ContainerImage.Pinniped/internal/controller/impersonatorconfig/impersonator_config.go

537 lines
16 KiB
Go

// Copyright 2021 the Pinniped contributors. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package impersonatorconfig
import (
"context"
"crypto/tls"
"crypto/x509"
"crypto/x509/pkix"
"encoding/pem"
"errors"
"fmt"
"net"
"net/http"
"sync"
"time"
v1 "k8s.io/api/core/v1"
k8serrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/util/intstr"
corev1informers "k8s.io/client-go/informers/core/v1"
"k8s.io/client-go/kubernetes"
"go.pinniped.dev/internal/certauthority"
"go.pinniped.dev/internal/clusterhost"
"go.pinniped.dev/internal/concierge/impersonator"
pinnipedcontroller "go.pinniped.dev/internal/controller"
"go.pinniped.dev/internal/controllerlib"
"go.pinniped.dev/internal/plog"
)
const (
impersonationProxyPort = ":8444"
)
type impersonatorConfigController struct {
namespace string
configMapResourceName string
k8sClient kubernetes.Interface
configMapsInformer corev1informers.ConfigMapInformer
servicesInformer corev1informers.ServiceInformer
secretsInformer corev1informers.SecretInformer
generatedLoadBalancerServiceName string
tlsSecretName string
labels map[string]string
startTLSListenerFunc StartTLSListenerFunc
httpHandlerFactory func() (http.Handler, error)
server *http.Server
hasControlPlaneNodes *bool
tlsCert *tls.Certificate
tlsCertMutex sync.RWMutex
}
type StartTLSListenerFunc func(network, listenAddress string, config *tls.Config) (net.Listener, error)
func NewImpersonatorConfigController(
namespace string,
configMapResourceName string,
k8sClient kubernetes.Interface,
configMapsInformer corev1informers.ConfigMapInformer,
servicesInformer corev1informers.ServiceInformer,
secretsInformer corev1informers.SecretInformer,
withInformer pinnipedcontroller.WithInformerOptionFunc,
withInitialEvent pinnipedcontroller.WithInitialEventOptionFunc,
generatedLoadBalancerServiceName string,
tlsSecretName string,
labels map[string]string,
startTLSListenerFunc StartTLSListenerFunc,
httpHandlerFactory func() (http.Handler, error),
) controllerlib.Controller {
return controllerlib.New(
controllerlib.Config{
Name: "impersonator-config-controller",
Syncer: &impersonatorConfigController{
namespace: namespace,
configMapResourceName: configMapResourceName,
k8sClient: k8sClient,
configMapsInformer: configMapsInformer,
servicesInformer: servicesInformer,
secretsInformer: secretsInformer,
generatedLoadBalancerServiceName: generatedLoadBalancerServiceName,
tlsSecretName: tlsSecretName,
labels: labels,
startTLSListenerFunc: startTLSListenerFunc,
httpHandlerFactory: httpHandlerFactory,
},
},
withInformer(
configMapsInformer,
pinnipedcontroller.NameAndNamespaceExactMatchFilterFactory(configMapResourceName, namespace),
controllerlib.InformerOption{},
),
withInformer(
servicesInformer,
pinnipedcontroller.NameAndNamespaceExactMatchFilterFactory(generatedLoadBalancerServiceName, namespace),
controllerlib.InformerOption{},
),
withInformer(
secretsInformer,
pinnipedcontroller.NameAndNamespaceExactMatchFilterFactory(tlsSecretName, namespace),
controllerlib.InformerOption{},
),
// Be sure to run once even if the ConfigMap that the informer is watching doesn't exist.
withInitialEvent(controllerlib.Key{
Namespace: namespace,
Name: configMapResourceName,
}),
)
}
func (c *impersonatorConfigController) Sync(ctx controllerlib.Context) error {
plog.Debug("Starting impersonatorConfigController Sync")
configMap, err := c.configMapsInformer.Lister().ConfigMaps(c.namespace).Get(c.configMapResourceName)
notFound := k8serrors.IsNotFound(err)
if err != nil && !notFound {
return fmt.Errorf("failed to get %s/%s configmap: %w", c.namespace, c.configMapResourceName, err)
}
var config *impersonator.Config
if notFound {
plog.Info("Did not find impersonation proxy config: using default config values",
"configmap", c.configMapResourceName,
"namespace", c.namespace,
)
config = impersonator.NewConfig() // use default configuration options
} else {
config, err = impersonator.ConfigFromConfigMap(configMap)
if err != nil {
return fmt.Errorf("invalid impersonator configuration: %v", err)
}
plog.Info("Read impersonation proxy config",
"configmap", c.configMapResourceName,
"namespace", c.namespace,
)
}
// Make a live API call to avoid the cost of having an informer watch all node changes on the cluster,
// since there could be lots and we don't especially care about node changes.
