traefik/pkg/provider/kubernetes/ingress/client.go
2020-02-25 15:14:04 +01:00

292 lines
9.8 KiB
Go

package ingress
import (
"errors"
"fmt"
"io/ioutil"
"time"
"github.com/containous/traefik/v2/pkg/log"
corev1 "k8s.io/api/core/v1"
extensionsv1beta1 "k8s.io/api/extensions/v1beta1"
kubeerror "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/client-go/informers"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/rest"
"k8s.io/client-go/tools/cache"
"k8s.io/client-go/tools/clientcmd"
)
const resyncPeriod = 10 * time.Minute
type resourceEventHandler struct {
ev chan<- interface{}
}
func (reh *resourceEventHandler) OnAdd(obj interface{}) {
eventHandlerFunc(reh.ev, obj)
}
func (reh *resourceEventHandler) OnUpdate(oldObj, newObj interface{}) {
eventHandlerFunc(reh.ev, newObj)
}
func (reh *resourceEventHandler) OnDelete(obj interface{}) {
eventHandlerFunc(reh.ev, obj)
}
// Client is a client for the Provider master.
// WatchAll starts the watch of the Provider resources and updates the stores.
// The stores can then be accessed via the Get* functions.
type Client interface {
WatchAll(namespaces []string, stopCh <-chan struct{}) (<-chan interface{}, error)
GetIngresses() []*extensionsv1beta1.Ingress
GetService(namespace, name string) (*corev1.Service, bool, error)
GetSecret(namespace, name string) (*corev1.Secret, bool, error)
GetEndpoints(namespace, name string) (*corev1.Endpoints, bool, error)
UpdateIngressStatus(namespace, name, ip, hostname string) error
}
type clientWrapper struct {
clientset *kubernetes.Clientset
factories map[string]informers.SharedInformerFactory
ingressLabelSelector labels.Selector
isNamespaceAll bool
watchedNamespaces []string
}
// newInClusterClient returns a new Provider client that is expected to run
// inside the cluster.
func newInClusterClient(endpoint string) (*clientWrapper, error) {
config, err := rest.InClusterConfig()
if err != nil {
return nil, fmt.Errorf("failed to create in-cluster configuration: %s", err)
}
if endpoint != "" {
config.Host = endpoint
}
return createClientFromConfig(config)
}
func newExternalClusterClientFromFile(file string) (*clientWrapper, error) {
configFromFlags, err := clientcmd.BuildConfigFromFlags("", file)
if err != nil {
return nil, err
}
return createClientFromConfig(configFromFlags)
}
// newExternalClusterClient returns a new Provider client that may run outside
// of the cluster.
// The endpoint parameter must not be empty.
func newExternalClusterClient(endpoint, token, caFilePath string) (*clientWrapper, error) {
if endpoint == "" {
return nil, errors.New("endpoint missing for external cluster client")
}
config := &rest.Config{
Host: endpoint,
BearerToken: token,
}
if caFilePath != "" {
caData, err := ioutil.ReadFile(caFilePath)
if err != nil {
return nil, fmt.Errorf("failed to read CA file %s: %s", caFilePath, err)
}
config.TLSClientConfig = rest.TLSClientConfig{CAData: caData}
}
return createClientFromConfig(config)
}
func createClientFromConfig(c *rest.Config) (*clientWrapper, error) {
clientset, err := kubernetes.NewForConfig(c)
if err != nil {
return nil, err
}
return newClientImpl(clientset), nil
}
func newClientImpl(clientset *kubernetes.Clientset) *clientWrapper {
return &clientWrapper{
clientset: clientset,
factories: make(map[string]informers.SharedInformerFactory),
}
}
// WatchAll starts namespace-specific controllers for all relevant kinds.
func (c *clientWrapper) WatchAll(namespaces []string, stopCh <-chan struct{}) (<-chan interface{}, error) {
eventCh := make(chan interface{}, 1)
eventHandler := c.newResourceEventHandler(eventCh)
if len(namespaces) == 0 {
namespaces = []string{metav1.NamespaceAll}
c.isNamespaceAll = true
}
c.watchedNamespaces = namespaces
for _, ns := range namespaces {
factory := informers.NewFilteredSharedInformerFactory(c.clientset, resyncPeriod, ns, nil)
factory.Extensions().V1beta1().Ingresses().Informer().AddEventHandler(eventHandler)
factory.Core().V1().Services().Informer().AddEventHandler(eventHandler)
factory.Core().V1().Endpoints().Informer().AddEventHandler(eventHandler)
factory.Core().V1().Secrets().Informer().AddEventHandler(eventHandler)
c.factories[ns] = factory
}
for _, ns := range namespaces {
c.factories[ns].Start(stopCh)
}
for _, ns := range namespaces {
for t, ok := range c.factories[ns].WaitForCacheSync(stopCh) {
if !ok {
return nil, fmt.Errorf("timed out waiting for controller caches to sync %s in namespace %q", t.String(), ns)
}
}
}
return eventCh, nil
}
// GetIngresses returns all Ingresses for observed namespaces in the cluster.
func (c *clientWrapper) GetIngresses() []*extensionsv1beta1.Ingress {
var result []*extensionsv1beta1.Ingress
for ns, factory := range c.factories {
ings, err := factory.Extensions().V1beta1().Ingresses().Lister().List(c.ingressLabelSelector)
if err != nil {
log.Errorf("Failed to list ingresses in namespace %s: %s", ns, err)
}
result = append(result, ings...)
