update stdout trace with resource. (#558)

* update stdout trace with resource.

* convert resource to span attributes.

* remove resource reference after converting to Span Attributes.

Author: rghetia

example/basic/main.go

@@ -18,6 +18,7 @@ import (
 	"context"
 	"log"
 
+	"go.opentelemetry.io/otel/api/core"
 	"go.opentelemetry.io/otel/api/correlation"
 	"go.opentelemetry.io/otel/api/global"
 	"go.opentelemetry.io/otel/api/key"
@@ -45,7 +46,8 @@ func initTracer() {
 		return
 	}
 	tp, err := sdktrace.NewProvider(sdktrace.WithSyncer(exp),
-		sdktrace.WithConfig(sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()}))
+		sdktrace.WithConfig(sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()}),
+		sdktrace.WithResourceAttributes(core.Key("rk1").String("rv11"), core.Key("rk2").Int64(5)))
 	if err != nil {
 		log.Panicf("failed to initialize trace provider %v", err)
 	}

exporters/trace/stdout/stdout.go

@@ -51,6 +51,18 @@ func NewExporter(o Options) (*Exporter, error) {
 
 // ExportSpan writes a SpanData in json format to stdout.
 func (e *Exporter) ExportSpan(ctx context.Context, data *export.SpanData) {
+	if data.Resource != nil {
+		dataCopy := *data
+		dataCopy.Attributes = append(data.Attributes, data.Resource.Attributes()...)
+		dataCopy.Resource = nil
+		e.exportSpan(ctx, &dataCopy)
+	} else {
+		e.exportSpan(ctx, data)
+	}
+}
+
+// ExportSpan writes a SpanData in json format to stdout.
+func (e *Exporter) exportSpan(ctx context.Context, data *export.SpanData) {
 	var jsonSpan []byte
 	var err error
 	if e.pretty {

exporters/trace/stdout/stdout_test.go

@@ -27,6 +27,7 @@ import (
 	"go.opentelemetry.io/otel/api/key"
 	"go.opentelemetry.io/otel/api/trace"
 	export "go.opentelemetry.io/otel/sdk/export/trace"
+	"go.opentelemetry.io/otel/sdk/resource"
 )
 
 func TestExporter_ExportSpan(t *testing.T) {
@@ -43,6 +44,7 @@ func TestExporter_ExportSpan(t *testing.T) {
 	spanID, _ := core.SpanIDFromHex("0102030405060708")
 	keyValue := "value"
 	doubleValue := 123.456
+	resource := resource.New(core.Key("rk1").String("rv11"))
 
 	testSpan := &export.SpanData{
 		SpanContext: core.SpanContext{
@@ -63,6 +65,7 @@ func TestExporter_ExportSpan(t *testing.T) {
 		SpanKind:      trace.SpanKindInternal,
 		StatusCode:    codes.Unknown,
 		StatusMessage: "interesting",
+		Resource:      resource,
 	}
 	ex.ExportSpan(context.Background(), testSpan)
 
@@ -85,6 +88,10 @@ func TestExporter_ExportSpan(t *testing.T) {
 		`{` +
 		`"Key":"double",` +
 		`"Value":{"Type":"FLOAT64","Value":123.456}` +
+		`},` +
+		`{` +
+		`"Key":"rk1",` +
+		`"Value":{"Type":"STRING","Value":"rv11"}` +
 		`}` +
 		`],` +
 		`"MessageEvents":[` +