Observatory related fixes (#788)

* fix:observatory not supported by multi-json

* Fix: observatory starts with empty config & fails to close (#957)

* Update strategy_leastping.go (#1019)

* add custom probe URL support for observatory

* add custom probe interval for observer

* apply coding style

* Fix: observatory log & JSON config(#1211)

Co-authored-by: ihotte <ihotte@yeah.net>

* Change default probe url from api.v2fly.org to www.google.com

* Cherry-pick missing code from branch 'dev-advloadblancer-2'

Co-authored-by: Shelikhoo <xiaokangwang@outlook.com>
Co-authored-by: Loyalsoldier <10487845+Loyalsoldier@users.noreply.github.com>
Co-authored-by: fanyiguan <52657276+fanyiguang@users.noreply.github.com>
Co-authored-by: ihotte <3087168217@qq.com>
Co-authored-by: ihotte <ihotte@yeah.net>

app/observatory/command/command.go

@@ -0,0 +1,50 @@
+// +build !confonly
+
+package command
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+
+	core "github.com/xtls/xray-core/core"
+	"github.com/xtls/xray-core/app/observatory"
+	"github.com/xtls/xray-core/common"
+	"github.com/xtls/xray-core/features/extension"
+)
+
+type service struct {
+	UnimplementedObservatoryServiceServer
+	v *core.Instance
+
+	observatory extension.Observatory
+}
+
+func (s *service) GetOutboundStatus(ctx context.Context, request *GetOutboundStatusRequest) (*GetOutboundStatusResponse, error) {
+	resp, err := s.observatory.GetObservation(ctx)
+	if err != nil {
+		return nil, err
+	}
+	retdata := resp.(*observatory.ObservationResult)
+	return &GetOutboundStatusResponse{
+		Status: retdata,
+	}, nil
+}
+
+func (s *service) Register(server *grpc.Server) {
+	RegisterObservatoryServiceServer(server, s)
+}
+
+func init() {
+	common.Must(common.RegisterConfig((*Config)(nil), func(ctx context.Context, cfg interface{}) (interface{}, error) {
+		s := core.MustFromContext(ctx)
+		sv := &service{v: s}
+		err := s.RequireFeatures(func(Observatory extension.Observatory) {
+			sv.observatory = Observatory
+		})
+		if err != nil {
+			return nil, err
+		}
+		return sv, nil
+	}))
+}

