coredns/plugin/secondary/setup.go
Miek Gieben 3a0c7c6153 plugin/file: load secondary zones lazily on startup (#2944)
This fixes a long standing bug:
fixes: #1609

Load secondary zones in a go-routine; this required another mutex to
protect some fields; I think those were needded anyway because a
transfer can also happen when we're running; we just didn't have a test
for that situation.

The test had to be changed to wait for the transfer to happen at this is
async now.

Signed-off-by: Miek Gieben <miek@miek.nl>
2019-06-30 05:22:34 +08:00

99 lines
2.2 KiB
Go

package secondary
import (
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/file"
"github.com/coredns/coredns/plugin/pkg/parse"
"github.com/coredns/coredns/plugin/pkg/upstream"
"github.com/mholt/caddy"
)
func init() {
caddy.RegisterPlugin("secondary", caddy.Plugin{
ServerType: "dns",
Action: 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 _, n := range zones.Names {
z := zones.Z[n]
if len(z.TransferFrom) > 0 {
c.OnStartup(func() error {
z.StartupOnce.Do(func() {
go func() {
z.TransferIn()
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{}
upstr := upstream.New()
for c.Next() {
if c.Val() == "secondary" {
// secondary [origin]
origins := make([]string, len(c.ServerBlockKeys))
copy(origins, c.ServerBlockKeys)
args := c.RemainingArgs()
if len(args) > 0 {
origins = args
}
for i := range origins {
origins[i] = plugin.Host(origins[i]).Normalize()
z[origins[i]] = file.NewZone(origins[i], "stdin")
names = append(names, origins[i])
}
for c.NextBlock() {
t, f := []string{}, []string{}
var e error
switch c.Val() {
case "transfer":
t, f, e = parse.Transfer(c, true)
if e != nil {
return file.Zones{}, e
}
case "upstream":
c.RemainingArgs() // eat args
default:
return file.Zones{}, c.Errf("unknown property '%s'", c.Val())
}
for _, origin := range origins {
if t != nil {
z[origin].TransferTo = append(z[origin].TransferTo, t...)
}
if f != nil {
z[origin].TransferFrom = append(z[origin].TransferFrom, f...)
}
z[origin].Upstream = upstr
}
}
}
}
return file.Zones{Z: z, Names: names}, nil
}