package crd import ( "context" "crypto/sha256" "flag" "fmt" "os" "reflect" "sort" "strconv" "strings" "time" "github.com/cenkalti/backoff" "github.com/containous/traefik/config" "github.com/containous/traefik/job" "github.com/containous/traefik/log" "github.com/containous/traefik/provider" "github.com/containous/traefik/provider/kubernetes/crd/traefik/v1alpha1" "github.com/containous/traefik/provider/kubernetes/k8s" "github.com/containous/traefik/safe" "github.com/containous/traefik/tls" "github.com/pkg/errors" corev1 "k8s.io/api/core/v1" "k8s.io/apimachinery/pkg/labels" ) const ( annotationKubernetesIngressClass = "kubernetes.io/ingress.class" traefikDefaultIngressClass = "traefik" ) // IngressEndpoint holds the endpoint information for the Kubernetes provider. type IngressEndpoint struct { IP string `description:"IP used for Kubernetes Ingress endpoints"` Hostname string `description:"Hostname used for Kubernetes Ingress endpoints"` PublishedService string `description:"Published Kubernetes Service to copy status from"` } // Provider holds configurations of the provider. type Provider struct { provider.BaseProvider `mapstructure:",squash" export:"true"` Endpoint string `description:"Kubernetes server endpoint (required for external cluster client)"` Token string `description:"Kubernetes bearer token (not needed for in-cluster client)"` CertAuthFilePath string `description:"Kubernetes certificate authority file path (not needed for in-cluster client)"` DisablePassHostHeaders bool `description:"Kubernetes disable PassHost Headers" export:"true"` EnablePassTLSCert bool `description:"Kubernetes enable Pass TLS Client Certs" export:"true"` // Deprecated Namespaces k8s.Namespaces `description:"Kubernetes namespaces" export:"true"` LabelSelector string `description:"Kubernetes Ingress label selector to use" export:"true"` IngressClass string `description:"Value of kubernetes.io/ingress.class annotation to watch for" export:"true"` IngressEndpoint *IngressEndpoint `description:"Kubernetes Ingress Endpoint"` lastConfiguration safe.Safe } func (p *Provider) newK8sClient(ctx context.Context, ingressLabelSelector string) (*clientWrapper, error) { ingLabelSel, err := labels.Parse(ingressLabelSelector) if err != nil { return nil, fmt.Errorf("invalid ingress label selector: %q", ingressLabelSelector) } log.FromContext(ctx).Infof("ingress label selector is: %q", ingLabelSel) withEndpoint := "" if p.Endpoint != "" { withEndpoint = fmt.Sprintf(" with endpoint %v", p.Endpoint) } var client *clientWrapper switch { case os.Getenv("KUBERNETES_SERVICE_HOST") != "" && os.Getenv("KUBERNETES_SERVICE_PORT") != "": log.FromContext(ctx).Infof("Creating in-cluster Provider client%s", withEndpoint) client, err = newInClusterClient(p.Endpoint) case os.Getenv("KUBECONFIG") != "": log.FromContext(ctx).Infof("Creating cluster-external Provider client from KUBECONFIG %s", os.Getenv("KUBECONFIG")) client, err = newExternalClusterClientFromFile(os.Getenv("KUBECONFIG")) default: log.FromContext(ctx).Infof("Creating cluster-external Provider client%s", withEndpoint) client, err = newExternalClusterClient(p.Endpoint, p.Token, p.CertAuthFilePath) } if err == nil { client.ingressLabelSelector = ingLabelSel } return client, err } // Init the provider. func (p *Provider) Init() error { return p.BaseProvider.Init() } // Provide allows the k8s provider to provide configurations to traefik // using the given configuration channel. func (p *Provider) Provide(configurationChan chan<- config.Message, pool *safe.Pool) error { ctxLog := log.With(context.Background(), log.Str(log.ProviderName, "kubernetescrd")) logger := log.FromContext(ctxLog) // Tell glog (used by client-go) to log into STDERR. Otherwise, we risk // certain kinds of API errors getting logged into a directory not // available in a `FROM scratch` Docker container, causing glog to abort // hard with an exit code > 0. err := flag.Set("logtostderr", "true") if err != nil { return err } logger.Debugf("Using Ingress label selector: %q", p.LabelSelector) k8sClient, err := p.newK8sClient(ctxLog, p.LabelSelector) if err != nil { return err } pool.Go(func(stop chan bool) { operation := func() error { stopWatch := make(chan struct{}, 