Merge pull request #1545 from lightninglabs/bump-psbt-maxfeeratio

tapd: bump maxFeeRatio for funded psbts

Author: ffranr

docs/release-notes/release-notes-0.7.0.md

@@ -189,6 +189,14 @@
   [PR](https://github.com/lightninglabs/taproot-assets/pull/1640) addresses the
   issue.
 
+- A new configuration is now available which controls the max ratio of fees that
+  each anchor transaction pays. This is important because given the nature of
+  the small taproot-assets anchors we might want to allow for fees to be greater
+  than the anchor amount itself, which is helpful in high fee environment where
+  pulling in extra inputs might not be preferred. It is exposed via the flag
+  `wallet.psbt-max-fee-ratio` and is introduced by
+  [PR #1545](https://github.com/lightninglabs/taproot-assets/pull/1545).
+
 ## RPC Updates
 
 ## tapcli Updates

lndservices/wallet_anchor.go

@@ -21,17 +21,59 @@ import (
 	"github.com/lightningnetwork/lnd/lnwallet/chainfee"
 )
 
+// DefaultPsbtMaxFeeRatio is the maximum ratio between fees paid and total
+// output amount produced. Since taproot assets can be anchored to outpoints
+// that may carry relatively small bitcoin amounts, we want to bump the allowed
+// ratio between fees paid and total produced output amount. This can prove
+// useful in high fee environments where we'd otherwise fail to fund the psbt.
+const DefaultPsbtMaxFeeRatio = 0.75
+
 // LndRpcWalletAnchor is an implementation of the tapgarden.WalletAnchor
 // interfaced backed by an active remote lnd node.
 type LndRpcWalletAnchor struct {
 	lnd *lndclient.LndServices
+	cfg *WalletAnchorConfig
+}
+
+// WalletAnchorConfig is a configuration for the wallet anchor.
+type WalletAnchorConfig struct {
+	psbtMaxFeeRatio float64
+}
+
+// defaultWalletAnchorConfig returns the default configuration for the wallet
+// anchor.
+func defaultWalletAnchorConfig() *WalletAnchorConfig {
+	return &WalletAnchorConfig{
+		psbtMaxFeeRatio: DefaultPsbtMaxFeeRatio,
+	}
+}
+
+// WalletAnchorOption is an optional argument that modifies the wallet anchor
+// configuration.
+type WalletAnchorOption func(cfg *WalletAnchorConfig)
+
+// WithPsbtMaxFeeRatio is an optional argument that provides a custom psbt
+// max fee ratio.
+func WithPsbtMaxFeeRatio(val float64) WalletAnchorOption {
+	return func(cfg *WalletAnchorConfig) {
+		cfg.psbtMaxFeeRatio = val
+	}
 }
 
 // NewLndRpcWalletAnchor returns a new wallet anchor instance using the passed
 // lnd node.
-func NewLndRpcWalletAnchor(lnd *lndclient.LndServices) *LndRpcWalletAnchor {
+func NewLndRpcWalletAnchor(lnd *lndclient.LndServices,
+	opts ...WalletAnchorOption) *LndRpcWalletAnchor {
+
+	cfg := defaultWalletAnchorConfig()
+
+	for _, opt := range opts {
+		opt(cfg)
+	}
+
 	return &LndRpcWalletAnchor{
 		lnd: lnd,
+		cfg: cfg,
 	}
 }
 
@@ -82,8 +124,9 @@ func (l *LndRpcWalletAnchor) FundPsbt(ctx context.Context, packet *psbt.Packet,
 			Fees: &walletrpc.FundPsbtRequest_SatPerKw{
 				SatPerKw: uint64(feeRate),
 			},
-			MinConfs:   int32(minConfs),
-			ChangeType: defaultChangeType,
+			MinConfs:    int32(minConfs),
+			ChangeType:  defaultChangeType,
+			MaxFeeRatio: l.cfg.psbtMaxFeeRatio,
 		},
 	)
 	if err != nil {

sample-tapd.conf

@@ -407,6 +407,10 @@
 ; the syncer cache. (default: 10240)
 ; universe.multiverse-caches.root-node-page-cache-size=10240
 
+[wallet]
+; The maximum ratio of fees to total output amount for the wallet funded PSBTs.
+; Value must be a valid float ranging from 0.00 to 1.00.
+; wallet.psbt-max-fee-ratio=0.75
 
