44 lines
1.4 KiB
Go
44 lines
1.4 KiB
Go
package middleware
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import (
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"net/http"
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"github.com/prometheus/client_golang/prometheus"
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"github.com/prometheus/client_golang/prometheus/promhttp"
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)
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var (
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requestCounter = prometheus.NewCounterVec(
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prometheus.CounterOpts{
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Name: "handler_requests_total",
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Help: "Total number of request/responses by HTTP status code.",
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}, []string{"handler", "code"})
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requestDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
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Name: "handler_request_duration",
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Help: "Handler request duration.",
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}, []string{"handler", "method"})
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requestInFlight = prometheus.NewGaugeVec(prometheus.GaugeOpts{
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Name: "handler_requests_in_flight",
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Help: "Current number of requests being served.",
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}, []string{"handler"})
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)
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func init() {
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_ = prometheus.Register(requestCounter)
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_ = prometheus.Register(requestDuration)
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_ = prometheus.Register(requestInFlight)
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}
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// Metrics captures request duration, request count and in-flight request count
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// metrics for HTTP handlers. The family field is used to discriminate handlers.
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func Metrics(family string, next http.Handler) http.Handler {
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return promhttp.InstrumentHandlerDuration(
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requestDuration.MustCurryWith(prometheus.Labels{"handler": family}),
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promhttp.InstrumentHandlerCounter(requestCounter.MustCurryWith(prometheus.Labels{"handler": family}),
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promhttp.InstrumentHandlerInFlight(requestInFlight.With(prometheus.Labels{"handler": family}), next),
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),
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)
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}
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