fix(otlp-http-exporter): remove content length header (#2879)

experimental/CHANGELOG.md

@@ -8,6 +8,7 @@ All notable changes to experimental packages in this project will be documented
 
 * [#2707](https://github.com/open-telemetry/opentelemetry-js/pull/2707) feat(sdk-metrics-base): update metric exporter interfaces ([@srikanthccv](https://github.com/srikanthccv))
 * [#2687](https://github.com/open-telemetry/opentelemetry-js/pull/2687) feat(api-metrics): remove observable types ([@legendecas](https://github.com/legendecas))
+* [#2879](https://github.com/open-telemetry/opentelemetry-js/pull/2879) fix(otlp-http-exporter): remove content length header ([@svetlanabrennan](https://github.com/svetlanabrennan))
 
 ### :rocket: (Enhancement)
 

experimental/packages/exporter-trace-otlp-http/src/platform/node/util.ts

@@ -50,7 +50,6 @@ export function sendWithHttp<ExportItem, ServiceRequest>(
     path: parsedUrl.pathname,
     method: 'POST',
     headers: {
-      'Content-Length': Buffer.byteLength(data),
       'Content-Type': contentType,
       ...collector.headers,
     },
@@ -96,9 +95,7 @@ export function sendWithHttp<ExportItem, ServiceRequest>(
       break;
     }
     default:
-      req.write(data);
-      req.end();
-
+      req.end(data);
       break;
   }
 }

experimental/packages/opentelemetry-exporter-metrics-otlp-http/test/node/CollectorMetricExporter.test.ts

@@ -148,7 +148,7 @@ describe('OTLPMetricExporter - node with json over http', () => {
   describe('export', () => {
     beforeEach(async () => {
       stubRequest = sinon.stub(http, 'request').returns(fakeRequest as any);
-      stubWrite = sinon.stub(fakeRequest, 'write');
+      stubWrite = sinon.stub(fakeRequest, 'end');
       collectorExporterConfig = {
         headers: {
           foo: 'bar',

experimental/packages/opentelemetry-exporter-metrics-otlp-proto/test/OTLPMetricExporter.test.ts

@@ -179,9 +179,9 @@ describe('OTLPMetricExporter - node with proto over http', () => {
       collectorExporter.export(metrics, () => {});
 
       sinon.stub(http, 'request').returns({
-        end: () => {},
+        write: () => {},
         on: () => {},
-        write: (...writeArgs: any[]) => {
+        end: (...writeArgs: any[]) => {
           const ExportTraceServiceRequestProto = getExportRequestProto();
           const data = ExportTraceServiceRequestProto?.decode(writeArgs[0]);
           const json = data?.toJSON() as otlpTypes.opentelemetryProto.collector.metrics.v1.ExportMetricsServiceRequest;