fix(opentelemetry-sdk-node): the custom value from env variable for service.instance.id should take priority over random uuid as backup

CHANGELOG.md

@@ -16,6 +16,8 @@ For notes on migrating to 2.x / 0.200.x see [the upgrade guide](doc/upgrade-to-2
 
 ### :bug: Bug Fixes
 
+* fix(opentelemetry-resources): the custom value from env variable for service.instance.id should take priority over random uuid as backup [#6345](https://github.com/open-telemetry/opentelemetry-js/pull/6345) @maryliag
+
 ### :books: Documentation
 
 ### :house: Internal

experimental/packages/opentelemetry-sdk-node/test/sdk.test.ts

@@ -998,6 +998,30 @@ describe('Node SDK', () => {
       assertServiceInstanceIdIsUUID(resource);
       await sdk.shutdown();
     });
+
+    it('should configure service instance id with service instance id from env variable taking priority over random UUID', async () => {
+      process.env.OTEL_RESOURCE_ATTRIBUTES =
+        'service.instance.id=custom-service,service.name=my-service';
+      const sdk = new NodeSDK({
+        autoDetectResources: true,
+        resourceDetectors: [
+          processDetector,
+          envDetector,
+          hostDetector,
+          serviceInstanceIdDetector,
+        ],
+      });
+
+      sdk.start();
+      const resource = sdk['_resource'];
+      await resource.waitForAsyncAttributes?.();
+
+      assertServiceResource(resource, {
+        name: 'my-service',
+        instanceId: 'custom-service',
+      });
+      await sdk.shutdown();
+    });
   });
 
   describe('A disabled SDK should be no-op', () => {

packages/opentelemetry-resources/src/detectors/platform/node/ServiceInstanceIdDetector.ts

@@ -18,15 +18,32 @@ import { ATTR_SERVICE_INSTANCE_ID } from '../../../semconv';
 import { randomUUID } from 'crypto';
 import { ResourceDetectionConfig } from '../../../config';
 import { DetectedResource, ResourceDetector } from '../../../types';
+import { getStringFromEnv, getStringListFromEnv } from '@opentelemetry/core';
 
 /**
  * ServiceInstanceIdDetector detects the resources related to the service instance ID.
  */
 class ServiceInstanceIdDetector implements ResourceDetector {
   detect(_config?: ResourceDetectionConfig): DetectedResource {
+    let serviceInstanceID;
+    if (
+      getStringFromEnv('OTEL_RESOURCE_ATTRIBUTES')?.includes(
+        'service.instance.id'
+      )
+    ) {
+      const resources = getStringListFromEnv('OTEL_RESOURCE_ATTRIBUTES') || [];
+      for (const resource of resources) {
+        const [key, value] = resource.split('=');
+        if (key === 'service.instance.id') {
+          serviceInstanceID = value;
+          break;
+        }
+      }
+    }
+
     return {
       attributes: {
-        [ATTR_SERVICE_INSTANCE_ID]: randomUUID(),
+        [ATTR_SERVICE_INSTANCE_ID]: serviceInstanceID ?? randomUUID(),
       },
     };
   }

packages/opentelemetry-resources/test/detectors/node/ServiceInstanceId.test.ts

@@ -0,0 +1,67 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { serviceInstanceIdDetector } from '../../../src';
+import { resourceFromDetectedResource } from '../../../src/ResourceImpl';
+import { ATTR_SERVICE_INSTANCE_ID } from '../../../src/semconv';
+import { describeNode } from '../../util';
+import * as assert from 'assert';
+
+describeNode('serviceInstanceIdDetector on Node.js', () => {
+  afterEach(() => {
+    delete process.env.OTEL_RESOURCE_ATTRIBUTES;
+    delete process.env.OTEL_NODE_RESOURCE_DETECTORS;
+  });
+
+  it('should return custom value from env', async () => {
+    process.env.OTEL_RESOURCE_ATTRIBUTES = 'service.instance.id=custom-service';
+    const resource = resourceFromDetectedResource(
+      serviceInstanceIdDetector.detect()
+    );
+    assert.strictEqual(
+      resource.attributes[ATTR_SERVICE_INSTANCE_ID],
+      'custom-service'
+    );
+  });
+
+  it('should return custom value from env even with resource detector for random', async () => {
+    process.env.OTEL_RESOURCE_ATTRIBUTES = 'service.instance.id=custom-service';
+    process.env.OTEL_NODE_RESOURCE_DETECTORS = 'serviceinstance';
+    const resource = resourceFromDetectedResource(
+      serviceInstanceIdDetector.detect()
+    );
+    assert.strictEqual(
+      resource.attributes[ATTR_SERVICE_INSTANCE_ID],
+      'custom-service'
+    );
+  });
+
+  it('should return random value', async () => {
+    process.env.OTEL_NODE_RESOURCE_DETECTORS = 'serviceinstance';
+    const resource = resourceFromDetectedResource(
+      serviceInstanceIdDetector.detect()
+    );
+
+    const UUID_REGEX =
+      /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
+    assert.equal(
+      UUID_REGEX.test(
+        resource.attributes[ATTR_SERVICE_INSTANCE_ID]?.toString() || ''
+      ),
+      true
+    );
+  });
+});