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package kubernetes
import (
"context"
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/request"
"github.com/miekg/dns"
)
// ServeDNS implements the plugin.Handler interface.
func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
opt := plugin.Options{}
state := request.Request{W: w, Req: r, Context: ctx}
m := new(dns.Msg)
m.SetReply(r)
m.Authoritative, m.RecursionAvailable = 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, opt)
case dns.TypeAAAA:
records, err = plugin.AAAA(&k, zone, state, nil, opt)
case dns.TypeTXT:
records, err = plugin.TXT(&k, zone, state, opt)
case dns.TypeCNAME:
records, err = plugin.CNAME(&k, zone, state, opt)
case dns.TypePTR:
records, err = plugin.PTR(&k, zone, state, opt)
case dns.TypeMX:
records, extra, err = plugin.MX(&k, zone, state, opt)
case dns.TypeSRV:
records, extra, err = plugin.SRV(&k, zone, state, opt)
case dns.TypeSOA:
records, err = plugin.SOA(&k, zone, state, opt)
case dns.TypeNS:
if state.Name() == zone {
records, extra, err = plugin.NS(&k, zone, state, opt)
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, opt)
}
if k.IsNameError(err) {
if k.Fall.Through(state.Name()) {
return plugin.NextOrFailure(k.Name(), k.Next, ctx, w, r)
}
if !k.APIConn.HasSynced() {
// If we haven't synchronized with the kubernetes cluster, return server failure
return plugin.BackendError(&k, zone, dns.RcodeServerFailure, state, nil /* err */, opt)
}
return plugin.BackendError(&k, zone, dns.RcodeNameError, state, nil /* err */, opt)
}
if err != nil {
return dns.RcodeServerFailure, err
}
if len(records) == 0 {
return plugin.BackendError(&k, zone, dns.RcodeSuccess, state, nil, opt)
}
m.Answer = append(m.Answer, records...)
m.Extra = append(m.Extra, extra...)
w.WriteMsg(m)
return dns.RcodeSuccess, nil
}
// Name implements the Handler interface.
func (k Kubernetes) Name() string { return "kubernetes" }
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