diff --git a/main.go b/main.go
index 0379c50..5d6fba4 100644
--- a/main.go
+++ b/main.go
@@ -25,6 +25,7 @@ import (
"github.com/howeyc/fsnotify"
"github.com/prometheus/client_golang/prometheus"
+ "github.com/prometheus/client_golang/prometheus/promhttp"
"github.com/prometheus/common/log"
"github.com/prometheus/common/version"
"gopkg.in/alecthomas/kingpin.v2"
@@ -37,8 +38,7 @@ func init() {
}
func serveHTTP(listenAddress, metricsEndpoint string) {
- //lint:ignore SA1019 prometheus.Handler() is deprecated.
- http.Handle(metricsEndpoint, prometheus.Handler())
+ http.Handle(metricsEndpoint, promhttp.Handler())
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte(`
StatsD Exporter
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go
new file mode 100644
index 0000000..67b56d3
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go
@@ -0,0 +1,199 @@
+// Copyright 2017 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 promhttp
+
+import (
+ "bufio"
+ "io"
+ "net"
+ "net/http"
+)
+
+const (
+ closeNotifier = 1 << iota
+ flusher
+ hijacker
+ readerFrom
+ pusher
+)
+
+type delegator interface {
+ http.ResponseWriter
+
+ Status() int
+ Written() int64
+}
+
+type responseWriterDelegator struct {
+ http.ResponseWriter
+
+ handler, method string
+ status int
+ written int64
+ wroteHeader bool
+ observeWriteHeader func(int)
+}
+
+func (r *responseWriterDelegator) Status() int {
+ return r.status
+}
+
+func (r *responseWriterDelegator) Written() int64 {
+ return r.written
+}
+
+func (r *responseWriterDelegator) WriteHeader(code int) {
+ 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 !r.wroteHeader {
+ r.WriteHeader(http.StatusOK)
+ }
+ n, err := r.ResponseWriter.Write(b)
+ r.written += int64(n)
+ return n, err
+}
+
+type closeNotifierDelegator struct{ *responseWriterDelegator }
+type flusherDelegator struct{ *responseWriterDelegator }
+type hijackerDelegator struct{ *responseWriterDelegator }
+type readerFromDelegator struct{ *responseWriterDelegator }
+
+func (d closeNotifierDelegator) CloseNotify() <-chan bool {
+ return d.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+func (d flusherDelegator) Flush() {
+ 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 !d.wroteHeader {
+ d.WriteHeader(http.StatusOK)
+ }
+ n, err := d.ResponseWriter.(io.ReaderFrom).ReadFrom(re)
+ d.written += n
+ return n, err
+}
+
+var pickDelegator = make([]func(*responseWriterDelegator) delegator, 32)
+
+func init() {
+ // TODO(beorn7): Code generation would help here.
+ pickDelegator[0] = func(d *responseWriterDelegator) delegator { // 0
+ return d
+ }
+ pickDelegator[closeNotifier] = func(d *responseWriterDelegator) delegator { // 1
+ return closeNotifierDelegator{d}
+ }
+ pickDelegator[flusher] = func(d *responseWriterDelegator) delegator { // 2
+ return flusherDelegator{d}
+ }
+ pickDelegator[flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 3
+ return struct {
+ *responseWriterDelegator
+ http.Flusher
+ http.CloseNotifier
+ }{d, flusherDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[hijacker] = func(d *responseWriterDelegator) delegator { // 4
+ return hijackerDelegator{d}
+ }
+ pickDelegator[hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 5
+ return struct {
+ *responseWriterDelegator
+ http.Hijacker
+ http.CloseNotifier
+ }{d, hijackerDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 6
+ return struct {
+ *responseWriterDelegator
+ http.Hijacker
+ http.Flusher
+ }{d, hijackerDelegator{d}, flusherDelegator{d}}
+ }
+ pickDelegator[hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 7
+ return struct {
+ *responseWriterDelegator
+ http.Hijacker
+ http.Flusher
+ http.CloseNotifier
+ }{d, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[readerFrom] = func(d *responseWriterDelegator) delegator { // 8
+ return readerFromDelegator{d}
+ }
+ pickDelegator[readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 9
+ return struct {
+ *responseWriterDelegator
+ io.ReaderFrom
+ http.CloseNotifier
+ }{d, readerFromDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 10
+ return struct {
+ *responseWriterDelegator
+ io.ReaderFrom
+ http.Flusher
+ }{d, readerFromDelegator{d}, flusherDelegator{d}}
+ }
+ pickDelegator[readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 11
+ return struct {
+ *responseWriterDelegator
+ io.ReaderFrom
+ http.Flusher
+ http.CloseNotifier
+ }{d, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 12
+ return struct {
+ *responseWriterDelegator
+ io.ReaderFrom
+ http.Hijacker
+ }{d, readerFromDelegator{d}, hijackerDelegator{d}}
+ }
+ pickDelegator[readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 13
+ return struct {
+ *responseWriterDelegator
+ io.ReaderFrom
+ http.Hijacker
+ http.CloseNotifier
+ }{d, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 14
+ return struct {
+ *responseWriterDelegator
+ io.ReaderFrom
+ http.Hijacker
+ http.Flusher
+ }{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+ }
+ pickDelegator[readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 15
+ return struct {
+ *responseWriterDelegator
+ io.ReaderFrom
+ http.Hijacker
+ http.Flusher
+ http.CloseNotifier
+ }{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+ }
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_1_8.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_1_8.go
new file mode 100644
index 0000000..31a7069
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_1_8.go
@@ -0,0 +1,181 @@
+// Copyright 2017 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 go1.8
