vendor prometheus dependency.

github.com/prometheus/client_golang to v1.6.0
github.com/prometheus/client_model to v0.2.0
github.com/prometheus/common to v0.9.1
github.com/prometheus/procfs to v0.0.11

Signed-off-by: Jintao Zhang <zhangjintao9020@gmail.com>

vendor.conf

@@ -149,11 +149,11 @@ github.com/coreos/pkg                               3ac0863d7acf3bc44daf49afef89
 code.cloudfoundry.org/clock                         02e53af36e6c978af692887ed449b74026d76fec # v1.0.0
 
 # prometheus
-github.com/prometheus/client_golang                 c42bebe5a5cddfc6b28cd639103369d8a75dfa89 # v1.3.0
+github.com/prometheus/client_golang                 6edbbd9e560190e318cdc5b4d3e630b442858380 # v1.6.0
 github.com/beorn7/perks                             37c8de3658fcb183f997c4e13e8337516ab753e6 # v1.0.1
-github.com/prometheus/client_model                  d1d2010b5beead3fa1c5f271a5cf626e40b3ad6e # v0.1.0
-github.com/prometheus/common                        287d3e634a1e550c9e463dd7e5a75a422c614505 # v0.7.0
-github.com/prometheus/procfs                        6d489fc7f1d9cd890a250f3ea3431b1744b9623f # v0.0.8
+github.com/prometheus/client_model                  7bc5445566f0fe75b15de23e6b93886e982d7bf9 # v0.2.0
+github.com/prometheus/common                        d978bcb1309602d68bb4ba69cf3f8ed900e07308 # v0.9.1
+github.com/prometheus/procfs                        46159f73e74d1cb8dc223deef9b2d049286f46b1 # v0.0.11
 github.com/matttproud/golang_protobuf_extensions    c12348ce28de40eed0136aa2b644d0ee0650e56c # v1.0.1
 github.com/pkg/errors                               614d223910a179a466c1767a985424175c39b465 # v0.9.1
 github.com/grpc-ecosystem/go-grpc-prometheus        c225b8c3b01faf2899099b768856a9e916e5087b # v1.2.0

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

@@ -3,12 +3,16 @@ module github.com/prometheus/client_golang
 require (
 	github.com/beorn7/perks v1.0.1
 	github.com/cespare/xxhash/v2 v2.1.1
-	github.com/golang/protobuf v1.3.2
-	github.com/json-iterator/go v1.1.8
-	github.com/prometheus/client_model v0.1.0
-	github.com/prometheus/common v0.7.0
-	github.com/prometheus/procfs v0.0.8
-	golang.org/x/sys v0.0.0-20191220142924-d4481acd189f
+	github.com/golang/protobuf v1.4.0
+	github.com/json-iterator/go v1.1.9
+	github.com/kr/pretty v0.1.0 // indirect
+	github.com/prometheus/client_model v0.2.0
+	github.com/prometheus/common v0.9.1
+	github.com/prometheus/procfs v0.0.11
+	github.com/stretchr/testify v1.4.0 // indirect
+	golang.org/x/sys v0.0.0-20200420163511-1957bb5e6d1f
+	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
+	gopkg.in/yaml.v2 v2.2.5 // indirect
 )
 
 go 1.11

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

@@ -17,6 +17,7 @@ import (
 	"errors"
 	"math"
 	"sync/atomic"
+	"time"
 
 	dto "github.com/prometheus/client_model/go"
 )
@@ -42,11 +43,27 @@ type Counter interface {
 	Add(float64)
 }
 
+// ExemplarAdder is implemented by Counters that offer the option of adding a
+// value to the Counter together with an exemplar. Its AddWithExemplar method
+// works like the Add method of the Counter interface but also replaces the
+// currently saved exemplar (if any) with a new one, created from the provided
+// value, the current time as timestamp, and the provided labels. Empty Labels
+// will lead to a valid (label-less) exemplar. But if Labels is nil, the current
+// exemplar is left in place. AddWithExemplar panics if the value is < 0, if any
+// of the provided labels are invalid, or if the provided labels contain more
+// than 64 runes in total.
+type ExemplarAdder interface {
+	AddWithExemplar(value float64, exemplar Labels)
+}
+
 // CounterOpts is an alias for Opts. See there for doc comments.
 type CounterOpts Opts
 
 // NewCounter creates a new Counter based on the provided CounterOpts.
 //
+// The returned implementation also implements ExemplarAdder. It is safe to
+// perform the corresponding type assertion.
+//
 // The returned implementation tracks the counter value in two separate
 // variables, a float64 and a uint64. The latter is used to track calls of the
 // Inc method and calls of the Add method with a value that can be represented
@@ -61,7 +78,7 @@ func NewCounter(opts CounterOpts) Counter {
 		nil,
 		opts.ConstLabels,
 	)
-	result := &counter{desc: desc, labelPairs: desc.constLabelPairs}
+	result := &counter{desc: desc, labelPairs: desc.constLabelPairs, now: time.Now}
 	result.init(result) // Init self-collection.
 	return result
 }
@@ -78,6 +95,9 @@ type counter struct {
 	desc *Desc
 
 	labelPairs []*dto.LabelPair
+	exemplar   atomic.Value // Containing nil or a *dto.Exemplar.
+
+	now func() time.Time // To mock out time.Now() for testing.
 }
 
 func (c *counter) Desc() *Desc {
@@ -88,6 +108,7 @@ func (c *counter) Add(v float64) {
 	if v < 0 {
 		panic(errors.New("counter cannot decrease in value"))
 	}
+
 	ival := uint64(v)
 	if float64(ival) == v {
 		atomic.AddUint64(&c.valInt, ival)
@@ -103,6 +124,11 @@ func (c *counter) Add(v float64) {
 	}
 }
 
+func (c *counter) AddWithExemplar(v float64, e Labels) {
+	c.Add(v)
+	c.updateExemplar(v, e)
+}
+
 func (c *counter) Inc() {
 	atomic.AddUint64(&c.valInt, 1)
 }
@@ -112,7 +138,23 @@ func (c *counter) Write(out *dto.Metric) error {
 	ival := atomic.LoadUint64(&c.valInt)
 	val := fval + float64(ival)
 
-	return populateMetric(CounterValue, val, c.labelPairs, out)
+	var exemplar *dto.Exemplar
+	if e := c.exemplar.Load(); e != nil {
+		exemplar = e.(*dto.Exemplar)
+	}
+
+	return populateMetric(CounterValue, val, c.labelPairs, exemplar, out)
+}
+
+func (c *counter) updateExemplar(v float64, l Labels) {
+	if l == nil {
+		return
+	}
+	e, err := newExemplar(v, c.now(), l)
+	if err != nil {
+		panic(err)
+	}
+	c.exemplar.Store(e)
 }
 
 // CounterVec is a Collector that bundles a set of Counters that all share the
@@ -138,7 +180,7 @@ func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
 			if len(lvs) != len(desc.variableLabels) {
 				panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, lvs))
 			}
-			result := &counter{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
+			result := &counter{desc: desc, labelPairs: makeLabelPairs(desc, lvs), now: time.Now}
 			result.init(result) // Init self-collection.
 			return result
 		}),
@@ -267,6 +309,8 @@ type CounterFunc interface {
 // provided function must be concurrency-safe. The function should also honor
 // the contract for a Counter (values only go up, not down), but compliance will
 // not be checked.
+//
+// Check out the ExampleGaugeFunc examples for the similar GaugeFunc.
 func NewCounterFunc(opts CounterOpts, function func() float64) CounterFunc {
 	return newValueFunc(NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),

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

@@ -84,25 +84,21 @@
 // of those four metric types can be found in the Prometheus docs:
 // https://prometheus.io/docs/concepts/metric_types/
 //
-// A fifth "type" of metric is Untyped. It behaves like a Gauge, but signals the
-// Prometheus server not to assume anything about its type.
-//
-// In addition to the fundamental metric types Gauge, Counter, Summary,
-// Histogram, and Untyped, a very important part of the Prometheus data model is
-// the partitioning of samples along dimensions called labels, which results in
+// In addition to the fundamental metric types Gauge, Counter, Summary, and
+// Histogram, a very important part of the Prometheus data model is the
+// partitioning of samples along dimensions called labels, which results in
 // metric vectors. The fundamental types are GaugeVec, CounterVec, SummaryVec,
-// HistogramVec, and UntypedVec.
+// and HistogramVec.
 //
 // While only the fundamental metric types implement the Metric interface, both
 // the metrics and their vector versions implement the Collector interface. A
 // Collector manages the collection of a number of Metrics, but for convenience,
-// a Metric can also “collect itself”. Note that Gauge, Counter, Summary,
-// Histogram, and Untyped are interfaces themselves while GaugeVec, CounterVec,
-// SummaryVec, HistogramVec, and UntypedVec are not.
+// a Metric can also “collect itself”. Note that Gauge, Counter, Summary, and
+// Histogram are interfaces themselves while GaugeVec, CounterVec, SummaryVec,
+// and HistogramVec are not.
 //
 // To create instances of Metrics and their vector versions, you need a suitable
-// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts, HistogramOpts, or
-// UntypedOpts.
+// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts, or HistogramOpts.
 //
 // Custom Collectors and constant Metrics
 //
@@ -118,13 +114,16 @@
 // existing numbers into Prometheus Metrics during collection. An own
 // implementation of the Collector interface is perfect for that. You can create
 // Metric instances “on the fly” using NewConstMetric, NewConstHistogram, and
-// NewConstSummary (and their respective Must… versions). That will happen in
-// the Collect method. The Describe method has to return separate Desc
-// instances, representative of the “throw-away” metrics to be created later.
-// NewDesc comes in handy to create those Desc instances. Alternatively, you
-// could return no Desc at all, which will mark the Collector “unchecked”.  No
-// checks are performed at registration time, but metric consistency will still
-// be ensured at scrape time, i.e. any inconsistencies will lead to scrape
+// NewConstSummary (and their respective Must… versions). NewConstMetric is used
+// for all metric types with just a float64 as their value: Counter, Gauge, and
+// a special “type” called Untyped. Use the latter if you are not sure if the
+// mirrored metric is a Counter or a Gauge. Creation of the Metric instance
+// happens in the Collect method. The Describe method has to return separate
+// Desc instances, representative of the “throw-away” metrics to be created
+// later.  NewDesc comes in handy to create those Desc instances. Alternatively,
+// you could return no Desc at all, which will mark the Collector “unchecked”.
+// No checks are performed at registration time, but metric consistency will
+// still be ensured at scrape time, i.e. any inconsistencies will lead to scrape
 // errors. Thus, with unchecked Collectors, the responsibility to not collect
 // metrics that lead to inconsistencies in the total scrape result lies with the
 // implementer of the Collector. While this is not a desirable state, it is

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

@@ -123,7 +123,7 @@ func (g *gauge) Sub(val float64) {
 
 func (g *gauge) Write(out *dto.Metric) error {
 	val := math.Float64frombits(atomic.LoadUint64(&g.valBits))
-	return populateMetric(GaugeValue, val, g.labelPairs, out)
+	return populateMetric(GaugeValue, val, g.labelPairs, nil, out)
 }
 
 // GaugeVec is a Collector that bundles a set of Gauges that all share the same

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

@@ -73,7 +73,7 @@ func NewGoCollector() Collector {
 			nil, nil),
 		gcDesc: NewDesc(
 			"go_gc_duration_seconds",
-			"A summary of the GC invocation durations.",
+			"A summary of the pause duration of garbage collection cycles.",
 			nil, nil),
 		goInfoDesc: NewDesc(
 			"go_info",

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

@@ -20,6 +20,7 @@ import (
 	"sort"
 	"sync"
 	"sync/atomic"
+	"time"
 
 	"github.com/golang/protobuf/proto"
 
@@ -151,6 +152,10 @@ type HistogramOpts struct {
 
 // NewHistogram creates a new Histogram based on the provided HistogramOpts. It
 // panics if the buckets in HistogramOpts are not in strictly increasing order.
+//
+// The returned implementation also implements ExemplarObserver. It is safe to
+// perform the corresponding type assertion. Exemplars are tracked separately
+// for each bucket.
 func NewHistogram(opts HistogramOpts) Histogram {
 	return newHistogram(
 		NewDesc(
@@ -188,6 +193,7 @@ func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogr
 		upperBounds: opts.Buckets,
 		labelPairs:  makeLabelPairs(desc, labelValues),
 		counts:      [2]*histogramCounts{{}, {}},
+		now:         time.Now,
 	}
 	for i, upperBound := range h.upperBounds {
 		if i < len(h.upperBounds)-1 {
@@ -205,9 +211,10 @@ func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogr
 		}
 	}
 	// Finally we know the final length of h.upperBounds and can make buckets
-	// for both counts:
+	// for both counts as well as exemplars:
 	h.counts[0].buckets = make([]uint64, len(h.upperBounds))
 	h.counts[1].buckets = make([]uint64, len(h.upperBounds))
+	h.exemplars = make([]atomic.Value, len(h.upperBounds)+1)
 
 	h.init(h) // Init self-collection.
 	return h
@@ -254,6 +261,9 @@ type histogram struct {
 
 	upperBounds []float64
 	labelPairs  []*dto.LabelPair
+	exemplars   []atomic.Value // One more than buckets (to include +Inf), each a *dto.Exemplar.
+
+	now func() time.Time // To mock out time.Now() for testing.
 }
 
 func (h *histogram) Desc() *Desc {
@@ -261,36 +271,13 @@ func (h *histogram) Desc() *Desc {
 }
 
 func (h *histogram) Observe(v float64) {
-	// TODO(beorn7): For small numbers of buckets (<30), a linear search is
-	// slightly faster than the binary search. If we really care, we could
-	// switch from one search strategy to the other depending on the number
-	// of buckets.
-	//
-	// Microbenchmarks (BenchmarkHistogramNoLabels):
-	// 11 buckets: 38.3 ns/op linear - binary 48.7 ns/op
-	// 100 buckets: 78.1 ns/op linear - binary 54.9 ns/op
-	// 300 buckets: 154 ns/op linear - binary 61.6 ns/op
-	i := sort.SearchFloat64s(h.upperBounds, v)
-
-	// We increment h.countAndHotIdx so that the counter in the lower
-	// 63 bits gets incremented. At the same time, we get the new value
-	// back, which we can use to find the currently-hot counts.
-	n := atomic.AddUint64(&h.countAndHotIdx, 1)
-	hotCounts := h.counts[n>>63]
+	h.observe(v, h.findBucket(v))
+}
 
-	if i < len(h.upperBounds) {
-		atomic.AddUint64(&hotCounts.buckets[i], 1)
-	}
-	for {
-		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
-		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
-		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
-			break
-		}
-	}
-	// Increment count last as we take it as a signal that the observation
-	// is complete.
-	atomic.AddUint64(&hotCounts.count, 1)
+func (h *histogram) ObserveWithExemplar(v float64, e Labels) {
+	i := h.findBucket(v)
+	h.observe(v, i)
+	h.updateExemplar(v, i, e)
 }
 
 func (h *histogram) Write(out *dto.Metric) error {
@@ -329,6 +316,18 @@ func (h *histogram) Write(out *dto.Metric) error {
 			CumulativeCount: proto.Uint64(cumCount),
 			UpperBound:      proto.Float64(upperBound),
 		}
+		if e := h.exemplars[i].Load(); e != nil {
+			his.Bucket[i].Exemplar = e.(*dto.Exemplar)
+		}
+	}
+	// If there is an exemplar for the +Inf bucket, we have to add that bucket explicitly.
+	if e := h.exemplars[len(h.upperBounds)].Load(); e != nil {
+		b := &dto.Bucket{
+			CumulativeCount: proto.Uint64(count),
+			UpperBound:      proto.Float64(math.Inf(1)),
+			Exemplar:        e.(*dto.Exemplar),
+		}
+		his.Bucket = append(his.Bucket, b)
 	}
 
 	out.Histogram = his
@@ -352,6 +351,57 @@ func (h *histogram) Write(out *dto.Metric) error {
 	return nil
 }
 
+// findBucket returns the index of the bucket for the provided value, or
+// len(h.upperBounds) for the +Inf bucket.
+func (h *histogram) findBucket(v float64) int {
+	// TODO(beorn7): For small numbers of buckets (<30), a linear search is
+	// slightly faster than the binary search. If we really care, we could
+	// switch from one search strategy to the other depending on the number
+	// of buckets.
+	//
+	// Microbenchmarks (BenchmarkHistogramNoLabels):
+	// 11 buckets: 38.3 ns/op linear - binary 48.7 ns/op
+	// 100 buckets: 78.1 ns/op linear - binary 54.9 ns/op
+	// 300 buckets: 154 ns/op linear - binary 61.6 ns/op
+	return sort.SearchFloat64s(h.upperBounds, v)
+}
+
+// observe is the implementation for Observe without the findBucket part.
+func (h *histogram) observe(v float64, bucket int) {
+	// We increment h.countAndHotIdx so that the counter in the lower
+	// 63 bits gets incremented. At the same time, we get the new value
+	// back, which we can use to find the currently-hot counts.
+	n := atomic.AddUint64(&h.countAndHotIdx, 1)
+	hotCounts := h.counts[n>>63]
+
+	if bucket < len(h.upperBounds) {
+		atomic.AddUint64(&hotCounts.buckets[bucket], 1)
+	}
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			break
+		}
+	}
+	// Increment count last as we take it as a signal that the observation
+	// is complete.
+	atomic.AddUint64(&hotCounts.count, 1)
+}
+
+// updateExemplar replaces the exemplar for the provided bucket. With empty
+// labels, it's a no-op. It panics if any of the labels is invalid.
+func (h *histogram) updateExemplar(v float64, bucket int, l Labels) {
+	if l == nil {
+		return
+	}
+	e, err := newExemplar(v, h.now(), l)
+	if err != nil {
+		panic(err)
+	}
+	h.exemplars[bucket].Store(e)
+}
+
 // HistogramVec is a Collector that bundles a set of Histograms that all share the
 // same Desc, but have different values for their variable labels. This is used
 // if you want to count the same thing partitioned by various dimensions

