Unify trace and metric exporter helpers (#944)

* Adjust Jaeger and Zipkin exporters helper methods

* Update and add tests, examples, various minor improvements

* Update changelog

* Correct the Zipkin example

- wait for the spans to be exported
- rebuild the example

* Zipkin service name as argument

* Rework Jaeger and Zipkin tests

* Include more detailed Changelog

Co-authored-by: ET <evantorrie@users.noreply.github.com>
Co-authored-by: Liz Fong-Jones <lizf@honeycomb.io>
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

CHANGELOG.md

@@ -8,6 +8,11 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 
+### Changed
+
+- Jaeger exporter helpers: added InstallNewPipeline and removed RegisterGlobal option instead. (#944)
+- Zipkin exporter helpers: pipeline methods introduced, new exporter method adjusted. (#944)
+
 ## [0.9.0] - 2020-07-20
 
 ### Added

example/jaeger/main.go

@@ -30,7 +30,7 @@ import (
 // initTracer creates a new trace provider instance and registers it as global trace provider.
 func initTracer() func() {
  // Create and install Jaeger export pipeline
- _, flush, err := jaeger.NewExportPipeline(
+ flush, err := jaeger.InstallNewPipeline(
  jaeger.WithCollectorEndpoint("http://localhost:14268/api/traces"),
  jaeger.WithProcess(jaeger.Process{
  ServiceName: "trace-demo",
@@ -39,7 +39,6 @@ func initTracer() func() {
  kv.Float64("float", 312.23),
  },
  }),
- jaeger.RegisterAsGlobal(),
  jaeger.WithSDK(&sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()}),
  )
  if err != nil {

example/zipkin/main.go

@@ -33,30 +33,20 @@ var logger = log.New(os.Stderr, "zipkin-example", log.Ldate|log.Ltime|log.Llongf
 
 // initTracer creates a new trace provider instance and registers it as global trace provider.
 func initTracer(url string) {
- // Create Zipkin Exporter
- exporter, err := zipkin.NewExporter(
- url,
- "zipkin-example",
- zipkin.WithLogger(logger),
- )
- if err != nil {
- log.Fatal(err)
- }
-
+ // Create Zipkin Exporter and install it as a global tracer.
+ //
  // For demoing purposes, always sample. In a production application, you should
- // configure this to a trace.ProbabilitySampler set at the desired
+ // configure the sampler to a trace.ProbabilitySampler set at the desired
  // probability.
- tp, err := sdktrace.NewProvider(
- sdktrace.WithConfig(sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()}),
- sdktrace.WithBatcher(exporter,
- sdktrace.WithBatchTimeout(5),
- sdktrace.WithMaxExportBatchSize(10),
- ),
+ err := zipkin.InstallNewPipeline(
+ url,
+ "zipkin-test",
+ zipkin.WithLogger(logger),
+ zipkin.WithSDK(&sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()}),
  )
  if err != nil {
  log.Fatal(err)
  }
- global.SetTraceProvider(tp)
 }
 
 func main() {
@@ -73,7 +63,9 @@ func main() {
  bar(ctx)
  <-time.After(6 * time.Millisecond)
  span.End()
- <-time.After(24 * time.Millisecond)
+
+ // Wait for the spans to be exported.
+ <-time.After(5 * time.Second)
 }
 
 func bar(ctx context.Context) {

exporters/trace/jaeger/jaeger.go

@@ -47,10 +47,6 @@ type options struct {
 
  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
-
  Disabled bool
 }
 
@@ -82,14 +78,8 @@ func WithSDK(config *sdktrace.Config) Option {
  }
 }
 
-// RegisterAsGlobal enables the registration of the trace provider of the new pipeline
-// as Global Trace Provider.
-func RegisterAsGlobal() Option {
- return func(o *options) {
- o.RegisterGlobal = true
- }
-}
-
+// WithDisabled option will cause pipeline methods to use
+// a no-op provider
 func WithDisabled(disabled bool) Option {
  return func(o *options) {
  o.Disabled = disabled
@@ -177,13 +167,22 @@ func NewExportPipeline(endpointOption EndpointOption, opts ...Option) (apitrace.
  if exporter.o.Config != nil {
  tp.ApplyConfig(*exporter.o.Config)
  }
- if exporter.o.RegisterGlobal {
- global.SetTraceProvider(tp)
- }
 
  return tp, exporter.Flush, nil
 }
 
+// InstallNewPipeline instantiates a NewExportPipeline with the
+// recommended configuration and registers it globally.
+func InstallNewPipeline(endpointOption EndpointOption, opts ...Option) (func(), error) {
+ tp, flushFn, err := NewExportPipeline(endpointOption, opts...)
+ if err != nil {
+ return nil, err
+ }
+
+ global.SetTraceProvider(tp)
+ return flushFn, nil
+}
+
 // Process contains the information exported to jaeger about the source
 // of the trace data.
 type Process struct {