get-cloud-region

packages/synthetics-sdk-api/package.json

@@ -43,7 +43,8 @@
     "error-stack-parser": "2.1.4",
     "google-auth-library": "9.0.0",
     "ts-proto": "1.148.1",
-    "winston": "3.10.0"
+    "winston": "3.10.0",
+    "axios": "1.6.7"
   },
   "author": "Google Inc.",
   "license": "Apache-2.0"

packages/synthetics-sdk-api/src/cloud_region_resolver.ts

@@ -0,0 +1,48 @@
+// Copyright 2023 Google LLC
+//
+// 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 axios, { AxiosResponse } from 'axios';
+
+/**
+ *
+ * @public
+ *
+ * Retrieves the region in which the current Google Cloud Function (v2) is
+ * executing by querying the metadata server.
+ */
+export async function getExecutionRegion(): Promise<string | null> {
+  const metadataServerUrl =
+    'http://metadata.google.internal/computeMetadata/v1/instance/region';
+  const headers = { 'Metadata-Flavor': 'Google' };
+
+  try {
+    const response: AxiosResponse = await axios.get(metadataServerUrl, {
+      headers,
+    });
+
+    // Extract region from the response (e.g., 'us-east1')
+    const regions = response.data.split('/');
+    const region = regions[regions.length - 1];
+
+    return region;
+  } catch (error) {
+    if (axios.isAxiosError(error)) {
+      console.error('Error fetching region from metadata server:', error);
+    } else {
+      console.error('Unexpected error:', error);
+    }
+  }
+
+  return null;
+}

packages/synthetics-sdk-api/src/index.ts

@@ -26,3 +26,4 @@ export {
   instantiateAutoInstrumentation,
   getInstrumentedLogger,
 } from './auto_instrumentation';
+export { getExecutionRegion } from './cloud_region_resolver';

packages/synthetics-sdk-api/test/unit/cloud_region_resolver.spec.ts

@@ -0,0 +1,45 @@
+// Copyright 2023 Google LLC
+//
+// 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 axios from 'axios';
+import * as sinon from 'sinon';
+import { expect } from 'chai';
+import { getExecutionRegion } from '../../src/cloud_region_resolver';
+
+describe('getExecutionRegion', () => {
+  let axiosGetStub: sinon.SinonStub;
+
+  beforeEach(() => {
+    axiosGetStub = sinon.stub(axios, 'get');
+  });
+
+  afterEach(() => {
+    axiosGetStub.restore();
+  });
+
+  it('should retrieve the region from the metadata server', async () => {
+    axiosGetStub.resolves({ data: 'projects/123456789/regions/us-east1' });
+
+    const region = await getExecutionRegion();
+    expect(region).to.equal('us-east1');
+    expect(axiosGetStub.calledOnce).to.be.true;
+  });
+
+  it('should handle errors from the metadata server', async () => {
+    axiosGetStub.rejects(new Error('Metadata server error'));
+
+    const region = await getExecutionRegion();
+    expect(region).to.be.null;
+  });
+});