-
Notifications
You must be signed in to change notification settings - Fork 31
/
middleware.go
114 lines (101 loc) · 3.84 KB
/
middleware.go
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
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
// Port https://github.com/zbindenren/negroni-prometheus for chi router
package chiprometheus
import (
"net/http"
"strings"
"time"
"github.com/go-chi/chi"
"github.com/go-chi/chi/middleware"
"github.com/prometheus/client_golang/prometheus"
)
var (
dflBuckets = []float64{300, 1200, 5000}
)
const (
reqsName = "chi_requests_total"
latencyName = "chi_request_duration_milliseconds"
patternReqsName = "chi_pattern_requests_total"
patternLatencyName = "chi_pattern_request_duration_milliseconds"
)
// Middleware is a handler that exposes prometheus metrics for the number of requests,
// the latency and the response size, partitioned by status code, method and HTTP path.
type Middleware struct {
reqs *prometheus.CounterVec
latency *prometheus.HistogramVec
}
// NewMiddleware returns a new prometheus Middleware handler.
func NewMiddleware(name string, buckets ...float64) func(next http.Handler) http.Handler {
var m Middleware
m.reqs = prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: reqsName,
Help: "How many HTTP requests processed, partitioned by status code, method and HTTP path.",
ConstLabels: prometheus.Labels{"service": name},
},
[]string{"code", "method", "path"},
)
prometheus.MustRegister(m.reqs)
if len(buckets) == 0 {
buckets = dflBuckets
}
m.latency = prometheus.NewHistogramVec(prometheus.HistogramOpts{
Name: latencyName,
Help: "How long it took to process the request, partitioned by status code, method and HTTP path.",
ConstLabels: prometheus.Labels{"service": name},
Buckets: buckets,
},
[]string{"code", "method", "path"},
)
prometheus.MustRegister(m.latency)
return m.handler
}
func (c Middleware) handler(next http.Handler) http.Handler {
fn := func(w http.ResponseWriter, r *http.Request) {
start := time.Now()
ww := middleware.NewWrapResponseWriter(w, r.ProtoMajor)
next.ServeHTTP(ww, r)
c.reqs.WithLabelValues(http.StatusText(ww.Status()), r.Method, r.URL.Path).Inc()
c.latency.WithLabelValues(http.StatusText(ww.Status()), r.Method, r.URL.Path).Observe(float64(time.Since(start).Nanoseconds()) / 1000000)
}
return http.HandlerFunc(fn)
}
// NewPatternMiddleware returns a new prometheus Middleware handler that groups requests by the chi routing pattern.
// EX: /users/{firstName} instead of /users/bob
func NewPatternMiddleware(name string, buckets ...float64) func(next http.Handler) http.Handler {
var m Middleware
m.reqs = prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: patternReqsName,
Help: "How many HTTP requests processed, partitioned by status code, method and HTTP path (with patterns).",
ConstLabels: prometheus.Labels{"service": name},
},
[]string{"code", "method", "path"},
)
prometheus.MustRegister(m.reqs)
if len(buckets) == 0 {
buckets = dflBuckets
}
m.latency = prometheus.NewHistogramVec(prometheus.HistogramOpts{
Name: patternLatencyName,
Help: "How long it took to process the request, partitioned by status code, method and HTTP path (with patterns).",
ConstLabels: prometheus.Labels{"service": name},
Buckets: buckets,
},
[]string{"code", "method", "path"},
)
prometheus.MustRegister(m.latency)
return m.patternHandler
}
func (c Middleware) patternHandler(next http.Handler) http.Handler {
fn := func(w http.ResponseWriter, r *http.Request) {
start := time.Now()
ww := middleware.NewWrapResponseWriter(w, r.ProtoMajor)
next.ServeHTTP(ww, r)
rctx := chi.RouteContext(r.Context())
routePattern := strings.Join(rctx.RoutePatterns, "")
routePattern = strings.Replace(routePattern, "/*/", "/", -1)
c.reqs.WithLabelValues(http.StatusText(ww.Status()), r.Method, routePattern).Inc()
c.latency.WithLabelValues(http.StatusText(ww.Status()), r.Method, routePattern).Observe(float64(time.Since(start).Nanoseconds()) / 1000000)
}
return http.HandlerFunc(fn)
}