From 1bdff076ad903c184c33bcdb70caf4b9f8c26c9c Mon Sep 17 00:00:00 2001
From: Anton Kaliaev <anton.kalyaev@gmail.com>
Date: Fri, 15 Jun 2018 17:21:04 +0400
Subject: [PATCH] add config option

---
 CHANGELOG.md     |  5 +++++
 config/config.go |  9 +++++++--
 config/toml.go   |  4 ++++
 node/node.go     | 25 +++++++++++++++++++++----
 4 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5afc0221..f69127d5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## TBD
+
+FEATURES:
+- [node] added metrics (served under /metrics using a Prometheus client; disabled by default)
+
 ## 0.20.1
 
 BUG FIXES:
diff --git a/config/config.go b/config/config.go
index 5ba568f2..c6cb6549 100644
--- a/config/config.go
+++ b/config/config.go
@@ -142,6 +142,10 @@ type BaseConfig struct {
 
 	// Database directory
 	DBPath string `mapstructure:"db_dir"`
+
+	// When true, metrics are served under `/metrics` using a Prometheus client
+	// Check out the documentation for the list of available metrics.
+	Monitoring bool `mapstructure:"monitoring"`
 }
 
 // DefaultBaseConfig returns a default base configuration for a Tendermint node
@@ -159,6 +163,7 @@ func DefaultBaseConfig() BaseConfig {
 		FilterPeers:       false,
 		DBBackend:         "leveldb",
 		DBPath:            "data",
+		Monitoring:        false,
 	}
 }
 
@@ -411,7 +416,7 @@ func (cfg *MempoolConfig) WalDir() string {
 //-----------------------------------------------------------------------------
 // ConsensusConfig
 
-// ConsensusConfig defines the confuguration for the Tendermint consensus service,
+// ConsensusConfig defines the configuration for the Tendermint consensus service,
 // including timeouts and details about the WAL and the block structure.
 type ConsensusConfig struct {
 	RootDir string `mapstructure:"home"`
@@ -536,7 +541,7 @@ func (cfg *ConsensusConfig) SetWalFile(walFile string) {
 //-----------------------------------------------------------------------------
 // TxIndexConfig
 
-// TxIndexConfig defines the confuguration for the transaction
+// TxIndexConfig defines the configuration for the transaction
 // indexer, including tags to index.
 type TxIndexConfig struct {
 	// What indexer to use for transactions
diff --git a/config/toml.go b/config/toml.go
index 7ed3e971..8927f15d 100644
--- a/config/toml.go
+++ b/config/toml.go
@@ -107,6 +107,10 @@ prof_laddr = "{{ .BaseConfig.ProfListenAddress }}"
 # so the app can decide if we should keep the connection or not
 filter_peers = {{ .BaseConfig.FilterPeers }}
 
+# When true, metrics are served under /metrics using a Prometheus client
+# Check out the documentation for the list of available metrics.
+monitoring = {{ .BaseConfig.Monitoring }}
+
 ##### advanced configuration options #####
 
 ##### rpc server configuration options #####
diff --git a/node/node.go b/node/node.go
index acb3461b..00d6cc40 100644
--- a/node/node.go
+++ b/node/node.go
@@ -93,8 +93,8 @@ func DefaultNewNode(config *cfg.Config, logger log.Logger) (*Node, error) {
 // MetricsProvider returns a consensus and p2p Metrics.
 type MetricsProvider func() (*cs.Metrics, *p2p.Metrics, *mempl.Metrics)
 
-// DefaultMetricsProvider returns a consensus and p2p Metrics build using
-// Prometheus client library.
+// DefaultMetricsProvider returns consensus, p2p and mempool Metrics build
+// using Prometheus client library.
 func DefaultMetricsProvider() (*cs.Metrics, *p2p.Metrics, *mempl.Metrics) {
 	return &cs.Metrics{
 			Height: prometheus.NewGaugeFrom(stdprometheus.GaugeOpts{
@@ -176,6 +176,11 @@ func DefaultMetricsProvider() (*cs.Metrics, *p2p.Metrics, *mempl.Metrics) {
 		}
 }
 
+// NopMetricsProvider returns consensus, p2p and mempool Metrics as no-op.
+func NopMetricsProvider() (*cs.Metrics, *p2p.Metrics, *mempl.Metrics) {
+	return cs.NopMetrics(), p2p.NopMetrics(), mempl.NopMetrics()
+}
+
 //------------------------------------------------------------------------------
 
 // Node is the highest level interface to a full Tendermint node.
@@ -300,7 +305,17 @@ func NewNode(config *cfg.Config,
 		consensusLogger.Info("This node is not a validator", "addr", privValidator.GetAddress(), "pubKey", privValidator.GetPubKey())
 	}
 
-	csMetrics, p2pMetrics, memplMetrics := metricsProvider()
+	// metrics
+	var (
+		csMetrics    *cs.Metrics
+		p2pMetrics   *p2p.Metrics
+		memplMetrics *mempl.Metrics
+	)
+	if config.BaseConfig.Monitoring {
+		csMetrics, p2pMetrics, memplMetrics = metricsProvider()
+	} else {
+		csMetrics, p2pMetrics, memplMetrics = NopMetricsProvider()
+	}
 
 	// Make MempoolReactor
 	mempoolLogger := logger.With("module", "mempool")
@@ -600,7 +615,9 @@ func (n *Node) startRPC() ([]net.Listener, error) {
 		wm := rpcserver.NewWebsocketManager(rpccore.Routes, coreCodec, rpcserver.EventSubscriber(n.eventBus))
 		wm.SetLogger(rpcLogger.With("protocol", "websocket"))
 		mux.HandleFunc("/websocket", wm.WebsocketHandler)
-		mux.Handle("/metrics", promhttp.Handler())
+		if n.config.BaseConfig.Monitoring {
+			mux.Handle("/metrics", promhttp.Handler())
+		}
 		rpcserver.RegisterRPCFuncs(mux, rpccore.Routes, coreCodec, rpcLogger)
 		listener, err := rpcserver.StartHTTPServer(listenAddr, mux, rpcLogger)
 		if err != nil {