920b5bb15d
Detect whether in-cluster or cluster-external Kubernetes client should
be used based on the KUBERNETES_SERVICE_{HOST,PORT} environment
variables.
Adds bearer token and CA certificate file path parameters.
345 lines
11 KiB
Go
345 lines
11 KiB
Go
package provider
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import (
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"fmt"
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"os"
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"reflect"
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"strconv"
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"strings"
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"text/template"
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"time"
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"github.com/cenk/backoff"
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"github.com/containous/traefik/job"
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"github.com/containous/traefik/log"
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"github.com/containous/traefik/provider/k8s"
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"github.com/containous/traefik/safe"
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"github.com/containous/traefik/types"
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"k8s.io/client-go/1.5/pkg/api/v1"
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"k8s.io/client-go/1.5/pkg/util/intstr"
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)
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var _ Provider = (*Kubernetes)(nil)
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const (
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annotationFrontendRuleType = "traefik.frontend.rule.type"
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ruleTypePathPrefixStrip = "PathPrefixStrip"
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ruleTypePathStrip = "PathStrip"
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ruleTypePath = "Path"
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ruleTypePathPrefix = "PathPrefix"
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)
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// Kubernetes holds configurations of the Kubernetes provider.
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type Kubernetes struct {
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BaseProvider `mapstructure:",squash"`
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Endpoint string `description:"Kubernetes server endpoint (required for external cluster client)"`
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Token string `description:"Kubernetes bearer token (not needed for in-cluster client)"`
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CertAuthFilePath string `description:"Kubernetes certificate authority file path (not needed for in-cluster client)"`
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DisablePassHostHeaders bool `description:"Kubernetes disable PassHost Headers"`
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Namespaces k8s.Namespaces `description:"Kubernetes namespaces"`
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LabelSelector string `description:"Kubernetes api label selector to use"`
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lastConfiguration safe.Safe
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}
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func (provider *Kubernetes) newK8sClient() (k8s.Client, error) {
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withEndpoint := ""
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if provider.Endpoint != "" {
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withEndpoint = fmt.Sprintf(" with endpoint %v", provider.Endpoint)
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}
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if os.Getenv("KUBERNETES_SERVICE_HOST") != "" && os.Getenv("KUBERNETES_SERVICE_PORT") != "" {
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log.Infof("Creating in-cluster Kubernetes client%s\n", withEndpoint)
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return k8s.NewInClusterClient(provider.Endpoint)
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}
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log.Infof("Creating cluster-external Kubernetes client%s\n", withEndpoint)
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return k8s.NewExternalClusterClient(provider.Endpoint, provider.Token, provider.CertAuthFilePath)
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}
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// Provide allows the provider to provide configurations to traefik
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// using the given configuration channel.
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func (provider *Kubernetes) Provide(configurationChan chan<- types.ConfigMessage, pool *safe.Pool, constraints types.Constraints) error {
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k8sClient, err := provider.newK8sClient()
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if err != nil {
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return err
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}
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provider.Constraints = append(provider.Constraints, constraints...)
