coredns/plugin/reload/setup.go
Miek Gieben b003d06003
For caddy v1 in our org (#4018)
* For caddy v1 in our org

This RP changes all imports for caddyserver/caddy to coredns/caddy. This
is the v1 code of caddy.

For the coredns/caddy repo the following changes have been made:

* anything not needed by us is deleted
* all `telemetry` stuff is deleted
* all its import paths are also changed to point to coredns/caddy
* the v1 branch has been moved to the master branch
* a v1.1.0 tag has been added to signal the latest release

Signed-off-by: Miek Gieben <miek@miek.nl>

* Fix imports

Signed-off-by: Miek Gieben <miek@miek.nl>

* Group coredns/caddy with out plugins

Signed-off-by: Miek Gieben <miek@miek.nl>

* remove this file

Signed-off-by: Miek Gieben <miek@miek.nl>

* Relax import ordering

github.com/coredns is now also a coredns dep, this makes
github.com/coredns/caddy fit more natural in the list.

Signed-off-by: Miek Gieben <miek@miek.nl>

* Fix final import

Signed-off-by: Miek Gieben <miek@miek.nl>
2020-09-24 18:14:41 +02:00

87 lines
2 KiB
Go

package reload
import (
"fmt"
"math/rand"
"sync"
"time"
"github.com/coredns/caddy"
"github.com/coredns/coredns/plugin"
clog "github.com/coredns/coredns/plugin/pkg/log"
)
var log = clog.NewWithPlugin("reload")
func init() { plugin.Register("reload", setup) }
// the info reload is global to all application, whatever number of reloads.
// it is used to transmit data between Setup and start of the hook called 'onInstanceStartup'
// channel for QUIT is never changed in purpose.
// WARNING: this data may be unsync after an invalid attempt of reload Corefile.
var (
r = reload{dur: defaultInterval, u: unused, quit: make(chan bool)}
once, shutOnce sync.Once
)
func setup(c *caddy.Controller) error {
c.Next() // 'reload'
args := c.RemainingArgs()
if len(args) > 2 {
return plugin.Error("reload", c.ArgErr())
}
i := defaultInterval
if len(args) > 0 {
d, err := time.ParseDuration(args[0])
if err != nil {
return plugin.Error("reload", err)
}
i = d
}
if i < minInterval {
return plugin.Error("reload", fmt.Errorf("interval value must be greater or equal to %v", minInterval))
}
j := defaultJitter
if len(args) > 1 {
d, err := time.ParseDuration(args[1])
if err != nil {
return plugin.Error("reload", err)
}
j = d
}
if j < minJitter {
return plugin.Error("reload", fmt.Errorf("jitter value must be greater or equal to %v", minJitter))
}
if j > i/2 {
j = i / 2
}
jitter := time.Duration(rand.Int63n(j.Nanoseconds()) - (j.Nanoseconds() / 2))
i = i + jitter
// prepare info for next onInstanceStartup event
r.setInterval(i)
r.setUsage(used)
once.Do(func() {
caddy.RegisterEventHook("reload", hook)
})
// re-register on finalShutDown as the instance most-likely will be changed
shutOnce.Do(func() {
c.OnFinalShutdown(func() error {
r.quit <- true
return nil
})
})
return nil
}
const (
minJitter = 1 * time.Second
minInterval = 2 * time.Second
defaultInterval = 30 * time.Second
defaultJitter = 15 * time.Second
)