feat: implement HostDetector (#2921)

Co-authored-by: Valentin Marchaud <contact@vmarchaud.fr>

CHANGELOG.md

@@ -10,6 +10,7 @@ All notable changes to this project will be documented in this file.
 
 * feat(ConsoleSpanExporter): export span links [#2917](https://github.com/open-telemetry/opentelemetry-js/pull/2917) @trentm
 * feat: warn when hooked module is already loaded [#2926](https://github.com/open-telemetry/opentelemetry-js/pull/2926) @nozik
+* feat: implement HostDetector [#2921](https://github.com/open-telemetry/opentelemetry-js/pull/2921) @rauno56
 
 ### :bug: (Bug Fix)
 

packages/opentelemetry-resources/src/detectors/HostDetector.ts

@@ -0,0 +1,52 @@
+/*
+ * 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 { SemanticResourceAttributes } from '@opentelemetry/semantic-conventions';
+import { Resource } from '../Resource';
+import { Detector, ResourceAttributes } from '../types';
+import { ResourceDetectionConfig } from '../config';
+import { arch, hostname } from 'os';
+
+/**
+ * HostDetector detects the resources related to the host current process is
+ * running on. Currently only non-cloud-based attributes are included.
+ */
+class HostDetector implements Detector {
+  async detect(_config?: ResourceDetectionConfig): Promise<Resource> {
+    const attributes: ResourceAttributes = {
+      [SemanticResourceAttributes.HOST_NAME]: hostname(),
+      [SemanticResourceAttributes.HOST_ARCH]: this._normalizeArch(arch()),
+    };
+    return new Resource(attributes);
+  }
+
+  private _normalizeArch(nodeArchString: string): string {
+    // Maps from https://nodejs.org/api/os.html#osarch to arch values in spec:
+    // https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/resource/semantic_conventions/host.md
+    switch (nodeArchString) {
+      case 'arm':
+        return 'arm32';
+      case 'ppc':
+        return 'ppc32';
+      case 'x64':
+        return 'amd64';
+      default:
+        return nodeArchString;
+    }
+  }
+}
+
+export const hostDetector = new HostDetector();

packages/opentelemetry-resources/src/detectors/index.ts

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+export * from './BrowserDetector';
 export * from './EnvDetector';
+export * from './HostDetector';
 export * from './ProcessDetector';
-export * from './BrowserDetector';

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

@@ -0,0 +1,58 @@
+/*
+ * 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 * as sinon from 'sinon';
+import * as assert from 'assert';
+import { SemanticResourceAttributes } from '@opentelemetry/semantic-conventions';
+import { describeNode } from '../../util';
+import { hostDetector, Resource } from '../../../src';
+
+describeNode('hostDetector() on Node.js', () => {
+  afterEach(() => {
+    sinon.restore();
+  });
+
+  it('should return resource information about the host', async () => {
+    const os = require('os');
+
+    sinon.stub(os, 'arch').returns('x64');
+    sinon.stub(os, 'hostname').returns('opentelemetry-test');
+
+    const resource: Resource = await hostDetector.detect();
+
+    assert.strictEqual(
+      resource.attributes[SemanticResourceAttributes.HOST_NAME],
+      'opentelemetry-test'
+    );
+    assert.strictEqual(
+      resource.attributes[SemanticResourceAttributes.HOST_ARCH],
+      'amd64'
+    );
+  });
+
+  it('should pass through arch string if unknown', async () => {
+    const os = require('os');
+
+    sinon.stub(os, 'arch').returns('some-unknown-arch');
+
+    const resource: Resource = await hostDetector.detect();
+
+    assert.strictEqual(
+      resource.attributes[SemanticResourceAttributes.HOST_ARCH],
+      'some-unknown-arch'
+    );
+  });
+});