[bugfix] Prometheus metrics without warnings

go-metrics is updated to 0.3.6 to properly handle help in prometheus metrics

This fixes https://github.com/hashicorp/consul/issues/9303 and
https://github.com/hashicorp/consul/issues/9471

.changelog/9510.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+client: Help added in Prometheus in relases 1.9.0 does not generate warnings anymore in logs
+```

go.mod

@@ -12,7 +12,7 @@ require (
 	github.com/Microsoft/go-winio v0.4.3 // indirect
 	github.com/NYTimes/gziphandler v1.0.1
 	github.com/armon/circbuf v0.0.0-20150827004946-bbbad097214e
-	github.com/armon/go-metrics v0.3.5-0.20201104215618-6fd5a4ddf425
+	github.com/armon/go-metrics v0.3.6
 	github.com/armon/go-radix v1.0.0
 	github.com/aws/aws-sdk-go v1.25.41
 	github.com/coredns/coredns v1.1.2

go.sum

@@ -59,8 +59,8 @@ github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5
 github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da/go.mod h1:Q73ZrmVTwzkszR9V5SSuryQ31EELlFMUz1kKyl939pY=
 github.com/armon/go-metrics v0.0.0-20190430140413-ec5e00d3c878/go.mod h1:3AMJUQhVx52RsWOnlkpikZr01T/yAVN2gn0861vByNg=
 github.com/armon/go-metrics v0.3.0/go.mod h1:zXjbSimjXTd7vOpY8B0/2LpvNvDoXBuplAD+gJD3GYs=
-github.com/armon/go-metrics v0.3.5-0.20201104215618-6fd5a4ddf425 h1:23nUvGE+8HYFc0AUXuYxgFws6IdyzOrSJJmKfPMJmi8=
+github.com/armon/go-metrics v0.3.6 h1:x/tmtOF9cDBoXH7XoAGOz2qqm1DknFD1590XmD/DUJ8=
-github.com/armon/go-metrics v0.3.5-0.20201104215618-6fd5a4ddf425/go.mod h1:4O98XIr/9W0sxpJ8UaYkvjk10Iff7SnFrb4QAOwNTFc=
+github.com/armon/go-metrics v0.3.6/go.mod h1:4O98XIr/9W0sxpJ8UaYkvjk10Iff7SnFrb4QAOwNTFc=
 github.com/armon/go-radix v0.0.0-20180808171621-7fddfc383310/go.mod h1:ufUuZ+zHj4x4TnLV4JWEpy2hxWSpsRywHrMgIH9cCH8=
 github.com/armon/go-radix v1.0.0 h1:F4z6KzEeeQIMeLFa97iZU6vupzoecKdU5TX24SNppXI=
 github.com/armon/go-radix v1.0.0/go.mod h1:ufUuZ+zHj4x4TnLV4JWEpy2hxWSpsRywHrMgIH9cCH8=

vendor/github.com/armon/go-metrics/metrics.go

@@ -228,12 +228,12 @@ func (m *Metrics) allowMetric(key []string, labels []Label) (bool, []Label) {
 func (m *Metrics) collectStats() {
 	for {
 		time.Sleep(m.ProfileInterval)
-		m.emitRuntimeStats()
+		m.EmitRuntimeStats()
 	}
 }
 
 // Emits various runtime statsitics
-func (m *Metrics) emitRuntimeStats() {
+func (m *Metrics) EmitRuntimeStats() {
 	// Export number of Goroutines
 	numRoutines := runtime.NumGoroutine()
 	m.SetGauge([]string{"runtime", "num_goroutines"}, float32(numRoutines))

vendor/github.com/armon/go-metrics/prometheus/prometheus.go

@@ -58,13 +58,14 @@ type PrometheusSink struct {
 	summaries  sync.Map
 	counters   sync.Map
 	expiration time.Duration
+	help       map[string]string
 }
 
 // GaugeDefinition can be provided to PrometheusOpts to declare a constant gauge that is not deleted on expiry.
 type GaugeDefinition struct {
-	Name []string
+	Name        []string
 	ConstLabels []metrics.Label
-	Help string
+	Help        string
 }
 
 type gauge struct {
@@ -76,9 +77,9 @@ type gauge struct {
 
 // SummaryDefinition can be provided to PrometheusOpts to declare a constant summary that is not deleted on expiry.
 type SummaryDefinition struct {
-	Name []string
+	Name        []string
 	ConstLabels []metrics.Label
-	Help string
+	Help        string
 }
 
 type summary struct {
@@ -89,9 +90,9 @@ type summary struct {
 
 // CounterDefinition can be provided to PrometheusOpts to declare a constant counter that is not deleted on expiry.
 type CounterDefinition struct {
-	Name []string
+	Name        []string
 	ConstLabels []metrics.Label
-	Help string
+	Help        string
 }
 
 type counter struct {
@@ -112,11 +113,12 @@ func NewPrometheusSinkFrom(opts PrometheusOpts) (*PrometheusSink, error) {
 		summaries:  sync.Map{},
 		counters:   sync.Map{},
 		expiration: opts.Expiration,
+		help:       make(map[string]string),
 	}
 
-	initGauges(&sink.gauges, opts.GaugeDefinitions)
+	initGauges(&sink.gauges, opts.GaugeDefinitions, sink.help)
-	initSummaries(&sink.summaries, opts.SummaryDefinitions)
+	initSummaries(&sink.summaries, opts.SummaryDefinitions, sink.help)
-	initCounters(&sink.counters, opts.CounterDefinitions)
+	initCounters(&sink.counters, opts.CounterDefinitions, sink.help)
 
 	reg := opts.Registerer
 	if reg == nil {
@@ -191,22 +193,24 @@ func (p *PrometheusSink) Collect(c chan<- prometheus.Metric) {
 	})
 }
 
