ContainerImage.Pinniped/internal/controller/apicerts/certs_manager.go

134 lines
4.3 KiB
Go

/*
Copyright 2020 VMware, Inc.
SPDX-License-Identifier: Apache-2.0
*/
package apicerts
import (
"crypto/x509/pkix"
"fmt"
"time"
corev1 "k8s.io/api/core/v1"
k8serrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
corev1informers "k8s.io/client-go/informers/core/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/klog/v2"
"github.com/suzerain-io/pinniped/internal/certauthority"
pinnipedcontroller "github.com/suzerain-io/pinniped/internal/controller"
"github.com/suzerain-io/pinniped/internal/controllerlib"
)
const (
//nolint: gosec
certsSecretName = "api-serving-cert"
caCertificateSecretKey = "caCertificate"
tlsPrivateKeySecretKey = "tlsPrivateKey"
tlsCertificateChainSecretKey = "tlsCertificateChain"
)
type certsManagerController struct {
namespace string
k8sClient kubernetes.Interface
secretInformer corev1informers.SecretInformer
// certDuration is the lifetime of both the serving certificate and its CA
// certificate that this controller will use when issuing the certificates.
certDuration time.Duration
generatedCACommonName string
serviceNameForGeneratedCertCommonName string
}
func NewCertsManagerController(namespace string,
k8sClient kubernetes.Interface,
secretInformer corev1informers.SecretInformer,
withInformer pinnipedcontroller.WithInformerOptionFunc,
withInitialEvent pinnipedcontroller.WithInitialEventOptionFunc,
certDuration time.Duration,
generatedCACommonName string,
serviceNameForGeneratedCertCommonName string,
) controllerlib.Controller {
return controllerlib.New(
controllerlib.Config{
Name: "certs-manager-controller",
Syncer: &certsManagerController{
namespace: namespace,
k8sClient: k8sClient,
secretInformer: secretInformer,
certDuration: certDuration,
generatedCACommonName: generatedCACommonName,
serviceNameForGeneratedCertCommonName: serviceNameForGeneratedCertCommonName,
},
},
withInformer(
secretInformer,
pinnipedcontroller.NameAndNamespaceExactMatchFilterFactory(certsSecretName, namespace),
controllerlib.InformerOption{},
),
// Be sure to run once even if the Secret that the informer is watching doesn't exist.
withInitialEvent(controllerlib.Key{
Namespace: namespace,
Name: certsSecretName,
}),
)
}
func (c *certsManagerController) Sync(ctx controllerlib.Context) error {
// Try to get the secret from the informer cache.
_, err := c.secretInformer.Lister().Secrets(c.namespace).Get(certsSecretName)
notFound := k8serrors.IsNotFound(err)
if err != nil && !notFound {
return fmt.Errorf("failed to get %s/%s secret: %w", c.namespace, certsSecretName, err)
}
if !notFound {
// The secret already exists, so nothing to do.
return nil
}
// Create a CA.
aggregatedAPIServerCA, err := certauthority.New(pkix.Name{CommonName: c.generatedCACommonName}, c.certDuration)
if err != nil {
return fmt.Errorf("could not initialize CA: %w", err)
}
// Using the CA from above, create a TLS server cert for the aggregated API server to use.
serviceEndpoint := c.serviceNameForGeneratedCertCommonName + "." + c.namespace + ".svc"
aggregatedAPIServerTLSCert, err := aggregatedAPIServerCA.Issue(
pkix.Name{CommonName: serviceEndpoint},
[]string{serviceEndpoint},
c.certDuration,
)
if err != nil {
return fmt.Errorf("could not issue serving certificate: %w", err)
}
// Write the CA's public key bundle and the serving certs to a secret.
tlsCertChainPEM, tlsPrivateKeyPEM, err := certauthority.ToPEM(aggregatedAPIServerTLSCert)
if err != nil {
return fmt.Errorf("could not PEM encode serving certificate: %w", err)
}
secret := corev1.Secret{
TypeMeta: metav1.TypeMeta{},
ObjectMeta: metav1.ObjectMeta{
Name: certsSecretName,
Namespace: c.namespace,
},
StringData: map[string]string{
caCertificateSecretKey: string(aggregatedAPIServerCA.Bundle()),
tlsPrivateKeySecretKey: string(tlsPrivateKeyPEM),
tlsCertificateChainSecretKey: string(tlsCertChainPEM),
},
}
_, err = c.k8sClient.CoreV1().Secrets(c.namespace).Create(ctx.Context, &secret, metav1.CreateOptions{})
if err != nil {
return fmt.Errorf("could not create secret: %w", err)
}
klog.Info("certsManagerController Sync successfully created secret")
return nil
}