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Add A lookup for headless services (#451)

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This commit is contained in:
Chris O'Haver 2016-12-02 17:50:01 -05:00 • committed by Miek Gieben
parent 8faa8354b4
commit 56d3b47d11
4 changed files with 136 additions and 6 deletions
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34
.travis/kubernetes/dns-test.yaml
View file

@ -91,6 +91,26 @@ spec:
name: c-port
protocol: UDP
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: de-d1
namespace: test-1
spec:
replicas: 2
template:
metadata:
labels:
app: app-d
spec:
containers:
- name: app-d-c
image: gcr.io/google_containers/pause-amd64:3.0
ports:
- containerPort: 1234
name: c-port
protocol: UDP
---
apiVersion: v1
kind: Service
metadata:
@ -149,3 +169,17 @@ spec:
- name: c-port
port: 1234
protocol: UDP
---
apiVersion: v1
kind: Service
metadata:
name: headless-svc
namespace: test-1
spec:
selector:
app: app-d
clusterIP: None
ports:
- name: c-port
port: 1234
protocol: UDP

51
middleware/kubernetes/controller.go
View file

@ -39,9 +39,11 @@ type dnsController struct {
svcController *cache.Controller
nsController *cache.Controller
epController *cache.Controller
svcLister cache.StoreToServiceLister
nsLister storeToNamespaceLister
epLister cache.StoreToEndpointsLister
// stopLock is used to enforce only a single call to Stop is active.
// Needed because we allow stopping through an http endpoint and
@ -76,6 +78,13 @@ func newdnsController(kubeClient *kubernetes.Clientset, resyncPeriod time.Durati
},
&api.Namespace{}, resyncPeriod, cache.ResourceEventHandlerFuncs{})
dns.epLister.Store, dns.epController = cache.NewInformer(
&cache.ListWatch{
ListFunc: endpointsListFunc(dns.client, namespace, dns.selector),
WatchFunc: endpointsWatchFunc(dns.client, namespace, dns.selector),
},
&api.Endpoints{}, resyncPeriod, cache.ResourceEventHandlerFuncs{})
return &dns
}
@ -85,6 +94,7 @@ func serviceListFunc(c *kubernetes.Clientset, ns string, s *labels.Selector) fun
opts.LabelSelector = *s
}
listV1, err := c.Core().Services(ns).List(opts)
if err != nil {
return nil, err
}
@ -119,6 +129,14 @@ func v1ToAPIFilter(in watch.Event) (out watch.Event, keep bool) {
return in, true
}
return watch.Event{Type: in.Type, Object: &apiObj}, true
case *v1.Endpoints:
var apiObj api.Endpoints
err := v1.Convert_v1_Endpoints_To_api_Endpoints(v1Obj, &apiObj, nil)
if err != nil {
log.Printf("[ERROR] Could not convert v1.Endpoint: %s", err)
return in, true
}
return watch.Event{Type: in.Type, Object: &apiObj}, true
}
log.Printf("[WARN] Unhandled v1 type in event: %v", in)
@ -169,6 +187,38 @@ func namespaceWatchFunc(c *kubernetes.Clientset, s *labels.Selector) func(option
}
}
func endpointsListFunc(c *kubernetes.Clientset, ns string, s *labels.Selector) func(api.ListOptions) (runtime.Object, error) {
return func(opts api.ListOptions) (runtime.Object, error) {
if s != nil {
opts.LabelSelector = *s
}
listV1, err := c.Core().Endpoints(ns).List(opts)
if err != nil {
return nil, err
}
var listAPI api.EndpointsList
err = v1.Convert_v1_EndpointsList_To_api_EndpointsList(listV1, &listAPI, nil)
if err != nil {
return nil, err
}
return &listAPI, err
}
}
func endpointsWatchFunc(c *kubernetes.Clientset, ns string, s *labels.Selector) func(options api.ListOptions) (watch.Interface, error) {
return func(options api.ListOptions) (watch.Interface, error) {
if s != nil {
options.LabelSelector = *s
}
w, err := c.Core().Endpoints(ns).Watch(options)
if err != nil {
return nil, err
}
return watch.Filter(w, v1ToAPIFilter), nil
}
}
func (dns *dnsController) controllersInSync() bool {
return dns.svcController.HasSynced()
}
@ -193,6 +243,7 @@ func (dns *dnsController) Stop() error {
func (dns *dnsController) Run() {
go dns.svcController.Run(dns.stopCh)
go dns.nsController.Run(dns.stopCh)
go dns.epController.Run(dns.stopCh)
<-dns.stopCh
}

