micro: rewrite options to support multiple building blocks

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

tracer/noop.go

@@ -6,6 +6,10 @@ type noopTracer struct {
 	opts Options
 }
 
+func (n *noopTracer) Name() string {
+	return n.opts.Name
+}
+
 // Init initilize tracer
 func (n *noopTracer) Init(opts ...Option) error {
 	for _, o := range opts {
@@ -19,6 +23,11 @@ func (n *noopTracer) Start(ctx context.Context, name string) (context.Context, *
 	return nil, nil
 }
 
+// Lookup get span from context
+func (n *noopTracer) Lookup(ctx context.Context) (*Span, error) {
+	return nil, nil
+}
+
 // Finish finishes span
 func (n *noopTracer) Finish(*Span) error {
 	return nil

tracer/options.go

@@ -9,6 +9,7 @@ var (
 
 // Options struct
 type Options struct {
+	Name string
 	// Logger is the logger for messages
 	Logger logger.Logger
 	// Size is the size of ring buffer

tracer/tracer.go

@@ -15,10 +15,14 @@ var (
 
 // Tracer is an interface for distributed tracing
 type Tracer interface {
+	Name() string
+	Init(...Option) error
 	// Start a trace
 	Start(ctx context.Context, name string) (context.Context, *Span)
 	// Finish the trace
 	Finish(*Span) error
+	// Lookup get span from context
+	Lookup(ctx context.Context) (*Span, error)
 	// Read the traces
 	Read(...ReadOption) ([]*Span, error)
 }