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

@@ -50,3 +50,15 @@ type ObserverVec interface {
 
 	Collector
 }
+
+// ExemplarObserver is implemented by Observers that offer the option of
+// observing a value together with an exemplar. Its ObserveWithExemplar method
+// works like the Observe method of an Observer but also replaces the currently
+// saved exemplar (if any) with a new one, created from the provided value, the
+// current time as timestamp, and the provided Labels. Empty Labels will lead to
+// a valid (label-less) exemplar. But if Labels is nil, the current exemplar is
+// left in place. ObserveWithExemplar panics if any of the provided labels are
+// invalid or if the provided labels contain more than 64 runes in total.
+type ExemplarObserver interface {
+	ObserveWithExemplar(value float64, exemplar Labels)
+}

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

@@ -33,18 +33,22 @@ var (
 )
 
 type processMemoryCounters struct {
-	// https://docs.microsoft.com/en-us/windows/desktop/api/psapi/ns-psapi-_process_memory_counters_ex
+	// System interface description
+	// https://docs.microsoft.com/en-us/windows/desktop/api/psapi/ns-psapi-process_memory_counters_ex
+
+	// Refer to the Golang internal implementation
+	// https://golang.org/src/internal/syscall/windows/psapi_windows.go
 	_                          uint32
 	PageFaultCount             uint32
-	PeakWorkingSetSize         uint64
-	WorkingSetSize             uint64
-	QuotaPeakPagedPoolUsage    uint64
-	QuotaPagedPoolUsage        uint64
-	QuotaPeakNonPagedPoolUsage uint64
-	QuotaNonPagedPoolUsage     uint64
-	PagefileUsage              uint64
-	PeakPagefileUsage          uint64
-	PrivateUsage               uint64
+	PeakWorkingSetSize         uintptr
+	WorkingSetSize             uintptr
+	QuotaPeakPagedPoolUsage    uintptr
+	QuotaPagedPoolUsage        uintptr
+	QuotaPeakNonPagedPoolUsage uintptr
+	QuotaNonPagedPoolUsage     uintptr
+	PagefileUsage              uintptr
+	PeakPagefileUsage          uintptr
+	PrivateUsage               uintptr
 }
 
 func getProcessMemoryInfo(handle windows.Handle) (processMemoryCounters, error) {

vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go

@@ -53,12 +53,16 @@ func (r *responseWriterDelegator) Written() int64 {
 }
 
 func (r *responseWriterDelegator) WriteHeader(code int) {
+	if r.observeWriteHeader != nil && !r.wroteHeader {
+		// Only call observeWriteHeader for the 1st time. It's a bug if
+		// WriteHeader is called more than once, but we want to protect
+		// against it here. Note that we still delegate the WriteHeader
+		// to the original ResponseWriter to not mask the bug from it.
+		r.observeWriteHeader(code)
+	}
 	r.status = code
 	r.wroteHeader = true
 	r.ResponseWriter.WriteHeader(code)
-	if r.observeWriteHeader != nil {
-		r.observeWriteHeader(code)
-	}
 }
 
 func (r *responseWriterDelegator) Write(b []byte) (int, error) {

vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go

@@ -144,7 +144,12 @@ func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
 			}
 		}
 
-		contentType := expfmt.Negotiate(req.Header)
+		var contentType expfmt.Format
+		if opts.EnableOpenMetrics {
+			contentType = expfmt.NegotiateIncludingOpenMetrics(req.Header)
+		} else {
+			contentType = expfmt.Negotiate(req.Header)
+		}
 		header := rsp.Header()
 		header.Set(contentTypeHeader, string(contentType))
 
@@ -162,28 +167,40 @@ func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
 
 		enc := expfmt.NewEncoder(w, contentType)
 
-		var lastErr error
-		for _, mf := range mfs {
-			if err := enc.Encode(mf); err != nil {
-				lastErr = err
-				if opts.ErrorLog != nil {
-					opts.ErrorLog.Println("error encoding and sending metric family:", err)
-				}
-				errCnt.WithLabelValues("encoding").Inc()
-				switch opts.ErrorHandling {
-				case PanicOnError:
-					panic(err)
-				case ContinueOnError:
-					// Handled later.
-				case HTTPErrorOnError:
-					httpError(rsp, err)
-					return
-				}
+		// handleError handles the error according to opts.ErrorHandling
+		// and returns true if we have to abort after the handling.
+		handleError := func(err error) bool {
+			if err == nil {
+				return false
+			}
+			if opts.ErrorLog != nil {
+				opts.ErrorLog.Println("error encoding and sending metric family:", err)
+			}
+			errCnt.WithLabelValues("encoding").Inc()
+			switch opts.ErrorHandling {
+			case PanicOnError:
+				panic(err)
+			case HTTPErrorOnError:
+				// We cannot really send an HTTP error at this
+				// point because we most likely have written
+				// something to rsp already. But at least we can
+				// stop sending.
+				return true
 			}
+			// Do nothing in all other cases, including ContinueOnError.
+			return false
 		}
 
-		if lastErr != nil {
-			httpError(rsp, lastErr)
+		for _, mf := range mfs {
+			if handleError(enc.Encode(mf)) {
+				return
+			}
+		}
+		if closer, ok := enc.(expfmt.Closer); ok {
+			// This in particular takes care of the final "# EOF\n" line for OpenMetrics.
+			if handleError(closer.Close()) {
+				return
+			}
 		}
 	})
 
@@ -255,7 +272,12 @@ type HandlerErrorHandling int
 // errors are encountered.
 const (
 	// Serve an HTTP status code 500 upon the first error
-	// encountered. Report the error message in the body.
+	// encountered. Report the error message in the body. Note that HTTP
+	// errors cannot be served anymore once the beginning of a regular
+	// payload has been sent. Thus, in the (unlikely) case that encoding the
+	// payload into the negotiated wire format fails, serving the response
+	// will simply be aborted. Set an ErrorLog in HandlerOpts to detect
+	// those errors.
 	HTTPErrorOnError HandlerErrorHandling = iota
 	// Ignore errors and try to serve as many metrics as possible.  However,
 	// if no metrics can be served, serve an HTTP status code 500 and the
@@ -318,6 +340,16 @@ type HandlerOpts struct {
 	// away). Until the implementation is improved, it is recommended to
 	// implement a separate timeout in potentially slow Collectors.
 	Timeout time.Duration
+	// If true, the experimental OpenMetrics encoding is added to the
+	// possible options during content negotiation. Note that Prometheus
+	// 2.5.0+ will negotiate OpenMetrics as first priority. OpenMetrics is
+	// the only way to transmit exemplars. However, the move to OpenMetrics
+	// is not completely transparent. Most notably, the values of "quantile"
+	// labels of Summaries and "le" labels of Histograms are formatted with
+	// a trailing ".0" if they would otherwise look like integer numbers
+	// (which changes the identity of the resulting series on the Prometheus
+	// server).
+	EnableOpenMetrics bool
 }
 
 // gzipAccepted returns whether the client will accept gzip-encoded content.
@@ -334,11 +366,9 @@ func gzipAccepted(header http.Header) bool {
 }
 
 // httpError removes any content-encoding header and then calls http.Error with
-// the provided error and http.StatusInternalServerErrer. Error contents is
-// supposed to be uncompressed plain text. However, same as with a plain
-// http.Error, any header settings will be void if the header has already been
-// sent. The error message will still be written to the writer, but it will
-// probably be of limited use.
+// the provided error and http.StatusInternalServerError. Error contents is
+// supposed to be uncompressed plain text. Same as with a plain http.Error, this
+// must not be called if the header or any payload has already been sent.
 func httpError(rsp http.ResponseWriter, err error) {
 	rsp.Header().Del(contentEncodingHeader)
 	http.Error(

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

@@ -16,8 +16,11 @@ package prometheus
 import (
 	"fmt"
 	"sort"
+	"time"
+	"unicode/utf8"
 
 	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes"
 
 	dto "github.com/prometheus/client_model/go"
 )
@@ -25,7 +28,8 @@ import (
 // ValueType is an enumeration of metric types that represent a simple value.
 type ValueType int
 
-// Possible values for the ValueType enum.
+// Possible values for the ValueType enum. Use UntypedValue to mark a metric
+// with an unknown type.
 const (
 	_ ValueType = iota
 	CounterValue
@@ -69,7 +73,7 @@ func (v *valueFunc) Desc() *Desc {
 }
 
 func (v *valueFunc) Write(out *dto.Metric) error {
-	return populateMetric(v.valType, v.function(), v.labelPairs, out)
+	return populateMetric(v.valType, v.function(), v.labelPairs, nil, out)
 }
 
 // NewConstMetric returns a metric with one fixed value that cannot be
@@ -116,19 +120,20 @@ func (m *constMetric) Desc() *Desc {
 }
 
 func (m *constMetric) Write(out *dto.Metric) error {
-	return populateMetric(m.valType, m.val, m.labelPairs, out)
+	return populateMetric(m.valType, m.val, m.labelPairs, nil, out)
 }
 
 func populateMetric(
 	t ValueType,
 	v float64,
 	labelPairs []*dto.LabelPair,
+	e *dto.Exemplar,
 	m *dto.Metric,
 ) error {
 	m.Label = labelPairs
 	switch t {
 	case CounterValue:
-		m.Counter = &dto.Counter{Value: proto.Float64(v)}
+		m.Counter = &dto.Counter{Value: proto.Float64(v), Exemplar: e}
 	case GaugeValue:
 		m.Gauge = &dto.Gauge{Value: proto.Float64(v)}
 	case UntypedValue:
@@ -160,3 +165,40 @@ func makeLabelPairs(desc *Desc, labelValues []string) []*dto.LabelPair {
 	sort.Sort(labelPairSorter(labelPairs))
 	return labelPairs
 }
+
+// ExemplarMaxRunes is the max total number of runes allowed in exemplar labels.
+const ExemplarMaxRunes = 64
+
+// newExemplar creates a new dto.Exemplar from the provided values. An error is
+// returned if any of the label names or values are invalid or if the total
+// number of runes in the label names and values exceeds ExemplarMaxRunes.
+func newExemplar(value float64, ts time.Time, l Labels) (*dto.Exemplar, error) {
+	e := &dto.Exemplar{}
+	e.Value = proto.Float64(value)
+	tsProto, err := ptypes.TimestampProto(ts)
+	if err != nil {
+		return nil, err
+	}
+	e.Timestamp = tsProto
+	labelPairs := make([]*dto.LabelPair, 0, len(l))
+	var runes int
+	for name, value := range l {
+		if !checkLabelName(name) {
+			return nil, fmt.Errorf("exemplar label name %q is invalid", name)
+		}
+		runes += utf8.RuneCountInString(name)
+		if !utf8.ValidString(value) {
+			return nil, fmt.Errorf("exemplar label value %q is not valid UTF-8", value)
+		}
+		runes += utf8.RuneCountInString(value)
+		labelPairs = append(labelPairs, &dto.LabelPair{
+			Name:  proto.String(name),
+			Value: proto.String(value),
+		})
+	}
+	if runes > ExemplarMaxRunes {
+		return nil, fmt.Errorf("exemplar labels have %d runes, exceeding the limit of %d", runes, ExemplarMaxRunes)
+	}
+	e.Label = labelPairs
+	return e, nil
+}

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

@@ -91,6 +91,18 @@ func (m *metricVec) Delete(labels Labels) bool {
 	return m.metricMap.deleteByHashWithLabels(h, labels, m.curry)
 }
 
+// Without explicit forwarding of Describe, Collect, Reset, those methods won't
+// show up in GoDoc.
+
+// Describe implements Collector.
+func (m *metricVec) Describe(ch chan<- *Desc) { m.metricMap.Describe(ch) }
+
+// Collect implements Collector.
+func (m *metricVec) Collect(ch chan<- Metric) { m.metricMap.Collect(ch) }
+
+// Reset deletes all metrics in this vector.
+func (m *metricVec) Reset() { m.metricMap.Reset() }
+
 func (m *metricVec) curryWith(labels Labels) (*metricVec, error) {
 	var (
 		newCurry []curriedLabelValue

vendor/github.com/prometheus/client_model/go/metrics.pb.go

@@ -1,11 +1,14 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // source: metrics.proto
 
-package io_prometheus_client // import "github.com/prometheus/client_model/go"
+package io_prometheus_client
 
-import proto "github.com/golang/protobuf/proto"
-import fmt "fmt"
-import math "math"
+import (
+	fmt "fmt"
+	proto "github.com/golang/protobuf/proto"
+	timestamp "github.com/golang/protobuf/ptypes/timestamp"
+	math "math"
+)
 
 // Reference imports to suppress errors if they are not otherwise used.
 var _ = proto.Marshal
@@ -16,7 +19,7 @@ var _ = math.Inf
 // is compatible with the proto package it is being compiled against.
 // A compilation error at this line likely means your copy of the
 // proto package needs to be updated.
-const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
+const _ = proto.ProtoPackageIsVersion3 // please upgrade the proto package
 
 type MetricType int32
 
@@ -35,6 +38,7 @@ var MetricType_name = map[int32]string{
 	3: "UNTYPED",
 	4: "HISTOGRAM",
 }
+
 var MetricType_value = map[string]int32{
 	"COUNTER":   0,
 	"GAUGE":     1,
@@ -48,9 +52,11 @@ func (x MetricType) Enum() *MetricType {
 	*p = x
 	return p
 }
+
 func (x MetricType) String() string {
 	return proto.EnumName(MetricType_name, int32(x))
 }
+
 func (x *MetricType) UnmarshalJSON(data []byte) error {
 	value, err := proto.UnmarshalJSONEnum(MetricType_value, data, "MetricType")
 	if err != nil {
@@ -59,8 +65,9 @@ func (x *MetricType) UnmarshalJSON(data []byte) error {
 	*x = MetricType(value)
 	return nil
 }
+
 func (MetricType) EnumDescriptor() ([]byte, []int) {
-	return fileDescriptor_metrics_c97c9a2b9560cb8f, []int{0}
+	return fileDescriptor_6039342a2ba47b72, []int{0}
 }
 
 type LabelPair struct {
@@ -75,16 +82,17 @@ func (m *LabelPair) Reset()         { *m = LabelPair{} }
 func (m *LabelPair) String() string { return proto.CompactTextString(m) }
 func (*LabelPair) ProtoMessage()    {}
 func (*LabelPair) Descriptor() ([]byte, []int) {
-	return fileDescriptor_metrics_c97c9a2b9560cb8f, []int{0}
+	return fileDescriptor_6039342a2ba47b72, []int{0}
 }
+
 func (m *LabelPair) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_LabelPair.Unmarshal(m, b)
 }
 func (m *LabelPair) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
 	return xxx_messageInfo_LabelPair.Marshal(b, m, deterministic)
 }
-func (dst *LabelPair) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_LabelPair.Merge(dst, src)
+func (m *LabelPair) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_LabelPair.Merge(m, src)
 }
 func (m *LabelPair) XXX_Size() int {
 	return xxx_messageInfo_LabelPair.Size(m)
@@ -120,16 +128,17 @@ func (m *Gauge) Reset()         { *m = Gauge{} }
 func (m *Gauge) String() string { return proto.CompactTextString(m) }
 func (*Gauge) ProtoMessage()    {}
 func (*Gauge) Descriptor() ([]byte, []int) {
-	return fileDescriptor_metrics_c97c9a2b9560cb8f, []int{1}
+	return fileDescriptor_6039342a2ba47b72, []int{1}
 }
+
 func (m *Gauge) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Gauge.Unmarshal(m, b)
 }
 func (m *Gauge) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
 	return xxx_messageInfo_Gauge.Marshal(b, m, deterministic)
 }
-func (dst *Gauge) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_Gauge.Merge(dst, src)
+func (m *Gauge) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Gauge.Merge(m, src)
 }
 func (m *Gauge) XXX_Size() int {
 	return xxx_messageInfo_Gauge.Size(m)
@@ -148,26 +157,28 @@ func (m *Gauge) GetValue() float64 {
 }
 
 type Counter struct {
-	Value                *float64 `protobuf:"fixed64,1,opt,name=value" json:"value,omitempty"`
-	XXX_NoUnkeyedLiteral struct{} `json:"-"`
-	XXX_unrecognized     []byte   `json:"-"`
-	XXX_sizecache        int32    `json:"-"`
+	Value                *float64  `protobuf:"fixed64,1,opt,name=value" json:"value,omitempty"`
+	Exemplar             *Exemplar `protobuf:"bytes,2,opt,name=exemplar" json:"exemplar,omitempty"`
+	XXX_NoUnkeyedLiteral struct{}  `json:"-"`
+	XXX_unrecognized     []byte    `json:"-"`
+	XXX_sizecache        int32     `json:"-"`
 }
 
 func (m *Counter) Reset()         { *m = Counter{} }
 func (m *Counter) String() string { return proto.CompactTextString(m) }
 func (*Counter) ProtoMessage()    {}
 func (*Counter) Descriptor() ([]byte, []int) {
-	return fileDescriptor_metrics_c97c9a2b9560cb8f, []int{2}
+	return fileDescriptor_6039342a2ba47b72, []int{2}
 }
+
 func (m *Counter) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Counter.Unmarshal(m, b)
 }
 func (m *Counter) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
 	return xxx_messageInfo_Counter.Marshal(b, m, deterministic)
 }
-func (dst *Counter) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_Counter.Merge(dst, src)
+func (m *Counter) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Counter.Merge(m, src)
 }
 func (m *Counter) XXX_Size() int {
 	return xxx_messageInfo_Counter.Size(m)
@@ -185,6 +196,13 @@ func (m *Counter) GetValue() float64 {
 	return 0
 }
 
