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|
package kubernetes
import (
"errors"
"fmt"
"sync"
"time"
"k8s.io/client-go/kubernetes"
api "k8s.io/client-go/pkg/api/v1"
"k8s.io/client-go/tools/cache"
meta "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/watch"
)
var (
namespace = api.NamespaceAll
)
const podIPIndex = "PodIP"
type dnsController interface {
ServiceList() []*api.Service
PodIndex(string) []*api.Pod
EndpointsList() []*api.Endpoints
GetNodeByName(string) (*api.Node, error)
Run()
Stop() error
}
type dnsControl struct {
client *kubernetes.Clientset
selector *labels.Selector
svcController cache.Controller
podController cache.Controller
epController cache.Controller
svcLister cache.Indexer
podLister cache.Indexer
epLister cache.Store
// stopLock is used to enforce only a single call to Stop is active.
// Needed because we allow stopping through an http endpoint and
// allowing concurrent stoppers leads to stack traces.
stopLock sync.Mutex
shutdown bool
stopCh chan struct{}
}
type dnsControlOpts struct {
initPodCache bool
resyncPeriod time.Duration
// Label handling.
labelSelector *meta.LabelSelector
selector *labels.Selector
}
// newDNSController creates a controller for CoreDNS.
func newdnsController(kubeClient *kubernetes.Clientset, opts dnsControlOpts) *dnsControl {
dns := dnsControl{
client: kubeClient,
selector: opts.selector,
stopCh: make(chan struct{}),
}
dns.svcLister, dns.svcController = cache.NewIndexerInformer(
&cache.ListWatch{
ListFunc: serviceListFunc(dns.client, namespace, dns.selector),
WatchFunc: serviceWatchFunc(dns.client, namespace, dns.selector),
},
&api.Service{},
opts.resyncPeriod,
cache.ResourceEventHandlerFuncs{},
cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
if opts.initPodCache {
dns.podLister, dns.podController = cache.NewIndexerInformer(
&cache.ListWatch{
ListFunc: podListFunc(dns.client, namespace, dns.selector),
WatchFunc: podWatchFunc(dns.client, namespace, dns.selector),
},
&api.Pod{}, // TODO replace with a lighter-weight custom struct
opts.resyncPeriod,
cache.ResourceEventHandlerFuncs{},
cache.Indexers{podIPIndex: podIPIndexFunc})
}
dns.epLister, dns.epController = cache.NewInformer(
&cache.ListWatch{
ListFunc: endpointsListFunc(dns.client, namespace, dns.selector),
WatchFunc: endpointsWatchFunc(dns.client, namespace, dns.selector),
},
&api.Endpoints{},
opts.resyncPeriod,
cache.ResourceEventHandlerFuncs{})
return &dns
}
func podIPIndexFunc(obj interface{}) ([]string, error) {
p, ok := obj.(*api.Pod)
if !ok {
return nil, errors.New("obj was not an *api.Pod")
}
return []string{p.Status.PodIP}, nil
}
func serviceListFunc(c *kubernetes.Clientset, ns string, s *labels.Selector) func(meta.ListOptions) (runtime.Object, error) {
return func(opts meta.ListOptions) (runtime.Object, error) {
if s != nil {
opts.LabelSelector = (*s).String()
}
listV1, err := c.Services(ns).List(opts)
if err != nil {
return nil, err
}
return listV1, err
}
}
func podListFunc(c *kubernetes.Clientset, ns string, s *labels.Selector) func(meta.ListOptions) (runtime.Object, error) {
return func(opts meta.ListOptions) (runtime.Object, error) {
if s != nil {
opts.LabelSelector = (*s).String()
}
listV1, err := c.Pods(ns).List(opts)
if err != nil {
return nil, err
}
return listV1, err
}
}
func serviceWatchFunc(c *kubernetes.Clientset, ns string, s *labels.Selector) func(options meta.ListOptions) (watch.Interface, error) {
return func(options meta.ListOptions) (watch.Interface, error) {
if s != nil {
options.LabelSelector = (*s).String()
}
w, err := c.Services(ns).Watch(options)
if err != nil {
return nil, err
}
return w, nil
}
}
func podWatchFunc(c *kubernetes.Clientset, ns string, s *labels.Selector) func(options meta.ListOptions) (watch.Interface, error) {
return func(options meta.ListOptions) (watch.Interface, error) {
if s != nil {
options.LabelSelector = (*s).String()
}
w, err := c.Pods(ns).Watch(options)
if err != nil {
return nil, err
}
return w, nil
}
}
func endpointsListFunc(c *kubernetes.Clientset, ns string, s *labels.Selector) func(meta.ListOptions) (runtime.Object, error) {
return func(opts meta.ListOptions) (runtime.Object, error) {
if s != nil {
opts.LabelSelector = (*s).String()
}
listV1, err := c.Endpoints(ns).List(opts)
if err != nil {
return nil, err
}
return listV1, err
}
}
func endpointsWatchFunc(c *kubernetes.Clientset, ns string, s *labels.Selector) func(options meta.ListOptions) (watch.Interface, error) {
return func(options meta.ListOptions) (watch.Interface, error) {
if s != nil {
options.LabelSelector = (*s).String()
}
w, err := c.Endpoints(ns).Watch(options)
if err != nil {
return nil, err
}
return w, nil
}
}
func (dns *dnsControl) controllersInSync() bool {
hs := dns.svcController.HasSynced() &&
dns.epController.HasSynced()
if dns.podController != nil {
hs = hs && dns.podController.HasSynced()
}
return hs
}
// Stop stops the controller.
func (dns *dnsControl) Stop() error {
dns.stopLock.Lock()
defer dns.stopLock.Unlock()
// Only try draining the workqueue if we haven't already.
if !dns.shutdown {
close(dns.stopCh)
dns.shutdown = true
return nil
}
return fmt.Errorf("shutdown already in progress")
}
// Run starts the controller.
func (dns *dnsControl) Run() {
go dns.svcController.Run(dns.stopCh)
go dns.epController.Run(dns.stopCh)
if dns.podController != nil {
go dns.podController.Run(dns.stopCh)
}
<-dns.stopCh
}
func (dns *dnsControl) ServiceList() (svcs []*api.Service) {
os := dns.svcLister.List()
for _, o := range os {
s, ok := o.(*api.Service)
if !ok {
continue
}
svcs = append(svcs, s)
}
return svcs
}
func (dns *dnsControl) PodIndex(ip string) (pods []*api.Pod) {
if dns.podLister == nil {
return nil
}
os, err := dns.podLister.ByIndex(podIPIndex, ip)
if err != nil {
return nil
}
for _, o := range os {
p, ok := o.(*api.Pod)
if !ok {
continue
}
pods = append(pods, p)
}
return pods
}
func (dns *dnsControl) EndpointsList() (eps []*api.Endpoints) {
os := dns.epLister.List()
for _, o := range os {
ep, ok := o.(*api.Endpoints)
if !ok {
continue
}
eps = append(eps, ep)
}
return eps
}
func (dns *dnsControl) GetNodeByName(name string) (*api.Node, error) {
v1node, err := dns.client.Nodes().Get(name, meta.GetOptions{})
if err != nil {
return &api.Node{}, err
}
return v1node, nil
}
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