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
|
package health
import (
"net"
"time"
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/metrics"
"github.com/mholt/caddy"
)
func init() {
caddy.RegisterPlugin("health", caddy.Plugin{
ServerType: "dns",
Action: setup,
})
}
func setup(c *caddy.Controller) error {
addr, err := healthParse(c)
if err != nil {
return plugin.Error("health", err)
}
h := &health{Addr: addr, stop: make(chan bool)}
c.OnStartup(func() error {
plugins := dnsserver.GetConfig(c).Handlers()
for _, p := range plugins {
if x, ok := p.(Healther); ok {
h.h = append(h.h, x)
}
}
return nil
})
c.OnStartup(func() error {
// Poll all middleware every second.
h.poll()
go func() {
for {
<-time.After(1 * time.Second)
h.poll()
}
}()
return nil
})
c.OnStartup(func() error {
onceMetric.Do(func() {
m := dnsserver.GetConfig(c).Handler("prometheus")
if m == nil {
return
}
if x, ok := m.(*metrics.Metrics); ok {
x.MustRegister(HealthDuration)
}
})
return nil
})
c.OnStartup(h.OnStartup)
c.OnFinalShutdown(h.OnShutdown)
// Don't do AddPlugin, as health is not *really* a plugin just a separate webserver running.
return nil
}
func healthParse(c *caddy.Controller) (string, error) {
addr := ""
for c.Next() {
args := c.RemainingArgs()
switch len(args) {
case 0:
case 1:
addr = args[0]
if _, _, e := net.SplitHostPort(addr); e != nil {
return "", e
}
default:
return "", c.ArgErr()
}
}
return addr, nil
}
|