+func (m *Counter) GetExemplar() *Exemplar {
+	if m != nil {
+		return m.Exemplar
+	}
+	return nil
+}
+
 type Quantile struct {
 	Quantile             *float64 `protobuf:"fixed64,1,opt,name=quantile" json:"quantile,omitempty"`
 	Value                *float64 `protobuf:"fixed64,2,opt,name=value" json:"value,omitempty"`
@@ -197,16 +215,17 @@ func (m *Quantile) Reset()         { *m = Quantile{} }
 func (m *Quantile) String() string { return proto.CompactTextString(m) }
 func (*Quantile) ProtoMessage()    {}
 func (*Quantile) Descriptor() ([]byte, []int) {
-	return fileDescriptor_metrics_c97c9a2b9560cb8f, []int{3}
+	return fileDescriptor_6039342a2ba47b72, []int{3}
 }
+
 func (m *Quantile) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Quantile.Unmarshal(m, b)
 }
 func (m *Quantile) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
 	return xxx_messageInfo_Quantile.Marshal(b, m, deterministic)
 }
-func (dst *Quantile) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_Quantile.Merge(dst, src)
+func (m *Quantile) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Quantile.Merge(m, src)
 }
 func (m *Quantile) XXX_Size() int {
 	return xxx_messageInfo_Quantile.Size(m)
@@ -244,16 +263,17 @@ func (m *Summary) Reset()         { *m = Summary{} }
 func (m *Summary) String() string { return proto.CompactTextString(m) }
 func (*Summary) ProtoMessage()    {}
 func (*Summary) Descriptor() ([]byte, []int) {
-	return fileDescriptor_metrics_c97c9a2b9560cb8f, []int{4}
+	return fileDescriptor_6039342a2ba47b72, []int{4}
 }
+
 func (m *Summary) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Summary.Unmarshal(m, b)
 }
 func (m *Summary) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
 	return xxx_messageInfo_Summary.Marshal(b, m, deterministic)
 }
-func (dst *Summary) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_Summary.Merge(dst, src)
+func (m *Summary) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Summary.Merge(m, src)
 }
 func (m *Summary) XXX_Size() int {
 	return xxx_messageInfo_Summary.Size(m)
@@ -296,16 +316,17 @@ func (m *Untyped) Reset()         { *m = Untyped{} }
 func (m *Untyped) String() string { return proto.CompactTextString(m) }
 func (*Untyped) ProtoMessage()    {}
 func (*Untyped) Descriptor() ([]byte, []int) {
-	return fileDescriptor_metrics_c97c9a2b9560cb8f, []int{5}
+	return fileDescriptor_6039342a2ba47b72, []int{5}
 }
+
 func (m *Untyped) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Untyped.Unmarshal(m, b)
 }
 func (m *Untyped) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
 	return xxx_messageInfo_Untyped.Marshal(b, m, deterministic)
 }
-func (dst *Untyped) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_Untyped.Merge(dst, src)
+func (m *Untyped) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Untyped.Merge(m, src)
 }
 func (m *Untyped) XXX_Size() int {
 	return xxx_messageInfo_Untyped.Size(m)
@@ -336,16 +357,17 @@ func (m *Histogram) Reset()         { *m = Histogram{} }
 func (m *Histogram) String() string { return proto.CompactTextString(m) }
 func (*Histogram) ProtoMessage()    {}
 func (*Histogram) Descriptor() ([]byte, []int) {
-	return fileDescriptor_metrics_c97c9a2b9560cb8f, []int{6}
+	return fileDescriptor_6039342a2ba47b72, []int{6}
 }
+
 func (m *Histogram) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Histogram.Unmarshal(m, b)
 }
 func (m *Histogram) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
 	return xxx_messageInfo_Histogram.Marshal(b, m, deterministic)
 }
-func (dst *Histogram) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_Histogram.Merge(dst, src)
+func (m *Histogram) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Histogram.Merge(m, src)
 }
 func (m *Histogram) XXX_Size() int {
 	return xxx_messageInfo_Histogram.Size(m)
@@ -378,27 +400,29 @@ func (m *Histogram) GetBucket() []*Bucket {
 }
 
 type Bucket struct {
-	CumulativeCount      *uint64  `protobuf:"varint,1,opt,name=cumulative_count,json=cumulativeCount" json:"cumulative_count,omitempty"`
-	UpperBound           *float64 `protobuf:"fixed64,2,opt,name=upper_bound,json=upperBound" json:"upper_bound,omitempty"`
-	XXX_NoUnkeyedLiteral struct{} `json:"-"`
-	XXX_unrecognized     []byte   `json:"-"`
-	XXX_sizecache        int32    `json:"-"`
+	CumulativeCount      *uint64   `protobuf:"varint,1,opt,name=cumulative_count,json=cumulativeCount" json:"cumulative_count,omitempty"`
+	UpperBound           *float64  `protobuf:"fixed64,2,opt,name=upper_bound,json=upperBound" json:"upper_bound,omitempty"`
+	Exemplar             *Exemplar `protobuf:"bytes,3,opt,name=exemplar" json:"exemplar,omitempty"`
+	XXX_NoUnkeyedLiteral struct{}  `json:"-"`
+	XXX_unrecognized     []byte    `json:"-"`
+	XXX_sizecache        int32     `json:"-"`
 }
 
 func (m *Bucket) Reset()         { *m = Bucket{} }
 func (m *Bucket) String() string { return proto.CompactTextString(m) }
 func (*Bucket) ProtoMessage()    {}
 func (*Bucket) Descriptor() ([]byte, []int) {
-	return fileDescriptor_metrics_c97c9a2b9560cb8f, []int{7}
+	return fileDescriptor_6039342a2ba47b72, []int{7}
 }
+
 func (m *Bucket) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Bucket.Unmarshal(m, b)
 }
 func (m *Bucket) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
 	return xxx_messageInfo_Bucket.Marshal(b, m, deterministic)
 }
-func (dst *Bucket) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_Bucket.Merge(dst, src)
+func (m *Bucket) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Bucket.Merge(m, src)
 }
 func (m *Bucket) XXX_Size() int {
 	return xxx_messageInfo_Bucket.Size(m)
@@ -423,6 +447,68 @@ func (m *Bucket) GetUpperBound() float64 {
 	return 0
 }
 
+func (m *Bucket) GetExemplar() *Exemplar {
+	if m != nil {
+		return m.Exemplar
+	}
+	return nil
+}
+
+type Exemplar struct {
+	Label                []*LabelPair         `protobuf:"bytes,1,rep,name=label" json:"label,omitempty"`
+	Value                *float64             `protobuf:"fixed64,2,opt,name=value" json:"value,omitempty"`
+	Timestamp            *timestamp.Timestamp `protobuf:"bytes,3,opt,name=timestamp" json:"timestamp,omitempty"`
+	XXX_NoUnkeyedLiteral struct{}             `json:"-"`
+	XXX_unrecognized     []byte               `json:"-"`
+	XXX_sizecache        int32                `json:"-"`
+}
+
+func (m *Exemplar) Reset()         { *m = Exemplar{} }
+func (m *Exemplar) String() string { return proto.CompactTextString(m) }
+func (*Exemplar) ProtoMessage()    {}
+func (*Exemplar) Descriptor() ([]byte, []int) {
+	return fileDescriptor_6039342a2ba47b72, []int{8}
+}
+
+func (m *Exemplar) XXX_Unmarshal(b []byte) error {
+	return xxx_messageInfo_Exemplar.Unmarshal(m, b)
+}
+func (m *Exemplar) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	return xxx_messageInfo_Exemplar.Marshal(b, m, deterministic)
+}
+func (m *Exemplar) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Exemplar.Merge(m, src)
+}
+func (m *Exemplar) XXX_Size() int {
+	return xxx_messageInfo_Exemplar.Size(m)
+}
+func (m *Exemplar) XXX_DiscardUnknown() {
+	xxx_messageInfo_Exemplar.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_Exemplar proto.InternalMessageInfo
+
+func (m *Exemplar) GetLabel() []*LabelPair {
+	if m != nil {
+		return m.Label
+	}
+	return nil
+}
+
+func (m *Exemplar) GetValue() float64 {
+	if m != nil && m.Value != nil {
+		return *m.Value
+	}
+	return 0
+}
+
+func (m *Exemplar) GetTimestamp() *timestamp.Timestamp {
+	if m != nil {
+		return m.Timestamp
+	}
+	return nil
+}
+
 type Metric struct {
 	Label                []*LabelPair `protobuf:"bytes,1,rep,name=label" json:"label,omitempty"`
 	Gauge                *Gauge       `protobuf:"bytes,2,opt,name=gauge" json:"gauge,omitempty"`
@@ -440,16 +526,17 @@ func (m *Metric) Reset()         { *m = Metric{} }
 func (m *Metric) String() string { return proto.CompactTextString(m) }
 func (*Metric) ProtoMessage()    {}
 func (*Metric) Descriptor() ([]byte, []int) {
-	return fileDescriptor_metrics_c97c9a2b9560cb8f, []int{8}
+	return fileDescriptor_6039342a2ba47b72, []int{9}
 }
+
 func (m *Metric) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_Metric.Unmarshal(m, b)
 }
 func (m *Metric) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
 	return xxx_messageInfo_Metric.Marshal(b, m, deterministic)
 }
-func (dst *Metric) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_Metric.Merge(dst, src)
+func (m *Metric) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_Metric.Merge(m, src)
 }
 func (m *Metric) XXX_Size() int {
 	return xxx_messageInfo_Metric.Size(m)
@@ -523,16 +610,17 @@ func (m *MetricFamily) Reset()         { *m = MetricFamily{} }
 func (m *MetricFamily) String() string { return proto.CompactTextString(m) }
 func (*MetricFamily) ProtoMessage()    {}
 func (*MetricFamily) Descriptor() ([]byte, []int) {
-	return fileDescriptor_metrics_c97c9a2b9560cb8f, []int{9}
+	return fileDescriptor_6039342a2ba47b72, []int{10}
 }
+
 func (m *MetricFamily) XXX_Unmarshal(b []byte) error {
 	return xxx_messageInfo_MetricFamily.Unmarshal(m, b)
 }
 func (m *MetricFamily) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
 	return xxx_messageInfo_MetricFamily.Marshal(b, m, deterministic)
 }
-func (dst *MetricFamily) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_MetricFamily.Merge(dst, src)
+func (m *MetricFamily) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_MetricFamily.Merge(m, src)
 }
 func (m *MetricFamily) XXX_Size() int {
 	return xxx_messageInfo_MetricFamily.Size(m)
@@ -572,6 +660,7 @@ func (m *MetricFamily) GetMetric() []*Metric {
 }
 
 func init() {
+	proto.RegisterEnum("io.prometheus.client.MetricType", MetricType_name, MetricType_value)
 	proto.RegisterType((*LabelPair)(nil), "io.prometheus.client.LabelPair")
 	proto.RegisterType((*Gauge)(nil), "io.prometheus.client.Gauge")
 	proto.RegisterType((*Counter)(nil), "io.prometheus.client.Counter")
@@ -580,50 +669,55 @@ func init() {
 	proto.RegisterType((*Untyped)(nil), "io.prometheus.client.Untyped")
 	proto.RegisterType((*Histogram)(nil), "io.prometheus.client.Histogram")
 	proto.RegisterType((*Bucket)(nil), "io.prometheus.client.Bucket")
+	proto.RegisterType((*Exemplar)(nil), "io.prometheus.client.Exemplar")
 	proto.RegisterType((*Metric)(nil), "io.prometheus.client.Metric")
 	proto.RegisterType((*MetricFamily)(nil), "io.prometheus.client.MetricFamily")
-	proto.RegisterEnum("io.prometheus.client.MetricType", MetricType_name, MetricType_value)
 }
 
