Do not error on "none" trace exporter value

distro/README.md

@@ -89,8 +89,7 @@ a batch span processor.
   The environment variable values are restricted to the following.
   - `"otlp"`: OTLP gRPC exporter.
   - `"jaeger-thrift-splunk"`: Jaeger thrift exporter.
-  - `"none"`: None, explicitly do not set an exporter. An error is raised by
-    the SDK if no other exporter option is defined.
+  - `"none"`: None, explicitly do not set an exporter.
 
   Any other value will be ignored and the default used instead.
 

distro/config.go

@@ -231,7 +231,7 @@ func WithAccessToken(accessToken string) Option {
 // is not provided. Valid values for this environment variable are "otlp" for
 // an OTLP exporter, and "jaeger-thrift-splunk" for a Splunk specific Jaeger
 // thrift exporter. If this environment variable is set to "none", no exporter
-// is registered and Run will return an error stating this.
+// is registered.
 //
 // By default, an OTLP exporter is used if this is not provided or the
 // OTEL_TRACES_EXPORTER environment variable is not set.

distro/otel.go

@@ -24,7 +24,6 @@ package distro
 
 import (
 	"context"
-	"errors"
 
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/sdk/trace"
@@ -39,7 +38,10 @@ type SDK struct {
 
 // Shutdown stops the SDK and releases any used resources.
 func (s SDK) Shutdown(ctx context.Context) error {
-	return s.shutdownFunc(ctx)
+	if s.shutdownFunc != nil {
+		return s.shutdownFunc(ctx)
+	}
+	return nil
 }
 
 // Run configures the default OpenTelemetry SDK and installs it globally.
@@ -50,8 +52,13 @@ func (s SDK) Shutdown(ctx context.Context) error {
 func Run(opts ...Option) (SDK, error) {
 	c := newConfig(opts...)
 
+	if c.Propagator != nil && c.Propagator != nonePropagator {
+		otel.SetTextMapPropagator(c.Propagator)
+	}
+
 	if c.TraceExporterFunc == nil {
-		return SDK{}, errors.New(`"none" exporter set`)
+		// "none" exporter configured.
+		return SDK{}, nil
 	}
 	exp, err := c.TraceExporterFunc(c.ExportConfig)
 	if err != nil {
@@ -65,10 +72,6 @@ func Run(opts ...Option) (SDK, error) {
 	)
 	otel.SetTracerProvider(traceProvider)
 
-	if c.Propagator != nil && c.Propagator != nonePropagator {
-		otel.SetTextMapPropagator(c.Propagator)
-	}
-
 	return SDK{
 		config: *c,
 		shutdownFunc: func(ctx context.Context) error {

distro/otel_test.go

@@ -547,9 +547,3 @@ func TestInvalidTraceExporter(t *testing.T) {
 	got := <-coll.traceService.requests
 	assert.Equal(t, []string{"application/grpc"}, got.Header.Get("Content-type"))
 }
-
-func TestNoneExporterErrors(t *testing.T) {
-	t.Cleanup(distro.Setenv("OTEL_TRACES_EXPORTER", "none"))
-	_, err := distro.Run()
-	require.Error(t, err, "setting traces exporter to none should error")
-}