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-rw-r--r--middleware/kubernetes/handler.go39
-rw-r--r--middleware/kubernetes/kubernetes.go60
-rw-r--r--middleware/kubernetes/lookup.go271
3 files changed, 54 insertions, 316 deletions
diff --git a/middleware/kubernetes/handler.go b/middleware/kubernetes/handler.go
index 95009a04b..eb3071b18 100644
--- a/middleware/kubernetes/handler.go
+++ b/middleware/kubernetes/handler.go
@@ -23,6 +23,8 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
// TODO: find an alternative to this block
+ // TODO(miek): Why is this even here, why does the path Etcd takes not work?
+ // Should be a "case PTR" below. I would also like to use middleware.PTR for this.
ip := dnsutil.ExtractAddressFromReverse(state.Name())
if ip != "" {
records := k.getServiceRecordForIP(ip, state.Name())
@@ -54,41 +56,38 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
)
switch state.Type() {
case "A":
- records, err = k.A(zone, state, nil)
+ records, _, err = middleware.A(&k, zone, state, nil, middleware.Options{}) // Hmm wrt to '&k'
case "AAAA":
- records, err = k.AAAA(zone, state, nil)
+ records, _, err = middleware.AAAA(&k, zone, state, nil, middleware.Options{})
case "TXT":
- records, err = k.TXT(zone, state)
- // TODO: change lookup to return appropriate error. Then add code below
- // this switch to check for the error and return not implemented.
- //return dns.RcodeNotImplemented, nil
+ records, _, err = middleware.TXT(&k, zone, state, middleware.Options{})
case "CNAME":
- records, err = k.CNAME(zone, state)
+ records, _, err = middleware.CNAME(&k, zone, state, middleware.Options{})
case "MX":
- records, extra, err = k.MX(zone, state)
+ records, extra, _, err = middleware.MX(&k, zone, state, middleware.Options{})
case "SRV":
- records, extra, err = k.SRV(zone, state)
+ records, extra, _, err = middleware.SRV(&k, zone, state, middleware.Options{})
case "SOA":
- records = []dns.RR{k.SOA(zone, state)}
+ records, _, err = middleware.SOA(&k, zone, state, middleware.Options{})
case "NS":
if state.Name() == zone {
- records, extra, err = k.NS(zone, state)
+ 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 = k.A(zone, state, nil)
+ _, _, err = middleware.A(&k, zone, state, nil, middleware.Options{})
}
- if isKubernetesNameError(err) {
- return k.Err(zone, dns.RcodeNameError, state)
+ if k.IsNameError(err) {
+ return middleware.BackendError(&k, zone, dns.RcodeNameError, state, nil /*debug*/, err, middleware.Options{})
}
if err != nil {
return dns.RcodeServerFailure, err
}
if len(records) == 0 {
- return k.Err(zone, dns.RcodeSuccess, state)
+ return middleware.BackendError(&k, zone, dns.RcodeSuccess, state, nil /*debug*/, nil, middleware.Options{})
}
m.Answer = append(m.Answer, records...)
@@ -103,13 +102,3 @@ func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.M
// Name implements the Handler interface.
func (k Kubernetes) Name() string { return "kubernetes" }
-
-// Err writes an error response back to the client.
-func (k Kubernetes) Err(zone string, rcode int, state request.Request) (int, error) {
- m := new(dns.Msg)
- m.SetRcode(state.Req, rcode)
- m.Ns = []dns.RR{k.SOA(zone, state)}
- state.SizeAndDo(m)
- state.W.WriteMsg(m)
- return rcode, nil
-}
diff --git a/middleware/kubernetes/kubernetes.go b/middleware/kubernetes/kubernetes.go
index ee46f4632..43d98e079 100644
--- a/middleware/kubernetes/kubernetes.go
+++ b/middleware/kubernetes/kubernetes.go
@@ -3,6 +3,7 @@ package kubernetes
import (
"errors"
+ "fmt"
"log"
"strings"
"time"
@@ -11,8 +12,9 @@ import (
"github.com/miekg/coredns/middleware/etcd/msg"
"github.com/miekg/coredns/middleware/kubernetes/nametemplate"
"github.com/miekg/coredns/middleware/pkg/dnsutil"
- dns_strings "github.com/miekg/coredns/middleware/pkg/strings"
+ dnsstrings "github.com/miekg/coredns/middleware/pkg/strings"
"github.com/miekg/coredns/middleware/proxy"
+ "github.com/miekg/coredns/request"
"github.com/miekg/dns"
"k8s.io/kubernetes/pkg/api"
@@ -41,6 +43,28 @@ type Kubernetes struct {
Selector *labels.Selector
}
+// Services implements the ServiceBackend interface.