-func init() { proto.RegisterFile("metrics.proto", fileDescriptor_metrics_c97c9a2b9560cb8f) }
-
-var fileDescriptor_metrics_c97c9a2b9560cb8f = []byte{
-	// 591 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xac, 0x54, 0x4f, 0x4f, 0xdb, 0x4e,
-	0x14, 0xfc, 0x99, 0xd8, 0x09, 0x7e, 0x86, 0x5f, 0xad, 0x15, 0x07, 0xab, 0x2d, 0x25, 0xcd, 0x89,
-	0xf6, 0x10, 0x54, 0x04, 0xaa, 0x44, 0xdb, 0x03, 0x50, 0x1a, 0x2a, 0xd5, 0x40, 0x37, 0xc9, 0x81,
-	0x5e, 0xac, 0x8d, 0x59, 0x25, 0x56, 0xbd, 0xb6, 0x6b, 0xef, 0x22, 0xe5, 0xdc, 0x43, 0xbf, 0x47,
-	0xbf, 0x68, 0xab, 0xfd, 0xe3, 0x18, 0x24, 0xc3, 0xa9, 0xb7, 0xb7, 0xf3, 0x66, 0xde, 0x8e, 0x77,
-	0xc7, 0x0b, 0x9b, 0x8c, 0xf2, 0x32, 0x89, 0xab, 0x61, 0x51, 0xe6, 0x3c, 0x47, 0x5b, 0x49, 0x2e,
-	0x2b, 0x46, 0xf9, 0x82, 0x8a, 0x6a, 0x18, 0xa7, 0x09, 0xcd, 0xf8, 0xe0, 0x10, 0xdc, 0x2f, 0x64,
-	0x46, 0xd3, 0x2b, 0x92, 0x94, 0x08, 0x81, 0x9d, 0x11, 0x46, 0x03, 0xab, 0x6f, 0xed, 0xba, 0x58,
-	0xd5, 0x68, 0x0b, 0x9c, 0x5b, 0x92, 0x0a, 0x1a, 0xac, 0x29, 0x50, 0x2f, 0x06, 0xdb, 0xe0, 0x8c,
-	0x88, 0x98, 0xdf, 0x69, 0x4b, 0x8d, 0x55, 0xb7, 0x77, 0xa0, 0x77, 0x9a, 0x8b, 0x8c, 0xd3, 0xf2,
-	0x01, 0xc2, 0x7b, 0x58, 0xff, 0x2a, 0x48, 0xc6, 0x93, 0x94, 0xa2, 0xa7, 0xb0, 0xfe, 0xc3, 0xd4,
-	0x86, 0xb4, 0x5a, 0xdf, 0xdf, 0x7d, 0xa5, 0xfe, 0x65, 0x41, 0x6f, 0x2c, 0x18, 0x23, 0xe5, 0x12,
-	0xbd, 0x84, 0x8d, 0x8a, 0xb0, 0x22, 0xa5, 0x51, 0x2c, 0x77, 0x54, 0x13, 0x6c, 0xec, 0x69, 0x4c,
-	0x99, 0x40, 0xdb, 0x00, 0x86, 0x52, 0x09, 0x66, 0x26, 0xb9, 0x1a, 0x19, 0x0b, 0x86, 0x8e, 0xee,
-	0xec, 0xdf, 0xe9, 0x77, 0x76, 0xbd, 0xfd, 0x17, 0xc3, 0xb6, 0xb3, 0x1a, 0xd6, 0x8e, 0x1b, 0x7f,
-	0xf2, 0x43, 0xa7, 0x19, 0x5f, 0x16, 0xf4, 0xe6, 0x81, 0x0f, 0xfd, 0x69, 0x81, 0x7b, 0x9e, 0x54,
-	0x3c, 0x9f, 0x97, 0x84, 0xfd, 0x03, 0xb3, 0x07, 0xd0, 0x9d, 0x89, 0xf8, 0x3b, 0xe5, 0xc6, 0xea,
-	0xf3, 0x76, 0xab, 0x27, 0x8a, 0x83, 0x0d, 0x77, 0x30, 0x81, 0xae, 0x46, 0xd0, 0x2b, 0xf0, 0x63,
-	0xc1, 0x44, 0x4a, 0x78, 0x72, 0x7b, 0xdf, 0xc5, 0x93, 0x06, 0xd7, 0x4e, 0x76, 0xc0, 0x13, 0x45,
-	0x41, 0xcb, 0x68, 0x96, 0x8b, 0xec, 0xc6, 0x58, 0x01, 0x05, 0x9d, 0x48, 0x64, 0xf0, 0x67, 0x0d,
-	0xba, 0xa1, 0xca, 0x18, 0x3a, 0x04, 0x27, 0x95, 0x31, 0x0a, 0x2c, 0xe5, 0x6a, 0xa7, 0xdd, 0xd5,
-	0x2a, 0x69, 0x58, 0xb3, 0xd1, 0x1b, 0x70, 0xe6, 0x32, 0x46, 0x6a, 0xb8, 0xb7, 0xff, 0xac, 0x5d,
-	0xa6, 0x92, 0x86, 0x35, 0x13, 0xbd, 0x85, 0x5e, 0xac, 0xa3, 0x15, 0x74, 0x94, 0x68, 0xbb, 0x5d,
-	0x64, 0xf2, 0x87, 0x6b, 0xb6, 0x14, 0x56, 0x3a, 0x33, 0x81, 0xfd, 0x98, 0xd0, 0x04, 0x0b, 0xd7,
-	0x6c, 0x29, 0x14, 0xfa, 0x8e, 0x03, 0xe7, 0x31, 0xa1, 0x09, 0x02, 0xae, 0xd9, 0xe8, 0x03, 0xb8,
-	0x8b, 0xfa, 0xea, 0x83, 0x9e, 0x92, 0x3e, 0x70, 0x30, 0xab, 0x84, 0xe0, 0x46, 0x21, 0xc3, 0xc2,
-	0x13, 0x46, 0x2b, 0x4e, 0x58, 0x11, 0xb1, 0x2a, 0xe8, 0xf6, 0xad, 0xdd, 0x0e, 0xf6, 0x56, 0x58,
-	0x58, 0x0d, 0x7e, 0x5b, 0xb0, 0xa1, 0x6f, 0xe0, 0x13, 0x61, 0x49, 0xba, 0x6c, 0xfd, 0x83, 0x11,
-	0xd8, 0x0b, 0x9a, 0x16, 0xe6, 0x07, 0x56, 0x35, 0x3a, 0x00, 0x5b, 0x7a, 0x54, 0x47, 0xf8, 0xff,
-	0x7e, 0xbf, 0xdd, 0x95, 0x9e, 0x3c, 0x59, 0x16, 0x14, 0x2b, 0xb6, 0x0c, 0x9f, 0x7e, 0x53, 0x02,
-	0xfb, 0xb1, 0xf0, 0x69, 0x1d, 0x36, 0xdc, 0xd7, 0x21, 0x40, 0x33, 0x09, 0x79, 0xd0, 0x3b, 0xbd,
-	0x9c, 0x5e, 0x4c, 0xce, 0xb0, 0xff, 0x1f, 0x72, 0xc1, 0x19, 0x1d, 0x4f, 0x47, 0x67, 0xbe, 0x25,
-	0xf1, 0xf1, 0x34, 0x0c, 0x8f, 0xf1, 0xb5, 0xbf, 0x26, 0x17, 0xd3, 0x8b, 0xc9, 0xf5, 0xd5, 0xd9,
-	0x47, 0xbf, 0x83, 0x36, 0xc1, 0x3d, 0xff, 0x3c, 0x9e, 0x5c, 0x8e, 0xf0, 0x71, 0xe8, 0xdb, 0x27,
-	0x18, 0x5a, 0x5f, 0xb2, 0x6f, 0x47, 0xf3, 0x84, 0x2f, 0xc4, 0x6c, 0x18, 0xe7, 0x6c, 0xaf, 0xe9,
-	0xee, 0xe9, 0x6e, 0xc4, 0xf2, 0x1b, 0x9a, 0xee, 0xcd, 0xf3, 0x77, 0x49, 0x1e, 0x35, 0xdd, 0x48,
-	0x77, 0xff, 0x06, 0x00, 0x00, 0xff, 0xff, 0x45, 0x21, 0x7f, 0x64, 0x2b, 0x05, 0x00, 0x00,
+func init() { proto.RegisterFile("metrics.proto", fileDescriptor_6039342a2ba47b72) }
+
+var fileDescriptor_6039342a2ba47b72 = []byte{
+	// 665 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xac, 0x54, 0xcd, 0x6e, 0xd3, 0x4c,
+	0x14, 0xfd, 0xdc, 0x38, 0x3f, 0xbe, 0x69, 0x3f, 0xa2, 0x51, 0x17, 0x56, 0xa1, 0x24, 0x78, 0x55,
+	0x58, 0x38, 0xa2, 0x6a, 0x05, 0x2a, 0xb0, 0x68, 0x4b, 0x48, 0x91, 0x48, 0x5b, 0x26, 0xc9, 0xa2,
+	0xb0, 0x88, 0x1c, 0x77, 0x70, 0x2c, 0x3c, 0xb1, 0xb1, 0x67, 0x2a, 0xb2, 0x66, 0xc1, 0x16, 0x5e,
+	0x81, 0x17, 0x05, 0xcd, 0x8f, 0x6d, 0x2a, 0xb9, 0x95, 0x40, 0xec, 0x66, 0xee, 0x3d, 0xe7, 0xfa,
+	0xcc, 0xf8, 0x9c, 0x81, 0x0d, 0x4a, 0x58, 0x1a, 0xfa, 0x99, 0x9b, 0xa4, 0x31, 0x8b, 0xd1, 0x66,
+	0x18, 0x8b, 0x15, 0x25, 0x6c, 0x41, 0x78, 0xe6, 0xfa, 0x51, 0x48, 0x96, 0x6c, 0xab, 0x1b, 0xc4,
+	0x71, 0x10, 0x91, 0xbe, 0xc4, 0xcc, 0xf9, 0x87, 0x3e, 0x0b, 0x29, 0xc9, 0x98, 0x47, 0x13, 0x45,
+	0x73, 0xf6, 0xc1, 0x7a, 0xe3, 0xcd, 0x49, 0x74, 0xee, 0x85, 0x29, 0x42, 0x60, 0x2e, 0x3d, 0x4a,
+	0x6c, 0xa3, 0x67, 0xec, 0x58, 0x58, 0xae, 0xd1, 0x26, 0xd4, 0xaf, 0xbc, 0x88, 0x13, 0x7b, 0x4d,
+	0x16, 0xd5, 0xc6, 0xd9, 0x86, 0xfa, 0xd0, 0xe3, 0xc1, 0x6f, 0x6d, 0xc1, 0x31, 0xf2, 0xf6, 0x7b,
+	0x68, 0x1e, 0xc7, 0x7c, 0xc9, 0x48, 0x5a, 0x0d, 0x40, 0x07, 0xd0, 0x22, 0x9f, 0x09, 0x4d, 0x22,
+	0x2f, 0x95, 0x83, 0xdb, 0xbb, 0xf7, 0xdd, 0xaa, 0x03, 0xb8, 0x03, 0x8d, 0xc2, 0x05, 0xde, 0x79,
+	0x0e, 0xad, 0xb7, 0xdc, 0x5b, 0xb2, 0x30, 0x22, 0x68, 0x0b, 0x5a, 0x9f, 0xf4, 0x5a, 0x7f, 0xa0,
+	0xd8, 0x5f, 0x57, 0x5e, 0x48, 0xfb, 0x6a, 0x40, 0x73, 0xcc, 0x29, 0xf5, 0xd2, 0x15, 0x7a, 0x00,
+	0xeb, 0x99, 0x47, 0x93, 0x88, 0xcc, 0x7c, 0xa1, 0x56, 0x4e, 0x30, 0x71, 0x5b, 0xd5, 0xe4, 0x01,
+	0xd0, 0x36, 0x80, 0x86, 0x64, 0x9c, 0xea, 0x49, 0x96, 0xaa, 0x8c, 0x39, 0x15, 0xe7, 0x28, 0xbe,
+	0x5f, 0xeb, 0xd5, 0x6e, 0x3e, 0x47, 0xae, 0xb8, 0xd4, 0xe7, 0x74, 0xa1, 0x39, 0x5d, 0xb2, 0x55,
+	0x42, 0x2e, 0x6f, 0xb8, 0xc5, 0x2f, 0x06, 0x58, 0x27, 0x61, 0xc6, 0xe2, 0x20, 0xf5, 0xe8, 0x3f,
+	0x10, 0xbb, 0x07, 0x8d, 0x39, 0xf7, 0x3f, 0x12, 0xa6, 0xa5, 0xde, 0xab, 0x96, 0x7a, 0x24, 0x31,
+	0x58, 0x63, 0x9d, 0x6f, 0x06, 0x34, 0x54, 0x09, 0x3d, 0x84, 0x8e, 0xcf, 0x29, 0x8f, 0x3c, 0x16,
+	0x5e, 0x5d, 0x97, 0x71, 0xa7, 0xac, 0x2b, 0x29, 0x5d, 0x68, 0xf3, 0x24, 0x21, 0xe9, 0x6c, 0x1e,
+	0xf3, 0xe5, 0xa5, 0xd6, 0x02, 0xb2, 0x74, 0x24, 0x2a, 0xd7, 0x1c, 0x50, 0xfb, 0x43, 0x07, 0x7c,
+	0x37, 0xa0, 0x95, 0x97, 0xd1, 0x3e, 0xd4, 0x23, 0xe1, 0x60, 0xdb, 0x90, 0x87, 0xea, 0x56, 0x4f,
+	0x29, 0x4c, 0x8e, 0x15, 0xba, 0xda, 0x1d, 0xe8, 0x29, 0x58, 0x45, 0x42, 0xb4, 0xac, 0x2d, 0x57,
+	0x65, 0xc8, 0xcd, 0x33, 0xe4, 0x4e, 0x72, 0x04, 0x2e, 0xc1, 0xce, 0xcf, 0x35, 0x68, 0x8c, 0x64,
+	0x22, 0xff, 0x56, 0xd1, 0x63, 0xa8, 0x07, 0x22, 0x53, 0x3a, 0x10, 0x77, 0xab, 0x69, 0x32, 0x76,
+	0x58, 0x21, 0xd1, 0x13, 0x68, 0xfa, 0x2a, 0x67, 0x5a, 0xec, 0x76, 0x35, 0x49, 0x87, 0x11, 0xe7,
+	0x68, 0x41, 0xcc, 0x54, 0x08, 0x6c, 0xf3, 0x36, 0xa2, 0x4e, 0x0a, 0xce, 0xd1, 0x82, 0xc8, 0x95,
+	0x69, 0xed, 0xfa, 0x6d, 0x44, 0xed, 0x6c, 0x9c, 0xa3, 0xd1, 0x0b, 0xb0, 0x16, 0xb9, 0x97, 0xed,
+	0xa6, 0xa4, 0xde, 0x70, 0x31, 0x85, 0xe5, 0x71, 0xc9, 0x10, 0xee, 0x2f, 0xee, 0x7a, 0x46, 0x33,
+	0xbb, 0xd1, 0x33, 0x76, 0x6a, 0xb8, 0x5d, 0xd4, 0x46, 0x99, 0xf3, 0xc3, 0x80, 0x75, 0xf5, 0x07,
+	0x5e, 0x79, 0x34, 0x8c, 0x56, 0x95, 0xcf, 0x19, 0x02, 0x73, 0x41, 0xa2, 0x44, 0xbf, 0x66, 0x72,
+	0x8d, 0xf6, 0xc0, 0x14, 0x1a, 0xe5, 0x15, 0xfe, 0xbf, 0xdb, 0xab, 0x56, 0xa5, 0x26, 0x4f, 0x56,
+	0x09, 0xc1, 0x12, 0x2d, 0xd2, 0xa4, 0x5e, 0x60, 0xdb, 0xbc, 0x2d, 0x4d, 0x8a, 0x87, 0x35, 0xf6,
+	0xd1, 0x08, 0xa0, 0x9c, 0x84, 0xda, 0xd0, 0x3c, 0x3e, 0x9b, 0x9e, 0x4e, 0x06, 0xb8, 0xf3, 0x1f,
+	0xb2, 0xa0, 0x3e, 0x3c, 0x9c, 0x0e, 0x07, 0x1d, 0x43, 0xd4, 0xc7, 0xd3, 0xd1, 0xe8, 0x10, 0x5f,
+	0x74, 0xd6, 0xc4, 0x66, 0x7a, 0x3a, 0xb9, 0x38, 0x1f, 0xbc, 0xec, 0xd4, 0xd0, 0x06, 0x58, 0x27,
+	0xaf, 0xc7, 0x93, 0xb3, 0x21, 0x3e, 0x1c, 0x75, 0xcc, 0x23, 0x0c, 0x95, 0xef, 0xfe, 0xbb, 0x83,
+	0x20, 0x64, 0x0b, 0x3e, 0x77, 0xfd, 0x98, 0xf6, 0xcb, 0x6e, 0x5f, 0x75, 0x67, 0x34, 0xbe, 0x24,
+	0x51, 0x3f, 0x88, 0x9f, 0x85, 0xf1, 0xac, 0xec, 0xce, 0x54, 0xf7, 0x57, 0x00, 0x00, 0x00, 0xff,
+	0xff, 0xd0, 0x84, 0x91, 0x73, 0x59, 0x06, 0x00, 0x00,
 }

vendor/github.com/prometheus/common/expfmt/encode.go

@@ -30,17 +30,38 @@ type Encoder interface {
 	Encode(*dto.MetricFamily) error
 }
 
-type encoder func(*dto.MetricFamily) error
+// Closer is implemented by Encoders that need to be closed to finalize
+// encoding. (For example, OpenMetrics needs a final `# EOF` line.)
+//
+// Note that all Encoder implementations returned from this package implement
+// Closer, too, even if the Close call is a no-op. This happens in preparation
+// for adding a Close method to the Encoder interface directly in a (mildly
+// breaking) release in the future.
+type Closer interface {
+	Close() error
+}
+
+type encoderCloser struct {
+	encode func(*dto.MetricFamily) error
+	close  func() error
+}
 
-func (e encoder) Encode(v *dto.MetricFamily) error {
-	return e(v)
+func (ec encoderCloser) Encode(v *dto.MetricFamily) error {
+	return ec.encode(v)
 }
 
-// Negotiate returns the Content-Type based on the given Accept header.
-// If no appropriate accepted type is found, FmtText is returned.
+func (ec encoderCloser) Close() error {
+	return ec.close()
+}
+
+// Negotiate returns the Content-Type based on the given Accept header. If no
+// appropriate accepted type is found, FmtText is returned (which is the
+// Prometheus text format). This function will never negotiate FmtOpenMetrics,
+// as the support is still experimental. To include the option to negotiate
+// FmtOpenMetrics, use NegotiateOpenMetrics.
 func Negotiate(h http.Header) Format {
 	for _, ac := range goautoneg.ParseAccept(h.Get(hdrAccept)) {
-		// Check for protocol buffer
+		ver := ac.Params["version"]
 		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
 			switch ac.Params["encoding"] {
 			case "delimited":
@@ -51,38 +72,91 @@ func Negotiate(h http.Header) Format {
 				return FmtProtoCompact
 			}
 		}
-		// Check for text format.
+		if ac.Type == "text" && ac.SubType == "plain" && (ver == TextVersion || ver == "") {
+			return FmtText
+		}
+	}
+	return FmtText
+}
+
+// NegotiateIncludingOpenMetrics works like Negotiate but includes
+// FmtOpenMetrics as an option for the result. Note that this function is
+// temporary and will disappear once FmtOpenMetrics is fully supported and as
+// such may be negotiated by the normal Negotiate function.
+func NegotiateIncludingOpenMetrics(h http.Header) Format {
+	for _, ac := range goautoneg.ParseAccept(h.Get(hdrAccept)) {
 		ver := ac.Params["version"]
+		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
+			switch ac.Params["encoding"] {
+			case "delimited":
+				return FmtProtoDelim
+			case "text":
+				return FmtProtoText
+			case "compact-text":
+				return FmtProtoCompact
+			}
+		}
 		if ac.Type == "text" && ac.SubType == "plain" && (ver == TextVersion || ver == "") {
 			return FmtText
 		}
+		if ac.Type+"/"+ac.SubType == OpenMetricsType && (ver == OpenMetricsVersion || ver == "") {
+			return FmtOpenMetrics
+		}
 	}
 	return FmtText
 }
 