app/observatory/command/command.pb.go

@@ -0,0 +1,278 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.27.1
+// 	protoc        v3.18.0
+// source: app/observatory/command/command.proto
+
+package command
+
+import (
+	observatory "github.com/xtls/xray-core/app/observatory"
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
+	reflect "reflect"
+	sync "sync"
+)
+
+const (
+	// Verify that this generated code is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
+	// Verify that runtime/protoimpl is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
+)
+
+type GetOutboundStatusRequest struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+}
+
+func (x *GetOutboundStatusRequest) Reset() {
+	*x = GetOutboundStatusRequest{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_app_observatory_command_command_proto_msgTypes[0]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *GetOutboundStatusRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*GetOutboundStatusRequest) ProtoMessage() {}
+
+func (x *GetOutboundStatusRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_app_observatory_command_command_proto_msgTypes[0]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use GetOutboundStatusRequest.ProtoReflect.Descriptor instead.
+func (*GetOutboundStatusRequest) Descriptor() ([]byte, []int) {
+	return file_app_observatory_command_command_proto_rawDescGZIP(), []int{0}
+}
+
+type GetOutboundStatusResponse struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	Status *observatory.ObservationResult `protobuf:"bytes,1,opt,name=status,proto3" json:"status,omitempty"`
+}
+
+func (x *GetOutboundStatusResponse) Reset() {
+	*x = GetOutboundStatusResponse{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_app_observatory_command_command_proto_msgTypes[1]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *GetOutboundStatusResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*GetOutboundStatusResponse) ProtoMessage() {}
+
+func (x *GetOutboundStatusResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_app_observatory_command_command_proto_msgTypes[1]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use GetOutboundStatusResponse.ProtoReflect.Descriptor instead.
+func (*GetOutboundStatusResponse) Descriptor() ([]byte, []int) {
+	return file_app_observatory_command_command_proto_rawDescGZIP(), []int{1}
+}
+
+func (x *GetOutboundStatusResponse) GetStatus() *observatory.ObservationResult {
+	if x != nil {
+		return x.Status
+	}
+	return nil
+}
+
+type Config struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+}
+
+func (x *Config) Reset() {
+	*x = Config{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_app_observatory_command_command_proto_msgTypes[2]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *Config) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*Config) ProtoMessage() {}
+
+func (x *Config) ProtoReflect() protoreflect.Message {
+	mi := &file_app_observatory_command_command_proto_msgTypes[2]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use Config.ProtoReflect.Descriptor instead.
+func (*Config) Descriptor() ([]byte, []int) {
+	return file_app_observatory_command_command_proto_rawDescGZIP(), []int{2}
+}
+
+var File_app_observatory_command_command_proto protoreflect.FileDescriptor
+
+var file_app_observatory_command_command_proto_rawDesc = []byte{
+	0x0a, 0x25, 0x61, 0x70, 0x70, 0x2f, 0x6f, 0x62, 0x73, 0x65, 0x72, 0x76, 0x61, 0x74, 0x6f, 0x72,
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+	0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
+}
+
+var (
+	file_app_observatory_command_command_proto_rawDescOnce sync.Once
+	file_app_observatory_command_command_proto_rawDescData = file_app_observatory_command_command_proto_rawDesc
+)
+
+func file_app_observatory_command_command_proto_rawDescGZIP() []byte {
+	file_app_observatory_command_command_proto_rawDescOnce.Do(func() {
+		file_app_observatory_command_command_proto_rawDescData = protoimpl.X.CompressGZIP(file_app_observatory_command_command_proto_rawDescData)
+	})
+	return file_app_observatory_command_command_proto_rawDescData
+}
+
+var file_app_observatory_command_command_proto_msgTypes = make([]protoimpl.MessageInfo, 3)
+var file_app_observatory_command_command_proto_goTypes = []interface{}{
+	(*GetOutboundStatusRequest)(nil),      // 0: xray.core.app.observatory.command.GetOutboundStatusRequest
+	(*GetOutboundStatusResponse)(nil),     // 1: xray.core.app.observatory.command.GetOutboundStatusResponse
+	(*Config)(nil),                        // 2: xray.core.app.observatory.command.Config
+	(*observatory.ObservationResult)(nil), // 3: xray.core.app.observatory.ObservationResult
+}
+var file_app_observatory_command_command_proto_depIdxs = []int32{
+	3, // 0: xray.core.app.observatory.command.GetOutboundStatusResponse.status:type_name -> xray.core.app.observatory.ObservationResult
+	0, // 1: xray.core.app.observatory.command.ObservatoryService.GetOutboundStatus:input_type -> xray.core.app.observatory.command.GetOutboundStatusRequest
+	1, // 2: xray.core.app.observatory.command.ObservatoryService.GetOutboundStatus:output_type -> xray.core.app.observatory.command.GetOutboundStatusResponse
+	2, // [2:3] is the sub-list for method output_type
+	1, // [1:2] is the sub-list for method input_type
+	1, // [1:1] is the sub-list for extension type_name
+	1, // [1:1] is the sub-list for extension extendee
+	0, // [0:1] is the sub-list for field type_name
+}
+
+func init() { file_app_observatory_command_command_proto_init() }
+func file_app_observatory_command_command_proto_init() {
+	if File_app_observatory_command_command_proto != nil {
+		return
+	}
+	if !protoimpl.UnsafeEnabled {
+		file_app_observatory_command_command_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*GetOutboundStatusRequest); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_app_observatory_command_command_proto_msgTypes[1].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*GetOutboundStatusResponse); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_app_observatory_command_command_proto_msgTypes[2].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*Config); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+	}
+	type x struct{}
+	out := protoimpl.TypeBuilder{
+		File: protoimpl.DescBuilder{
+			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
+			RawDescriptor: file_app_observatory_command_command_proto_rawDesc,
+			NumEnums:      0,
+			NumMessages:   3,
+			NumExtensions: 0,
+			NumServices:   1,
+		},
+		GoTypes:           file_app_observatory_command_command_proto_goTypes,
+		DependencyIndexes: file_app_observatory_command_command_proto_depIdxs,
+		MessageInfos:      file_app_observatory_command_command_proto_msgTypes,
+	}.Build()
+	File_app_observatory_command_command_proto = out.File
+	file_app_observatory_command_command_proto_rawDesc = nil
+	file_app_observatory_command_command_proto_goTypes = nil
+	file_app_observatory_command_command_proto_depIdxs = nil
+}

