diff options
Diffstat (limited to 'vendor/github.com/prometheus/client_golang/prometheus/promhttp')
6 files changed, 220 insertions, 107 deletions
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go index 5ee095b..9c1c66d 100644 --- a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go @@ -102,10 +102,10 @@ func init() { return d } pickDelegator[closeNotifier] = func(d *responseWriterDelegator) delegator { // 1 - return closeNotifierDelegator{d} + return &closeNotifierDelegator{d} } pickDelegator[flusher] = func(d *responseWriterDelegator) delegator { // 2 - return flusherDelegator{d} + return &flusherDelegator{d} } pickDelegator[flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 3 return struct { @@ -115,7 +115,7 @@ func init() { }{d, &flusherDelegator{d}, &closeNotifierDelegator{d}} } pickDelegator[hijacker] = func(d *responseWriterDelegator) delegator { // 4 - return hijackerDelegator{d} + return &hijackerDelegator{d} } pickDelegator[hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 5 return struct { 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 index f4d386f..75a905e 100644 --- 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 @@ -28,7 +28,7 @@ func (d *pusherDelegator) Push(target string, opts *http.PushOptions) error { func init() { pickDelegator[pusher] = func(d *responseWriterDelegator) delegator { // 16 - return pusherDelegator{d} + return &pusherDelegator{d} } pickDelegator[pusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 17 return struct { diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go index 2d67f24..0135737 100644 --- a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go @@ -39,6 +39,7 @@ import ( "net/http" "strings" "sync" + "time" "github.com/prometheus/common/expfmt" @@ -67,21 +68,51 @@ func giveBuf(buf *bytes.Buffer) { bufPool.Put(buf) } -// Handler returns an HTTP handler for the prometheus.DefaultGatherer. The -// Handler uses the default HandlerOpts, i.e. report the first error as an HTTP -// error, no error logging, and compression if requested by the client. +// 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. // -// If you want to create a Handler for the DefaultGatherer with different -// HandlerOpts, create it with HandlerFor with prometheus.DefaultGatherer and -// your desired HandlerOpts. +// 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 HandlerFor(prometheus.DefaultGatherer, HandlerOpts{}) + return InstrumentMetricHandler( + prometheus.DefaultRegisterer, HandlerFor(prometheus.DefaultGatherer, HandlerOpts{}), + ) } -// HandlerFor returns an http.Handler for the provided Gatherer. The behavior -// of the Handler is defined by the provided 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 { - return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) { + var inFlightSem chan struct{} + if opts.MaxRequestsInFlight > 0 { + inFlightSem = make(chan struct{}, opts.MaxRequestsInFlight) + } + + h := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) { + if inFlightSem != nil { + select { + case inFlightSem <- struct{}{}: // All good, carry on. + defer func() { <-inFlightSem }() + default: + http.Error(w, 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 { @@ -137,9 +168,70 @@ func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler { if encoding != "" { header.Set(contentEncodingHeader, encoding) } - w.Write(buf.Bytes()) + if _, err := w.Write(buf.Bytes()); err != nil && opts.ErrorLog != nil { + opts.ErrorLog.Println("error while sending encoded metrics:", err) + } // TODO(beorn7): Consider streaming serving of metrics. }) + + 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 @@ -183,6 +275,21 @@ type HandlerOpts struct { // 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 } // decorateWriter wraps a writer to handle gzip compression if requested. It @@ -195,7 +302,7 @@ func decorateWriter(request *http.Request, writer io.Writer, compressionDisabled header := request.Header.Get(acceptEncodingHeader) parts := strings.Split(header, ",") for _, part := range parts { - part := strings.TrimSpace(part) + part = strings.TrimSpace(part) if part == "gzip" || strings.HasPrefix(part, "gzip;") { return gzip.NewWriter(writer), "gzip" } 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 index 65f9425..86fd564 100644 --- a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_client.go @@ -45,12 +45,11 @@ func InstrumentRoundTripperInFlight(gauge prometheus.Gauge, next http.RoundTripp // 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 labels. The only allowed label -// names are "code" and "method". The function panics if any other instance -// labels are provided. 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. +// 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. @@ -69,15 +68,15 @@ func InstrumentRoundTripperCounter(counter *prometheus.CounterVec, next http.Rou } // 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 labels. The only allowed label -// names are "code" and "method". The function panics if any other instance -// labels are provided. 