Enable to receive credentials object in creating Stackdriver exporter (#541)

* Enable to receive credentials object in creating Stackdriver exporter

* Add test suite with credentials option

* Fix credentials field comment

* Update CHANGELOG.md

Author: yamadayuki

CHANGELOG.md

@@ -5,6 +5,7 @@ All notable changes to this project will be documented in this file.
 ## Unreleased
 
 - Exporter/Stats/Stackdriver: Add support for exemplar
+- exporter-stackdriver: Add support the credentials option used for authentication instead of your application default credentials
 
 ## 0.0.13 - 2019-05-20
 - Exporter/Stats/Prometheus: Fix missing tags for HTTP metrics

packages/opencensus-exporter-stackdriver/src/stackdriver-cloudtrace.ts

@@ -16,14 +16,15 @@
 
 import {Exporter, ExporterBuffer, Span as OCSpan, SpanContext} from '@opencensus/core';
 import {logger, Logger} from '@opencensus/core';
-import {auth, JWT} from 'google-auth-library';
+import {auth as globalAuth, GoogleAuth, JWT} from 'google-auth-library';
 import {google} from 'googleapis';
 import {getDefaultResource} from './common-utils';
 import {createAttributes, createLinks, createTimeEvents, getResourceLabels, stringToTruncatableString} from './stackdriver-cloudtrace-utils';
 import {AttributeValue, Span, SpansWithCredentials, StackdriverExporterOptions} from './types';
 
 google.options({headers: {'x-opencensus-outgoing-request': 0x1}});
 const cloudTrace = google.cloudtrace('v2');
+let auth = globalAuth;
 
 /** Format and sends span information to Stackdriver */
 export class StackdriverTraceExporter implements Exporter {
@@ -39,6 +40,9 @@ export class StackdriverTraceExporter implements Exporter {
     this.exporterBuffer = new ExporterBuffer(this, options);
     this.RESOURCE_LABELS =
         getResourceLabels(getDefaultResource(this.projectId));
+    if (options.credentials) {
+      auth = new GoogleAuth({credentials: options.credentials});
+    }
   }
 
   /**

packages/opencensus-exporter-stackdriver/src/stackdriver-monitoring.ts

@@ -15,7 +15,7 @@
  */
 
 import {logger, Logger, Measurement, Metric, MetricDescriptor as OCMetricDescriptor, MetricProducerManager, Metrics, StatsEventListener, TagKey, TagValue, version, View} from '@opencensus/core';
-import {auth, JWT} from 'google-auth-library';
+import {auth as globalAuth, GoogleAuth, JWT} from 'google-auth-library';
 import {google} from 'googleapis';
 import {getDefaultResource} from './common-utils';
 import {createMetricDescriptorData, createTimeSeriesList} from './stackdriver-monitoring-utils';
@@ -31,6 +31,7 @@ const OC_HEADER = {
 
 google.options({headers: OC_HEADER});
 const monitoring = google.monitoring('v3');
+let auth = globalAuth;
 
 /** Format and sends Stats to Stackdriver */
 export class StackdriverStatsExporter implements StatsEventListener {
@@ -63,6 +64,9 @@ export class StackdriverStatsExporter implements StatsEventListener {
       this.onMetricUploadError = options.onMetricUploadError;
     }
     this.DEFAULT_RESOURCE = getDefaultResource(this.projectId);
+    if (options.credentials) {
+      auth = new GoogleAuth({credentials: options.credentials});
+    }
   }
 
   /**

packages/opencensus-exporter-stackdriver/src/types.ts

@@ -15,7 +15,7 @@
  */
 
 import {Bucket, ExporterConfig} from '@opencensus/core';
-import {JWT} from 'google-auth-library';
+import {JWT, JWTInput} from 'google-auth-library';
 
 export type Span = {
   name?: string,
@@ -151,6 +151,11 @@ export interface StackdriverExporterOptions extends ExporterConfig {
    * of a stackdriver metric. Optional
    */
   prefix?: string;
+  /**
+   * If this field is set, its contents will be used for authentication
+   * instead of your application default credentials. Optional
+   */
+  credentials?: JWTInput;
 
   /**
    * Is called whenever the exporter fails to upload metrics to stackdriver.

packages/opencensus-exporter-stackdriver/test/test-stackdriver-cloudtrace.ts

@@ -16,6 +16,7 @@
 
 import {CoreTracer, logger, Span as OCSpan, version} from '@opencensus/core';
 import * as assert from 'assert';
+import * as fs from 'fs';
 import * as nock from 'nock';
 
 import {Span, StackdriverExporterOptions, StackdriverTraceExporter} from '../src/';
@@ -225,5 +226,68 @@ describe('Stackdriver Trace Exporter', function() {
             });
           });
     });
+
+    describe('with credentials option', () => {
+      const FAKE_CREDENTIALS = JSON.parse(
+          fs.readFileSync(__dirname + '/fixtures/fakecredentials.json')
+              .toString());
+
+      before(() => {
+        exporterOptions = {
+          projectId: PROJECT_ID,
+          bufferTimeout: 200,
+          logger: testLogger,
+          credentials: FAKE_CREDENTIALS,
+        };
+      });
+
+      it('should export traces to stackdriver', () => {
+        return tracer.startRootSpan(
+            {name: 'sdExportTestRootSpan'}, async (rootSpan: OCSpan) => {
+              const span =
+                  tracer.startChildSpan({name: 'sdExportTestChildSpan'});
+
+              nocks.oauth2(body => true);
+              nocks.batchWrite(PROJECT_ID, (body: {spans: Span[]}): boolean => {
+                assert.strictEqual(body.spans.length, 2);
+                const spans = body.spans;
+                assert.strictEqual(spans[0].spanId, rootSpan.id);
+                assert.strictEqual(spans[1].spanId, span.id);
+                return true;
+              });
+              span.end();
+              rootSpan.end();
+
+              return exporter.publish([rootSpan]).then(result => {
+                assert.ok(result.indexOf('batchWriteSpans sucessfully') >= 0);
+              });
+            });
+      });
+
+      it('should fail exporting by network error', async () => {
+        nock('https://cloudtrace.googleapis.com')
+            .intercept(
+                '/v2/projects/' + exporterOptions.projectId +
+                    '/traces:batchWrite',
+                'post')
+            .reply(443, 'Simulated Network Error');
+
+        nocks.oauth2(body => true);
+
+        return tracer.startRootSpan(
+            {name: 'sdErrorExportTestRootSpan'}, (rootSpan: OCSpan) => {
+              const span =
+                  tracer.startChildSpan({name: 'sdErrorExportTestChildSpan'});
+              span.end();
+              rootSpan.end();
+
+              return exporter.publish([rootSpan]).then(result => {
+                assert.ok(
+                    result.message.indexOf(
+                        'batchWriteSpans error: Simulated Network Error') >= 0);
+              });
+            });
+      });
+    });
   });
 });