[tracing] add simplified export pipeline setup for Jaeger (#459)

* add simplified export pipeline setup for Jaeger

* add With* options to configure SDK options.

* add test for WithRegistration and WithSDK

* rename Registeration with RegisterGlobal

* rename WithRegistration to RegisterAsGlobal

Co-authored-by: rahulpa <rahulpa@google.com>
Co-authored-by: Joshua MacDonald <jmacd@users.noreply.github.com>

example/jaeger/main.go

@@ -30,8 +30,8 @@ import (
 
 // initTracer creates a new trace provider instance and registers it as global trace provider.
 func initTracer() func() {
-	// Create Jaeger Exporter
-	exporter, err := jaeger.NewExporter(
+	// Create and install Jaeger export pipeline
+	_, flush, err := jaeger.NewExportPipeline(
 		jaeger.WithCollectorEndpoint("http://localhost:14268/api/traces"),
 		jaeger.WithProcess(jaeger.Process{
 			ServiceName: "trace-demo",
@@ -40,23 +40,15 @@ func initTracer() func() {
 				key.Float64("float", 312.23),
 			},
 		}),
+		jaeger.RegisterAsGlobal(),
+		jaeger.WithSDK(&sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()}),
 	)
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	// For demoing purposes, always sample. In a production application, you should
-	// configure this to a trace.ProbabilitySampler set at the desired
-	// probability.
-	tp, err := sdktrace.NewProvider(
-		sdktrace.WithConfig(sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()}),
-		sdktrace.WithSyncer(exporter))
-	if err != nil {
-		log.Fatal(err)
-	}
-	global.SetTraceProvider(tp)
 	return func() {
-		exporter.Flush()
+		flush()
 	}
 }
 

exporters/trace/jaeger/jaeger.go

@@ -23,8 +23,10 @@ import (
 	"google.golang.org/grpc/codes"
 
 	"go.opentelemetry.io/otel/api/core"
+	"go.opentelemetry.io/otel/api/global"
 	gen "go.opentelemetry.io/otel/exporters/trace/jaeger/internal/gen-go/jaeger"
 	export "go.opentelemetry.io/otel/sdk/export/trace"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 )
 
 const defaultServiceName = "OpenTelemetry"
@@ -43,6 +45,12 @@ type options struct {
 
 	//BufferMaxCount defines the total number of traces that can be buffered in memory
 	BufferMaxCount int
+
+	Config *sdktrace.Config
+
+	// RegisterGlobal is set to true if the trace provider of the new pipeline should be
+	// registered as Global Trace Provider
+	RegisterGlobal bool
 }
 
 // WithOnError sets the hook to be called when there is
@@ -68,9 +76,24 @@ func WithBufferMaxCount(bufferMaxCount int) func(o *options) {
 	}
 }
 
-// NewExporter returns a trace.Exporter implementation that exports
+// WithSDK sets the SDK config for the exporter pipeline.
+func WithSDK(config *sdktrace.Config) func(o *options) {
+	return func(o *options) {
+		o.Config = config
+	}
+}
+
+// RegisterAsGlobal enables the registration of the trace provider of the new pipeline
+// as Global Trace Provider.
+func RegisterAsGlobal() func(o *options) {
+	return func(o *options) {
+		o.RegisterGlobal = true
+	}
+}
+
+// NewRawExporter returns a trace.Exporter implementation that exports
 // the collected spans to Jaeger.
-func NewExporter(endpointOption EndpointOption, opts ...Option) (*Exporter, error) {
+func NewRawExporter(endpointOption EndpointOption, opts ...Option) (*Exporter, error) {
 	uploader, err := endpointOption()
 	if err != nil {
 		return nil, err
@@ -105,6 +128,7 @@ func NewExporter(endpointOption EndpointOption, opts ...Option) (*Exporter, erro
 			ServiceName: service,
 			Tags:        tags,
 		},
+		o: o,
 	}
 	bundler := bundler.NewBundler((*gen.Span)(nil), func(bundle interface{}) {
 		if err := e.upload(bundle.([]*gen.Span)); err != nil {
@@ -123,6 +147,28 @@ func NewExporter(endpointOption EndpointOption, opts ...Option) (*Exporter, erro
 	return e, nil
 }
 
+// NewExportPipeline sets up a complete export pipeline
+// with the recommended setup for trace provider
+func NewExportPipeline(endpointOption EndpointOption, opts ...Option) (*sdktrace.Provider, func(), error) {
+	exporter, err := NewRawExporter(endpointOption, opts...)
+	if err != nil {
+		return nil, nil, err
+	}
+	syncer := sdktrace.WithSyncer(exporter)
+	tp, err := sdktrace.NewProvider(syncer)
+	if err != nil {
+		return nil, nil, err
+	}
+	if exporter.o.Config != nil {
+		tp.ApplyConfig(*exporter.o.Config)
+	}
+	if exporter.o.RegisterGlobal {
+		global.SetTraceProvider(tp)
+	}
+
+	return tp, exporter.Flush, nil
+}
+
 // Process contains the information exported to jaeger about the source
 // of the trace data.
 type Process struct {
@@ -138,6 +184,7 @@ type Exporter struct {
 	process  *gen.Process
 	bundler  *bundler.Bundler
 	uploader batchUploader
+	o        options
 }
 
 var _ export.SpanSyncer = (*Exporter)(nil)

exporters/trace/jaeger/jaeger_test.go

@@ -37,7 +37,54 @@ import (
 	export "go.opentelemetry.io/otel/sdk/export/trace"
 )
 
