metrics: added noop exporter

Aiven-Open · Jan 22, 2025 · 84f5293 · 84f5293
1 parent 618b21f
commit 84f5293
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Showing 2 changed files with 89 additions and 9 deletions.
diff --git a/src/schema_registry/telemetry/meter.py b/src/schema_registry/telemetry/meter.py
@@ -4,7 +4,7 @@
 """
 
 from dependency_injector.wiring import inject, Provide
-from karapace.config import Config
+from karapace.config import Config, KarapaceTelemetryOTelExporter
 from karapace.container import KarapaceContainer
 from opentelemetry import metrics
 from opentelemetry.exporter.otlp.proto.grpc.metric_exporter import OTLPMetricExporter
@@ -13,7 +13,32 @@
     MetricExporter,
     MetricReader,
     PeriodicExportingMetricReader,
+    MetricsData,
+    MetricExportResult,
 )
+from typing import Any
+
+
+class NOOPMetricExporter(MetricExporter):
+    """Implementation of :class:`MetricExporter` that does nothing.
+
+    This class is intended to be used when metrics exporting to an OTel backend is disabled
+    and the ConsoleExporter is too verbose to be used.
+    """
+
+    def export(
+        self,
+        metrics_data: MetricsData,
+        timeout_millis: float = 0,
+        **kwargs: Any,
+    ) -> MetricExportResult:
+        return MetricExportResult.SUCCESS
+
+    def shutdown(self, timeout_millis: float = 0, **kwargs: Any) -> None:
+        pass
+
+    def force_flush(self, _: float = 0) -> bool:
+        return True
 
 
 class Meter:
@@ -22,12 +47,20 @@ class Meter:
     def get_meter(config: Config = Provide[KarapaceContainer.config]) -> metrics.Meter:
         return metrics.get_meter_provider().get_meter(f"{config.tags.app}.meter")
 
+    @staticmethod
+    def get_metric_exporter(config: Config) -> MetricExporter:
+        match config.telemetry.otel_exporter:
+            case KarapaceTelemetryOTelExporter.NOOP:
+                return NOOPMetricExporter()
+            case KarapaceTelemetryOTelExporter.CONSOLE:
+                return ConsoleMetricExporter()
+            case KarapaceTelemetryOTelExporter.OTLP:
+                return OTLPMetricExporter(endpoint=config.telemetry.otel_endpoint_url)
+
     @staticmethod
     @inject
     def get_metric_reader(config: Config = Provide[KarapaceContainer.config]) -> MetricReader:
-        exporter: MetricExporter = ConsoleMetricExporter()
-        if config.telemetry.otel_endpoint_url:
-            exporter = OTLPMetricExporter(endpoint=config.telemetry.otel_endpoint_url)
+        exporter: MetricExporter = Meter.get_metric_exporter(config)
         return PeriodicExportingMetricReader(
             exporter=exporter,
             export_interval_millis=config.telemetry.metrics_export_interval_milliseconds,

diff --git a/tests/unit/schema_registry/telemetry/test_meter.py b/tests/unit/schema_registry/telemetry/test_meter.py
@@ -7,8 +7,9 @@
 
 from karapace.config import KarapaceTelemetry
 from karapace.container import KarapaceContainer
-from schema_registry.telemetry.meter import Meter
+from schema_registry.telemetry.meter import Meter, NOOPMetricExporter
 from unittest.mock import patch
+from opentelemetry.sdk.metrics.export import ConsoleMetricExporter, MetricExporter
 
 
 def test_meter(karapace_container: KarapaceContainer):
@@ -17,26 +18,72 @@ def test_meter(karapace_container: KarapaceContainer):
         mock_metrics.get_meter_provider.return_value.get_meter.assert_called_once_with("Karapace.meter")
 
 
+def test_get_metric_exporter_noop(karapace_container: KarapaceContainer) -> None:
+    config = karapace_container.config().set_config_defaults(
+        new_config={
+            "telemetry": KarapaceTelemetry(
+                otel_endpoint_url="http://otel:4317",
+                otel_exporter="NOOP",
+            )
+        }
+    )
+    exporter: MetricExporter = Meter.get_metric_exporter(config=config)
+    assert isinstance(exporter, NOOPMetricExporter)
+
+
+def test_get_metric_exporter_console(karapace_container: KarapaceContainer) -> None:
+    config = karapace_container.config().set_config_defaults(
+        new_config={
+            "telemetry": KarapaceTelemetry(
+                otel_endpoint_url="http://otel:4317",
+                otel_exporter="CONSOLE",
+            )
+        }
+    )
+    exporter: MetricExporter = Meter.get_metric_exporter(config=config)
+    assert isinstance(exporter, ConsoleMetricExporter)
+
+
+def test_get_metric_exporter_otlp(karapace_container: KarapaceContainer) -> None:
+    config = karapace_container.config().set_config_defaults(
+        new_config={
+            "telemetry": KarapaceTelemetry(
+                otel_endpoint_url="http://otel:4317",
+                otel_exporter="OTLP",
+            )
+        }
+    )
+    with patch("schema_registry.telemetry.meter.OTLPMetricExporter") as mock_otlp_exporter:
+        exporter: MetricExporter = Meter.get_metric_exporter(config=config)
+        mock_otlp_exporter.assert_called_once_with(endpoint="http://otel:4317")
+        assert exporter is mock_otlp_exporter.return_value
+
+
 def test_get_metric_reader_without_otel_endpoint(karapace_container: KarapaceContainer) -> None:
     config = karapace_container.config().set_config_defaults(
         new_config={"telemetry": KarapaceTelemetry(otel_endpoint_url=None)}
     )
     with (
-        patch("schema_registry.telemetry.meter.ConsoleMetricExporter") as mock_console_exporter,
+        patch("schema_registry.telemetry.meter.NOOPMetricExporter") as mock_noop_exporter,
         patch("schema_registry.telemetry.meter.PeriodicExportingMetricReader") as mock_periodic_exporting_metric_reader,
     ):
         reader = Meter.get_metric_reader(config=config)
-        mock_console_exporter.assert_called_once()
+        mock_noop_exporter.assert_called_once()
         mock_periodic_exporting_metric_reader.assert_called_once_with(
-            exporter=mock_console_exporter.return_value,
+            exporter=mock_noop_exporter.return_value,
             export_interval_millis=10000,
         )
         assert reader is mock_periodic_exporting_metric_reader.return_value
 
 
 def test_get_metric_reader_with_otel_endpoint(karapace_container: KarapaceContainer) -> None:
     config = karapace_container.config().set_config_defaults(
-        new_config={"telemetry": KarapaceTelemetry(otel_endpoint_url="http://otel:4317")}
+        new_config={
+            "telemetry": KarapaceTelemetry(
+                otel_endpoint_url="http://otel:4317",
+                otel_exporter="OTLP",
+            )
+        }
     )
     with (
         patch("schema_registry.telemetry.meter.OTLPMetricExporter") as mock_otlp_exporter,