+
+package promhttp
+
+import (
+ "io"
+ "net/http"
+)
+
+type pusherDelegator struct{ *responseWriterDelegator }
+
+func (d pusherDelegator) Push(target string, opts *http.PushOptions) error {
+ return d.ResponseWriter.(http.Pusher).Push(target, opts)
+}
+
+func init() {
+ pickDelegator[pusher] = func(d *responseWriterDelegator) delegator { // 16
+ return pusherDelegator{d}
+ }
+ pickDelegator[pusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 17
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ http.CloseNotifier
+ }{d, pusherDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[pusher+flusher] = func(d *responseWriterDelegator) delegator { // 18
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ http.Flusher
+ }{d, pusherDelegator{d}, flusherDelegator{d}}
+ }
+ pickDelegator[pusher+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 19
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ http.Flusher
+ http.CloseNotifier
+ }{d, pusherDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[pusher+hijacker] = func(d *responseWriterDelegator) delegator { // 20
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ http.Hijacker
+ }{d, pusherDelegator{d}, hijackerDelegator{d}}
+ }
+ pickDelegator[pusher+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 21
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ http.Hijacker
+ http.CloseNotifier
+ }{d, pusherDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[pusher+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 22
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ http.Hijacker
+ http.Flusher
+ }{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+ }
+ pickDelegator[pusher+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { //23
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ http.Hijacker
+ http.Flusher
+ http.CloseNotifier
+ }{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[pusher+readerFrom] = func(d *responseWriterDelegator) delegator { // 24
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ io.ReaderFrom
+ }{d, pusherDelegator{d}, readerFromDelegator{d}}
+ }
+ pickDelegator[pusher+readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 25
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ io.ReaderFrom
+ http.CloseNotifier
+ }{d, pusherDelegator{d}, readerFromDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[pusher+readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 26
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ io.ReaderFrom
+ http.Flusher
+ }{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}}
+ }
+ pickDelegator[pusher+readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 27
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ io.ReaderFrom
+ http.Flusher
+ http.CloseNotifier
+ }{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[pusher+readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 28
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ io.ReaderFrom
+ http.Hijacker
+ }{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}}
+ }
+ pickDelegator[pusher+readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 29
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ io.ReaderFrom
+ http.Hijacker
+ http.CloseNotifier
+ }{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+ }
+ pickDelegator[pusher+readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 30
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ io.ReaderFrom
+ http.Hijacker
+ http.Flusher
+ }{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+ }
+ pickDelegator[pusher+readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 31
+ return struct {
+ *responseWriterDelegator
+ http.Pusher
+ io.ReaderFrom
+ http.Hijacker
+ http.Flusher
+ http.CloseNotifier
+ }{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+ }
+}
+
+func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator {
+ d := &responseWriterDelegator{
+ ResponseWriter: w,
+ observeWriteHeader: observeWriteHeaderFunc,
+ }
+
+ id := 0
+ if _, ok := w.(http.CloseNotifier); ok {
+ id += closeNotifier
+ }
+ if _, ok := w.(http.Flusher); ok {
+ id += flusher
+ }
+ if _, ok := w.(http.Hijacker); ok {
+ id += hijacker
+ }
+ if _, ok := w.(io.ReaderFrom); ok {
+ id += readerFrom
+ }
+ if _, ok := w.(http.Pusher); ok {
+ id += pusher
+ }
+
+ return pickDelegator[id](d)
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_pre_1_8.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_pre_1_8.go
new file mode 100644
index 0000000..8bb9b8b
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_pre_1_8.go
@@ -0,0 +1,44 @@
+// Copyright 2017 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 !go1.8
+
+package promhttp
+
+import (
+ "io"
+ "net/http"
+)
+
+func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator {
+ d := &responseWriterDelegator{
+ ResponseWriter: w,
+ observeWriteHeader: observeWriteHeaderFunc,
+ }
+
+ id := 0
+ if _, ok := w.(http.CloseNotifier); ok {
+ id += closeNotifier
+ }
+ if _, ok := w.(http.Flusher); ok {
+ id += flusher
+ }
+ if _, ok := w.(http.Hijacker); ok {
+ id += hijacker
+ }
+ if _, ok := w.(io.ReaderFrom); ok {
+ id += readerFrom
+ }
+
+ return pickDelegator[id](d)
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go
new file mode 100644
index 0000000..668eb6b
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go
@@ -0,0 +1,311 @@
+// Copyright 2016 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 promhttp provides tooling around HTTP servers and clients.