34
middleware/kubernetes/kubernetes.go
View file

@ -55,7 +55,7 @@ func (k *Kubernetes) Services(state request.Request, exact bool, opt middleware.
}
// PrimaryZone will return the first non-reverse zone being handled by this middleware
func (k *Kubernetes) PrimaryZone() (string) {
func (k *Kubernetes) PrimaryZone() string {
return k.Zones[k.primaryZone]
}
@ -228,17 +228,40 @@ func (k *Kubernetes) getRecordsForServiceItems(serviceItems []*api.Service, zone
var records []msg.Service
for _, item := range serviceItems {
clusterIP := item.Spec.ClusterIP
// Create records for each exposed port...
key := k.NameTemplate.RecordNameFromNameValues(nametemplate.NameValues{TypeName: "svc", ServiceName: item.ObjectMeta.Name, Namespace: item.ObjectMeta.Namespace, Zone: zone})
key = strings.Replace(key, ".", "/", -1)
for i, p := range item.Spec.Ports {
s := msg.Service{Key: msg.Path(strconv.Itoa(i)+"."+key, "coredns"), Host: clusterIP, Port: int(p.Port)}
clusterIP := item.Spec.ClusterIP
if clusterIP == api.ClusterIPNone {
// This is a headless service, create records for each pod
epList, _ := k.APIConn.epLister.List()
for _, ep := range epList.Items {
if ep.ObjectMeta.Name == item.ObjectMeta.Name && ep.ObjectMeta.Namespace == item.ObjectMeta.Namespace {
for _, eps := range ep.Subsets {
for i, port := range eps.Ports {
for j, addr := range eps.Addresses {
refid := strconv.Itoa(j*1024 + i)
s := msg.Service{
Key: msg.Path(strings.ToLower(refid+"._"+port.Name+"._"+string(port.Protocol)+"."+key), "coredns"),
Host: addr.IP, Port: int(port.Port),
}
records = append(records, s)
}
}
}
}
}
} else {
// Create records for each exposed port...
for _, p := range item.Spec.Ports {
s := msg.Service{Key: msg.Path(strings.ToLower("_"+p.Name+"._"+string(p.Protocol)+"."+key), "coredns"), Host: clusterIP, Port: int(p.Port)}
records = append(records, s)
}
}
}
return records
}
@ -265,6 +288,7 @@ func (k *Kubernetes) getServices(namespace string, nsWildcard bool, servicename
if nsWildcard && (len(k.Namespaces) > 0) && (!dnsstrings.StringInSlice(item.Namespace, k.Namespaces)) {
continue
}
resultItems = append(resultItems, item)
}
}

