mirror of
https://github.com/kubernetes-sigs/external-dns.git
synced 2025-08-06 09:36:58 +02:00
550 lines
17 KiB
Go
550 lines
17 KiB
Go
/*
|
|
Copyright 2017 The Kubernetes Authors.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
package source
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"sort"
|
|
"strings"
|
|
"text/template"
|
|
|
|
kubeinformers "k8s.io/client-go/informers"
|
|
coreinformers "k8s.io/client-go/informers/core/v1"
|
|
"k8s.io/client-go/tools/cache"
|
|
|
|
log "github.com/sirupsen/logrus"
|
|
|
|
v1 "k8s.io/api/core/v1"
|
|
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
|
|
"k8s.io/apimachinery/pkg/labels"
|
|
"k8s.io/apimachinery/pkg/util/wait"
|
|
"k8s.io/client-go/kubernetes"
|
|
|
|
"time"
|
|
|
|
"github.com/kubernetes-sigs/external-dns/endpoint"
|
|
)
|
|
|
|
const (
|
|
defaultTargetsCapacity = 10
|
|
)
|
|
|
|
// serviceSource is an implementation of Source for Kubernetes service objects.
|
|
// It will find all services that are under our jurisdiction, i.e. annotated
|
|
// desired hostname and matching or no controller annotation. For each of the
|
|
// matched services' entrypoints it will return a corresponding
|
|
// Endpoint object.
|
|
type serviceSource struct {
|
|
client kubernetes.Interface
|
|
namespace string
|
|
annotationFilter string
|
|
// process Services with legacy annotations
|
|
compatibility string
|
|
fqdnTemplate *template.Template
|
|
combineFQDNAnnotation bool
|
|
ignoreHostnameAnnotation bool
|
|
publishInternal bool
|
|
publishHostIP bool
|
|
serviceInformer coreinformers.ServiceInformer
|
|
podInformer coreinformers.PodInformer
|
|
nodeInformer coreinformers.NodeInformer
|
|
serviceTypeFilter map[string]struct{}
|
|
}
|
|
|
|
// NewServiceSource creates a new serviceSource with the given config.
|
|
func NewServiceSource(kubeClient kubernetes.Interface, namespace, annotationFilter string, fqdnTemplate string, combineFqdnAnnotation bool, compatibility string, publishInternal bool, publishHostIP bool, serviceTypeFilter []string, ignoreHostnameAnnotation bool) (Source, error) {
|
|
var (
|
|
tmpl *template.Template
|
|
err error
|
|
)
|
|
if fqdnTemplate != "" {
|
|
tmpl, err = template.New("endpoint").Funcs(template.FuncMap{
|
|
"trimPrefix": strings.TrimPrefix,
|
|
}).Parse(fqdnTemplate)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
// Use shared informers to listen for add/update/delete of services/pods/nodes in the specified namespace.
|
|
// Set resync period to 0, to prevent processing when nothing has changed
|
|
informerFactory := kubeinformers.NewSharedInformerFactoryWithOptions(kubeClient, 0, kubeinformers.WithNamespace(namespace))
|
|
serviceInformer := informerFactory.Core().V1().Services()
|
|
podInformer := informerFactory.Core().V1().Pods()
|
|
nodeInformer := informerFactory.Core().V1().Nodes()
|
|
|
|
// Add default resource event handlers to properly initialize informer.
|
|
serviceInformer.Informer().AddEventHandler(
|
|
cache.ResourceEventHandlerFuncs{
|
|
AddFunc: func(obj interface{}) {
|
|
log.Debug("service added")
|
|
},
|
|
},
|
|
)
|
|
podInformer.Informer().AddEventHandler(
|
|
cache.ResourceEventHandlerFuncs{
|
|
AddFunc: func(obj interface{}) {
|
|
log.Debug("pod added")
|
|
},
|
|
},
|
|
)
|
|
nodeInformer.Informer().AddEventHandler(
|
|
cache.ResourceEventHandlerFuncs{
|
|
AddFunc: func(obj interface{}) {
|
|
log.Debug("node added")
|
|
},
|
|
},
|
|
)
|
|
|
|
// TODO informer is not explicitly stopped since controller is not passing in its channel.
|
|
informerFactory.Start(wait.NeverStop)
|
|
|
|
// wait for the local cache to be populated.
