mirror of
				https://github.com/coredns/coredns.git
				synced 2025-11-03 18:53:13 -05:00 
			
		
		
		
	In both etcd and k8s don't error log NXDOMAIN as this log spams the logs for no good reason. Fixes #568 Better long term solution is log rate limiting for both *log* and *error*.
		
			
				
	
	
		
			97 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			97 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
package kubernetes
 | 
						|
 | 
						|
import (
 | 
						|
	"errors"
 | 
						|
 | 
						|
	"github.com/coredns/coredns/middleware"
 | 
						|
	"github.com/coredns/coredns/middleware/pkg/dnsutil"
 | 
						|
	"github.com/coredns/coredns/request"
 | 
						|
 | 
						|
	"github.com/miekg/dns"
 | 
						|
	"golang.org/x/net/context"
 | 
						|
)
 | 
						|
 | 
						|
// ServeDNS implements the middleware.Handler interface.
 | 
						|
func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 | 
						|
	state := request.Request{W: w, Req: r}
 | 
						|
	if state.QClass() != dns.ClassINET {
 | 
						|
		return dns.RcodeServerFailure, middleware.Error(k.Name(), errors.New("can only deal with ClassINET"))
 | 
						|
	}
 | 
						|
 | 
						|
	m := new(dns.Msg)
 | 
						|
	m.SetReply(r)
 | 
						|
	m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
 | 
						|
 | 
						|
	// Check that query matches one of the zones served by this middleware,
 | 
						|
	// otherwise delegate to the next in the pipeline.
 | 
						|
	zone := middleware.Zones(k.Zones).Matches(state.Name())
 | 
						|
	if zone == "" {
 | 
						|
		if state.Type() != "PTR" {
 | 
						|
			return middleware.NextOrFailure(k.Name(), k.Next, ctx, w, r)
 | 
						|
		}
 | 
						|
		// If this is a PTR request, and the request is in a defined
 | 
						|
		// pod/service cidr range, process the request in this middleware,
 | 
						|
		// otherwise pass to next middleware.
 | 
						|
		if !k.isRequestInReverseRange(state) {
 | 
						|
			return middleware.NextOrFailure(k.Name(), k.Next, ctx, w, r)
 | 
						|
		}
 | 
						|
		// Set the zone to this specific request.
 | 
						|
		zone = state.Name()
 | 
						|
	}
 | 
						|
 | 
						|
	var (
 | 
						|
		records, extra []dns.RR
 | 
						|
		err            error
 | 
						|
	)
 | 
						|
	switch state.Type() {
 | 
						|
	case "A":
 | 
						|
		records, _, err = middleware.A(&k, zone, state, nil, middleware.Options{})
 | 
						|
	case "AAAA":
 | 
						|
		records, _, err = middleware.AAAA(&k, zone, state, nil, middleware.Options{})
 | 
						|
	case "TXT":
 | 
						|
		records, _, err = middleware.TXT(&k, zone, state, middleware.Options{})
 | 
						|
	case "CNAME":
 | 
						|
		records, _, err = middleware.CNAME(&k, zone, state, middleware.Options{})
 | 
						|
	case "PTR":
 | 
						|
		records, _, err = middleware.PTR(&k, zone, state, middleware.Options{})
 | 
						|
	case "MX":
 | 
						|
		records, extra, _, err = middleware.MX(&k, zone, state, middleware.Options{})
 | 
						|
	case "SRV":
 | 
						|
		records, extra, _, err = middleware.SRV(&k, zone, state, middleware.Options{})
 | 
						|
	case "SOA":
 | 
						|
		records, _, err = middleware.SOA(&k, zone, state, middleware.Options{})
 | 
						|
	case "NS":
 | 
						|
		if state.Name() == zone {
 | 
						|
			records, extra, _, err = middleware.NS(&k, zone, state, middleware.Options{})
 | 
						|
			break
 | 
						|
		}
 | 
						|
		fallthrough
 | 
						|
	default:
 | 
						|
		// Do a fake A lookup, so we can distinguish between NODATA and NXDOMAIN
 | 
						|
		_, _, err = middleware.A(&k, zone, state, nil, middleware.Options{})
 | 
						|
	}
 | 
						|
	if k.IsNameError(err) {
 | 
						|
		// Make err nil when returning here, so we don't log spam for NXDOMAIN.
 | 
						|
		return middleware.BackendError(&k, zone, dns.RcodeNameError, state, nil /*debug*/, nil /* err */, middleware.Options{})
 | 
						|
	}
 | 
						|
	if err != nil {
 | 
						|
		return dns.RcodeServerFailure, err
 | 
						|
	}
 | 
						|
 | 
						|
	if len(records) == 0 {
 | 
						|
		return middleware.BackendError(&k, zone, dns.RcodeSuccess, state, nil /*debug*/, nil, middleware.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" }
 |