1
0

Update module prometheus/client_golang to v1

This commit is contained in:
kolaente
2020-04-12 22:06:24 +02:00
parent d28f005552
commit 9559a68416
110 changed files with 26570 additions and 1172 deletions

View File

@ -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
}),

View File

@ -19,6 +19,7 @@ import (
"sort"
"strings"
"github.com/cespare/xxhash/v2"
"github.com/golang/protobuf/proto"
"github.com/prometheus/common/model"
@ -126,24 +127,24 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
return d
}
vh := hashNew()
xxh := xxhash.New()
for _, val := range labelValues {
vh = hashAdd(vh, val)
vh = hashAddByte(vh, separatorByte)
xxh.WriteString(val)
xxh.Write(separatorByteSlice)
}
d.id = vh
d.id = xxh.Sum64()
// Sort labelNames so that order doesn't matter for the hash.
sort.Strings(labelNames)
// Now hash together (in this order) the help string and the sorted
// label names.
lh := hashNew()
lh = hashAdd(lh, help)
lh = hashAddByte(lh, separatorByte)
xxh.Reset()
xxh.WriteString(help)
xxh.Write(separatorByteSlice)
for _, labelName := range labelNames {
lh = hashAdd(lh, labelName)
lh = hashAddByte(lh, separatorByte)
xxh.WriteString(labelName)
xxh.Write(separatorByteSlice)
}
d.dimHash = lh
d.dimHash = xxh.Sum64()
d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels))
for n, v := range constLabels {

View File

@ -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
@ -183,7 +182,6 @@
// method can then expose the gathered metrics in some way. Usually, the metrics
// are served via HTTP on the /metrics endpoint. That's happening in the example
// above. The tools to expose metrics via HTTP are in the promhttp sub-package.
// (The top-level functions in the prometheus package are deprecated.)
//
// Pushing to the Pushgateway
//

View File

@ -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
@ -273,9 +273,12 @@ type GaugeFunc interface {
// NewGaugeFunc creates a new GaugeFunc based on the provided GaugeOpts. The
// value reported is determined by calling the given function from within the
// Write method. Take into account that metric collection may happen
// concurrently. If that results in concurrent calls to Write, like in the case
// where a GaugeFunc is directly registered with Prometheus, the provided
// function must be concurrency-safe.
// concurrently. Therefore, it must be safe to call the provided function
// concurrently.
//
// NewGaugeFunc is a good way to create an “info” style metric with a constant
// value of 1. Example:
// https://github.com/prometheus/common/blob/8558a5b7db3c84fa38b4766966059a7bd5bfa2ee/version/info.go#L36-L56
func NewGaugeFunc(opts GaugeOpts, function func() float64) GaugeFunc {
return newValueFunc(NewDesc(
BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),

View File

@ -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",

View File

@ -20,6 +20,7 @@ import (
"sort"
"sync"
"sync/atomic"
"time"
"github.com/golang/protobuf/proto"
@ -138,7 +139,7 @@ type HistogramOpts struct {
// better covered by target labels set by the scraping Prometheus
// server, or by one specific metric (e.g. a build_info or a
// machine_role metric). See also
// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels-not-static-scraped-labels
ConstLabels Labels
// Buckets defines the buckets into which observations are counted. Each
@ -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(
@ -187,7 +192,8 @@ func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogr
desc: desc,
upperBounds: opts.Buckets,
labelPairs: makeLabelPairs(desc, labelValues),
counts: [2]*histogramCounts{&histogramCounts{}, &histogramCounts{}},
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)
h.observe(v, h.findBucket(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]
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

