images/kube-webhook-certgen/rootfs: improvements (#7630)

* images/kube-webhook-certgen/rootfs/README.md: remove trailing whitespace

Signed-off-by: Mateusz Gozdek <mgozdek@microsoft.com>

* images/kube-webhook-certgen/rootfs: improve code formatting

Automatically using gofumpt.

Signed-off-by: Mateusz Gozdek <mgozdek@microsoft.com>

* images/kube-webhook-certgen/rootfs: remove executable bits from files

Signed-off-by: Mateusz Gozdek <mgozdek@microsoft.com>

* images/kube-webhook-certgen/rootfs/cmd: remove unreachable code

log.Fatal(|f) will alread call os.Exit(1), so this code is never
reached.

Signed-off-by: Mateusz Gozdek <mgozdek@microsoft.com>

* images/kube-webhook-certgen/rootfs/pkg/k8s: fix unit tests

Right now they fail as everything else migrated from using v1beta1 to
v1.

Signed-off-by: Mateusz Gozdek <mgozdek@microsoft.com>

* images/kube-webhook-certgen/rootfs: create clientset in cmd package

So one can easily mock the client, without touching unexported parts of
the code and to soften the dependency between CLI code (kubeconfig
path).

Signed-off-by: Mateusz Gozdek <mgozdek@microsoft.com>

* images/kube-webhook-certgen/rootfs/cmd: simplify bool logic

Signed-off-by: Mateusz Gozdek <mgozdek@microsoft.com>

* images/kube-webhook-certgen/rootfs/pkg/k8s: improve formatting

Signed-off-by: Mateusz Gozdek <mgozdek@microsoft.com>

* images/kube-webhook-certgen/rootfs/pkg/k8s: improve variable names

Signed-off-by: Mateusz Gozdek <mgozdek@microsoft.com>

* images/kube-webhook-certgen/rootfs/pkg/k8s: refactor a bit

Move patching logic to separate functions.

Signed-off-by: Mateusz Gozdek <mgozdek@microsoft.com>

* images/kube-webhook-certgen/rootfs/pkg/k8s: fix error log messages

In patchMutating() function, log messages were waying still patching
validating webhook.

Signed-off-by: Mateusz Gozdek <mgozdek@microsoft.com>
This commit is contained in:
Mateusz Gozdek 2021-09-16 22:59:26 +02:00 committed by GitHub
parent b3389a1b6f
commit 260910c0a0
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
8 changed files with 108 additions and 94 deletions

0
images/kube-webhook-certgen/rootfs/README.md Executable file → Normal file
View file

9
images/kube-webhook-certgen/rootfs/cmd/create.go Executable file → Normal file
View file

@ -7,17 +7,16 @@ import (
"github.com/spf13/cobra"
)
var (
create = &cobra.Command{
var create = &cobra.Command{
Use: "create",
Short: "Generate a ca and server cert+key and store the results in a secret 'secret-name' in 'namespace'",
Long: "Generate a ca and server cert+key and store the results in a secret 'secret-name' in 'namespace'",
PreRun: configureLogging,
Run: createCommand}
)
Run: createCommand,
}
func createCommand(cmd *cobra.Command, args []string) {
k := k8s.New(cfg.kubeconfig)
k := k8s.New(newKubernetesClient(cfg.kubeconfig))
ca := k.GetCaFromSecret(cfg.secretName, cfg.namespace)
if ca == nil {
log.Info("creating new secret")

15
images/kube-webhook-certgen/rootfs/cmd/patch.go Executable file → Normal file
View file

@ -1,28 +1,24 @@
package cmd
import (
"os"
"github.com/jet/kube-webhook-certgen/pkg/k8s"
log "github.com/sirupsen/logrus"
"github.com/spf13/cobra"
admissionv1 "k8s.io/api/admissionregistration/v1"
)
var (
patch = &cobra.Command{
var patch = &cobra.Command{
Use: "patch",
Short: "Patch a validatingwebhookconfiguration and mutatingwebhookconfiguration 'webhook-name' by using the ca from 'secret-name' in 'namespace'",
Long: "Patch a validatingwebhookconfiguration and mutatingwebhookconfiguration 'webhook-name' by using the ca from 'secret-name' in 'namespace'",
PreRun: prePatchCommand,
Run: patchCommand}
)
Run: patchCommand,
}
func prePatchCommand(cmd *cobra.Command, args []string) {
configureLogging(cmd, args)
if cfg.patchMutating == false && cfg.patchValidating == false {
if !cfg.patchMutating && !cfg.patchValidating {
log.Fatal("patch-validating=false, patch-mutating=false. You must patch at least one kind of webhook, otherwise this command is a no-op")
os.Exit(1)
}
switch cfg.patchFailurePolicy {
case "":
@ -33,12 +29,11 @@ func prePatchCommand(cmd *cobra.Command, args []string) {
break
default:
log.Fatalf("patch-failure-policy %s is not valid", cfg.patchFailurePolicy)
os.Exit(1)
}
}
func patchCommand(_ *cobra.Command, _ []string) {
k := k8s.New(cfg.kubeconfig)
k := k8s.New(newKubernetesClient(cfg.kubeconfig))
ca := k.GetCaFromSecret(cfg.secretName, cfg.namespace)
if ca == nil {