+func (k *Kubernetes) Services(state request.Request, exact bool, opt middleware.Options) ([]msg.Service, []msg.Service, error) {
+ s, e := k.Records(state.Name(), exact)
+ return s, nil, e // Haven't implemented debug queries yet.
+}
+
+// Lookup implements the ServiceBackend interface.
+func (k *Kubernetes) Lookup(state request.Request, name string, typ uint16) (*dns.Msg, error) {
+ return k.Proxy.Lookup(state, name, typ)
+}
+
+// IsNameError implements the ServiceBackend interface.
+// TODO(infoblox): implement!
+func (k *Kubernetes) IsNameError(err error) bool {
+ return false
+}
+
+// Debug implements the ServiceBackend interface.
+func (k *Kubernetes) Debug() string {
+ return "debug"
+}
+
func (k *Kubernetes) getClientConfig() (*restclient.Config, error) {
// For a custom api server or running outside a k8s cluster
// set URL in env.KUBERNETES_MASTER or set endpoint in Corefile
@@ -73,7 +97,6 @@ func (k *Kubernetes) getClientConfig() (*restclient.Config, error) {
}
// InitKubeCache initializes a new Kubernetes cache.
-// TODO(miek): is this correct?
func (k *Kubernetes) InitKubeCache() error {
config, err := k.getClientConfig()
@@ -83,21 +106,24 @@ func (k *Kubernetes) InitKubeCache() error {
kubeClient, err := clientset_generated.NewForConfig(config)
if err != nil {
- log.Printf("[ERROR] Failed to create kubernetes notification controller: %v", err)
- return err
+ return fmt.Errorf("Failed to create kubernetes notification controller: %v", err)
}
- if k.LabelSelector == nil {
- log.Printf("[INFO] Kubernetes middleware configured without a label selector. No label-based filtering will be performed.")
- } else {
+
+ if k.LabelSelector != nil {
var selector labels.Selector
selector, err = unversionedapi.LabelSelectorAsSelector(k.LabelSelector)
k.Selector = &selector
if err != nil {
- log.Printf("[ERROR] Unable to create Selector for LabelSelector '%s'.Error was: %s", k.LabelSelector, err)
- return err
+ return fmt.Errorf("Unable to create Selector for LabelSelector '%s'.Error was: %s", k.LabelSelector, err)
}
+ }
+
+ if k.LabelSelector == nil {
+ log.Printf("[INFO] Kubernetes middleware configured without a label selector. No label-based filtering will be performed.")
+ } else {
log.Printf("[INFO] Kubernetes middleware configured with the label selector '%s'. Only kubernetes objects matching this label selector will be exposed.", unversionedapi.FormatLabelSelector(k.LabelSelector))
}
+
k.APIConn = newdnsController(kubeClient, k.ResyncPeriod, k.Selector)
return err
@@ -125,12 +151,11 @@ func (k *Kubernetes) getZoneForName(name string) (string, []string) {
return zone, serviceSegments
}
-// Records looks up services in kubernetes.
-// If exact is true, it will lookup just
-// this name. This is used when find matches when completing SRV lookups
+// Records looks up services in kubernetes. If exact is true, it will lookup
+// just this name. This is used when find matches when completing SRV lookups
// for instance.
func (k *Kubernetes) Records(name string, exact bool) ([]msg.Service, error) {
- // TODO: refector this.
