OTLP Exporter documentation example misleading (#838)

Author: HiveTraum

ext/opentelemetry-ext-otlp/src/opentelemetry/ext/otlp/__init__.py

@@ -30,10 +30,17 @@
 
     from opentelemetry import trace
     from opentelemetry.ext.otlp.trace_exporter import OTLPSpanExporter
+    from opentelemetry.sdk.resources import Resource
     from opentelemetry.sdk.trace import TracerProvider
     from opentelemetry.sdk.trace.export import BatchExportSpanProcessor
 
-    trace.set_tracer_provider(TracerProvider())
+    # Resource can be required for some backends, e.g. Jaeger
+    # If resource wouldn't be set - traces wouldn't appears in Jaeger
+    resource = Resource(labels=labels={
+        "service.name": "service"
+    })
+
+    trace.set_tracer_provider(TracerProvider(resource=resource)))
     tracer = trace.get_tracer(__name__)
 
     otlp_exporter = OTLPSpanExporter(endpoint="localhost:55678")