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
115
116
117
118
119
120
121
122
123
124
125
126
|
package xprometheus
import (
"encoding/json"
"expvar"
"fmt"
"strconv"
"github.com/bradfitz/iter"
"github.com/prometheus/client_golang/prometheus"
)
// A Prometheus collector that exposes all vars.
type expvarCollector struct {
descs map[int]*prometheus.Desc
}
func NewExpvarCollector() expvarCollector {
return expvarCollector{
descs: make(map[int]*prometheus.Desc),
}
}
const (
fqName = "go_expvar"
help = "All expvars"
)
var desc = prometheus.NewDesc(fqName, help, nil, nil)
// Describe implements Collector.
func (e expvarCollector) Describe(ch chan<- *prometheus.Desc) {
ch <- desc
}
// Collect implements Collector.
func (e expvarCollector) Collect(ch chan<- prometheus.Metric) {
expvar.Do(func(kv expvar.KeyValue) {
collector{
f: func(m prometheus.Metric) {
ch <- m
},
labelValues: []string{kv.Key},
descs: e.descs,
}.collectVar(kv.Value)
})
}
func labels(n int) (ls []string) {
for i := range iter.N(n) {
ls = append(ls, "key"+strconv.FormatInt(int64(i), 10))
}
return
}
type collector struct {
f func(prometheus.Metric)
labelValues []string
descs map[int]*prometheus.Desc
}
func (c *collector) newMetric(f float64) {
c.f(prometheus.MustNewConstMetric(
c.desc(),
prometheus.UntypedValue,
float64(f),
c.labelValues...))
}
func (c collector) desc() *prometheus.Desc {
d, ok := c.descs[len(c.labelValues)]
if !ok {
d = prometheus.NewDesc(fqName, "", labels(len(c.labelValues)), nil)
c.descs[len(c.labelValues)] = d
}
return d
}
func (c collector) metricError(err error) {
c.f(prometheus.NewInvalidMetric(c.desc(), err))
}
func (c collector) withLabelValue(lv string) collector {
c.labelValues = append(c.labelValues, lv)
return c
}
func (c collector) collectJsonValue(v interface{}) {
switch v := v.(type) {
case float64:
c.newMetric(v)
case map[string]interface{}:
for k, v := range v {
c.withLabelValue(k).collectJsonValue(v)
}
case bool:
if v {
c.newMetric(1)
} else {
c.newMetric(0)
}
case string:
c.f(prometheus.MustNewConstMetric(
prometheus.NewDesc("go_expvar", "",
append(labels(len(c.labelValues)), "value"),
nil),
prometheus.UntypedValue,
1,
append(c.labelValues, v)...,
))
case []interface{}:
for i, v := range v {
c.withLabelValue(strconv.FormatInt(int64(i), 10)).collectJsonValue(v)
}
default:
c.metricError(fmt.Errorf("unhandled json value type %T", v))
}
}
func (c collector) collectVar(v expvar.Var) {
var jv interface{}
if err := json.Unmarshal([]byte(v.String()), &jv); err != nil {
c.metricError(err)
}
c.collectJsonValue(jv)
}
|
