add a OT-Go semver

examples/dapperish/dapper.go

@@ -7,5 +7,10 @@ import (
 
 // NewTracer returns a new dapperish Tracer instance.
 func NewTracer(processName string) opentracing.Tracer {
-	return standardtracer.New(NewTrivialRecorder(processName))
+	return standardtracer.New(
+		NewTrivialRecorder(processName),
+		&opentracing.ImplementationID{
+			Name:    "dapperish",
+			Version: "0.1.0",
+		})
 }

ext/tags_test.go

@@ -3,6 +3,7 @@ package ext_test
 import (
 	"testing"
 
+	"github.com/opentracing/opentracing-go"
 	"github.com/opentracing/opentracing-go/ext"
 	"github.com/opentracing/opentracing-go/standardtracer"
 	"github.com/opentracing/opentracing-go/testutils"
@@ -14,7 +15,7 @@ func TestPeerTags(t *testing.T) {
 		t.Fatalf("Invalid PeerService %v", ext.PeerService)
 	}
 	recorder := testutils.NewInMemoryRecorder()
-	tracer := standardtracer.New(recorder)
+	tracer := standardtracer.New(recorder, &opentracing.ImplementationID{})
 	span := tracer.StartTrace("my-trace")
 	ext.PeerService.Add(span, "my-service")
 	ext.PeerHostname.Add(span, "my-hostname")

noop.go

@@ -9,9 +9,13 @@ type noopSpan struct{}
 var (
 	defaultNoopSpan   = noopSpan{}
 	defaultNoopTracer = NoopTracer{}
-	emptyTags         = Tags{}
-	emptyBytes        = []byte{}
-	emptyStringMap    = map[string]string{}
+	noopImplID        = &ImplementationID{
+		Name:    "noop",
+		Version: "1.0.0",
+	}
+	emptyTags      = Tags{}
+	emptyBytes     = []byte{}
+	emptyStringMap = map[string]string{}
 )
 
 const (
@@ -68,3 +72,8 @@ func (n NoopTracer) StartTrace(operationName string) Span {
 func (n NoopTracer) JoinTrace(operationName string, parent interface{}) Span {
 	return defaultNoopSpan
 }
+
+// ImplementationID belongs to the Tracer interface.
+func (n NoopTracer) ImplementationID() *ImplementationID {
+	return noopImplID
+}

standardtracer/spanpropagator_test.go

@@ -14,7 +14,7 @@ import (
 func TestSpanPropagator(t *testing.T) {
 	const op = "test"
 	recorder := testutils.NewInMemoryRecorder()
-	tracer := standardtracer.New(recorder)
+	tracer := standardtracer.New(recorder, &opentracing.ImplementationID{})
 
 	sp := tracer.StartTrace(op)
 	sp.SetTraceAttribute("foo", "bar")

standardtracer/tracer.go

@@ -8,15 +8,17 @@ import (
 
 // New creates and returns a standard Tracer which defers to `recorder` after
 // RawSpans have been assembled.
-func New(recorder SpanRecorder) opentracing.Tracer {
+func New(recorder SpanRecorder, implID *opentracing.ImplementationID) opentracing.Tracer {
 	return &tracerImpl{
 		recorder: recorder,
+		implID:   implID,
 	}
 }
 
 // Implements the `Tracer` interface.
 type tracerImpl struct {
 	recorder SpanRecorder
+	implID   *opentracing.ImplementationID
 }
 
 func (s *tracerImpl) StartTrace(
@@ -58,3 +60,7 @@ func (s *tracerImpl) startSpanGeneric(
 	}
 	return span
 }
+
+func (t *tracerImpl) ImplementationID() *opentracing.ImplementationID {
+	return t.implID
+}

tracer.go

@@ -23,4 +23,21 @@ type Tracer interface {
 	//         SetTag("lucky_number", 42)
 	//
 	StartTrace(operationName string) Span
+
+	// ImplementationID returns information about the OpenTracing
+	// implementation backing the Tracer. The return value should not change
+	// over the life of a particular Tracer instance.
+	ImplementationID() *ImplementationID
+}
+
+// ImplementationID is a simple, extensible struct that describes an
+// OpenTracing implementation.
+type ImplementationID struct {
+	// The (stable) name of the implementation. E.g., "Dapper" or "Zipkin". The
+	// Name should not reflect the host language or platform.
+	Name string
+
+	// Version may take any form, but SemVer (http://semver.org/) is strongly
+	// encouraged.
+	Version string
 }