-func TestNewExporter(t *testing.T) {
+func TestNewExporterPipelineWithRegistration(t *testing.T) {
+	tp, fn, err := NewExportPipeline(
+		WithCollectorEndpoint("http://localhost:14268/api/traces"),
+		RegisterAsGlobal(),
+	)
+	defer fn()
+	assert.NoError(t, err)
+	assert.Same(t, tp, global.TraceProvider())
+}
+
+func TestNewExporterPipelineWithoutRegistration(t *testing.T) {
+	tp, fn, err := NewExportPipeline(
+		WithCollectorEndpoint("http://localhost:14268/api/traces"),
+	)
+	defer fn()
+	assert.NoError(t, err)
+	assert.NotEqual(t, tp, global.TraceProvider())
+}
+
+func TestNewExporterPipelineWithSDK(t *testing.T) {
+	tp, fn, err := NewExportPipeline(
+		WithCollectorEndpoint("http://localhost:14268/api/traces"),
+		WithSDK(&sdktrace.Config{
+			DefaultSampler: sdktrace.AlwaysSample(),
+		}),
+	)
+	defer fn()
+	assert.NoError(t, err)
+	_, span := tp.Tracer("jaeger test").Start(context.Background(), "always-on")
+	spanCtx := span.SpanContext()
+	assert.True(t, spanCtx.IsSampled())
+	span.End()
+
+	tp2, fn, err := NewExportPipeline(
+		WithCollectorEndpoint("http://localhost:14268/api/traces"),
+		WithSDK(&sdktrace.Config{
+			DefaultSampler: sdktrace.NeverSample(),
+		}),
+	)
+	defer fn()
+	assert.NoError(t, err)
+	_, span2 := tp2.Tracer("jaeger test").Start(context.Background(), "never")
+	span2Ctx := span2.SpanContext()
+	assert.False(t, span2Ctx.IsSampled())
+	span2.End()
+}
+
+func TestNewRawExporter(t *testing.T) {
 	const (
 		collectorEndpoint = "http://localhost"
 		serviceName       = "test-service"
@@ -45,7 +92,7 @@ func TestNewExporter(t *testing.T) {
 		tagVal            = "val"
 	)
 	// Create Jaeger Exporter
-	exp, err := NewExporter(
+	exp, err := NewRawExporter(
 		WithCollectorEndpoint(collectorEndpoint),
 		WithProcess(Process{
 			ServiceName: serviceName,
@@ -60,8 +107,8 @@ func TestNewExporter(t *testing.T) {
 	assert.Len(t, exp.process.Tags, 1)
 }
 
-func TestNewExporterShouldFailIfCollectorEndpointEmpty(t *testing.T) {
-	_, err := NewExporter(
+func TestNewRawExporterShouldFailIfCollectorEndpointEmpty(t *testing.T) {
+	_, err := NewRawExporter(
 		WithCollectorEndpoint(""),
 	)
 
@@ -92,7 +139,7 @@ func TestExporter_ExportSpan(t *testing.T) {
 		tagVal      = "val"
 	)
 	// Create Jaeger Exporter
-	exp, err := NewExporter(
+	exp, err := NewRawExporter(
 		withTestCollectorEndpoint(),
 		WithProcess(Process{
 			ServiceName: serviceName,
@@ -121,24 +168,24 @@ func TestExporter_ExportSpan(t *testing.T) {
 	assert.True(t, len(tc.spansUploaded) == 1)
 }
 
-func TestNewExporterWithAgentEndpoint(t *testing.T) {
+func TestNewRawExporterWithAgentEndpoint(t *testing.T) {
 	const agentEndpoint = "localhost:6831"
 	// Create Jaeger Exporter
-	_, err := NewExporter(
+	_, err := NewRawExporter(
 		WithAgentEndpoint(agentEndpoint),
 	)
 	assert.NoError(t, err)
 }
 
-func TestNewExporterWithAgentShouldFailIfEndpointInvalid(t *testing.T) {
+func TestNewRawExporterWithAgentShouldFailIfEndpointInvalid(t *testing.T) {
 	//empty
-	_, err := NewExporter(
+	_, err := NewRawExporter(
 		WithAgentEndpoint(""),
 	)
 	assert.Error(t, err)
 
 	//invalid endpoint addr
-	_, err = NewExporter(
+	_, err = NewRawExporter(
 		WithAgentEndpoint("http://localhost"),
 	)
 	assert.Error(t, err)