fix(metrics): fallback to legacy naming

go.mod

@@ -46,6 +46,7 @@ require (
 	github.com/emirpasic/gods v1.18.1
 	github.com/ethantkoenig/rupture v1.0.1
 	github.com/felixge/fgprof v0.9.5
+	github.com/felixge/httpsnoop v1.0.4
 	github.com/fsnotify/fsnotify v1.7.0
 	github.com/gliderlabs/ssh v0.3.8
 	github.com/go-ap/activitypub v0.0.0-20240910141749-b4b8c8aa484c
@@ -99,6 +100,7 @@ require (
 	github.com/pkg/errors v0.9.1
 	github.com/pquerna/otp v1.4.0
 	github.com/prometheus/client_golang v1.20.5
+	github.com/prometheus/common v0.60.1
 	github.com/quasoft/websspi v1.1.2
 	github.com/redis/go-redis/v9 v9.7.0
 	github.com/robfig/cron/v3 v3.0.1
@@ -193,7 +195,6 @@ require (
 	github.com/dlclark/regexp2 v1.11.4 // indirect
 	github.com/emersion/go-sasl v0.0.0-20241020182733-b788ff22d5a6 // indirect
 	github.com/fatih/color v1.18.0 // indirect
-	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/fxamacker/cbor/v2 v2.7.0 // indirect
 	github.com/git-lfs/pktline v0.0.0-20230103162542-ca444d533ef1 // indirect
 	github.com/go-ap/errors v0.0.0-20240910140019-1e9d33cc1568 // indirect
@@ -268,7 +269,6 @@ require (
 	github.com/pjbgf/sha1cd v0.3.1 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/prometheus/client_model v0.6.1 // indirect
-	github.com/prometheus/common v0.60.1 // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect
 	github.com/rhysd/actionlint v1.7.3 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect

routers/common/middleware.go

@@ -24,35 +24,41 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promauto"
 )
 
+const (
+	httpRequestMethod      = "http_request_method"
+	httpResponseStatusCode = "http_response_status_code"
+	httpRoute              = "http_route"
+)
+
 var (
 	// reqInflightGauge tracks the amount of currently handled requests
 	reqInflightGauge = promauto.NewGaugeVec(prometheus.GaugeOpts{
 		Namespace: "http",
 		Subsystem: "server",
 		Name:      "active_requests",
 		Help:      "Number of active HTTP server requests.",
-	}, []string{"http.request.method"})
+	}, []string{httpRequestMethod})
 	// reqDurationHistogram tracks the time taken by http request
 	reqDurationHistogram = promauto.NewHistogramVec(prometheus.HistogramOpts{
 		Namespace: "http",
 		Subsystem: "server",
 		Name:      "request_duration",
 		Help:      "Measures the latency of HTTP requests processed by the server",
-	}, []string{"http.request.method", "http.response.status_code", "http.route"})
+	}, []string{httpRequestMethod, httpResponseStatusCode, httpRoute})
 	// reqSizeHistogram tracks the size of request
 	reqSizeHistogram = promauto.NewHistogramVec(prometheus.HistogramOpts{
 		Namespace: "http",
 		Subsystem: "server_request",
 		Name:      "body_size",
 		Help:      "Size of HTTP server request bodies.",
-	}, []string{"http.request.method", "http.response.status_code", "http.route"})
+	}, []string{httpRequestMethod, httpResponseStatusCode, httpRoute})
 	// respSizeHistogram tracks the size of the response
 	respSizeHistogram = promauto.NewHistogramVec(prometheus.HistogramOpts{
 		Namespace: "http",
 		Subsystem: "server_response",
 		Name:      "body_size",
 		Help:      "Size of HTTP server response bodies.",
-	}, []string{"http.request.method", "http.response.status_code", "http.route"})
+	}, []string{httpRequestMethod, httpResponseStatusCode, httpRoute})
 )
 
 // ProtocolMiddlewares returns HTTP protocol related middlewares, and it provides a global panic recovery