21
test/kubernetes_test.go
View file

@ -59,6 +59,8 @@ var dnsTestCases = []test.Case{
test.A("svc-1-a.test-1.svc.cluster.local. 303 IN A 10.0.0.100"),
test.A("svc-1-b.test-1.svc.cluster.local. 303 IN A 10.0.0.110"),
test.A("svc-c.test-1.svc.cluster.local. 303 IN A 10.0.0.115"),
test.A("headless-svc.test-1.svc.cluster.local. 303 IN A 172.17.0.5"),
test.A("headless-svc.test-1.svc.cluster.local. 303 IN A 172.17.0.6"),
},
},
{
@ -68,6 +70,8 @@ var dnsTestCases = []test.Case{
test.A("svc-1-a.test-1.svc.cluster.local. 303 IN A 10.0.0.100"),
test.A("svc-1-b.test-1.svc.cluster.local. 303 IN A 10.0.0.110"),
test.A("svc-c.test-1.svc.cluster.local. 303 IN A 10.0.0.115"),
test.A("headless-svc.test-1.svc.cluster.local. 303 IN A 172.17.0.5"),
test.A("headless-svc.test-1.svc.cluster.local. 303 IN A 172.17.0.6"),
},
},
{
@ -87,6 +91,16 @@ var dnsTestCases = []test.Case{
test.A("svc-1-a.test-1.svc.cluster.local. 303 IN A 10.0.0.100"),
test.A("svc-1-b.test-1.svc.cluster.local. 303 IN A 10.0.0.110"),
test.A("svc-c.test-1.svc.cluster.local. 303 IN A 10.0.0.115"),
test.A("headless-svc.test-1.svc.cluster.local. 303 IN A 172.17.0.5"),
test.A("headless-svc.test-1.svc.cluster.local. 303 IN A 172.17.0.6"),
},
},
{
Qname: "headless-svc.test-1.svc.cluster.local.", Qtype: dns.TypeA,
Rcode: dns.RcodeSuccess,
Answer: []dns.RR{
test.A("headless-svc.test-1.svc.cluster.local. 303 IN A 172.17.0.5"),
test.A("headless-svc.test-1.svc.cluster.local. 303 IN A 172.17.0.6"),
},
},
//TODO: Fix below to all use test.SRV not test.A!
@ -137,6 +151,8 @@ var dnsTestCases = []test.Case{
test.SRV("_https._tcp.svc-1-a.test-1.svc.cluster.local. 303 IN SRV 10 100 443 svc-1-a.test-1.svc.cluster.local."),
test.SRV("_http._tcp.svc-1-b.test-1.svc.cluster.local. 303 IN SRV 10 100 80 svc-1-b.test-1.svc.cluster.local."),
test.SRV("_c-port._udp.svc-c.test-1.svc.cluster.local. 303 IN SRV 10 100 1234 svc-c.test-1.svc.cluster.local."),
test.SRV("_c-port._udp.headless-svc.test-1.svc.cluster.local. 303 IN SRV 10 100 1234 headless-svc.test-1.svc.cluster.local."),
test.SRV("_c-port._udp.headless-svc.test-1.svc.cluster.local. 303 IN SRV 10 100 1234 headless-svc.test-1.svc.cluster.local."),
},
},
{
@ -147,6 +163,8 @@ var dnsTestCases = []test.Case{
test.SRV("_https._tcp.svc-1-a.test-1.svc.cluster.local. 303 IN SRV 10 100 443 svc-1-a.test-1.svc.cluster.local."),
test.SRV("_http._tcp.svc-1-b.test-1.svc.cluster.local. 303 IN SRV 10 100 80 svc-1-b.test-1.svc.cluster.local."),
test.SRV("_c-port._udp.svc-c.test-1.svc.cluster.local. 303 IN SRV 10 100 1234 svc-c.test-1.svc.cluster.local."),
test.SRV("_c-port._udp.headless-svc.test-1.svc.cluster.local. 303 IN SRV 10 100 1234 headless-svc.test-1.svc.cluster.local."),
test.SRV("_c-port._udp.headless-svc.test-1.svc.cluster.local. 303 IN SRV 10 100 1234 headless-svc.test-1.svc.cluster.local."),
},
},
{
@ -167,6 +185,8 @@ var dnsTestCases = []test.Case{
test.SRV("_https._tcp.svc-1-a.test-1.svc.cluster.local. 303 IN SRV 10 100 443 svc-1-a.test-1.svc.cluster.local."),
test.SRV("_http._tcp.svc-1-b.test-1.svc.cluster.local. 303 IN SRV 10 100 80 svc-1-b.test-1.svc.cluster.local."),
test.SRV("_c-port._udp.svc-c.test-1.svc.cluster.local. 303 IN SRV 10 100 1234 svc-c.test-1.svc.cluster.local."),
test.SRV("_c-port._udp.headless-svc.test-1.svc.cluster.local. 303 IN SRV 10 100 1234 headless-svc.test-1.svc.cluster.local."),
test.SRV("_c-port._udp.headless-svc.test-1.svc.cluster.local. 303 IN SRV 10 100 1234 headless-svc.test-1.svc.cluster.local."),
},
},
{
@ -223,6 +243,7 @@ func TestKubernetesIntegration(t *testing.T) {
time.Sleep(5 * time.Second)
for _, tc := range dnsTestCases {
dnsClient := new(dns.Client)
dnsMessage := new(dns.Msg)