🔧 #248 Disable span and metrics by default (#254)

Author: gernest

pkg/telemetry/telemetry.go

@@ -10,8 +10,10 @@ import (
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/sdk/metric"
 	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/resource"
+	"go.opentelemetry.io/otel/sdk/trace"
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
 	"go.uber.org/zap"
@@ -63,7 +65,7 @@ func NewTelemetry(cfg *Config) (*Telemetry, error) {
 		resourceAttr...,
 	)
 
-	spanExporter, err := autoexport.NewSpanExporter(context.Background())
+	spanExporter, err := newSpanExporter()
 	if err != nil {
 		return nil, err
 	}
@@ -77,7 +79,7 @@ func NewTelemetry(cfg *Config) (*Telemetry, error) {
 	otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{},
 		propagation.Baggage{}, b3.New()))
 
-	metricsReader, err := autoexport.NewMetricReader(context.Background())
+	metricsReader, err := newMetricReader()
 	if err != nil {
 		return nil, err
 	}
@@ -108,3 +110,31 @@ func NewTelemetryMock() *Telemetry {
 		Logger: NewLoggerMock(),
 	}
 }
+
+func newMetricReader() (sdkmetric.Reader, error) {
+	return autoexport.NewMetricReader(context.Background(),
+		autoexport.WithFallbackMetricReader(func(_ context.Context) (sdkmetric.Reader, error) {
+			return metric.NewManualReader(), nil
+		}),
+	)
+}
+
+func newSpanExporter() (sdktrace.SpanExporter, error) {
+	return autoexport.NewSpanExporter(context.Background(), autoexport.WithFallbackSpanExporter(
+		func(_ context.Context) (sdktrace.SpanExporter, error) {
+			return noopSpanExporter{}, nil
+		},
+	))
+}
+
+type noopSpanExporter struct{}
+
+var _ trace.SpanExporter = noopSpanExporter{}
+
+func (e noopSpanExporter) ExportSpans(_ context.Context, _ []trace.ReadOnlySpan) error {
+	return nil
+}
+
+func (e noopSpanExporter) Shutdown(_ context.Context) error {
+	return nil
+}

pkg/telemetry/telemetry_test.go

@@ -1,12 +1,32 @@
 package telemetry
 
 import (
+	"context"
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/otel/sdk/metric"
 )
 
 func TestTelemetry_Creation(t *testing.T) {
 	_, err := NewTelemetry(DefaultConfig())
 	require.NoError(t, err)
 }
+
+func TestDefaults_noopExporters(t *testing.T) {
+	// By default all otel providers must be noop. Since we don't have otel setup
+	// in test environment, this test ensures all providers are noop.
+	mr, err := newMetricReader()
+	if err != nil {
+		t.Fatal(err)
+	}
+	// ensures we have a noop metric.ManualReader
+	_ = mr.(*metric.ManualReader).Shutdown(context.Background())
+
+	se, err := newSpanExporter()
+	if err != nil {
+		t.Fatal(err)
+	}
+	// ensures we have a noopSpanExporter
+	_ = se.(noopSpanExporter).Shutdown(context.Background())
+}