fix(otel)!: do not use a global client

Signed-off-by: Adphi <philippe.adrien.nousse@gmail.com>

example/example.go

@@ -41,15 +41,15 @@ func run(ctx context.Context, opts ...service.Option) {
 	done := make(chan struct{})
 	ready := make(chan struct{})
 
-	otel.Configure(
+	p := otel.Configure(
-		// otel.WithDSN("http://127.0.0.1:4318"),
+		ctx,
 		otel.WithServiceName(name),
 		otel.WithServiceVersion(version),
 		otel.WithDeploymentEnvironment("tests"),
 		otel.WithTraceSampler(sdktrace.AlwaysSample()),
 		otel.WithMetricPrometheusBridge(),
 	)
-	defer otel.Shutdown(context.WithoutCancel(ctx))
+	defer p.Shutdown(ctx)
 
 	address := "0.0.0.0:9991"
 

otel/client.go

@@ -15,6 +15,17 @@ import (
 
 const dummySpanName = "__dummy__"
 
+type Provider interface {
+	TraceURL(span trace.Span) string
+	ReportError(ctx context.Context, err error, opts ...trace.EventOption)
+	ReportPanic(ctx context.Context, val any)
+	Shutdown(ctx context.Context) error
+	ForceFlush(ctx context.Context) error
+	TracerProvider() *sdktrace.TracerProvider
+	MeterProvider() *sdkmetric.MeterProvider
+	LoggerProvider() *sdklog.LoggerProvider
+}
+
 type client struct {
 	dsn    *DSN
 	tracer trace.Tracer
@@ -32,6 +43,7 @@ func newClient(dsn *DSN) *client {
 }
 
 func (c *client) Shutdown(ctx context.Context) (lastErr error) {
+	ctx = context.WithoutCancel(ctx)
 	if c.tp != nil {
 		if err := c.tp.Shutdown(ctx); err != nil {
 			lastErr = err
@@ -99,6 +111,30 @@ func (c *client) ReportPanic(ctx context.Context, val any) {
 	}
 }
 
+func (c *client) TracerProvider() *sdktrace.TracerProvider {
+	if c.tp == nil {
+		return sdktrace.NewTracerProvider(
+			sdktrace.WithSampler(sdktrace.AlwaysSample()),
+			sdktrace.WithIDGenerator(newIDGenerator()),
+		)
+	}
+	return c.tp
+}
+
+func (c *client) MeterProvider() *sdkmetric.MeterProvider {
+	if c.mp == nil {
+		return sdkmetric.NewMeterProvider()
+	}
+	return c.mp
+}
+
+func (c *client) LoggerProvider() *sdklog.LoggerProvider {
+	if c.lp == nil {
+		return sdklog.NewLoggerProvider()
+	}
+	return c.lp
+}
+
 func (c *client) reportPanic(ctx context.Context, val interface{}) {
 	span := trace.SpanFromContext(ctx)
 	if !span.IsRecording() {

otel/config.go

@@ -12,6 +12,8 @@ import (
 	"go.opentelemetry.io/otel/sdk/resource"
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 	semconv "go.opentelemetry.io/otel/semconv/v1.21.0"
+
+	"go.linka.cloud/grpc-toolkit/logger"
 )
 
 type config struct {
@@ -62,7 +64,8 @@ func newConfig(opts []Option) *config {
 	return conf
 }
 
-func (conf *config) newResource() *resource.Resource {
+func (conf *config) newResource(ctx context.Context) *resource.Resource {
+	log := logger.C(ctx)
 	if conf.resource != nil {
 		if len(conf.resourceAttributes) > 0 {
 			log.Warnf("WithResource overrides WithResourceAttributes (discarding %v)",
@@ -75,8 +78,6 @@ func (conf *config) newResource() *resource.Resource {
 		return conf.resource
 	}
 
-	ctx := context.TODO()
-
 	res, err := resource.New(ctx,
 		resource.WithFromEnv(),
 		resource.WithTelemetrySDK(),

otel/logging.go

@@ -7,11 +7,14 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp"
 	"go.opentelemetry.io/otel/log/global"
 	sdklog "go.opentelemetry.io/otel/sdk/log"
+
+	"go.linka.cloud/grpc-toolkit/logger"
 )
 
 func configureLogging(ctx context.Context, conf *config) *sdklog.LoggerProvider {
+	log := logger.C(ctx)
 	var opts []sdklog.LoggerProviderOption
-	if res := conf.newResource(); res != nil {
+	if res := conf.newResource(ctx); res != nil {
 		opts = append(opts, sdklog.WithResource(res))
 	}
 

otel/metrics.go

@@ -10,11 +10,14 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp"
 	sdkmetric "go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
+
+	"go.linka.cloud/grpc-toolkit/logger"
 )
 
 func configureMetrics(ctx context.Context, conf *config) *sdkmetric.MeterProvider {
+	log := logger.C(ctx)
 	opts := conf.metricOptions
-	if res := conf.newResource(); res != nil {
+	if res := conf.newResource(ctx); res != nil {
 		opts = append(opts, sdkmetric.WithResource(res))
 	}
 

otel/otel.go

@@ -4,17 +4,14 @@ import (
 	"context"
 	"os"
 	"strings"
-	"sync/atomic"
 