-// NewEncoder returns a new encoder based on content type negotiation.
+// NewEncoder returns a new encoder based on content type negotiation. All
+// Encoder implementations returned by NewEncoder also implement Closer, and
+// callers should always call the Close method. It is currently only required
+// for FmtOpenMetrics, but a future (breaking) release will add the Close method
+// to the Encoder interface directly. The current version of the Encoder
+// interface is kept for backwards compatibility.
 func NewEncoder(w io.Writer, format Format) Encoder {
 	switch format {
 	case FmtProtoDelim:
-		return encoder(func(v *dto.MetricFamily) error {
-			_, err := pbutil.WriteDelimited(w, v)
-			return err
-		})
+		return encoderCloser{
+			encode: func(v *dto.MetricFamily) error {
+				_, err := pbutil.WriteDelimited(w, v)
+				return err
+			},
+			close: func() error { return nil },
+		}
 	case FmtProtoCompact:
-		return encoder(func(v *dto.MetricFamily) error {
-			_, err := fmt.Fprintln(w, v.String())
-			return err
-		})
+		return encoderCloser{
+			encode: func(v *dto.MetricFamily) error {
+				_, err := fmt.Fprintln(w, v.String())
+				return err
+			},
+			close: func() error { return nil },
+		}
 	case FmtProtoText:
-		return encoder(func(v *dto.MetricFamily) error {
-			_, err := fmt.Fprintln(w, proto.MarshalTextString(v))
-			return err
-		})
+		return encoderCloser{
+			encode: func(v *dto.MetricFamily) error {
+				_, err := fmt.Fprintln(w, proto.MarshalTextString(v))
+				return err
+			},
+			close: func() error { return nil },
+		}
 	case FmtText:
-		return encoder(func(v *dto.MetricFamily) error {
-			_, err := MetricFamilyToText(w, v)
-			return err
-		})
+		return encoderCloser{
+			encode: func(v *dto.MetricFamily) error {
+				_, err := MetricFamilyToText(w, v)
+				return err
+			},
+			close: func() error { return nil },
+		}
+	case FmtOpenMetrics:
+		return encoderCloser{
+			encode: func(v *dto.MetricFamily) error {
+				_, err := MetricFamilyToOpenMetrics(w, v)
+				return err
+			},
+			close: func() error {
+				_, err := FinalizeOpenMetrics(w)
+				return err
+			},
+		}
 	}
-	panic("expfmt.NewEncoder: unknown format")
+	panic(fmt.Errorf("expfmt.NewEncoder: unknown format %q", format))
 }

vendor/github.com/prometheus/common/expfmt/expfmt.go

@@ -19,10 +19,12 @@ type Format string
 
 // Constants to assemble the Content-Type values for the different wire protocols.
 const (
-	TextVersion   = "0.0.4"
-	ProtoType     = `application/vnd.google.protobuf`
-	ProtoProtocol = `io.prometheus.client.MetricFamily`
-	ProtoFmt      = ProtoType + "; proto=" + ProtoProtocol + ";"
+	TextVersion        = "0.0.4"
+	ProtoType          = `application/vnd.google.protobuf`
+	ProtoProtocol      = `io.prometheus.client.MetricFamily`
+	ProtoFmt           = ProtoType + "; proto=" + ProtoProtocol + ";"
+	OpenMetricsType    = `application/openmetrics-text`
+	OpenMetricsVersion = "0.0.1"
 
 	// The Content-Type values for the different wire protocols.
 	FmtUnknown      Format = `<unknown>`
@@ -30,6 +32,7 @@ const (
 	FmtProtoDelim   Format = ProtoFmt + ` encoding=delimited`
 	FmtProtoText    Format = ProtoFmt + ` encoding=text`
 	FmtProtoCompact Format = ProtoFmt + ` encoding=compact-text`
+	FmtOpenMetrics  Format = OpenMetricsType + `; version=` + OpenMetricsVersion + `; charset=utf-8`
 )
 
 const (

vendor/github.com/prometheus/common/expfmt/openmetrics_create.go

@@ -0,0 +1,527 @@
+// Copyright 2020 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"math"
+	"strconv"
+	"strings"
+
+	"github.com/golang/protobuf/ptypes"
+	"github.com/prometheus/common/model"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// MetricFamilyToOpenMetrics converts a MetricFamily proto message into the
+// OpenMetrics text format and writes the resulting lines to 'out'. It returns
+// the number of bytes written and any error encountered. The output will have
+// the same order as the input, no further sorting is performed. Furthermore,
+// this function assumes the input is already sanitized and does not perform any
+// sanity checks. If the input contains duplicate metrics or invalid metric or
+// label names, the conversion will result in invalid text format output.
+//
+// This function fulfills the type 'expfmt.encoder'.
+//
+// Note that OpenMetrics requires a final `# EOF` line. Since this function acts
+// on individual metric families, it is the responsibility of the caller to
+// append this line to 'out' once all metric families have been written.
+// Conveniently, this can be done by calling FinalizeOpenMetrics.
+//
+// The output should be fully OpenMetrics compliant. However, there are a few
+// missing features and peculiarities to avoid complications when switching from
+// Prometheus to OpenMetrics or vice versa:
+//
+// - Counters are expected to have the `_total` suffix in their metric name. In
+//   the output, the suffix will be truncated from the `# TYPE` and `# HELP`
+//   line. A counter with a missing `_total` suffix is not an error. However,
+//   its type will be set to `unknown` in that case to avoid invalid OpenMetrics
+//   output.
+//
+// - No support for the following (optional) features: `# UNIT` line, `_created`
+//   line, info type, stateset type, gaugehistogram type.
+//
+// - The size of exemplar labels is not checked (i.e. it's possible to create
+//   exemplars that are larger than allowed by the OpenMetrics specification).
+//
+// - The value of Counters is not checked. (OpenMetrics doesn't allow counters
+//   with a `NaN` value.)
+func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int, err error) {
+	name := in.GetName()
+	if name == "" {
+		return 0, fmt.Errorf("MetricFamily has no name: %s", in)
+	}
+
+	// Try the interface upgrade. If it doesn't work, we'll use a
+	// bufio.Writer from the sync.Pool.
+	w, ok := out.(enhancedWriter)
+	if !ok {
+		b := bufPool.Get().(*bufio.Writer)
+		b.Reset(out)
+		w = b
+		defer func() {
+			bErr := b.Flush()
+			if err == nil {
+				err = bErr
+			}
+			bufPool.Put(b)
+		}()
+	}
+
+	var (
+		n          int
+		metricType = in.GetType()
+		shortName  = name
+	)
+	if metricType == dto.MetricType_COUNTER && strings.HasSuffix(shortName, "_total") {
+		shortName = name[:len(name)-6]
+	}
+
+	// Comments, first HELP, then TYPE.
+	if in.Help != nil {
+		n, err = w.WriteString("# HELP ")
+		written += n
+		if err != nil {
+			return
+		}
+		n, err = w.WriteString(shortName)
+		written += n
+		if err != nil {
+			return
+		}
+		err = w.WriteByte(' ')
+		written++
+		if err != nil {
+			return
+		}
+		n, err = writeEscapedString(w, *in.Help, true)
+		written += n
+		if err != nil {
+			return
+		}
+		err = w.WriteByte('\n')
+		written++
+		if err != nil {
+			return
+		}
+	}
+	n, err = w.WriteString("# TYPE ")
+	written += n
+	if err != nil {
+		return
+	}
+	n, err = w.WriteString(shortName)
+	written += n
+	if err != nil {
+		return
+	}
+	switch metricType {
+	case dto.MetricType_COUNTER:
+		if strings.HasSuffix(name, "_total") {
+			n, err = w.WriteString(" counter\n")
+		} else {
+			n, err = w.WriteString(" unknown\n")
+		}
+	case dto.MetricType_GAUGE:
+		n, err = w.WriteString(" gauge\n")
+	case dto.MetricType_SUMMARY:
+		n, err = w.WriteString(" summary\n")
+	case dto.MetricType_UNTYPED:
+		n, err = w.WriteString(" unknown\n")
+	case dto.MetricType_HISTOGRAM:
+		n, err = w.WriteString(" histogram\n")
+	default:
+		return written, fmt.Errorf("unknown metric type %s", metricType.String())
+	}
+	written += n
+	if err != nil {
+		return
+	}
+
+	// Finally the samples, one line for each.
+	for _, metric := range in.Metric {
+		switch metricType {
+		case dto.MetricType_COUNTER:
+			if metric.Counter == nil {
+				return written, fmt.Errorf(
+					"expected counter in metric %s %s", name, metric,
+				)
+			}
+			// Note that we have ensured above that either the name
+			// ends on `_total` or that the rendered type is
+			// `unknown`. Therefore, no `_total` must be added here.
+			n, err = writeOpenMetricsSample(
+				w, name, "", metric, "", 0,
+				metric.Counter.GetValue(), 0, false,
+				metric.Counter.Exemplar,
+			)
+		case dto.MetricType_GAUGE:
+			if metric.Gauge == nil {
+				return written, fmt.Errorf(
+					"expected gauge in metric %s %s", name, metric,
+				)
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "", metric, "", 0,
+				metric.Gauge.GetValue(), 0, false,
+				nil,
+			)
+		case dto.MetricType_UNTYPED:
+			if metric.Untyped == nil {
+				return written, fmt.Errorf(
+					"expected untyped in metric %s %s", name, metric,
+				)
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "", metric, "", 0,
+				metric.Untyped.GetValue(), 0, false,
+				nil,
+			)
+		case dto.MetricType_SUMMARY:
+			if metric.Summary == nil {
+				return written, fmt.Errorf(
+					"expected summary in metric %s %s", name, metric,
+				)
+			}
+			for _, q := range metric.Summary.Quantile {
+				n, err = writeOpenMetricsSample(
+					w, name, "", metric,
+					model.QuantileLabel, q.GetQuantile(),
+					q.GetValue(), 0, false,
+					nil,
+				)
+				written += n
+				if err != nil {
+					return
+				}
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "_sum", metric, "", 0,
+				metric.Summary.GetSampleSum(), 0, false,
+				nil,
+			)
+			written += n
+			if err != nil {
+				return
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "_count", metric, "", 0,
+				0, metric.Summary.GetSampleCount(), true,
+				nil,
+			)
+		case dto.MetricType_HISTOGRAM:
+			if metric.Histogram == nil {
+				return written, fmt.Errorf(
+					"expected histogram in metric %s %s", name, metric,
+				)
+			}
+			infSeen := false
+			for _, b := range metric.Histogram.Bucket {
+				n, err = writeOpenMetricsSample(
+					w, name, "_bucket", metric,
+					model.BucketLabel, b.GetUpperBound(),
+					0, b.GetCumulativeCount(), true,
+					b.Exemplar,
+				)
+				written += n
+				if err != nil {
+					return
+				}
+				if math.IsInf(b.GetUpperBound(), +1) {
+					infSeen = true
+				}
+			}
+			if !infSeen {
+				n, err = writeOpenMetricsSample(
+					w, name, "_bucket", metric,
+					model.BucketLabel, math.Inf(+1),
+					0, metric.Histogram.GetSampleCount(), true,
+					nil,
+				)
+				written += n
+				if err != nil {
+					return
+				}
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "_sum", metric, "", 0,
+				metric.Histogram.GetSampleSum(), 0, false,
+				nil,
+			)
+			written += n
+			if err != nil {
+				return
+			}
+			n, err = writeOpenMetricsSample(
+				w, name, "_count", metric, "", 0,
+				0, metric.Histogram.GetSampleCount(), true,
+				nil,
+			)
+		default:
+			return written, fmt.Errorf(
+				"unexpected type in metric %s %s", name, metric,
+			)
+		}
+		written += n
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+// FinalizeOpenMetrics writes the final `# EOF\n` line required by OpenMetrics.
+func FinalizeOpenMetrics(w io.Writer) (written int, err error) {
+	return w.Write([]byte("# EOF\n"))
+}
+
+// writeOpenMetricsSample writes a single sample in OpenMetrics text format to
+// w, given the metric name, the metric proto message itself, optionally an
+// additional label name with a float64 value (use empty string as label name if
+// not required), the value (optionally as float64 or uint64, determined by
+// useIntValue), and optionally an exemplar (use nil if not required). The
+// function returns the number of bytes written and any error encountered.
+func writeOpenMetricsSample(
+	w enhancedWriter,
+	name, suffix string,
+	metric *dto.Metric,
+	additionalLabelName string, additionalLabelValue float64,
+	floatValue float64, intValue uint64, useIntValue bool,
+	exemplar *dto.Exemplar,
+) (int, error) {
+	var written int
+	n, err := w.WriteString(name)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	if suffix != "" {
+		n, err = w.WriteString(suffix)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	n, err = writeOpenMetricsLabelPairs(
+		w, metric.Label, additionalLabelName, additionalLabelValue,
+	)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	err = w.WriteByte(' ')
+	written++
+	if err != nil {
+		return written, err
+	}
+	if useIntValue {
+		n, err = writeUint(w, intValue)
+	} else {
+		n, err = writeOpenMetricsFloat(w, floatValue)
+	}
+	written += n
+	if err != nil {
+		return written, err
+	}
+	if metric.TimestampMs != nil {
+		err = w.WriteByte(' ')
+		written++
+		if err != nil {
+			return written, err
+		}
+		// TODO(beorn7): Format this directly without converting to a float first.
+		n, err = writeOpenMetricsFloat(w, float64(*metric.TimestampMs)/1000)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	if exemplar != nil {
+		n, err = writeExemplar(w, exemplar)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	err = w.WriteByte('\n')
+	written++
+	if err != nil {
+		return written, err
+	}
+	return written, nil
+}
+
+// writeOpenMetricsLabelPairs works like writeOpenMetrics but formats the float
+// in OpenMetrics style.
+func writeOpenMetricsLabelPairs(
+	w enhancedWriter,
+	in []*dto.LabelPair,
+	additionalLabelName string, additionalLabelValue float64,
+) (int, error) {
+	if len(in) == 0 && additionalLabelName == "" {
+		return 0, nil
+	}
+	var (
+		written   int
+		separator byte = '{'
+	)
+	for _, lp := range in {
+		err := w.WriteByte(separator)
+		written++
+		if err != nil {
+			return written, err
+		}
+		n, err := w.WriteString(lp.GetName())
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = w.WriteString(`="`)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = writeEscapedString(w, lp.GetValue(), true)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		err = w.WriteByte('"')
+		written++
+		if err != nil {
+			return written, err
+		}
+		separator = ','
+	}
+	if additionalLabelName != "" {
+		err := w.WriteByte(separator)
+		written++
+		if err != nil {
+			return written, err
+		}
+		n, err := w.WriteString(additionalLabelName)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = w.WriteString(`="`)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		n, err = writeOpenMetricsFloat(w, additionalLabelValue)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		err = w.WriteByte('"')
+		written++
+		if err != nil {
+			return written, err
+		}
+	}
+	err := w.WriteByte('}')
+	written++
+	if err != nil {
+		return written, err
+	}
+	return written, nil
+}
+
+// writeExemplar writes the provided exemplar in OpenMetrics format to w. The
+// function returns the number of bytes written and any error encountered.
+func writeExemplar(w enhancedWriter, e *dto.Exemplar) (int, error) {
+	written := 0
+	n, err := w.WriteString(" # ")
+	written += n
+	if err != nil {
+		return written, err
+	}
+	n, err = writeOpenMetricsLabelPairs(w, e.Label, "", 0)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	err = w.WriteByte(' ')
+	written++
+	if err != nil {
+		return written, err
+	}
+	n, err = writeOpenMetricsFloat(w, e.GetValue())
+	written += n
+	if err != nil {
+		return written, err
+	}
+	if e.Timestamp != nil {
+		err = w.WriteByte(' ')
+		written++
+		if err != nil {
+			return written, err
+		}
+		ts, err := ptypes.Timestamp((*e).Timestamp)
+		if err != nil {
+			return written, err
+		}
+		// TODO(beorn7): Format this directly from components of ts to
+		// avoid overflow/underflow and precision issues of the float
+		// conversion.
+		n, err = writeOpenMetricsFloat(w, float64(ts.UnixNano())/1e9)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	return written, nil
+}
+
+// writeOpenMetricsFloat works like writeFloat but appends ".0" if the resulting
+// number would otherwise contain neither a "." nor an "e".
+func writeOpenMetricsFloat(w enhancedWriter, f float64) (int, error) {
+	switch {
+	case f == 1:
+		return w.WriteString("1.0")
+	case f == 0:
+		return w.WriteString("0.0")
+	case f == -1:
+		return w.WriteString("-1.0")
+	case math.IsNaN(f):
+		return w.WriteString("NaN")
+	case math.IsInf(f, +1):
+		return w.WriteString("+Inf")
+	case math.IsInf(f, -1):
+		return w.WriteString("-Inf")
+	default:
+		bp := numBufPool.Get().(*[]byte)
+		*bp = strconv.AppendFloat((*bp)[:0], f, 'g', -1, 64)
+		if !bytes.ContainsAny(*bp, "e.") {
+			*bp = append(*bp, '.', '0')
+		}
+		written, err := w.Write(*bp)
+		numBufPool.Put(bp)
+		return written, err
+	}
+}
+
+// writeUint is like writeInt just for uint64.
+func writeUint(w enhancedWriter, u uint64) (int, error) {
+	bp := numBufPool.Get().(*[]byte)
+	*bp = strconv.AppendUint((*bp)[:0], u, 10)
+	written, err := w.Write(*bp)
+	numBufPool.Put(bp)
+	return written, err
+}

vendor/github.com/prometheus/common/expfmt/text_create.go

@@ -423,9 +423,8 @@ var (
 func writeEscapedString(w enhancedWriter, v string, includeDoubleQuote bool) (int, error) {
 	if includeDoubleQuote {
 		return quotedEscaper.WriteString(w, v)
-	} else {
-		return escaper.WriteString(w, v)
 	}
+	return escaper.WriteString(w, v)
 }
 
