[#3] tracing: Move from api-go

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

tracing/grpc/interceptors.go

@@ -0,0 +1,160 @@
+package grpc
+
+import (
+	"context"
+	"io"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-observability/tracing"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	semconv "go.opentelemetry.io/otel/semconv/v1.17.0"
+	"go.opentelemetry.io/otel/trace"
+	"google.golang.org/grpc"
+	grpc_codes "google.golang.org/grpc/codes"
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+)
+
+// NewUnaryClientInteceptor creates new gRPC unary interceptor to save gRPC client traces.
+func NewUnaryClientInteceptor() grpc.UnaryClientInterceptor {
+	return func(ctx context.Context, method string, req, reply any, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		ctx, span := startClientSpan(ctx, cc, method)
+		defer span.End()
+
+		err := invoker(ctx, method, req, reply, cc, opts...)
+		if err != nil {
+			grpcStatus, _ := status.FromError(err)
+			span.SetStatus(codes.Error, grpcStatus.Message())
+			span.SetAttributes(semconv.RPCGRPCStatusCodeKey.Int64(int64(grpcStatus.Code())))
+		} else {
+			span.SetStatus(codes.Ok, "")
+			span.SetAttributes(semconv.RPCGRPCStatusCodeKey.Int64(int64(grpc_codes.OK)))
+		}
+
+		return err
+	}
+}
+
+// NewStreamClientInterceptor creates new gRPC stream interceptor to save gRPC client traces.
+func NewStreamClientInterceptor() grpc.StreamClientInterceptor {
+	return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		ctx, span := startClientSpan(ctx, cc, method)
+		str, err := streamer(ctx, desc, cc, method, opts...)
+		if err != nil {
+			grpcStatus, _ := status.FromError(err)
+			span.SetStatus(codes.Error, grpcStatus.Message())
+			span.SetAttributes(semconv.RPCGRPCStatusCodeKey.Int64(int64(grpcStatus.Code())))
+			span.End()
+			return str, err
+		}
+
+		finished := make(chan error)
+		done := make(chan struct{})
+		strWrp := newgRPCClientStream(str, desc, finished, done)
+
+		go func() {
+			defer close(done)
+			defer span.End()
+
+			select {
+			case err := <-finished:
+				if err == nil || err == io.EOF {
+					setGRPCSpanStatus(span, nil)
+				} else {
+					setGRPCSpanStatus(span, err)
+				}
+				return
+			case <-ctx.Done():
+				setGRPCSpanStatus(span, ctx.Err())
+				return
+			}
+		}()
+
+		return strWrp, nil
+	}
+}
+
+// NewUnaryServerInterceptor creates new gRPC unary interceptor to save gRPC server traces.
+func NewUnaryServerInterceptor() grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req any, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
+		ctx = extractGRPCTraceInfo(ctx)
+		var span trace.Span
+		ctx, span = tracing.StartSpanFromContext(ctx, info.FullMethod,
+			trace.WithAttributes(
+				semconv.RPCSystemGRPC,
+				semconv.RPCMethod(info.FullMethod),
+			),
+			trace.WithSpanKind(trace.SpanKindServer))
+		defer span.End()
+
+		resp, err = handler(ctx, req)
+
+		setGRPCSpanStatus(span, err)
+		return
+	}
+}
+
+// NewStreamServerInterceptor creates new gRPC stream interceptor to save gRPC server traces.
+func NewStreamServerInterceptor() grpc.StreamServerInterceptor {
+	return func(srv any, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		ctx := extractGRPCTraceInfo(ss.Context())
+		var span trace.Span
+		ctx, span = tracing.StartSpanFromContext(ctx, info.FullMethod,
+			trace.WithAttributes(
+				semconv.RPCSystemGRPC,
+				semconv.RPCMethod(info.FullMethod),
+			),
+			trace.WithSpanKind(trace.SpanKindServer))
+		defer span.End()
+
+		err := handler(srv, newgRPCServerStream(ctx, ss))
+
+		setGRPCSpanStatus(span, err)
+		return err
+	}
+}
+
+func startClientSpan(ctx context.Context, cc *grpc.ClientConn, method string) (context.Context, trace.Span) {
+	ctx, span := tracing.StartSpanFromContext(ctx, method, trace.WithAttributes(
+		semconv.RPCSystemGRPC,
+		semconv.RPCMethod(method),
+		attribute.String("rpc.grpc.target", cc.Target())),
+		trace.WithSpanKind(trace.SpanKindClient),
+	)
+	ctx = setGRPCTraceInfo(ctx)
+	return ctx, span
+}
+
+func setGRPCSpanStatus(span trace.Span, err error) {
+	if err != nil {
+		grpcStatus, _ := status.FromError(err)
+		span.SetStatus(codes.Error, grpcStatus.Message())
+		span.SetAttributes(semconv.RPCGRPCStatusCodeKey.Int64(int64(grpcStatus.Code())))
+	} else {
+		span.SetStatus(codes.Ok, "")
+		span.SetAttributes(semconv.RPCGRPCStatusCodeKey.Int64(int64(grpc_codes.OK)))
+	}
+}
+
+func extractGRPCTraceInfo(ctx context.Context) context.Context {
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		return ctx
+	}
+	carrier := &grpcMetadataCarrier{
+		md: &md,
+	}
+	return tracing.Propagator.Extract(ctx, carrier)
+}
+
+func setGRPCTraceInfo(ctx context.Context) context.Context {
+	md, ok := metadata.FromOutgoingContext(ctx)
+	if !ok {
+		md = metadata.MD{}
+	}
+	carrier := &grpcMetadataCarrier{
+		md: &md,
+	}
+	tracing.Propagator.Inject(ctx, carrier)
+	return metadata.NewOutgoingContext(ctx, md)
+}