traefik/pkg/provider/kubernetes/crd/kubernetes.go

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package crd
import (
"bufio"
"bytes"
"context"
"crypto/sha256"
"fmt"
"os"
"sort"
"strconv"
"strings"
"time"
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"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/provider/kubernetes/crd/traefik/v1alpha1"
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"github.com/containous/traefik/v2/pkg/safe"
"github.com/containous/traefik/v2/pkg/tls"
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"github.com/containous/traefik/v2/pkg/types"
"github.com/mitchellh/hashstructure"
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 {
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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"`
ThrottleDuration types.Duration `description:"Ingress refresh throttle duration" json:"throttleDuration,omitempty" toml:"throttleDuration,omitempty" yaml:"throttleDuration,omitempty"`
lastConfiguration safe.Safe
}
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func (p *Provider) newK8sClient(ctx context.Context, labelSelector string) (*clientWrapper, error) {
labelSel, err := labels.Parse(labelSelector)
if err != nil {
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return nil, fmt.Errorf("invalid label selector: %q", labelSelector)
}
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log.FromContext(ctx).Infof("label selector is: %q", labelSel)
withEndpoint := ""
if p.Endpoint != "" {
withEndpoint = fmt.Sprintf(" with endpoint %v", p.Endpoint)
}
var client *clientWrapper
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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)
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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"))
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default:
log.FromContext(ctx).Infof("Creating cluster-external Provider client%s", withEndpoint)
client, err = newExternalClusterClient(p.Endpoint, p.Token, p.CertAuthFilePath)
}
if err == nil {
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client.labelSelector = labelSel
}
return client, err
}
// Init the provider.
func (p *Provider) Init() error {
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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)
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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)
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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
}
}
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throttleDuration := time.Duration(p.ThrottleDuration)
throttledChan := throttleEvents(ctxLog, throttleDuration, stop, eventsChan)
if throttledChan != nil {
eventsChan = throttledChan
}
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for {
select {
case <-stop:
return nil
case event := <-eventsChan:
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// Note that event is the *first* event that came in during this
// throttling interval -- if we're hitting our throttle, we may have
// dropped events. This is fine, because we don't treat different
// event types differently. But if we do in the future, we'll need to
// track more information about the dropped events.
conf := p.loadConfigurationFromCRD(ctxLog, k8sClient)
confHash, err := hashstructure.Hash(conf, nil)
switch {
case err != nil:
logger.Error("Unable to hash the configuration")
case p.lastConfiguration.Get() == confHash:
logger.Debugf("Skipping Kubernetes event kind %T", event)
default:
p.lastConfiguration.Set(confHash)
configurationChan <- dynamic.Message{
ProviderName: "kubernetescrd",
Configuration: conf,
}
}
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// If we're throttling, we sleep here for the throttle duration to
// enforce that we don't refresh faster than our throttle. time.Sleep
// returns immediately if p.ThrottleDuration is 0 (no throttle).
time.Sleep(throttleDuration)
}
}
}
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() {
id := makeID(middleware.Namespace, middleware.Name)
ctxMid := log.With(ctx, log.Str(log.MiddlewareName, id))
basicAuth, err := createBasicAuthMiddleware(client, middleware.Namespace, middleware.Spec.BasicAuth)
if err != nil {
log.FromContext(ctxMid).Errorf("Error while reading basic auth middleware: %v", err)
continue
}
digestAuth, err := createDigestAuthMiddleware(client, middleware.Namespace, middleware.Spec.DigestAuth)
if err != nil {
log.FromContext(ctxMid).Errorf("Error while reading digest auth middleware: %v", err)