// Once we have concluded that there is or is not a visible control plane, then cache that decision
// to avoid listing nodes very often.
if c.hasControlPlaneNodes == nil {
hasControlPlaneNodes, err := clusterhost.New(c.k8sClient).HasControlPlaneNodes(ctx.Context)
if err != nil {
return err
}
c.hasControlPlaneNodes = &hasControlPlaneNodes
plog.Debug("Queried for control plane nodes", "foundControlPlaneNodes", hasControlPlaneNodes)
}
if c.shouldHaveImpersonator(config) {
if err = c.ensureImpersonatorIsStarted(); err != nil {
return err
}
} else {
if err = c.ensureImpersonatorIsStopped(); err != nil {
return err
}
}
if c.shouldHaveLoadBalancer(config) {
if err = c.ensureLoadBalancerIsStarted(ctx.Context); err != nil {
return err
}
} else {
if err = c.ensureLoadBalancerIsStopped(ctx.Context); err != nil {
return err
}
}
if c.shouldHaveTLSSecret(config) {
err = c.ensureTLSSecret(ctx, config)
if err != nil {
return err
}
} else {
err = c.ensureTLSSecretIsRemoved(ctx.Context)
if err != nil {
return err
}
}
plog.Debug("Successfully finished impersonatorConfigController Sync")
return nil
}
func (c *impersonatorConfigController) ensureTLSSecret(ctx controllerlib.Context, config *impersonator.Config) error {
secret, err := c.secretsInformer.Lister().Secrets(c.namespace).Get(c.tlsSecretName)
notFound := k8serrors.IsNotFound(err)
if notFound {
secret = nil
}
if !notFound && err != nil {
return err
}
//nolint:staticcheck // TODO remove this nolint when we fix the TODO below
if secret, err = c.deleteTLSCertificateWithWrongName(ctx.Context, config, secret); err != nil {
// TODO
// return err
}
if err = c.ensureTLSSecretIsCreatedAndLoaded(ctx.Context, config, secret); err != nil {
return err
}
return nil
}
func (c *impersonatorConfigController) shouldHaveImpersonator(config *impersonator.Config) bool {
return (config.Mode == impersonator.ModeAuto && !*c.hasControlPlaneNodes) || config.Mode == impersonator.ModeEnabled
}
func (c *impersonatorConfigController) shouldHaveLoadBalancer(config *impersonator.Config) bool {
return c.shouldHaveImpersonator(config) && config.Endpoint == ""
}
func (c *impersonatorConfigController) shouldHaveTLSSecret(config *impersonator.Config) bool {
return c.shouldHaveImpersonator(config) // TODO is this the logic that we want here?
}
func (c *impersonatorConfigController) ensureImpersonatorIsStopped() error {
if c.server != nil {
plog.Info("Stopping impersonation proxy", "port", impersonationProxyPort)
err := c.server.Close()
c.server = nil
if err != nil {
return err
}
}
return nil
}
func (c *impersonatorConfigController) ensureImpersonatorIsStarted() error {
if c.server != nil {
return nil
}
handler, err := c.httpHandlerFactory()
if err != nil {
return err
}
listener, err := c.startTLSListenerFunc("tcp", impersonationProxyPort, &tls.Config{
MinVersion: tls.VersionTLS12, // Allow v1.2 because clients like the default `curl` on MacOS don't support 1.3 yet.
