Simple Asset Loop out

assets/client.go

@@ -0,0 +1,101 @@
+package assets
+
+import (
+	"os"
+
+	"github.com/lightninglabs/taproot-assets/taprpc"
+	"github.com/lightninglabs/taproot-assets/taprpc/tapchannelrpc"
+	"github.com/lightningnetwork/lnd/macaroons"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	"gopkg.in/macaroon.v2"
+)
+
+var (
+	maxMsgRecvSize = grpc.MaxCallRecvMsgSize(400 * 1024 * 1024)
+)
+
+// TapdConfig is a struct that holds the configuration options to connect to a
+// taproot assets daemon.
+type TapdConfig struct {
+	Host         string `long:"host" description:"The host of the Tap daemon"`
+	MacaroonPath string `long:"macaroonpath" description:"Path to the admin macaroon"`
+	TLSPath      string `long:"tlspath" description:"Path to the TLS certificate"`
+}
+
+// DefaultTapdConfig returns a default configuration to connect to a taproot
+// assets daemon.
+func DefaultTapdConfig() *TapdConfig {
+	return &TapdConfig{
+		Host:         "",
+		MacaroonPath: "",
+		TLSPath:      "",
+	}
+}
+
+// NewTapdClient retusn a new taproot assets client.
+func NewTapdClient(config *TapdConfig) (*TapdClient, error) {
+	// Create the client connection to the server.
+	conn, err := getClientConn(config)
+	if err != nil {
+		return nil, err
+	}
+
+	// Create the TapdClient.
+	client := &TapdClient{
+		cc:                         conn,
+		TaprootAssetsClient:        taprpc.NewTaprootAssetsClient(conn),
+		TaprootAssetChannelsClient: tapchannelrpc.NewTaprootAssetChannelsClient(conn),
+	}
+
+	return client, nil
+}
+
+// Close closes the client connection to the server.
+func (c *TapdClient) Close() {
+	c.cc.Close()
+}
+
+// TapdClient is a client for the Tap daemon.
+type TapdClient struct {
+	cc *grpc.ClientConn
+	taprpc.TaprootAssetsClient
+	tapchannelrpc.TaprootAssetChannelsClient
+}
+
+func getClientConn(config *TapdConfig) (*grpc.ClientConn, error) {
+	// Load the specified TLS certificate and build transport credentials.
+	creds, err := credentials.NewClientTLSFromFile(config.TLSPath, "")
+	if err != nil {
+		return nil, err
+	}
+
+	// Load the specified macaroon file.
+	macBytes, err := os.ReadFile(config.MacaroonPath)
+	if err != nil {
+		return nil, err
+	}
+	mac := &macaroon.Macaroon{}
+	if err := mac.UnmarshalBinary(macBytes); err != nil {
+		return nil, err
+	}
+
+	macaroon, err := macaroons.NewMacaroonCredential(mac)
+	if err != nil {
+		return nil, err
+	}
+	// Create the DialOptions with the macaroon credentials.
+	opts := []grpc.DialOption{
+		grpc.WithTransportCredentials(creds),
+		grpc.WithPerRPCCredentials(macaroon),
+		grpc.WithDefaultCallOptions(maxMsgRecvSize),
+	}
+
+	// Dial the gRPC server.
+	conn, err := grpc.Dial(config.Host, opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	return conn, nil
+}

client.go

@@ -14,6 +14,7 @@ import (
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/lightninglabs/aperture/l402"
 	"github.com/lightninglabs/lndclient"
+	"github.com/lightninglabs/loop/assets"
 	"github.com/lightninglabs/loop/loopdb"
 	"github.com/lightninglabs/loop/swap"
 	"github.com/lightninglabs/loop/sweep"
@@ -94,6 +95,7 @@ type Client struct {
 	lndServices *lndclient.LndServices
 	sweeper     *sweep.Sweeper
 	executor    *executor
+	assetClient *assets.TapdClient
 
 	resumeReady chan struct{}
 	wg          sync.WaitGroup
@@ -121,6 +123,9 @@ type ClientConfig struct {
 	// Lnd is an instance of the lnd proxy.
 	Lnd *lndclient.LndServices
 