+//
+// First, the package allows the creation of http.Handler instances to expose
+// Prometheus metrics via HTTP. promhttp.Handler acts on the
+// prometheus.DefaultGatherer. With HandlerFor, you can create a handler for a
+// custom registry or anything that implements the Gatherer interface. It also
+// allows the creation of handlers that act differently on errors or allow to
+// log errors.
+//
+// Second, the package provides tooling to instrument instances of http.Handler
+// via middleware. Middleware wrappers follow the naming scheme
+// InstrumentHandlerX, where X describes the intended use of the middleware.
+// See each function's doc comment for specific details.
+//
+// Finally, the package allows for an http.RoundTripper to be instrumented via
+// middleware. Middleware wrappers follow the naming scheme
+// InstrumentRoundTripperX, where X describes the intended use of the
+// middleware. See each function's doc comment for specific details.
+package promhttp
+
+import (
+ "compress/gzip"
+ "fmt"
+ "io"
+ "net/http"
+ "strings"
+ "sync"
+ "time"
+
+ "github.com/prometheus/common/expfmt"
+
+ "github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+ contentTypeHeader = "Content-Type"
+ contentLengthHeader = "Content-Length"
+ contentEncodingHeader = "Content-Encoding"
+ acceptEncodingHeader = "Accept-Encoding"
+)
+
+var gzipPool = sync.Pool{
+ New: func() interface{} {
+ return gzip.NewWriter(nil)
+ },
+}
+
+// Handler returns an http.Handler for the prometheus.DefaultGatherer, using
+// default HandlerOpts, i.e. it reports the first error as an HTTP error, it has
+// no error logging, and it applies compression if requested by the client.
+//
+// The returned http.Handler is already instrumented using the
+// InstrumentMetricHandler function and the prometheus.DefaultRegisterer. If you
+// create multiple http.Handlers by separate calls of the Handler function, the
+// metrics used for instrumentation will be shared between them, providing
+// global scrape counts.
+//
+// This function is meant to cover the bulk of basic use cases. If you are doing
+// anything that requires more customization (including using a non-default
+// Gatherer, different instrumentation, and non-default HandlerOpts), use the
+// HandlerFor function. See there for details.
+func Handler() http.Handler {
+ return InstrumentMetricHandler(
+ prometheus.DefaultRegisterer, HandlerFor(prometheus.DefaultGatherer, HandlerOpts{}),
+ )
+}
+
+// HandlerFor returns an uninstrumented http.Handler for the provided
+// Gatherer. The behavior of the Handler is defined by the provided
+// HandlerOpts. Thus, HandlerFor is useful to create http.Handlers for custom
+// Gatherers, with non-default HandlerOpts, and/or with custom (or no)
+// instrumentation. Use the InstrumentMetricHandler function to apply the same
+// kind of instrumentation as it is used by the Handler function.
+func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
+ var inFlightSem chan struct{}
+ if opts.MaxRequestsInFlight > 0 {
+ inFlightSem = make(chan struct{}, opts.MaxRequestsInFlight)
+ }
+
+ h := http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
+ if inFlightSem != nil {
+ select {
+ case inFlightSem <- struct{}{}: // All good, carry on.
+ defer func() { <-inFlightSem }()
+ default:
+ http.Error(rsp, fmt.Sprintf(
+ "Limit of concurrent requests reached (%d), try again later.", opts.MaxRequestsInFlight,
+ ), http.StatusServiceUnavailable)
+ return
+ }
+ }
+ mfs, err := reg.Gather()
+ if err != nil {
+ if opts.ErrorLog != nil {
+ opts.ErrorLog.Println("error gathering metrics:", err)
+ }
+ switch opts.ErrorHandling {
+ case PanicOnError:
+ panic(err)
+ case ContinueOnError:
+ if len(mfs) == 0 {
+ // Still report the error if no metrics have been gathered.
