Setup the correct meter provider if telemetry.useOtelForInternalMetri…

…cs featuregate enabled

This PR also removes the set of the global MeterProvider, similarly with open-telemetry#5138.

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

service/collector.go

@@ -106,6 +106,10 @@ func New(set CollectorSettings) (*Collector, error) {
 	return &Collector{
 		logger: zap.NewNop(), // Set a Nop logger as a place holder until a logger is created based on configuration
 
+		tracerProvider:    trace.NewNoopTracerProvider(),
+		meterProvider:     nonrecording.NewNoopMeterProvider(),
+		asyncErrorChannel: make(chan error),
+
 		set:          set,
 		state:        int32(Starting),
 		shutdownChan: make(chan struct{}),
@@ -215,6 +219,13 @@ func (col *Collector) setupConfigurationComponents(ctx context.Context) error {
 		return err
 	}
 
+	// TODO: This should be part of the service initialization, which should be responsible to create TelemetrySettings.
+	// For the moment happens here, since it needs service.Config and Logger.
+	// It is called once because that is how it is implemented using sync.Once.
+	if err = collectorTelemetry.init(col); err != nil {
+		return err
+	}
+
 	if err = col.service.Start(ctx); err != nil {
 		return err
 	}
@@ -230,20 +241,11 @@ func (col *Collector) Run(ctx context.Context) error {
 		sdktrace.WithSampler(internal.AlwaysRecord()),
 		sdktrace.WithSpanProcessor(col.zPagesSpanProcessor))
 
-	col.meterProvider = nonrecording.NewNoopMeterProvider()
-
-	col.asyncErrorChannel = make(chan error)
-
 	if err := col.setupConfigurationComponents(ctx); err != nil {
 		col.setCollectorState(Closed)
 		return err
 	}
 
-	if err := collectorTelemetry.init(col); err != nil {
-		col.setCollectorState(Closed)
-		return err
-	}
-
 	col.logger.Info("Starting "+col.set.BuildInfo.Command+"...",
 		zap.String("Version", col.set.BuildInfo.Version),
 		zap.Int("NumCPU", runtime.NumCPU()),

service/telemetry.go

@@ -25,7 +25,6 @@ import (
 	"github.com/google/uuid"
 	"go.opencensus.io/stats/view"
 	otelprometheus "go.opentelemetry.io/otel/exporters/prometheus"
-	"go.opentelemetry.io/otel/metric/global"
 	"go.opentelemetry.io/otel/sdk/metric/aggregator/histogram"
 	controller "go.opentelemetry.io/otel/sdk/metric/controller/basic"
 	"go.opentelemetry.io/otel/sdk/metric/export/aggregation"
@@ -113,7 +112,7 @@ func (tel *colTelemetry) initOnce(col *Collector) error {
 
 	var pe http.Handler
 	if featuregate.IsEnabled(useOtelForInternalMetricsfeatureGateID) {
-		otelHandler, err := tel.initOpenTelemetry()
+		otelHandler, err := tel.initOpenTelemetry(col)
 		if err != nil {
 			return err
 		}
@@ -193,7 +192,7 @@ func (tel *colTelemetry) initOpenCensus(col *Collector, instanceID string) (http
 	return pe, nil
 }
 
-func (tel *colTelemetry) initOpenTelemetry() (http.Handler, error) {
+func (tel *colTelemetry) initOpenTelemetry(col *Collector) (http.Handler, error) {
 	config := otelprometheus.Config{}
 	c := controller.New(
 		processor.NewFactory(
@@ -210,7 +209,7 @@ func (tel *colTelemetry) initOpenTelemetry() (http.Handler, error) {
 		return nil, err
 	}
 
-	global.SetMeterProvider(pe.MeterProvider())
+	col.meterProvider = pe.MeterProvider()
 	return pe, err
 }