feat: add auto-inferred platform label (#886)

Author: jamohile

src/agent/debuglet.ts

@@ -68,6 +68,17 @@ interface SourceContext {
   [key: string]: string;
 }
 
+/**
+ * Environments that this system might be running in.
+ * Helps provide platform-specific information and integration.
+ */
+export enum Platforms {
+  /** Google Cloud Functions */
+  CLOUD_FUNCTION = 'cloud_function',
+  /** Any other platform. */
+  DEFAULT = 'default',
+}
+
 /**
  * Formats a breakpoint object prefixed with a provided message as a string
  * intended for logging.
@@ -544,6 +555,7 @@ export class Debuglet extends EventEmitter {
       'agent.name': packageInfo.name,
       'agent.version': packageInfo.version,
       projectid: projectId,
+      platform: Debuglet.getPlatform(),
     };
 
     if (serviceContext) {
@@ -604,6 +616,19 @@ export class Debuglet extends EventEmitter {
     return new Debuggee(properties);
   }
 
+  /**
+   * Use environment vars to infer the current platform.
+   * For now this is only Cloud Functions and other.
+   */
+  private static getPlatform(): Platforms {
+    const {FUNCTION_NAME, FUNCTION_TARGET} = process.env;
+    // (In theory) only the Google Cloud Functions environment will have these env vars.
+    if (FUNCTION_NAME || FUNCTION_TARGET) {
+      return Platforms.CLOUD_FUNCTION;
+    }
+    return Platforms.DEFAULT;
+  }
+
   static runningOnGCP(): Promise<boolean> {
     return metadata.isAvailable();
   }

test/test-debuglet.ts

@@ -26,7 +26,12 @@ import * as stackdriver from '../src/types/stackdriver';
 
 DEFAULT_CONFIG.allowExpressions = true;
 DEFAULT_CONFIG.workingDirectory = path.join(__dirname, '..', '..');
-import {Debuglet, CachedPromise, FindFilesResult} from '../src/agent/debuglet';
+import {
+  Debuglet,
+  CachedPromise,
+  FindFilesResult,
+  Platforms,
+} from '../src/agent/debuglet';
 import {ScanResults} from '../src/agent/io/scanner';
 import * as extend from 'extend';
 import {Debug} from '../src/client/stackdriver/debug';
@@ -1542,6 +1547,48 @@ describe('Debuglet', () => {
       );
       assert.strictEqual(debuggee.canaryMode, 'CANARY_MODE_ALWAYS_DISABLED');
     });
+
+    it('should correctly identify default platform.', () => {
+      const debuggee = Debuglet.createDebuggee(
+        'some project',
+        'id',
+        {service: 'some-service', version: 'production'},
+        {},
+        false,
+        packageInfo
+      );
+      assert.ok(debuggee.labels!.platform === Platforms.DEFAULT);
+    });
+
+    it('should correctly identify GCF (legacy) platform.', () => {
+      // GCF sets this env var on older runtimes.
+      process.env.FUNCTION_NAME = 'mock';
+      const debuggee = Debuglet.createDebuggee(
+        'some project',
+        'id',
+        {service: 'some-service', version: 'production'},
+        {},
+        false,
+        packageInfo
+      );
+      assert.ok(debuggee.labels!.platform === Platforms.CLOUD_FUNCTION);
+      delete process.env.FUNCTION_NAME; // Don't contaminate test environment.
+    });
+
+    it('should correctly identify GCF (modern) platform.', () => {
+      // GCF sets this env var on modern runtimes.
+      process.env.FUNCTION_TARGET = 'mock';
+      const debuggee = Debuglet.createDebuggee(
+        'some project',
+        'id',
+        {service: 'some-service', version: 'production'},
+        {},
+        false,
+        packageInfo
+      );
+      assert.ok(debuggee.labels!.platform === Platforms.CLOUD_FUNCTION);
+      delete process.env.FUNCTION_TARGET; // Don't contaminate test environment.
+    });
   });
 
   describe('_createUniquifier', () => {