app/observatory/command/command.proto

@@ -0,0 +1,24 @@
+syntax = "proto3";
+
+package xray.core.app.observatory.command;
+option csharp_namespace = "Xray.Core.App.Observatory.Command";
+option go_package = "github.com/xtls/xray-core/app/observatory/command";
+option java_package = "com.xray.core.app.observatory.command";
+option java_multiple_files = true;
+
+import "app/observatory/config.proto";
+
+message GetOutboundStatusRequest {
+}
+
+message GetOutboundStatusResponse {
+  xray.core.app.observatory.ObservationResult status = 1;
+}
+
+service ObservatoryService {
+  rpc GetOutboundStatus(GetOutboundStatusRequest)
+      returns (GetOutboundStatusResponse) {}
+}
+
+
+message Config {}

app/observatory/command/command_grpc.pb.go

@@ -0,0 +1,101 @@
+// Code generated by protoc-gen-go-grpc. DO NOT EDIT.
+
+package command
+
+import (
+	context "context"
+	grpc "google.golang.org/grpc"
+	codes "google.golang.org/grpc/codes"
+	status "google.golang.org/grpc/status"
+)
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the grpc package it is being compiled against.
+// Requires gRPC-Go v1.32.0 or later.
+const _ = grpc.SupportPackageIsVersion7
+
+// ObservatoryServiceClient is the client API for ObservatoryService service.
+//
+// For semantics around ctx use and closing/ending streaming RPCs, please refer to https://pkg.go.dev/google.golang.org/grpc/?tab=doc#ClientConn.NewStream.
+type ObservatoryServiceClient interface {
+	GetOutboundStatus(ctx context.Context, in *GetOutboundStatusRequest, opts ...grpc.CallOption) (*GetOutboundStatusResponse, error)
+}
+
+type observatoryServiceClient struct {
+	cc grpc.ClientConnInterface
+}
+
+func NewObservatoryServiceClient(cc grpc.ClientConnInterface) ObservatoryServiceClient {
+	return &observatoryServiceClient{cc}
+}
+
+func (c *observatoryServiceClient) GetOutboundStatus(ctx context.Context, in *GetOutboundStatusRequest, opts ...grpc.CallOption) (*GetOutboundStatusResponse, error) {
+	out := new(GetOutboundStatusResponse)
+	err := c.cc.Invoke(ctx, "/xray.core.app.observatory.command.ObservatoryService/GetOutboundStatus", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// ObservatoryServiceServer is the server API for ObservatoryService service.
+// All implementations must embed UnimplementedObservatoryServiceServer
+// for forward compatibility
+type ObservatoryServiceServer interface {
+	GetOutboundStatus(context.Context, *GetOutboundStatusRequest) (*GetOutboundStatusResponse, error)
+	mustEmbedUnimplementedObservatoryServiceServer()
+}
+
+// UnimplementedObservatoryServiceServer must be embedded to have forward compatible implementations.
+type UnimplementedObservatoryServiceServer struct {
+}
+
+func (UnimplementedObservatoryServiceServer) GetOutboundStatus(context.Context, *GetOutboundStatusRequest) (*GetOutboundStatusResponse, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method GetOutboundStatus not implemented")
+}
+func (UnimplementedObservatoryServiceServer) mustEmbedUnimplementedObservatoryServiceServer() {}
+
+// UnsafeObservatoryServiceServer may be embedded to opt out of forward compatibility for this service.
+// Use of this interface is not recommended, as added methods to ObservatoryServiceServer will
+// result in compilation errors.
+type UnsafeObservatoryServiceServer interface {
+	mustEmbedUnimplementedObservatoryServiceServer()
+}
+
+func RegisterObservatoryServiceServer(s grpc.ServiceRegistrar, srv ObservatoryServiceServer) {
+	s.RegisterService(&ObservatoryService_ServiceDesc, srv)
+}
+
+func _ObservatoryService_GetOutboundStatus_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(GetOutboundStatusRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(ObservatoryServiceServer).GetOutboundStatus(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/xray.core.app.observatory.command.ObservatoryService/GetOutboundStatus",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(ObservatoryServiceServer).GetOutboundStatus(ctx, req.(*GetOutboundStatusRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
+// ObservatoryService_ServiceDesc is the grpc.ServiceDesc for ObservatoryService service.
+// It's only intended for direct use with grpc.RegisterService,
+// and not to be introspected or modified (even as a copy)
+var ObservatoryService_ServiceDesc = grpc.ServiceDesc{
+	ServiceName: "xray.core.app.observatory.command.ObservatoryService",
+	HandlerType: (*ObservatoryServiceServer)(nil),
+	Methods: []grpc.MethodDesc{
+		{
+			MethodName: "GetOutboundStatus",
+			Handler:    _ObservatoryService_GetOutboundStatus_Handler,
+		},
+	},
+	Streams:  []grpc.StreamDesc{},
+	Metadata: "app/observatory/command/command.proto",
+}