View File

@ -1,505 +0,0 @@
// Copyright 2014 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 prometheus
import (
"bufio"
"compress/gzip"
"io"
"net"
"net/http"
"strconv"
"strings"
"sync"
"time"
"github.com/prometheus/common/expfmt"
)
// TODO(beorn7): Remove this whole file. It is a partial mirror of
// promhttp/http.go (to avoid circular import chains) where everything HTTP
// related should live. The functions here are just for avoiding
// breakage. Everything is deprecated.
const (
contentTypeHeader = "Content-Type"
contentEncodingHeader = "Content-Encoding"
acceptEncodingHeader = "Accept-Encoding"
)
var gzipPool = sync.Pool{
New: func() interface{} {
return gzip.NewWriter(nil)
},
}
// Handler returns an HTTP handler for the DefaultGatherer. It is
// already instrumented with InstrumentHandler (using "prometheus" as handler
// name).
//
// Deprecated: Please note the issues described in the doc comment of
// InstrumentHandler. You might want to consider using promhttp.Handler instead.
func Handler() http.Handler {
return InstrumentHandler("prometheus", UninstrumentedHandler())
}
// UninstrumentedHandler returns an HTTP handler for the DefaultGatherer.
//
// Deprecated: Use promhttp.HandlerFor(DefaultGatherer, promhttp.HandlerOpts{})
// instead. See there for further documentation.
func UninstrumentedHandler() http.Handler {
return http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
mfs, err := DefaultGatherer.Gather()
if err != nil {
httpError(rsp, err)
return
}
contentType := expfmt.Negotiate(req.Header)
header := rsp.Header()
header.Set(contentTypeHeader, string(contentType))
w := io.Writer(rsp)
if gzipAccepted(req.Header) {
header.Set(contentEncodingHeader, "gzip")
gz := gzipPool.Get().(*gzip.Writer)
defer gzipPool.Put(gz)
gz.Reset(w)
defer gz.Close()
w = gz
}
enc := expfmt.NewEncoder(w, contentType)
for _, mf := range mfs {
if err := enc.Encode(mf); err != nil {
httpError(rsp, err)
return
}
}
})
}
var instLabels = []string{"method", "code"}
type nower interface {
Now() time.Time
}
type nowFunc func() time.Time
func (n nowFunc) Now() time.Time {
return n()
}
var now nower = nowFunc(func() time.Time {
return time.Now()
})
// InstrumentHandler wraps the given HTTP handler for instrumentation. It
// registers four metric collectors (if not already done) and reports HTTP
// metrics to the (newly or already) registered collectors: http_requests_total
// (CounterVec), http_request_duration_microseconds (Summary),
// http_request_size_bytes (Summary), http_response_size_bytes (Summary). Each
// has a constant label named "handler" with the provided handlerName as
// value. http_requests_total is a metric vector partitioned by HTTP method
// (label name "method") and HTTP status code (label name "code").
//
// Deprecated: InstrumentHandler has several issues. Use the tooling provided in
// package promhttp instead. The issues are the following: (1) It uses Summaries
// rather than Histograms. Summaries are not useful if aggregation across
// multiple instances is required. (2) It uses microseconds as unit, which is
// deprecated and should be replaced by seconds. (3) The size of the request is
// calculated in a separate goroutine. Since this calculator requires access to
// the request header, it creates a race with any writes to the header performed
// during request handling. httputil.ReverseProxy is a prominent example for a
// handler performing such writes. (4) It has additional issues with HTTP/2, cf.
// https://github.com/prometheus/client_golang/issues/272.
func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFunc {
return InstrumentHandlerFunc(handlerName, handler.ServeHTTP)
}
// InstrumentHandlerFunc wraps the given function for instrumentation. It
// otherwise works in the same way as InstrumentHandler (and shares the same
// issues).
//
// Deprecated: InstrumentHandlerFunc is deprecated for the same reasons as
// InstrumentHandler is. Use the tooling provided in package promhttp instead.
func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
return InstrumentHandlerFuncWithOpts(
SummaryOpts{
Subsystem: "http",
ConstLabels: Labels{"handler": handlerName},
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
handlerFunc,
)
}
// InstrumentHandlerWithOpts works like InstrumentHandler (and shares the same
// issues) but provides more flexibility (at the cost of a more complex call
// syntax). As InstrumentHandler, this function registers four metric
// collectors, but it uses the provided SummaryOpts to create them. However, the
// fields "Name" and "Help" in the SummaryOpts are ignored. "Name" is replaced
// by "requests_total", "request_duration_microseconds", "request_size_bytes",
// and "response_size_bytes", respectively. "Help" is replaced by an appropriate
// help string. The names of the variable labels of the http_requests_total
// CounterVec are "method" (get, post, etc.), and "code" (HTTP status code).
//
// If InstrumentHandlerWithOpts is called as follows, it mimics exactly the
// behavior of InstrumentHandler:
//
// prometheus.InstrumentHandlerWithOpts(
// prometheus.SummaryOpts{
// Subsystem: "http",
// ConstLabels: prometheus.Labels{"handler": handlerName},
// },
// handler,
// )
//
// Technical detail: "requests_total" is a CounterVec, not a SummaryVec, so it
// cannot use SummaryOpts. Instead, a CounterOpts struct is created internally,
// and all its fields are set to the equally named fields in the provided
// SummaryOpts.
//
// Deprecated: InstrumentHandlerWithOpts is deprecated for the same reasons as
// InstrumentHandler is. Use the tooling provided in package promhttp instead.
func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.HandlerFunc {
return InstrumentHandlerFuncWithOpts(opts, handler.ServeHTTP)
}
// InstrumentHandlerFuncWithOpts works like InstrumentHandlerFunc (and shares
// the same issues) but provides more flexibility (at the cost of a more complex
// call syntax). See InstrumentHandlerWithOpts for details how the provided
// SummaryOpts are used.
//
// Deprecated: InstrumentHandlerFuncWithOpts is deprecated for the same reasons
// as InstrumentHandler is. Use the tooling provided in package promhttp instead.
func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
reqCnt := NewCounterVec(
CounterOpts{
Namespace: opts.Namespace,
Subsystem: opts.Subsystem,
Name: "requests_total",
Help: "Total number of HTTP requests made.",
ConstLabels: opts.ConstLabels,
},
instLabels,
)
if err := Register(reqCnt); err != nil {
if are, ok := err.(AlreadyRegisteredError); ok {
reqCnt = are.ExistingCollector.(*CounterVec)
} else {
panic(err)
}
}
opts.Name = "request_duration_microseconds"
opts.Help = "The HTTP request latencies in microseconds."
reqDur := NewSummary(opts)
if err := Register(reqDur); err != nil {
if are, ok := err.(AlreadyRegisteredError); ok {
reqDur = are.ExistingCollector.(Summary)
} else {
panic(err)
}
}
opts.Name = "request_size_bytes"
opts.Help = "The HTTP request sizes in bytes."
reqSz := NewSummary(opts)
if err := Register(reqSz); err != nil {
if are, ok := err.(AlreadyRegisteredError); ok {
reqSz = are.ExistingCollector.(Summary)
} else {
panic(err)
}
}
opts.Name = "response_size_bytes"
opts.Help = "The HTTP response sizes in bytes."
resSz := NewSummary(opts)
if err := Register(resSz); err != nil {
if are, ok := err.(AlreadyRegisteredError); ok {
resSz = are.ExistingCollector.(Summary)
} else {
panic(err)
}
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
now := time.Now()
delegate := &responseWriterDelegator{ResponseWriter: w}
out := computeApproximateRequestSize(r)
_, cn := w.(http.CloseNotifier)
_, fl := w.(http.Flusher)
_, hj := w.(http.Hijacker)
_, rf := w.(io.ReaderFrom)
var rw http.ResponseWriter
if cn && fl && hj && rf {
rw = &fancyResponseWriterDelegator{delegate}
} else {
rw = delegate
}
handlerFunc(rw, r)
elapsed := float64(time.Since(now)) / float64(time.Microsecond)
method := sanitizeMethod(r.Method)
code := sanitizeCode(delegate.status)
reqCnt.WithLabelValues(method, code).Inc()
reqDur.Observe(elapsed)
resSz.Observe(float64(delegate.written))
reqSz.Observe(float64(<-out))
})
}
func computeApproximateRequestSize(r *http.Request) <-chan int {
// Get URL length in current goroutine for avoiding a race condition.
// HandlerFunc that runs in parallel may modify the URL.
s := 0
if r.URL != nil {
s += len(r.URL.String())
}
out := make(chan int, 1)
go func() {
s += len(r.Method)
s += len(r.Proto)
for name, values := range r.Header {
s += len(name)
for _, value := range values {
s += len(value)
}
}
s += len(r.Host)
// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
if r.ContentLength != -1 {
s += int(r.ContentLength)
}
out <- s
close(out)
}()
return out
}
type responseWriterDelegator struct {
http.ResponseWriter
status int
written int64
wroteHeader bool
}
func (r *responseWriterDelegator) WriteHeader(code int) {
r.status = code
r.wroteHeader = true
r.ResponseWriter.WriteHeader(code)
}
func (r *responseWriterDelegator) Write(b []byte) (int, error) {
if !r.wroteHeader {
r.WriteHeader(http.StatusOK)
}
n, err := r.ResponseWriter.Write(b)
r.written += int64(n)
return n, err
}
type fancyResponseWriterDelegator struct {
*responseWriterDelegator
}
func (f *fancyResponseWriterDelegator) CloseNotify() <-chan bool {
//lint:ignore SA1019 http.CloseNotifier is deprecated but we don't want to
//remove support from client_golang yet.
return f.ResponseWriter.(http.CloseNotifier).CloseNotify()
}
func (f *fancyResponseWriterDelegator) Flush() {
f.ResponseWriter.(http.Flusher).Flush()
}
func (f *fancyResponseWriterDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
return f.ResponseWriter.(http.Hijacker).Hijack()
}
func (f *fancyResponseWriterDelegator) ReadFrom(r io.Reader) (int64, error) {
if !f.wroteHeader {
f.WriteHeader(http.StatusOK)
}
n, err := f.ResponseWriter.(io.ReaderFrom).ReadFrom(r)
f.written += n
return n, err
}
func sanitizeMethod(m string) string {
switch m {
case "GET", "get":
return "get"
case "PUT", "put":
return "put"
case "HEAD", "head":
return "head"
case "POST", "post":
return "post"
case "DELETE", "delete":
return "delete"
case "CONNECT", "connect":
return "connect"
case "OPTIONS", "options":
return "options"
case "NOTIFY", "notify":
return "notify"
default:
return strings.ToLower(m)
}
}
func sanitizeCode(s int) string {
switch s {
case 100:
return "100"
case 101:
return "101"
case 200:
return "200"
case 201:
return "201"
case 202:
return "202"
case 203:
return "203"
case 204:
return "204"
case 205:
return "205"
case 206:
return "206"
case 300:
return "300"
case 301:
return "301"
case 302:
return "302"
case 304:
return "304"
case 305:
return "305"
case 307:
return "307"
case 400:
return "400"
case 401:
return "401"
case 402:
return "402"
case 403:
return "403"
case 404:
return "404"
case 405:
return "405"
case 406:
return "406"
case 407:
return "407"
case 408:
return "408"
case 409:
return "409"
case 410:
return "410"
case 411:
return "411"
case 412:
return "412"
case 413:
return "413"
case 414:
return "414"
case 415:
return "415"
case 416:
return "416"
case 417:
return "417"
case 418:
return "418"
case 500:
return "500"
case 501:
return "501"
case 502:
return "502"
case 503:
return "503"
case 504:
return "504"
case 505:
return "505"
case 428:
return "428"
case 429:
return "429"
case 431:
return "431"
case 511:
return "511"
default:
return strconv.Itoa(s)
}
}
// gzipAccepted returns whether the client will accept gzip-encoded content.
func gzipAccepted(header http.Header) bool {
a := header.Get(acceptEncodingHeader)
parts := strings.Split(a, ",")
for _, part := range parts {
part = strings.TrimSpace(part)
if part == "gzip" || strings.HasPrefix(part, "gzip;") {
return true
}
}
return false
}
// 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.
func httpError(rsp http.ResponseWriter, err error) {
rsp.Header().Del(contentEncodingHeader)
http.Error(
rsp,
"An error has occurred while serving metrics:\n\n"+err.Error(),
http.StatusInternalServerError,
)
}

