[#3] tracing: Move from api-go

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

tracing/examples/grpc/main.go

@@ -0,0 +1,109 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net"
+	"sync"
+	"time"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
+	srv "git.frostfs.info/TrueCloudLab/frostfs-observability/tracing/examples/grpc/server"
+	tracing_grpc "git.frostfs.info/TrueCloudLab/frostfs-observability/tracing/grpc"
+	"go.opentelemetry.io/otel/trace"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+)
+
+type server struct {
+	srv.UnimplementedServerServer
+}
+
+func (s *server) Echo(ctx context.Context, req *srv.Request) (*srv.Response, error) {
+	sc := trace.SpanFromContext(ctx).SpanContext()
+	if !sc.TraceID().IsValid() || !sc.SpanID().IsValid() {
+		return nil, fmt.Errorf("no trace id or span id on server side")
+	}
+	log.Printf("server trace id: %v", sc.TraceID())
+	log.Printf("server span id: %v", sc.SpanID())
+	return &srv.Response{
+		Value: req.GetValue(),
+	}, nil
+}
+
+func verifyClientTraceID(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+	sc := trace.SpanFromContext(ctx).SpanContext()
+	if !sc.TraceID().IsValid() || !sc.SpanID().IsValid() {
+		return fmt.Errorf("no trace id or span id on client side")
+	}
+	log.Printf("client trace id: %v", sc.TraceID())
+	log.Printf("client span id: %v", sc.SpanID())
+	return invoker(ctx, method, req, reply, cc, opts...)
+}
+
+func main() {
+	ctx := context.Background()
+
+	tracingCfg := tracing.Config{
+		Enabled:  true,
+		Exporter: tracing.NoOpExporter,
+		Service:  "example-grpc",
+	}
+	enabled, err := tracing.Setup(ctx, tracingCfg)
+	if err != nil {
+		log.Fatalf("failed to setup tracing: %v", err)
+	}
+	if !enabled {
+		log.Fatalf("failed to enable tracing")
+	}
+
+	lis, err := net.Listen("tcp", ":7000")
+	if err != nil {
+		log.Fatalf("failed to listen: %v", err)
+	}
+	s := grpc.NewServer(
+		grpc.ChainStreamInterceptor(tracing_grpc.NewStreamServerInterceptor()),
+		grpc.ChainUnaryInterceptor(tracing_grpc.NewUnaryServerInterceptor()),
+	)
+	srv.RegisterServerServer(s, &server{})
+
+	wg := &sync.WaitGroup{}
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		if err := s.Serve(lis); err != nil {
+			log.Fatalf("failed to serve: %v", err)
+		}
+	}()
+
+	time.Sleep(1 * time.Second)
+
+	cc, err := grpc.DialContext(ctx,
+		":7000",
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
+		grpc.WithChainUnaryInterceptor(
+			tracing_grpc.NewUnaryClientInteceptor(),
+			verifyClientTraceID,
+		),
+		grpc.WithChainStreamInterceptor(
+			tracing_grpc.NewStreamClientInterceptor(),
+		),
+	)
+	if err != nil {
+		log.Fatalf("failed to dial: %v", err)
+	}
+	client := srv.NewServerClient(cc)
+	resp, err := client.Echo(ctx, &srv.Request{
+		Value: "Hello!",
+	})
+
+	if err != nil {
+		log.Fatalf("failed to get response: %v", err)
+	}
+	log.Printf("response received: %s", resp.GetValue())
+
+	s.GracefulStop()
+
+	wg.Wait()
+}