coredns/plugin/secondary/setup.go
2022-07-10 11:06:33 -07:00

99 lines
2.3 KiB
Go

package secondary
import (
"time"
"github.com/coredns/caddy"
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/file"
clog "github.com/coredns/coredns/plugin/pkg/log"
"github.com/coredns/coredns/plugin/pkg/parse"
"github.com/coredns/coredns/plugin/pkg/upstream"
)
var log = clog.NewWithPlugin("secondary")
func init() { plugin.Register("secondary", setup) }
func setup(c *caddy.Controller) error {
zones, err := secondaryParse(c)
if err != nil {
return plugin.Error("secondary", err)
}
// Add startup functions to retrieve the zone and keep it up to date.
for i := range zones.Names {
n := zones.Names[i]
z := zones.Z[n]
if len(z.TransferFrom) > 0 {
c.OnStartup(func() error {
z.StartupOnce.Do(func() {
go func() {
dur := time.Millisecond * 250
step := time.Duration(2)
max := time.Second * 10
for {
err := z.TransferIn()
if err == nil {
break
}
log.Warningf("All '%s' masters failed to transfer, retrying in %s: %s", n, dur.String(), err)
time.Sleep(dur)
dur = step * dur
if dur > max {
dur = max
}
}
z.Update()
}()
})
return nil
})
}
}
dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
return Secondary{file.File{Next: next, Zones: zones}}
})
return nil
}
func secondaryParse(c *caddy.Controller) (file.Zones, error) {
z := make(map[string]*file.Zone)
names := []string{}
for c.Next() {
if c.Val() == "secondary" {
// secondary [origin]
origins := plugin.OriginsFromArgsOrServerBlock(c.RemainingArgs(), c.ServerBlockKeys)
for i := range origins {
z[origins[i]] = file.NewZone(origins[i], "stdin")
names = append(names, origins[i])
}
for c.NextBlock() {
var f []string
switch c.Val() {
case "transfer":
var err error
f, err = parse.TransferIn(c)
if err != nil {
return file.Zones{}, err
}
default:
return file.Zones{}, c.Errf("unknown property '%s'", c.Val())
}
for _, origin := range origins {
if f != nil {
z[origin].TransferFrom = append(z[origin].TransferFrom, f...)
}
z[origin].Upstream = upstream.New()
}
}
}
}
return file.Zones{Z: z, Names: names}, nil
}