|
|
err = wait.Poll(time.Second, 60*time.Second, func() (bool, error) {
|
|
return serviceInformer.Informer().HasSynced() == true, nil
|
|
})
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to sync cache: %v", err)
|
|
}
|
|
|
|
// Transform the slice into a map so it will
|
|
// be way much easier and fast to filter later
|
|
serviceTypes := make(map[string]struct{})
|
|
for _, serviceType := range serviceTypeFilter {
|
|
serviceTypes[serviceType] = struct{}{}
|
|
}
|
|
|
|
return &serviceSource{
|
|
client: kubeClient,
|
|
namespace: namespace,
|
|
annotationFilter: annotationFilter,
|
|
compatibility: compatibility,
|
|
fqdnTemplate: tmpl,
|
|
combineFQDNAnnotation: combineFqdnAnnotation,
|
|
ignoreHostnameAnnotation: ignoreHostnameAnnotation,
|
|
publishInternal: publishInternal,
|
|
publishHostIP: publishHostIP,
|
|
serviceInformer: serviceInformer,
|
|
podInformer: podInformer,
|
|
nodeInformer: nodeInformer,
|
|
serviceTypeFilter: serviceTypes,
|
|
}, nil
|
|
}
|
|
|
|
// Endpoints returns endpoint objects for each service that should be processed.
|
|
func (sc *serviceSource) Endpoints() ([]*endpoint.Endpoint, error) {
|
|
services, err := sc.serviceInformer.Lister().Services(sc.namespace).List(labels.Everything())
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
services, err = sc.filterByAnnotations(services)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// filter on service types if at least one has been provided
|
|
if len(sc.serviceTypeFilter) > 0 {
|
|
services = sc.filterByServiceType(services)
|
|
}
|
|
|
|
endpoints := []*endpoint.Endpoint{}
|
|
|
|
for _, svc := range services {
|
|
// Check controller annotation to see if we are responsible.
|
|
controller, ok := svc.Annotations[controllerAnnotationKey]
|
|
if ok && controller != controllerAnnotationValue {
|
|
log.Debugf("Skipping service %s/%s because controller value does not match, found: %s, required: %s",
|
|
svc.Namespace, svc.Name, controller, controllerAnnotationValue)
|
|
continue
|
|
}
|
|
|
|
svcEndpoints := sc.endpoints(svc)
|
|
|
|
// process legacy annotations if no endpoints were returned and compatibility mode is enabled.
|
|
if len(svcEndpoints) == 0 && sc.compatibility != "" {
|
|
svcEndpoints = legacyEndpointsFromService(svc, sc.compatibility)
|
|
}
|
|
|
|
// apply template if none of the above is found
|
|
if (sc.combineFQDNAnnotation || len(svcEndpoints) == 0) && sc.fqdnTemplate != nil {
|
|
sEndpoints, err := sc.endpointsFromTemplate(svc)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if sc.combineFQDNAnnotation {
|
|
svcEndpoints = append(svcEndpoints, sEndpoints...)
|
|
} else {
|
|
svcEndpoints = sEndpoints
|
|
}
|
|
}
|
|
|
|
if len(svcEndpoints) == 0 {
|
|
log.Debugf("No endpoints could be generated from service %s/%s", svc.Namespace, svc.Name)
|
|
continue
|
|
}
|
|
|
|
log.Debugf("Endpoints generated from service: %s/%s: %v", svc.Namespace, svc.Name, svcEndpoints)
|
|
sc.setResourceLabel(svc, svcEndpoints)
|
|
endpoints = append(endpoints, svcEndpoints...)
|
|
}
|
|
|
|
for _, ep := range endpoints {
|
|
sort.Sort(ep.Targets)
|
|
}
|
|
|
|
return endpoints, nil
|
|
}
|
|
|
|
func (sc *serviceSource) extractHeadlessEndpoints(svc *v1.Service, hostname string, ttl endpoint.TTL) []*endpoint.Endpoint {
|
|
var endpoints []*endpoint.Endpoint
|
|
|
|
labelSelector, err := metav1.ParseToLabelSelector(labels.Set(svc.Spec.Selector).AsSelectorPreValidated().String())
|
|
if err != nil {
|
|
return nil
|
|
}
|
|
selector, err := metav1.LabelSelectorAsSelector(labelSelector)
|
|
if err != nil {
|
|
return nil
|
|
}
|
|
|
|
pods, err := sc.podInformer.Lister().Pods(svc.Namespace).List(selector)
|
|
if err != nil {
|
|
log.Errorf("List Pods of service[%s] error:%v", svc.GetName(), err)
|
|
return endpoints
|
|
}
|
|
|
|
targetsByHeadlessDomain := make(map[string][]string)
|
|
for _, v := range pods {
|
|
headlessDomains := []string{hostname}
|
|
|
|
if v.Spec.Hostname != "" {
|
|
headlessDomains = append(headlessDomains, fmt.Sprintf("%s.%s", v.Spec.Hostname, hostname))
|
|
}
|
|
for _, headlessDomain := range headlessDomains {
|
|
if sc.publishHostIP == true {
|
|
log.Debugf("Generating matching endpoint %s with HostIP %s", headlessDomain, v.Status.HostIP)
|
|
// To reduce traffice on the DNS API only add record for running Pods. Good Idea?