+ // TODO: refactor this.
// Right now NamespaceFromSegmentArray do not supports PRE queries
ip := dnsutil.ExtractAddressFromReverse(name)
if ip != "" {
@@ -169,7 +194,7 @@ func (k *Kubernetes) Records(name string, exact bool) ([]msg.Service, error) {
// Abort if the namespace does not contain a wildcard, and namespace is not published per CoreFile
// Case where namespace contains a wildcard is handled in Get(...) method.
- if (!nsWildcard) && (len(k.Namespaces) > 0) && (!dns_strings.StringInSlice(namespace, k.Namespaces)) {
+ if (!nsWildcard) && (len(k.Namespaces) > 0) && (!dnsstrings.StringInSlice(namespace, k.Namespaces)) {
return nil, nil
}
@@ -219,7 +244,7 @@ func (k *Kubernetes) Get(namespace string, nsWildcard bool, servicename string,
if symbolMatches(namespace, item.Namespace, nsWildcard) && symbolMatches(servicename, item.Name, serviceWildcard) {
// If namespace has a wildcard, filter results against Corefile namespace list.
// (Namespaces without a wildcard were filtered before the call to this function.)
- if nsWildcard && (len(k.Namespaces) > 0) && (!dns_strings.StringInSlice(item.Namespace, k.Namespaces)) {
+ if nsWildcard && (len(k.Namespaces) > 0) && (!dnsstrings.StringInSlice(item.Namespace, k.Namespaces)) {
continue
}
resultItems = append(resultItems, item)
@@ -242,11 +267,6 @@ func symbolMatches(queryString string, candidateString string, wildcard bool) bo
return result
}
-// kubernetesNameError checks if the error is ErrorCodeKeyNotFound from kubernetes.
-func isKubernetesNameError(err error) bool {
- return false
-}
-
func (k *Kubernetes) getServiceRecordForIP(ip, name string) []msg.Service {
svcList, err := k.APIConn.svcLister.List(labels.Everything())
if err != nil {
diff --git a/middleware/kubernetes/lookup.go b/middleware/kubernetes/lookup.go
index fa41686a6..61689baac 100644
--- a/middleware/kubernetes/lookup.go
+++ b/middleware/kubernetes/lookup.go
@@ -2,11 +2,8 @@ package kubernetes
import (
"fmt"
- "math"
"net"
- "time"
- "github.com/miekg/coredns/middleware"
"github.com/miekg/coredns/middleware/etcd/msg"
"github.com/miekg/coredns/middleware/pkg/dnsutil"
"github.com/miekg/coredns/request"
@@ -19,278 +16,10 @@ func (k Kubernetes) records(state request.Request, exact bool) ([]msg.Service, e
if err != nil {
return nil, err
}
- // TODO: Do we want to support the SkyDNS (hacky) Group feature?
services = msg.Group(services)
return services, nil
}
-// A returns A records from kubernetes or an error.
-func (k Kubernetes) A(zone string, state request.Request, previousRecords []dns.RR) (records []dns.RR, err error) {
- services, err := k.records(state, false)
- if err != nil {
- return nil, err
- }
-
- for _, serv := range services {
- ip := net.ParseIP(serv.Host)
- switch {
- case ip == nil:
- // TODO(miek): lowercasing? Should lowercase in everything see #85
- if middleware.Name(state.Name()).Matches(dns.Fqdn(serv.Host)) {
- // x CNAME x is a direct loop, don't add those
- continue
- }
-
- newRecord := serv.NewCNAME(state.QName(), serv.Host)
- if len(previousRecords) > 7 {
- // don't add it, and just continue
- continue
- }
- if dnsutil.DuplicateCNAME(newRecord, previousRecords) {
- continue
- }
-
- state1 := state.NewWithQuestion(serv.Host, state.QType())
- nextRecords, err := k.A(zone, state1, append(previousRecords, newRecord))
-
- if err == nil {
- // Not only have we found something we should add the CNAME and the IP addresses.
- if len(nextRecords) > 0 {
- records = append(records, newRecord)
- records = append(records, nextRecords...)
