stats/opentelemetry: Introduce Tracing API

experimental/opentelemetry/trace_options.go

@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-// This package is EXPERIMENTAL and may be move to stats/opentelemetry package
-// in a later release.
+// Package opentelemetry is EXPERIMENTAL and may be moved to stats/opentelemetry
+// package in a later release.
 package opentelemetry
 
 import (

stats/opentelemetry/client_tracing.go

@@ -31,7 +31,7 @@
 // It creates a new outgoing carrier which serializes information about this
 // span into gRPC Metadata, if TextMapPropagator is provided in the trace
 // options. if TextMapPropagator is not provided, it returns the context as is.
-func (h *clientStatsHandler) traceTagRPC(ctx context.Context, rti *stats.RPCTagInfo, ai *attemptInfo) (context.Context, *attemptInfo) {
+func (h *clientStatsHandler) traceTagRPC(ctx context.Context, _ *stats.RPCTagInfo, ai *attemptInfo) (context.Context, *attemptInfo) {
 	mn := "Attempt." + strings.Replace(ai.method, "/", ".", -1)
 	tracer := otel.Tracer("grpc-open-telemetry")
 	ctx, span := tracer.Start(ctx, mn)
@@ -45,9 +45,9 @@
 // provided TraceProvider. If TraceProvider is nil, it returns context as is.
 func (h *clientStatsHandler) createCallTraceSpan(ctx context.Context, method string) (context.Context, trace.Span) {
 	if h.options.TraceOptions.TracerProvider == nil {
 		logger.Error("TraceProvider is not provided in trace options")
 		return ctx, nil
 	}
 	mn := strings.Replace(removeLeadingSlash(method), "/", ".", -1)
 	tracer := otel.Tracer("grpc-open-telemetry")
 	ctx, span := tracer.Start(ctx, mn, trace.WithSpanKind(trace.SpanKindClient))

stats/opentelemetry/opentelemetry.go

@@ -66,7 +66,23 @@
 }
 
 func (o *Options) isTracingEnabled() bool {
-	return o.TraceOptions.TextMapPropagator != nil
+	// Check if both TextMapPropagator and TracerProvider are set.
+	isTextMapPropagatorSet := o.TraceOptions.TextMapPropagator != nil
+	isTracerProviderSet := o.TraceOptions.TracerProvider != nil
+
+	// Return false if neither option is set.
+	if !isTextMapPropagatorSet && !isTracerProviderSet {
+		return false
+	}
+
+	// Log an error if one of the options is missing.
+	if isTextMapPropagatorSet != isTracerProviderSet {
+		logger.Error("traceOptions are not set properly: one of TextMapPropagator or TracerProvider is missing.")
+		return false
+	}
+
+	// Both options are set, return true.
+	return true
 }
 
 // MetricsOptions are the metrics options for OpenTelemetry instrumentation.

stats/opentelemetry/server_tracing.go

@@ -33,7 +33,7 @@ import (
 // is set as parent of the new span otherwise new span remains the root span.
 // If TextMapPropagator is not provided in the trace options, it returns context
 // as is.
-func (h *serverStatsHandler) traceTagRPC(ctx context.Context, rti *stats.RPCTagInfo, ai *attemptInfo) (context.Context, *attemptInfo) {
+func (h *serverStatsHandler) traceTagRPC(ctx context.Context, _ *stats.RPCTagInfo, ai *attemptInfo) (context.Context, *attemptInfo) {
 	mn := strings.Replace(ai.method, "/", ".", -1)
 	var span trace.Span
 	tracer := otel.Tracer("grpc-open-telemetry")