update vendor prometheus/client_golang to newest release

vendor/github.com/prometheus/client_golang/prometheus/desc.go

@@ -93,7 +93,7 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 	// First add only the const label names and sort them...
 	for labelName := range constLabels {
 		if !checkLabelName(labelName) {
-			d.err = fmt.Errorf("%q is not a valid label name", labelName)
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
 			return d
 		}
 		labelNames = append(labelNames, labelName)
@@ -115,7 +115,7 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 	// dimension with a different mix between preset and variable labels.
 	for _, labelName := range variableLabels {
 		if !checkLabelName(labelName) {
-			d.err = fmt.Errorf("%q is not a valid label name", labelName)
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
 			return d
 		}
 		labelNames = append(labelNames, "$"+labelName)

vendor/github.com/prometheus/client_golang/prometheus/registry.go

@@ -872,7 +872,13 @@ func checkMetricConsistency(
 	h = hashAddByte(h, separatorByte)
 	// Make sure label pairs are sorted. We depend on it for the consistency
 	// check.
-	sort.Sort(labelPairSorter(dtoMetric.Label))
+	if !sort.IsSorted(labelPairSorter(dtoMetric.Label)) {
+		// We cannot sort dtoMetric.Label in place as it is immutable by contract.
+		copiedLabels := make([]*dto.LabelPair, len(dtoMetric.Label))
+		copy(copiedLabels, dtoMetric.Label)
+		sort.Sort(labelPairSorter(copiedLabels))
+		dtoMetric.Label = copiedLabels
+	}
 	for _, lp := range dtoMetric.Label {
 		h = hashAdd(h, lp.GetName())
 		h = hashAddByte(h, separatorByte)
@@ -903,8 +909,8 @@ func checkDescConsistency(
 	}
 
 	// Is the desc consistent with the content of the metric?
-	lpsFromDesc := make([]*dto.LabelPair, 0, len(dtoMetric.Label))
-	lpsFromDesc = append(lpsFromDesc, desc.constLabelPairs...)
+	lpsFromDesc := make([]*dto.LabelPair, len(desc.constLabelPairs), len(dtoMetric.Label))
+	copy(lpsFromDesc, desc.constLabelPairs)
 	for _, l := range desc.variableLabels {
 		lpsFromDesc = append(lpsFromDesc, &dto.LabelPair{
 			Name: proto.String(l),

vendor/github.com/prometheus/client_golang/prometheus/testutil/testutil.go

@@ -37,7 +37,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"reflect"
 
 	"github.com/prometheus/common/expfmt"
 
@@ -125,38 +124,43 @@ func CollectAndCompare(c prometheus.Collector, expected io.Reader, metricNames .
 // exposition format. If any metricNames are provided, only metrics with those
 // names are compared.
 func GatherAndCompare(g prometheus.Gatherer, expected io.Reader, metricNames ...string) error {
-	metrics, err := g.Gather()
+	got, err := g.Gather()
 	if err != nil {
 		return fmt.Errorf("gathering metrics failed: %s", err)
 	}
 	if metricNames != nil {
-		metrics = filterMetrics(metrics, metricNames)
+		got = filterMetrics(got, metricNames)
 	}
 	var tp expfmt.TextParser
-	expectedMetrics, err := tp.TextToMetricFamilies(expected)
+	wantRaw, err := tp.TextToMetricFamilies(expected)
 	if err != nil {
 		return fmt.Errorf("parsing expected metrics failed: %s", err)
 	}
+	want := internal.NormalizeMetricFamilies(wantRaw)
 
-	if !reflect.DeepEqual(metrics, internal.NormalizeMetricFamilies(expectedMetrics)) {
-		// Encode the gathered output to the readable text format for comparison.
-		var buf1 bytes.Buffer
-		enc := expfmt.NewEncoder(&buf1, expfmt.FmtText)
-		for _, mf := range metrics {
-			if err := enc.Encode(mf); err != nil {
-				return fmt.Errorf("encoding result failed: %s", err)
-			}
-		}
-		// Encode normalized expected metrics again to generate them in the same ordering
-		// the registry does to spot differences more easily.
-		var buf2 bytes.Buffer
-		enc = expfmt.NewEncoder(&buf2, expfmt.FmtText)
-		for _, mf := range internal.NormalizeMetricFamilies(expectedMetrics) {
-			if err := enc.Encode(mf); err != nil {
-				return fmt.Errorf("encoding result failed: %s", err)
-			}
-		}
+	return compare(got, want)
+}
 
+// compare encodes both provided slices of metric families into the text format,
+// compares their string message, and returns an error if they do not match.
+// The error contains the encoded text of both the desired and the actual
+// result.
+func compare(got, want []*dto.MetricFamily) error {
+	var gotBuf, wantBuf bytes.Buffer
+	enc := expfmt.NewEncoder(&gotBuf, expfmt.FmtText)
+	for _, mf := range got {
+		if err := enc.Encode(mf); err != nil {
+			return fmt.Errorf("encoding gathered metrics failed: %s", err)
+		}
+	}
+	enc = expfmt.NewEncoder(&wantBuf, expfmt.FmtText)
+	for _, mf := range want {
+		if err := enc.Encode(mf); err != nil {
+			return fmt.Errorf("encoding expected metrics failed: %s", err)
+		}
+	}
+
+	if wantBuf.String() != gotBuf.String() {
 		return fmt.Errorf(`
 metric output does not match expectation; want:
 
@@ -165,7 +169,8 @@ metric output does not match expectation; want:
 got:
 
 %s
-`, buf2.String(), buf1.String())
+`, wantBuf.String(), gotBuf.String())
+
 	}
 	return nil
 }

vendor/github.com/prometheus/client_golang/prometheus/timer.go

@@ -39,13 +39,16 @@ func NewTimer(o Observer) *Timer {
 
 // ObserveDuration records the duration passed since the Timer was created with
 // NewTimer. It calls the Observe method of the Observer provided during
-// construction with the duration in seconds as an argument. ObserveDuration is
-// usually called with a defer statement.
+// construction with the duration in seconds as an argument. The observed
+// duration is also returned. ObserveDuration is usually called with a defer
+// statement.
 //
 // Note that this method is only guaranteed to never observe negative durations
 // if used with Go1.9+.
-func (t *Timer) ObserveDuration() {
+func (t *Timer) ObserveDuration() time.Duration {
+	d := time.Since(t.begin)
 	if t.observer != nil {
-		t.observer.Observe(time.Since(t.begin).Seconds())
+		t.observer.Observe(d.Seconds())
 	}
+	return d
 }