lnrpc: add GetState to stateservice (v1/state)

This commit adds a new GetState call to the state service in order to
make leader election integrate simply with k8s using a readinessProbe.

lnrpc/rest-annotations.yaml

@@ -261,6 +261,8 @@ http:
     # stateservice.proto
     - selector: lnrpc.State.SubscribeState
       get: "/v1/state/subscribe"
+    - selector: lnrpc.State.GetState
+      get: "/v1/state"
 
     # verrpc/verrpc.proto
     - selector: verrpc.Versioner.GetVersion

lnrpc/stateservice.pb.go

@@ -169,6 +169,91 @@ func (x *SubscribeStateResponse) GetState() WalletState {
 	return WalletState_NON_EXISTING
 }
 
+type GetStateRequest struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+}
+
+func (x *GetStateRequest) Reset() {
+	*x = GetStateRequest{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_stateservice_proto_msgTypes[2]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *GetStateRequest) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*GetStateRequest) ProtoMessage() {}
+
+func (x *GetStateRequest) ProtoReflect() protoreflect.Message {
+	mi := &file_stateservice_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 GetStateRequest.ProtoReflect.Descriptor instead.
+func (*GetStateRequest) Descriptor() ([]byte, []int) {
+	return file_stateservice_proto_rawDescGZIP(), []int{2}
+}
+
+type GetStateResponse struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	State WalletState `protobuf:"varint,1,opt,name=State,proto3,enum=lnrpc.WalletState" json:"State,omitempty"`
+}
+
+func (x *GetStateResponse) Reset() {
+	*x = GetStateResponse{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_stateservice_proto_msgTypes[3]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *GetStateResponse) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*GetStateResponse) ProtoMessage() {}
+
+func (x *GetStateResponse) ProtoReflect() protoreflect.Message {
+	mi := &file_stateservice_proto_msgTypes[3]
+	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 GetStateResponse.ProtoReflect.Descriptor instead.
+func (*GetStateResponse) Descriptor() ([]byte, []int) {
+	return file_stateservice_proto_rawDescGZIP(), []int{3}
+}
+
+func (x *GetStateResponse) GetState() WalletState {
+	if x != nil {
+		return x.State
+	}
+	return WalletState_NON_EXISTING
+}
+
 var File_stateservice_proto protoreflect.FileDescriptor
 
 var file_stateservice_proto_rawDesc = []byte{
@@ -179,22 +264,31 @@ var file_stateservice_proto_rawDesc = []byte{
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+	0x6f, 0x74, 0x6f, 0x33,
 }
 
 var (
@@ -210,21 +304,26 @@ func file_stateservice_proto_rawDescGZIP() []byte {
 }
 
 var file_stateservice_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
-var file_stateservice_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
+var file_stateservice_proto_msgTypes = make([]protoimpl.MessageInfo, 4)
 var file_stateservice_proto_goTypes = []interface{}{
 	(WalletState)(0),               // 0: lnrpc.WalletState
 	(*SubscribeStateRequest)(nil),  // 1: lnrpc.SubscribeStateRequest
 	(*SubscribeStateResponse)(nil), // 2: lnrpc.SubscribeStateResponse
+	(*GetStateRequest)(nil),        // 3: lnrpc.GetStateRequest
+	(*GetStateResponse)(nil),       // 4: lnrpc.GetStateResponse
 }
 var file_stateservice_proto_depIdxs = []int32{
 	0, // 0: lnrpc.SubscribeStateResponse.state:type_name -> lnrpc.WalletState
-	1, // 1: lnrpc.State.SubscribeState:input_type -> lnrpc.SubscribeStateRequest
-	2, // 2: lnrpc.State.SubscribeState:output_type -> lnrpc.SubscribeStateResponse
-	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
+	0, // 1: lnrpc.GetStateResponse.State:type_name -> lnrpc.WalletState
+	1, // 2: lnrpc.State.SubscribeState:input_type -> lnrpc.SubscribeStateRequest
+	3, // 3: lnrpc.State.GetState:input_type -> lnrpc.GetStateRequest
+	2, // 4: lnrpc.State.SubscribeState:output_type -> lnrpc.SubscribeStateResponse
+	4, // 5: lnrpc.State.GetState:output_type -> lnrpc.GetStateResponse
+	4, // [4:6] is the sub-list for method output_type
+	2, // [2:4] is the sub-list for method input_type
+	2, // [2:2] is the sub-list for extension type_name
+	2, // [2:2] is the sub-list for extension extendee
+	0, // [0:2] is the sub-list for field type_name
 }
 