View File

@ -18,11 +18,12 @@ import (
"time"
"github.com/golang/protobuf/proto"
"github.com/prometheus/common/model"
dto "github.com/prometheus/client_model/go"
)
const separatorByte byte = 255
var separatorByteSlice = []byte{model.SeparatorByte} // For convenient use with xxhash.
// A Metric models a single sample value with its meta data being exported to
// Prometheus. Implementations of Metric in this package are Gauge, Counter,

View File

@ -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)
}

View File

@ -16,8 +16,6 @@ package prometheus
import (
"errors"
"os"
"github.com/prometheus/procfs"
)
type processCollector struct {
@ -59,20 +57,9 @@ type ProcessCollectorOpts struct {
// collector for the current process with an empty namespace string and no error
// reporting.
//
// Currently, the collector depends on a Linux-style proc filesystem and
// therefore only exports metrics for Linux.
//
// Note: An older version of this function had the following signature:
//
// NewProcessCollector(pid int, namespace string) Collector
//
// Most commonly, it was called as
//
// NewProcessCollector(os.Getpid(), "")
//
// The following call of the current version is equivalent to the above:
//
// NewProcessCollector(ProcessCollectorOpts{})
// The collector only works on operating systems with a Linux-style proc
// filesystem and on Microsoft Windows. On other operating systems, it will not
// collect any metrics.
func NewProcessCollector(opts ProcessCollectorOpts) Collector {
ns := ""
if len(opts.Namespace) > 0 {
@ -126,7 +113,7 @@ func NewProcessCollector(opts ProcessCollectorOpts) Collector {
}
// Set up process metric collection if supported by the runtime.
if _, err := procfs.NewDefaultFS(); err == nil {
if canCollectProcess() {
c.collectFn = c.processCollect
} else {
c.collectFn = func(ch chan<- Metric) {
@ -153,46 +140,6 @@ func (c *processCollector) Collect(ch chan<- Metric) {
c.collectFn(ch)
}
func (c *processCollector) processCollect(ch chan<- Metric) {
pid, err := c.pidFn()
if err != nil {
c.reportError(ch, nil, err)
return
}
p, err := procfs.NewProc(pid)
if err != nil {
c.reportError(ch, nil, err)
return
}
if stat, err := p.Stat(); err == nil {
ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
if startTime, err := stat.StartTime(); err == nil {
ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
} else {
c.reportError(ch, c.startTime, err)
}
} else {
c.reportError(ch, nil, err)
}
if fds, err := p.FileDescriptorsLen(); err == nil {
ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
} else {
c.reportError(ch, c.openFDs, err)
}
if limits, err := p.Limits(); err == nil {
ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(limits.AddressSpace))
} else {
c.reportError(ch, nil, err)
}
}
func (c *processCollector) reportError(ch chan<- Metric, desc *Desc, err error) {
if !c.reportErrors {
return

