91ce78da46
Logging errors into a file inside a minimalistic container might not be possible, and glog bails out with an exit code > 0 if it fails.
393 lines
12 KiB
Go
393 lines
12 KiB
Go
package kubernetes
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import (
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"bufio"
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"bytes"
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"errors"
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"flag"
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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"
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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/pkg/api/v1"
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"k8s.io/client-go/pkg/apis/extensions/v1beta1"
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"k8s.io/client-go/pkg/util/intstr"
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)
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var _ provider.Provider = (*Provider)(nil)
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const (
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annotationFrontendRuleType = "traefik.frontend.rule.type"
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ruleTypePathPrefix = "PathPrefix"
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)
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const traefikDefaultRealm = "traefik"
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// Provider holds configurations of the provider.
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type Provider struct {
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provider.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 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 (p *Provider) newK8sClient() (Client, error) {
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withEndpoint := ""
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if p.Endpoint != "" {
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withEndpoint = fmt.Sprintf(" with endpoint %v", p.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 Provider client%s\n", withEndpoint)
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return NewInClusterClient(p.Endpoint)
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}
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log.Infof("Creating cluster-external Provider client%s\n", withEndpoint)
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return NewExternalClusterClient(p.Endpoint, p.Token, p.CertAuthFilePath)
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}
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// Provide allows the k8s provider to provide configurations to traefik
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// using the given configuration channel.
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func (p *Provider) Provide(configurationChan chan<- types.ConfigMessage, pool *safe.Pool, constraints types.Constraints) error {
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// Tell glog (used by client-go) to log into STDERR. Otherwise, we risk
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// certain kinds of API errors getting logged into a directory not
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// available in a `FROM scratch` Docker container, causing glog to abort
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// hard with an exit code > 0.
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flag.Set("logtostderr", "true")
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k8sClient, err := p.newK8sClient()
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if err != nil {
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return err
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}
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p.Constraints = append(p.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'", p.LabelSelector)
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eventsChan, err := k8sClient.WatchAll(p.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 := p.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(p.lastConfiguration.Get(), templateObjects) {
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log.Debugf("Skipping event from kubernetes %+v", event)
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} else {
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p.lastConfiguration.Set(templateObjects)
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configurationChan <- types.ConfigMessage{
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ProviderName: "kubernetes",
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Configuration: p.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("Provider connection error: %s; 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 Provider: %s", err)
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}
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})
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return nil
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}
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func (p *Provider) loadIngresses(k8sClient Client) (*types.Configuration, error) {
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ingresses := k8sClient.GetIngresses(p.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 := p.getPassHostHeader()
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passHostHeaderAnnotation, ok := i.Annotations["traefik.frontend.passHostHeader"]
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switch {
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case !ok:
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// No op.
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case passHostHeaderAnnotation == "false":
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PassHostHeader = false
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case passHostHeaderAnnotation == "true":
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PassHostHeader = true
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default:
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log.Warnf("Unknown value '%s' for traefik.frontend.passHostHeader, falling back to %s", passHostHeaderAnnotation, PassHostHeader)
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}
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if realm := i.Annotations["ingress.kubernetes.io/auth-realm"]; realm != "" && realm != traefikDefaultRealm {
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return nil, errors.New("no realm customization supported")
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}
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if _, exists := templateObjects.Frontends[r.Host+pa.Path]; !exists {
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basicAuthCreds, err := handleBasicAuthConfig(i, k8sClient)
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if err != nil {
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log.Errorf("Failed to retrieve basic auth configuration for ingress %s/%s: %s", i.ObjectMeta.Namespace, i.ObjectMeta.Name, err)
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continue
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}
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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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BasicAuth: basicAuthCreds,
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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 := i.Annotations[annotationFrontendRuleType]
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if 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 {
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log.Errorf("Error while retrieving service information from k8s API %s/%s: %v", i.ObjectMeta.Namespace, pa.Backend.ServiceName, err)
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return nil, err
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}
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if !exists {
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log.Errorf("Service not found for %s/%s", i.ObjectMeta.Namespace, pa.Backend.ServiceName)
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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 retrieving endpoints %s/%s: %v", service.ObjectMeta.Namespace, service.ObjectMeta.Name, err)
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return nil, err
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}
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if !exists {
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log.Warnf("Endpoints not found for %s/%s", service.ObjectMeta.Namespace, service.ObjectMeta.Name)
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break
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}
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if len(endpoints.Subsets) == 0 {
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log.Warnf("Endpoints not available for %s/%s", service.ObjectMeta.Namespace, service.ObjectMeta.Name)
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break
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}
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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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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 handleBasicAuthConfig(i *v1beta1.Ingress, k8sClient Client) ([]string, error) {
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authType, exists := i.Annotations["ingress.kubernetes.io/auth-type"]
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if !exists {
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return nil, nil
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}
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if strings.ToLower(authType) != "basic" {
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return nil, fmt.Errorf("unsupported auth-type on annotation ingress.kubernetes.io/auth-type: %q", authType)
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}
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authSecret := i.Annotations["ingress.kubernetes.io/auth-secret"]
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if authSecret == "" {
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return nil, errors.New("auth-secret annotation ingress.kubernetes.io/auth-secret must be set")
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}
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basicAuthCreds, err := loadAuthCredentials(i.Namespace, authSecret, k8sClient)
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if err != nil {
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return nil, fmt.Errorf("failed to load auth credentials: %s", err)
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}
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return basicAuthCreds, nil
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}
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func loadAuthCredentials(namespace, secretName string, k8sClient Client) ([]string, error) {
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secret, ok, err := k8sClient.GetSecret(namespace, secretName)
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switch { // keep order of case conditions
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case err != nil:
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return nil, fmt.Errorf("failed to fetch secret %q/%q: %s", namespace, secretName, err)
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case !ok:
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return nil, fmt.Errorf("secret %q/%q not found", namespace, secretName)
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case secret == nil:
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return nil, fmt.Errorf("data for secret %q/%q must not be nil", namespace, secretName)
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case len(secret.Data) != 1:
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return nil, fmt.Errorf("found %d elements for secret %q/%q, must be single element exactly", len(secret.Data), namespace, secretName)
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default:
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}
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var firstSecret []byte
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for _, v := range secret.Data {
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firstSecret = v
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break
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}
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creds := make([]string, 0)
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scanner := bufio.NewScanner(bytes.NewReader(firstSecret))
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for scanner.Scan() {
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if cred := scanner.Text(); cred != "" {
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creds = append(creds, cred)
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}
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}
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if len(creds) == 0 {
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return nil, fmt.Errorf("secret %q/%q does not contain any credentials", namespace, secretName)
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}
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return creds, 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 (p *Provider) getPassHostHeader() bool {
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if p.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 (p *Provider) loadConfig(templateObjects types.Configuration) *types.Configuration {
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var FuncMap = template.FuncMap{}
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configuration, err := p.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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