traefik/pkg/provider/kubernetes/crd/kubernetes.go
2019-07-12 17:50:04 +02:00

747 lines
22 KiB
Go

package crd
import (
"context"
"crypto/sha256"
"errors"
"flag"
"fmt"
"os"
"reflect"
"sort"
"strconv"
"strings"
"time"
"github.com/cenkalti/backoff"
"github.com/containous/traefik/pkg/config/dynamic"
"github.com/containous/traefik/pkg/job"
"github.com/containous/traefik/pkg/log"
"github.com/containous/traefik/pkg/provider/kubernetes/crd/traefik/v1alpha1"
"github.com/containous/traefik/pkg/safe"
"github.com/containous/traefik/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)
// 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 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 checkStringQuoteValidity(value string) error {
_, err := strconv.Unquote(`"` + value + `"`)
return err
}
func loadTCPServers(client Client, namespace string, svc v1alpha1.ServiceTCP) ([]dynamic.TCPServer, error) {
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
for _, p := range service.Spec.Ports {
if svc.Port == p.Port {
portSpec = &p
break
}
}
if portSpec == nil {
return nil, errors.New("service port not found")
}
var servers []dynamic.TCPServer
if service.Spec.Type == corev1.ServiceTypeExternalName {
servers = append(servers, dynamic.TCPServer{
Address: fmt.Sprintf("%s:%d", service.Spec.ExternalName, portSpec.Port),
})
} 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")
}
for _, addr := range subset.Addresses {
servers = append(servers, dynamic.TCPServer{
Address: fmt.Sprintf("%s:%d", addr.IP, port),
})
}
}
}
return servers, nil
}
func loadServers(client Client, namespace string, svc v1alpha1.Service) ([]dynamic.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
for _, p := range service.Spec.Ports {
if svc.Port == p.Port {
portSpec = &p
break
}
}
if portSpec == nil {
return nil, errors.New("service port not found")
}
var servers []dynamic.Server
if service.Spec.Type == corev1.ServiceTypeExternalName {
servers = append(servers, dynamic.Server{
URL: fmt.Sprintf("http://%s:%d", service.Spec.ExternalName, portSpec.Port),
})
} 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"
switch svc.Scheme {
case "http", "https", "h2c":
protocol = svc.Scheme
case "":
if port == 443 || strings.HasPrefix(portSpec.Name, "https") {
protocol = "https"
}
default:
return nil, fmt.Errorf("invalid scheme %q specified", svc.Scheme)
}
for _, addr := range subset.Addresses {
servers = append(servers, dynamic.Server{
URL: fmt.Sprintf("%s://%s:%d", protocol, addr.IP, port),
})
}
}
}
return servers, nil
}
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 (p *Provider) loadIngressRouteConfiguration(ctx context.Context, client Client, tlsConfigs map[string]*tls.CertAndStores) *dynamic.HTTPConfiguration {
conf := &dynamic.HTTPConfiguration{
Routers: map[string]*dynamic.Router{},
Middlewares: map[string]*dynamic.Middleware{},
Services: map[string]*dynamic.Service{},
}
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 := getTLSHTTP(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 []dynamic.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...)
}
var mds []string
for _, mi := range route.Middlewares {
if strings.Contains(mi.Name, "@") {
if len(mi.Namespace) > 0 {
logger.
WithField(log.MiddlewareName, mi.Name).
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 = ingressRoute.Namespace
}
mds = append(mds, makeID(ns, mi.Name))
}
key, err := makeServiceKey(route.Match, ingressName)
if err != nil {
logger.Error(err)
continue
}
serviceName := makeID(ingressRoute.Namespace, key)
conf.Routers[serviceName] = &dynamic.Router{
Middlewares: mds,
Priority: route.Priority,
EntryPoints: ingressRoute.Spec.EntryPoints,
Rule: route.Match,
Service: serviceName,
}
if ingressRoute.Spec.TLS != nil {
tlsConf := &dynamic.RouterTLSConfig{}
if ingressRoute.Spec.TLS.Options != nil && len(ingressRoute.Spec.TLS.Options.Name) > 0 {
tlsOptionsName := ingressRoute.Spec.TLS.Options.Name
// Is a Kubernetes CRD reference, (i.e. not a cross-provider reference)
ns := ingressRoute.Spec.TLS.Options.Namespace
if !strings.Contains(tlsOptionsName, "@") {
if len(ns) == 0 {
ns = ingressRoute.Namespace
}
tlsOptionsName = makeID(ns, tlsOptionsName)
} else if len(ns) > 0 {
logger.
WithField("TLSoptions", ingressRoute.Spec.TLS.Options.Name).