View File

@ -0,0 +1,65 @@
// 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 prometheus
import (
"github.com/prometheus/procfs"
)
func canCollectProcess() bool {
_, err := procfs.NewDefaultFS()
return err == nil
}
func (c *processCollector) processCollect(ch chan<- Metric) {
pid, err := c.pidFn()
if err != nil {
c.reportError(ch, nil, err)
return
}
p, err := procfs.NewProc(pid)
if err != nil {
c.reportError(ch, nil, err)
return
}
if stat, err := p.Stat(); err == nil {
ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
if startTime, err := stat.StartTime(); err == nil {
ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
} else {
c.reportError(ch, c.startTime, err)
}
} else {
c.reportError(ch, nil, err)
}
if fds, err := p.FileDescriptorsLen(); err == nil {
ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
} else {
c.reportError(ch, c.openFDs, err)
}
if limits, err := p.Limits(); err == nil {
ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(limits.AddressSpace))
} else {
c.reportError(ch, nil, err)
}
}

View File

@ -0,0 +1,112 @@
// 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 prometheus
import (
"syscall"
"unsafe"
"golang.org/x/sys/windows"
)
func canCollectProcess() bool {
return true
}
var (
modpsapi = syscall.NewLazyDLL("psapi.dll")
modkernel32 = syscall.NewLazyDLL("kernel32.dll")
procGetProcessMemoryInfo = modpsapi.NewProc("GetProcessMemoryInfo")
procGetProcessHandleCount = modkernel32.NewProc("GetProcessHandleCount")
)
type processMemoryCounters struct {
// https://docs.microsoft.com/en-us/windows/desktop/api/psapi/ns-psapi-_process_memory_counters_ex
_ uint32
PageFaultCount uint32
PeakWorkingSetSize uint64
WorkingSetSize uint64
QuotaPeakPagedPoolUsage uint64
QuotaPagedPoolUsage uint64
QuotaPeakNonPagedPoolUsage uint64
QuotaNonPagedPoolUsage uint64
PagefileUsage uint64
PeakPagefileUsage uint64
PrivateUsage uint64
}
func getProcessMemoryInfo(handle windows.Handle) (processMemoryCounters, error) {
mem := processMemoryCounters{}
r1, _, err := procGetProcessMemoryInfo.Call(
uintptr(handle),
uintptr(unsafe.Pointer(&mem)),
uintptr(unsafe.Sizeof(mem)),
)
if r1 != 1 {
return mem, err
} else {
return mem, nil
}
}
func getProcessHandleCount(handle windows.Handle) (uint32, error) {
var count uint32
r1, _, err := procGetProcessHandleCount.Call(
uintptr(handle),
uintptr(unsafe.Pointer(&count)),
)
if r1 != 1 {
return 0, err
} else {
return count, nil
}
}
func (c *processCollector) processCollect(ch chan<- Metric) {
h, err := windows.GetCurrentProcess()
if err != nil {
c.reportError(ch, nil, err)
return
}
var startTime, exitTime, kernelTime, userTime windows.Filetime
err = windows.GetProcessTimes(h, &startTime, &exitTime, &kernelTime, &userTime)
if err != nil {
c.reportError(ch, nil, err)
return
}
ch <- MustNewConstMetric(c.startTime, GaugeValue, float64(startTime.Nanoseconds()/1e9))
ch <- MustNewConstMetric(c.cpuTotal, CounterValue, fileTimeToSeconds(kernelTime)+fileTimeToSeconds(userTime))
mem, err := getProcessMemoryInfo(h)
if err != nil {
c.reportError(ch, nil, err)
return
}
ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(mem.PrivateUsage))
ch <- MustNewConstMetric(c.rss, GaugeValue, float64(mem.WorkingSetSize))
handles, err := getProcessHandleCount(h)
if err != nil {
c.reportError(ch, nil, err)
return
}
ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(handles))
ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(16*1024*1024)) // Windows has a hard-coded max limit, not per-process.
}
func fileTimeToSeconds(ft windows.Filetime) float64 {
return float64(uint64(ft.HighDateTime)<<32+uint64(ft.LowDateTime)) / 1e7
}

