Add dynamic elps filtering option

opttrace/opttrace.go

@@ -16,7 +16,10 @@ import (
 	"go.opentelemetry.io/otel/trace/noop"
 )
 
-const tracerName = "opttrace"
+const (
+	tracerName                     = "opttrace"
+	disableElpsFilteringTraceState = "disable_elps_filtering"
+)
 
 var noopTracerProvider = noop.NewTracerProvider()
 
@@ -145,13 +148,37 @@ func otlpExporter(ctx context.Context, traceURI string) (*otlptrace.Exporter, er
 	return otlptracegrpc.New(ctx, otlpOpts...)
 }
 
+// TraceContextWithoutELPSFilter takes adds trace state into the propagated
+// context to signify that elps filtering should be disabled for the request.
+// NOTE: this results in very large traces.
+func TraceContextWithoutELPSFilter(ctx context.Context) (context.Context, error) {
+	spanCtx := trace.SpanContextFromContext(ctx)
+	if !spanCtx.IsValid() {
+		return ctx, fmt.Errorf("not trace context")
+	}
+
+	traceState := spanCtx.TraceState()
+	if value := traceState.Get(disableElpsFilteringTraceState); value == "true" {
+		return ctx, nil
+	}
+
+	newTraceState, err := traceState.Insert(disableElpsFilteringTraceState, "true")
+	if err != nil {
+		return ctx, fmt.Errorf("state insert: %w", err)
+	}
+
+	newSpanCtx := spanCtx.WithTraceState(newTraceState)
+	return trace.ContextWithSpanContext(ctx, newSpanCtx), nil
+}
+
 // Span creates a new trace span and returns the supplied context with span
 // added.  The returned span must be ended to avoid leaking resources.
 func (t Tracer) Span(ctx context.Context, spanName string, opts ...trace.SpanStartOption) (context.Context, trace.Span) {
 	if t.exportTP == nil {
 		return noopTracerProvider.Tracer(tracerName).Start(ctx, spanName, opts...)
 	}
-	return t.exportTP.Tracer(tracerName).Start(ctx, spanName, opts...)
+	tracer := t.exportTP.Tracer(tracerName)
+	return tracer.Start(ctx, spanName, opts...)
 }
 
 // Shutdown releases all resources allocated by the tracing provider.

oracle/oracle.go

@@ -21,6 +21,7 @@ import (
 	"github.com/luthersystems/svc/grpclogging"
 	"github.com/luthersystems/svc/opttrace"
 	"github.com/sirupsen/logrus"
+	"go.opentelemetry.io/otel/trace"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -374,6 +375,17 @@ func (orc *Oracle) close() error {
 	return orc.phylum.Close()
 }
 
+// TraceContextDefer is a fuction that must be called to stop the span.
+type TraceContextDefer func()
+
+// TraceContext adds tracing to a request context.
+func (orc *Oracle) TraceContext(ctx context.Context, spanName string, opts ...trace.SpanStartOption) (context.Context, TraceContextDefer) {
+	ctx, span := orc.tracer.Span(ctx, spanName, opts...)
+	return ctx, func() {
+		span.End()
+	}
+}
+
 // Call calls the phylum.
 func Call[K proto.Message, R proto.Message](s *Oracle, ctx context.Context, methodName string, req K, resp R, config ...shiroclient.Config) (R, error) {
 	configs := s.txConfigs(ctx)