 func init() { file_stateservice_proto_init() }
@@ -257,6 +356,30 @@ func file_stateservice_proto_init() {
 				return nil
 			}
 		}
+		file_stateservice_proto_msgTypes[2].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*GetStateRequest); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_stateservice_proto_msgTypes[3].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*GetStateResponse); 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{
@@ -264,7 +387,7 @@ func file_stateservice_proto_init() {
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: file_stateservice_proto_rawDesc,
 			NumEnums:      1,
-			NumMessages:   2,
+			NumMessages:   4,
 			NumExtensions: 0,
 			NumServices:   1,
 		},
@@ -294,6 +417,9 @@ type StateClient interface {
 	// SubscribeState subscribes to the state of the wallet. The current wallet
 	// state will always be delivered immediately.
 	SubscribeState(ctx context.Context, in *SubscribeStateRequest, opts ...grpc.CallOption) (State_SubscribeStateClient, error)
+	// GetState returns the current wallet state without streaming further
+	// changes.
+	GetState(ctx context.Context, in *GetStateRequest, opts ...grpc.CallOption) (*GetStateResponse, error)
 }
 
 type stateClient struct {
@@ -336,11 +462,23 @@ func (x *stateSubscribeStateClient) Recv() (*SubscribeStateResponse, error) {
 	return m, nil
 }
 
+func (c *stateClient) GetState(ctx context.Context, in *GetStateRequest, opts ...grpc.CallOption) (*GetStateResponse, error) {
+	out := new(GetStateResponse)
+	err := c.cc.Invoke(ctx, "/lnrpc.State/GetState", in, out, opts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 // StateServer is the server API for State service.
 type StateServer interface {
 	// SubscribeState subscribes to the state of the wallet. The current wallet
 	// state will always be delivered immediately.
 	SubscribeState(*SubscribeStateRequest, State_SubscribeStateServer) error
+	// GetState returns the current wallet state without streaming further
+	// changes.
+	GetState(context.Context, *GetStateRequest) (*GetStateResponse, error)
 }
 
 // UnimplementedStateServer can be embedded to have forward compatible implementations.
@@ -350,6 +488,9 @@ type UnimplementedStateServer struct {
 func (*UnimplementedStateServer) SubscribeState(*SubscribeStateRequest, State_SubscribeStateServer) error {
 	return status.Errorf(codes.Unimplemented, "method SubscribeState not implemented")
 }
+func (*UnimplementedStateServer) GetState(context.Context, *GetStateRequest) (*GetStateResponse, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method GetState not implemented")
+}
 
 func RegisterStateServer(s *grpc.Server, srv StateServer) {
 	s.RegisterService(&_State_serviceDesc, srv)
@@ -376,10 +517,33 @@ func (x *stateSubscribeStateServer) Send(m *SubscribeStateResponse) error {
 	return x.ServerStream.SendMsg(m)
 }
 
+func _State_GetState_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(GetStateRequest)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(StateServer).GetState(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: "/lnrpc.State/GetState",
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(StateServer).GetState(ctx, req.(*GetStateRequest))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 var _State_serviceDesc = grpc.ServiceDesc{
 	ServiceName: "lnrpc.State",
 	HandlerType: (*StateServer)(nil),
-	Methods:     []grpc.MethodDesc{},
+	Methods: []grpc.MethodDesc{
+		{
+			MethodName: "GetState",
+			Handler:    _State_GetState_Handler,
+		},
+	},
 	Streams: []grpc.StreamDesc{
 		{
 			StreamName:    "SubscribeState",

lnrpc/stateservice.pb.gw.go

@@ -48,6 +48,24 @@ func request_State_SubscribeState_0(ctx context.Context, marshaler runtime.Marsh
 
