diff options
| -rw-r--r-- | internal/metrics/metrics.go | 39 | ||||
| -rw-r--r-- | internal/metrics/metrics_test.go | 28 | ||||
| -rw-r--r-- | metrics.go | 16 | ||||
| -rw-r--r-- | modules/caddyhttp/metrics.go | 16 |
4 files changed, 74 insertions, 25 deletions
diff --git a/internal/metrics/metrics.go b/internal/metrics/metrics.go new file mode 100644 index 0000000..7ae09b6 --- /dev/null +++ b/internal/metrics/metrics.go @@ -0,0 +1,39 @@ +package metrics + +import ( + "net/http" + "strconv" +) + +func SanitizeCode(s int) string { + switch s { + case 0, 200: + return "200" + default: + return strconv.Itoa(s) + } +} + +// 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" +} diff --git a/internal/metrics/metrics_test.go b/internal/metrics/metrics_test.go new file mode 100644 index 0000000..c3f5965 --- /dev/null +++ b/internal/metrics/metrics_test.go @@ -0,0 +1,28 @@ +package metrics + +import ( + "strings" + "testing" +) + +func TestSanitizeMethod(t *testing.T) { + tests := []struct { + method string + expected string + }{ + {method: "get", expected: "GET"}, + {method: "POST", expected: "POST"}, + {method: "OPTIONS", expected: "OPTIONS"}, + {method: "connect", expected: "CONNECT"}, + {method: "trace", expected: "TRACE"}, + {method: "UNKNOWN", expected: "OTHER"}, + {method: strings.Repeat("ohno", 9999), expected: "OTHER"}, + } + + for _, d := range tests { + actual := SanitizeMethod(d.method) + if actual != d.expected { + t.Errorf("Not same: expected %#v, but got %#v", d.expected, actual) + } + } +} @@ -2,9 +2,8 @@ package caddy import ( "net/http" - "strconv" - "strings" + "github.com/caddyserver/caddy/v2/internal/metrics" "github.com/prometheus/client_golang/prometheus" "github.com/prometheus/client_golang/prometheus/collectors" "github.com/prometheus/client_golang/prometheus/promauto" @@ -46,8 +45,8 @@ func instrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler) d := newDelegator(w) next.ServeHTTP(d, r) counter.With(prometheus.Labels{ - "code": sanitizeCode(d.status), - "method": strings.ToUpper(r.Method), + "code": metrics.SanitizeCode(d.status), + "method": metrics.SanitizeMethod(r.Method), }).Inc() }) } @@ -67,12 +66,3 @@ func (d *delegator) WriteHeader(code int) { d.status = code d.ResponseWriter.WriteHeader(code) } - -func sanitizeCode(s int) string { - switch s { - case 0, 200: - return "200" - default: - return strconv.Itoa(s) - } -} diff --git a/modules/caddyhttp/metrics.go b/modules/caddyhttp/metrics.go index 3e5d639..458c22a 100644 --- a/modules/caddyhttp/metrics.go +++ b/modules/caddyhttp/metrics.go @@ -3,11 +3,10 @@ package caddyhttp import ( "context" "net/http" - "strconv" - "strings" "sync" "time" + "github.com/caddyserver/caddy/v2/internal/metrics" "github.com/prometheus/client_golang/prometheus" "github.com/prometheus/client_golang/prometheus/promauto" ) @@ -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 := metrics.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": ""} @@ -124,7 +123,7 @@ func (h *metricsInstrumentedHandler) ServeHTTP(w http.ResponseWriter, r *http.Re // being called when the headers are written. // Effectively the same behaviour as promhttp.InstrumentHandlerTimeToWriteHeader. writeHeaderRecorder := ShouldBufferFunc(func(status int, header http.Header) bool { - statusLabels["code"] = sanitizeCode(status) + statusLabels["code"] = metrics.SanitizeCode(status) ttfb := time.Since(start).Seconds() httpMetrics.responseDuration.With(statusLabels).Observe(ttfb) return false @@ -143,7 +142,7 @@ func (h *metricsInstrumentedHandler) ServeHTTP(w http.ResponseWriter, r *http.Re if statusLabels["code"] == "" { // we still sanitize it, even though it's likely to be 0. A 200 is // returned on fallthrough so we want to reflect that. - statusLabels["code"] = sanitizeCode(wrec.Status()) + statusLabels["code"] = metrics.SanitizeCode(wrec.Status()) } httpMetrics.requestDuration.With(statusLabels).Observe(dur) @@ -153,13 +152,6 @@ func (h *metricsInstrumentedHandler) ServeHTTP(w http.ResponseWriter, r *http.Re return nil } -func sanitizeCode(code int) string { - if code == 0 { - return "200" - } - return strconv.Itoa(code) -} - // taken from https://github.com/prometheus/client_golang/blob/6007b2b5cae01203111de55f753e76d8dac1f529/prometheus/promhttp/instrument_server.go#L298 func computeApproximateRequestSize(r *http.Request) int { s := 0 |