+ httpError(rsp, err)
+ return
+ }
+ case HTTPErrorOnError:
+ httpError(rsp, err)
+ return
+ }
+ }
+
+ contentType := expfmt.Negotiate(req.Header)
+ header := rsp.Header()
+ header.Set(contentTypeHeader, string(contentType))
+
+ w := io.Writer(rsp)
+ if !opts.DisableCompression && 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)
+
+ 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)
+ }
+ switch opts.ErrorHandling {
+ case PanicOnError:
+ panic(err)
+ case ContinueOnError:
+ // Handled later.
+ case HTTPErrorOnError:
+ httpError(rsp, err)
+ return
+ }
+ }
+ }
+
+ if lastErr != nil {
+ httpError(rsp, lastErr)
+ }
+ })
+
+ if opts.Timeout <= 0 {
+ return h
+ }
+ return http.TimeoutHandler(h, opts.Timeout, fmt.Sprintf(
+ "Exceeded configured timeout of %v.\n",
+ opts.Timeout,
+ ))
+}
+
+// InstrumentMetricHandler is usually used with an http.Handler returned by the
+// HandlerFor function. It instruments the provided http.Handler with two
+// metrics: A counter vector "promhttp_metric_handler_requests_total" to count
+// scrapes partitioned by HTTP status code, and a gauge
+// "promhttp_metric_handler_requests_in_flight" to track the number of
+// simultaneous scrapes. This function idempotently registers collectors for
+// both metrics with the provided Registerer. It panics if the registration
+// fails. The provided metrics are useful to see how many scrapes hit the
+// monitored target (which could be from different Prometheus servers or other
+// scrapers), and how often they overlap (which would result in more than one
+// scrape in flight at the same time). Note that the scrapes-in-flight gauge
+// will contain the scrape by which it is exposed, while the scrape counter will
+// only get incremented after the scrape is complete (as only then the status
+// code is known). For tracking scrape durations, use the
+// "scrape_duration_seconds" gauge created by the Prometheus server upon each
+// scrape.
+func InstrumentMetricHandler(reg prometheus.Registerer, handler http.Handler) http.Handler {
+ cnt := prometheus.NewCounterVec(
+ prometheus.CounterOpts{
+ Name: "promhttp_metric_handler_requests_total",
+ Help: "Total number of scrapes by HTTP status code.",
+ },
+ []string{"code"},
+ )
+ // Initialize the most likely HTTP status codes.
+ cnt.WithLabelValues("200")
+ cnt.WithLabelValues("500")
+ cnt.WithLabelValues("503")
+ if err := reg.Register(cnt); err != nil {
+ if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
+ cnt = are.ExistingCollector.(*prometheus.CounterVec)
+ } else {
+ panic(err)
+ }
+ }
+
+ gge := prometheus.NewGauge(prometheus.GaugeOpts{
+ Name: "promhttp_metric_handler_requests_in_flight",
+ Help: "Current number of scrapes being served.",
+ })
+ if err := reg.Register(gge); err != nil {
+ if are, ok := err.(prometheus.AlreadyRegisteredError); ok {
+ gge = are.ExistingCollector.(prometheus.Gauge)
+ } else {
+ panic(err)
+ }
+ }
+
+ return InstrumentHandlerCounter(cnt, InstrumentHandlerInFlight(gge, handler))
+}
+
+// HandlerErrorHandling defines how a Handler serving metrics will handle
+// errors.
+type HandlerErrorHandling int
+
+// These constants cause handlers serving metrics to behave as described if
+// errors are encountered.
+const (
+ // Serve an HTTP status code 500 upon the first error
+ // encountered. Report the error message in the body.
+ 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
+ // last error message in the body. Only use this in deliberate "best
+ // effort" metrics collection scenarios. It is recommended to at least
+ // log errors (by providing an ErrorLog in HandlerOpts) to not mask
+ // errors completely.
+ ContinueOnError
+ // Panic upon the first error encountered (useful for "crash only" apps).
+ PanicOnError
+)
+
+// Logger is the minimal interface HandlerOpts needs for logging. Note that
+// log.Logger from the standard library implements this interface, and it is
+// easy to implement by custom loggers, if they don't do so already anyway.
+type Logger interface {
+ Println(v ...interface{})
+}
+
+// HandlerOpts specifies options how to serve metrics via an http.Handler. The
+// zero value of HandlerOpts is a reasonable default.
+type HandlerOpts struct {
+ // ErrorLog specifies an optional logger for errors collecting and
+ // serving metrics. If nil, errors are not logged at all.