GetCertificate: func(info *tls.ClientHelloInfo) (*tls.Certificate, error) {
return c.getTLSCert(), nil
},
})
if err != nil {
return err
}
c.server = &http.Server{Handler: handler}
go func() {
plog.Info("Starting impersonation proxy", "port", impersonationProxyPort)
err = c.server.Serve(listener)
if errors.Is(err, http.ErrServerClosed) {
plog.Info("The impersonation proxy server has shut down")
} else {
plog.Error("Unexpected shutdown of the impersonation proxy server", err)
}
}()
return nil
}
func (c *impersonatorConfigController) isLoadBalancerRunning() (bool, error) {
_, err := c.servicesInformer.Lister().Services(c.namespace).Get(c.generatedLoadBalancerServiceName)
notFound := k8serrors.IsNotFound(err)
if notFound {
return false, nil
}
if err != nil {
return false, err
}
return true, nil
}
func (c *impersonatorConfigController) tlsSecretExists() (bool, *v1.Secret, error) {
secret, err := c.secretsInformer.Lister().Secrets(c.namespace).Get(c.tlsSecretName)
notFound := k8serrors.IsNotFound(err)
if notFound {
return false, nil, nil
}
if err != nil {
return false, nil, err
}
return true, secret, nil
}
func (c *impersonatorConfigController) ensureLoadBalancerIsStarted(ctx context.Context) error {
running, err := c.isLoadBalancerRunning()
if err != nil {
return err
}
if running {
return nil
}
appNameLabel := c.labels["app"]
loadBalancer := v1.Service{
Spec: v1.ServiceSpec{
Type: "LoadBalancer",
Ports: []v1.ServicePort{
{
TargetPort: intstr.FromInt(8444),
Port: 443,
Protocol: v1.ProtocolTCP,
},
},
Selector: map[string]string{"app": appNameLabel},
},
ObjectMeta: metav1.ObjectMeta{
Name: c.generatedLoadBalancerServiceName,
Namespace: c.namespace,
Labels: c.labels,
},
}
plog.Info("creating load balancer for impersonation proxy",
"service", c.generatedLoadBalancerServiceName,
"namespace", c.namespace)
_, err = c.k8sClient.CoreV1().Services(c.namespace).Create(ctx, &loadBalancer, metav1.CreateOptions{})
if err != nil {
return fmt.Errorf("could not create load balancer: %w", err)
}
return nil
}
func (c *impersonatorConfigController) ensureLoadBalancerIsStopped(ctx context.Context) error {
running, err := c.isLoadBalancerRunning()
if err != nil {
return err
}
if !running {
return nil
}
plog.Info("Deleting load balancer for impersonation proxy",
"service", c.generatedLoadBalancerServiceName,
"namespace", c.namespace)
err = c.k8sClient.CoreV1().Services(c.namespace).Delete(ctx, c.generatedLoadBalancerServiceName, metav1.DeleteOptions{})
if err != nil {
return err
}
return nil
}
func (c *impersonatorConfigController) deleteTLSCertificateWithWrongName(ctx context.Context, config *impersonator.Config, secret *v1.Secret) (*v1.Secret, error) {
if secret == nil {
// There is no Secret, so there is nothing to delete.
return secret, nil
}
certPEM := secret.Data[v1.TLSCertKey]
block, _ := pem.Decode(certPEM)
if block == nil {
// The certPEM is not valid.
return secret, nil // TODO what should we do?
}
parsed, _ := x509.ParseCertificate(block.Bytes)
// TODO handle err
desiredIPs, nameIsReady, err := c.findTLSCertificateName(config)
//nolint:staticcheck // TODO remove this nolint when we fix the TODO below
if err != nil {
// TODO return err
}
if !nameIsReady {
// We currently have a secret but we are waiting for a load balancer to be assigned an ingress, so
// our current secret must be old/unwanted.
err = c.ensureTLSSecretIsRemoved(ctx)
if err != nil {
return secret, err
}
return nil, nil
}
actualIPs := parsed.IPAddresses
// TODO handle multiple IPs, and handle when there is no IP
if desiredIPs[0].Equal(actualIPs[0]) {
// The cert matches the desired state, so we do not need to delete it.
return secret, nil
}
err = c.ensureTLSSecretIsRemoved(ctx)
if err != nil {
return secret, err
}
return nil, nil
}
func (c *impersonatorConfigController) ensureTLSSecretIsCreatedAndLoaded(ctx context.Context, config *impersonator.Config, secret *v1.Secret) error {
if secret != nil {
err := c.loadTLSCertFromSecret(secret)
if err != nil {
return err
}
return nil
}
// TODO create/save/watch the CA separately so we can reuse it to mint tls certs as the settings are dynamically changed,
// so that clients don't need to be updated to use a different CA just because the server-side settings were changed.
impersonationCA, err := certauthority.New(pkix.Name{CommonName: "test CA"}, 24*time.Hour) // TODO change the expiration of this to 100 years
if err != nil {
return fmt.Errorf("could not create impersonation CA: %w", err)
}
ips, nameIsReady, err := c.findTLSCertificateName(config)
if err != nil {
return err
}
if !nameIsReady {
// Sync will get called again when the load balancer is updated with its ingress info, so this is not an error.