 [address]
 

tapcfg/config.go

@@ -22,6 +22,7 @@ import (
 	"github.com/lightninglabs/lndclient"
 	tap "github.com/lightninglabs/taproot-assets"
 	"github.com/lightninglabs/taproot-assets/fn"
+	"github.com/lightninglabs/taproot-assets/lndservices"
 	"github.com/lightninglabs/taproot-assets/monitoring"
 	"github.com/lightninglabs/taproot-assets/proof"
 	"github.com/lightninglabs/taproot-assets/rfq"
@@ -143,6 +144,10 @@ const (
 	// defaultMailboxAuthTimeout is the default timeout we'll use for
 	// mailbox message retrieval client authentication.
 	defaultMailboxAuthTimeout = 10 * time.Second
+
+	// DefaultPsbtMaxFeeRatio is the default maximum for fees to total
+	// output amount ratio to use when funding PSBTs.
+	DefaultPsbtMaxFeeRatio = lndservices.DefaultPsbtMaxFeeRatio
 )
 
 var (
@@ -280,6 +285,17 @@ type LndConfig struct {
 	RPCTimeout time.Duration `long:"rpctimeout" description:"The timeout to use for RPC requests to lnd; a sufficiently long duration should be chosen to avoid issues with slow responses. Valid time units are {s, m, h}."`
 }
 
+// WalletConfig is the config that contains wallet related configurations.
+type WalletConfig struct {
+	// PsbtMaxFeeRatio is the maximum fees to total output amount ratio to
+	// use when funding PSBTs for asset transfers. Since taproot assets can
+	// be anchored to outpoints that may carry relatively small bitcoin
+	// amounts it is useful to pick a high value for this argument as in
+	// high fee environments the total fees paid may outweigh the anchor
+	// amount. The allowed values for this argument range from 0.00 to 1.00.
+	PsbtMaxFeeRatio float64 `long:"psbt-max-fee-ratio" description:"The maximum fees to total output amount ratio to use when funding PSBTs for asset transfers. Value must be between 0.00 and 1.00"`
+}
+
 // UniverseConfig is the config that houses any Universe related config
 // values.
 type UniverseConfig struct {
@@ -363,6 +379,8 @@ type Config struct {
 
 	Universe *UniverseConfig `group:"universe" namespace:"universe"`
 
+	Wallet *WalletConfig `group:"wallet" namespace:"wallet"`
+
 	AddrBook *AddrBookConfig `group:"address" namespace:"address"`
 
 	Channel *ChannelConfig `group:"channel" namespace:"channel"`
@@ -473,6 +491,9 @@ func DefaultConfig() Config {
 			SupplyIgnoreCacheSize:           tapdb.DefaultNegativeLookupCacheSize,
 			DisableSupplyVerifierChainWatch: false,
 		},
+		Wallet: &WalletConfig{
+			PsbtMaxFeeRatio: DefaultPsbtMaxFeeRatio,
+		},
 		AddrBook: &AddrBookConfig{
 			DisableSyncer: false,
 		},
@@ -932,6 +953,16 @@ func ValidateConfig(cfg Config, cfgLogger btclog.Logger) (*Config, error) {
 		cfg.ReOrgSafeDepth = testnetDefaultReOrgSafeDepth
 	}
 
+	// Let's validate that the wallet's psbt max fee ratio is within the
+	// expected range.
+	switch {
+	case cfg.Wallet.PsbtMaxFeeRatio < 0.00:
+		fallthrough
+	case cfg.Wallet.PsbtMaxFeeRatio > 1.00:
+		return nil, fmt.Errorf("psbt-max-fee-ratio must be set in " +
+			"range of 0.00 to 1.00")
+	}
+
 	// All good, return the sanitized result.
 	return &cfg, nil
 }

tapcfg/server.go

@@ -108,7 +108,10 @@ func genServerConfig(cfg *Config, cfgLogger btclog.Logger,
 	assetStore := tapdb.NewAssetStore(assetDB, metaDB, defaultClock, dbType)
 
 	keyRing := lndservices.NewLndRpcKeyRing(lndServices)
-	walletAnchor := lndservices.NewLndRpcWalletAnchor(lndServices)
+	walletAnchor := lndservices.NewLndRpcWalletAnchor(
+		lndServices,
+		lndservices.WithPsbtMaxFeeRatio(cfg.Wallet.PsbtMaxFeeRatio),
+	)
 	chainBridge := lndservices.NewLndRpcChainBridge(lndServices, assetStore)
 	msgTransportClient := lndservices.NewLndMsgTransportClient(lndServices)
 	lndRouterClient := lndservices.NewLndRouterClient(lndServices)