From f36d4a3e733360de95cd29dd630390002752d506 Mon Sep 17 00:00:00 2001
From: "hazey.dazey" <hazey.dazey@hotmail.com>
Date: Sun, 23 Jul 2017 23:36:09 +0200
Subject: [PATCH] Add new default metric go_info

---
 prometheus/go_collector.go      | 10 +++++++++-
 prometheus/go_collector_test.go |  3 ++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/prometheus/go_collector.go b/prometheus/go_collector.go
index f967645..096454a 100644
--- a/prometheus/go_collector.go
+++ b/prometheus/go_collector.go
@@ -11,6 +11,7 @@ type goCollector struct {
 	goroutinesDesc *Desc
 	threadsDesc    *Desc
 	gcDesc         *Desc
+	goInfoDesc     *Desc
 
 	// metrics to describe and collect
 	metrics memStatsMetrics
@@ -26,12 +27,16 @@ func NewGoCollector() Collector {
 			nil, nil),
 		threadsDesc: NewDesc(
 			"go_threads",
-			"Number of OS threads created",
+			"Number of OS threads created.",
 			nil, nil),
 		gcDesc: NewDesc(
 			"go_gc_duration_seconds",
 			"A summary of the GC invocation durations.",
 			nil, nil),
+		goInfoDesc: NewDesc(
+			"go_info",
+			"Information about the Go environment.",
+			nil, Labels{"version": runtime.Version()}),
 		metrics: memStatsMetrics{
 			{
 				desc: NewDesc(
@@ -239,6 +244,7 @@ func (c *goCollector) Describe(ch chan<- *Desc) {
 	ch <- c.goroutinesDesc
 	ch <- c.threadsDesc
 	ch <- c.gcDesc
+	ch <- c.goInfoDesc
 	for _, i := range c.metrics {
 		ch <- i.desc
 	}
@@ -261,6 +267,8 @@ func (c *goCollector) Collect(ch chan<- Metric) {
 	quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
 	ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), float64(stats.PauseTotal.Seconds()), quantiles)
 
+	ch <- MustNewConstMetric(c.goInfoDesc, GaugeValue, 1)
+
 	ms := &runtime.MemStats{}
 	runtime.ReadMemStats(ms)
 	for _, i := range c.metrics {
diff --git a/prometheus/go_collector_test.go b/prometheus/go_collector_test.go
index 59dabc0..2d05118 100644
--- a/prometheus/go_collector_test.go
+++ b/prometheus/go_collector_test.go
@@ -54,10 +54,11 @@ func TestGoCollector(t *testing.T) {
 			}
 
 			// GoCollector performs three sends per call.
-			// On line 27 we need to receive the second send
+			// On line 27 we need to receive three more sends
 			// to shut down cleanly.
 			<-ch
 			<-ch
+			<-ch
 			return
 		case <-time.After(1 * time.Second):
 			t.Fatalf("expected collect timed out")