- }
- continue
- }
- // This means we can not complete the CNAME, try to look else where.
- target := newRecord.Target
- if dns.IsSubDomain(zone, target) {
- // We should already have found it
- continue
- }
- mes, err := k.Proxy.Lookup(state, target, state.QType())
- if err != nil {
- continue
- }
- // Len(mes.Answer) > 0 here is well?
- records = append(records, newRecord)
- records = append(records, mes.Answer...)
- continue
- case ip.To4() != nil:
- records = append(records, serv.NewA(state.QName(), ip.To4()))
- case ip.To4() == nil:
- // nodata?
- }
- }
- return records, nil
-}
-
-// AAAA returns AAAA records from kubernetes or an error.
-func (k Kubernetes) AAAA(zone string, state request.Request, previousRecords []dns.RR) (records []dns.RR, err error) {
- services, err := k.records(state, false)
- if err != nil {
- return nil, err
- }
-
- for _, serv := range services {
- ip := net.ParseIP(serv.Host)
- switch {
- case ip == nil:
- // Try to resolve as CNAME if it's not an IP, but only if we don't create loops.
- if middleware.Name(state.Name()).Matches(dns.Fqdn(serv.Host)) {
- // x CNAME x is a direct loop, don't add those
- continue
- }
-
- newRecord := serv.NewCNAME(state.QName(), serv.Host)
- if len(previousRecords) > 7 {
- // don't add it, and just continue
- continue
- }
- if dnsutil.DuplicateCNAME(newRecord, previousRecords) {
- continue
- }
-
- state1 := state.NewWithQuestion(serv.Host, state.QType())
- nextRecords, err := k.AAAA(zone, state1, append(previousRecords, newRecord))
-
- if err == nil {
- // Not only have we found something we should add the CNAME and the IP addresses.
- if len(nextRecords) > 0 {
- records = append(records, newRecord)
- records = append(records, nextRecords...)
- }
- continue
- }
- // This means we can not complete the CNAME, try to look else where.
- target := newRecord.Target
- if dns.IsSubDomain(zone, target) {
- // We should already have found it
- continue
- }
- m1, e1 := k.Proxy.Lookup(state, target, state.QType())
- if e1 != nil {
- continue
- }
- // Len(m1.Answer) > 0 here is well?
- records = append(records, newRecord)
- records = append(records, m1.Answer...)
- continue
- // both here again
- case ip.To4() != nil:
- // nada?
- case ip.To4() == nil:
- records = append(records, serv.NewAAAA(state.QName(), ip.To16()))
- }
- }
- return records, nil
-}
-
-// SRV returns SRV records from kubernetes.
-// If the Target is not a name but an IP address, a name is created on the fly and the IP address is put in
-// the additional section.
-func (k Kubernetes) SRV(zone string, state request.Request) (records []dns.RR, extra []dns.RR, err error) {
- services, err := k.records(state, false)
- if err != nil {
- return nil, nil, err
- }
-
- // Looping twice to get the right weight vs priority
- w := make(map[int]int)
- for _, serv := range services {
- weight := 100
- if serv.Weight != 0 {
- weight = serv.Weight
- }
- if _, ok := w[serv.Priority]; !ok {
- w[serv.Priority] = weight
- continue
- }
- w[serv.Priority] += weight
- }
- lookup := make(map[string]bool)
- for _, serv := range services {
- w1 := 100.0 / float64(w[serv.Priority])
- if serv.Weight == 0 {
- w1 *= 100
- } else {
- w1 *= float64(serv.Weight)
- }
- weight := uint16(math.Floor(w1))
- ip := net.ParseIP(serv.Host)
- switch {
- case ip == nil:
- srv := serv.NewSRV(state.QName(), weight)
- records = append(records, srv)
-
- if _, ok := lookup[srv.Target]; ok {
- break
- }
-
- lookup[srv.Target] = true
-
- if !dns.IsSubDomain(zone, srv.Target) {
- m1, e1 := k.Proxy.Lookup(state, srv.Target, dns.TypeA)
- if e1 == nil {
- extra = append(extra, m1.Answer...)