 }
 
+func request_State_GetState_0(ctx context.Context, marshaler runtime.Marshaler, client StateClient, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq GetStateRequest
+	var metadata runtime.ServerMetadata
+
+	msg, err := client.GetState(ctx, &protoReq, grpc.Header(&metadata.HeaderMD), grpc.Trailer(&metadata.TrailerMD))
+	return msg, metadata, err
+
+}
+
+func local_request_State_GetState_0(ctx context.Context, marshaler runtime.Marshaler, server StateServer, req *http.Request, pathParams map[string]string) (proto.Message, runtime.ServerMetadata, error) {
+	var protoReq GetStateRequest
+	var metadata runtime.ServerMetadata
+
+	msg, err := server.GetState(ctx, &protoReq)
+	return msg, metadata, err
+
+}
+
 // RegisterStateHandlerServer registers the http handlers for service State to "mux".
 // UnaryRPC     :call StateServer directly.
 // StreamingRPC :currently unsupported pending https://github.com/grpc/grpc-go/issues/906.
@@ -60,6 +78,26 @@ func RegisterStateHandlerServer(ctx context.Context, mux *runtime.ServeMux, serv
 		return
 	})
 
+	mux.Handle("GET", pattern_State_GetState_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateIncomingContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := local_request_State_GetState_0(rctx, inboundMarshaler, server, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_State_GetState_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
 	return nil
 }
 
@@ -121,13 +159,37 @@ func RegisterStateHandlerClient(ctx context.Context, mux *runtime.ServeMux, clie
 
 	})
 
+	mux.Handle("GET", pattern_State_GetState_0, func(w http.ResponseWriter, req *http.Request, pathParams map[string]string) {
+		ctx, cancel := context.WithCancel(req.Context())
+		defer cancel()
+		inboundMarshaler, outboundMarshaler := runtime.MarshalerForRequest(mux, req)
+		rctx, err := runtime.AnnotateContext(ctx, mux, req)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+		resp, md, err := request_State_GetState_0(rctx, inboundMarshaler, client, req, pathParams)
+		ctx = runtime.NewServerMetadataContext(ctx, md)
+		if err != nil {
+			runtime.HTTPError(ctx, mux, outboundMarshaler, w, req, err)
+			return
+		}
+
+		forward_State_GetState_0(ctx, mux, outboundMarshaler, w, req, resp, mux.GetForwardResponseOptions()...)
+
+	})
+
 	return nil
 }
 
 var (
 	pattern_State_SubscribeState_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1, 2, 2}, []string{"v1", "state", "subscribe"}, "", runtime.AssumeColonVerbOpt(true)))
+
+	pattern_State_GetState_0 = runtime.MustPattern(runtime.NewPattern(1, []int{2, 0, 2, 1}, []string{"v1", "state"}, "", runtime.AssumeColonVerbOpt(true)))
 )
 
 var (
 	forward_State_SubscribeState_0 = runtime.ForwardResponseStream
+
+	forward_State_GetState_0 = runtime.ForwardResponseMessage
 )

lnrpc/stateservice.proto

@@ -29,6 +29,10 @@ service State {
     // state will always be delivered immediately.
     rpc SubscribeState (SubscribeStateRequest)
         returns (stream SubscribeStateResponse);
+
+    // GetState returns the current wallet state without streaming further
+    // changes.
+    rpc GetState (GetStateRequest) returns (GetStateResponse);
 }
 
 enum WalletState {
@@ -46,3 +50,10 @@ message SubscribeStateRequest {
 message SubscribeStateResponse {
     WalletState state = 1;
 }
+
+message GetStateRequest {
+}
+
+message GetStateResponse {
+    WalletState State = 1;
+}

lnrpc/stateservice.swagger.json

@@ -11,6 +11,29 @@
     "application/json"
   ],
   "paths": {
+    "/v1/state": {
+      "get": {
+        "summary": "GetState returns the current wallet state without streaming further\nchanges.",
+        "operationId": "GetState",
+        "responses": {
+          "200": {
+            "description": "A successful response.",
+            "schema": {
+              "$ref": "#/definitions/lnrpcGetStateResponse"
+            }
+          },
+          "default": {
+            "description": "An unexpected error response",
+            "schema": {
+              "$ref": "#/definitions/runtimeError"
+            }
+          }
+        },
+        "tags": [
+          "State"
+        ]
+      }
+    },
     "/v1/state/subscribe": {
       "get": {
         "summary": "SubscribeState subscribes to the state of the wallet. The current wallet\nstate will always be delivered immediately.",
@@ -45,6 +68,14 @@
     }
   },
   "definitions": {
+    "lnrpcGetStateResponse": {
+      "type": "object",
+      "properties": {
+        "State": {
+          "$ref": "#/definitions/lnrpcWalletState"
+        }
+      }
+    },
     "lnrpcSubscribeStateResponse": {
       "type": "object",
       "properties": {