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/propagation"
-	sdktrace "go.opentelemetry.io/otel/sdk/trace"
-	"go.opentelemetry.io/otel/trace"
 
 	"go.linka.cloud/grpc-toolkit/logger"
 )
 
-var log = logger.StandardLogger().WithField("name", "otel")
+var dummy = newClient(&DSN{})
 
 // Configure configures OpenTelemetry.
 // By default, it:
@@ -23,27 +20,28 @@ var log = logger.StandardLogger().WithField("name", "otel")
 //   - sets tracecontext + baggage composite context propagator.
 //
 // You can use OTEL_DISABLED env var to completely skip otel configuration.
-func Configure(opts ...Option) {
+func Configure(ctx context.Context, opts ...Option) Provider {
 	if _, ok := os.LookupEnv("OTEL_DISABLED"); ok {
-		return
+		return dummy
 	}
 
-	ctx := context.TODO()
+	log := logger.C(ctx)
+
 	conf := newConfig(opts)
 
 	if !conf.tracingEnabled && !conf.metricsEnabled && !conf.loggingEnabled {
-		return
+		return dummy
 	}
 
 	if len(conf.dsn) == 0 {
 		log.Warn("no DSN provided (otel-go is disabled)")
-		return
+		return dummy
 	}
 
 	dsn, err := ParseDSN(conf.dsn[0])
 	if err != nil {
 		log.Warnf("invalid DSN: %s (otel is disabled)", err)
-		return
+		return dummy
 	}
 
 	if strings.HasSuffix(dsn.Host, ":4318") {
@@ -63,7 +61,7 @@ func Configure(opts ...Option) {
 		client.lp = configureLogging(ctx, conf)
 	}
 
-	atomicClient.Store(client)
+	return client
 }
 
 func configurePropagator(conf *config) {
@@ -76,47 +74,3 @@ func configurePropagator(conf *config) {
 	}
 	otel.SetTextMapPropagator(textMapPropagator)
 }
-
-// ------------------------------------------------------------------------------
-
-var (
-	fallbackClient = newClient(&DSN{})
-	atomicClient   atomic.Value
-)
-
-func activeClient() *client {
-	v := atomicClient.Load()
-	if v == nil {
-		return fallbackClient
-	}
-	return v.(*client)
-}
-
-func TraceURL(span trace.Span) string {
-	return activeClient().TraceURL(span)
-}
-
-func ReportError(ctx context.Context, err error, opts ...trace.EventOption) {
-	activeClient().ReportError(ctx, err, opts...)
-}
-
-func ReportPanic(ctx context.Context, val any) {
-	activeClient().ReportPanic(ctx, val)
-}
-
-func Shutdown(ctx context.Context) error {
-	return activeClient().Shutdown(ctx)
-}
-
-func ForceFlush(ctx context.Context) error {
-	return activeClient().ForceFlush(ctx)
-}
-
-func TracerProvider() *sdktrace.TracerProvider {
-	return activeClient().tp
-}
-
-// SetLogger sets the logger to the given one.
-func SetLogger(logger logger.Logger) {
-	log = logger
-}

otel/tracing.go

@@ -15,15 +15,18 @@ import (
 	"go.opentelemetry.io/otel/exporters/stdout/stdouttrace"
 	sdktrace "go.opentelemetry.io/otel/sdk/trace"
 	"go.opentelemetry.io/otel/trace"
+
+	"go.linka.cloud/grpc-toolkit/logger"
 )
 
 func configureTracing(ctx context.Context, conf *config) *sdktrace.TracerProvider {
+	log := logger.C(ctx)
 	provider := conf.tracerProvider
 	if provider == nil {
 		var opts []sdktrace.TracerProviderOption
 
 		opts = append(opts, sdktrace.WithIDGenerator(newIDGenerator()))
-		if res := conf.newResource(); res != nil {
+		if res := conf.newResource(ctx); res != nil {
 			opts = append(opts, sdktrace.WithResource(res))
 		}
 		if conf.traceSampler != nil {