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|
package health
import (
"fmt"
"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, lame, err := healthParse(c)
if err != nil {
return plugin.Error("health", err)
}
h := newHealth(addr)
h.lameduck = lame
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 {
select {
case <-time.After(1 * time.Second):
h.poll()
case <-h.pollstop:
return
}
}
}()
return nil
})
c.OnStartup(func() error {
once.Do(func() { metrics.MustRegister(c, HealthDuration) })
return nil
})
c.OnStartup(h.OnStartup)
c.OnRestart(h.OnRestart)
c.OnFinalShutdown(h.OnFinalShutdown)
// Don't do AddPlugin, as health is not *really* a plugin just a separate webserver running.
return nil
}
func healthParse(c *caddy.Controller) (string, time.Duration, error) {
addr := ""
dur := time.Duration(0)
for c.Next() {
args := c.RemainingArgs()
switch len(args) {
case 0:
case 1:
addr = args[0]
if _, _, e := net.SplitHostPort(addr); e != nil {
return "", 0, e
}
default:
return "", 0, c.ArgErr()
}
for c.NextBlock() {
switch c.Val() {
case "lameduck":
args := c.RemainingArgs()
if len(args) != 1 {
return "", 0, c.ArgErr()
}
l, err := time.ParseDuration(args[0])
if err != nil {
return "", 0, fmt.Errorf("unable to parse lameduck duration value: '%v' : %v", args[0], err)
}
dur = l
default:
return "", 0, c.ArgErr()
}
}
}
return addr, dur, nil
}
|
