feat(exporter): Support OTEL_EXPORTER_OTLP_PROTOCOL=http/protobuf for…

… exporting traces via http

Closes open-telemetry#3412

autoinstrumentation/nodejs/src/autoinstrumentation.ts

@@ -1,5 +1,6 @@
 import { getNodeAutoInstrumentations } from '@opentelemetry/auto-instrumentations-node';
 import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-grpc';
+import { OTLPTraceExporter as OTLPTraceExporterHTTP } from '@opentelemetry/exporter-trace-otlp-http';
 import { OTLPMetricExporter } from '@opentelemetry/exporter-metrics-otlp-grpc';
 import { PrometheusExporter } from '@opentelemetry/exporter-prometheus';
 import { PeriodicExportingMetricReader } from '@opentelemetry/sdk-metrics';
@@ -12,6 +13,19 @@ import { diag } from '@opentelemetry/api';
 
 import { NodeSDK } from '@opentelemetry/sdk-node';
 
+function getTraceExporter() {
+    switch (process.env.OTEL_EXPORTER_OTLP_PROTOCOL) {
+        case undefined:
+        case '':
+        case 'grpc':
+            return new OTLPTraceExporter();
+        case 'http/protobuf':
+            return new OTLPTraceExporterHTTP();
+        default:
+            throw Error(`Using exporter based on environment variable OTEL_EXPORTER_OTLP_PROTOCOL: ${process.env.OTEL_EXPORTER_OTLP_PROTOCOL} is not implemented!`);
+    }
+}
+
 function getMetricReader() {
     switch (process.env.OTEL_METRICS_EXPORTER) {
         case undefined:
@@ -35,7 +49,7 @@ function getMetricReader() {
 const sdk = new NodeSDK({
     autoDetectResources: true,
     instrumentations: [getNodeAutoInstrumentations()],
-    traceExporter: new OTLPTraceExporter(),
+    traceExporter: getTraceExporter(),
     metricReader: getMetricReader(),
     resourceDetectors:
         [