itest: use node.rpc namespace inside harness net

This commit adds a new struct RPCClients to better handle rpc clients.
A private field, rpc, is added to HarnessNode to prevent direct access
to its clients. Inside RPCClients, all clients are exported in case a
test case need access to a specific client.

lntest/harness_node.go

@@ -296,8 +296,8 @@ type HarnessNode struct {
 	PubKey    [33]byte
 	PubKeyStr string
 
-	cmd     *exec.Cmd
+	// rpc holds a list of RPC clients.
-	logFile *os.File
+	rpc *RPCClients
 
 	// chanWatchRequests receives a request for watching a particular event
 	// for a given channel.
@@ -317,41 +317,50 @@ type HarnessNode struct {
 	// node and the outpoint.
 	policyUpdates policyUpdateMap
 
-	// runCtx is a context with cancel method. It's used to signal when the
-	// node needs to quit, and used as the parent context when spawning
-	// children contexts for RPC requests.
-	runCtx context.Context
-	cancel context.CancelFunc
-
-	wg sync.WaitGroup
-
-	lnrpc.LightningClient
-
-	lnrpc.WalletUnlockerClient
-
-	invoicesrpc.InvoicesClient
-
-	// SignerClient cannot be embedded because the name collisions of the
-	// methods SignMessage and VerifyMessage.
-	SignerClient signrpc.SignerClient
-
-	// conn is the underlying connection to the grpc endpoint of the node.
-	conn *grpc.ClientConn
-
-	// RouterClient, WalletKitClient, WatchtowerClient cannot be embedded,
-	// because a name collision would occur with LightningClient.
-	RouterClient     routerrpc.RouterClient
-	WalletKitClient  walletrpc.WalletKitClient
-	Watchtower       watchtowerrpc.WatchtowerClient
-	WatchtowerClient wtclientrpc.WatchtowerClientClient
-	StateClient      lnrpc.StateClient
-
 	// backupDbDir is the path where a database backup is stored, if any.
 	backupDbDir string
 
 	// postgresDbName is the name of the postgres database where lnd data is
 	// stored in.
 	postgresDbName string
+
+	// runCtx is a context with cancel method. It's used to signal when the
+	// node needs to quit, and used as the parent context when spawning
+	// children contexts for RPC requests.
+	runCtx context.Context
+	cancel context.CancelFunc
+
+	wg      sync.WaitGroup
+	cmd     *exec.Cmd
+	logFile *os.File
+
+	// TODO(yy): remove
+	lnrpc.LightningClient
+	lnrpc.WalletUnlockerClient
+	invoicesrpc.InvoicesClient
+	SignerClient     signrpc.SignerClient
+	RouterClient     routerrpc.RouterClient
+	WalletKitClient  walletrpc.WalletKitClient
+	Watchtower       watchtowerrpc.WatchtowerClient
+	WatchtowerClient wtclientrpc.WatchtowerClientClient
+	StateClient      lnrpc.StateClient
+}
+
+// RPCClients wraps a list of RPC clients into a single struct for easier
+// access.
+type RPCClients struct {
+	// conn is the underlying connection to the grpc endpoint of the node.
+	conn *grpc.ClientConn
+
+	LN               lnrpc.LightningClient
+	WalletUnlocker   lnrpc.WalletUnlockerClient
+	Invoice          invoicesrpc.InvoicesClient
+	Signer           signrpc.SignerClient
+	Router           routerrpc.RouterClient
+	WalletKit        walletrpc.WalletKitClient
+	Watchtower       watchtowerrpc.WatchtowerClient
+	WatchtowerClient wtclientrpc.WatchtowerClientClient
+	State            lnrpc.StateClient
 }
 
 // Assert *HarnessNode implements the lnrpc.LightningClient interface.
@@ -719,16 +728,20 @@ func (hn *HarnessNode) start(lndBinary string, lndError chan<- error,
 		return err
 	}
 
+	// Init all the RPC clients.
+	hn.initRPCClients(conn)
+
 	// If the node was created with a seed, we will need to perform an
 	// additional step to unlock the wallet. The connection returned will
 	// only use the TLS certs, and can only perform operations necessary to
 	// unlock the daemon.
 	if hn.Cfg.HasSeed {
+		// TODO(yy): remove
 		hn.WalletUnlockerClient = lnrpc.NewWalletUnlockerClient(conn)
 		return nil
 	}
 
-	return hn.initLightningClient(conn)
+	return hn.initLightningClient()
 }
 
 // WaitUntilStarted waits until the wallet state flips from "WAITING_TO_START".
@@ -757,7 +770,7 @@ func (hn *HarnessNode) waitForState(conn grpc.ClientConnInterface,
 	predicate func(state lnrpc.WalletState) bool) error {
 
 	stateClient := lnrpc.NewStateClient(conn)
-	ctx, cancel := context.WithCancel(hn.runCtx)
+	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
 	stateStream, err := stateClient.SubscribeState(
@@ -820,16 +833,21 @@ func (hn *HarnessNode) WaitUntilLeader(timeout time.Duration) error {
 		return err
 	}
 