View File

@ -11,11 +11,16 @@
// See the License for the specific language governing permissions and
// limitations under the License.
// Package promauto provides constructors for the usual Prometheus metrics that
// return them already registered with the global registry
// (prometheus.DefaultRegisterer). This allows very compact code, avoiding any
// references to the registry altogether, but all the constructors in this
// package will panic if the registration fails.
// Package promauto provides alternative constructors for the fundamental
// Prometheus metric types and their …Vec and …Func variants. The difference to
// their counterparts in the prometheus package is that the promauto
// constructors return Collectors that are already registered with a
// registry. There are two sets of constructors. The constructors in the first
// set are top-level functions, while the constructors in the other set are
// methods of the Factory type. The top-level function return Collectors
// registered with the global registry (prometheus.DefaultRegisterer), while the
// methods return Collectors registered with the registry the Factory was
// constructed with. All constructors panic if the registration fails.
//
// The following example is a complete program to create a histogram of normally
// distributed random numbers from the math/rand package:
@ -79,51 +84,78 @@
// http.ListenAndServe(":1971", nil)
// }
//
// A Factory is created with the With(prometheus.Registerer) function, which
// enables two usage pattern. With(prometheus.Registerer) can be called once per
// line:
//
// var (
// reg = prometheus.NewRegistry()
// randomNumbers = promauto.With(reg).NewHistogram(prometheus.HistogramOpts{
// Name: "random_numbers",
// Help: "A histogram of normally distributed random numbers.",
// Buckets: prometheus.LinearBuckets(-3, .1, 61),
// })
// requestCount = promauto.With(reg).NewCounterVec(
// prometheus.CounterOpts{
// Name: "http_requests_total",
// Help: "Total number of HTTP requests by status code end method.",
// },
// []string{"code", "method"},
// )
// )
//
// Or it can be used to create a Factory once to be used multiple times:
//
// var (
// reg = prometheus.NewRegistry()
// factory = promauto.With(reg)
// randomNumbers = factory.NewHistogram(prometheus.HistogramOpts{
// Name: "random_numbers",
// Help: "A histogram of normally distributed random numbers.",
// Buckets: prometheus.LinearBuckets(-3, .1, 61),
// })
// requestCount = factory.NewCounterVec(
// prometheus.CounterOpts{
// Name: "http_requests_total",
// Help: "Total number of HTTP requests by status code end method.",
// },
// []string{"code", "method"},
// )
// )
//
// This appears very handy. So why are these constructors locked away in a
// separate package? There are two caveats:
// separate package?
//
// First, in more complex programs, global state is often quite problematic.
// That's the reason why the metrics constructors in the prometheus package do
// not interact with the global prometheus.DefaultRegisterer on their own. You
// are free to use the Register or MustRegister functions to register them with
// the global prometheus.DefaultRegisterer, but you could as well choose a local
// Registerer (usually created with prometheus.NewRegistry, but there are other
// scenarios, e.g. testing).
// The main problem is that registration may fail, e.g. if a metric inconsistent
// with the newly to be registered one is already registered. Therefore, the
// Register method in the prometheus.Registerer interface returns an error, and
// the same is the case for the top-level prometheus.Register function that
// registers with the global registry. The prometheus package also provides
// MustRegister versions for both. They panic if the registration fails, and
// they clearly call this out by using the Must… idiom. Panicking is a bit
// problematic here because it doesn't just happen on input provided by the
// caller that is invalid on its own. Things are a bit more subtle here: Metric
// creation and registration tend to be spread widely over the codebase. It can
// easily happen that an incompatible metric is added to an unrelated part of
// the code, and suddenly code that used to work perfectly fine starts to panic
// (provided that the registration of the newly added metric happens before the
// registration of the previously existing metric). This may come as an even
// bigger surprise with the global registry, where simply importing another
// package can trigger a panic (if the newly imported package registers metrics
// in its init function). At least, in the prometheus package, creation of
// metrics and other collectors is separate from registration. You first create
// the metric, and then you decide explicitly if you want to register it with a
// local or the global registry, and if you want to handle the error or risk a
// panic. With the constructors in the promauto package, registration is
// automatic, and if it fails, it will always panic. Furthermore, the
// constructors will often be called in the var section of a file, which means
// that panicking will happen as a side effect of merely importing a package.
//
// The second issue is that registration may fail, e.g. if a metric inconsistent
// with the newly to be registered one is already registered. But how to signal
// and handle a panic in the automatic registration with the default registry?
// The only way is panicking. While panicking on invalid input provided by the
// programmer is certainly fine, things are a bit more subtle in this case: You
// might just add another package to the program, and that package (in its init
// function) happens to register a metric with the same name as your code. Now,
// all of a sudden, either your code or the code of the newly imported package
// panics, depending on initialization order, without any opportunity to handle
// the case gracefully. Even worse is a scenario where registration happens
// later during the runtime (e.g. upon loading some kind of plugin), where the
// panic could be triggered long after the code has been deployed to
// production. A possibility to panic should be explicitly called out by the
// Must… idiom, cf. prometheus.MustRegister. But adding a separate set of
// constructors in the prometheus package called MustRegisterNewCounterVec or
// similar would be quite unwieldy. Adding an extra MustRegister method to each
// metric, returning the registered metric, would result in nice code for those
// using the method, but would pollute every single metric interface for
// everybody avoiding the global registry.
// A separate package allows conservative users to entirely ignore it. And
// whoever wants to use it, will do so explicitly, with an opportunity to read
// this warning.
//
// To address both issues, the problematic auto-registering and possibly
// panicking constructors are all in this package with a clear warning
// ahead. And whoever cares about avoiding global state and possibly panicking
// function calls can simply ignore the existence of the promauto package
// altogether.
//
// A final note: There is a similar case in the net/http package of the standard
// library. It has DefaultServeMux as a global instance of ServeMux, and the
// Handle function acts on it, panicking if a handler for the same pattern has
// already been registered. However, one might argue that the whole HTTP routing
// is usually set up closely together in the same package or file, while
// Prometheus metrics tend to be spread widely over the codebase, increasing the
// chance of surprising registration failures. Furthermore, the use of global
// state in net/http has been criticized widely, and some avoid it altogether.
// Enjoy promauto responsibly!
package promauto
import "github.com/prometheus/client_golang/prometheus"
@ -132,9 +164,7 @@ import "github.com/prometheus/client_golang/prometheus"
// but it automatically registers the Counter with the
// prometheus.DefaultRegisterer. If the registration fails, NewCounter panics.
func NewCounter(opts prometheus.CounterOpts) prometheus.Counter {
c := prometheus.NewCounter(opts)
prometheus.MustRegister(c)
return c
return With(prometheus.DefaultRegisterer).NewCounter(opts)
}
// NewCounterVec works like the function of the same name in the prometheus
@ -142,9 +172,7 @@ func NewCounter(opts prometheus.CounterOpts) prometheus.Counter {
// prometheus.DefaultRegisterer. If the registration fails, NewCounterVec
// panics.
func NewCounterVec(opts prometheus.CounterOpts, labelNames []string) *prometheus.CounterVec {
c := prometheus.NewCounterVec(opts, labelNames)
prometheus.MustRegister(c)