 // writeFloat is equivalent to fmt.Fprint with a float64 argument but hardcodes

vendor/github.com/prometheus/common/go.mod

@@ -11,12 +11,12 @@ require (
 	github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223
 	github.com/pkg/errors v0.8.1
 	github.com/prometheus/client_golang v1.0.0
-	github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90
+	github.com/prometheus/client_model v0.2.0
 	github.com/sirupsen/logrus v1.4.2
 	golang.org/x/net v0.0.0-20190613194153-d28f0bde5980 // indirect
 	golang.org/x/sys v0.0.0-20190422165155-953cdadca894
 	gopkg.in/alecthomas/kingpin.v2 v2.2.6
-	gopkg.in/yaml.v2 v2.2.2
+	gopkg.in/yaml.v2 v2.2.4
 )
 
 go 1.11

vendor/github.com/prometheus/procfs/crypto.go

@@ -14,10 +14,10 @@
 package procfs
 
 import (
+	"bufio"
 	"bytes"
 	"fmt"
-	"io/ioutil"
-	"strconv"
+	"io"
 	"strings"
 
 	"github.com/prometheus/procfs/internal/util"
@@ -52,80 +52,102 @@ type Crypto struct {
 // structs containing the relevant info.  More information available here:
 // https://kernel.readthedocs.io/en/sphinx-samples/crypto-API.html
 func (fs FS) Crypto() ([]Crypto, error) {
-	data, err := ioutil.ReadFile(fs.proc.Path("crypto"))
+	path := fs.proc.Path("crypto")
+	b, err := util.ReadFileNoStat(path)
 	if err != nil {
-		return nil, fmt.Errorf("error parsing crypto %s: %s", fs.proc.Path("crypto"), err)
+		return nil, fmt.Errorf("error reading crypto %s: %s", path, err)
 	}
-	crypto, err := parseCrypto(data)
+
+	crypto, err := parseCrypto(bytes.NewReader(b))
 	if err != nil {
-		return nil, fmt.Errorf("error parsing crypto %s: %s", fs.proc.Path("crypto"), err)
+		return nil, fmt.Errorf("error parsing crypto %s: %s", path, err)
 	}
+
 	return crypto, nil
 }
 
-func parseCrypto(cryptoData []byte) ([]Crypto, error) {
-	crypto := []Crypto{}
-
-	cryptoBlocks := bytes.Split(cryptoData, []byte("\n\n"))
-
-	for _, block := range cryptoBlocks {
-		var newCryptoElem Crypto
-
-		lines := strings.Split(string(block), "\n")
-		for _, line := range lines {
-			if strings.TrimSpace(line) == "" || line[0] == ' ' {
-				continue
-			}
-			fields := strings.Split(line, ":")
-			key := strings.TrimSpace(fields[0])
-			value := strings.TrimSpace(fields[1])
-			vp := util.NewValueParser(value)
-
-			switch strings.TrimSpace(key) {
-			case "async":
-				b, err := strconv.ParseBool(value)
-				if err == nil {
-					newCryptoElem.Async = b
-				}
-			case "blocksize":
-				newCryptoElem.Blocksize = vp.PUInt64()
-			case "chunksize":
-				newCryptoElem.Chunksize = vp.PUInt64()
-			case "digestsize":
-				newCryptoElem.Digestsize = vp.PUInt64()
-			case "driver":
-				newCryptoElem.Driver = value
-			case "geniv":
-				newCryptoElem.Geniv = value
-			case "internal":
-				newCryptoElem.Internal = value
-			case "ivsize":
-				newCryptoElem.Ivsize = vp.PUInt64()
-			case "maxauthsize":
-				newCryptoElem.Maxauthsize = vp.PUInt64()
-			case "max keysize":
-				newCryptoElem.MaxKeysize = vp.PUInt64()
-			case "min keysize":
-				newCryptoElem.MinKeysize = vp.PUInt64()
-			case "module":
-				newCryptoElem.Module = value
-			case "name":
-				newCryptoElem.Name = value
-			case "priority":
-				newCryptoElem.Priority = vp.PInt64()
-			case "refcnt":
-				newCryptoElem.Refcnt = vp.PInt64()
-			case "seedsize":
-				newCryptoElem.Seedsize = vp.PUInt64()
-			case "selftest":
-				newCryptoElem.Selftest = value
-			case "type":
-				newCryptoElem.Type = value
-			case "walksize":
-				newCryptoElem.Walksize = vp.PUInt64()
-			}
+// parseCrypto parses a /proc/crypto stream into Crypto elements.
+func parseCrypto(r io.Reader) ([]Crypto, error) {
+	var out []Crypto
+
+	s := bufio.NewScanner(r)
+	for s.Scan() {
+		text := s.Text()
+		switch {
+		case strings.HasPrefix(text, "name"):
+			// Each crypto element begins with its name.
+			out = append(out, Crypto{})
+		case text == "":
+			continue
+		}
+
+		kv := strings.Split(text, ":")
+		if len(kv) != 2 {
+			return nil, fmt.Errorf("malformed crypto line: %q", text)
+		}
+
+		k := strings.TrimSpace(kv[0])
+		v := strings.TrimSpace(kv[1])
+
+		// Parse the key/value pair into the currently focused element.
+		c := &out[len(out)-1]
+		if err := c.parseKV(k, v); err != nil {
+			return nil, err
 		}
-		crypto = append(crypto, newCryptoElem)
 	}
-	return crypto, nil
+
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+
+	return out, nil
+}
+
+// parseKV parses a key/value pair into the appropriate field of c.
+func (c *Crypto) parseKV(k, v string) error {
+	vp := util.NewValueParser(v)
+
+	switch k {
+	case "async":
+		// Interpret literal yes as true.
+		c.Async = v == "yes"
+	case "blocksize":
+		c.Blocksize = vp.PUInt64()
+	case "chunksize":
+		c.Chunksize = vp.PUInt64()
+	case "digestsize":
+		c.Digestsize = vp.PUInt64()
+	case "driver":
+		c.Driver = v
+	case "geniv":
+		c.Geniv = v
+	case "internal":
+		c.Internal = v
+	case "ivsize":
+		c.Ivsize = vp.PUInt64()
+	case "maxauthsize":
+		c.Maxauthsize = vp.PUInt64()
+	case "max keysize":
+		c.MaxKeysize = vp.PUInt64()
+	case "min keysize":
+		c.MinKeysize = vp.PUInt64()
+	case "module":
+		c.Module = v
+	case "name":
+		c.Name = v
+	case "priority":
+		c.Priority = vp.PInt64()
+	case "refcnt":
+		c.Refcnt = vp.PInt64()
+	case "seedsize":
+		c.Seedsize = vp.PUInt64()
+	case "selftest":
+		c.Selftest = v
+	case "type":
+		c.Type = v
+	case "walksize":
+		c.Walksize = vp.PUInt64()
+	}
+
+	return vp.Err()
 }

vendor/github.com/prometheus/procfs/go.mod

@@ -5,4 +5,5 @@ go 1.12
 require (
 	github.com/google/go-cmp v0.3.1
 	golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e
+	golang.org/x/sys v0.0.0-20200106162015-b016eb3dc98e
 )

vendor/github.com/prometheus/procfs/loadavg.go

@@ -0,0 +1,62 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package procfs
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
+)
+
+// LoadAvg represents an entry in /proc/loadavg
+type LoadAvg struct {
+	Load1  float64
+	Load5  float64
+	Load15 float64
+}
+
+// LoadAvg returns loadavg from /proc.
+func (fs FS) LoadAvg() (*LoadAvg, error) {
+	path := fs.proc.Path("loadavg")
+
+	data, err := util.ReadFileNoStat(path)
+	if err != nil {
+		return nil, err
+	}
+	return parseLoad(data)
+}
+
+// Parse /proc loadavg and return 1m, 5m and 15m.
+func parseLoad(loadavgBytes []byte) (*LoadAvg, error) {
+	loads := make([]float64, 3)
+	parts := strings.Fields(string(loadavgBytes))
+	if len(parts) < 3 {
+		return nil, fmt.Errorf("malformed loadavg line: too few fields in loadavg string: %s", string(loadavgBytes))
+	}
+
+	var err error
+	for i, load := range parts[0:3] {
+		loads[i], err = strconv.ParseFloat(load, 64)
+		if err != nil {
+			return nil, fmt.Errorf("could not parse load '%s': %s", load, err)
+		}
+	}
+	return &LoadAvg{
+		Load1:  loads[0],
+		Load5:  loads[1],
+		Load15: loads[2],
+	}, nil
+}

vendor/github.com/prometheus/procfs/mountinfo.go

@@ -29,10 +29,10 @@ import (
 // is described in the following man page.
 // http://man7.org/linux/man-pages/man5/proc.5.html
 type MountInfo struct {
-	// Unique Id for the mount
-	MountId int
-	// The Id of the parent mount
-	ParentId int
+	// Unique ID for the mount
+	MountID int
+	// The ID of the parent mount
+	ParentID int
 	// The value of `st_dev` for the files on this FS
 	MajorMinorVer string
 	// The pathname of the directory in the FS that forms
@@ -96,11 +96,11 @@ func parseMountInfoString(mountString string) (*MountInfo, error) {
 		SuperOptions:   mountOptionsParser(mountInfo[mountInfoLength-1]),
 	}
 
-	mount.MountId, err = strconv.Atoi(mountInfo[0])
+	mount.MountID, err = strconv.Atoi(mountInfo[0])
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse mount ID")
 	}
-	mount.ParentId, err = strconv.Atoi(mountInfo[1])
+	mount.ParentID, err = strconv.Atoi(mountInfo[1])
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse parent ID")
 	}

vendor/github.com/prometheus/procfs/net_conntrackstat.go

@@ -0,0 +1,153 @@
+// Copyright 2020 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package procfs
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
+)
+
+// A ConntrackStatEntry represents one line from net/stat/nf_conntrack
+// and contains netfilter conntrack statistics at one CPU core
+type ConntrackStatEntry struct {
+	Entries       uint64
+	Found         uint64
+	Invalid       uint64
+	Ignore        uint64
+	Insert        uint64
+	InsertFailed  uint64
+	Drop          uint64
+	EarlyDrop     uint64
+	SearchRestart uint64
+}
+
+// Retrieves netfilter's conntrack statistics, split by CPU cores
+func (fs FS) ConntrackStat() ([]ConntrackStatEntry, error) {
+	return readConntrackStat(fs.proc.Path("net", "stat", "nf_conntrack"))
+}
+
+// Parses a slice of ConntrackStatEntries from the given filepath
+func readConntrackStat(path string) ([]ConntrackStatEntry, error) {
+	// This file is small and can be read with one syscall.
+	b, err := util.ReadFileNoStat(path)
+	if err != nil {
+		// Do not wrap this error so the caller can detect os.IsNotExist and
+		// similar conditions.
+		return nil, err
+	}
+
+	stat, err := parseConntrackStat(bytes.NewReader(b))
+	if err != nil {
+		return nil, fmt.Errorf("failed to read conntrack stats from %q: %v", path, err)
+	}
+
+	return stat, nil
+}
+
+// Reads the contents of a conntrack statistics file and parses a slice of ConntrackStatEntries
+func parseConntrackStat(r io.Reader) ([]ConntrackStatEntry, error) {
+	var entries []ConntrackStatEntry
+
+	scanner := bufio.NewScanner(r)
+	scanner.Scan()
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		conntrackEntry, err := parseConntrackStatEntry(fields)
+		if err != nil {
+			return nil, err
+		}
+		entries = append(entries, *conntrackEntry)
+	}
+
+	return entries, nil
+}
+
+// Parses a ConntrackStatEntry from given array of fields
+func parseConntrackStatEntry(fields []string) (*ConntrackStatEntry, error) {
+	if len(fields) != 17 {
+		return nil, fmt.Errorf("invalid conntrackstat entry, missing fields")
+	}
+	entry := &ConntrackStatEntry{}
+
+	entries, err := parseConntrackStatField(fields[0])
+	if err != nil {
+		return nil, err
+	}
+	entry.Entries = entries
+
+	found, err := parseConntrackStatField(fields[2])
+	if err != nil {
+		return nil, err
+	}
+	entry.Found = found
+
+	invalid, err := parseConntrackStatField(fields[4])
+	if err != nil {
+		return nil, err
+	}
+	entry.Invalid = invalid
+
+	ignore, err := parseConntrackStatField(fields[5])
+	if err != nil {
+		return nil, err
+	}
+	entry.Ignore = ignore
+
+	insert, err := parseConntrackStatField(fields[8])
+	if err != nil {
+		return nil, err
+	}
+	entry.Insert = insert
+
+	insertFailed, err := parseConntrackStatField(fields[9])
+	if err != nil {
+		return nil, err
+	}
+	entry.InsertFailed = insertFailed
+
+	drop, err := parseConntrackStatField(fields[10])
+	if err != nil {
+		return nil, err
+	}
+	entry.Drop = drop
+
+	earlyDrop, err := parseConntrackStatField(fields[11])
+	if err != nil {
+		return nil, err
+	}
+	entry.EarlyDrop = earlyDrop
+
+	searchRestart, err := parseConntrackStatField(fields[16])
+	if err != nil {
+		return nil, err
+	}
+	entry.SearchRestart = searchRestart
+
+	return entry, nil
+}
+
+// Parses a uint64 from given hex in string
+func parseConntrackStatField(field string) (uint64, error) {
+	val, err := strconv.ParseUint(field, 16, 64)
+	if err != nil {
+		return 0, fmt.Errorf("couldn't parse \"%s\" field: %s", field, err)
+	}
+	return val, err
+}

vendor/github.com/prometheus/procfs/net_softnet.go

@@ -14,78 +14,89 @@
 package procfs
 
 import (
+	"bufio"
+	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"strconv"
 	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
 )
 
 // For the proc file format details,
-// see https://elixir.bootlin.com/linux/v4.17/source/net/core/net-procfs.c#L162
+// See:
+// * Linux 2.6.23 https://elixir.bootlin.com/linux/v2.6.23/source/net/core/dev.c#L2343
+// * Linux 4.17 https://elixir.bootlin.com/linux/v4.17/source/net/core/net-procfs.c#L162
 // and https://elixir.bootlin.com/linux/v4.17/source/include/linux/netdevice.h#L2810.
 
