Initial QSfera import

Server/pkg/tracing/tracing.go

@@ -0,0 +1,127 @@
+package tracing
+
+import (
+	"context"
+	"fmt"
+
+	rtrace "github.com/opencloud-eu/reva/v2/pkg/trace"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/exporters/stdout/stdouttrace"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.37.0"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// Propagator ensures the importer module uses the same trace propagation strategy.
+var Propagator = propagation.NewCompositeTextMapPropagator(
+	propagation.Baggage{},
+	propagation.TraceContext{},
+)
+
+// Deprecated: GetServiceTraceProvider returns a configured open-telemetry trace provider. Use GetTraceProvider.
+func GetServiceTraceProvider(exporter, serviceName string) (trace.TracerProvider, error) {
+	return GetTraceProvider(context.Background(), exporter, serviceName)
+}
+
+// GetPropagator gets a configured propagator.
+func GetPropagator() propagation.TextMapPropagator {
+	return propagation.NewCompositeTextMapPropagator(
+		propagation.Baggage{},
+		propagation.TraceContext{},
+	)
+}
+
+// GetTraceProvider returns a configured open-telemetry trace provider.
+func GetTraceProvider(ctx context.Context, exporter, serviceName string) (*sdktrace.TracerProvider, error) {
+
+	// Create resource - shared across all exporters
+	resources, err := createResource(ctx, serviceName)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create resource: %w", err)
+	}
+
+	var tp *sdktrace.TracerProvider
+
+	switch exporter {
+	case "", "none":
+		// No-op exporter - never sample
+		tp = sdktrace.NewTracerProvider(
+			sdktrace.WithSampler(sdktrace.NeverSample()),
+			sdktrace.WithResource(resources),
+		)
+
+	case "console":
+		// Console exporter - prints to stdout (useful for debugging)
+		consoleExporter, err := stdouttrace.New(
+			stdouttrace.WithPrettyPrint(),
+		)
+		if err != nil {
+			return nil, fmt.Errorf("failed to create console exporter: %w", err)
+		}
+
+		// Use SimpleSpanProcessor for console to get immediate output
+		tp = sdktrace.NewTracerProvider(
+			sdktrace.WithSpanProcessor(sdktrace.NewSimpleSpanProcessor(consoleExporter)),
+			sdktrace.WithResource(resources),
+		)
+
+	case "otlp":
+		// OTLP exporter - connects to collector
+		// This automatically reads:
+		// - OTEL_EXPORTER_OTLP_ENDPOINT
+		// - OTEL_EXPORTER_OTLP_TRACES_ENDPOINT (takes precedence)
+		// - OTEL_EXPORTER_OTLP_HEADERS
+		// - OTEL_EXPORTER_OTLP_INSECURE
+		// - OTEL_EXPORTER_OTLP_CERTIFICATE (for custom CA)
+		otlpExporter, err := otlptracegrpc.New(ctx)
+		if err != nil {
+			return nil, fmt.Errorf("failed to create OTLP exporter: %w", err)
+		}
+
+		// Create tracer provider
+		// This automatically reads:
+		// - OTEL_TRACES_SAMPLER
+		// - OTEL_TRACES_SAMPLER_ARG
+		tp = sdktrace.NewTracerProvider(
+			sdktrace.WithBatcher(otlpExporter),
+			sdktrace.WithResource(resources),
+		)
+
+	default:
+		return nil, fmt.Errorf("unsupported trace exporter: %q (supported: none, console, otlp)", exporter)
+	}
+
+	// Set as global default
+	rtrace.SetDefaultTracerProvider(tp)
+
+	return tp, nil
+}
+
+// createResource creates a resource with service information
+func createResource(ctx context.Context, serviceName string) (*resource.Resource, error) {
+	return resource.New(ctx,
+		// Reads OTEL_RESOURCE_ATTRIBUTES and OTEL_SERVICE_NAME
+		resource.WithFromEnv(),
+		// Host Information
+		resource.WithHost(),
+		// Process Information
+		// Resource WithProcessOwner is deliberately omitted because
+		// inside containers where process might run as an arbitrary
+		// uid without a username associated this would fail.
+		resource.WithProcessPID(),
+		resource.WithProcessCommandArgs(),
+		resource.WithProcessExecutableName(),
+		resource.WithProcessExecutablePath(),
+		resource.WithProcessRuntimeDescription(),
+		resource.WithProcessRuntimeName(),
+		resource.WithProcessRuntimeVersion(),
+		// Service attributes
+		resource.WithAttributes(
+			semconv.ServiceName(serviceName),
+			attribute.String("library.language", "go"),
+		),
+	)
+}