return c
return With(prometheus.DefaultRegisterer).NewCounterVec(opts, labelNames)
}
// NewCounterFunc works like the function of the same name in the prometheus
@ -152,45 +180,35 @@ func NewCounterVec(opts prometheus.CounterOpts, labelNames []string) *prometheus
// prometheus.DefaultRegisterer. If the registration fails, NewCounterFunc
// panics.
func NewCounterFunc(opts prometheus.CounterOpts, function func() float64) prometheus.CounterFunc {
g := prometheus.NewCounterFunc(opts, function)
prometheus.MustRegister(g)
return g
return With(prometheus.DefaultRegisterer).NewCounterFunc(opts, function)
}
// NewGauge works like the function of the same name in the prometheus package
// but it automatically registers the Gauge with the
// prometheus.DefaultRegisterer. If the registration fails, NewGauge panics.
func NewGauge(opts prometheus.GaugeOpts) prometheus.Gauge {
g := prometheus.NewGauge(opts)
prometheus.MustRegister(g)
return g
return With(prometheus.DefaultRegisterer).NewGauge(opts)
}
// NewGaugeVec works like the function of the same name in the prometheus
// package but it automatically registers the GaugeVec with the
// prometheus.DefaultRegisterer. If the registration fails, NewGaugeVec panics.
func NewGaugeVec(opts prometheus.GaugeOpts, labelNames []string) *prometheus.GaugeVec {
g := prometheus.NewGaugeVec(opts, labelNames)
prometheus.MustRegister(g)
return g
return With(prometheus.DefaultRegisterer).NewGaugeVec(opts, labelNames)
}
// NewGaugeFunc works like the function of the same name in the prometheus
// package but it automatically registers the GaugeFunc with the
// prometheus.DefaultRegisterer. If the registration fails, NewGaugeFunc panics.
func NewGaugeFunc(opts prometheus.GaugeOpts, function func() float64) prometheus.GaugeFunc {
g := prometheus.NewGaugeFunc(opts, function)
prometheus.MustRegister(g)
return g
return With(prometheus.DefaultRegisterer).NewGaugeFunc(opts, function)
}
// NewSummary works like the function of the same name in the prometheus package
// but it automatically registers the Summary with the
// prometheus.DefaultRegisterer. If the registration fails, NewSummary panics.
func NewSummary(opts prometheus.SummaryOpts) prometheus.Summary {
s := prometheus.NewSummary(opts)
prometheus.MustRegister(s)
return s
return With(prometheus.DefaultRegisterer).NewSummary(opts)
}
// NewSummaryVec works like the function of the same name in the prometheus
@ -198,18 +216,14 @@ func NewSummary(opts prometheus.SummaryOpts) prometheus.Summary {
// prometheus.DefaultRegisterer. If the registration fails, NewSummaryVec
// panics.
func NewSummaryVec(opts prometheus.SummaryOpts, labelNames []string) *prometheus.SummaryVec {
s := prometheus.NewSummaryVec(opts, labelNames)
prometheus.MustRegister(s)
return s
return With(prometheus.DefaultRegisterer).NewSummaryVec(opts, labelNames)
}
// NewHistogram works like the function of the same name in the prometheus
// package but it automatically registers the Histogram with the
// prometheus.DefaultRegisterer. If the registration fails, NewHistogram panics.
func NewHistogram(opts prometheus.HistogramOpts) prometheus.Histogram {
h := prometheus.NewHistogram(opts)
prometheus.MustRegister(h)
return h
return With(prometheus.DefaultRegisterer).NewHistogram(opts)
}
// NewHistogramVec works like the function of the same name in the prometheus
@ -217,7 +231,144 @@ func NewHistogram(opts prometheus.HistogramOpts) prometheus.Histogram {
// prometheus.DefaultRegisterer. If the registration fails, NewHistogramVec
// panics.
func NewHistogramVec(opts prometheus.HistogramOpts, labelNames []string) *prometheus.HistogramVec {
h := prometheus.NewHistogramVec(opts, labelNames)
prometheus.MustRegister(h)
return With(prometheus.DefaultRegisterer).NewHistogramVec(opts, labelNames)
}
// NewUntypedFunc works like the function of the same name in the prometheus
// package but it automatically registers the UntypedFunc with the
// prometheus.DefaultRegisterer. If the registration fails, NewUntypedFunc
// panics.
func NewUntypedFunc(opts prometheus.UntypedOpts, function func() float64) prometheus.UntypedFunc {
return With(prometheus.DefaultRegisterer).NewUntypedFunc(opts, function)
}
// Factory provides factory methods to create Collectors that are automatically
// registered with a Registerer. Create a Factory with the With function,
// providing a Registerer to auto-register created Collectors with. The zero
// value of a Factory creates Collectors that are not registered with any
// Registerer. All methods of the Factory panic if the registration fails.
type Factory struct {
r prometheus.Registerer
}
// With creates a Factory using the provided Registerer for registration of the
// created Collectors.
func With(r prometheus.Registerer) Factory { return Factory{r} }
// NewCounter works like the function of the same name in the prometheus package
// but it automatically registers the Counter with the Factory's Registerer.
func (f Factory) NewCounter(opts prometheus.CounterOpts) prometheus.Counter {
c := prometheus.NewCounter(opts)
if f.r != nil {
f.r.MustRegister(c)
}
return c
}
// NewCounterVec works like the function of the same name in the prometheus
// package but it automatically registers the CounterVec with the Factory's
// Registerer.
func (f Factory) NewCounterVec(opts prometheus.CounterOpts, labelNames []string) *prometheus.CounterVec {
c := prometheus.NewCounterVec(opts, labelNames)
if f.r != nil {
f.r.MustRegister(c)
}
return c
}
// NewCounterFunc works like the function of the same name in the prometheus
// package but it automatically registers the CounterFunc with the Factory's
// Registerer.
func (f Factory) NewCounterFunc(opts prometheus.CounterOpts, function func() float64) prometheus.CounterFunc {
c := prometheus.NewCounterFunc(opts, function)
if f.r != nil {
f.r.MustRegister(c)
}
return c
}
// NewGauge works like the function of the same name in the prometheus package
// but it automatically registers the Gauge with the Factory's Registerer.
func (f Factory) NewGauge(opts prometheus.GaugeOpts) prometheus.Gauge {
g := prometheus.NewGauge(opts)
if f.r != nil {
f.r.MustRegister(g)
}
return g
}
// NewGaugeVec works like the function of the same name in the prometheus
// package but it automatically registers the GaugeVec with the Factory's
// Registerer.
func (f Factory) NewGaugeVec(opts prometheus.GaugeOpts, labelNames []string) *prometheus.GaugeVec {
g := prometheus.NewGaugeVec(opts, labelNames)
if f.r != nil {
f.r.MustRegister(g)
}
return g
}
// NewGaugeFunc works like the function of the same name in the prometheus
// package but it automatically registers the GaugeFunc with the Factory's
// Registerer.
func (f Factory) NewGaugeFunc(opts prometheus.GaugeOpts, function func() float64) prometheus.GaugeFunc {
g := prometheus.NewGaugeFunc(opts, function)
if f.r != nil {
f.r.MustRegister(g)
}
return g
}
// NewSummary works like the function of the same name in the prometheus package
// but it automatically registers the Summary with the Factory's Registerer.
func (f Factory) NewSummary(opts prometheus.SummaryOpts) prometheus.Summary {
s := prometheus.NewSummary(opts)
if f.r != nil {
f.r.MustRegister(s)
}
return s
}
// NewSummaryVec works like the function of the same name in the prometheus
// package but it automatically registers the SummaryVec with the Factory's
// Registerer.
func (f Factory) NewSummaryVec(opts prometheus.SummaryOpts, labelNames []string) *prometheus.SummaryVec {
s := prometheus.NewSummaryVec(opts, labelNames)
if f.r != nil {
f.r.MustRegister(s)
}
return s
}
// NewHistogram works like the function of the same name in the prometheus
// package but it automatically registers the Histogram with the Factory's
// Registerer.
func (f Factory) NewHistogram(opts prometheus.HistogramOpts) prometheus.Histogram {
h := prometheus.NewHistogram(opts)
if f.r != nil {
f.r.MustRegister(h)
}
return h
}
// NewHistogramVec works like the function of the same name in the prometheus
// package but it automatically registers the HistogramVec with the Factory's
// Registerer.
func (f Factory) NewHistogramVec(opts prometheus.HistogramOpts, labelNames []string) *prometheus.HistogramVec {
h := prometheus.NewHistogramVec(opts, labelNames)
if f.r != nil {
f.r.MustRegister(h)
}
return h
}
// NewUntypedFunc works like the function of the same name in the prometheus
// package but it automatically registers the UntypedFunc with the Factory's
// Registerer.
func (f Factory) NewUntypedFunc(opts prometheus.UntypedOpts, function func() float64) prometheus.UntypedFunc {
u := prometheus.NewUntypedFunc(opts, function)
if f.r != nil {
f.r.MustRegister(u)
}
return u
}