rpcperms/interceptor.go

@@ -82,6 +82,7 @@ var (
 		// The State service must be available at all times, even
 		// before we can check macaroons, so we whitelist it.
 		"/lnrpc.State/SubscribeState": {},
+		"/lnrpc.State/GetState":       {},
 	}
 )
 
@@ -193,6 +194,31 @@ func (r *InterceptorChain) SetRPCActive() {
 	_ = r.ntfnServer.SendUpdate(r.state)
 }
 
+// rpcStateToWalletState converts rpcState to lnrpc.WalletState. Returns
+// WAITING_TO_START and an error on conversion error.
+func rpcStateToWalletState(state rpcState) (lnrpc.WalletState, error) {
+	const defaultState = lnrpc.WalletState_WAITING_TO_START
+	var walletState lnrpc.WalletState
+
+	switch state {
+	case waitingToStart:
+		walletState = lnrpc.WalletState_WAITING_TO_START
+	case walletNotCreated:
+		walletState = lnrpc.WalletState_NON_EXISTING
+	case walletLocked:
+		walletState = lnrpc.WalletState_LOCKED
+	case walletUnlocked:
+		walletState = lnrpc.WalletState_UNLOCKED
+	case rpcActive:
+		walletState = lnrpc.WalletState_RPC_ACTIVE
+
+	default:
+		return defaultState, fmt.Errorf("unknown wallet state %v", state)
+	}
+
+	return walletState, nil
+}
+
 // SubscribeState subscribes to the state of the wallet. The current wallet
 // state will always be delivered immediately.
 //
@@ -201,24 +227,14 @@ func (r *InterceptorChain) SubscribeState(req *lnrpc.SubscribeStateRequest,
 	stream lnrpc.State_SubscribeStateServer) error {
 
 	sendStateUpdate := func(state rpcState) error {
-		resp := &lnrpc.SubscribeStateResponse{}
-		switch state {
-		case waitingToStart:
-			resp.State = lnrpc.WalletState_WAITING_TO_START
-		case walletNotCreated:
-			resp.State = lnrpc.WalletState_NON_EXISTING
-		case walletLocked:
-			resp.State = lnrpc.WalletState_LOCKED
-		case walletUnlocked:
-			resp.State = lnrpc.WalletState_UNLOCKED
-		case rpcActive:
-			resp.State = lnrpc.WalletState_RPC_ACTIVE
-
-		default:
-			return fmt.Errorf("unknown wallet state %v", state)
+		walletState, err := rpcStateToWalletState(state)
+		if err != nil {
+			return err
 		}
 
-		return stream.Send(resp)
+		return stream.Send(&lnrpc.SubscribeStateResponse{
+			State: walletState,
+		})
 	}
 
 	// Subscribe to state updates.
@@ -262,6 +278,24 @@ func (r *InterceptorChain) SubscribeState(req *lnrpc.SubscribeStateRequest,
 	}
 }
 
+// GetState returns he current wallet state.
+func (r *InterceptorChain) GetState(_ context.Context,
+	req *lnrpc.GetStateRequest) (*lnrpc.GetStateResponse, error) {
+
+	r.RLock()
+	state := r.state
+	r.RUnlock()
+
+	walletState, err := rpcStateToWalletState(state)
+	if err != nil {
+		return nil, err
+	}
+
+	return &lnrpc.GetStateResponse{
+		State: walletState,
+	}, nil
+}
+
 // AddMacaroonService adds a macaroon service to the interceptor. After this is
 // done every RPC call made will have to pass a valid macaroon to be accepted.
 func (r *InterceptorChain) AddMacaroonService(svc *macaroons.Service) {