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. +// 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. 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 index 0bd80c3..a034d1e 100644 --- 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 @@ -81,8 +81,8 @@ func InstrumentRoundTripperTrace(it *InstrumentTrace, next http.RoundTripper) Ro } }, DNSDone: func(_ httptrace.DNSDoneInfo) { - if it.DNSStart != nil { - it.DNSStart(time.Since(start).Seconds()) + if it.DNSDone != nil { + it.DNSDone(time.Since(start).Seconds()) } }, ConnectStart: func(_, _ string) { 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 index 3d145ad..9db2438 100644 --- a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go @@ -14,6 +14,7 @@ package promhttp import ( + "errors" "net/http" "strconv" "strings" @@ -42,10 +43,10 @@ func InstrumentHandlerInFlight(g prometheus.Gauge, next http.Handler) http.Handl // 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 labels. The only allowed label -// names are "code" and "method". The function panics if any other instance -// labels are provided. The Observe method of the Observer in the ObserverVec -// is called with the request duration in seconds. Partitioning happens by HTTP +// 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 @@ -77,14 +78,13 @@ func InstrumentHandlerDuration(obs prometheus.ObserverVec, next http.Handler) ht }) } -// 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 labels. The only allowed label -// names are "code" and "method". The function panics if any other instance -// labels are provided. 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. +// 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. // @@ -111,14 +111,13 @@ func InstrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler) // 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 labels. The only allowed label names are "code" and "method". The -// function panics if any other instance labels are provided. 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. +// 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. @@ -140,15 +139,15 @@ func InstrumentHandlerTimeToWriteHeader(obs prometheus.ObserverVec, next http.Ha } // 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 labels. The only allowed label -// names are "code" and "method". The function panics if any other instance -// labels are provided. 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. +// 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. // @@ -175,15 +174,15 @@ func InstrumentHandlerRequestSize(obs prometheus.ObserverVec, next http.Handler) } // 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 labels. The only allowed label -// names are "code" and "method". The function panics if any other instance -// labels are provided. 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. +// 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. // @@ -204,9 +203,12 @@ func checkLabels(c prometheus.Collector) (code bool, method bool) { // 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) @@ -223,49 +225,54 @@ func checkLabels(c prometheus.Collector) (code bool, method bool) { close(descc) - if _, err := prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0); err == nil { - return + // 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") } - if m, err := prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, magicString); err == nil { - 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 } - for _, label := range pm.Label { - name, value := label.GetName(), label.GetValue() - if value != magicString { - continue - } - switch name { - case "code": - code = true - case "method": - method = true - default: - panic("metric partitioned with non-supported labels") - } - return + switch name { + case "code": + code = true + case "method": + method = true + default: + panic("metric partitioned with non-supported labels") } - panic("previously set label not found – this must never happen") } - if m, err := prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, magicString, magicString); err == nil { - if err := m.Write(&pm); err != nil { - panic("error checking metric for 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 } - for _, label := range pm.Label { - name, value := label.GetName(), label.GetValue() - if value != magicString { - continue - } - if name == "code" || name == "method" { - continue - } - panic("metric partitioned with non-supported labels") + case prometheus.ObserverVec: + if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil { + return false } - code = true - method = true - return + default: + panic("unsupported metric vec type") } - panic("metric partitioned with non-supported labels") + return true } // emptyLabels is a one-time allocation for non-partitioned metrics to avoid |