feat(opentelemetry-js): infer zipkin service name from resource

packages/opentelemetry-exporter-zipkin/README.md

@@ -17,7 +17,7 @@ npm install --save @opentelemetry/exporter-zipkin
 
 ## Usage
 
-Install the exporter on your application and pass the options, it must contain a service name.
+Install the exporter on your application and pass the options. `serviceName` is an optional string. If omitted, the exporter will first try to get the service name from the Resource. If no service name can be detected on the Resource, a fallback name of "OpenTelemetry Service" will be used.
 
 ```js
 const { ZipkinExporter } = require('@opentelemetry/exporter-zipkin');

packages/opentelemetry-exporter-zipkin/src/types.ts

@@ -21,7 +21,7 @@ import * as api from '@opentelemetry/api';
  */
 export interface ExporterConfig {
   logger?: api.Logger;
-  serviceName: string;
+  serviceName?: string;
   url?: string;
   // Optional mapping overrides for OpenTelemetry status code and description.
   statusCodeTagName?: string;

packages/opentelemetry-exporter-zipkin/src/zipkin.ts

@@ -27,19 +27,21 @@ import {
   statusDescriptionTagName,
 } from './transform';
 import { OT_REQUEST_HEADER } from './utils';
+import { SERVICE_RESOURCE } from '@opentelemetry/resources';
 /**
  * Zipkin Exporter
  */
 export class ZipkinExporter implements SpanExporter {
   static readonly DEFAULT_URL = 'http://localhost:9411/api/v2/spans';
+  private readonly DEFAULT_SERVICE_NAME = 'OpenTelemetry Service';
   private readonly _logger: api.Logger;
-  private readonly _serviceName: string;
   private readonly _statusCodeTagName: string;
   private readonly _statusDescriptionTagName: string;
   private readonly _reqOpts: http.RequestOptions;
+  private _serviceName?: string;
   private _isShutdown: boolean;
 
-  constructor(config: zipkinTypes.ExporterConfig) {
+  constructor(config: zipkinTypes.ExporterConfig = {}) {
     const urlStr = config.url || ZipkinExporter.DEFAULT_URL;
     const urlOpts = url.parse(urlStr);
 
@@ -68,12 +70,18 @@ export class ZipkinExporter implements SpanExporter {
     spans: ReadableSpan[],
     resultCallback: (result: ExportResult) => void
   ) {
+    if (typeof this._serviceName !== 'string') {
+      this._serviceName = String(
+        spans[0].resource.labels[SERVICE_RESOURCE.NAME] ||
+          this.DEFAULT_SERVICE_NAME
+      );
+    }
     this._logger.debug('Zipkin exporter export');
     if (this._isShutdown) {
       setTimeout(() => resultCallback(ExportResult.FAILED_NOT_RETRYABLE));
       return;
     }
-    return this._sendSpans(spans, resultCallback);
+    return this._sendSpans(spans, this._serviceName, resultCallback);
   }
 
   /**
@@ -87,26 +95,22 @@ export class ZipkinExporter implements SpanExporter {
     this._isShutdown = true;
   }
 
-  /**
-   * Transforms an OpenTelemetry span to a Zipkin span.
-   */
-  private _toZipkinSpan(span: ReadableSpan): zipkinTypes.Span {
-    return toZipkinSpan(
-      span,
-      this._serviceName,
-      this._statusCodeTagName,
-      this._statusDescriptionTagName
-    );
-  }
-
   /**
    * Transform spans and sends to Zipkin service.
    */
   private _sendSpans(
     spans: ReadableSpan[],
+    serviceName: string,
     done?: (result: ExportResult) => void
   ) {
-    const zipkinSpans = spans.map(span => this._toZipkinSpan(span));
+    const zipkinSpans = spans.map(span =>
+      toZipkinSpan(
+        span,
+        serviceName,
+        this._statusCodeTagName,
+        this._statusDescriptionTagName
+      )
+    );
     return this._send(zipkinSpans, (result: ExportResult) => {
       if (done) {
         return done(result);

packages/opentelemetry-exporter-zipkin/test/zipkin.test.ts

@@ -28,6 +28,7 @@ import { ZipkinExporter } from '../src';
 import * as zipkinTypes from '../src/types';
 import { OT_REQUEST_HEADER } from '../src/utils';
 import { TraceFlags } from '@opentelemetry/api';
+import { SERVICE_RESOURCE } from '@opentelemetry/resources';
 
 const MICROS_PER_SECS = 1e6;
 
@@ -331,6 +332,152 @@ describe('ZipkinExporter', () => {
         done();
       });
     });
+
+    it('should set serviceName to "Opentelemetry Service" by default', () => {
+      const scope = nock('http://localhost:9411')
+        .post('/api/v2/spans')