continue
}
forwardAuth, err := createForwardAuthMiddleware(client, middleware.Namespace, middleware.Spec.ForwardAuth)
if err != nil {
log.FromContext(ctxMid).Errorf("Error while reading forward auth middleware: %v", err)
continue
}
errorPage, errorPageService, err := createErrorPageMiddleware(client, middleware.Namespace, middleware.Spec.Errors)
if err != nil {
log.FromContext(ctxMid).Errorf("Error while reading error page middleware: %v", err)
continue
}
if errorPage != nil && errorPageService != nil {
serviceName := id + "-errorpage-service"
errorPage.Service = serviceName
conf.HTTP.Services[serviceName] = errorPageService
}
conf.HTTP.Middlewares[id] = &dynamic.Middleware{
AddPrefix: middleware.Spec.AddPrefix,
StripPrefix: middleware.Spec.StripPrefix,
StripPrefixRegex: middleware.Spec.StripPrefixRegex,
ReplacePath: middleware.Spec.ReplacePath,
ReplacePathRegex: middleware.Spec.ReplacePathRegex,
Chain: createChainMiddleware(ctxMid, middleware.Namespace, middleware.Spec.Chain),
IPWhiteList: middleware.Spec.IPWhiteList,
Headers: middleware.Spec.Headers,
Errors: errorPage,
RateLimit: middleware.Spec.RateLimit,
RedirectRegex: middleware.Spec.RedirectRegex,
RedirectScheme: middleware.Spec.RedirectScheme,
BasicAuth: basicAuth,
DigestAuth: digestAuth,
ForwardAuth: forwardAuth,
InFlightReq: middleware.Spec.InFlightReq,
Buffering: middleware.Spec.Buffering,
CircuitBreaker: middleware.Spec.CircuitBreaker,
Compress: middleware.Spec.Compress,
PassTLSClientCert: middleware.Spec.PassTLSClientCert,
Retry: middleware.Spec.Retry,
}
}
return conf
}
func createErrorPageMiddleware(client Client, namespace string, errorPage *v1alpha1.ErrorPage) (*dynamic.ErrorPage, *dynamic.Service, error) {
if errorPage == nil {
return nil, nil, nil
}
errorPageMiddleware := &dynamic.ErrorPage{
Status: errorPage.Status,
Query: errorPage.Query,
}
balancerServerHTTP, err := createLoadBalancerServerHTTP(client, namespace, errorPage.Service)
if err != nil {
return nil, nil, err
}
return errorPageMiddleware, balancerServerHTTP, nil
}
func createForwardAuthMiddleware(k8sClient Client, namespace string, auth *v1alpha1.ForwardAuth) (*dynamic.ForwardAuth, error) {
if auth == nil {
return nil, nil
}
if len(auth.Address) == 0 {
return nil, fmt.Errorf("forward authentication requires an address")
}
forwardAuth := &dynamic.ForwardAuth{
Address: auth.Address,
TrustForwardHeader: auth.TrustForwardHeader,
AuthResponseHeaders: auth.AuthResponseHeaders,
}
if auth.TLS == nil {
return forwardAuth, nil
}
forwardAuth.TLS = &dynamic.ClientTLS{
CAOptional: auth.TLS.CAOptional,
InsecureSkipVerify: auth.TLS.InsecureSkipVerify,
}
if len(auth.TLS.CASecret) > 0 {
caSecret, err := loadCASecret(namespace, auth.TLS.CASecret, k8sClient)
if err != nil {
return nil, fmt.Errorf("failed to load auth ca secret: %v", err)
}
forwardAuth.TLS.CA = caSecret
}
if len(auth.TLS.CertSecret) > 0 {
authSecretCert, authSecretKey, err := loadAuthTLSSecret(namespace, auth.TLS.CertSecret, k8sClient)
if err != nil {
return nil, fmt.Errorf("failed to load auth secret: %s", err)
}
forwardAuth.TLS.Cert = authSecretCert
forwardAuth.TLS.Key = authSecretKey
}
return forwardAuth, nil
}
func loadCASecret(namespace, secretName string, k8sClient Client) (string, error) {
secret, ok, err := k8sClient.GetSecret(namespace, secretName)
if err != nil {
return "", fmt.Errorf("failed to fetch secret '%s/%s': %s", namespace, secretName, err)
}
if !ok {
return "", fmt.Errorf("secret '%s/%s' not found", namespace, secretName)
}
if secret == nil {
return "", fmt.Errorf("data for secret '%s/%s' must not be nil", namespace, secretName)
}
if len(secret.Data) != 1 {
return "", fmt.Errorf("found %d elements for secret '%s/%s', must be single element exactly", len(secret.Data), namespace, secretName)
}
for _, v := range secret.Data {
return string(v), nil
}
return "", nil
}
func loadAuthTLSSecret(namespace, secretName string, k8sClient Client) (string, string, error) {
secret, exists, err := k8sClient.GetSecret(namespace, secretName)
if err != nil {
return "", "", fmt.Errorf("failed to fetch secret '%s/%s': %s", namespace, secretName, err)
}
if !exists {
return "", "", fmt.Errorf("secret '%s/%s' does not exist", namespace, secretName)
}
if secret == nil {
return "", "", fmt.Errorf("data for secret '%s/%s' must not be nil", namespace, secretName)
}
if len(secret.Data) != 2 {
return "", "", fmt.Errorf("found %d elements for secret '%s/%s', must be two elements exactly", len(secret.Data), namespace, secretName)
}
return getCertificateBlocks(secret, namespace, secretName)