+ ErrorLog Logger
+ // ErrorHandling defines how errors are handled. Note that errors are
+ // logged regardless of the configured ErrorHandling provided ErrorLog
+ // is not nil.
+ ErrorHandling HandlerErrorHandling
+ // If DisableCompression is true, the handler will never compress the
+ // response, even if requested by the client.
+ DisableCompression bool
+ // The number of concurrent HTTP requests is limited to
+ // MaxRequestsInFlight. Additional requests are responded to with 503
+ // Service Unavailable and a suitable message in the body. If
+ // MaxRequestsInFlight is 0 or negative, no limit is applied.
+ MaxRequestsInFlight int
+ // If handling a request takes longer than Timeout, it is responded to
+ // with 503 ServiceUnavailable and a suitable Message. No timeout is
+ // applied if Timeout is 0 or negative. Note that with the current
+ // implementation, reaching the timeout simply ends the HTTP requests as
+ // described above (and even that only if sending of the body hasn't
+ // started yet), while the bulk work of gathering all the metrics keeps
+ // running in the background (with the eventual result to be thrown
+ // away). Until the implementation is improved, it is recommended to
+ // implement a separate timeout in potentially slow Collectors.
+ Timeout time.Duration
+}
+
+// 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,
+ )
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go
new file mode 100644
index 0000000..86fd564
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go
@@ -0,0 +1,97 @@
+// Copyright 2017 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 promhttp
+
+import (
+ "net/http"
+ "time"
+
+ "github.com/prometheus/client_golang/prometheus"
+)
+
+// The RoundTripperFunc type is an adapter to allow the use of ordinary
+// functions as RoundTrippers. If f is a function with the appropriate
+// signature, RountTripperFunc(f) is a RoundTripper that calls f.
+type RoundTripperFunc func(req *http.Request) (*http.Response, error)
+
+// RoundTrip implements the RoundTripper interface.
+func (rt RoundTripperFunc) RoundTrip(r *http.Request) (*http.Response, error) {
+ return rt(r)
+}
+
+// InstrumentRoundTripperInFlight is a middleware that wraps the provided
+// http.RoundTripper. It sets the provided prometheus.Gauge to the number of
+// requests currently handled by the wrapped http.RoundTripper.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperInFlight(gauge prometheus.Gauge, next http.RoundTripper) RoundTripperFunc {
+ return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+ gauge.Inc()
+ defer gauge.Dec()
+ return next.RoundTrip(r)
+ })
+}
+
+// InstrumentRoundTripperCounter is a middleware that wraps the provided
+// http.RoundTripper to observe the request result with the provided CounterVec.
+// The CounterVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. Partitioning of the CounterVec happens by HTTP status code
+// and/or HTTP method if the respective instance label names are present in the
+// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
+//
+// If the wrapped RoundTripper panics or returns a non-nil error, the Counter
+// is not incremented.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperCounter(counter *prometheus.CounterVec, next http.RoundTripper) RoundTripperFunc {
+ code, method := checkLabels(counter)
+
+ return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+ resp, err := next.RoundTrip(r)
+ if err == nil {
+ counter.With(labels(code, method, r.Method, resp.StatusCode)).Inc()
+ }
+ return resp, err
+ })
+}
+
+// InstrumentRoundTripperDuration is a middleware that wraps the provided
+// http.RoundTripper to observe the request duration with the provided
+// ObserverVec. The ObserverVec must have zero, one, or two non-const
+// non-curried labels. For those, the only allowed label names are "code" and
+// "method". The function panics otherwise. The Observe method of the Observer
+// in the ObserverVec is called with the request duration in
+// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
+// respective instance label names are present in the ObserverVec. For
+// unpartitioned observations, use an ObserverVec with zero labels. Note that
+// partitioning of Histograms is expensive and should be used judiciously.
+//
+// If the wrapped RoundTripper panics or returns a non-nil error, no values are
+// reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func InstrumentRoundTripperDuration(obs prometheus.ObserverVec, next http.RoundTripper) RoundTripperFunc {
+ code, method := checkLabels(obs)
+
+ return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+ start := time.Now()
+ resp, err := next.RoundTrip(r)
+ if err == nil {
+ obs.With(labels(code, method, r.Method, resp.StatusCode)).Observe(time.Since(start).Seconds())
+ }
+ return resp, err
+ })
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client_1_8.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client_1_8.go
new file mode 100644
index 0000000..a034d1e
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client_1_8.go
@@ -0,0 +1,144 @@
+// Copyright 2017 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 go1.8
+
+package promhttp
+
+import (
+ "context"
+ "crypto/tls"
+ "net/http"
+ "net/http/httptrace"
+ "time"
+)
+
+// InstrumentTrace is used to offer flexibility in instrumenting the available
+// httptrace.ClientTrace hook functions. Each function is passed a float64
+// representing the time in seconds since the start of the http request. A user
+// may choose to use separately buckets Histograms, or implement custom
+// instance labels on a per function basis.
