Merge pull request #5206 from carlaKC/4987-heightexpirywatcher

invoices: add height based expiry watcher

config.go

@@ -347,6 +347,8 @@ type Config struct {
 
 	GcCanceledInvoicesOnTheFly bool `long:"gc-canceled-invoices-on-the-fly" description:"If true, we'll delete newly canceled invoices on the fly."`
 
+	Invoices *lncfg.Invoices `group:"invoices" namespace:"invoices"`
+
 	Routing *lncfg.Routing `group:"routing" namespace:"routing"`
 
 	Gossip *lncfg.Gossip `group:"gossip" namespace:"gossip"`
@@ -532,6 +534,9 @@ func DefaultConfig() Config {
 			MaxChannelUpdateBurst: discovery.DefaultMaxChannelUpdateBurst,
 			ChannelUpdateInterval: discovery.DefaultChannelUpdateInterval,
 		},
+		Invoices: &lncfg.Invoices{
+			HoldExpiryDelta: lncfg.DefaultHoldInvoiceExpiryDelta,
+		},
 		MaxOutgoingCltvExpiry:   htlcswitch.DefaultMaxOutgoingCltvExpiry,
 		MaxChannelFeeAllocation: htlcswitch.DefaultMaxLinkFeeAllocation,
 		MaxCommitFeeRateAnchors: lnwallet.DefaultAnchorsCommitMaxFeeRateSatPerVByte,
@@ -1389,6 +1394,18 @@ func ValidateConfig(cfg Config, usageMessage string,
 		return nil, err
 	}
 
+	// Log a warning if our expiry delta is not greater than our incoming
+	// broadcast delta. We do not fail here because this value may be set
+	// to zero to intentionally keep lnd's behavior unchanged from when we
+	// didn't auto-cancel these invoices.
+	if cfg.Invoices.HoldExpiryDelta <= lncfg.DefaultIncomingBroadcastDelta {
+		ltndLog.Warnf("Invoice hold expiry delta: %v <= incoming "+
+			"delta: %v, accepted hold invoices will force close "+
+			"channels if they are not canceled manually",
+			cfg.Invoices.HoldExpiryDelta,
+			lncfg.DefaultIncomingBroadcastDelta)
+	}
+
 	// Validate the subconfigs for workers, caches, and the tower client.
 	err = lncfg.Validate(
 		cfg.Workers,