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_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",
+}