+type InstrumentTrace struct {
+ GotConn func(float64)
+ PutIdleConn func(float64)
+ GotFirstResponseByte func(float64)
+ Got100Continue func(float64)
+ DNSStart func(float64)
+ DNSDone func(float64)
+ ConnectStart func(float64)
+ ConnectDone func(float64)
+ TLSHandshakeStart func(float64)
+ TLSHandshakeDone func(float64)
+ WroteHeaders func(float64)
+ Wait100Continue func(float64)
+ WroteRequest func(float64)
+}
+
+// InstrumentRoundTripperTrace is a middleware that wraps the provided
+// RoundTripper and reports times to hook functions provided in the
+// InstrumentTrace struct. Hook functions that are not present in the provided
+// InstrumentTrace struct are ignored. Times reported to the hook functions are
+// time since the start of the request. Only with Go1.9+, those times are
+// guaranteed to never be negative. (Earlier Go versions are not using a
+// monotonic clock.) Note that partitioning of Histograms is expensive and
+// should be used judiciously.
+//
+// For hook functions that receive an error as an argument, no observations are
+// made in the event of a non-nil error value.
+//
+// See the example for ExampleInstrumentRoundTripperDuration for example usage.
+func InstrumentRoundTripperTrace(it *InstrumentTrace, next http.RoundTripper) RoundTripperFunc {
+ return RoundTripperFunc(func(r *http.Request) (*http.Response, error) {
+ start := time.Now()
+
+ trace := &httptrace.ClientTrace{
+ GotConn: func(_ httptrace.GotConnInfo) {
+ if it.GotConn != nil {
+ it.GotConn(time.Since(start).Seconds())
+ }
+ },
+ PutIdleConn: func(err error) {
+ if err != nil {
+ return
+ }
+ if it.PutIdleConn != nil {
+ it.PutIdleConn(time.Since(start).Seconds())
+ }
+ },
+ DNSStart: func(_ httptrace.DNSStartInfo) {
+ if it.DNSStart != nil {
+ it.DNSStart(time.Since(start).Seconds())
+ }
+ },
+ DNSDone: func(_ httptrace.DNSDoneInfo) {
+ if it.DNSDone != nil {
+ it.DNSDone(time.Since(start).Seconds())
+ }
+ },
+ ConnectStart: func(_, _ string) {
+ if it.ConnectStart != nil {
+ it.ConnectStart(time.Since(start).Seconds())
+ }
+ },
+ ConnectDone: func(_, _ string, err error) {
+ if err != nil {
+ return
+ }
+ if it.ConnectDone != nil {
+ it.ConnectDone(time.Since(start).Seconds())
+ }
+ },
+ GotFirstResponseByte: func() {
+ if it.GotFirstResponseByte != nil {
+ it.GotFirstResponseByte(time.Since(start).Seconds())
+ }
+ },
+ Got100Continue: func() {
+ if it.Got100Continue != nil {
+ it.Got100Continue(time.Since(start).Seconds())
+ }
+ },
+ TLSHandshakeStart: func() {
+ if it.TLSHandshakeStart != nil {
+ it.TLSHandshakeStart(time.Since(start).Seconds())
+ }
+ },
+ TLSHandshakeDone: func(_ tls.ConnectionState, err error) {
+ if err != nil {
+ return
+ }
+ if it.TLSHandshakeDone != nil {
+ it.TLSHandshakeDone(time.Since(start).Seconds())
+ }
+ },
+ WroteHeaders: func() {
+ if it.WroteHeaders != nil {
+ it.WroteHeaders(time.Since(start).Seconds())
+ }
+ },
+ Wait100Continue: func() {
+ if it.Wait100Continue != nil {
+ it.Wait100Continue(time.Since(start).Seconds())
+ }
+ },
+ WroteRequest: func(_ httptrace.WroteRequestInfo) {
+ if it.WroteRequest != nil {
+ it.WroteRequest(time.Since(start).Seconds())
+ }
+ },
+ }
+ r = r.WithContext(httptrace.WithClientTrace(context.Background(), trace))
+
+ return next.RoundTrip(r)
+ })
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go
new file mode 100644
index 0000000..9db2438
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go
@@ -0,0 +1,447 @@
+// Copyright 2017 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 promhttp
+
+import (
+ "errors"
+ "net/http"
+ "strconv"
+ "strings"
+ "time"
+
+ dto "github.com/prometheus/client_model/go"
+
+ "github.com/prometheus/client_golang/prometheus"
+)
+
+// magicString is used for the hacky label test in checkLabels. Remove once fixed.
