Use clusterName as service name on GKE (#309)

ofrobots · web-flow · commit 70d8730d13e4 · 2017-07-12T17:31:41.000-07:00
* ability to query GKE cluster name from metadata * use GKE cluster name as the service name Fixes: #280
diff --git a/src/agent/debuglet.ts b/src/agent/debuglet.ts
@@ -262,6 +262,24 @@ export class Debuglet extends EventEmitter {
         return;
       }
 
+      if (onGCP &&
+          (!that.config_.serviceContext ||
+           !that.config_.serviceContext.service)) {
+        // If on GCP, check if the clusterName instance attribute is availble.
+        // Use this as the service context for better service identification on
+        // GKE.
+        try {
+          const clusterName = await Debuglet.getClusterNameFromMetadata();
+          that.config_.serviceContext = {
+            service: clusterName,
+            version: 'unversioned',
+            minorVersion_: null
+          };
+        } catch (err) {
+          /* we are not running on GKE - Ignore error. */
+        }
+      }
+
       that.getSourceContext_(function(err5, sourceContext) {
         if (err5) {
           that.logger_.warn('Unable to discover source context', err5);
@@ -402,6 +420,16 @@ export class Debuglet extends EventEmitter {
     });
   }
 
+  static getClusterNameFromMetadata(): Promise<string> {
+    return new Promise<string>((resolve, reject) => {
+      metadata.instance(
+          'attributes/cluster-name',
+          (err: Error, _res: http.ServerResponse, clusterName: string) => {
+            err ? reject(err) : resolve(clusterName);
+          });
+    });
+  }
+
   getSourceContext_(
       callback:
           (err: Error|string, sourceContext: {[key: string]: string}) => void):
diff --git a/test/test-debuglet.js b/test/test-debuglet.js
@@ -136,6 +136,46 @@ describe('Debuglet', function() {
     });
   });
 
+  describe('getClusterNameFromMetadata', () => {
+    let savedInstance;
+    before(() => {
+      savedInstance = metadata.instance;
+    });
+    after(() => {
+      metadata.instance = savedInstance;
+    });
+
+    it('should return project retrived from metadata', (done) => {
+      const FAKE_CLUSTER_NAME = 'fake-cluster-name-from-metadata';
+      var debug = require('../build/src/debug.js').Debug();
+      var debuglet = new Debuglet(debug, defaultConfig);
+
+      metadata.instance = (path, cb) => {
+        setImmediate(() => { 
+          cb(null, {}, FAKE_CLUSTER_NAME);
+        });
+      }
+
+      Debuglet.getClusterNameFromMetadata().then((clusterName) => {
+        assert.strictEqual(clusterName, FAKE_CLUSTER_NAME);
+        done();
+      });
+    });
+
+    it('should return null on error', (done) => {
+      var debug = require('../build/src/debug.js').Debug();
+      var debuglet = new Debuglet(debug, defaultConfig);
+
+      metadata.instance = (path, cb) => {
+        setImmediate(() => { cb(new Error()); });
+      }
+
+      Debuglet.getClusterNameFromMetadata().catch((err) => {
+        done();
+      });
+    });
+  });
+
   describe('getProjectId', () => {
     let savedGetProjectIdFromMetadata;
 
@@ -502,8 +542,6 @@ describe('Debuglet', function() {
       });
     });
 
-
-
     it('should retry on failed registration', function(done) {
       this.timeout(10000);
       var debug = require('../build/src/debug.js').Debug(
@@ -563,6 +601,37 @@ describe('Debuglet', function() {
       debuglet.start();
     });
 
+    it('should attempt to retrieve cluster name if needed', (done) => {
+      const savedRunningOnGCP = Debuglet.runningOnGCP;
+      Debuglet.runningOnGCP = () => {
+        return Promise.resolve(true);
+      };
+      const clusterScope = 
+          nock('http://metadata.google.internal')
+            .get('/computeMetadata/v1/instance/attributes/cluster-name')
+            .once()
+            .reply(200, 'cluster-name-from-metadata');
+
+      var debug = require('../build/src/debug.js').Debug(
+          {projectId: 'fake-project', credentials: fakeCredentials});
+      var debuglet = new Debuglet(debug, defaultConfig);
+
+      nocks.oauth2();
+      var scope = nock(API)
+                      .post(REGISTER_PATH)
+                      .reply(200, {debuggee: {id: DEBUGGEE_ID}});
+
+      debuglet.once('registered', function(id) {
+        assert.equal(id, DEBUGGEE_ID);
+        debuglet.stop();
+        clusterScope.done();
+        scope.done();
+        Debuglet.runningOnGCP = savedRunningOnGCP;
+        done();
+      });
+
+      debuglet.start();
+    });
 
     it('should pass source context to api if present', function(done) {
       var debug = require('../build/src/debug.js').Debug(