View File

@ -53,15 +53,21 @@ 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) {
// If applicable, call WriteHeader here so that observeWriteHeader is
// handled appropriately.
if !r.wroteHeader {
r.WriteHeader(http.StatusOK)
}
@ -82,12 +88,19 @@ func (d closeNotifierDelegator) CloseNotify() <-chan bool {
return d.ResponseWriter.(http.CloseNotifier).CloseNotify()
}
func (d flusherDelegator) Flush() {
// If applicable, call WriteHeader here so that observeWriteHeader is
// handled appropriately.
if !d.wroteHeader {
d.WriteHeader(http.StatusOK)
}
d.ResponseWriter.(http.Flusher).Flush()
}
func (d hijackerDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
return d.ResponseWriter.(http.Hijacker).Hijack()
}
func (d readerFromDelegator) ReadFrom(re io.Reader) (int64, error) {
// If applicable, call WriteHeader here so that observeWriteHeader is
// handled appropriately.
if !d.wroteHeader {
d.WriteHeader(http.StatusOK)
}

View File

@ -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(

View File

@ -25,6 +25,7 @@ import (
"sync"
"unicode/utf8"
"github.com/cespare/xxhash/v2"
"github.com/golang/protobuf/proto"
"github.com/prometheus/common/expfmt"
@ -74,7 +75,7 @@ func NewRegistry() *Registry {
// NewPedanticRegistry returns a registry that checks during collection if each
// collected Metric is consistent with its reported Desc, and if the Desc has
// actually been registered with the registry. Unchecked Collectors (those whose
// Describe methed does not yield any descriptors) are excluded from the check.
// Describe method does not yield any descriptors) are excluded from the check.
//
// Usually, a Registry will be happy as long as the union of all collected
// Metrics is consistent and valid even if some metrics are not consistent with
@ -266,7 +267,7 @@ func (r *Registry) Register(c Collector) error {
descChan = make(chan *Desc, capDescChan)
newDescIDs = map[uint64]struct{}{}
newDimHashesByName = map[string]uint64{}
collectorID uint64 // Just a sum of all desc IDs.
collectorID uint64 // All desc IDs XOR'd together.
duplicateDescErr error
)
go func() {
@ -293,12 +294,12 @@ func (r *Registry) Register(c Collector) error {
if _, exists := r.descIDs[desc.id]; exists {
duplicateDescErr = fmt.Errorf("descriptor %s already exists with the same fully-qualified name and const label values", desc)
}
// If it is not a duplicate desc in this collector, add it to
// If it is not a duplicate desc in this collector, XOR it to
// the collectorID. (We allow duplicate descs within the same
// collector, but their existence must be a no-op.)
if _, exists := newDescIDs[desc.id]; !exists {
newDescIDs[desc.id] = struct{}{}
collectorID += desc.id
collectorID ^= desc.id
}
// Are all the label names and the help string consistent with
@ -325,9 +326,17 @@ func (r *Registry) Register(c Collector) error {
return nil
}
if existing, exists := r.collectorsByID[collectorID]; exists {
return AlreadyRegisteredError{
ExistingCollector: existing,
NewCollector: c,
switch e := existing.(type) {
case *wrappingCollector:
return AlreadyRegisteredError{
ExistingCollector: e.unwrapRecursively(),
NewCollector: c,
}
default:
return AlreadyRegisteredError{
ExistingCollector: e,
NewCollector: c,
}
}
}
// If the collectorID is new, but at least one of the descs existed
@ -352,7 +361,7 @@ func (r *Registry) Unregister(c Collector) bool {
var (
descChan = make(chan *Desc, capDescChan)
descIDs = map[uint64]struct{}{}
collectorID uint64 // Just a sum of the desc IDs.
collectorID uint64 // All desc IDs XOR'd together.
)
go func() {
c.Describe(descChan)
@ -360,7 +369,7 @@ func (r *Registry) Unregister(c Collector) bool {
}()
for desc := range descChan {
if _, exists := descIDs[desc.id]; !exists {
collectorID += desc.id
collectorID ^= desc.id
descIDs[desc.id] = struct{}{}
}
}
@ -867,9 +876,9 @@ func checkMetricConsistency(
}
// Is the metric unique (i.e. no other metric with the same name and the same labels)?
h := hashNew()
h = hashAdd(h, name)
h = hashAddByte(h, separatorByte)
h := xxhash.New()
h.WriteString(name)
h.Write(separatorByteSlice)
// Make sure label pairs are sorted. We depend on it for the consistency
// check.
if !sort.IsSorted(labelPairSorter(dtoMetric.Label)) {
@ -880,18 +889,19 @@ func checkMetricConsistency(
dtoMetric.Label = copiedLabels
}
for _, lp := range dtoMetric.Label {
h = hashAdd(h, lp.GetName())
h = hashAddByte(h, separatorByte)
h = hashAdd(h, lp.GetValue())
h = hashAddByte(h, separatorByte)
h.WriteString(lp.GetName())
h.Write(separatorByteSlice)
h.WriteString(lp.GetValue())
h.Write(separatorByteSlice)
}
if _, exists := metricHashes[h]; exists {
hSum := h.Sum64()
if _, exists := metricHashes[hSum]; exists {
return fmt.Errorf(
"collected metric %q { %s} was collected before with the same name and label values",
name, dtoMetric,
)
}
metricHashes[h] = struct{}{}
metricHashes[hSum] = struct{}{}
return nil
}

