diff options
Diffstat (limited to 'modules/caddyhttp/metrics.go')
| -rw-r--r-- | modules/caddyhttp/metrics.go | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/modules/caddyhttp/metrics.go b/modules/caddyhttp/metrics.go index 3e5d6396e..8aa91846c 100644 --- a/modules/caddyhttp/metrics.go +++ b/modules/caddyhttp/metrics.go @@ -4,7 +4,6 @@ import ( "context" "net/http" "strconv" - "strings" "sync" "time" @@ -109,7 +108,7 @@ func newMetricsInstrumentedHandler(handler string, mh MiddlewareHandler) *metric func (h *metricsInstrumentedHandler) ServeHTTP(w http.ResponseWriter, r *http.Request, next Handler) error { server := serverNameFromContext(r.Context()) labels := prometheus.Labels{"server": server, "handler": h.handler} - method := strings.ToUpper(r.Method) + method := sanitizeMethod(r.Method) // the "code" value is set later, but initialized here to eliminate the possibility // of a panic statusLabels := prometheus.Labels{"server": server, "handler": h.handler, "method": method, "code": ""} @@ -160,6 +159,30 @@ func sanitizeCode(code int) string { return strconv.Itoa(code) } +// Only support the list of "regular" HTTP methods, see +// https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods +var methodMap = map[string]string{ + "GET": http.MethodGet, "get": http.MethodGet, + "HEAD": http.MethodHead, "head": http.MethodHead, + "PUT": http.MethodPut, "put": http.MethodPut, + "POST": http.MethodPost, "post": http.MethodPost, + "DELETE": http.MethodDelete, "delete": http.MethodDelete, + "CONNECT": http.MethodConnect, "connect": http.MethodConnect, + "OPTIONS": http.MethodOptions, "options": http.MethodOptions, + "TRACE": http.MethodTrace, "trace": http.MethodTrace, + "PATCH": http.MethodPatch, "patch": http.MethodPatch, +} + +// sanitizeMethod sanitizes the method for use as a metric label. This helps +// prevent high cardinality on the method label. The name is always upper case. +func sanitizeMethod(m string) string { + if m, ok := methodMap[m]; ok { + return m + } + + return "other" +} + // taken from https://github.com/prometheus/client_golang/blob/6007b2b5cae01203111de55f753e76d8dac1f529/prometheus/promhttp/instrument_server.go#L298 func computeApproximateRequestSize(r *http.Request) int { s := 0 |