|
|
if v.Status.Phase == v1.PodRunning {
|
|
targetsByHeadlessDomain[headlessDomain] = append(targetsByHeadlessDomain[headlessDomain], v.Status.HostIP)
|
|
} else {
|
|
log.Debugf("Pod %s is not in running phase", v.Spec.Hostname)
|
|
}
|
|
} else {
|
|
log.Debugf("Generating matching endpoint %s with PodIP %s", headlessDomain, v.Status.PodIP)
|
|
// To reduce traffice on the DNS API only add record for running Pods. Good Idea?
|
|
if v.Status.Phase == v1.PodRunning {
|
|
targetsByHeadlessDomain[headlessDomain] = append(targetsByHeadlessDomain[headlessDomain], v.Status.PodIP)
|
|
} else {
|
|
log.Debugf("Pod %s is not in running phase", v.Spec.Hostname)
|
|
}
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
headlessDomains := []string{}
|
|
for headlessDomain := range targetsByHeadlessDomain {
|
|
headlessDomains = append(headlessDomains, headlessDomain)
|
|
}
|
|
sort.Strings(headlessDomains)
|
|
for _, headlessDomain := range headlessDomains {
|
|
targets := targetsByHeadlessDomain[headlessDomain]
|
|
if ttl.IsConfigured() {
|
|
endpoints = append(endpoints, endpoint.NewEndpointWithTTL(headlessDomain, endpoint.RecordTypeA, ttl, targets...))
|
|
} else {
|
|
endpoints = append(endpoints, endpoint.NewEndpoint(headlessDomain, endpoint.RecordTypeA, targets...))
|
|
}
|
|
}
|
|
|
|
return endpoints
|
|
}
|
|
|
|
func (sc *serviceSource) endpointsFromTemplate(svc *v1.Service) ([]*endpoint.Endpoint, error) {
|
|
var endpoints []*endpoint.Endpoint
|
|
|
|
// Process the whole template string
|
|
var buf bytes.Buffer
|
|
err := sc.fqdnTemplate.Execute(&buf, svc)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to apply template on service %s: %v", svc.String(), err)
|
|
}
|
|
|
|
providerSpecific := getProviderSpecificAnnotations(svc.Annotations)
|
|
hostnameList := strings.Split(strings.Replace(buf.String(), " ", "", -1), ",")
|
|
for _, hostname := range hostnameList {
|
|
endpoints = append(endpoints, sc.generateEndpoints(svc, hostname, providerSpecific)...)
|
|
}
|
|
|
|
return endpoints, nil
|
|
}
|
|
|
|
// endpointsFromService extracts the endpoints from a service object
|
|
func (sc *serviceSource) endpoints(svc *v1.Service) []*endpoint.Endpoint {
|
|
var endpoints []*endpoint.Endpoint
|
|
// Skip endpoints if we do not want entries from annotations
|
|
if !sc.ignoreHostnameAnnotation {
|
|
providerSpecific := getProviderSpecificAnnotations(svc.Annotations)
|
|
hostnameList := getHostnamesFromAnnotations(svc.Annotations)
|
|
for _, hostname := range hostnameList {
|
|
endpoints = append(endpoints, sc.generateEndpoints(svc, hostname, providerSpecific)...)
|
|
}
|
|
}
|
|
return endpoints
|
|
}
|
|
|
|
// filterByAnnotations filters a list of services by a given annotation selector.
