[service] add level for trace configuration

This allows users to configure a Noop TracerProvider if needed. Note that this
configuration option breaks the zpages extension, which relies on a SDK implementation.

Signed-off-by: Alex Boten <[email protected]>

.chloggen/codeboten_trace-level.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: service
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Adds `level` configuration option to `service::telemetry::trace` to allow users to disable the default TracerProvider"
+
+# One or more tracking issues or pull requests related to the change
+issues: [10892]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext: "This replaces the feature gate `service.noopTracerProvider` introduced in v0.107.0"
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

internal/globalgates/globalgates.go

@@ -28,4 +28,5 @@ var DisableOpenCensusBridge = featuregate.GlobalRegistry().MustRegister("service
 var NoopTracerProvider = featuregate.GlobalRegistry().MustRegister("service.noopTracerProvider",
 	featuregate.StageAlpha,
 	featuregate.WithRegisterFromVersion("v0.107.0"),
+	featuregate.WithRegisterToVersion("v0.109.0"),
 	featuregate.WithRegisterDescription("Sets a Noop OpenTelemetry TracerProvider to reduce memory allocations. This featuregate is incompatible with the zPages extension."))

service/telemetry/config.go

@@ -130,6 +130,10 @@ type MetricsConfig struct {
 // TracesConfig exposes the common Telemetry configuration for collector's internal spans.
 // Experimental: *NOTE* this structure is subject to change or removal in the future.
 type TracesConfig struct {
+	// Level configures whether spans are emitted or not, the possible values are:
+	//  - "none" indicates that no tracing data should be collected;
+	//  - "basic" is the recommended and covers the basics of the service telemetry.
+	Level configtelemetry.Level `mapstructure:"level"`
 	// Propagators is a list of TextMapPropagators from the supported propagators list. Currently,
 	// tracecontext and  b3 are supported. By default, the value is set to empty list and
 	// context propagation is disabled.

service/telemetry/tracer.go

@@ -15,6 +15,7 @@ import (
 	"go.opentelemetry.io/otel/trace"
 	"go.opentelemetry.io/otel/trace/noop"
 
+	"go.opentelemetry.io/collector/config/configtelemetry"
 	"go.opentelemetry.io/collector/internal/globalgates"
 )
 
@@ -48,9 +49,10 @@ func attributes(set Settings, cfg Config) map[string]interface{} {
 
 // New creates a new Telemetry from Config.
 func newTracerProvider(ctx context.Context, set Settings, cfg Config) (trace.TracerProvider, error) {
-	if globalgates.NoopTracerProvider.IsEnabled() {
+	if globalgates.NoopTracerProvider.IsEnabled() || cfg.Traces.Level == configtelemetry.LevelNone {
 		return noop.NewTracerProvider(), nil
 	}
+
 	sch := semconv.SchemaURL
 	res := config.Resource{
 		SchemaUrl:  &sch,

service/telemetry/tracer_test.go

@@ -12,6 +12,7 @@ import (
 	"go.opentelemetry.io/otel/trace/noop"
 
 	"go.opentelemetry.io/collector/component"
+	"go.opentelemetry.io/collector/config/configtelemetry"
 	"go.opentelemetry.io/collector/featuregate"
 	"go.opentelemetry.io/collector/internal/globalgates"
 	"go.opentelemetry.io/collector/service/telemetry/internal"
@@ -65,11 +66,22 @@ func TestNewTracerProvider(t *testing.T) {
 	tests := []struct {
 		name               string
 		wantTracerProvider any
-		noopTracer         bool
+		noopTracerGate     bool
+		cfg                Config
 	}{
 		{
-			name:               "noop tracer provider",
-			noopTracer:         true,
+			name: "trace level none",
+			cfg: Config{
+				Traces: TracesConfig{
+					Level: configtelemetry.LevelNone,
+				},
+			},
+			wantTracerProvider: noop.TracerProvider{},
+		},
+		{
+			name:               "noop tracer feature gate",
+			cfg:                Config{},
+			noopTracerGate:     true,
 			wantTracerProvider: noop.TracerProvider{},
 		},
 		{
@@ -80,13 +92,12 @@ func TestNewTracerProvider(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			previousValue := globalgates.NoopTracerProvider.IsEnabled()
-			err := featuregate.GlobalRegistry().Set(globalgates.NoopTracerProvider.ID(), tt.noopTracer)
-			require.NoError(t, err)
+			// expect error due to deprecated flag
+			require.NoError(t, featuregate.GlobalRegistry().Set(globalgates.NoopTracerProvider.ID(), tt.noopTracerGate))
 			defer func() {
-				err = featuregate.GlobalRegistry().Set(globalgates.NoopTracerProvider.ID(), previousValue)
-				require.NoError(t, err)
+				require.NoError(t, featuregate.GlobalRegistry().Set(globalgates.NoopTracerProvider.ID(), previousValue))
 			}()
-			provider, err := newTracerProvider(context.TODO(), internal.Settings{}, Config{})
+			provider, err := newTracerProvider(context.TODO(), internal.Settings{}, tt.cfg)
 			require.NoError(t, err)
 			require.IsType(t, tt.wantTracerProvider, provider)
 		})