add dynamic reloading for CSR signing controllers

This commit is contained in:
David Eads 2020-01-03 12:26:56 -05:00
parent a06d16565c
commit 6ccfc3aecf
6 changed files with 157 additions and 47 deletions

View File

@ -74,6 +74,7 @@
"k8s.io/apimachinery/pkg/version",
"k8s.io/api/imagepolicy/v1alpha1",
"k8s.io/apiserver/pkg/admission",
"k8s.io/apiserver/pkg/server/dynamiccertificates",
"k8s.io/apiserver/pkg/storage",
"k8s.io/api/batch/v2alpha1",
"k8s.io/apiserver/pkg/registry/rest",

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@ -30,6 +30,11 @@ var serialNumberLimit = new(big.Int).Lsh(big.NewInt(1), 128)
// CertificateAuthority implements a certificate authority that supports policy
// based signing. It's used by the signing controller.
type CertificateAuthority struct {
// RawCert is an optional field to determine if signing cert/key pairs have changed
RawCert []byte
// RawKey is an optional field to determine if signing cert/key pairs have changed
RawKey []byte
Certificate *x509.Certificate
PrivateKey crypto.Signer
Backdate time.Duration

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@ -26,13 +26,17 @@ go_test(
go_library(
name = "go_default_library",
srcs = ["signer.go"],
srcs = [
"ca_provider.go",
"signer.go",
],
importpath = "k8s.io/kubernetes/pkg/controller/certificates/signer",
deps = [
"//pkg/apis/certificates/v1beta1:go_default_library",
"//pkg/controller/certificates:go_default_library",
"//pkg/controller/certificates/authority:go_default_library",
"//staging/src/k8s.io/api/certificates/v1beta1:go_default_library",
"//staging/src/k8s.io/apiserver/pkg/server/dynamiccertificates:go_default_library",
"//staging/src/k8s.io/client-go/informers/certificates/v1beta1:go_default_library",
"//staging/src/k8s.io/client-go/kubernetes:go_default_library",
"//staging/src/k8s.io/client-go/util/cert:go_default_library",

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@ -0,0 +1,101 @@
/*
Copyright 2020 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package signer
import (
"bytes"
"crypto"
"fmt"
"sync/atomic"
"time"
"k8s.io/apiserver/pkg/server/dynamiccertificates"
"k8s.io/client-go/util/cert"
"k8s.io/client-go/util/keyutil"
"k8s.io/kubernetes/pkg/controller/certificates/authority"
)
func newCAProvider(caFile, caKeyFile string) (*caProvider, error) {
caLoader, err := dynamiccertificates.NewDynamicServingContentFromFiles("csr-controller", caFile, caKeyFile)
if err != nil {
return nil, fmt.Errorf("error reading CA cert file %q: %v", caFile, err)
}
ret := &caProvider{
caLoader: caLoader,
}
if err := ret.setCA(); err != nil {
return nil, err
}
return ret, nil
}
type caProvider struct {
caValue atomic.Value
caLoader *dynamiccertificates.DynamicFileServingContent
}
// setCA unconditionally stores the current cert/key content
func (p *caProvider) setCA() error {
certPEM, keyPEM := p.caLoader.CurrentCertKeyContent()
certs, err := cert.ParseCertsPEM(certPEM)
if err != nil {
return fmt.Errorf("error reading CA cert file %q: %v", p.caLoader.Name(), err)
}
if len(certs) != 1 {
return fmt.Errorf("error reading CA cert file %q: expected 1 certificate, found %d", p.caLoader.Name(), len(certs))
}
key, err := keyutil.ParsePrivateKeyPEM(keyPEM)
if err != nil {
return fmt.Errorf("error reading CA key file %q: %v", p.caLoader.Name(), err)
}
priv, ok := key.(crypto.Signer)
if !ok {
return fmt.Errorf("error reading CA key file %q: key did not implement crypto.Signer", p.caLoader.Name())
}
ca := &authority.CertificateAuthority{
RawCert: certPEM,
RawKey: keyPEM,
Certificate: certs[0],
PrivateKey: priv,
Backdate: 5 * time.Minute,
}
p.caValue.Store(ca)
return nil
}
// currentCA provides the curent value of the CA.
// It always check for a stale value. This is cheap because it's all an in memory cache of small slices.
func (p *caProvider) currentCA() (*authority.CertificateAuthority, error) {
certPEM, keyPEM := p.caLoader.CurrentCertKeyContent()
currCA := p.caValue.Load().(*authority.CertificateAuthority)
if bytes.Equal(currCA.RawCert, certPEM) && bytes.Equal(currCA.RawKey, keyPEM) {
return currCA, nil
}
// the bytes weren't equal, so we have to set and then load
if err := p.setCA(); err != nil {
return currCA, err
}
return p.caValue.Load().(*authority.CertificateAuthority), nil
}