+	// AssetClient is an instance of the assets client.
+	AssetClient *assets.TapdClient
+
 	// MaxL402Cost is the maximum price we are willing to pay to the server
 	// for the token.
 	MaxL402Cost btcutil.Amount
@@ -273,6 +278,7 @@ func NewClient(dbDir string, loopDB loopdb.SwapStore,
 		errChan:      make(chan error),
 		clientConfig: *config,
 		lndServices:  cfg.Lnd,
+		assetClient:  cfg.AssetClient,
 		sweeper:      sweeper,
 		executor:     executor,
 		resumeReady:  make(chan struct{}),
@@ -453,7 +459,7 @@ func (s *Client) Run(ctx context.Context, statusChan chan<- SwapInfo) error {
 func (s *Client) resumeSwaps(ctx context.Context,
 	loopOutSwaps []*loopdb.LoopOut, loopInSwaps []*loopdb.LoopIn) {
 
-	swapCfg := newSwapConfig(s.lndServices, s.Store, s.Server)
+	swapCfg := newSwapConfig(s.lndServices, s.Store, s.Server, s.assetClient)
 
 	for _, pend := range loopOutSwaps {
 		if pend.State().State.Type() != loopdb.StateTypePending {
@@ -523,7 +529,14 @@ func (s *Client) LoopOut(globalCtx context.Context,
 	}
 
 	// Create a new swap object for this swap.
-	swapCfg := newSwapConfig(s.lndServices, s.Store, s.Server)
+	swapCfg := newSwapConfig(s.lndServices, s.Store, s.Server, s.assetClient)
+
+	// Verify that if we have an asset id set, we have a valid asset client
+	// to use.
+	if request.AssetId != nil && s.assetClient == nil {
+		return nil, errors.New("asset id set but no asset client provided")
+	}
+
 	initResult, err := newLoopOutSwap(
 		globalCtx, swapCfg, initiationHeight, request,
 	)
@@ -682,7 +695,7 @@ func (s *Client) LoopIn(globalCtx context.Context,
 
 	// Create a new swap object for this swap.
 	initiationHeight := s.executor.height()
-	swapCfg := newSwapConfig(s.lndServices, s.Store, s.Server)
+	swapCfg := newSwapConfig(s.lndServices, s.Store, s.Server, s.assetClient)
 	initResult, err := newLoopInSwap(
 		globalCtx, swapCfg, initiationHeight, request,
 	)

cmd/loop/loopout.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"encoding/hex"
 	"fmt"
 	"math"
 	"strconv"
@@ -101,6 +102,18 @@ var loopOutCommand = cli.Command{
 				"payment might be retried, the actual total " +
 				"time may be longer",
 		},
+		cli.StringFlag{
+			Name: "asset_id",
+			Usage: "the asset ID of the asset to loop out, " +
+				"if this is set, the loop daemon will require a connection " +
+				"to a taproot assets daemon",
+		},
+		cli.StringFlag{
+			Name: "asset_edge_node",
+			Usage: "the pubkey of the edge node of the asset to loop out, " +
+				"this is required if the taproot assets daemon has multiple " +
+				"channels of the given asset id with different edge nodes",
+		},
 		forceFlag,
 		labelFlag,
 		verboseFlag,
@@ -186,6 +199,22 @@ func loopOut(ctx *cli.Context) error {
 		}
 	}
 
+	var assetId []byte
+	if ctx.IsSet("asset_id") {
+		assetId, err = hex.DecodeString(ctx.String("asset_id"))
+		if err != nil {
+			return err
+		}
+	}
+
+	var assetEdgeNode []byte
+	if ctx.IsSet("asset_edge_node") {
+		assetEdgeNode, err = hex.DecodeString(ctx.String("asset_edge_node"))
+		if err != nil {
+			return err
+		}
+	}
+
 	client, cleanup, err := getClient(ctx)
 	if err != nil {
 		return err
@@ -281,6 +310,8 @@ func loopOut(ctx *cli.Context) error {
 		Label:                   label,
 		Initiator:               defaultInitiator,
 		PaymentTimeout:          uint32(paymentTimeout),
+		AssetId:                 assetId,
+		AssetEdgeNode:           assetEdgeNode,
 	})
 	if err != nil {
 		return err