add OTEL trace for clusterpedia-apiserver

cmd/apiserver/app/apiserver.go

@@ -14,9 +14,12 @@ import (
 	"k8s.io/component-base/logs"
 	logsapi "k8s.io/component-base/logs/api/v1"
 	"k8s.io/component-base/term"
+	"k8s.io/klog/v2"
 
 	"github.com/clusterpedia-io/clusterpedia/cmd/apiserver/app/options"
+	"github.com/clusterpedia-io/clusterpedia/pkg/constants"
 	"github.com/clusterpedia-io/clusterpedia/pkg/storage"
+	"github.com/clusterpedia-io/clusterpedia/pkg/utils/trace"
 	"github.com/clusterpedia-io/clusterpedia/pkg/version/verflag"
 )
 
@@ -45,6 +48,20 @@ func NewClusterPediaServerCommand(ctx context.Context) *cobra.Command {
 				return err
 			}
 
+			if _, exist := os.LookupEnv(constants.OtelAgentAddrENV); exist {
+				closeTracer, err := trace.InitTracer(ctx)
+				if err != nil {
+					klog.Fatalf("failed to initialize tracing: %v", err)
+				}
+				defer func() {
+					err := closeTracer(ctx)
+					if err != nil {
+						klog.ErrorS(err, "failed to stop exporter: %v", err)
+						return
+					}
+				}()
+			}
+
 			if err := server.Run(ctx); err != nil {
 				return err
 			}

go.mod

@@ -17,7 +17,11 @@ require (
 	github.com/spf13/cobra v1.7.0
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.8.3
+	go.opentelemetry.io/otel v1.10.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.10.0
+	go.opentelemetry.io/otel/sdk v1.10.0
 	go.uber.org/atomic v1.10.0
+	google.golang.org/grpc v1.54.0
 	gopkg.in/natefinch/lumberjack.v2 v2.2.1
 	gorm.io/datatypes v1.0.7
 	gorm.io/driver/mysql v1.4.4
@@ -124,12 +128,9 @@ require (
 	go.etcd.io/etcd/client/v3 v3.5.9 // indirect
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.35.0 // indirect
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.35.1 // indirect
-	go.opentelemetry.io/otel v1.10.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/internal/retry v1.10.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.10.0 // indirect
-	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.10.0 // indirect
 	go.opentelemetry.io/otel/metric v0.31.0 // indirect
-	go.opentelemetry.io/otel/sdk v1.10.0 // indirect
 	go.opentelemetry.io/otel/trace v1.10.0 // indirect
 	go.opentelemetry.io/proto/otlp v0.19.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
@@ -149,7 +150,6 @@ require (
 	google.golang.org/genproto v0.0.0-20230526161137-0005af68ea54 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20230525234035-dd9d682886f9 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20230525234030-28d5490b6b19 // indirect
-	google.golang.org/grpc v1.54.0 // indirect
 	google.golang.org/protobuf v1.30.0 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect

pkg/constants/constants.go

@@ -0,0 +1,5 @@
+package constants
+
+const (
+	OtelAgentAddrENV = "OTEL_EXPORTER_OTLP_ENDPOINT"
+)

pkg/utils/trace/trace.go

@@ -0,0 +1,38 @@
+package trace
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/sdk/resource"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.7.0"
+	"google.golang.org/grpc"
+	"k8s.io/klog/v2"
+)
+
+// InitTracer initializes the trace provider and the otel grpc exporter.
+func InitTracer(ctx context.Context) (func(ctx context.Context) error, error) {
+	traceExporter, err := otlptracegrpc.New(ctx, otlptracegrpc.WithInsecure(), otlptracegrpc.WithDialOption(grpc.WithBlock()))
+	if err != nil {
+		return nil, err
+	}
+
+	tracerProvider := sdktrace.NewTracerProvider(
+		sdktrace.WithBatcher(traceExporter),
+		sdktrace.WithSampler(sdktrace.AlwaysSample()),
+		sdktrace.WithResource(resource.NewWithAttributes(semconv.SchemaURL)))
+
+	otel.SetTracerProvider(tracerProvider)
+	otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
+
+	return func(ctx context.Context) error {
+		if err := traceExporter.Shutdown(ctx); err != nil {
+			klog.V(2).ErrorS(err, "failed to stop exporter")
+			return err
+		}
+		return nil
+	}, nil
+}