View File

@ -58,16 +58,8 @@ type Summary interface {
Observe(float64)
}
// DefObjectives are the default Summary quantile values.
//
// Deprecated: DefObjectives will not be used as the default objectives in
// v1.0.0 of the library. The default Summary will have no quantiles then.
var (
DefObjectives = map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001}
errQuantileLabelNotAllowed = fmt.Errorf(
"%q is not allowed as label name in summaries", quantileLabel,
)
var errQuantileLabelNotAllowed = fmt.Errorf(
"%q is not allowed as label name in summaries", quantileLabel,
)
// Default values for SummaryOpts.
@ -123,14 +115,8 @@ type SummaryOpts struct {
// Objectives defines the quantile rank estimates with their respective
// absolute error. If Objectives[q] = e, then the value reported for q
// will be the φ-quantile value for some φ between q-e and q+e. The
// default value is DefObjectives. It is used if Objectives is left at
// its zero value (i.e. nil). To create a Summary without Objectives,
// set it to an empty map (i.e. map[float64]float64{}).
//
// Note that the current value of DefObjectives is deprecated. It will
// be replaced by an empty map in v1.0.0 of the library. Please
// explicitly set Objectives to the desired value to avoid problems
// during the transition.
// default value is an empty map, resulting in a summary without
// quantiles.
Objectives map[float64]float64
// MaxAge defines the duration for which an observation stays relevant
@ -199,7 +185,7 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
}
if opts.Objectives == nil {
opts.Objectives = DefObjectives
opts.Objectives = map[float64]float64{}
}
if opts.MaxAge < 0 {
@ -222,7 +208,7 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
s := &noObjectivesSummary{
desc: desc,
labelPairs: makeLabelPairs(desc, labelValues),
counts: [2]*summaryCounts{&summaryCounts{}, &summaryCounts{}},
counts: [2]*summaryCounts{{}, {}},
}
s.init(s) // Init self-collection.
return s

View File

@ -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
}

View File

@ -24,7 +24,7 @@ import (
// their label values. metricVec is not used directly (and therefore
// unexported). It is used as a building block for implementations of vectors of
// a given metric type, like GaugeVec, CounterVec, SummaryVec, and HistogramVec.
// It also handles label currying. It uses basicMetricVec internally.
// It also handles label currying.
type metricVec struct {
*metricMap
@ -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

View File

@ -32,6 +32,12 @@ import (
// WrapRegistererWith provides a way to add fixed labels to a subset of
// Collectors. It should not be used to add fixed labels to all metrics exposed.
//
// Conflicts between Collectors registered through the original Registerer with
// Collectors registered through the wrapping Registerer will still be
// detected. Any AlreadyRegisteredError returned by the Register method of
// either Registerer will contain the ExistingCollector in the form it was
// provided to the respective registry.
//
// The Collector example demonstrates a use of WrapRegistererWith.
func WrapRegistererWith(labels Labels, reg Registerer) Registerer {
return &wrappingRegisterer{
@ -54,6 +60,12 @@ func WrapRegistererWith(labels Labels, reg Registerer) Registerer {
// (see NewGoCollector) and the process collector (see NewProcessCollector). (In
// fact, those metrics are already prefixed with “go_” or “process_”,
// respectively.)
//
// Conflicts between Collectors registered through the original Registerer with
// Collectors registered through the wrapping Registerer will still be
// detected. Any AlreadyRegisteredError returned by the Register method of
// either Registerer will contain the ExistingCollector in the form it was
// provided to the respective registry.
func WrapRegistererWithPrefix(prefix string, reg Registerer) Registerer {
return &wrappingRegisterer{
wrappedRegisterer: reg,
@ -123,6 +135,15 @@ func (c *wrappingCollector) Describe(ch chan<- *Desc) {
}
}
func (c *wrappingCollector) unwrapRecursively() Collector {
switch wc := c.wrappedCollector.(type) {
case *wrappingCollector:
return wc.unwrapRecursively()
default:
return wc
}
}
type wrappingMetric struct {
wrappedMetric Metric
prefix string