|
|
func (sc *serviceSource) filterByAnnotations(services []*v1.Service) ([]*v1.Service, error) {
|
|
labelSelector, err := metav1.ParseToLabelSelector(sc.annotationFilter)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
selector, err := metav1.LabelSelectorAsSelector(labelSelector)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// empty filter returns original list
|
|
if selector.Empty() {
|
|
return services, nil
|
|
}
|
|
|
|
filteredList := []*v1.Service{}
|
|
|
|
for _, service := range services {
|
|
// convert the service's annotations to an equivalent label selector
|
|
annotations := labels.Set(service.Annotations)
|
|
|
|
// include service if its annotations match the selector
|
|
if selector.Matches(annotations) {
|
|
filteredList = append(filteredList, service)
|
|
}
|
|
}
|
|
|
|
return filteredList, nil
|
|
}
|
|
|
|
// filterByServiceType filters services according their types
|
|
func (sc *serviceSource) filterByServiceType(services []*v1.Service) []*v1.Service {
|
|
filteredList := []*v1.Service{}
|
|
for _, service := range services {
|
|
// Check if the service is of the given type or not
|
|
if _, ok := sc.serviceTypeFilter[string(service.Spec.Type)]; ok {
|
|
filteredList = append(filteredList, service)
|
|
}
|
|
}
|
|
|
|
return filteredList
|
|
}
|
|
|
|
func (sc *serviceSource) setResourceLabel(service *v1.Service, endpoints []*endpoint.Endpoint) {
|
|
for _, ep := range endpoints {
|
|
ep.Labels[endpoint.ResourceLabelKey] = fmt.Sprintf("service/%s/%s", service.Namespace, service.Name)
|
|
}
|
|
}
|
|
|
|
func (sc *serviceSource) generateEndpoints(svc *v1.Service, hostname string, providerSpecific endpoint.ProviderSpecific) []*endpoint.Endpoint {
|
|
hostname = strings.TrimSuffix(hostname, ".")
|
|
ttl, err := getTTLFromAnnotations(svc.Annotations)
|
|
if err != nil {
|
|
log.Warn(err)
|
|
}
|
|
|
|
epA := &endpoint.Endpoint{
|
|
RecordTTL: ttl,
|
|
RecordType: endpoint.RecordTypeA,
|
|
Labels: endpoint.NewLabels(),
|
|
Targets: make(endpoint.Targets, 0, defaultTargetsCapacity),
|
|
DNSName: hostname,
|
|
ProviderSpecific: providerSpecific,
|
|
}
|
|
|
|
epCNAME := &endpoint.Endpoint{
|
|
RecordTTL: ttl,
|
|
RecordType: endpoint.RecordTypeCNAME,
|
|
Labels: endpoint.NewLabels(),
|
|
Targets: make(endpoint.Targets, 0, defaultTargetsCapacity),
|
|
DNSName: hostname,
|
|
ProviderSpecific: providerSpecific,
|
|
}
|
|
|
|
var endpoints []*endpoint.Endpoint
|
|
var targets endpoint.Targets
|
|
|
|
switch svc.Spec.Type {
|
|
case v1.ServiceTypeLoadBalancer:
|
|
targets = append(targets, extractLoadBalancerTargets(svc)...)
|
|
case v1.ServiceTypeClusterIP:
|
|
if sc.publishInternal {
|
|
targets = append(targets, extractServiceIps(svc)...)
|
|
}
|
|
if svc.Spec.ClusterIP == v1.ClusterIPNone {
|
|
endpoints = append(endpoints, sc.extractHeadlessEndpoints(svc, hostname, ttl)...)
|
|
}
|
|
case v1.ServiceTypeNodePort:
|
|
// add the nodeTargets and extract an SRV endpoint
|
|
targets, err = sc.extractNodePortTargets(svc)
|
|
if err != nil {
|
|
log.Errorf("Unable to extract targets from service %s/%s error: %v", svc.Namespace, svc.Name, err)
|
|
return endpoints
|
|
}
|
|
endpoints = append(endpoints, sc.extractNodePortEndpoints(svc, targets, hostname, ttl)...)
|
|
case v1.ServiceTypeExternalName:
|
|
targets = append(targets, extractServiceExternalName(svc)...)
