Browse Source

metrics: Always track method label in uppercase (#3742)

* metrics: Always track method label in uppercase

Signed-off-by: Dave Henderson <dhenderson@gmail.com>

* Just use strings.ToUpper for clarity

Signed-off-by: Dave Henderson <dhenderson@gmail.com>
master2 v2.2.0
Dave Henderson 1 year ago
committed by GitHub
parent
commit
f197cec7f3
No known key found for this signature in database GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 52 additions and 5 deletions
  1. +2
    -3
      admin.go
  2. +45
    -0
      metrics.go
  3. +5
    -2
      modules/caddyhttp/metrics.go

+ 2
- 3
admin.go View File

@ -36,7 +36,6 @@ import (
"time"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
"go.uber.org/zap"
)
@ -111,7 +110,7 @@ func (admin AdminConfig) newAdminHandler(addr NetworkAddress) adminHandler {
addRouteWithMetrics := func(pattern string, handlerLabel string, h http.Handler) {
labels := prometheus.Labels{"path": pattern, "handler": handlerLabel}
h = promhttp.InstrumentHandlerCounter(
h = instrumentHandlerCounter(
adminMetrics.requestCount.MustCurryWith(labels),
h,
)
@ -126,7 +125,7 @@ func (admin AdminConfig) newAdminHandler(addr NetworkAddress) adminHandler {
labels := prometheus.Labels{
"path": pattern,
"handler": handlerLabel,
"method": r.Method,
"method": strings.ToUpper(r.Method),
}
adminMetrics.requestErrors.With(labels).Inc()
}


+ 45
- 0
metrics.go View File

@ -1,6 +1,10 @@
package caddy
import (
"net/http"
"strconv"
"strings"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
)
@ -30,3 +34,44 @@ var adminMetrics = struct {
requestCount *prometheus.CounterVec
requestErrors *prometheus.CounterVec
}{}
// Similar to promhttp.InstrumentHandlerCounter, but upper-cases method names
// instead of lower-casing them.
//
// Unlike promhttp.InstrumentHandlerCounter, this assumes a "code" and "method"
// label is present, and will panic otherwise.
func instrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler) http.HandlerFunc {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
d := newDelegator(w)
next.ServeHTTP(d, r)
counter.With(prometheus.Labels{
"code": sanitizeCode(d.status),
"method": strings.ToUpper(r.Method),
}).Inc()
})
}
func newDelegator(w http.ResponseWriter) *delegator {
return &delegator{
ResponseWriter: w,
}
}
type delegator struct {
http.ResponseWriter
status int
}
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)
}
}

+ 5
- 2
modules/caddyhttp/metrics.go View File

@ -4,6 +4,7 @@ import (
"context"
"net/http"
"strconv"
"strings"
"sync"
"time"
@ -108,7 +109,10 @@ 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}
statusLabels := prometheus.Labels{"server": server, "handler": h.handler, "method": r.Method, "code": ""}
method := strings.ToUpper(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": ""}
inFlight := httpMetrics.requestInFlight.With(labels)
inFlight.Inc()
@ -154,7 +158,6 @@ func sanitizeCode(code int) string {
return "200"
}
return strconv.Itoa(code)
}
// taken from https://github.com/prometheus/client_golang/blob/6007b2b5cae01203111de55f753e76d8dac1f529/prometheus/promhttp/instrument_server.go#L298


Loading…
Cancel
Save