16
images/kube-webhook-certgen/rootfs/cmd/root.go Executable file → Normal file
View file

@ -7,6 +7,8 @@ import (
log "github.com/sirupsen/logrus"
"github.com/spf13/cobra"
admissionv1 "k8s.io/api/admissionregistration/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/clientcmd"
)
var (
@ -81,3 +83,17 @@ func getFormatter(logfmt string) log.Formatter {
log.Fatalf("invalid log format '%s'", logfmt)
return nil
}
func newKubernetesClient(kubeconfig string) kubernetes.Interface {
config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
if err != nil {
log.WithError(err).Fatal("error building kubernetes config")
}
c, err := kubernetes.NewForConfig(config)
if err != nil {
log.WithError(err).Fatal("error creating kubernetes client")
}
return c
}

View file

@ -7,11 +7,12 @@ import (
"crypto/x509"
"crypto/x509/pkix"
"encoding/pem"
log "github.com/sirupsen/logrus"
"math/big"
"net"
"strings"
"time"
log "github.com/sirupsen/logrus"
)
// GenerateCerts venerates a ca with a leaf certificate and key and returns the ca, cert and key as PEM encoded slices

View file

@ -16,7 +16,6 @@ func handler(w http.ResponseWriter, r *http.Request) {
}
func TestCertificateCreation(t *testing.T) {
ca, cert, key := GenerateCerts("localhost")
c, err := tls.X509KeyPair(cert, key)
@ -30,7 +29,9 @@ func TestCertificateCreation(t *testing.T) {
tr := &http.Transport{
TLSClientConfig: &tls.Config{
RootCAs: caCertPool,
ServerName: "localhost"}}
ServerName: "localhost",
},
}
ts := httptest.NewUnstartedServer(http.HandlerFunc(handler))
ts.TLS = &tls.Config{Certificates: []tls.Certificate{c}}

61
images/kube-webhook-certgen/rootfs/pkg/k8s/k8s.go Executable file → Normal file
View file