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@ -18,82 +18,72 @@ limitations under the License.
package signer
import (
"crypto"
"encoding/pem"
"fmt"
"io/ioutil"
"time"
capi "k8s.io/api/certificates/v1beta1"
"k8s.io/apiserver/pkg/server/dynamiccertificates"
certificatesinformers "k8s.io/client-go/informers/certificates/v1beta1"
clientset "k8s.io/client-go/kubernetes"
"k8s.io/client-go/util/cert"
"k8s.io/client-go/util/keyutil"
capihelper "k8s.io/kubernetes/pkg/apis/certificates/v1beta1"
"k8s.io/kubernetes/pkg/controller/certificates"
"k8s.io/kubernetes/pkg/controller/certificates/authority"
)
type CSRSigningController struct {
certificateController *certificates.CertificateController
dynamicCertReloader dynamiccertificates.ControllerRunner
}
func NewCSRSigningController(
client clientset.Interface,
csrInformer certificatesinformers.CertificateSigningRequestInformer,
caFile, caKeyFile string,
certTTL time.Duration,
) (*certificates.CertificateController, error) {
) (*CSRSigningController, error) {
signer, err := newSigner(caFile, caKeyFile, client, certTTL)
if err != nil {
return nil, err
}
return certificates.NewCertificateController(
"csrsigning",
client,
csrInformer,
signer.handle,
), nil
return &CSRSigningController{
certificateController: certificates.NewCertificateController(
"csrsigning",
client,
csrInformer,
signer.handle,
),
dynamicCertReloader: signer.caProvider.caLoader,
}, nil
}
// Run the main goroutine responsible for watching and syncing jobs.
func (c *CSRSigningController) Run(workers int, stopCh <-chan struct{}) {
go c.dynamicCertReloader.Run(workers, stopCh)
c.certificateController.Run(workers, stopCh)
}
type signer struct {
ca *authority.CertificateAuthority
caProvider *caProvider
client clientset.Interface
certTTL time.Duration
}
func newSigner(caFile, caKeyFile string, client clientset.Interface, certificateDuration time.Duration) (*signer, error) {
certPEM, err := ioutil.ReadFile(caFile)
caProvider, err := newCAProvider(caFile, caKeyFile)
if err != nil {
return nil, fmt.Errorf("error reading CA cert file %q: %v", caFile, err)
return nil, err
}
certs, err := cert.ParseCertsPEM(certPEM)
if err != nil {
return nil, fmt.Errorf("error reading CA cert file %q: %v", caFile, err)
ret := &signer{
caProvider: caProvider,
client: client,
certTTL: certificateDuration,
}
if len(certs) != 1 {
return nil, fmt.Errorf("error reading CA cert file %q: expected 1 certificate, found %d", caFile, len(certs))
}
keyPEM, err := ioutil.ReadFile(caKeyFile)
if err != nil {
return nil, fmt.Errorf("error reading CA key file %q: %v", caKeyFile, err)
}
key, err := keyutil.ParsePrivateKeyPEM(keyPEM)
if err != nil {
return nil, fmt.Errorf("error reading CA key file %q: %v", caKeyFile, err)
}
priv, ok := key.(crypto.Signer)
if !ok {
return nil, fmt.Errorf("error reading CA key file %q: key did not implement crypto.Signer", caKeyFile)
}
return &signer{
ca: &authority.CertificateAuthority{
Certificate: certs[0],
PrivateKey: priv,
Backdate: 5 * time.Minute,
},
client: client,
certTTL: certificateDuration,
}, nil
return ret, nil
}
func (s *signer) handle(csr *capi.CertificateSigningRequest) error {
@ -117,7 +107,11 @@ func (s *signer) sign(csr *capi.CertificateSigningRequest) (*capi.CertificateSig
return nil, fmt.Errorf("unable to parse csr %q: %v", csr.Name, err)
}
der, err := s.ca.Sign(x509cr.Raw, authority.PermissiveSigningPolicy{
currCA, err := s.caProvider.currentCA()
if err != nil {
return nil, err
}
der, err := currCA.Sign(x509cr.Raw, authority.PermissiveSigningPolicy{
TTL: s.certTTL,
Usages: csr.Spec.Usages,
})

View File

@ -38,8 +38,13 @@ func TestSigner(t *testing.T) {
if err != nil {
t.Fatalf("failed to create signer: %v", err)
}
s.ca.Now = clock.Now
s.ca.Backdate = 0
currCA, err := s.caProvider.currentCA()
if err != nil {
t.Fatal(err)
}
currCA.Now = clock.Now
currCA.Backdate = 0
s.caProvider.caValue.Store(currCA)
csrb, err := ioutil.ReadFile("./testdata/kubelet.csr")
if err != nil {