1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
|
package caddy
import (
"net/http"
"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"
)
// define and register the metrics used in this package.
func init() {
prometheus.MustRegister(collectors.NewBuildInfoCollector())
const ns, sub = "caddy", "admin"
adminMetrics.requestCount = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: ns,
Subsystem: sub,
Name: "http_requests_total",
Help: "Counter of requests made to the Admin API's HTTP endpoints.",
}, []string{"handler", "path", "code", "method"})
adminMetrics.requestErrors = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: ns,
Subsystem: sub,
Name: "http_request_errors_total",
Help: "Number of requests resulting in middleware errors.",
}, []string{"handler", "path", "method"})
}
// adminMetrics is a collection of metrics that can be tracked for the admin API.
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": metrics.SanitizeCode(d.status),
"method": metrics.SanitizeMethod(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)
}
// Unwrap returns the underlying ResponseWriter, necessary for
// http.ResponseController to work correctly.
func (d *delegator) Unwrap() http.ResponseWriter {
return d.ResponseWriter
}
|