- }
- m1, e1 = k.Proxy.Lookup(state, srv.Target, dns.TypeAAAA)
- if e1 == nil {
- // If we have seen CNAME's we *assume* that they are already added.
- for _, a := range m1.Answer {
- if _, ok := a.(*dns.CNAME); !ok {
- extra = append(extra, a)
- }
- }
- }
- break
- }
- // Internal name, we should have some info on them, either v4 or v6
- // Clients expect a complete answer, because we are a recursor in their view.
- state1 := state.NewWithQuestion(srv.Target, dns.TypeA)
- addr, e1 := k.A(zone, state1, nil)
- if e1 == nil {
- extra = append(extra, addr...)
- }
- // k.AAA(zone, state1, nil) as well...?
- case ip.To4() != nil:
- serv.Host = serv.Key
- srv := serv.NewSRV(state.QName(), weight)
-
- records = append(records, srv)
- extra = append(extra, serv.NewA(srv.Target, ip.To4()))
- case ip.To4() == nil:
- serv.Host = serv.Key
- srv := serv.NewSRV(state.QName(), weight)
-
- records = append(records, srv)
- extra = append(extra, serv.NewAAAA(srv.Target, ip.To16()))
- }
- }
- return records, extra, nil
-}
-
-// MX returns MX records from kubernetes. Not implemented!
-func (k Kubernetes) MX(zone string, state request.Request) (records []dns.RR, extra []dns.RR, err error) {
- return nil, nil, err
-}
-
-// CNAME returns CNAME records from kubernetes. Not implemented!
-func (k Kubernetes) CNAME(zone string, state request.Request) (records []dns.RR, err error) {
- return nil, err
-}
-
-// TXT returns TXT records from kubernetes. Not implemented!
-func (k Kubernetes) TXT(zone string, state request.Request) (records []dns.RR, err error) {
- return nil, err
-}
-
-// NS returns NS records from kubernetes.
-func (k Kubernetes) NS(zone string, state request.Request) (records, extra []dns.RR, err error) {
- // NS record for this zone live in a special place, ns.dns.<zone>. Fake our lookup.
- // only a tad bit fishy...
- old := state.QName()
-
- state.Clear()
- state.Req.Question[0].Name = "ns.dns." + zone
- services, err := k.records(state, false)
- if err != nil {
- return nil, nil, err
- }
- // ... and reset
- state.Req.Question[0].Name = old
-
- for _, serv := range services {
- ip := net.ParseIP(serv.Host)
- switch {
- case ip == nil:
- return nil, nil, fmt.Errorf("NS record must be an IP address: %s", serv.Host)
- case ip.To4() != nil:
- serv.Host = serv.Key
- records = append(records, serv.NewNS(state.QName()))
- extra = append(extra, serv.NewA(serv.Host, ip.To4()))
- case ip.To4() == nil:
- serv.Host = serv.Key
- records = append(records, serv.NewNS(state.QName()))
- extra = append(extra, serv.NewAAAA(serv.Host, ip.To16()))
- }
- }
- return records, extra, nil
-}
-
-// SOA Record returns a SOA record from kubernetes.
-func (k Kubernetes) SOA(zone string, state request.Request) *dns.SOA {
- header := dns.RR_Header{Name: zone, Rrtype: dns.TypeSOA, Ttl: 300, Class: dns.ClassINET}
- return &dns.SOA{Hdr: header,
- Mbox: "hostmaster." + zone,
- Ns: "ns.dns." + zone,
- Serial: uint32(time.Now().Unix()),
- Refresh: 7200,
- Retry: 1800,
- Expire: 86400,
- Minttl: 60,
- }
-}
-
// PTR Record returns PTR records from kubernetes.
func (k Kubernetes) PTR(zone string, state request.Request) ([]dns.RR, error) {
reverseIP := dnsutil.ExtractAddressFromReverse(state.Name())
generated by cgit v1.2.3 (git 2.39.1) at 2025-08-01 11:40:55 +0000