@ -9,42 +9,53 @@ import (
k8serrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/clientcmd"
)
type k8s struct {
clientset kubernetes.Interface
}
func New(kubeconfig string) *k8s {
config, err := clientcmd.BuildConfigFromFlags("", kubeconfig)
if err != nil {
log.WithError(err).Fatal("error building kubernetes config")
func New(clientset kubernetes.Interface) *k8s {
if clientset == nil {
log.Fatal("no kubernetes client given")
}
c, err := kubernetes.NewForConfig(config)
if err != nil {
log.WithError(err).Fatal("error creating kubernetes client")
return &k8s{
clientset: clientset,
}
return &k8s{clientset: c}
}
// PatchWebhookConfigurations will patch validatingWebhook and mutatingWebhook clientConfig configurations with
// the provided ca data. If failurePolicy is provided, patch all webhooks with this value
func (k8s *k8s) PatchWebhookConfigurations(
configurationNames string, ca []byte,
configurationName string,
ca []byte,
failurePolicy *admissionv1.FailurePolicyType,
patchMutating bool, patchValidating bool) {
log.Infof("patching webhook configurations '%s' mutating=%t, validating=%t, failurePolicy=%s", configurationNames, patchMutating, patchValidating, *failurePolicy)
patchMutating bool,
patchValidating bool,
) {
log.Infof("patching webhook configurations '%s' mutating=%t, validating=%t, failurePolicy=%s", configurationName, patchMutating, patchValidating, *failurePolicy)
if patchValidating {
k8s.patchValidating(configurationName, ca, failurePolicy)
} else {
log.Debug("validating hook patching not required")
}
if patchMutating {
k8s.patchMutating(configurationName, ca, failurePolicy)
} else {
log.Debug("mutating hook patching not required")
}
log.Info("Patched hook(s)")
}
func (k8s *k8s) patchValidating(configurationName string, ca []byte, failurePolicy *admissionv1.FailurePolicyType) {
valHook, err := k8s.clientset.
AdmissionregistrationV1().
ValidatingWebhookConfigurations().
Get(context.TODO(), configurationNames, metav1.GetOptions{})
Get(context.TODO(), configurationName, metav1.GetOptions{})
if err != nil {
log.WithField("err", err).Fatal("failed getting validating webhook")
}
@ -63,17 +74,15 @@ func (k8s *k8s) PatchWebhookConfigurations(
log.WithField("err", err).Fatal("failed patching validating webhook")
}
log.Debug("patched validating hook")
} else {
log.Debug("validating hook patching not required")
}
}
if patchMutating {
func (k8s *k8s) patchMutating(configurationName string, ca []byte, failurePolicy *admissionv1.FailurePolicyType) {
mutHook, err := k8s.clientset.
AdmissionregistrationV1().
MutatingWebhookConfigurations().
Get(context.TODO(), configurationNames, metav1.GetOptions{})
Get(context.TODO(), configurationName, metav1.GetOptions{})
if err != nil {
log.WithField("err", err).Fatal("failed getting validating webhook")
log.WithField("err", err).Fatal("failed getting mutating webhook")
}
for i := range mutHook.Webhooks {
@ -87,14 +96,9 @@ func (k8s *k8s) PatchWebhookConfigurations(
if _, err = k8s.clientset.AdmissionregistrationV1().
MutatingWebhookConfigurations().
Update(context.TODO(), mutHook, metav1.UpdateOptions{}); err != nil {
log.WithField("err", err).Fatal("failed patching validating webhook")
log.WithField("err", err).Fatal("failed patching mutating webhook")
}
log.Debug("patched mutating hook")
} else {
log.Debug("mutating hook patching not required")
}
log.Info("Patched hook(s)")
}
// GetCaFromSecret will check for the presence of a secret. If it exists, will return the content of the
@ -120,7 +124,6 @@ func (k8s *k8s) GetCaFromSecret(secretName string, namespace string) []byte {
// SaveCertsToSecret saves the provided ca, cert and key into a secret in the specified namespace.
func (k8s *k8s) SaveCertsToSecret(secretName, namespace, certName, keyName string, ca, cert, key []byte) {
log.Debugf("saving to secret '%s' in namespace '%s'", secretName, namespace)
secret := &v1.Secret{
ObjectMeta: metav1.ObjectMeta{

View file

@ -99,7 +99,8 @@ func TestPatchWebhookConfigurations(t *testing.T) {
ObjectMeta: metav1.ObjectMeta{
Name: testWebhookName,
},
Webhooks: []admissionv1.MutatingWebhook{{Name: "m1"}, {Name: "m2"}}}, metav1.CreateOptions{})
Webhooks: []admissionv1.MutatingWebhook{{Name: "m1"}, {Name: "m2"}},
}, metav1.CreateOptions{})
k.clientset.
AdmissionregistrationV1().
@ -109,7 +110,8 @@ func TestPatchWebhookConfigurations(t *testing.T) {
ObjectMeta: metav1.ObjectMeta{
Name: testWebhookName,
},
Webhooks: []admissionv1.ValidatingWebhook{{Name: "v1"}, {Name: "v2"}}}, metav1.CreateOptions{})
Webhooks: []admissionv1.ValidatingWebhook{{Name: "v1"}, {Name: "v2"}},
}, metav1.CreateOptions{})
k.PatchWebhookConfigurations(testWebhookName, ca, &fail, true, true)
@ -117,16 +119,14 @@ func TestPatchWebhookConfigurations(t *testing.T) {
AdmissionregistrationV1().
MutatingWebhookConfigurations().
Get(context.Background(), testWebhookName, metav1.GetOptions{})
if err != nil {
t.Error(err)
}
whval, err := k.clientset.
AdmissionregistrationV1beta1().
AdmissionregistrationV1().
MutatingWebhookConfigurations().
Get(context.Background(), testWebhookName, metav1.GetOptions{})
if err != nil {
t.Error(err)
}
@ -155,5 +155,4 @@ func TestPatchWebhookConfigurations(t *testing.T) {
if whval.Webhooks[1].FailurePolicy == nil {
t.Errorf("Expected second validating webhook failure policy to be set to %s", fail)
}
}