fix(core): append correct OTLP paths for HTTP exporters (#16836)

Author: sebastien-prudhomme

packages/core/src/telemetry/sdk.test.ts

@@ -113,13 +113,13 @@ describe('Telemetry SDK', () => {
     await initializeTelemetry(mockConfig);
 
     expect(OTLPTraceExporterHttp).toHaveBeenCalledWith({
-      url: 'http://localhost:4318/',
+      url: 'http://localhost:4318/v1/traces',
     });
     expect(OTLPLogExporterHttp).toHaveBeenCalledWith({
-      url: 'http://localhost:4318/',
+      url: 'http://localhost:4318/v1/logs',
     });
     expect(OTLPMetricExporterHttp).toHaveBeenCalledWith({
-      url: 'http://localhost:4318/',
+      url: 'http://localhost:4318/v1/metrics',
     });
     expect(NodeSDK.prototype.start).toHaveBeenCalled();
   });
@@ -141,7 +141,7 @@ describe('Telemetry SDK', () => {
     );
     await initializeTelemetry(mockConfig);
     expect(OTLPTraceExporterHttp).toHaveBeenCalledWith(
-      expect.objectContaining({ url: 'https://my-collector.com/' }),
+      expect.objectContaining({ url: 'https://my-collector.com/v1/traces' }),
     );
   });
 

packages/core/src/telemetry/sdk.ts

@@ -275,15 +275,21 @@ export async function initializeTelemetry(
     });
   } else if (useOtlp) {
     if (otlpProtocol === 'http') {
+      const buildUrl = (path: string) => {
+        const url = new URL(parsedEndpoint);
+        // Join the existing pathname with the new path, handling trailing slashes.
+        url.pathname = [url.pathname.replace(/\/$/, ''), path].join('/');
+        return url.href;
+      };
       spanExporter = new OTLPTraceExporterHttp({
-        url: parsedEndpoint,
+        url: buildUrl('v1/traces'),
       });
       logExporter = new OTLPLogExporterHttp({
-        url: parsedEndpoint,
+        url: buildUrl('v1/logs'),
       });
       metricReader = new PeriodicExportingMetricReader({
         exporter: new OTLPMetricExporterHttp({
-          url: parsedEndpoint,
+          url: buildUrl('v1/metrics'),
         }),
         exportIntervalMillis: 10000,
       });