-func initGauges(m *sync.Map, gauges []GaugeDefinition) {
+func initGauges(m *sync.Map, gauges []GaugeDefinition, help map[string]string) {
 	for _, g := range gauges {
 		key, hash := flattenKey(g.Name, g.ConstLabels)
+		help[fmt.Sprintf("gauge.%s", key)] = g.Help
 		pG := prometheus.NewGauge(prometheus.GaugeOpts{
 			Name:        key,
 			Help:        g.Help,
 			ConstLabels: prometheusLabels(g.ConstLabels),
 		})
-		m.Store(hash, &gauge{ Gauge: pG })
+		m.Store(hash, &gauge{Gauge: pG})
 	}
 	return
 }
 
-func initSummaries(m *sync.Map, summaries []SummaryDefinition) {
+func initSummaries(m *sync.Map, summaries []SummaryDefinition, help map[string]string) {
 	for _, s := range summaries {
 		key, hash := flattenKey(s.Name, s.ConstLabels)
+		help[fmt.Sprintf("summary.%s", key)] = s.Help
 		pS := prometheus.NewSummary(prometheus.SummaryOpts{
 			Name:        key,
 			Help:        s.Help,
@@ -214,20 +218,21 @@ func initSummaries(m *sync.Map, summaries []SummaryDefinition) {
 			ConstLabels: prometheusLabels(s.ConstLabels),
 			Objectives:  map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 		})
-		m.Store(hash, &summary{ Summary: pS })
+		m.Store(hash, &summary{Summary: pS})
 	}
 	return
 }
 
-func initCounters(m *sync.Map, counters []CounterDefinition) {
+func initCounters(m *sync.Map, counters []CounterDefinition, help map[string]string) {
 	for _, c := range counters {
 		key, hash := flattenKey(c.Name, c.ConstLabels)
+		help[fmt.Sprintf("counter.%s", key)] = c.Help
 		pC := prometheus.NewCounter(prometheus.CounterOpts{
 			Name:        key,
 			Help:        c.Help,
 			ConstLabels: prometheusLabels(c.ConstLabels),
 		})
-		m.Store(hash, &counter{ Counter: pC })
+		m.Store(hash, &counter{Counter: pC})
 	}
 	return
 }
@@ -274,16 +279,21 @@ func (p *PrometheusSink) SetGaugeWithLabels(parts []string, val float32, labels
 		localGauge.updatedAt = time.Now()
 		p.gauges.Store(hash, &localGauge)
 
-	// The gauge does not exist, create the gauge and allow it to be deleted
+		// The gauge does not exist, create the gauge and allow it to be deleted
 	} else {
+		help := key
+		existingHelp, ok := p.help[fmt.Sprintf("gauge.%s", key)]
+		if ok {
+			help = existingHelp
+		}
 		g := prometheus.NewGauge(prometheus.GaugeOpts{
 			Name:        key,
-			Help:        key,
+			Help:        help,
 			ConstLabels: prometheusLabels(labels),
 		})
 		g.Set(float64(val))
 		pg = &gauge{
-			Gauge: g,
+			Gauge:     g,
 			updatedAt: time.Now(),
 			canDelete: true,
 		}
@@ -306,18 +316,23 @@ func (p *PrometheusSink) AddSampleWithLabels(parts []string, val float32, labels
 		localSummary.updatedAt = time.Now()
 		p.summaries.Store(hash, &localSummary)
 
-	// The summary does not exist, create the Summary and allow it to be deleted
+		// The summary does not exist, create the Summary and allow it to be deleted
 	} else {
+		help := key
+		existingHelp, ok := p.help[fmt.Sprintf("summary.%s", key)]
+		if ok {
+			help = existingHelp
+		}
 		s := prometheus.NewSummary(prometheus.SummaryOpts{
 			Name:        key,
-			Help:        key,
+			Help:        help,
 			MaxAge:      10 * time.Second,
 			ConstLabels: prometheusLabels(labels),
 			Objectives:  map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
 		})
 		s.Observe(float64(val))
 		ps = &summary{
-			Summary: s,
+			Summary:   s,
 			updatedAt: time.Now(),
 			canDelete: true,
 		}
@@ -346,16 +361,21 @@ func (p *PrometheusSink) IncrCounterWithLabels(parts []string, val float32, labe
 		localCounter.updatedAt = time.Now()
 		p.counters.Store(hash, &localCounter)
 
-	// The counter does not exist yet, create it and allow it to be deleted
+		// The counter does not exist yet, create it and allow it to be deleted
 	} else {
+		help := key
+		existingHelp, ok := p.help[fmt.Sprintf("counter.%s", key)]
+		if ok {
+			help = existingHelp
+		}
 		c := prometheus.NewCounter(prometheus.CounterOpts{
 			Name:        key,
-			Help:        key,
+			Help:        help,
 			ConstLabels: prometheusLabels(labels),
 		})
 		c.Add(float64(val))
 		pc = &counter{
-			Counter: c,
+			Counter:   c,
 			updatedAt: time.Now(),
 			canDelete: true,
 		}

vendor/modules.txt

@@ -32,7 +32,7 @@ github.com/NYTimes/gziphandler
 github.com/StackExchange/wmi
 # github.com/armon/circbuf v0.0.0-20150827004946-bbbad097214e
 github.com/armon/circbuf
-# github.com/armon/go-metrics v0.3.5-0.20201104215618-6fd5a4ddf425
+# github.com/armon/go-metrics v0.3.6
 github.com/armon/go-metrics
 github.com/armon/go-metrics/circonus
 github.com/armon/go-metrics/datadog