app/observatory/observer.go

@@ -102,7 +102,7 @@ func (o *Observer) probe(outbound string) ProbeResult {
 		DialContext: func(ctx context.Context, network string, addr string) (net.Conn, error) {
 			var connection net.Conn
 			taskErr := task.Run(ctx, func() error {
-				// MUST use V2Fly's built in context system
+				// MUST use Xray's built in context system
 				dest, err := v2net.ParseDestination(network + ":" + addr)
 				if err != nil {
 					return newError("cannot understand address").Base(err)
@@ -133,7 +133,7 @@ func (o *Observer) probe(outbound string) ProbeResult {
 	var GETTime time.Duration
 	err := task.Run(o.ctx, func() error {
 		startTime := time.Now()
-		probeURL := "https://api.v2fly.org/checkConnection.svgz"
+		probeURL := "https://www.google.com/generate_204"
 		if o.config.ProbeUrl != "" {
 			probeURL = o.config.ProbeUrl
 		}

app/proxyman/outbound/handler.go

@@ -136,13 +136,17 @@ func (h *Handler) Tag() string {
 func (h *Handler) Dispatch(ctx context.Context, link *transport.Link) {
 	if h.mux != nil && (h.mux.Enabled || session.MuxPreferedFromContext(ctx)) {
 		if err := h.mux.Dispatch(ctx, link); err != nil {
-			newError("failed to process mux outbound traffic").Base(err).WriteToLog(session.ExportIDToError(ctx))
+			err := newError("failed to process mux outbound traffic").Base(err)
+			session.SubmitOutboundErrorToOriginator(ctx, err)
+			err.WriteToLog(session.ExportIDToError(ctx))
 			common.Interrupt(link.Writer)
 		}
 	} else {
 		if err := h.proxy.Process(ctx, link, h); err != nil {
 			// Ensure outbound ray is properly closed.
-			newError("failed to process outbound traffic").Base(err).WriteToLog(session.ExportIDToError(ctx))
+			err := newError("failed to process outbound traffic").Base(err)
+			session.SubmitOutboundErrorToOriginator(ctx, err)
+			err.WriteToLog(session.ExportIDToError(ctx))
 			common.Interrupt(link.Writer)
 		} else {
 			common.Must(common.Close(link.Writer))