|
|
}
|
|
|
|
for _, t := range targets {
|
|
if suitableType(t) == endpoint.RecordTypeA {
|
|
epA.Targets = append(epA.Targets, t)
|
|
}
|
|
if suitableType(t) == endpoint.RecordTypeCNAME {
|
|
epCNAME.Targets = append(epCNAME.Targets, t)
|
|
}
|
|
}
|
|
|
|
if len(epA.Targets) > 0 {
|
|
endpoints = append(endpoints, epA)
|
|
}
|
|
if len(epCNAME.Targets) > 0 {
|
|
endpoints = append(endpoints, epCNAME)
|
|
}
|
|
return endpoints
|
|
}
|
|
|
|
func extractServiceIps(svc *v1.Service) endpoint.Targets {
|
|
if svc.Spec.ClusterIP == v1.ClusterIPNone {
|
|
log.Debugf("Unable to associate %s headless service with a Cluster IP", svc.Name)
|
|
return endpoint.Targets{}
|
|
}
|
|
return endpoint.Targets{svc.Spec.ClusterIP}
|
|
}
|
|
|
|
func extractServiceExternalName(svc *v1.Service) endpoint.Targets {
|
|
return endpoint.Targets{svc.Spec.ExternalName}
|
|
}
|
|
|
|
func extractLoadBalancerTargets(svc *v1.Service) endpoint.Targets {
|
|
var targets endpoint.Targets
|
|
|
|
// Create a corresponding endpoint for each configured external entrypoint.
|
|
for _, lb := range svc.Status.LoadBalancer.Ingress {
|
|
if lb.IP != "" {
|
|
targets = append(targets, lb.IP)
|
|
}
|
|
if lb.Hostname != "" {
|
|
targets = append(targets, lb.Hostname)
|
|
}
|
|
}
|
|
|
|
return targets
|
|
}
|
|
|
|
func (sc *serviceSource) extractNodePortTargets(svc *v1.Service) (endpoint.Targets, error) {
|
|
var (
|
|
internalIPs endpoint.Targets
|
|
externalIPs endpoint.Targets
|
|
nodes []*v1.Node
|
|
err error
|
|
)
|
|
|
|
switch svc.Spec.ExternalTrafficPolicy {
|
|
case v1.ServiceExternalTrafficPolicyTypeLocal:
|
|
labelSelector, err := metav1.ParseToLabelSelector(labels.Set(svc.Spec.Selector).AsSelectorPreValidated().String())
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
selector, err := metav1.LabelSelectorAsSelector(labelSelector)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
pods, err := sc.podInformer.Lister().Pods(svc.Namespace).List(selector)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
for _, v := range pods {
|
|
if v.Status.Phase == v1.PodRunning {
|
|
node, err := sc.nodeInformer.Lister().Get(v.Spec.NodeName)
|
|
if err != nil {
|
|
log.Debugf("Unable to find node where Pod %s is running", v.Spec.Hostname)
|
|
continue
|
|
}
|
|
nodes = append(nodes, node)
|
|
}
|
|
}
|
|
default:
|
|
nodes, err = sc.nodeInformer.Lister().List(labels.Everything())
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
for _, node := range nodes {
|
|
for _, address := range node.Status.Addresses {
|
|
switch address.Type {
|
|
case v1.NodeExternalIP:
|
|
externalIPs = append(externalIPs, address.Address)
|
|
case v1.NodeInternalIP:
|
|
internalIPs = append(internalIPs, address.Address)
|
|
}
|
|
}
|
|
}
|
|
|
|
if len(externalIPs) > 0 {
|
|
return externalIPs, nil
|
|
}
|
|
|
|
return internalIPs, nil
|
|
}
|
|
|
|
func (sc *serviceSource) extractNodePortEndpoints(svc *v1.Service, nodeTargets endpoint.Targets, hostname string, ttl endpoint.TTL) []*endpoint.Endpoint {
|
|
var endpoints []*endpoint.Endpoint
|
|
|
|
for _, port := range svc.Spec.Ports {
|
|
if port.NodePort > 0 {
|
|
// build a target with a priority of 0, weight of 0, and pointing the given port on the given host
|
|
target := fmt.Sprintf("0 50 %d %s", port.NodePort, hostname)
|
|
|
|
// figure out the portname
|
|
portName := port.Name
|
|
if portName == "" {
|
|
portName = fmt.Sprintf("%d", port.NodePort)
|
|
}
|
|
|
|
// figure out the protocol
|
|
protocol := strings.ToLower(string(port.Protocol))
|
|
if protocol == "" {
|
|
protocol = "tcp"
|
|
}
|
|
|
|
recordName := fmt.Sprintf("_%s._%s.%s", portName, protocol, hostname)
|
|
|
|
var ep *endpoint.Endpoint
|
|
if ttl.IsConfigured() {
|
|
ep = endpoint.NewEndpointWithTTL(recordName, endpoint.RecordTypeSRV, ttl, target)
|
|
} else {
|
|
ep = endpoint.NewEndpoint(recordName, endpoint.RecordTypeSRV, target)
|
|
}
|
|
|
|
endpoints = append(endpoints, ep)
|
|
}
|
|
}
|
|
|
|
return endpoints
|
|
}
|