add trace context

debug/trace/default.go

@@ -37,7 +37,7 @@ func (t *trace) Read(opts ...ReadOption) ([]*Span, error) {
 	return spans, nil
 }
 
-func (t *trace) Start(ctx context.Context, name string) *Span {
+func (t *trace) Start(ctx context.Context, name string) (context.Context, *Span) {
 	span := &Span{
 		Name:     name,
 		Trace:    uuid.New().String(),
@@ -48,12 +48,12 @@ func (t *trace) Start(ctx context.Context, name string) *Span {
 
 	// return span if no context
 	if ctx == nil {
-		return span
+		return context.Background(), span
 	}
 
 	s, ok := FromContext(ctx)
 	if !ok {
-		return span
+		return ctx, span
 	}
 
 	// set trace id
@@ -62,7 +62,7 @@ func (t *trace) Start(ctx context.Context, name string) *Span {
 	span.Parent = s.Id
 
 	// return the sapn
-	return span
+	return ctx, span
 }
 
 func (t *trace) Finish(s *Span) error {

debug/trace/trace.go

@@ -9,7 +9,7 @@ import (
 // Trace is an interface for distributed tracing
 type Trace interface {
 	// Start a trace
-	Start(ctx context.Context, name string) *Span
+	Start(ctx context.Context, name string) (context.Context, *Span)
 	// Finish the trace
 	Finish(*Span) error
 	// Read the traces