undefined

---------

Co-authored-by: Amir Blum <[email protected]>

Author: JamieDanielson

metapackages/auto-instrumentations-node/README.md

@@ -77,8 +77,9 @@ For example, to enable only the `env`, `host` detectors:
 export OTEL_NODE_RESOURCE_DETECTORS="env,host"
 ```
 
-By default, all [Supported Instrumentations](#supported-instrumentations) are enabled,
-but you can use the environment variable `OTEL_NODE_ENABLED_INSTRUMENTATIONS` to enable only certain instrumentations
+By default, all [Supported Instrumentations](#supported-instrumentations) are enabled.
+You can use the environment variable `OTEL_NODE_ENABLED_INSTRUMENTATIONS` to enable only certain instrumentations,
+OR the environment variable `OTEL_NODE_DISABLED_INSTRUMENTATIONS` to disable only certain instrumentations,
 by providing a comma-separated list of the instrumentation package names without the `@opentelemetry/instrumentation-` prefix.
 
 For example, to enable only
@@ -90,6 +91,12 @@ instrumentations:
 export OTEL_NODE_ENABLED_INSTRUMENTATIONS="http,nestjs-core"
 ```
 
+To disable only [@opentelemetry/instrumentation-fs](https://github.com/open-telemetry/opentelemetry-js-contrib/tree/main/plugins/node/instrumentation-fs):
+
+```shell
+export OTEL_NODE_DISABLED_INSTRUMENTATIONS="fs"
+```
+
 To enable logging for troubleshooting, set the log level by setting the `OTEL_LOG_LEVEL` environment variable to one of the following:
 
 - `none`

metapackages/auto-instrumentations-node/src/utils.ts

@@ -147,6 +147,7 @@ export function getNodeAutoInstrumentations(
 ): Instrumentation[] {
   checkManuallyProvidedInstrumentationNames(Object.keys(inputConfigs));
   const enabledInstrumentationsFromEnv = getEnabledInstrumentationsFromEnv();
+  const disabledInstrumentationsFromEnv = getDisabledInstrumentationsFromEnv();
 
   const instrumentations: Instrumentation[] = [];
 
@@ -159,7 +160,8 @@ export function getNodeAutoInstrumentations(
 
     if (
       userConfig.enabled === false ||
-      !enabledInstrumentationsFromEnv.includes(name)
+      !enabledInstrumentationsFromEnv.includes(name) ||
+      disabledInstrumentationsFromEnv.includes(name)
     ) {
       diag.debug(`Disabling instrumentation for ${name}`);
       continue;
@@ -186,6 +188,22 @@ function checkManuallyProvidedInstrumentationNames(
   }
 }
 
+function getInstrumentationsFromEnv(envVar: string): string[] {
+  const envVarValue = process.env[envVar];
+  if (envVarValue == null) {
+    return [];
+  }
+
+  const instrumentationsFromEnv = envVarValue
+    ?.split(',')
+    .map(
+      instrumentationPkgSuffix =>
+        `@opentelemetry/instrumentation-${instrumentationPkgSuffix.trim()}`
+    );
+  checkManuallyProvidedInstrumentationNames(instrumentationsFromEnv);
+  return instrumentationsFromEnv;
+}
+
 /**
  * Returns the list of instrumentations that are enabled based on the environment variable.
  */
@@ -194,12 +212,23 @@ function getEnabledInstrumentationsFromEnv() {
     return Object.keys(InstrumentationMap);
   }
 
-  const instrumentationsFromEnv =
-    process.env.OTEL_NODE_ENABLED_INSTRUMENTATIONS.split(',').map(
-      instrumentationPkgSuffix =>
-        `@opentelemetry/instrumentation-${instrumentationPkgSuffix.trim()}`
-    );
-  checkManuallyProvidedInstrumentationNames(instrumentationsFromEnv);
+  const instrumentationsFromEnv = getInstrumentationsFromEnv(
+    'OTEL_NODE_ENABLED_INSTRUMENTATIONS'
+  );
+  return instrumentationsFromEnv;
+}
+
+/**
+ * Returns the list of instrumentations that are disabled based on the environment variable.
+ */
+function getDisabledInstrumentationsFromEnv() {
+  if (!process.env.OTEL_NODE_DISABLED_INSTRUMENTATIONS) {
+    return [];
+  }
+
+  const instrumentationsFromEnv = getInstrumentationsFromEnv(
+    'OTEL_NODE_DISABLED_INSTRUMENTATIONS'
+  );
   return instrumentationsFromEnv;
 }
 

metapackages/auto-instrumentations-node/test/utils.test.ts

@@ -89,6 +89,31 @@ describe('utils', () => {
       }
     });
 
+    it('should include all instrumentations except those disabled via OTEL_NODE_DISABLED_INSTRUMENTATIONS environment variable', () => {
+      process.env.OTEL_NODE_DISABLED_INSTRUMENTATIONS =
+        'fs,aws-sdk, aws-lambda'; // separator with and without whitespaces should be allowed
+      try {
+        const instrumentations = getNodeAutoInstrumentations();
+        const disabledInstrumentations = new Set([
+          '@opentelemetry/instrumentation-fs',
+          '@opentelemetry/instrumentation-aws-sdk',
+          '@opentelemetry/instrumentation-aws-lambda',
+        ]);
+        const enabledInstrumentationNames = new Set(
+          instrumentations.map(i => i.instrumentationName)
+        );
+
+        for (const disabledInstrumentation of disabledInstrumentations) {
+          assert.strictEqual(
+            enabledInstrumentationNames.has(disabledInstrumentation),
+            false
+          );
+        }
+      } finally {
+        delete process.env.OTEL_NODE_DISABLED_INSTRUMENTATIONS;
+      }
+    });
+
     it('should show error for none existing instrumentation', () => {
       const spy = sinon.stub(diag, 'error');
       const name = '@opentelemetry/instrumentation-http2';