fix: add extra logging for incorrect headers (#637)

* fix: add extra logging for incorrect headers * fix header * respond to comments * Update src/index.ts Co-authored-by: d-goog <[email protected]> * Update test/index.test.ts Co-authored-by: d-goog <[email protected]> * Update test/index.test.ts Co-authored-by: d-goog <[email protected]> * Update index.ts --------- Co-authored-by: d-goog <[email protected]>
googleapis · Jan 30, 2025 · edafa87 · edafa87
1 parent bd79ae1
commit edafa87
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Showing 4 changed files with 59 additions and 4 deletions.
diff --git a/.gitignore b/.gitignore
@@ -8,4 +8,5 @@ package-lock.json
 gcp-metadata.tgz
 docs/
 __pycache__
-.DS_Store
+.DS_Store
+*.tgz
diff --git a/package.json b/package.json
@@ -38,6 +38,7 @@
   "license": "Apache-2.0",
   "dependencies": {
     "gaxios": "^6.1.1",
+    "google-logging-utils": "^0.0.2",
     "json-bigint": "^1.0.0"
   },
   "devDependencies": {

diff --git a/src/index.ts b/src/index.ts
@@ -18,6 +18,7 @@ import {GaxiosError, GaxiosOptions, GaxiosResponse, request} from 'gaxios';
 import {OutgoingHttpHeaders} from 'http';
 import jsonBigint = require('json-bigint');
 import {detectGCPResidency} from './gcp-residency';
+import * as logger from 'google-logging-utils';
 
 export const BASE_PATH = '/computeMetadata/v1';
 export const HOST_ADDRESS = 'http://169.254.169.254';
@@ -27,6 +28,8 @@ export const HEADER_NAME = 'Metadata-Flavor';
 export const HEADER_VALUE = 'Google';
 export const HEADERS = Object.freeze({[HEADER_NAME]: HEADER_VALUE});
 
+const log = logger.log('gcp metadata');
+
 /**
  * Metadata server detection override options.
  *
@@ -151,18 +154,22 @@ async function metadataAccessor<T>(
   }
 
   const requestMethod = fastFail ? fastFailMetadataRequest : request;
-  const res = await requestMethod<T>({
+  const req: GaxiosOptions = {
     url: `${getBaseUrl()}/${metadataKey}`,
     headers: {...HEADERS, ...headers},
     retryConfig: {noResponseRetries},
     params,
     responseType: 'text',
     timeout: requestTimeout(),
-  });
+  } as GaxiosOptions;
+  log.info('instance request %j', req);
+
+  const res = await requestMethod<T>(req);
+  log.info('instance metadata is %s', res.data);
   // NOTE: node.js converts all incoming headers to lower case.
   if (res.headers[HEADER_NAME.toLowerCase()] !== HEADER_VALUE) {
     throw new Error(
-      `Invalid response from metadata service: incorrect ${HEADER_NAME} header.`
+      `Invalid response from metadata service: incorrect ${HEADER_NAME} header. Expected '${HEADER_VALUE}', got ${res.headers[HEADER_NAME.toLowerCase()] ? `'${res.headers[HEADER_NAME.toLowerCase()]}'` : 'no header'}`,
     );
   }
 

diff --git a/test/index.test.ts b/test/index.test.ts
@@ -117,6 +117,52 @@ describe('unit test', () => {
     scope.done();
   });
 
+  it('should throw a valuable error when headers do not match', async () => {
+    const scope = nock(HOST)
+      .get(`${PATH}/${TYPE}/${PROPERTY}`)
+      .reply(
+        200,
+        {},
+        {
+          [gcp.HEADER_NAME.toLowerCase()]: 'wrongHeader',
+        },
+      );
+
+    await assert.rejects(
+      async () => {
+        await gcp.instance({property: PROPERTY});
+      },
+      err => {
+        assert(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          "Invalid response from metadata service: incorrect Metadata-Flavor header. Expected 'Google', got 'wrongHeader'",
+        );
+        scope.done();
+        return true;
+      },
+    );
+  });
+
+  it('should throw a valuable error when header does not exist', async () => {
+    const scope = nock(HOST).get(`${PATH}/${TYPE}/${PROPERTY}`).reply(200, {});
+
+    await assert.rejects(
+      async () => {
+        await gcp.instance({property: PROPERTY});
+      },
+      err => {
+        assert(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          "Invalid response from metadata service: incorrect Metadata-Flavor header. Expected 'Google', got no header",
+        );
+        scope.done();
+        return true;
+      },
+    );
+  });
+
   it('should return large numbers as BigNumber values', async () => {
     const BIG_NUMBER_STRING = '3279739563200103600';
     const scope = nock(HOST)