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pool.Go(func(stop chan bool) {
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operation := func() error {
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for {
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stopWatch := make(chan struct{}, 1)
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defer close(stopWatch)
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log.Debugf("Using label selector: '%s'", provider.LabelSelector)
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eventsChan, err := k8sClient.WatchAll(provider.LabelSelector, stopWatch)
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if err != nil {
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log.Errorf("Error watching kubernetes events: %v", err)
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timer := time.NewTimer(1 * time.Second)
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select {
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case <-timer.C:
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return err
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case <-stop:
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return nil
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}
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}
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for {
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select {
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case <-stop:
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return nil
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case event := <-eventsChan:
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log.Debugf("Received event from kubernetes %+v", event)
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templateObjects, err := provider.loadIngresses(k8sClient)
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if err != nil {
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return err
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}
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if reflect.DeepEqual(provider.lastConfiguration.Get(), templateObjects) {
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log.Debugf("Skipping event from kubernetes %+v", event)
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} else {
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provider.lastConfiguration.Set(templateObjects)
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configurationChan <- types.ConfigMessage{
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ProviderName: "kubernetes",
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Configuration: provider.loadConfig(*templateObjects),
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}
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}
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}
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}
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}
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}
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notify := func(err error, time time.Duration) {
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log.Errorf("Kubernetes connection error %+v, retrying in %s", err, time)
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}
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err := backoff.RetryNotify(safe.OperationWithRecover(operation), job.NewBackOff(backoff.NewExponentialBackOff()), notify)
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if err != nil {
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log.Errorf("Cannot connect to Kubernetes server %+v", err)
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}
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})
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return nil
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}
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func (provider *Kubernetes) loadIngresses(k8sClient k8s.Client) (*types.Configuration, error) {
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ingresses := k8sClient.GetIngresses(provider.Namespaces)
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templateObjects := types.Configuration{
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map[string]*types.Backend{},
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map[string]*types.Frontend{},
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}
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for _, i := range ingresses {
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ingressClass := i.Annotations["kubernetes.io/ingress.class"]
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if !shouldProcessIngress(ingressClass) {
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continue
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}
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for _, r := range i.Spec.Rules {
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if r.HTTP == nil {
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log.Warnf("Error in ingress: HTTP is nil")
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continue
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}
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for _, pa := range r.HTTP.Paths {
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if _, exists := templateObjects.Backends[r.Host+pa.Path]; !exists {
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templateObjects.Backends[r.Host+pa.Path] = &types.Backend{
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Servers: make(map[string]types.Server),
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LoadBalancer: &types.LoadBalancer{
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Sticky: false,
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Method: "wrr",
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},
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}
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}
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PassHostHeader := provider.getPassHostHeader()
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passHostHeaderAnnotation := i.Annotations["traefik.frontend.passHostHeader"]
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switch passHostHeaderAnnotation {
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case "true":
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PassHostHeader = true
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case "false":
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PassHostHeader = false
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default:
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log.Warnf("Unknown value of %s for traefik.frontend.passHostHeader, falling back to %s", passHostHeaderAnnotation, PassHostHeader)
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}
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if _, exists := templateObjects.Frontends[r.Host+pa.Path]; !exists {
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templateObjects.Frontends[r.Host+pa.Path] = &types.Frontend{
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Backend: r.Host + pa.Path,
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PassHostHeader: PassHostHeader,
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Routes: make(map[string]types.Route),
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Priority: len(pa.Path),
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}
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}
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if len(r.Host) > 0 {
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rule := "Host:" + r.Host
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if strings.Contains(r.Host, "*") {
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rule = "HostRegexp:" + strings.Replace(r.Host, "*", "{subdomain:[A-Za-z0-9-_]+}", 1)
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}
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if _, exists := templateObjects.Frontends[r.Host+pa.Path].Routes[r.Host]; !exists {
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templateObjects.Frontends[r.Host+pa.Path].Routes[r.Host] = types.Route{
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Rule: rule,
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}
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}
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}
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if len(pa.Path) > 0 {
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ruleType, unknown := getRuleTypeFromAnnotation(i.Annotations)
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switch {
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case unknown:
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log.Warnf("Unknown RuleType '%s' for Ingress %s/%s, falling back to PathPrefix", ruleType, i.ObjectMeta.Namespace, i.ObjectMeta.Name)
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fallthrough
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case ruleType == "":
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ruleType = ruleTypePathPrefix
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}
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templateObjects.Frontends[r.Host+pa.Path].Routes[pa.Path] = types.Route{
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Rule: ruleType + ":" + pa.Path,
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}
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}
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service, exists, err := k8sClient.GetService(i.ObjectMeta.Namespace, pa.Backend.ServiceName)
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if err != nil || !exists {
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log.Warnf("Error retrieving service %s/%s: %v", i.ObjectMeta.Namespace, pa.Backend.ServiceName, err)
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delete(templateObjects.Frontends, r.Host+pa.Path)
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continue
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}