app/router/command/command_test.go

@@ -284,7 +284,7 @@ func TestSerivceTestRoute(t *testing.T) {
 	r := new(router.Router)
 	mockCtl := gomock.NewController(t)
 	defer mockCtl.Finish()
-	common.Must(r.Init(&router.Config{
+	common.Must(r.Init(context.TODO(), &router.Config{
 		Rule: []*router.RoutingRule{
 			{
 				InboundTag: []string{"in"},

app/router/config.go

@@ -158,9 +158,21 @@ func (rr *RoutingRule) BuildCondition() (Condition, error) {
 }
 
 func (br *BalancingRule) Build(ohm outbound.Manager) (*Balancer, error) {
+	switch br.Strategy {
+	case "leastPing":
+		return &Balancer{
+			selectors: br.OutboundSelector,
+			strategy:  &LeastPingStrategy{},
+			ohm:       ohm,
+		}, nil
+	case "random":
+		fallthrough
+	default:
 		return &Balancer{
 			selectors: br.OutboundSelector,
 			strategy:  &RandomStrategy{},
 			ohm:       ohm,
 		}, nil
+
+	}
 }

app/router/router.go

@@ -29,7 +29,7 @@ type Route struct {
 }
 
 // Init initializes the Router.
-func (r *Router) Init(config *Config, d dns.Client, ohm outbound.Manager) error {
+func (r *Router) Init(ctx context.Context, config *Config, d dns.Client, ohm outbound.Manager) error {
 	r.domainStrategy = config.DomainStrategy
 	r.dns = d
 
@@ -39,6 +39,7 @@ func (r *Router) Init(config *Config, d dns.Client, ohm outbound.Manager) error
 		if err != nil {
 			return err
 		}
+		balancer.InjectContext(ctx)
 		r.balancers[rule.Tag] = balancer
 	}
 
@@ -140,7 +141,7 @@ func init() {
 	common.Must(common.RegisterConfig((*Config)(nil), func(ctx context.Context, config interface{}) (interface{}, error) {
 		r := new(Router)
 		if err := core.RequireFeatures(ctx, func(d dns.Client, ohm outbound.Manager) error {
-			return r.Init(config.(*Config), d, ohm)
+			return r.Init(ctx, config.(*Config), d, ohm)
 		}); err != nil {
 			return nil, err
 		}

app/router/router_test.go

@@ -42,7 +42,7 @@ func TestSimpleRouter(t *testing.T) {
 	mockHs := mocks.NewOutboundHandlerSelector(mockCtl)
 
 	r := new(Router)
-	common.Must(r.Init(config, mockDNS, &mockOutboundManager{
+	common.Must(r.Init(context.TODO(), config, mockDNS, &mockOutboundManager{
 		Manager:         mockOhm,
 		HandlerSelector: mockHs,
 	}))
@@ -83,7 +83,7 @@ func TestSimpleBalancer(t *testing.T) {
 	mockHs.EXPECT().Select(gomock.Eq([]string{"test-"})).Return([]string{"test"})
 
 	r := new(Router)
-	common.Must(r.Init(config, mockDNS, &mockOutboundManager{
+	common.Must(r.Init(context.TODO(), config, mockDNS, &mockOutboundManager{
 		Manager:         mockOhm,
 		HandlerSelector: mockHs,
 	}))
@@ -125,7 +125,7 @@ func TestIPOnDemand(t *testing.T) {
 	}).Return([]net.IP{{192, 168, 0, 1}}, nil).AnyTimes()
 
 	r := new(Router)
-	common.Must(r.Init(config, mockDNS, nil))
+	common.Must(r.Init(context.TODO(), config, mockDNS, nil))
 
 	ctx := session.ContextWithOutbound(context.Background(), &session.Outbound{Target: net.TCPDestination(net.DomainAddress("example.com"), 80)})
 	route, err := r.PickRoute(routing_session.AsRoutingContext(ctx))
@@ -164,7 +164,7 @@ func TestIPIfNonMatchDomain(t *testing.T) {
 	}).Return([]net.IP{{192, 168, 0, 1}}, nil).AnyTimes()
 
