lnrpc: add StateService

lnd.go

@@ -349,6 +349,17 @@ func Main(cfg *Config, lisCfg ListenerCfg, shutdownChan <-chan struct{}) error {
 	interceptorChain := rpcperms.NewInterceptorChain(
 		rpcsLog, cfg.NoMacaroons, walletExists,
 	)
+	if err := interceptorChain.Start(); err != nil {
+		return err
+	}
+	defer func() {
+		err := interceptorChain.Stop()
+		if err != nil {
+			ltndLog.Warnf("error stopping RPC interceptor "+
+				"chain: %v", err)
+		}
+	}()
+
 	rpcServerOpts := interceptorChain.CreateServerOpts()
 	serverOpts = append(serverOpts, rpcServerOpts...)
 
@@ -358,6 +369,10 @@ func Main(cfg *Config, lisCfg ListenerCfg, shutdownChan <-chan struct{}) error {
 	// Register the WalletUnlockerService with the GRPC server.
 	lnrpc.RegisterWalletUnlockerServer(grpcServer, pwService)
 
+	// We'll also register the RPC interceptor chain as the StateServer, as
+	// it can be used to query for the current state of the wallet.
+	lnrpc.RegisterStateServer(grpcServer, interceptorChain)
+
 	// Initialize, and register our implementation of the gRPC interface
 	// exported by the rpcServer.
 	rpcServer := newRPCServer(
@@ -1239,7 +1254,7 @@ func startRestProxy(cfg *Config, rpcServer *rpcServer, restDialOpts []grpc.DialO
 	)
 	mux := proxy.NewServeMux(customMarshalerOption)
 
-	// Register both services with the REST proxy.
+	// Register our services with the REST proxy.
 	err := lnrpc.RegisterWalletUnlockerHandlerFromEndpoint(
 		ctx, mux, restProxyDest, restDialOpts,
 	)
@@ -1247,6 +1262,13 @@ func startRestProxy(cfg *Config, rpcServer *rpcServer, restDialOpts []grpc.DialO
 		return nil, err
 	}
 
+	err = lnrpc.RegisterStateHandlerFromEndpoint(
+		ctx, mux, restProxyDest, restDialOpts,
+	)
+	if err != nil {
+		return nil, err
+	}
+
 	err = rpcServer.RegisterWithRestProxy(
 		ctx, mux, restDialOpts, restProxyDest,
 	)