-// SoftnetEntry contains a single row of data from /proc/net/softnet_stat
-type SoftnetEntry struct {
+// SoftnetStat contains a single row of data from /proc/net/softnet_stat
+type SoftnetStat struct {
 	// Number of processed packets
-	Processed uint
+	Processed uint32
 	// Number of dropped packets
-	Dropped uint
+	Dropped uint32
 	// Number of times processing packets ran out of quota
-	TimeSqueezed uint
+	TimeSqueezed uint32
 }
 
-// GatherSoftnetStats reads /proc/net/softnet_stat, parse the relevant columns,
-// and then return a slice of SoftnetEntry's.
-func (fs FS) GatherSoftnetStats() ([]SoftnetEntry, error) {
-	data, err := ioutil.ReadFile(fs.proc.Path("net/softnet_stat"))
+var softNetProcFile = "net/softnet_stat"
+
+// NetSoftnetStat reads data from /proc/net/softnet_stat.
+func (fs FS) NetSoftnetStat() ([]SoftnetStat, error) {
+	b, err := util.ReadFileNoStat(fs.proc.Path(softNetProcFile))
+	if err != nil {
+		return nil, err
+	}
+
+	entries, err := parseSoftnet(bytes.NewReader(b))
 	if err != nil {
-		return nil, fmt.Errorf("error reading softnet %s: %s", fs.proc.Path("net/softnet_stat"), err)
+		return nil, fmt.Errorf("failed to parse /proc/net/softnet_stat: %v", err)
 	}
 
-	return parseSoftnetEntries(data)
+	return entries, nil
 }
 
-func parseSoftnetEntries(data []byte) ([]SoftnetEntry, error) {
-	lines := strings.Split(string(data), "\n")
-	entries := make([]SoftnetEntry, 0)
-	var err error
-	const (
-		expectedColumns = 11
-	)
-	for _, line := range lines {
-		columns := strings.Fields(line)
+func parseSoftnet(r io.Reader) ([]SoftnetStat, error) {
+	const minColumns = 9
+
+	s := bufio.NewScanner(r)
+
+	var stats []SoftnetStat
+	for s.Scan() {
+		columns := strings.Fields(s.Text())
 		width := len(columns)
-		if width == 0 {
-			continue
-		}
-		if width != expectedColumns {
-			return []SoftnetEntry{}, fmt.Errorf("%d columns were detected, but %d were expected", width, expectedColumns)
+
+		if width < minColumns {
+			return nil, fmt.Errorf("%d columns were detected, but at least %d were expected", width, minColumns)
 		}
-		var entry SoftnetEntry
-		if entry, err = parseSoftnetEntry(columns); err != nil {
-			return []SoftnetEntry{}, err
+
+		// We only parse the first three columns at the moment.
+		us, err := parseHexUint32s(columns[0:3])
+		if err != nil {
+			return nil, err
 		}
-		entries = append(entries, entry)
+
+		stats = append(stats, SoftnetStat{
+			Processed:    us[0],
+			Dropped:      us[1],
+			TimeSqueezed: us[2],
+		})
 	}
 
-	return entries, nil
+	return stats, nil
 }
 
-func parseSoftnetEntry(columns []string) (SoftnetEntry, error) {
-	var err error
-	var processed, dropped, timeSqueezed uint64
-	if processed, err = strconv.ParseUint(columns[0], 16, 32); err != nil {
-		return SoftnetEntry{}, fmt.Errorf("Unable to parse column 0: %s", err)
-	}
-	if dropped, err = strconv.ParseUint(columns[1], 16, 32); err != nil {
-		return SoftnetEntry{}, fmt.Errorf("Unable to parse column 1: %s", err)
-	}
-	if timeSqueezed, err = strconv.ParseUint(columns[2], 16, 32); err != nil {
-		return SoftnetEntry{}, fmt.Errorf("Unable to parse column 2: %s", err)
+func parseHexUint32s(ss []string) ([]uint32, error) {
+	us := make([]uint32, 0, len(ss))
+	for _, s := range ss {
+		u, err := strconv.ParseUint(s, 16, 32)
+		if err != nil {
+			return nil, err
+		}
+
+		us = append(us, uint32(u))
 	}
-	return SoftnetEntry{
-		Processed:    uint(processed),
-		Dropped:      uint(dropped),
-		TimeSqueezed: uint(timeSqueezed),
-	}, nil
+
+	return us, nil
 }

vendor/github.com/prometheus/procfs/net_udp.go

@@ -0,0 +1,229 @@
+// Copyright 2020 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package procfs
+
+import (
+	"bufio"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	// readLimit is used by io.LimitReader while reading the content of the
+	// /proc/net/udp{,6} files. The number of lines inside such a file is dynamic
+	// as each line represents a single used socket.
+	// In theory, the number of available sockets is 65535 (2^16 - 1) per IP.
+	// With e.g. 150 Byte per line and the maximum number of 65535,
+	// the reader needs to handle 150 Byte * 65535 =~ 10 MB for a single IP.
+	readLimit = 4294967296 // Byte -> 4 GiB
+)
+
+type (
+	// NetUDP represents the contents of /proc/net/udp{,6} file without the header.
+	NetUDP []*netUDPLine
+
+	// NetUDPSummary provides already computed values like the total queue lengths or
+	// the total number of used sockets. In contrast to NetUDP it does not collect
+	// the parsed lines into a slice.
+	NetUDPSummary struct {
+		// TxQueueLength shows the total queue length of all parsed tx_queue lengths.
+		TxQueueLength uint64
+		// RxQueueLength shows the total queue length of all parsed rx_queue lengths.
+		RxQueueLength uint64
+		// UsedSockets shows the total number of parsed lines representing the
+		// number of used sockets.
+		UsedSockets uint64
+	}
+
+	// netUDPLine represents the fields parsed from a single line
+	// in /proc/net/udp{,6}. Fields which are not used by UDP are skipped.
+	// For the proc file format details, see https://linux.die.net/man/5/proc.
+	netUDPLine struct {
+		Sl        uint64
+		LocalAddr net.IP
+		LocalPort uint64
+		RemAddr   net.IP
+		RemPort   uint64
+		St        uint64
+		TxQueue   uint64
+		RxQueue   uint64
+		UID       uint64
+	}
+)
+
+// NetUDP returns the IPv4 kernel/networking statistics for UDP datagrams
+// read from /proc/net/udp.
+func (fs FS) NetUDP() (NetUDP, error) {
+	return newNetUDP(fs.proc.Path("net/udp"))
+}
+
+// NetUDP6 returns the IPv6 kernel/networking statistics for UDP datagrams
+// read from /proc/net/udp6.
+func (fs FS) NetUDP6() (NetUDP, error) {
+	return newNetUDP(fs.proc.Path("net/udp6"))
+}
+
+// NetUDPSummary returns already computed statistics like the total queue lengths
+// for UDP datagrams read from /proc/net/udp.
+func (fs FS) NetUDPSummary() (*NetUDPSummary, error) {
+	return newNetUDPSummary(fs.proc.Path("net/udp"))
+}
+
+// NetUDP6Summary returns already computed statistics like the total queue lengths
+// for UDP datagrams read from /proc/net/udp6.
+func (fs FS) NetUDP6Summary() (*NetUDPSummary, error) {
+	return newNetUDPSummary(fs.proc.Path("net/udp6"))
+}
+
+// newNetUDP creates a new NetUDP{,6} from the contents of the given file.
+func newNetUDP(file string) (NetUDP, error) {
+	f, err := os.Open(file)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	netUDP := NetUDP{}
+
+	lr := io.LimitReader(f, readLimit)
+	s := bufio.NewScanner(lr)
+	s.Scan() // skip first line with headers
+	for s.Scan() {
+		fields := strings.Fields(s.Text())
+		line, err := parseNetUDPLine(fields)
+		if err != nil {
+			return nil, err
+		}
+		netUDP = append(netUDP, line)
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+	return netUDP, nil
+}
+
+// newNetUDPSummary creates a new NetUDP{,6} from the contents of the given file.
+func newNetUDPSummary(file string) (*NetUDPSummary, error) {
+	f, err := os.Open(file)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	netUDPSummary := &NetUDPSummary{}
+
+	lr := io.LimitReader(f, readLimit)
+	s := bufio.NewScanner(lr)
+	s.Scan() // skip first line with headers
+	for s.Scan() {
+		fields := strings.Fields(s.Text())
+		line, err := parseNetUDPLine(fields)
+		if err != nil {
+			return nil, err
+		}
+		netUDPSummary.TxQueueLength += line.TxQueue
+		netUDPSummary.RxQueueLength += line.RxQueue
+		netUDPSummary.UsedSockets++
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+	return netUDPSummary, nil
+}
+
+// parseNetUDPLine parses a single line, represented by a list of fields.
+func parseNetUDPLine(fields []string) (*netUDPLine, error) {
+	line := &netUDPLine{}
+	if len(fields) < 8 {
+		return nil, fmt.Errorf(
+			"cannot parse net udp socket line as it has less then 8 columns: %s",
+			strings.Join(fields, " "),
+		)
+	}
+	var err error // parse error
+
+	// sl
+	s := strings.Split(fields[0], ":")
+	if len(s) != 2 {
+		return nil, fmt.Errorf(
+			"cannot parse sl field in udp socket line: %s", fields[0])
+	}
+
+	if line.Sl, err = strconv.ParseUint(s[0], 0, 64); err != nil {
+		return nil, fmt.Errorf("cannot parse sl value in udp socket line: %s", err)
+	}
+	// local_address
+	l := strings.Split(fields[1], ":")
+	if len(l) != 2 {
+		return nil, fmt.Errorf(
+			"cannot parse local_address field in udp socket line: %s", fields[1])
+	}
+	if line.LocalAddr, err = hex.DecodeString(l[0]); err != nil {
+		return nil, fmt.Errorf(
+			"cannot parse local_address value in udp socket line: %s", err)
+	}
+	if line.LocalPort, err = strconv.ParseUint(l[1], 16, 64); err != nil {
+		return nil, fmt.Errorf(
+			"cannot parse local_address port value in udp socket line: %s", err)
+	}
+
+	// remote_address
+	r := strings.Split(fields[2], ":")
+	if len(r) != 2 {
+		return nil, fmt.Errorf(
+			"cannot parse rem_address field in udp socket line: %s", fields[1])
+	}
+	if line.RemAddr, err = hex.DecodeString(r[0]); err != nil {
+		return nil, fmt.Errorf(
+			"cannot parse rem_address value in udp socket line: %s", err)
+	}
+	if line.RemPort, err = strconv.ParseUint(r[1], 16, 64); err != nil {
+		return nil, fmt.Errorf(
+			"cannot parse rem_address port value in udp socket line: %s", err)
+	}
+
+	// st
+	if line.St, err = strconv.ParseUint(fields[3], 16, 64); err != nil {
+		return nil, fmt.Errorf(
+			"cannot parse st value in udp socket line: %s", err)
+	}
+
+	// tx_queue and rx_queue
+	q := strings.Split(fields[4], ":")
+	if len(q) != 2 {
+		return nil, fmt.Errorf(
+			"cannot parse tx/rx queues in udp socket line as it has a missing colon: %s",
+			fields[4],
+		)
+	}
+	if line.TxQueue, err = strconv.ParseUint(q[0], 16, 64); err != nil {
+		return nil, fmt.Errorf("cannot parse tx_queue value in udp socket line: %s", err)
+	}
+	if line.RxQueue, err = strconv.ParseUint(q[1], 16, 64); err != nil {
+		return nil, fmt.Errorf("cannot parse rx_queue value in udp socket line: %s", err)
+	}
+
+	// uid
+	if line.UID, err = strconv.ParseUint(fields[7], 0, 64); err != nil {
+		return nil, fmt.Errorf(
+			"cannot parse uid value in udp socket line: %s", err)
+	}
+
+	return line, nil
+}

vendor/github.com/prometheus/procfs/net_unix.go

@@ -15,7 +15,6 @@ package procfs
 
 import (
 	"bufio"
-	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -27,25 +26,15 @@ import (
 // see https://elixir.bootlin.com/linux/v4.17/source/net/unix/af_unix.c#L2815
 // and https://elixir.bootlin.com/linux/latest/source/include/uapi/linux/net.h#L48.
 
-const (
-	netUnixKernelPtrIdx = iota
-	netUnixRefCountIdx
-	_
-	netUnixFlagsIdx
-	netUnixTypeIdx
-	netUnixStateIdx
-	netUnixInodeIdx
-
-	// Inode and Path are optional.
-	netUnixStaticFieldsCnt = 6
-)
-
+// Constants for the various /proc/net/unix enumerations.
+// TODO: match against x/sys/unix or similar?
 const (
 	netUnixTypeStream    = 1
 	netUnixTypeDgram     = 2
 	netUnixTypeSeqpacket = 5
 
-	netUnixFlagListen = 1 << 16
+	netUnixFlagDefault = 0
+	netUnixFlagListen  = 1 << 16
 
 	netUnixStateUnconnected  = 1
 	netUnixStateConnecting   = 2
@@ -53,129 +42,127 @@ const (
 	netUnixStateDisconnected = 4
 )
 
-var errInvalidKernelPtrFmt = errors.New("Invalid Num(the kernel table slot number) format")
+// NetUNIXType is the type of the type field.
+type NetUNIXType uint64
 
-// NetUnixType is the type of the type field.
-type NetUnixType uint64
+// NetUNIXFlags is the type of the flags field.
+type NetUNIXFlags uint64
 
-// NetUnixFlags is the type of the flags field.
-type NetUnixFlags uint64
+// NetUNIXState is the type of the state field.
+type NetUNIXState uint64
 
-// NetUnixState is the type of the state field.
-type NetUnixState uint64
-
-// NetUnixLine represents a line of /proc/net/unix.
-type NetUnixLine struct {
+// NetUNIXLine represents a line of /proc/net/unix.
+type NetUNIXLine struct {
 	KernelPtr string
 	RefCount  uint64
 	Protocol  uint64
-	Flags     NetUnixFlags
-	Type      NetUnixType
-	State     NetUnixState
+	Flags     NetUNIXFlags
+	Type      NetUNIXType
+	State     NetUNIXState
 	Inode     uint64
 	Path      string
 }
 
-// NetUnix holds the data read from /proc/net/unix.
-type NetUnix struct {
-	Rows []*NetUnixLine
+// NetUNIX holds the data read from /proc/net/unix.
+type NetUNIX struct {
+	Rows []*NetUNIXLine
 }
 
-// NewNetUnix returns data read from /proc/net/unix.
-func NewNetUnix() (*NetUnix, error) {
-	fs, err := NewFS(DefaultMountPoint)
-	if err != nil {
-		return nil, err
-	}
-
-	return fs.NewNetUnix()
+// NetUNIX returns data read from /proc/net/unix.
+func (fs FS) NetUNIX() (*NetUNIX, error) {
+	return readNetUNIX(fs.proc.Path("net/unix"))
 }
 
-// NewNetUnix returns data read from /proc/net/unix.
-func (fs FS) NewNetUnix() (*NetUnix, error) {
-	return NewNetUnixByPath(fs.proc.Path("net/unix"))
-}
-
-// NewNetUnixByPath returns data read from /proc/net/unix by file path.
-// It might returns an error with partial parsed data, if an error occur after some data parsed.
-func NewNetUnixByPath(path string) (*NetUnix, error) {
-	f, err := os.Open(path)
+// readNetUNIX reads data in /proc/net/unix format from the specified file.
+func readNetUNIX(file string) (*NetUNIX, error) {
+	// This file could be quite large and a streaming read is desirable versus
+	// reading the entire contents at once.
+	f, err := os.Open(file)
 	if err != nil {
 		return nil, err
 	}
 	defer f.Close()
-	return NewNetUnixByReader(f)
+
+	return parseNetUNIX(f)
 }
 
-// NewNetUnixByReader returns data read from /proc/net/unix by a reader.
-// It might returns an error with partial parsed data, if an error occur after some data parsed.
-func NewNetUnixByReader(reader io.Reader) (*NetUnix, error) {
-	nu := &NetUnix{
-		Rows: make([]*NetUnixLine, 0, 32),
-	}
-	scanner := bufio.NewScanner(reader)
-	// Omit the header line.
-	scanner.Scan()
-	header := scanner.Text()
+// parseNetUNIX creates a NetUnix structure from the incoming stream.
+func parseNetUNIX(r io.Reader) (*NetUNIX, error) {
+	// Begin scanning by checking for the existence of Inode.
+	s := bufio.NewScanner(r)
+	s.Scan()
+
 	// From the man page of proc(5), it does not contain an Inode field,
-	// but in actually it exists.
-	// This code works for both cases.
-	hasInode := strings.Contains(header, "Inode")
+	// but in actually it exists. This code works for both cases.
+	hasInode := strings.Contains(s.Text(), "Inode")
 
-	minFieldsCnt := netUnixStaticFieldsCnt
+	// Expect a minimum number of fields, but Inode and Path are optional:
+	// Num       RefCount Protocol Flags    Type St Inode Path
+	minFields := 6
 	if hasInode {
-		minFieldsCnt++
+		minFields++
 	}
-	for scanner.Scan() {
-		line := scanner.Text()
-		item, err := nu.parseLine(line, hasInode, minFieldsCnt)
+
+	var nu NetUNIX
+	for s.Scan() {
+		line := s.Text()
+		item, err := nu.parseLine(line, hasInode, minFields)
 		if err != nil {
-			return nu, err
+			return nil, fmt.Errorf("failed to parse /proc/net/unix data %q: %v", line, err)
 		}
+
 		nu.Rows = append(nu.Rows, item)
 	}
 
-	return nu, scanner.Err()
+	if err := s.Err(); err != nil {
+		return nil, fmt.Errorf("failed to scan /proc/net/unix data: %v", err)
+	}
+
+	return &nu, nil
 }
 
-func (u *NetUnix) parseLine(line string, hasInode bool, minFieldsCnt int) (*NetUnixLine, error) {
+func (u *NetUNIX) parseLine(line string, hasInode bool, min int) (*NetUNIXLine, error) {
 	fields := strings.Fields(line)
-	fieldsLen := len(fields)
-	if fieldsLen < minFieldsCnt {
-		return nil, fmt.Errorf(
-			"Parse Unix domain failed: expect at least %d fields but got %d",
-			minFieldsCnt, fieldsLen)
-	}
-	kernelPtr, err := u.parseKernelPtr(fields[netUnixKernelPtrIdx])
-	if err != nil {
-		return nil, fmt.Errorf("Parse Unix domain num(%s) failed: %s", fields[netUnixKernelPtrIdx], err)
+
+	l := len(fields)
+	if l < min {
+		return nil, fmt.Errorf("expected at least %d fields but got %d", min, l)
 	}
-	users, err := u.parseUsers(fields[netUnixRefCountIdx])
+
+	// Field offsets are as follows:
+	// Num       RefCount Protocol Flags    Type St Inode Path
+
+	kernelPtr := strings.TrimSuffix(fields[0], ":")
+
+	users, err := u.parseUsers(fields[1])
 	if err != nil {
-		return nil, fmt.Errorf("Parse Unix domain ref count(%s) failed: %s", fields[netUnixRefCountIdx], err)
+		return nil, fmt.Errorf("failed to parse ref count(%s): %v", fields[1], err)
 	}
-	flags, err := u.parseFlags(fields[netUnixFlagsIdx])
+
+	flags, err := u.parseFlags(fields[3])
 	if err != nil {
-		return nil, fmt.Errorf("Parse Unix domain flags(%s) failed: %s", fields[netUnixFlagsIdx], err)
+		return nil, fmt.Errorf("failed to parse flags(%s): %v", fields[3], err)
 	}
-	typ, err := u.parseType(fields[netUnixTypeIdx])
+
+	typ, err := u.parseType(fields[4])
 	if err != nil {
-		return nil, fmt.Errorf("Parse Unix domain type(%s) failed: %s", fields[netUnixTypeIdx], err)
+		return nil, fmt.Errorf("failed to parse type(%s): %v", fields[4], err)
 	}
-	state, err := u.parseState(fields[netUnixStateIdx])
+
+	state, err := u.parseState(fields[5])
 	if err != nil {
-		return nil, fmt.Errorf("Parse Unix domain state(%s) failed: %s", fields[netUnixStateIdx], err)
+		return nil, fmt.Errorf("failed to parse state(%s): %v", fields[5], err)
 	}
+
 	var inode uint64
 	if hasInode {
-		inodeStr := fields[netUnixInodeIdx]
-		inode, err = u.parseInode(inodeStr)
+		inode, err = u.parseInode(fields[6])
 		if err != nil {
-			return nil, fmt.Errorf("Parse Unix domain inode(%s) failed: %s", inodeStr, err)
+			return nil, fmt.Errorf("failed to parse inode(%s): %v", fields[6], err)
 		}
 	}
 
