coredns/plugin/kubernetes/handler.go
Brad Beam 6fd954f19c support for zone transfer for kubernetes (#1259)
* plugin/kubernetes: axfr

Hook up dynamic SOA serial by setting ResourceEventHandlerFuncs in
dnsController.

Add prototype of returns msg.Services via the Transfer function. Leave
expanding this to RRs out of scope for a bit.

* plugin/kubernetes: axfr

Respond to AXFR queries

* Fixing race condition

* Fixing instantiation of dnstest writer

* Updates from review
2018-02-08 16:11:04 +00:00

89 lines
2.4 KiB
Go

package kubernetes
import (
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/pkg/dnsutil"
"github.com/coredns/coredns/request"
"github.com/miekg/dns"
"golang.org/x/net/context"
)
// ServeDNS implements the plugin.Handler interface.
func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
state := request.Request{W: w, Req: r}
m := new(dns.Msg)
m.SetReply(r)
m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
zone := plugin.Zones(k.Zones).Matches(state.Name())
if zone == "" {
return plugin.NextOrFailure(k.Name(), k.Next, ctx, w, r)
}
state.Zone = zone
var (
records []dns.RR
extra []dns.RR
err error
)
switch state.QType() {
case dns.TypeA:
records, err = plugin.A(&k, zone, state, nil, plugin.Options{})
case dns.TypeAAAA:
records, err = plugin.AAAA(&k, zone, state, nil, plugin.Options{})
case dns.TypeTXT:
records, err = plugin.TXT(&k, zone, state, plugin.Options{})
case dns.TypeCNAME:
records, err = plugin.CNAME(&k, zone, state, plugin.Options{})
case dns.TypePTR:
records, err = plugin.PTR(&k, zone, state, plugin.Options{})
case dns.TypeMX:
records, extra, err = plugin.MX(&k, zone, state, plugin.Options{})
case dns.TypeSRV:
records, extra, err = plugin.SRV(&k, zone, state, plugin.Options{})
case dns.TypeSOA:
records, err = plugin.SOA(&k, zone, state, plugin.Options{})
case dns.TypeNS:
if state.Name() == zone {
records, extra, err = plugin.NS(&k, zone, state, plugin.Options{})
break
}
fallthrough
case dns.TypeAXFR, dns.TypeIXFR:
k.Transfer(ctx, state)
default:
// Do a fake A lookup, so we can distinguish between NODATA and NXDOMAIN
_, err = plugin.A(&k, zone, state, nil, plugin.Options{})
}
if k.IsNameError(err) {
if k.Fall.Through(state.Name()) {
return plugin.NextOrFailure(k.Name(), k.Next, ctx, w, r)
}
return plugin.BackendError(&k, zone, dns.RcodeNameError, state, nil /* err */, plugin.Options{})
}
if err != nil {
return dns.RcodeServerFailure, err
}
if len(records) == 0 {
return plugin.BackendError(&k, zone, dns.RcodeSuccess, state, nil, plugin.Options{})
}
m.Answer = append(m.Answer, records...)
m.Extra = append(m.Extra, extra...)
m = dnsutil.Dedup(m)
state.SizeAndDo(m)
m, _ = state.Scrub(m)
w.WriteMsg(m)
return dns.RcodeSuccess, nil
}
// Name implements the Handler interface.
func (k Kubernetes) Name() string { return "kubernetes" }