+        .replyWithError(new Error('My Socket Error'));
+
+      const parentSpanId = '5c1c63257de34c67';
+      const startTime = 1566156729709;
+      const duration = 2000;
+
+      const span1: ReadableSpan = {
+        name: 'my-span',
+        kind: api.SpanKind.INTERNAL,
+        parentSpanId,
+        spanContext: {
+          traceId: 'd4cda95b652f4a1592b449d5929fda1b',
+          spanId: '6e0c63257de34c92',
+          traceFlags: TraceFlags.NONE,
+        },
+        startTime: [startTime, 0],
+        endTime: [startTime + duration, 0],
+        ended: true,
+        duration: [duration, 0],
+        status: {
+          code: api.CanonicalCode.OK,
+        },
+        attributes: {
+          key1: 'value1',
+          key2: 'value2',
+        },
+        links: [],
+        events: [
+          {
+            name: 'my-event',
+            time: [startTime + 10, 0],
+            attributes: { key3: 'value3' },
+          },
+        ],
+        resource: Resource.empty(),
+      };
+      const span2: ReadableSpan = {
+        name: 'my-span',
+        kind: api.SpanKind.SERVER,
+        spanContext: {
+          traceId: 'd4cda95b652f4a1592b449d5929fda1b',
+          spanId: '6e0c63257de34c92',
+          traceFlags: TraceFlags.NONE,
+        },
+        startTime: [startTime, 0],
+        endTime: [startTime + duration, 0],
+        ended: true,
+        duration: [duration, 0],
+        status: {
+          code: api.CanonicalCode.OK,
+        },
+        attributes: {},
+        links: [],
+        events: [],
+        resource: Resource.empty(),
+      };
+
+      const exporter = new ZipkinExporter({});
+
+      exporter.export([span1, span2], (result: ExportResult) => {
+        scope.done();
+        assert.equal(exporter['_serviceName'], 'OpenTelemetry Service');
+      });
+    });
+
+    it('should set serviceName if resource has one', () => {
+      const resource_service_name = 'resource_service_name';
+
+      const scope = nock('http://localhost:9411')
+        .post('/api/v2/spans')
+        .replyWithError(new Error('My Socket Error'));
+
+      const parentSpanId = '5c1c63257de34c67';
+      const startTime = 1566156729709;
+      const duration = 2000;
+
+      const span1: ReadableSpan = {
+        name: 'my-span',
+        kind: api.SpanKind.INTERNAL,
+        parentSpanId,
+        spanContext: {
+          traceId: 'd4cda95b652f4a1592b449d5929fda1b',
+          spanId: '6e0c63257de34c92',
+          traceFlags: TraceFlags.NONE,
+        },
+        startTime: [startTime, 0],
+        endTime: [startTime + duration, 0],
+        ended: true,
+        duration: [duration, 0],
+        status: {
+          code: api.CanonicalCode.OK,
+        },
+        attributes: {
+          key1: 'value1',
+          key2: 'value2',
+        },
+        links: [],
+        events: [
+          {
+            name: 'my-event',
+            time: [startTime + 10, 0],
+            attributes: { key3: 'value3' },
+          },
+        ],
+        resource: new Resource({
+          [SERVICE_RESOURCE.NAME]: resource_service_name,
+        }),
+      };
+      const span2: ReadableSpan = {
+        name: 'my-span',
+        kind: api.SpanKind.SERVER,
+        spanContext: {
+          traceId: 'd4cda95b652f4a1592b449d5929fda1b',
+          spanId: '6e0c63257de34c92',
+          traceFlags: TraceFlags.NONE,
+        },
+        startTime: [startTime, 0],
+        endTime: [startTime + duration, 0],
+        ended: true,
+        duration: [duration, 0],
+        status: {
+          code: api.CanonicalCode.OK,
+        },
+        attributes: {},
+        links: [],
+        events: [],
+        resource: Resource.empty(),
+      };
+
+      const exporter = new ZipkinExporter({});
+
+      exporter.export([span1, span2], (result: ExportResult) => {
+        scope.done();
+        assert.equal(exporter['_serviceName'], resource_service_name);
+
+        // checking if service name remains consistent in further exports
+        exporter.export([span2], (result: ExportResult) => {
+          scope.done();
+          assert.equal(exporter['_serviceName'], resource_service_name);
+        });
+      });
+    });
   });
 
   describe('shutdown', () => {