+const magicString = "zZgWfBxLqvG8kc8IMv3POi2Bb0tZI3vAnBx+gBaFi9FyPzB/CzKUer1yufDa"
+
+// InstrumentHandlerInFlight is a middleware that wraps the provided
+// http.Handler. It sets the provided prometheus.Gauge to the number of
+// requests currently handled by the wrapped http.Handler.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerInFlight(g prometheus.Gauge, next http.Handler) http.Handler {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ g.Inc()
+ defer g.Dec()
+ next.ServeHTTP(w, r)
+ })
+}
+
+// InstrumentHandlerDuration is a middleware that wraps the provided
+// http.Handler to observe the request duration with the provided ObserverVec.
+// The ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the request duration in seconds. Partitioning happens by HTTP
+// status code and/or HTTP method if the respective instance label names are
+// present in the ObserverVec. For unpartitioned observations, use an
+// ObserverVec with zero labels. Note that partitioning of Histograms is
+// expensive and should be used judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+func InstrumentHandlerDuration(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+ code, method := checkLabels(obs)
+
+ if code {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ now := time.Now()
+ d := newDelegator(w, nil)
+ next.ServeHTTP(d, r)
+
+ obs.With(labels(code, method, r.Method, d.Status())).Observe(time.Since(now).Seconds())
+ })
+ }
+
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ now := time.Now()
+ next.ServeHTTP(w, r)
+ obs.With(labels(code, method, r.Method, 0)).Observe(time.Since(now).Seconds())
+ })
+}
+
+// InstrumentHandlerCounter is a middleware that wraps the provided http.Handler
+// to observe the request result with the provided CounterVec. The CounterVec
+// must have zero, one, or two non-const non-curried labels. For those, the only
+// allowed label names are "code" and "method". The function panics
+// otherwise. Partitioning of the CounterVec happens by HTTP status code and/or
+// HTTP method if the respective instance label names are present in the
+// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, the Counter is not incremented.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler) http.HandlerFunc {
+ code, method := checkLabels(counter)
+
+ if code {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ d := newDelegator(w, nil)
+ next.ServeHTTP(d, r)
+ counter.With(labels(code, method, r.Method, d.Status())).Inc()
+ })
+ }
+
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ next.ServeHTTP(w, r)
+ counter.With(labels(code, method, r.Method, 0)).Inc()
+ })
+}
+
+// InstrumentHandlerTimeToWriteHeader is a middleware that wraps the provided
+// http.Handler to observe with the provided ObserverVec the request duration
+// until the response headers are written. The ObserverVec must have zero, one,
+// or two non-const non-curried labels. For those, the only allowed label names
+// are "code" and "method". The function panics otherwise. The Observe method of
+// the Observer in the ObserverVec is called with the request duration in
+// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
+// respective instance label names are present in the ObserverVec. For
+// unpartitioned observations, use an ObserverVec with zero labels. Note that
+// partitioning of Histograms is expensive and should be used judiciously.
+//
+// If the wrapped Handler panics before calling WriteHeader, no value is
+// reported.
+//
+// Note that this method is only guaranteed to never observe negative durations
+// if used with Go1.9+.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerTimeToWriteHeader(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+ code, method := checkLabels(obs)
+
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ now := time.Now()
+ d := newDelegator(w, func(status int) {
+ obs.With(labels(code, method, r.Method, status)).Observe(time.Since(now).Seconds())
+ })
+ next.ServeHTTP(d, r)
+ })
+}
+
+// InstrumentHandlerRequestSize is a middleware that wraps the provided
+// http.Handler to observe the request size with the provided ObserverVec. The
+// ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the request size in bytes. Partitioning happens by HTTP status
+// code and/or HTTP method if the respective instance label names are present in
+// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
+// labels. Note that partitioning of Histograms is expensive and should be used
+// judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerRequestSize(obs prometheus.ObserverVec, next http.Handler) http.HandlerFunc {
+ code, method := checkLabels(obs)
+
+ if code {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ d := newDelegator(w, nil)
+ next.ServeHTTP(d, r)
+ size := computeApproximateRequestSize(r)
+ obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(size))
+ })
+ }
+
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ next.ServeHTTP(w, r)
+ size := computeApproximateRequestSize(r)
+ obs.With(labels(code, method, r.Method, 0)).Observe(float64(size))
+ })
+}
+
+// InstrumentHandlerResponseSize is a middleware that wraps the provided
+// http.Handler to observe the response size with the provided ObserverVec. The
+// ObserverVec must have zero, one, or two non-const non-curried labels. For
+// those, the only allowed label names are "code" and "method". The function
+// panics otherwise. The Observe method of the Observer in the ObserverVec is
+// called with the response size in bytes. Partitioning happens by HTTP status
+// code and/or HTTP method if the respective instance label names are present in
+// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
+// labels. Note that partitioning of Histograms is expensive and should be used
+// judiciously.
