From 3c8aef1cb00d4cde72c5da6e8bbda464c14afa34 Mon Sep 17 00:00:00 2001
From: Ben Wilson <ben@z.cash>
Date: Thu, 14 Nov 2019 12:22:22 -0500
Subject: [PATCH] Addded metrics for getchaintips

---
 collector.go |  7 +++++++
 main.go      | 28 ++++++++++++++++++++++++++++
 rpc.go       | 11 +++++++++++
 3 files changed, 46 insertions(+)

diff --git a/collector.go b/collector.go
index cd989c4..d5d0932 100644
--- a/collector.go
+++ b/collector.go
@@ -27,6 +27,12 @@ var (
 		[]string{
 			"type",
 		})
+	zcashdChainTips = prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "zcash_chain_tip",
+			Help: "Return information about all known tips in the block tree, including the main chain as well as orphaned branches."},
+		[]string{"height", "hash", "branchlen", "status"},
+	)
 )
 
 // ZCASH_PEERS = Gauge("zcash_peers", "Number of peers")
@@ -61,4 +67,5 @@ func init() {
 	prometheus.MustRegister(zcashdMemPoolBytes)
 	prometheus.MustRegister(zcashdMemPoolUsage)
 	prometheus.MustRegister(zcashdWalletBalance)
+	prometheus.MustRegister(zcashdChainTips)
 }
diff --git a/main.go b/main.go
index 25065cc..fb6545f 100644
--- a/main.go
+++ b/main.go
@@ -55,6 +55,7 @@ func main() {
 	go getBlockchainInfo()
 	go getMemPoolInfo()
 	go getWalletInfo()
+	go getChainTips()
 	log.Infoln("Listening on", *listenAddress)
 	if err := http.ListenAndServe(*listenAddress, nil); err != nil {
 		log.Fatal(err)
@@ -133,3 +134,30 @@ func getWalletInfo() {
 	}
 
 }
+
+func getChainTips() {
+	basicAuth := base64.StdEncoding.EncodeToString([]byte(*rpcUser + ":" + *rpcPassword))
+	rpcClient := jsonrpc.NewClientWithOpts("http://"+*rpcHost+":"+*rpcPort,
+		&jsonrpc.RPCClientOpts{
+			CustomHeaders: map[string]string{
+				"Authorization": "Basic " + basicAuth,
+			}})
+	var chaintips *GetChainTips
+
+	for {
+		if err := rpcClient.CallFor(&chaintips, "getchaintips"); err != nil {
+			log.Warnln("Error calling getchaintips", err)
+		} else {
+			for _, ct := range *chaintips {
+				log.Infoln("Got chaintip: ", ct.Height)
+				zcashdChainTips.WithLabelValues(
+					strconv.FormatFloat(ct.Height, 'f', 2, 64),
+					ct.Hash,
+					strconv.FormatFloat(ct.Branchlen, 'f', 2, 64),
+					ct.Status).Set(ct.Height)
+			}
+		}
+		time.Sleep(time.Duration(30) * time.Second)
+	}
+
+}
diff --git a/rpc.go b/rpc.go
index 4ea6496..e6d517a 100644
--- a/rpc.go
+++ b/rpc.go
@@ -25,3 +25,14 @@ type ZGetTotalBalance struct {
 	Private     string `json:"private"`
 	Total       string `json:"total"`
 }
+
+// GetChainTips Return information about all known tips in the block tree, including the main chain as well as orphaned branches.
+// https://zcash-rpc.github.io/getchaintips.html
+type GetChainTips []ChainTip
+
+type ChainTip struct {
+	Height    float64 `json:"height"`
+	Hash      string  `json:"hash"`
+	Branchlen float64 `json:"branchlen"`
+	Status    string  `json:"status"`
+}