Warnf("namespace %q is ignored in cross-provider context", ns)
}
tlsConf.Options = tlsOptionsName
}
conf.Routers[serviceName].TLS = tlsConf
}
conf.Services[serviceName] = &dynamic.Service{
LoadBalancer: &dynamic.LoadBalancerService{
Servers: allServers,
// TODO: support other strategies.
PassHostHeader: true,
},
}
}
}
return conf
}
func (p *Provider) loadIngressRouteTCPConfiguration(ctx context.Context, client Client, tlsConfigs map[string]*tls.CertAndStores) *dynamic.TCPConfiguration {
conf := &dynamic.TCPConfiguration{
Routers: map[string]*dynamic.TCPRouter{},
Services: map[string]*dynamic.TCPService{},
}
for _, ingressRouteTCP := range client.GetIngressRouteTCPs() {
logger := log.FromContext(log.With(ctx, log.Str("ingress", ingressRouteTCP.Name), log.Str("namespace", ingressRouteTCP.Namespace)))
if !shouldProcessIngress(p.IngressClass, ingressRouteTCP.Annotations[annotationKubernetesIngressClass]) {
continue
}
if ingressRouteTCP.Spec.TLS != nil && !ingressRouteTCP.Spec.TLS.Passthrough {
err := getTLSTCP(ctx, ingressRouteTCP, client, tlsConfigs)
if err != nil {
logger.Errorf("Error configuring TLS: %v", err)
}
}
ingressName := ingressRouteTCP.Name
if len(ingressName) == 0 {
ingressName = ingressRouteTCP.GenerateName
}
for _, route := range ingressRouteTCP.Spec.Routes {
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 []dynamic.TCPServer
for _, service := range route.Services {
servers, err := loadTCPServers(client, ingressRouteTCP.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...)
}
key, e := makeServiceKey(route.Match, ingressName)
if e != nil {
logger.Error(e)
continue
}
serviceName := makeID(ingressRouteTCP.Namespace, key)
conf.Routers[serviceName] = &dynamic.TCPRouter{
EntryPoints: ingressRouteTCP.Spec.EntryPoints,
Rule: route.Match,
Service: serviceName,
}
if ingressRouteTCP.Spec.TLS != nil {
conf.Routers[serviceName].TLS = &dynamic.RouterTCPTLSConfig{
Passthrough: ingressRouteTCP.Spec.TLS.Passthrough,
}
if ingressRouteTCP.Spec.TLS.Options != nil && len(ingressRouteTCP.Spec.TLS.Options.Name) > 0 {
tlsOptionsName := ingressRouteTCP.Spec.TLS.Options.Name
// Is a Kubernetes CRD reference (i.e. not a cross-provider reference)
ns := ingressRouteTCP.Spec.TLS.Options.Namespace
if !strings.Contains(tlsOptionsName, "@") {
if len(ns) == 0 {
ns = ingressRouteTCP.Namespace
}
tlsOptionsName = makeID(ns, tlsOptionsName)
} else if len(ns) > 0 {
logger.
WithField("TLSoptions", ingressRouteTCP.Spec.TLS.Options.Name).
Warnf("namespace %q is ignored in cross-provider context", ns)
}
conf.Routers[serviceName].TLS.Options = tlsOptionsName
}
}
conf.Services[serviceName] = &dynamic.TCPService{
LoadBalancer: &dynamic.TCPLoadBalancerService{
Servers: allServers,
},
}
}
}
return conf
}
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 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 getTLSHTTP(ctx context.Context, ingressRoute *v1alpha1.IngressRoute, k8sClient Client, tlsConfigs map[string]*tls.CertAndStores) 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 {
tlsConf, err := getTLS(k8sClient, ingressRoute.Spec.TLS.SecretName, ingressRoute.Namespace)
if err != nil {
return err
}
tlsConfigs[configKey] = tlsConf
}
return nil
}
func getTLSTCP(ctx context.Context, ingressRoute *v1alpha1.IngressRouteTCP, k8sClient Client, tlsConfigs map[string]*tls.CertAndStores) error {
if ingressRoute.Spec.TLS == nil {
return nil
}
if ingressRoute.Spec.TLS.SecretName == "" {
log.FromContext(ctx).Debugf("Skipping TLS sub-section for TCP: No secret name provided")
return nil
}
configKey := ingressRoute.Namespace + "/" + ingressRoute.Spec.TLS.SecretName
if _, tlsExists := tlsConfigs[configKey]; !tlsExists {
tlsConf, err := getTLS(k8sClient, ingressRoute.Spec.TLS.SecretName, ingressRoute.Namespace)
if err != nil {
return err
}
tlsConfigs[configKey] = tlsConf
}
return nil
}
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
}