-	nuLine := &NetUnixLine{
+	n := &NetUNIXLine{
 		KernelPtr: kernelPtr,
 		RefCount:  users,
 		Type:      typ,
@@ -185,57 +172,56 @@ func (u *NetUnix) parseLine(line string, hasInode bool, minFieldsCnt int) (*NetU
 	}
 
 	// Path field is optional.
-	if fieldsLen > minFieldsCnt {
-		pathIdx := netUnixInodeIdx + 1
+	if l > min {
+		// Path occurs at either index 6 or 7 depending on whether inode is
+		// already present.
+		pathIdx := 7
 		if !hasInode {
 			pathIdx--
 		}
-		nuLine.Path = fields[pathIdx]
-	}
-
-	return nuLine, nil
-}
 
-func (u NetUnix) parseKernelPtr(str string) (string, error) {
-	if !strings.HasSuffix(str, ":") {
-		return "", errInvalidKernelPtrFmt
+		n.Path = fields[pathIdx]
 	}
-	return str[:len(str)-1], nil
+
+	return n, nil
 }
 
-func (u NetUnix) parseUsers(hexStr string) (uint64, error) {
-	return strconv.ParseUint(hexStr, 16, 32)
+func (u NetUNIX) parseUsers(s string) (uint64, error) {
+	return strconv.ParseUint(s, 16, 32)
 }
 
-func (u NetUnix) parseType(hexStr string) (NetUnixType, error) {
-	typ, err := strconv.ParseUint(hexStr, 16, 16)
+func (u NetUNIX) parseType(s string) (NetUNIXType, error) {
+	typ, err := strconv.ParseUint(s, 16, 16)
 	if err != nil {
 		return 0, err
 	}
-	return NetUnixType(typ), nil
+
+	return NetUNIXType(typ), nil
 }
 
-func (u NetUnix) parseFlags(hexStr string) (NetUnixFlags, error) {
-	flags, err := strconv.ParseUint(hexStr, 16, 32)
+func (u NetUNIX) parseFlags(s string) (NetUNIXFlags, error) {
+	flags, err := strconv.ParseUint(s, 16, 32)
 	if err != nil {
 		return 0, err
 	}
-	return NetUnixFlags(flags), nil
+
+	return NetUNIXFlags(flags), nil
 }
 
-func (u NetUnix) parseState(hexStr string) (NetUnixState, error) {
-	st, err := strconv.ParseInt(hexStr, 16, 8)
+func (u NetUNIX) parseState(s string) (NetUNIXState, error) {
+	st, err := strconv.ParseInt(s, 16, 8)
 	if err != nil {
 		return 0, err
 	}
-	return NetUnixState(st), nil
+
+	return NetUNIXState(st), nil
 }
 
-func (u NetUnix) parseInode(inodeStr string) (uint64, error) {
-	return strconv.ParseUint(inodeStr, 10, 64)
+func (u NetUNIX) parseInode(s string) (uint64, error) {
+	return strconv.ParseUint(s, 10, 64)
 }
 
-func (t NetUnixType) String() string {
+func (t NetUNIXType) String() string {
 	switch t {
 	case netUnixTypeStream:
 		return "stream"
@@ -247,7 +233,7 @@ func (t NetUnixType) String() string {
 	return "unknown"
 }
 
-func (f NetUnixFlags) String() string {
+func (f NetUNIXFlags) String() string {
 	switch f {
 	case netUnixFlagListen:
 		return "listen"
@@ -256,7 +242,7 @@ func (f NetUnixFlags) String() string {
 	}
 }
 
-func (s NetUnixState) String() string {
+func (s NetUNIXState) String() string {
 	switch s {
 	case netUnixStateUnconnected:
 		return "unconnected"

vendor/github.com/prometheus/procfs/proc_fdinfo.go

@@ -16,6 +16,7 @@ package procfs
 import (
 	"bufio"
 	"bytes"
+	"errors"
 	"regexp"
 
 	"github.com/prometheus/procfs/internal/util"
@@ -23,10 +24,11 @@ import (
 
 // Regexp variables
 var (
-	rPos     = regexp.MustCompile(`^pos:\s+(\d+)$`)
-	rFlags   = regexp.MustCompile(`^flags:\s+(\d+)$`)
-	rMntID   = regexp.MustCompile(`^mnt_id:\s+(\d+)$`)
-	rInotify = regexp.MustCompile(`^inotify`)
+	rPos          = regexp.MustCompile(`^pos:\s+(\d+)$`)
+	rFlags        = regexp.MustCompile(`^flags:\s+(\d+)$`)
+	rMntID        = regexp.MustCompile(`^mnt_id:\s+(\d+)$`)
+	rInotify      = regexp.MustCompile(`^inotify`)
+	rInotifyParts = regexp.MustCompile(`^inotify\s+wd:([0-9a-f]+)\s+ino:([0-9a-f]+)\s+sdev:([0-9a-f]+)(?:\s+mask:([0-9a-f]+))?`)
 )
 
 // ProcFDInfo contains represents file descriptor information.
@@ -96,15 +98,21 @@ type InotifyInfo struct {
 
 // InotifyInfo constructor. Only available on kernel 3.8+.
 func parseInotifyInfo(line string) (*InotifyInfo, error) {
-	r := regexp.MustCompile(`^inotify\s+wd:([0-9a-f]+)\s+ino:([0-9a-f]+)\s+sdev:([0-9a-f]+)\s+mask:([0-9a-f]+)`)
-	m := r.FindStringSubmatch(line)
-	i := &InotifyInfo{
-		WD:   m[1],
-		Ino:  m[2],
-		Sdev: m[3],
-		Mask: m[4],
+	m := rInotifyParts.FindStringSubmatch(line)
+	if len(m) >= 4 {
+		var mask string
+		if len(m) == 5 {
+			mask = m[4]
+		}
+		i := &InotifyInfo{
+			WD:   m[1],
+			Ino:  m[2],
+			Sdev: m[3],
+			Mask: mask,
+		}
+		return i, nil
 	}
-	return i, nil
+	return nil, errors.New("invalid inode entry: " + line)
 }
 
 // ProcFDInfos represents a list of ProcFDInfo structs.

vendor/github.com/prometheus/procfs/proc_maps.go

@@ -0,0 +1,208 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !windows
+
+package procfs
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+
+	"golang.org/x/sys/unix"
+)
+
+type ProcMapPermissions struct {
+	// mapping has the [R]ead flag set
+	Read bool
+	// mapping has the [W]rite flag set
+	Write bool
+	// mapping has the [X]ecutable flag set
+	Execute bool
+	// mapping has the [S]hared flag set
+	Shared bool
+	// mapping is marked as [P]rivate (copy on write)
+	Private bool
+}
+
+// ProcMap contains the process memory-mappings of the process,
+// read from /proc/[pid]/maps
+type ProcMap struct {
+	// The start address of current mapping.
+	StartAddr uintptr
+	// The end address of the current mapping
+	EndAddr uintptr
+	// The permissions for this mapping
+	Perms *ProcMapPermissions
+	// The current offset into the file/fd (e.g., shared libs)
+	Offset int64
+	// Device owner of this mapping (major:minor) in Mkdev format.
+	Dev uint64
+	// The inode of the device above
+	Inode uint64
+	// The file or psuedofile (or empty==anonymous)
+	Pathname string
+}
+
+// parseDevice parses the device token of a line and converts it to a dev_t
+// (mkdev) like structure.
+func parseDevice(s string) (uint64, error) {
+	toks := strings.Split(s, ":")
+	if len(toks) < 2 {
+		return 0, fmt.Errorf("unexpected number of fields")
+	}
+
+	major, err := strconv.ParseUint(toks[0], 16, 0)
+	if err != nil {
+		return 0, err
+	}
+
+	minor, err := strconv.ParseUint(toks[1], 16, 0)
+	if err != nil {
+		return 0, err
+	}
+
+	return unix.Mkdev(uint32(major), uint32(minor)), nil
+}
+
+// parseAddress just converts a hex-string to a uintptr
+func parseAddress(s string) (uintptr, error) {
+	a, err := strconv.ParseUint(s, 16, 0)
+	if err != nil {
+		return 0, err
+	}
+
+	return uintptr(a), nil
+}
+
+// parseAddresses parses the start-end address
+func parseAddresses(s string) (uintptr, uintptr, error) {
+	toks := strings.Split(s, "-")
+	if len(toks) < 2 {
+		return 0, 0, fmt.Errorf("invalid address")
+	}
+
+	saddr, err := parseAddress(toks[0])
+	if err != nil {
+		return 0, 0, err
+	}
+
+	eaddr, err := parseAddress(toks[1])
+	if err != nil {
+		return 0, 0, err
+	}
+
+	return saddr, eaddr, nil
+}
+
+// parsePermissions parses a token and returns any that are set.
+func parsePermissions(s string) (*ProcMapPermissions, error) {
+	if len(s) < 4 {
+		return nil, fmt.Errorf("invalid permissions token")
+	}
+
+	perms := ProcMapPermissions{}
+	for _, ch := range s {
+		switch ch {
+		case 'r':
+			perms.Read = true
+		case 'w':
+			perms.Write = true
+		case 'x':
+			perms.Execute = true
+		case 'p':
+			perms.Private = true
+		case 's':
+			perms.Shared = true
+		}
+	}
+
+	return &perms, nil
+}
+
+// parseProcMap will attempt to parse a single line within a proc/[pid]/maps
+// buffer.
+func parseProcMap(text string) (*ProcMap, error) {
+	fields := strings.Fields(text)
+	if len(fields) < 5 {
+		return nil, fmt.Errorf("truncated procmap entry")
+	}
+
+	saddr, eaddr, err := parseAddresses(fields[0])
+	if err != nil {
+		return nil, err
+	}
+
+	perms, err := parsePermissions(fields[1])
+	if err != nil {
+		return nil, err
+	}
+
+	offset, err := strconv.ParseInt(fields[2], 16, 0)
+	if err != nil {
+		return nil, err
+	}
+
+	device, err := parseDevice(fields[3])
+	if err != nil {
+		return nil, err
+	}
+
+	inode, err := strconv.ParseUint(fields[4], 10, 0)
+	if err != nil {
+		return nil, err
+	}
+
+	pathname := ""
+
+	if len(fields) >= 5 {
+		pathname = strings.Join(fields[5:], " ")
+	}
+
+	return &ProcMap{
+		StartAddr: saddr,
+		EndAddr:   eaddr,
+		Perms:     perms,
+		Offset:    offset,
+		Dev:       device,
+		Inode:     inode,
+		Pathname:  pathname,
+	}, nil
+}
+
+// ProcMaps reads from /proc/[pid]/maps to get the memory-mappings of the
+// process.
+func (p Proc) ProcMaps() ([]*ProcMap, error) {
+	file, err := os.Open(p.path("maps"))
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	maps := []*ProcMap{}
+	scan := bufio.NewScanner(file)
+
+	for scan.Scan() {
+		m, err := parseProcMap(scan.Text())
+		if err != nil {
+			return nil, err
+		}
+
+		maps = append(maps, m)
+	}
+
+	return maps, nil
+}

vendor/github.com/prometheus/procfs/proc_status.go

@@ -33,37 +33,37 @@ type ProcStatus struct {
 	TGID int
 
 	// Peak virtual memory size.
-	VmPeak uint64
+	VmPeak uint64 // nolint:golint
 	// Virtual memory size.
-	VmSize uint64
+	VmSize uint64 // nolint:golint
 	// Locked memory size.
-	VmLck uint64
+	VmLck uint64 // nolint:golint
 	// Pinned memory size.
-	VmPin uint64
+	VmPin uint64 // nolint:golint
 	// Peak resident set size.
-	VmHWM uint64
+	VmHWM uint64 // nolint:golint
 	// Resident set size (sum of RssAnnon RssFile and RssShmem).
-	VmRSS uint64
+	VmRSS uint64 // nolint:golint
 	// Size of resident anonymous memory.
-	RssAnon uint64
+	RssAnon uint64 // nolint:golint
 	// Size of resident file mappings.
-	RssFile uint64
+	RssFile uint64 // nolint:golint
 	// Size of resident shared memory.
-	RssShmem uint64
+	RssShmem uint64 // nolint:golint
 	// Size of data segments.
-	VmData uint64
+	VmData uint64 // nolint:golint
 	// Size of stack segments.
-	VmStk uint64
+	VmStk uint64 // nolint:golint
 	// Size of text segments.
-	VmExe uint64
+	VmExe uint64 // nolint:golint
 	// Shared library code size.
-	VmLib uint64
+	VmLib uint64 // nolint:golint
 	// Page table entries size.
-	VmPTE uint64
+	VmPTE uint64 // nolint:golint
 	// Size of second-level page tables.
-	VmPMD uint64
+	VmPMD uint64 // nolint:golint
 	// Swapped-out virtual memory size by anonymous private.
-	VmSwap uint64
+	VmSwap uint64 // nolint:golint
 	// Size of hugetlb memory portions
 	HugetlbPages uint64
 
@@ -71,6 +71,9 @@ type ProcStatus struct {
 	VoluntaryCtxtSwitches uint64
 	// Number of involuntary context switches.
 	NonVoluntaryCtxtSwitches uint64
+
+	// UIDs of the process (Real, effective, saved set, and filesystem UIDs (GIDs))
+	UIDs [4]string
 }
 
 // NewStatus returns the current status information of the process.
@@ -114,6 +117,8 @@ func (s *ProcStatus) fillStatus(k string, vString string, vUint uint64, vUintByt
 		s.TGID = int(vUint)
 	case "Name":
 		s.Name = vString
+	case "Uid":
+		copy(s.UIDs[:], strings.Split(vString, "\t"))
 	case "VmPeak":
 		s.VmPeak = vUintBytes
 	case "VmSize":

vendor/github.com/prometheus/procfs/swaps.go

@@ -0,0 +1,89 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package procfs
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
+)
+
+// Swap represents an entry in /proc/swaps.
+type Swap struct {
+	Filename string
+	Type     string
+	Size     int
+	Used     int
+	Priority int
+}
+
+// Swaps returns a slice of all configured swap devices on the system.
+func (fs FS) Swaps() ([]*Swap, error) {
+	data, err := util.ReadFileNoStat(fs.proc.Path("swaps"))
+	if err != nil {
+		return nil, err
+	}
+	return parseSwaps(data)
+}
+
+func parseSwaps(info []byte) ([]*Swap, error) {
+	swaps := []*Swap{}
+	scanner := bufio.NewScanner(bytes.NewReader(info))
+	scanner.Scan() // ignore header line
+	for scanner.Scan() {
+		swapString := scanner.Text()
+		parsedSwap, err := parseSwapString(swapString)
+		if err != nil {
+			return nil, err
+		}
+		swaps = append(swaps, parsedSwap)
+	}
+
+	err := scanner.Err()
+	return swaps, err
+}
+
+func parseSwapString(swapString string) (*Swap, error) {
+	var err error
+
+	swapFields := strings.Fields(swapString)
+	swapLength := len(swapFields)
+	if swapLength < 5 {
+		return nil, fmt.Errorf("too few fields in swap string: %s", swapString)
+	}
+
+	swap := &Swap{
+		Filename: swapFields[0],
+		Type:     swapFields[1],
+	}
+
+	swap.Size, err = strconv.Atoi(swapFields[2])
+	if err != nil {
+		return nil, fmt.Errorf("invalid swap size: %s", swapFields[2])
+	}
+	swap.Used, err = strconv.Atoi(swapFields[3])
+	if err != nil {
+		return nil, fmt.Errorf("invalid swap used: %s", swapFields[3])
+	}
+	swap.Priority, err = strconv.Atoi(swapFields[4])
+	if err != nil {
+		return nil, fmt.Errorf("invalid swap priority: %s", swapFields[4])
+	}
+
+	return swap, nil
+}