wallet: add keyCount metric

Signed-off-by: Gustavo Chain <[email protected]>

Author: qustavo

collectors/wallet_collector.go

@@ -30,6 +30,11 @@ type WalletCollector struct {
 	confirmedBalanceDesc   *prometheus.Desc
 	unconfirmedBalanceDesc *prometheus.Desc
 
+	// We'll use one gauge to keep track of both internal and external key
+	// count.
+	keyCountDesc *prometheus.Desc
+
+	// We'll use two gauges to keep track of the accounts internal and external
 	// errChan is a channel that we send any errors that we encounter into.
 	// This channel should be buffered so that it does not block sends.
 	errChan chan<- error
@@ -39,6 +44,8 @@ type WalletCollector struct {
 func NewWalletCollector(lnd *lndclient.LndServices,
 	errChan chan<- error) *WalletCollector {
 
+	// these labels are specific for key_count metrics
+	keyCountLabels := []string{"account_name", "address_type", "derivation_path", "key_type"}
 	return &WalletCollector{
 		lnd: lnd,
 		numUtxosConfDesc: prometheus.NewDesc(
@@ -71,6 +78,12 @@ func NewWalletCollector(lnd *lndclient.LndServices,
 			"unconfirmed wallet balance",
 			nil, nil,
 		),
+		keyCountDesc: prometheus.NewDesc(
+			"lnd_wallet_key_count",
+			"wallet key count",
+			keyCountLabels, nil,
+		),
+
 		errChan: errChan,
 	}
 }
@@ -88,6 +101,7 @@ func (u *WalletCollector) Describe(ch chan<- *prometheus.Desc) {
 	ch <- u.avgUtxoSizeDesc
 	ch <- u.confirmedBalanceDesc
 	ch <- u.unconfirmedBalanceDesc
+	ch <- u.keyCountDesc
 }
 
 // Collect is called by the Prometheus registry when collecting metrics.
@@ -169,4 +183,30 @@ func (u *WalletCollector) Collect(ch chan<- prometheus.Metric) {
 		u.unconfirmedBalanceDesc, prometheus.GaugeValue,
 		float64(walletBal.Unconfirmed),
 	)
+
+	accounts, err := u.lnd.WalletKit.ListAccounts(context.Background(), "", 0)
+	if err != nil {
+		u.errChan <- fmt.Errorf("WalletCollector ListAccounts"+
+			"failed with: %v", err)
+		return
+	}
+
+	for _, account := range accounts {
+		name, addrType, path := account.GetName(),
+			account.GetAddressType().String(), account.GetDerivationPath()
+
+			// internal key count.
+		ch <- prometheus.MustNewConstMetric(
+			u.keyCountDesc, prometheus.CounterValue,
+			float64(account.InternalKeyCount),
+			name, addrType, path, "internal",
+		)
+
+		// external key count.
+		ch <- prometheus.MustNewConstMetric(
+			u.keyCountDesc, prometheus.CounterValue,
+			float64(account.ExternalKeyCount),
+			name, addrType, path, "external",
+		)
+	}
 }