return nil
}
newTLSSecret, err := c.createNewTLSSecret(ctx, impersonationCA, ips)
if err != nil {
return err
}
err = c.loadTLSCertFromSecret(newTLSSecret)
if err != nil {
return err
}
return nil
}
func (c *impersonatorConfigController) findTLSCertificateName(config *impersonator.Config) ([]net.IP, bool, error) {
var ips []net.IP
if config.Endpoint != "" {
// TODO Endpoint could be a hostname
// TODO Endpoint could have a port number in it, which we should parse out and ignore for this purpose
ips = []net.IP{net.ParseIP(config.Endpoint)}
} else {
lb, err := c.servicesInformer.Lister().Services(c.namespace).Get(c.generatedLoadBalancerServiceName)
notFound := k8serrors.IsNotFound(err)
if notFound {
// TODO is this an error? we should have already created the load balancer, so why would it not exist here?
return nil, false, nil
}
if err != nil {
return nil, false, err
}
ingresses := lb.Status.LoadBalancer.Ingress
if len(ingresses) == 0 {
plog.Info("load balancer for impersonation proxy does not have an ingress yet, so skipping tls cert generation while we wait",
"service", c.generatedLoadBalancerServiceName,
"namespace", c.namespace)
return nil, false, nil
}
ip := ingresses[0].IP // TODO handle multiple ips?
ips = []net.IP{net.ParseIP(ip)}
}
return ips, true, nil
}
func (c *impersonatorConfigController) createNewTLSSecret(ctx context.Context, ca *certauthority.CA, ips []net.IP) (*v1.Secret, error) {
impersonationCert, err := ca.Issue(pkix.Name{}, nil, ips, 24*time.Hour) // TODO change the length of this too 100 years for now?
if err != nil {
return nil, fmt.Errorf("could not create impersonation cert: %w", err)
}
certPEM, keyPEM, _ := certauthority.ToPEM(impersonationCert)
// TODO handle err
newTLSSecret := &v1.Secret{
Type: v1.SecretTypeTLS,
ObjectMeta: metav1.ObjectMeta{
Name: c.tlsSecretName,
Namespace: c.namespace,
Labels: c.labels,
},
Data: map[string][]byte{
"ca.crt": ca.Bundle(),
v1.TLSPrivateKeyKey: keyPEM,
v1.TLSCertKey: certPEM,
},
}
_, _ = c.k8sClient.CoreV1().Secrets(c.namespace).Create(ctx, newTLSSecret, metav1.CreateOptions{})
// TODO handle error on create
return newTLSSecret, nil
}
func (c *impersonatorConfigController) loadTLSCertFromSecret(tlsSecret *v1.Secret) error {
certPEM := tlsSecret.Data[v1.TLSCertKey]
keyPEM := tlsSecret.Data[v1.TLSPrivateKeyKey]
tlsCert, err := tls.X509KeyPair(certPEM, keyPEM)
if err != nil {
plog.Error("Could not parse TLS cert PEM data from Secret",
err,
"secret", c.tlsSecretName,
"namespace", c.namespace,
)
// TODO clear the secret if it was already set previously... c.setTLSCert(nil)
return fmt.Errorf("could not parse TLS cert PEM data from Secret: %w", err)
}
c.setTLSCert(&tlsCert)
return nil
}
func (c *impersonatorConfigController) ensureTLSSecretIsRemoved(ctx context.Context) error {
tlsSecretExists, _, err := c.tlsSecretExists()
if err != nil {
return err
}
if !tlsSecretExists {
return nil
}
plog.Info("Deleting TLS certificates for impersonation proxy",
"service", c.tlsSecretName,
"namespace", c.namespace)
err = c.k8sClient.CoreV1().Secrets(c.namespace).Delete(ctx, c.tlsSecretName, metav1.DeleteOptions{})
if err != nil {
return err
}
c.setTLSCert(nil)
return nil
}
func (c *impersonatorConfigController) setTLSCert(cert *tls.Certificate) {
c.tlsCertMutex.Lock()
defer c.tlsCertMutex.Unlock()
c.tlsCert = cert
}
func (c *impersonatorConfigController) getTLSCert() *tls.Certificate {
c.tlsCertMutex.RLock()
defer c.tlsCertMutex.RUnlock()
return c.tlsCert
}