fix: trace FastStream without a broker telemetry middleware

docs/introduction/configuration.md

@@ -102,9 +102,13 @@ For FastAPI there is additionally:
   request on the benchmark endpoint, at the cost of two thirds of the spans disappearing from your
   trace view.
 
-For FastStream you must provide additionally:
+For FastStream there is additionally:
 
-- `opentelemetry_middleware_cls`
+- `opentelemetry_middleware_cls` - the broker telemetry middleware, e.g.
+  `faststream.redis.opentelemetry.RedisTelemetryMiddleware`. You must provide it to trace broker
+  messages. Without it the rest of the configuration above still applies: the exporter is built, the
+  health-check span is recorded unless `opentelemetry_generate_health_check_spans` is False, and any
+  `opentelemetry_instrumentors` are applied.
 
 
 ## Pyroscope

lite_bootstrap/bootstrappers/faststream_bootstrapper.py

@@ -143,11 +143,6 @@ def teardown(self) -> None:
 @dataclasses.dataclass(kw_only=True)
 class FastStreamOpenTelemetryInstrument(OpenTelemetryInstrument):
     bootstrap_config: FastStreamConfig
-    not_configured_reason = OpenTelemetryInstrument.not_configured_reason + " or opentelemetry_middleware_cls is empty"
-
-    @classmethod
-    def is_configured(cls, bootstrap_config: "FastStreamConfig") -> bool:  # ty: ignore[invalid-method-override]
-        return super().is_configured(bootstrap_config) and bool(bootstrap_config.opentelemetry_middleware_cls)
 
     def bootstrap(self) -> None:
         super().bootstrap()

tests/test_faststream_bootstrap.py

@@ -332,7 +332,13 @@ def test_faststream_bootstrap_builds_its_own_tracer_provider(broker: RedisBroker
         bootstrapper.teardown()
 
 
-def test_faststream_bootstrap_applies_opentelemetry_instrumentors(broker: RedisBroker) -> None:
+@pytest.mark.parametrize(
+    "middleware_cls", [RedisTelemetryMiddleware, None], ids=["with_middleware", "without_middleware"]
+)
+def test_faststream_bootstrap_applies_opentelemetry_instrumentors(
+    broker: RedisBroker,
+    middleware_cls: type | None,
+) -> None:
     recorded_tracer_providers: list[object] = []
 
     class RecordingInstrumentor(BaseInstrumentor):
@@ -346,13 +352,15 @@ def _uninstrument(self, **_kwargs: object) -> None: ...
 
     bootstrap_config = dataclasses.replace(
         build_faststream_config(broker=broker),
+        opentelemetry_middleware_cls=middleware_cls,
         opentelemetry_instrumentors=[RecordingInstrumentor()],
     )
     bootstrapper = FastStreamBootstrapper(bootstrap_config=bootstrap_config)
     bootstrapper.bootstrap()
     try:
         instruments = [one for one in bootstrapper.instruments if isinstance(one, FastStreamOpenTelemetryInstrument)]
         assert len(instruments) == 1
+        assert instruments[0]._tracer_provider is not None  # noqa: SLF001
         assert recorded_tracer_providers == [instruments[0]._tracer_provider]  # noqa: SLF001
     finally:
         bootstrapper.teardown()