From eefee92f833791ae002afde89e1ee14de308a7d3 Mon Sep 17 00:00:00 2001
From: Andre Hahn <andre.hahn@tfgco.com>
Date: Thu, 19 Jul 2018 00:07:25 -0300
Subject: [PATCH] Making prometheus monitoring optional

---
 agent/agent.go                 |  2 +-
 app.go                         |  5 ++++-
 config/config.go               |  1 +
 metrics/constants.go           | 14 ++++++++++++++
 metrics/prometheus_reporter.go | 12 +-----------
 5 files changed, 21 insertions(+), 13 deletions(-)
 create mode 100644 metrics/constants.go

diff --git a/agent/agent.go b/agent/agent.go
index 6198b6b1..9f132373 100644
--- a/agent/agent.go
+++ b/agent/agent.go
@@ -121,7 +121,7 @@ func NewAgent(
 		metricsReporters:   metricsReporters,
 	}
 
-	// bindng session
+	// binding session
 	s := session.New(a, true)
 	metrics.ReportNumberOfConnectedClients(metricsReporters, session.SessionCount)
 	a.Session = s
diff --git a/app.go b/app.go
index e95d75e5..3ca01908 100644
--- a/app.go
+++ b/app.go
@@ -140,7 +140,10 @@ func Configure(
 	app.metricsReporters = make([]metrics.Reporter, 0)
 
 	defaultTags := app.config.GetStringMapString("pitaya.metrics.tags")
-	AddMetricsReporter(metrics.GetPrometheusReporter(serverType, app.config.GetString("pitaya.game"), app.config.GetInt("pitaya.metrics.prometheus.port"), defaultTags))
+	if app.config.GetBool("pitaya.metrics.prometheus.enabled") {
+		logger.Log.Infof("prometheus is enabled, configuring the metrics reporter on port %d", app.config.GetInt("pitaya.metrics.prometheus.port"))
+		AddMetricsReporter(metrics.GetPrometheusReporter(serverType, app.config.GetString("pitaya.game"), app.config.GetInt("pitaya.metrics.prometheus.port"), defaultTags))
+	}
 
 	if app.config.GetBool("pitaya.metrics.statsd.enabled") {
 		logger.Log.Infof("statsd is enabled, configuring the metrics reporter with host: %s", app.config.Get("pitaya.metrics.statsd.host"))
diff --git a/config/config.go b/config/config.go
index 2b6f948a..3e5a6d14 100644
--- a/config/config.go
+++ b/config/config.go
@@ -89,6 +89,7 @@ func (c *Config) fillDefaultValues() {
 		"pitaya.metrics.statsd.rate":                            1,
 		"pitaya.metrics.prometheus.port":                        9090,
 		"pitaya.metrics.tags":                                   map[string]string{},
+		"pitaya.metrics.prometheus.enabled":                     true,
 	}
 
 	for param := range defaultsMap {
diff --git a/metrics/constants.go b/metrics/constants.go
new file mode 100644
index 00000000..ca6cf536
--- /dev/null
+++ b/metrics/constants.go
@@ -0,0 +1,14 @@
+package metrics
+
+var (
+	// ResponseTime reports the response time of handlers and rpc
+	ResponseTime = "response_time_ns"
+	// ConnectedClients represents the number of current connected clients in frontend servers
+	ConnectedClients = "connected_clients"
+	// CountServers counts the number of servers of different types
+	CountServers = "count_servers"
+	// ChannelCapacity represents the capacity of a channel (available slots)
+	ChannelCapacity = "channel_capacity"
+	// DroppedMessages reports the number of dropped messages in rpc server (messages that will not be handled)
+	DroppedMessages = "dropped_messages"
+)
diff --git a/metrics/prometheus_reporter.go b/metrics/prometheus_reporter.go
index 7366e0a7..3519300e 100644
--- a/metrics/prometheus_reporter.go
+++ b/metrics/prometheus_reporter.go
@@ -31,16 +31,6 @@ import (
 )
 
 var (
-	// ResponseTime reports the response time of handlers and rpc
-	ResponseTime = "response_time_ns"
-	// ConnectedClients represents the number of current connected clients in frontend servers
-	ConnectedClients = "connected_clients"
-	// CountServers counts the number of servers of different types
-	CountServers = "count_servers"
-	// ChannelCapacity represents the capacity of a channel (available slots)
-	ChannelCapacity = "channel_capacity"
-	// DroppedMessages reports the number of dropped messages in rpc server (messages that will not be handled)
-	DroppedMessages    = "dropped_messages"
 	prometheusReporter *PrometheusReporter
 	once               sync.Once
 )
@@ -58,7 +48,7 @@ func (p *PrometheusReporter) registerMetrics(constLabels map[string]string) {
 	constLabels["game"] = p.game
 	constLabels["serverType"] = p.serverType
 
-	// HanadlerResponseTimeMs summaary
+	// HandlerResponseTimeMs summary
 	p.summaryReportersMap[ResponseTime] = prometheus.NewSummaryVec(
 		prometheus.SummaryOpts{
 			Namespace:   "pitaya",