 	r := new(Router)
-	common.Must(r.Init(config, mockDNS, nil))
+	common.Must(r.Init(context.TODO(), config, mockDNS, nil))
 
 	ctx := session.ContextWithOutbound(context.Background(), &session.Outbound{Target: net.TCPDestination(net.DomainAddress("example.com"), 80)})
 	route, err := r.PickRoute(routing_session.AsRoutingContext(ctx))
@@ -198,7 +198,7 @@ func TestIPIfNonMatchIP(t *testing.T) {
 	mockDNS := mocks.NewDNSClient(mockCtl)
 
 	r := new(Router)
-	common.Must(r.Init(config, mockDNS, nil))
+	common.Must(r.Init(context.TODO(), config, mockDNS, nil))
 
 	ctx := session.ContextWithOutbound(context.Background(), &session.Outbound{Target: net.TCPDestination(net.LocalHostIP, 80)})
 	route, err := r.PickRoute(routing_session.AsRoutingContext(ctx))

app/router/strategy_leastping.go

@@ -36,6 +36,7 @@ func (l *LeastPingStrategy) PickOutbound(strings []string) string {
 		for _, v := range status {
 			if outboundsList.contains(v.OutboundTag) && v.Alive && v.Delay < leastPing {
 				selectedOutboundName = v.OutboundTag
+				leastPing = v.Delay
 			}
 		}
 		return selectedOutboundName

infra/conf/api.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/xtls/xray-core/app/commander"
 	loggerservice "github.com/xtls/xray-core/app/log/command"
+	observatoryservice "github.com/xtls/xray-core/app/observatory/command"
 	handlerservice "github.com/xtls/xray-core/app/proxyman/command"
 	statsservice "github.com/xtls/xray-core/app/stats/command"
 	"github.com/xtls/xray-core/common/serial"
@@ -31,6 +32,8 @@ func (c *APIConfig) Build() (*commander.Config, error) {
 			services = append(services, serial.ToTypedMessage(&loggerservice.Config{}))
 		case "statsservice":
 			services = append(services, serial.ToTypedMessage(&statsservice.Config{}))
+		case "observatoryservice":
+			services = append(services, serial.ToTypedMessage(&observatoryservice.Config{}))
 		}
 	}
 

infra/conf/cfgcommon/duration/duration.go

@@ -0,0 +1,33 @@
+package duration
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+)
+
+type Duration int64
+
+func (d *Duration) MarshalJSON() ([]byte, error) {
+	dr := time.Duration(*d)
+	return json.Marshal(dr.String())
+}
+
+func (d *Duration) UnmarshalJSON(b []byte) error {
+	var v interface{}
+	if err := json.Unmarshal(b, &v); err != nil {
+		return err
+	}
+	switch value := v.(type) {
+	case string:
+		var err error
+		dr, err := time.ParseDuration(value)
+		if err != nil {
+			return err
+		}
+		*d = Duration(dr)
+		return nil
+	default:
+		return fmt.Errorf("invalid duration: %v", v)
+	}
+}

infra/conf/cfgcommon/duration/duration_test.go

@@ -0,0 +1,33 @@
+package duration_test
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/xtls/xray-core/infra/conf/cfgcommon/duration"
+)
+
+type testWithDuration struct {
+	Duration duration.Duration
+}
+
+func TestDurationJSON(t *testing.T) {
+	expected := &testWithDuration{
+		Duration: duration.Duration(time.Hour),
+	}
+	data, err := json.Marshal(expected)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	actual := &testWithDuration{}
+	err = json.Unmarshal(data, &actual)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	if actual.Duration != expected.Duration {
+		t.Errorf("expected: %s, actual: %s", time.Duration(expected.Duration), time.Duration(actual.Duration))
+	}
+}

infra/conf/observatory.go

@@ -2,13 +2,17 @@ package conf
 
 import (
 	"github.com/golang/protobuf/proto"
+	
 	"github.com/xtls/xray-core/app/observatory"
+	"github.com/xtls/xray-core/infra/conf/cfgcommon/duration"
 )
 
 type ObservatoryConfig struct {
 	SubjectSelector []string          `json:"subjectSelector"`
+	ProbeURL        string            `json:"probeURL"`
+	ProbeInterval   duration.Duration `json:"probeInterval"`
 }
 