}
func createBasicAuthMiddleware(client Client, namespace string, basicAuth *v1alpha1.BasicAuth) (*dynamic.BasicAuth, error) {
if basicAuth == nil {
return nil, nil
}
credentials, err := getAuthCredentials(client, basicAuth.Secret, namespace)
if err != nil {
return nil, err
}
return &dynamic.BasicAuth{
Users: credentials,
Realm: basicAuth.Realm,
RemoveHeader: basicAuth.RemoveHeader,
HeaderField: basicAuth.HeaderField,
}, nil
}
func createDigestAuthMiddleware(client Client, namespace string, digestAuth *v1alpha1.DigestAuth) (*dynamic.DigestAuth, error) {
if digestAuth == nil {
return nil, nil
}
credentials, err := getAuthCredentials(client, digestAuth.Secret, namespace)
if err != nil {
return nil, err
}
return &dynamic.DigestAuth{
Users: credentials,
Realm: digestAuth.Realm,
RemoveHeader: digestAuth.RemoveHeader,
HeaderField: digestAuth.HeaderField,
}, nil
}
func getAuthCredentials(k8sClient Client, authSecret, namespace string) ([]string, error) {
if authSecret == "" {
return nil, fmt.Errorf("auth secret must be set")
}
auth, err := loadAuthCredentials(namespace, authSecret, k8sClient)
if err != nil {
return nil, fmt.Errorf("failed to load auth credentials: %s", err)
}
return auth, nil
}
func loadAuthCredentials(namespace, secretName string, k8sClient Client) ([]string, error) {
secret, ok, err := k8sClient.GetSecret(namespace, secretName)
if err != nil {
return nil, fmt.Errorf("failed to fetch secret '%s/%s': %s", namespace, secretName, err)
}
if !ok {
return nil, fmt.Errorf("secret '%s/%s' not found", namespace, secretName)
}
if secret == nil {
return nil, fmt.Errorf("data for secret '%s/%s' must not be nil", namespace, secretName)
}
if len(secret.Data) != 1 {
return nil, fmt.Errorf("found %d elements for secret '%s/%s', must be single element exactly", len(secret.Data), namespace, secretName)
}
var firstSecret []byte
for _, v := range secret.Data {
firstSecret = v
break
}
var credentials []string
scanner := bufio.NewScanner(bytes.NewReader(firstSecret))
for scanner.Scan() {
if cred := scanner.Text(); len(cred) > 0 {
credentials = append(credentials, cred)
}
}
if err := scanner.Err(); err != nil {
return nil, fmt.Errorf("error reading secret for %v/%v: %v", namespace, secretName, err)
}
if len(credentials) == 0 {
return nil, fmt.Errorf("secret '%s/%s' does not contain any credentials", namespace, secretName)
}
return credentials, nil
}
func createChainMiddleware(ctx context.Context, namespace string, chain *v1alpha1.Chain) *dynamic.Chain {
if chain == nil {
return nil
}
var mds []string
for _, mi := range chain.Middlewares {
if strings.Contains(mi.Name, "@") {
if len(mi.Namespace) > 0 {
log.FromContext(ctx).
Warnf("namespace %q is ignored in cross-provider context", mi.Namespace)
}
mds = append(mds, mi.Name)
continue
}
ns := mi.Namespace
if len(ns) == 0 {
ns = namespace
}
mds = append(mds, makeID(ns, mi.Name))
}
return &dynamic.Chain{Middlewares: mds}
}
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
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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,
MaxVersion: tlsOption.Spec.MaxVersion,
CipherSuites: tlsOption.Spec.CipherSuites,
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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
}
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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
}
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func throttleEvents(ctx context.Context, throttleDuration time.Duration, stop chan bool, eventsChan <-chan interface{}) chan interface{} {
if throttleDuration == 0 {
return nil
}
// Create a buffered channel to hold the pending event (if we're delaying processing the event due to throttling)
eventsChanBuffered := make(chan interface{}, 1)
// Run a goroutine that reads events from eventChan and does a
// non-blocking write to pendingEvent. This guarantees that writing to
// eventChan will never block, and that pendingEvent will have
// something in it if there's been an event since we read from that channel.
go func() {
for {
select {
case <-stop:
return
case nextEvent := <-eventsChan:
select {
case eventsChanBuffered <- nextEvent:
default:
// We already have an event in eventsChanBuffered, so we'll
// do a refresh as soon as our throttle allows us to. It's fine
// to drop the event and keep whatever's in the buffer -- we
// don't do different things for different events
log.FromContext(ctx).Debugf("Dropping event kind %T due to throttling", nextEvent)
}
}
}
}()
return eventsChanBuffered
}