From 1a16aa4889607c739991fa01fbfb7b26f75a9c44 Mon Sep 17 00:00:00 2001
From: IvoGoman <ivo.gosemann@sap.com>
Date: Wed, 18 Sep 2024 00:01:57 +0200
Subject: [PATCH] feat(metrics): add response_size, request_duration histograms
(#3748)
replaces felixge/httpsnoop with prometheus/client_golang instrumentation
adds histograms for response_size_bytes & request_duration_seconds
Signed-off-by: Ivo Gosemann <ivo.gosemann@sap.com>
---
go.mod | 2 +-
server/server.go | 41 +++++++++++++++++++++++++----------------
2 files changed, 26 insertions(+), 17 deletions(-)
diff --git a/go.mod b/go.mod
index 50774ab8..8e619d7b 100644
--- a/go.mod
+++ b/go.mod
@@ -11,7 +11,6 @@ require (
github.com/beevik/etree v1.4.0
github.com/coreos/go-oidc/v3 v3.11.0
github.com/dexidp/dex/api/v2 v2.1.0
- github.com/felixge/httpsnoop v1.0.4
github.com/fsnotify/fsnotify v1.7.0
github.com/ghodss/yaml v1.0.0
github.com/go-jose/go-jose/v4 v4.0.4
@@ -57,6 +56,7 @@ require (
github.com/coreos/go-semver v0.3.0 // indirect
github.com/coreos/go-systemd/v22 v22.3.2 // indirect
github.com/davecgh/go-spew v1.1.1 // indirect
+ github.com/felixge/httpsnoop v1.0.4 // indirect
github.com/go-asn1-ber/asn1-ber v1.5.5 // indirect
github.com/go-logr/logr v1.4.2 // indirect
github.com/go-logr/stdr v1.2.2 // indirect
diff --git a/server/server.go b/server/server.go
index 1cf71c50..e299e32f 100644
--- a/server/server.go
+++ b/server/server.go
@@ -15,18 +15,17 @@ import (
"os"
"path"
"sort"
- "strconv"
"strings"
"sync"
"sync/atomic"
"time"
gosundheit "github.com/AppsFlyer/go-sundheit"
- "github.com/felixge/httpsnoop"
"github.com/google/uuid"
"github.com/gorilla/handlers"
"github.com/gorilla/mux"
"github.com/prometheus/client_golang/prometheus"
+ "github.com/prometheus/client_golang/prometheus/promhttp"
"golang.org/x/crypto/bcrypt"
"github.com/dexidp/dex/connector"
@@ -332,7 +331,7 @@ func newServer(ctx context.Context, c Config, rotationStrategy rotationStrategy)
}
}
- instrumentHandlerCounter := func(_ string, handler http.Handler) http.HandlerFunc {
+ instrumentHandler := func(_ string, handler http.Handler) http.HandlerFunc {
return handler.ServeHTTP
}
@@ -340,18 +339,28 @@ func newServer(ctx context.Context, c Config, rotationStrategy rotationStrategy)
requestCounter := prometheus.NewCounterVec(prometheus.CounterOpts{
Name: "http_requests_total",
Help: "Count of all HTTP requests.",
- }, []string{"handler", "code", "method"})
-
- err = c.PrometheusRegistry.Register(requestCounter)
- if err != nil {
- return nil, fmt.Errorf("server: Failed to register Prometheus HTTP metrics: %v", err)
- }
-
- instrumentHandlerCounter = func(handlerName string, handler http.Handler) http.HandlerFunc {
- return func(w http.ResponseWriter, r *http.Request) {
- m := httpsnoop.CaptureMetrics(handler, w, r)
- requestCounter.With(prometheus.Labels{"handler": handlerName, "code": strconv.Itoa(m.Code), "method": r.Method}).Inc()
- }
+ }, []string{"code", "method", "handler"})
+
+ durationHist := prometheus.NewHistogramVec(prometheus.HistogramOpts{
+ Name: "request_duration_seconds",
+ Help: "A histogram of latencies for requests.",
+ Buckets: []float64{.25, .5, 1, 2.5, 5, 10},
+ }, []string{"code", "method", "handler"})
+
+ sizeHist := prometheus.NewHistogramVec(prometheus.HistogramOpts{
+ Name: "response_size_bytes",
+ Help: "A histogram of response sizes for requests.",
+ Buckets: []float64{200, 500, 900, 1500},
+ }, []string{"code", "method", "handler"})
+
+ c.PrometheusRegistry.MustRegister(requestCounter, durationHist, sizeHist)
+
+ instrumentHandler = func(handlerName string, handler http.Handler) http.HandlerFunc {
+ return promhttp.InstrumentHandlerDuration(durationHist.MustCurryWith(prometheus.Labels{"handler": handlerName}),
+ promhttp.InstrumentHandlerCounter(requestCounter.MustCurryWith(prometheus.Labels{"handler": handlerName}),
+ promhttp.InstrumentHandlerResponseSize(sizeHist.MustCurryWith(prometheus.Labels{"handler": handlerName}), handler),
+ ),
+ )
}
}
@@ -401,7 +410,7 @@ func newServer(ctx context.Context, c Config, rotationStrategy rotationStrategy)
}
r = r.WithContext(rCtx)
- instrumentHandlerCounter(handlerName, handler)(w, r)
+ instrumentHandler(handlerName, handler)(w, r)
}
}
--
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