+	// Init all the RPC clients.
+	hn.initRPCClients(conn)
+
 	// If the node was created with a seed, we will need to perform an
 	// additional step to unlock the wallet. The connection returned will
 	// only use the TLS certs, and can only perform operations necessary to
 	// unlock the daemon.
 	if hn.Cfg.HasSeed {
+		// TODO(yy): remove
 		hn.WalletUnlockerClient = lnrpc.NewWalletUnlockerClient(conn)
+
 		return nil
 	}
 
-	return hn.initLightningClient(conn)
+	return hn.initLightningClient()
 }
 
 // initClientWhenReady waits until the main gRPC server is detected as active,
@@ -847,7 +865,10 @@ func (hn *HarnessNode) initClientWhenReady(timeout time.Duration) error {
 		return err
 	}
 
-	return hn.initLightningClient(conn)
+	// Init all the RPC clients.
+	hn.initRPCClients(conn)
+
+	return hn.initLightningClient()
 }
 
 // Init initializes a harness node by passing the init request via rpc. After
@@ -889,7 +910,10 @@ func (hn *HarnessNode) Init(
 		return nil, err
 	}
 
-	return response, hn.initLightningClient(conn)
+	// Init all the RPC clients.
+	hn.initRPCClients(conn)
+
+	return response, hn.initLightningClient()
 }
 
 // InitChangePassword initializes a harness node by passing the change password
@@ -932,7 +956,10 @@ func (hn *HarnessNode) InitChangePassword(
 		return nil, err
 	}
 
-	return response, hn.initLightningClient(conn)
+	// Init all the RPC clients.
+	hn.initRPCClients(conn)
+
+	return response, hn.initLightningClient()
 }
 
 // Unlock attempts to unlock the wallet of the target HarnessNode. This method
@@ -945,7 +972,8 @@ func (hn *HarnessNode) Unlock(unlockReq *lnrpc.UnlockWalletRequest) error {
 
 	// Otherwise, we'll need to unlock the node before it's able to start
 	// up properly.
-	if _, err := hn.UnlockWallet(ctxt, unlockReq); err != nil {
+	_, err := hn.rpc.WalletUnlocker.UnlockWallet(ctxt, unlockReq)
+	if err != nil {
 		return err
 	}
 
@@ -960,7 +988,7 @@ func (hn *HarnessNode) waitTillServerStarted() error {
 	ctxt, cancel := context.WithTimeout(hn.runCtx, NodeStartTimeout)
 	defer cancel()
 
-	client, err := hn.StateClient.SubscribeState(
+	client, err := hn.rpc.State.SubscribeState(
 		ctxt, &lnrpc.SubscribeStateRequest{},
 	)
 	if err != nil {
@@ -978,17 +1006,33 @@ func (hn *HarnessNode) waitTillServerStarted() error {
 			return nil
 		}
 	}
-
 }
 
-// initLightningClient constructs the grpc LightningClient from the given client
+// initRPCClients initializes a list of RPC clients for the node.
-// connection and subscribes the harness node to graph topology updates.
+func (hn *HarnessNode) initRPCClients(c *grpc.ClientConn) {
-// This method also spawns a lightning network watcher for this node,
+	hn.rpc = &RPCClients{
-// which watches for topology changes.
+		conn:             c,
-func (hn *HarnessNode) initLightningClient(conn *grpc.ClientConn) error {
+		LN:               lnrpc.NewLightningClient(c),
+		Invoice:          invoicesrpc.NewInvoicesClient(c),
+		Router:           routerrpc.NewRouterClient(c),
+		WalletKit:        walletrpc.NewWalletKitClient(c),
+		WalletUnlocker:   lnrpc.NewWalletUnlockerClient(c),
+		Watchtower:       watchtowerrpc.NewWatchtowerClient(c),
+		WatchtowerClient: wtclientrpc.NewWatchtowerClientClient(c),
+		Signer:           signrpc.NewSignerClient(c),
+		State:            lnrpc.NewStateClient(c),
+	}
+}
+
+// initLightningClient blocks until the lnd server is fully started and
+// subscribes the harness node to graph topology updates. This method also
+// spawns a lightning network watcher for this node, which watches for topology
+// changes.
+func (hn *HarnessNode) initLightningClient() error {
+	// TODO(yy): remove
 	// Construct the LightningClient that will allow us to use the
 	// HarnessNode directly for normal rpc operations.
-	hn.conn = conn
+	conn := hn.rpc.conn
 	hn.LightningClient = lnrpc.NewLightningClient(conn)
 	hn.InvoicesClient = invoicesrpc.NewInvoicesClient(conn)
 	hn.RouterClient = routerrpc.NewRouterClient(conn)
@@ -1021,8 +1065,7 @@ func (hn *HarnessNode) initLightningClient(conn *grpc.ClientConn) error {
 // FetchNodeInfo queries an unlocked node to retrieve its public key.
 func (hn *HarnessNode) FetchNodeInfo() error {
 	// Obtain the lnid of this node for quick identification purposes.
-	ctxb := context.Background()
+	info, err := hn.rpc.LN.GetInfo(hn.runCtx, &lnrpc.GetInfoRequest{})
-	info, err := hn.GetInfo(ctxb, &lnrpc.GetInfoRequest{})
 	if err != nil {
 		return err
 	}
@@ -1163,21 +1206,23 @@ func (hn *HarnessNode) stop() error {
 		return nil
 	}
 
