fix(opentelemetry-exporter-jaeger): adds header to avoid infinity loop

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

@@ -21,6 +21,7 @@ import { ReadableSpan, SpanExporter } from '@opentelemetry/tracing';
 import { Socket } from 'dgram';
 import { spanToThrift } from './transform';
 import * as jaegerTypes from './types';
+import { OT_REQUEST_HEADER } from './utils';
 
 /**
  * Format and sends span information to Jaeger Exporter.
@@ -46,10 +47,13 @@ export class JaegerExporter implements SpanExporter {
     // JAEGER_AGENT_PORT to send UDP traces to a different host:port. If JAEGER_ENDPOINT is set, the client sends traces
     // to the endpoint via HTTP, making the JAEGER_AGENT_HOST and JAEGER_AGENT_PORT unused. If JAEGER_ENDPOINT is secured,
     // HTTP basic authentication can be performed by setting the JAEGER_USER and JAEGER_PASSWORD environment variables.
-    this._sender = config.endpoint
-      ? new jaegerTypes.HTTPSender(config)
-      : new jaegerTypes.UDPSender(config);
-    this._sender = new jaegerTypes.UDPSender(config);
+    if (config.endpoint) {
+      this._sender = new jaegerTypes.HTTPSender(config);
+      this._sender._httpOptions.headers[OT_REQUEST_HEADER] = 1;
+    } else {
+      this._sender = config.endpoint = new jaegerTypes.UDPSender(config);
+    }
+
     if (this._sender._client instanceof Socket) {
       // unref socket to prevent it from keeping the process running
       this._sender._client.unref();

packages/opentelemetry-exporter-jaeger/src/utils.ts

@@ -0,0 +1,17 @@
+/*!
+ * Copyright 2020, OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+export const OT_REQUEST_HEADER = 'x-opentelemetry-outgoing-request';