From 88339c37597b748c69e137706a6f58231000578c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Thu, 11 Apr 2019 12:31:08 +0300
Subject: [PATCH] metrics/prometheus: minor typo cleanups, sorted report

---
 metrics/prometheus/collector.go  | 22 +++++++++++-----------
 metrics/prometheus/prometheus.go | 19 ++++++++++++++-----
 2 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/metrics/prometheus/collector.go b/metrics/prometheus/collector.go
index 73907e2e57..8350fa2aaf 100644
--- a/metrics/prometheus/collector.go
+++ b/metrics/prometheus/collector.go
@@ -26,11 +26,11 @@ import (
 )
 
 var (
-	typeGuageTpl           = "# TYPE %s gauge\n"
+	typeGaugeTpl           = "# TYPE %s gauge\n"
 	typeCounterTpl         = "# TYPE %s counter\n"
 	typeSummaryTpl         = "# TYPE %s summary\n"
-	keyValueTpl            = "%s %v\n"
-	keyQuantileTagValueTpl = "%s {quantile=\"%s\"} %v\n"
+	keyValueTpl            = "%s %v\n\n"
+	keyQuantileTagValueTpl = "%s {quantile=\"%s\"} %v\n\n"
 )
 
 // collector is a collection of byte buffers that aggregate Prometheus reports
@@ -47,15 +47,15 @@ func newCollector() *collector {
 }
 
 func (c *collector) addCounter(name string, m metrics.Counter) {
-	c.writeGuageCounter(name, m.Count())
+	c.writeGaugeCounter(name, m.Count())
 }
 
-func (c *collector) addGuage(name string, m metrics.Gauge) {
-	c.writeGuageCounter(name, m.Value())
+func (c *collector) addGauge(name string, m metrics.Gauge) {
+	c.writeGaugeCounter(name, m.Value())
 }
 
-func (c *collector) addGuageFloat64(name string, m metrics.GaugeFloat64) {
-	c.writeGuageCounter(name, m.Value())
+func (c *collector) addGaugeFloat64(name string, m metrics.GaugeFloat64) {
+	c.writeGaugeCounter(name, m.Value())
 }
 
 func (c *collector) addHistogram(name string, m metrics.Histogram) {
@@ -68,7 +68,7 @@ func (c *collector) addHistogram(name string, m metrics.Histogram) {
 }
 
 func (c *collector) addMeter(name string, m metrics.Meter) {
-	c.writeGuageCounter(name, m.Count())
+	c.writeGaugeCounter(name, m.Count())
 }
 
 func (c *collector) addTimer(name string, m metrics.Timer) {
@@ -92,9 +92,9 @@ func (c *collector) addResettingTimer(name string, m metrics.ResettingTimer) {
 	c.writeSummaryPercentile(name, "0.99", ps[2])
 }
 
-func (c *collector) writeGuageCounter(name string, value interface{}) {
+func (c *collector) writeGaugeCounter(name string, value interface{}) {
 	name = mutateKey(name)
-	c.buff.WriteString(fmt.Sprintf(typeGuageTpl, name))
+	c.buff.WriteString(fmt.Sprintf(typeGaugeTpl, name))
 	c.buff.WriteString(fmt.Sprintf(keyValueTpl, name, value))
 }
 
diff --git a/metrics/prometheus/prometheus.go b/metrics/prometheus/prometheus.go
index 0ee7511a18..9ad5ec7e99 100644
--- a/metrics/prometheus/prometheus.go
+++ b/metrics/prometheus/prometheus.go
@@ -20,6 +20,7 @@ package prometheus
 import (
 	"fmt"
 	"net/http"
+	"sort"
 
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/metrics"
@@ -28,17 +29,26 @@ import (
 // Handler returns an HTTP handler which dump metrics in Prometheus format.
 func Handler(reg metrics.Registry) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// Gather and pre-sort the metrics to avoid random listings
+		var names []string
+		reg.Each(func(name string, i interface{}) {
+			names = append(names, name)
+		})
+		sort.Strings(names)
+
 		// Aggregate all the metris into a Prometheus collector
 		c := newCollector()
 
-		reg.Each(func(name string, i interface{}) {
+		for _, name := range names {
+			i := reg.Get(name)
+
 			switch m := i.(type) {
 			case metrics.Counter:
 				c.addCounter(name, m.Snapshot())
 			case metrics.Gauge:
-				c.addGuage(name, m.Snapshot())
+				c.addGauge(name, m.Snapshot())
 			case metrics.GaugeFloat64:
-				c.addGuageFloat64(name, m.Snapshot())
+				c.addGaugeFloat64(name, m.Snapshot())
 			case metrics.Histogram:
 				c.addHistogram(name, m.Snapshot())
 			case metrics.Meter:
@@ -50,8 +60,7 @@ func Handler(reg metrics.Registry) http.Handler {
 			default:
 				log.Warn("Unknown Prometheus metric type", "type", fmt.Sprintf("%T", i))
 			}
-		})
-
+		}
 		w.Header().Add("Content-Type", "text/plain")
 		w.Header().Add("Content-Length", fmt.Sprint(c.buff.Len()))
 		w.Write(c.buff.Bytes())