-func (o ObservatoryConfig) Build() (proto.Message, error) {
-	return &observatory.Config{SubjectSelector: o.SubjectSelector}, nil
+func (o *ObservatoryConfig) Build() (proto.Message, error) {
+	return &observatory.Config{SubjectSelector: o.SubjectSelector, ProbeUrl: o.ProbeURL, ProbeInterval: int64(o.ProbeInterval)}, nil
 }

infra/conf/router.go

@@ -18,9 +18,16 @@ type RouterRulesConfig struct {
 	DomainStrategy string            `json:"domainStrategy"`
 }
 
+// StrategyConfig represents a strategy config
+type StrategyConfig struct {
+	Type     string           `json:"type"`
+	Settings *json.RawMessage `json:"settings"`
+}
+
 type BalancingRule struct {
 	Tag       string         `json:"tag"`
 	Selectors StringList     `json:"selector"`
+	Strategy  StrategyConfig `json:"strategy"`
 }
 
 func (r *BalancingRule) Build() (*router.BalancingRule, error) {
@@ -31,9 +38,20 @@ func (r *BalancingRule) Build() (*router.BalancingRule, error) {
 		return nil, newError("empty selector list")
 	}
 
+	var strategy string
+	switch strings.ToLower(r.Strategy.Type) {
+	case strategyRandom, "":
+		strategy = strategyRandom
+	case strategyLeastPing:
+		strategy = "leastPing"
+	default:
+		return nil, newError("unknown balancing strategy: " + r.Strategy.Type)
+	}
+
 	return &router.BalancingRule{
 		Tag:              r.Tag,
 		OutboundSelector: []string(r.Selectors),
+		Strategy:         strategy,
 	}, nil
 }
 

infra/conf/router_strategy.go

@@ -0,0 +1,6 @@
+package conf
+
+const (
+	strategyRandom    string = "random"
+	strategyLeastPing string = "leastping"
+)

infra/conf/router_test.go

@@ -107,6 +107,7 @@ func TestRouterConfig(t *testing.T) {
 					{
 						Tag:              "b1",
 						OutboundSelector: []string{"test"},
+						Strategy:         "random",
 					},
 				},
 				Rule: []*router.RoutingRule{

infra/conf/xray.go

@@ -464,6 +464,10 @@ func (c *Config) Override(o *Config, fn string) {
 		c.FakeDNS = o.FakeDNS
 	}
 
+	if o.Observatory != nil {
+		c.Observatory = o.Observatory
+	}
+
 	// deprecated attrs... keep them for now
 	if o.InboundConfig != nil {
 		c.InboundConfig = o.InboundConfig

main/distro/all/all.go

@@ -14,6 +14,9 @@ import (
 	_ "github.com/xtls/xray-core/app/proxyman/command"
 	_ "github.com/xtls/xray-core/app/stats/command"
 
+	// Developer preview services
+	_ "github.com/xtls/xray-core/app/observatory/command"
+
 	// Other optional features.
 	_ "github.com/xtls/xray-core/app/dns"
 	_ "github.com/xtls/xray-core/app/dns/fakedns"
@@ -26,6 +29,9 @@ import (
 	// Fix dependency cycle caused by core import in internet package
 	_ "github.com/xtls/xray-core/transport/internet/tagged/taggedimpl"
 
+	// Developer preview features
+	_ "github.com/xtls/xray-core/app/observatory"
+
 	// Inbound and outbound proxies.
 	_ "github.com/xtls/xray-core/proxy/blackhole"
 	_ "github.com/xtls/xray-core/proxy/dns"