1) defer close(stopWatch) eventsChan, err := k8sClient.WatchAll(p.Namespaces, stopWatch) if err != nil { logger.Errorf("Error watching kubernetes events: %v", err) timer := time.NewTimer(1 * time.Second) select { case <-timer.C: return err case <-stop: return nil } } for { select { case <-stop: return nil case event := <-eventsChan: conf := p.loadConfigurationFromIngresses(ctxLog, k8sClient) if reflect.DeepEqual(p.lastConfiguration.Get(), conf) { logger.Debugf("Skipping Kubernetes event kind %T", event) } else { p.lastConfiguration.Set(conf) configurationChan <- config.Message{ ProviderName: "kubernetescrd", Configuration: conf, } } } } } notify := func(err error, time time.Duration) { logger.Errorf("Provider connection error: %s; retrying in %s", err, time) } err := backoff.RetryNotify(safe.OperationWithRecover(operation), job.NewBackOff(backoff.NewExponentialBackOff()), notify) if err != nil { logger.Errorf("Cannot connect to Provider: %s", err) } }) return nil } func checkStringQuoteValidity(value string) error { _, err := strconv.Unquote(`"` + value + `"`) return err } func loadServers(client Client, namespace string, svc v1alpha1.Service) ([]config.Server, error) { strategy := svc.Strategy if strategy == "" { strategy = "RoundRobin" } if strategy != "RoundRobin" { return nil, fmt.Errorf("load balancing strategy %v is not supported", strategy) } service, exists, err := client.GetService(namespace, svc.Name) if err != nil { return nil, err } if !exists { return nil, errors.New("service not found") } var portSpec corev1.ServicePort var match bool // TODO: support name ports? do we actually care? for _, p := range service.Spec.Ports { if svc.Port == p.Port { portSpec = p match = true break } } if !match { return nil, errors.New("service port not found") } var servers []config.Server if service.Spec.Type == corev1.ServiceTypeExternalName { servers = append(servers, config.Server{ URL: fmt.Sprintf("http://%s:%d", service.Spec.ExternalName, portSpec.Port), Weight: 1, }) } else { endpoints, endpointsExists, endpointsErr := client.GetEndpoints(namespace, svc.Name) if endpointsErr != nil { return nil, endpointsErr } if !endpointsExists { return nil, errors.New("endpoints not found") } if len(endpoints.Subsets) == 0 { return nil, errors.New("subset not found") } var port int32 for _, subset := range endpoints.Subsets { for _, p := range subset.Ports { if portSpec.Name == p.Name { port = p.Port break } } if port == 0 { return nil, errors.New("cannot define a port") } protocol := "http" if port == 443 || strings.HasPrefix(portSpec.Name, "https") { protocol = "https" } for _, addr := range subset.Addresses { servers = append(servers, config.Server{ URL: fmt.Sprintf("%s://%s:%d", protocol, addr.IP, port), Weight: 1, }) } } } return servers, nil } func (p *Provider) loadConfigurationFromIngresses(ctx context.Context, client Client) *config.Configuration { conf := &config.Configuration{ HTTP: &config.HTTPConfiguration{ Routers: map[string]*config.Router{}, Middlewares: map[string]*config.Middleware{}, Services: map[string]*config.Service{}, }, TCP: &config.TCPConfiguration{}, } tlsConfigs := make(map[string]*tls.Configuration) for _, ingressRoute := range client.GetIngressRoutes() { logger := log.FromContext(log.With(ctx, log.Str("ingress", ingressRoute.Name), log.Str("namespace", ingressRoute.Namespace))) // TODO keep the name ingressClass? if !shouldProcessIngress(p.IngressClass, ingressRoute.Annotations[annotationKubernetesIngressClass]) { continue } err := getTLS(ctx, ingressRoute, client, tlsConfigs) if err != nil { logger.Errorf("Error configuring TLS: %v", err) } ingressName := ingressRoute.Name if len(ingressName) == 0 { ingressName = ingressRoute.GenerateName } for _, route := range ingressRoute.Spec.Routes { if route.Kind != "Rule" { logger.Errorf("Unsupported match kind: %s. Only \"Rule\" is supported for now.", route.Kind) continue } if len(route.Match) == 0 { logger.Errorf("Empty match rule") continue } if err := checkStringQuoteValidity(route.Match); err != nil { logger.Errorf("Invalid syntax for match rule: %s", route.Match) continue } var allServers []config.Server for _, service := range route.Services { servers, err := loadServers(client, ingressRoute.Namespace, service) if err != nil { logger. WithField("serviceName", service.Name). WithField("servicePort", service.Port). Errorf("Cannot create service: %v", err) continue } allServers = append(allServers, servers...) } // TODO: support middlewares from other providers. // Mechanism: in the spec, prefix the name with the provider name, // with dot as the separator. In which case. we ignore the // namespace. var mds []string for _, mi := range route.Middlewares { ns := mi.Namespace if len(ns) == 0 { ns = ingressRoute.Namespace } mds = append(mds, makeID(ns, mi.Name)) } h := sha256.New() _, err = h.Write([]byte(route.Match)) if err != nil { logger.Error(err) continue } key := fmt.Sprintf("%s-%.10x", ingressName, h.Sum(nil)) serviceName := makeID(ingressRoute.Namespace, key) conf.HTTP.Routers[serviceName] = &config.Router{ Middlewares: mds, Priority: route.Priority, EntryPoints: ingressRoute.Spec.EntryPoints, Rule: route.Match, Service: serviceName, } if ingressRoute.Spec.TLS != nil { conf.HTTP.Routers[serviceName].TLS = &config.RouterTLSConfig{} } conf.HTTP.Services[serviceName] = &config.Service{ LoadBalancer: &config.LoadBalancerService{ Servers: allServers, // TODO: support other strategies. Method: "wrr", PassHostHeader: true, }, } } } conf.TLS = getTLSConfig(tlsConfigs) for _, middleware := range client.GetMiddlewares() { conf.HTTP.Middlewares[makeID(middleware.Namespace, middleware.Name)] = &middleware.Spec } return conf } func makeID(namespace, name string) string { if namespace == "" { return name } return namespace + "/" + name } func shouldProcessIngress(ingressClass string, ingressClassAnnotation string) bool { return ingressClass == ingressClassAnnotation || (len(ingressClass) == 0 && ingressClassAnnotation == traefikDefaultIngressClass) } func getTLS(ctx context.Context, ingressRoute *v1alpha1.IngressRoute, k8sClient Client, tlsConfigs map[string]*tls.Configuration) error { if ingressRoute.Spec.TLS == nil { return nil } if ingressRoute.Spec.TLS.SecretName == "" { log.FromContext(ctx).Debugf("Skipping TLS sub-section: No secret name provided") return nil } configKey := ingressRoute.Namespace + "/" + ingressRoute.Spec.TLS.SecretName if _, tlsExists := tlsConfigs[configKey]; !tlsExists { secret, exists, err := k8sClient.GetSecret(ingressRoute.Namespace, ingressRoute.Spec.TLS.SecretName) if err != nil { return fmt.Errorf("failed to fetch secret %s/%s: %v", ingressRoute.Namespace, ingressRoute.Spec.TLS.SecretName, err) } if !exists { return fmt.Errorf("secret %s/%s does not exist", ingressRoute.Namespace, ingressRoute.Spec.TLS.SecretName) } cert, key, err := getCertificateBlocks(secret, ingressRoute.Namespace, ingressRoute.Spec.TLS.SecretName) if err != nil { return err } tlsConfigs[configKey] = &tls.Configuration{ Certificate: &tls.Certificate{ CertFile: tls.FileOrContent(cert), KeyFile: tls.FileOrContent(key), }, } } return nil } func getTLSConfig(tlsConfigs map[string]*tls.Configuration) []*tls.Configuration { var secretNames []string for secretName := range tlsConfigs { secretNames = append(secretNames, secretName) } sort.Strings(secretNames) var configs []*tls.Configuration for _, secretName := range secretNames { configs = append(configs, tlsConfigs[secretName]) } return configs } func getCertificateBlocks(secret *corev1.Secret, namespace, secretName string) (string, string, error) { var missingEntries []string tlsCrtData, tlsCrtExists := secret.Data["tls.crt"] if !tlsCrtExists { missingEntries = append(missingEntries, "tls.crt") } tlsKeyData, tlsKeyExists := secret.Data["tls.key"] if !tlsKeyExists { missingEntries = append(missingEntries, "tls.key") } if len(missingEntries) > 0 { return "", "", fmt.Errorf("secret %s/%s is missing the following TLS data entries: %s", namespace, secretName, strings.Join(missingEntries, ", ")) } cert := string(tlsCrtData) if cert == "" { missingEntries = append(missingEntries, "tls.crt") } key := string(tlsKeyData) if key == "" { missingEntries = append(missingEntries, "tls.key") } if len(missingEntries) > 0 { return "", "", fmt.Errorf("secret %s/%s contains the following empty TLS data entries: %s", namespace, secretName, strings.Join(missingEntries, ", ")) } return cert, key, nil }