-	// If start() failed before creating a client, we will just wait for the
+	// If start() failed before creating clients, we will just wait for the
 	// child process to die.
-	if hn.LightningClient != nil {
+	if hn.rpc != nil && hn.rpc.LN != nil {
-		// Don't watch for error because sometimes the RPC connection gets
+		// Don't watch for error because sometimes the RPC connection
-		// closed before a response is returned.
+		// gets closed before a response is returned.
 		req := lnrpc.StopRequest{}
 
 		err := wait.NoError(func() error {
-			_, err := hn.LightningClient.StopDaemon(hn.runCtx, &req)
+			_, err := hn.rpc.LN.StopDaemon(hn.runCtx, &req)
 			switch {
 			case err == nil:
 				return nil
 
 			// Try again if a recovery/rescan is in progress.
-			case strings.Contains(err.Error(), "recovery in progress"):
+			case strings.Contains(
+				err.Error(), "recovery in progress",
+			):
 				return err
 
 			default:
@@ -1217,8 +1262,8 @@ func (hn *HarnessNode) stop() error {
 	hn.WatchtowerClient = nil
 
 	// Close any attempts at further grpc connections.
-	if hn.conn != nil {
+	if hn.rpc.conn != nil {
-		err := status.Code(hn.conn.Close())
+		err := status.Code(hn.rpc.conn.Close())
 		switch err {
 		case codes.OK:
 			return nil
@@ -1497,7 +1542,7 @@ func (hn *HarnessNode) WaitForBlockchainSync() error {
 	defer ticker.Stop()
 
 	for {
-		resp, err := hn.GetInfo(ctxt, &lnrpc.GetInfoRequest{})
+		resp, err := hn.rpc.LN.GetInfo(ctxt, &lnrpc.GetInfoRequest{})
 		if err != nil {
 			return err
 		}
@@ -1525,7 +1570,7 @@ func (hn *HarnessNode) WaitForBalance(expectedBalance btcutil.Amount,
 
 	var lastBalance btcutil.Amount
 	doesBalanceMatch := func() bool {
-		balance, err := hn.WalletBalance(hn.runCtx, req)
+		balance, err := hn.rpc.LN.WalletBalance(hn.runCtx, req)
 		if err != nil {
 			return false
 		}
@@ -1695,7 +1740,7 @@ func (hn *HarnessNode) newTopologyClient(
 	ctx context.Context) (topologyClient, error) {
 
 	req := &lnrpc.GraphTopologySubscription{}
-	client, err := hn.SubscribeChannelGraph(ctx, req)
+	client, err := hn.rpc.LN.SubscribeChannelGraph(ctx, req)
 	if err != nil {
 		return nil, fmt.Errorf("%s(%d): unable to create topology "+
 			"client: %v (%s)", hn.Name(), hn.NodeID, err,
@@ -1765,7 +1810,7 @@ func (hn *HarnessNode) receiveTopologyClientStream(
 		default:
 			// An expected error is returned, return and leave it
 			// to be handled by the caller.
-			return fmt.Errorf("graph subscription err: %v", err)
+			return fmt.Errorf("graph subscription err: %w", err)
 		}
 
 		// Send the update or quit.
@@ -1814,7 +1859,7 @@ func (hn *HarnessNode) getChannelPolicies(include bool) policyUpdateMap {
 	ctxt, cancel := context.WithTimeout(hn.runCtx, DefaultTimeout)
 	defer cancel()
 
-	graph, err := hn.DescribeGraph(ctxt, &lnrpc.ChannelGraphRequest{
+	graph, err := hn.rpc.LN.DescribeGraph(ctxt, &lnrpc.ChannelGraphRequest{
 		IncludeUnannounced: include,
 	})
 	if err != nil {