package crd import ( "context" "crypto/sha256" "fmt" "os" "reflect" "sort" "strconv" "strings" "time" "github.com/cenkalti/backoff/v3" "github.com/containous/traefik/v2/pkg/config/dynamic" "github.com/containous/traefik/v2/pkg/job" "github.com/containous/traefik/v2/pkg/log" "github.com/containous/traefik/v2/pkg/safe" "github.com/containous/traefik/v2/pkg/tls" corev1 "k8s.io/api/core/v1" "k8s.io/apimachinery/pkg/labels" ) const ( annotationKubernetesIngressClass = "kubernetes.io/ingress.class" traefikDefaultIngressClass = "traefik" ) // Provider holds configurations of the provider. type Provider struct { Endpoint string `description:"Kubernetes server endpoint (required for external cluster client)." json:"endpoint,omitempty" toml:"endpoint,omitempty" yaml:"endpoint,omitempty"` Token string `description:"Kubernetes bearer token (not needed for in-cluster client)." json:"token,omitempty" toml:"token,omitempty" yaml:"token,omitempty"` CertAuthFilePath string `description:"Kubernetes certificate authority file path (not needed for in-cluster client)." json:"certAuthFilePath,omitempty" toml:"certAuthFilePath,omitempty" yaml:"certAuthFilePath,omitempty"` DisablePassHostHeaders bool `description:"Kubernetes disable PassHost Headers." json:"disablePassHostHeaders,omitempty" toml:"disablePassHostHeaders,omitempty" yaml:"disablePassHostHeaders,omitempty" export:"true"` Namespaces []string `description:"Kubernetes namespaces." json:"namespaces,omitempty" toml:"namespaces,omitempty" yaml:"namespaces,omitempty" export:"true"` LabelSelector string `description:"Kubernetes label selector to use." json:"labelSelector,omitempty" toml:"labelSelector,omitempty" yaml:"labelSelector,omitempty" export:"true"` IngressClass string `description:"Value of kubernetes.io/ingress.class annotation to watch for." json:"ingressClass,omitempty" toml:"ingressClass,omitempty" yaml:"ingressClass,omitempty" export:"true"` lastConfiguration safe.Safe } func (p *Provider) newK8sClient(ctx context.Context, labelSelector string) (*clientWrapper, error) { labelSel, err := labels.Parse(labelSelector) if err != nil { return nil, fmt.Errorf("invalid label selector: %q", labelSelector) } log.FromContext(ctx).Infof("label selector is: %q", labelSel) 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.labelSelector = labelSel } return client, err } // Init the provider. func (p *Provider) Init() error { return nil } // Provide allows the k8s provider to provide configurations to traefik // using the given configuration channel. func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.Pool) error { ctxLog := log.With(context.Background(), log.Str(log.ProviderName, "kubernetescrd")) logger := log.FromContext(ctxLog) logger.Debugf("Using 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.loadConfigurationFromCRD(ctxLog, k8sClient) if reflect.DeepEqual(p.lastConfiguration.Get(), conf) { logger.Debugf("Skipping Kubernetes event kind %T", event) } else { p.lastConfiguration.Set(conf) configurationChan <- dynamic.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 (p *Provider) loadConfigurationFromCRD(ctx context.Context, client Client) *dynamic.Configuration { tlsConfigs := make(map[string]*tls.CertAndStores) conf := &dynamic.Configuration{ HTTP: p.loadIngressRouteConfiguration(ctx, client, tlsConfigs), TCP: p.loadIngressRouteTCPConfiguration(ctx, client, tlsConfigs), TLS: &dynamic.TLSConfiguration{ Certificates: getTLSConfig(tlsConfigs), Options: buildTLSOptions(ctx, client), }, } for _, middleware := range client.GetMiddlewares() { conf.HTTP.Middlewares[makeID(middleware.Namespace, middleware.Name)] = &middleware.Spec } return conf } func buildTLSOptions(ctx context.Context, client Client) map[string]tls.Options { tlsOptionsCRD := client.GetTLSOptions() var tlsOptions map[string]tls.Options if len(tlsOptionsCRD) == 0 { return tlsOptions } tlsOptions = make(map[string]tls.Options) for _, tlsOption := range tlsOptionsCRD { logger := log.FromContext(log.With(ctx, log.Str("tlsOption", tlsOption.Name), log.Str("namespace", tlsOption.Namespace))) var clientCAs []tls.FileOrContent for _, secretName := range tlsOption.Spec.ClientAuth.SecretNames { secret, exists, err := client.GetSecret(tlsOption.Namespace, secretName) if err != nil { logger.Errorf("Failed to fetch secret %s/%s: %v", tlsOption.Namespace, secretName, err) continue } if !exists { logger.Warnf("Secret %s/%s does not exist", tlsOption.Namespace, secretName) continue } cert, err := getCABlocks(secret, tlsOption.Namespace, secretName) if err != nil { logger.Errorf("Failed to extract CA from secret %s/%s: %v", tlsOption.Namespace, secretName, err) continue } clientCAs = append(clientCAs, tls.FileOrContent(cert)) } tlsOptions[makeID(tlsOption.Namespace, tlsOption.Name)] = tls.Options{ MinVersion: tlsOption.Spec.MinVersion, CipherSuites: tlsOption.Spec.CipherSuites, ClientAuth: tls.ClientAuth{ CAFiles: clientCAs, ClientAuthType: tlsOption.Spec.ClientAuth.ClientAuthType, }, SniStrict: tlsOption.Spec.SniStrict, } } return tlsOptions } func checkStringQuoteValidity(value string) error { _, err := strconv.Unquote(`"` + value + `"`) return err } func makeServiceKey(rule, ingressName string) (string, error) { h := sha256.New() if _, err := h.Write([]byte(rule)); err != nil { return "", err } key := fmt.Sprintf("%s-%.10x", ingressName, h.Sum(nil)) return key, nil } 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(k8sClient Client, secretName, namespace string) (*tls.CertAndStores, error) { secret, exists, err := k8sClient.GetSecret(namespace, secretName) if err != nil { return nil, fmt.Errorf("failed to fetch secret %s/%s: %v", namespace, secretName, err) } if !exists { return nil, fmt.Errorf("secret %s/%s does not exist", namespace, secretName) } cert, key, err := getCertificateBlocks(secret, namespace, secretName) if err != nil { return nil, err } return &tls.CertAndStores{ Certificate: tls.Certificate{ CertFile: tls.FileOrContent(cert), KeyFile: tls.FileOrContent(key), }, }, nil } func getTLSConfig(tlsConfigs map[string]*tls.CertAndStores) []*tls.CertAndStores { var secretNames []string for secretName := range tlsConfigs { secretNames = append(secretNames, secretName) } sort.Strings(secretNames) var configs []*tls.CertAndStores 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 } func getCABlocks(secret *corev1.Secret, namespace, secretName string) (string, error) { tlsCrtData, tlsCrtExists := secret.Data["tls.ca"] if !tlsCrtExists { return "", fmt.Errorf("the tls.ca entry is missing from secret %s/%s", namespace, secretName) } cert := string(tlsCrtData) if cert == "" { return "", fmt.Errorf("the tls.ca entry in secret %s/%s is empty", namespace, secretName) } return cert, nil }