collectors: add waiting close and force close balance tracking

This commit extends the channels collector with two additional metrics
to be able to monitor channel balances waiting to close and channel
balances currently in limbo due to being force closed.

collectors/channels_collector.go

@@ -13,8 +13,10 @@ import (
 
 // ChannelsCollector is a collector that keeps track of channel information.
 type ChannelsCollector struct {
-	channelBalanceDesc        *prometheus.Desc
-	pendingChannelBalanceDesc *prometheus.Desc
+	channelBalanceDesc           *prometheus.Desc
+	pendingChannelBalanceDesc    *prometheus.Desc
+	pendingForceCloseBalanceDesc *prometheus.Desc
+	waitingCloseBalanceDesc      *prometheus.Desc
 
 	incomingChanSatDesc *prometheus.Desc
 	outgoingChanSatDesc *prometheus.Desc
@@ -70,7 +72,16 @@ func NewChannelsCollector(lnd lndclient.LightningClient, errChan chan<- error,
 			"total balance of all pending channels in satoshis",
 			nil, nil,
 		),
-
+		pendingForceCloseBalanceDesc: prometheus.NewDesc(
+			"lnd_channels_pending_force_close_balance_sat",
+			"force closed channel balances in satoshis",
+			append(labels, "blocks_until_maturity"), nil,
+		),
+		waitingCloseBalanceDesc: prometheus.NewDesc(
+			"lnd_channels_waiting_close_balance_sat",
+			"waiting to close channel balances in satoshis",
+			labels, nil,
+		),
 		incomingChanSatDesc: prometheus.NewDesc(
 			"lnd_channels_bandwidth_incoming_sat",
 			"total available incoming channel bandwidth within this channel",
@@ -177,6 +188,8 @@ func NewChannelsCollector(lnd lndclient.LightningClient, errChan chan<- error,
 func (c *ChannelsCollector) Describe(ch chan<- *prometheus.Desc) {
 	ch <- c.channelBalanceDesc
 	ch <- c.pendingChannelBalanceDesc
+	ch <- c.pendingForceCloseBalanceDesc
+	ch <- c.waitingCloseBalanceDesc
 
 	ch <- c.incomingChanSatDesc
 	ch <- c.outgoingChanSatDesc
@@ -204,6 +217,22 @@ func (c *ChannelsCollector) Describe(ch chan<- *prometheus.Desc) {
 	ch <- c.inboundFee
 }
 
+func anchorStateToString(state lndclient.ForceCloseAnchorState) string {
+	switch state {
+	case lndclient.ForceCloseAnchorStateLimbo:
+		return "Limbo"
+
+	case lndclient.ForceCloseAnchorStateRecovered:
+		return "Recovered"
+
+	case lndclient.ForceCloseAnchorStateLost:
+		return "Lost"
+
+	default:
+		return "Unknown"
+	}
+}
+
 // Collect is called by the Prometheus registry when collecting metrics.
 //
 // NOTE: Part of the prometheus.Collector interface.
@@ -379,6 +408,33 @@ func (c *ChannelsCollector) Collect(ch chan<- prometheus.Metric) {
 		"waiting_close",
 	)
 
+	for _, forceClose := range pendingChannelsResp.PendingForceClose {
+		// Labels are: "chan_id", "status", "initiator", "peer",
+		// "blocks_until_maturity". We'll use status to hold the anchor
+		// state.
+		ch <- prometheus.MustNewConstMetric(
+			c.pendingForceCloseBalanceDesc, prometheus.GaugeValue,
+			float64(forceClose.RecoveredBalance),
+			forceClose.ChannelPoint.String(),
+			anchorStateToString(forceClose.AnchorState),
+			forceClose.ChannelInitiator.String(),
+			forceClose.PubKeyBytes.String(),
+			fmt.Sprintf("%d", forceClose.BlocksUntilMaturity),
+		)
+	}
+
+	for _, waitingClose := range pendingChannelsResp.WaitingClose {
+		// Labels are: "chan_id", "status", "initiator", "peer".
+		ch <- prometheus.MustNewConstMetric(
+			c.waitingCloseBalanceDesc, prometheus.GaugeValue,
+			float64(waitingClose.LocalBalance),
+			waitingClose.ChannelPoint.String(),
+			waitingClose.ChanStatusFlags,
+			waitingClose.ChannelInitiator.String(),
+			waitingClose.PubKeyBytes.String(),
+		)
+	}
+
 	// Get the list of closed channels.
 	closedChannelsResp, err := c.lnd.ClosedChannels(context.Background())
 	if err != nil {