Adds possibility to set headers to zipkin exporter

packages/opentelemetry-exporter-zipkin/README.md

@@ -24,8 +24,12 @@ Install the exporter on your application and pass the options. `serviceName` is
 const { ZipkinExporter } = require('@opentelemetry/exporter-zipkin');
 
 // Add your zipkin url (`http://localhost:9411/api/v2/spans` is used as
-// default) and application name to the Zipkin options
+// default) and application name to the Zipkin options.
+// You can also define your custom headers which will be added automatically.
 const options = {
+  headers: {
+    'my-header': 'header-value',
+  },
   url: 'your-zipkin-url',
   serviceName: 'your-application-name'
 }

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

@@ -20,6 +20,7 @@ import * as api from '@opentelemetry/api';
  * Exporter config
  */
 export interface ExporterConfig {
+  headers?: { [key: string]: string };
   logger?: api.Logger;
   serviceName?: string;
   url?: string;

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

@@ -52,6 +52,7 @@ export class ZipkinExporter implements SpanExporter {
         headers: {
           'Content-Type': 'application/json',
           [OT_REQUEST_HEADER]: 1,
+          ...config.headers,
         },
       },
       urlOpts

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

@@ -97,6 +97,21 @@ describe('ZipkinExporter', () => {
       assert.ok(typeof exporter.export === 'function');
       assert.ok(typeof exporter.shutdown === 'function');
     });
+    it('should construct an exporter with headers', () => {
+      const exporter = new ZipkinExporter({
+        headers: {
+          foo: 'bar',
+        },
+      });
+      interface ExporterWithHeaders {
+        _reqOpts: {
+          headers: { [key: string]: string };
+        };
+      }
+      const exporterWithHeaders = (exporter as unknown) as ExporterWithHeaders;
+
+      assert.ok(exporterWithHeaders._reqOpts.headers['foo'] === 'bar');
+    });
   });
 
   describe('export', () => {