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if expression := service.Annotations["traefik.backend.circuitbreaker"]; expression != "" {
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templateObjects.Backends[r.Host+pa.Path].CircuitBreaker = &types.CircuitBreaker{
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Expression: expression,
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}
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}
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if service.Annotations["traefik.backend.loadbalancer.method"] == "drr" {
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templateObjects.Backends[r.Host+pa.Path].LoadBalancer.Method = "drr"
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}
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if service.Annotations["traefik.backend.loadbalancer.sticky"] == "true" {
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templateObjects.Backends[r.Host+pa.Path].LoadBalancer.Sticky = true
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}
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protocol := "http"
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for _, port := range service.Spec.Ports {
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if equalPorts(port, pa.Backend.ServicePort) {
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if port.Port == 443 {
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protocol = "https"
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}
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if service.Spec.Type == "ExternalName" {
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url := protocol + "://" + service.Spec.ExternalName
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name := url
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templateObjects.Backends[r.Host+pa.Path].Servers[name] = types.Server{
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URL: url,
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Weight: 1,
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}
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} else {
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endpoints, exists, err := k8sClient.GetEndpoints(service.ObjectMeta.Namespace, service.ObjectMeta.Name)
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if err != nil {
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log.Errorf("Error while retrieving endpoints from k8s API %s/%s: %v", service.ObjectMeta.Namespace, service.ObjectMeta.Name, err)
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continue
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}
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if !exists {
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log.Errorf("Service not found for %s/%s", service.ObjectMeta.Namespace, service.ObjectMeta.Name)
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continue
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}
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if len(endpoints.Subsets) == 0 {
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log.Warnf("Endpoints not found for %s/%s, falling back to Service ClusterIP", service.ObjectMeta.Namespace, service.ObjectMeta.Name)
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templateObjects.Backends[r.Host+pa.Path].Servers[string(service.UID)] = types.Server{
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URL: protocol + "://" + service.Spec.ClusterIP + ":" + strconv.Itoa(int(port.Port)),
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Weight: 1,
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}
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} else {
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for _, subset := range endpoints.Subsets {
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for _, address := range subset.Addresses {
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url := protocol + "://" + address.IP + ":" + strconv.Itoa(endpointPortNumber(port, subset.Ports))
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name := url
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if address.TargetRef != nil && address.TargetRef.Name != "" {
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name = address.TargetRef.Name
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}
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templateObjects.Backends[r.Host+pa.Path].Servers[name] = types.Server{
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URL: url,
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Weight: 1,
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}
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}
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}
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}
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}
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break
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}
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}
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}
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}
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}
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return &templateObjects, nil
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}
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func endpointPortNumber(servicePort v1.ServicePort, endpointPorts []v1.EndpointPort) int {
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if len(endpointPorts) > 0 {
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//name is optional if there is only one port
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port := endpointPorts[0]
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for _, endpointPort := range endpointPorts {
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if servicePort.Name == endpointPort.Name {
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port = endpointPort
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}
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}
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return int(port.Port)
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}
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return int(servicePort.Port)
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}
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func equalPorts(servicePort v1.ServicePort, ingressPort intstr.IntOrString) bool {
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if int(servicePort.Port) == ingressPort.IntValue() {
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return true
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}
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if servicePort.Name != "" && servicePort.Name == ingressPort.String() {
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return true
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}
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return false
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}
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func shouldProcessIngress(ingressClass string) bool {
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switch ingressClass {
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case "", "traefik":
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return true
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default:
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return false
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}
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}
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func (provider *Kubernetes) getPassHostHeader() bool {
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if provider.DisablePassHostHeaders {
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return false
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}
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return true
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}
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func (provider *Kubernetes) loadConfig(templateObjects types.Configuration) *types.Configuration {
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var FuncMap = template.FuncMap{}
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configuration, err := provider.getConfiguration("templates/kubernetes.tmpl", FuncMap, templateObjects)
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if err != nil {
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log.Error(err)
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}
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return configuration
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}
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func getRuleTypeFromAnnotation(annotations map[string]string) (ruleType string, unknown bool) {
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ruleType = annotations[annotationFrontendRuleType]
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for _, knownRuleType := range []string{
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ruleTypePathPrefixStrip,
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ruleTypePathStrip,
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ruleTypePath,
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ruleTypePathPrefix,
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} {
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if strings.ToLower(ruleType) == strings.ToLower(knownRuleType) {
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return knownRuleType, false
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}
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}
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if ruleType != "" {
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// Annotation is set but does not match anything we know.
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unknown = true
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}
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return ruleType, unknown
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}
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