}
return result
}
// UpdateIngressStatus updates an Ingress with a provided status.
func (c *clientWrapper) UpdateIngressStatus(namespace, name, ip, hostname string) error {
if !c.isWatchedNamespace(namespace) {
return fmt.Errorf("failed to get ingress %s/%s: namespace is not within watched namespaces", namespace, name)
}
ing, err := c.factories[c.lookupNamespace(namespace)].Extensions().V1beta1().Ingresses().Lister().Ingresses(namespace).Get(name)
if err != nil {
return fmt.Errorf("failed to get ingress %s/%s: %v", namespace, name, err)
}
if len(ing.Status.LoadBalancer.Ingress) > 0 {
if ing.Status.LoadBalancer.Ingress[0].Hostname == hostname && ing.Status.LoadBalancer.Ingress[0].IP == ip {
// If status is already set, skip update
log.Debugf("Skipping status update on ingress %s/%s", ing.Namespace, ing.Name)
return nil
}
}
ingCopy := ing.DeepCopy()
ingCopy.Status = extensionsv1beta1.IngressStatus{LoadBalancer: corev1.LoadBalancerStatus{Ingress: []corev1.LoadBalancerIngress{{IP: ip, Hostname: hostname}}}}
_, err = c.clientset.ExtensionsV1beta1().Ingresses(ingCopy.Namespace).UpdateStatus(ingCopy)
if err != nil {
return fmt.Errorf("failed to update ingress status %s/%s: %v", namespace, name, err)
}
log.Infof("Updated status on ingress %s/%s", namespace, name)
return nil
}
// GetService returns the named service from the given namespace.
func (c *clientWrapper) GetService(namespace, name string) (*corev1.Service, bool, error) {
if !c.isWatchedNamespace(namespace) {
return nil, false, fmt.Errorf("failed to get service %s/%s: namespace is not within watched namespaces", namespace, name)
}
service, err := c.factories[c.lookupNamespace(namespace)].Core().V1().Services().Lister().Services(namespace).Get(name)
exist, err := translateNotFoundError(err)
return service, exist, err
}
// GetEndpoints returns the named endpoints from the given namespace.
func (c *clientWrapper) GetEndpoints(namespace, name string) (*corev1.Endpoints, bool, error) {
if !c.isWatchedNamespace(namespace) {
return nil, false, fmt.Errorf("failed to get endpoints %s/%s: namespace is not within watched namespaces", namespace, name)
}
endpoint, err := c.factories[c.lookupNamespace(namespace)].Core().V1().Endpoints().Lister().Endpoints(namespace).Get(name)
exist, err := translateNotFoundError(err)
return endpoint, exist, err
}
// GetSecret returns the named secret from the given namespace.
func (c *clientWrapper) GetSecret(namespace, name string) (*corev1.Secret, bool, error) {
if !c.isWatchedNamespace(namespace) {
return nil, false, fmt.Errorf("failed to get secret %s/%s: namespace is not within watched namespaces", namespace, name)
}
secret, err := c.factories[c.lookupNamespace(namespace)].Core().V1().Secrets().Lister().Secrets(namespace).Get(name)
exist, err := translateNotFoundError(err)
return secret, exist, err
}
// lookupNamespace returns the lookup namespace key for the given namespace.
// When listening on all namespaces, it returns the client-go identifier ("")
// for all-namespaces. Otherwise, it returns the given namespace.
// The distinction is necessary because we index all informers on the special
// identifier iff all-namespaces are requested but receive specific namespace
// identifiers from the Kubernetes API, so we have to bridge this gap.
func (c *clientWrapper) lookupNamespace(ns string) string {
if c.isNamespaceAll {
return metav1.NamespaceAll
}
return ns
}
func (c *clientWrapper) newResourceEventHandler(events chan<- interface{}) cache.ResourceEventHandler {
return &cache.FilteringResourceEventHandler{
FilterFunc: func(obj interface{}) bool {
// Ignore Ingresses that do not match our custom label selector.
if ing, ok := obj.(*extensionsv1beta1.Ingress); ok {
lbls := labels.Set(ing.GetLabels())
return c.ingressLabelSelector.Matches(lbls)
}
return true
},
Handler: &resourceEventHandler{ev: events},
}
}
// eventHandlerFunc will pass the obj on to the events channel or drop it.
// This is so passing the events along won't block in the case of high volume.
// The events are only used for signaling anyway so dropping a few is ok.
func eventHandlerFunc(events chan<- interface{}, obj interface{}) {
select {
case events <- obj:
default:
}
}
// translateNotFoundError will translate a "not found" error to a boolean return
// value which indicates if the resource exists and a nil error.
func translateNotFoundError(err error) (bool, error) {
if kubeerror.IsNotFound(err) {
return false, nil
}
return err == nil, err
}
// isWatchedNamespace checks to ensure that the namespace is being watched before we request
// it to ensure we don't panic by requesting an out-of-watch object.
func (c *clientWrapper) isWatchedNamespace(ns string) bool {
if c.isNamespaceAll {
return true
}
for _, watchedNamespace := range c.watchedNamespaces {
if watchedNamespace == ns {
return true
}
}
return false
}