+//
+// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
+//
+// If the wrapped Handler panics, no values are reported.
+//
+// See the example for InstrumentHandlerDuration for example usage.
+func InstrumentHandlerResponseSize(obs prometheus.ObserverVec, next http.Handler) http.Handler {
+ code, method := checkLabels(obs)
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ d := newDelegator(w, nil)
+ next.ServeHTTP(d, r)
+ obs.With(labels(code, method, r.Method, d.Status())).Observe(float64(d.Written()))
+ })
+}
+
+func checkLabels(c prometheus.Collector) (code bool, method bool) {
+ // TODO(beorn7): Remove this hacky way to check for instance labels
+ // once Descriptors can have their dimensionality queried.
+ var (
+ desc *prometheus.Desc
+ m prometheus.Metric
+ pm dto.Metric
+ lvs []string
+ )
+
+ // Get the Desc from the Collector.
+ descc := make(chan *prometheus.Desc, 1)
+ c.Describe(descc)
+
+ select {
+ case desc = <-descc:
+ default:
+ panic("no description provided by collector")
+ }
+ select {
+ case <-descc:
+ panic("more than one description provided by collector")
+ default:
+ }
+
+ close(descc)
+
+ // Create a ConstMetric with the Desc. Since we don't know how many
+ // variable labels there are, try for as long as it needs.
+ for err := errors.New("dummy"); err != nil; lvs = append(lvs, magicString) {
+ m, err = prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, lvs...)
+ }
+
+ // Write out the metric into a proto message and look at the labels.
+ // If the value is not the magicString, it is a constLabel, which doesn't interest us.
+ // If the label is curried, it doesn't interest us.
+ // In all other cases, only "code" or "method" is allowed.
+ if err := m.Write(&pm); err != nil {
+ panic("error checking metric for labels")
+ }
+ for _, label := range pm.Label {
+ name, value := label.GetName(), label.GetValue()
+ if value != magicString || isLabelCurried(c, name) {
+ continue
+ }
+ switch name {
+ case "code":
+ code = true
+ case "method":
+ method = true
+ default:
+ panic("metric partitioned with non-supported labels")
+ }
+ }
+ return
+}
+
+func isLabelCurried(c prometheus.Collector, label string) bool {
+ // This is even hackier than the label test above.
+ // We essentially try to curry again and see if it works.
+ // But for that, we need to type-convert to the two
+ // types we use here, ObserverVec or *CounterVec.
+ switch v := c.(type) {
+ case *prometheus.CounterVec:
+ if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
+ return false
+ }
+ case prometheus.ObserverVec:
+ if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
+ return false
+ }
+ default:
+ panic("unsupported metric vec type")
+ }
+ return true
+}
+
+// emptyLabels is a one-time allocation for non-partitioned metrics to avoid
+// unnecessary allocations on each request.
+var emptyLabels = prometheus.Labels{}
+
+func labels(code, method bool, reqMethod string, status int) prometheus.Labels {
+ if !(code || method) {
+ return emptyLabels
+ }
+ labels := prometheus.Labels{}
+
+ if code {
+ labels["code"] = sanitizeCode(status)
+ }
+ if method {
+ labels["method"] = sanitizeMethod(reqMethod)
+ }
+
+ return labels
+}
+
+func computeApproximateRequestSize(r *http.Request) int {
+ s := 0
+ if r.URL != nil {
+ s += len(r.URL.String())
+ }
+
+ 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)
+ }
+ return s
+}
+
+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)
+ }
+}
+
+// If the wrapped http.Handler has not set a status code, i.e. the value is
+// currently 0, santizeCode will return 200, for consistency with behavior in
+// the stdlib.
+func sanitizeCode(s int) string {
+ switch s {
+ case 100:
+ return "100"
+ case 101:
+ return "101"
+
+ case 200, 0:
+ 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)
+ }
+}
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 835866a..1f43d12 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -16,6 +16,7 @@ github.com/howeyc/fsnotify
github.com/matttproud/golang_protobuf_extensions/pbutil
# github.com/prometheus/client_golang v0.9.2
github.com/prometheus/client_golang/prometheus
+github.com/prometheus/client_golang/prometheus/promhttp
github.com/prometheus/client_golang/prometheus/internal
# github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910
github.com/prometheus/client_model/go