apiserver/pkg/admission/plugin/webhook/validating/admission_test.go

675 lines
18 KiB
Go

/*
Copyright 2017 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 validating
import (
"crypto/tls"
"crypto/x509"
"encoding/json"
"fmt"
"net/http"
"net/http/httptest"
"net/url"
"strings"
"sync/atomic"
"testing"
"k8s.io/api/admission/v1alpha1"
registrationv1alpha1 "k8s.io/api/admissionregistration/v1alpha1"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/api/errors"
apierrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apiserver/pkg/admission"
"k8s.io/apiserver/pkg/admission/plugin/webhook/config"
"k8s.io/apiserver/pkg/admission/plugin/webhook/testdata"
"k8s.io/apiserver/pkg/authentication/user"
"k8s.io/client-go/rest"
)
type fakeHookSource struct {
hooks []registrationv1alpha1.Webhook
err error
}
func (f *fakeHookSource) Webhooks() (*registrationv1alpha1.ValidatingWebhookConfiguration, error) {
if f.err != nil {
return nil, f.err
}
for i, h := range f.hooks {
if h.NamespaceSelector == nil {
f.hooks[i].NamespaceSelector = &metav1.LabelSelector{}
}
}
return &registrationv1alpha1.ValidatingWebhookConfiguration{Webhooks: f.hooks}, nil
}
func (f *fakeHookSource) Run(stopCh <-chan struct{}) {}
type fakeServiceResolver struct {
base url.URL
}
func (f fakeServiceResolver) ResolveEndpoint(namespace, name string) (*url.URL, error) {
if namespace == "failResolve" {
return nil, fmt.Errorf("couldn't resolve service location")
}
u := f.base
return &u, nil
}
type fakeNamespaceLister struct {
namespaces map[string]*corev1.Namespace
}
func (f fakeNamespaceLister) List(selector labels.Selector) (ret []*corev1.Namespace, err error) {
return nil, nil
}
func (f fakeNamespaceLister) Get(name string) (*corev1.Namespace, error) {
ns, ok := f.namespaces[name]
if ok {
return ns, nil
}
return nil, errors.NewNotFound(corev1.Resource("namespaces"), name)
}
// ccfgSVC returns a client config using the service reference mechanism.
func ccfgSVC(urlPath string) registrationv1alpha1.WebhookClientConfig {
return registrationv1alpha1.WebhookClientConfig{
Service: &registrationv1alpha1.ServiceReference{
Name: "webhook-test",
Namespace: "default",
Path: &urlPath,
},
CABundle: testdata.CACert,
}
}
type urlConfigGenerator struct {
baseURL *url.URL
}
// ccfgURL returns a client config using the URL mechanism.
func (c urlConfigGenerator) ccfgURL(urlPath string) registrationv1alpha1.WebhookClientConfig {
u2 := *c.baseURL
u2.Path = urlPath
urlString := u2.String()
return registrationv1alpha1.WebhookClientConfig{
URL: &urlString,
CABundle: testdata.CACert,
}
}
// TestAdmit tests that GenericAdmissionWebhook#Admit works as expected
func TestAdmit(t *testing.T) {
scheme := runtime.NewScheme()
v1alpha1.AddToScheme(scheme)
corev1.AddToScheme(scheme)
testServer := newTestServer(t)
testServer.StartTLS()
defer testServer.Close()
serverURL, err := url.ParseRequestURI(testServer.URL)
if err != nil {
t.Fatalf("this should never happen? %v", err)
}
wh, err := NewGenericAdmissionWebhook(nil)
if err != nil {
t.Fatal(err)
}
cm, err := config.NewClientManager()
if err != nil {
t.Fatalf("cannot create client manager: %v", err)
}
cm.SetAuthenticationInfoResolver(newFakeAuthenticationInfoResolver(new(int32)))
cm.SetServiceResolver(fakeServiceResolver{base: *serverURL})
wh.clientManager = cm
wh.SetScheme(scheme)
if err = wh.clientManager.Validate(); err != nil {
t.Fatal(err)
}
namespace := "webhook-test"
wh.namespaceMatcher.NamespaceLister = fakeNamespaceLister{map[string]*corev1.Namespace{
namespace: {
ObjectMeta: metav1.ObjectMeta{
Labels: map[string]string{
"runlevel": "0",
},
},
},
},
}
// Set up a test object for the call
kind := corev1.SchemeGroupVersion.WithKind("Pod")
name := "my-pod"
object := corev1.Pod{
ObjectMeta: metav1.ObjectMeta{
Labels: map[string]string{
"pod.name": name,
},
Name: name,
Namespace: namespace,
},
TypeMeta: metav1.TypeMeta{
APIVersion: "v1",
Kind: "Pod",
},
}
oldObject := corev1.Pod{
ObjectMeta: metav1.ObjectMeta{Name: name, Namespace: namespace},
}
operation := admission.Update
resource := corev1.Resource("pods").WithVersion("v1")
subResource := ""
userInfo := user.DefaultInfo{
Name: "webhook-test",
UID: "webhook-test",
}
ccfgURL := urlConfigGenerator{serverURL}.ccfgURL
type test struct {
hookSource fakeHookSource
path string
expectAllow bool
errorContains string
}
matchEverythingRules := []registrationv1alpha1.RuleWithOperations{{
Operations: []registrationv1alpha1.OperationType{registrationv1alpha1.OperationAll},
Rule: registrationv1alpha1.Rule{
APIGroups: []string{"*"},
APIVersions: []string{"*"},
Resources: []string{"*/*"},
},
}}
policyFail := registrationv1alpha1.Fail
policyIgnore := registrationv1alpha1.Ignore
table := map[string]test{
"no match": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "nomatch",
ClientConfig: ccfgSVC("disallow"),
Rules: []registrationv1alpha1.RuleWithOperations{{
Operations: []registrationv1alpha1.OperationType{registrationv1alpha1.Create},
}},
}},
},
expectAllow: true,
},
"match & allow": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "allow",
ClientConfig: ccfgSVC("allow"),
Rules: matchEverythingRules,
}},
},
expectAllow: true,
},
"match & disallow": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "disallow",
ClientConfig: ccfgSVC("disallow"),
Rules: matchEverythingRules,
}},
},
errorContains: "without explanation",
},
"match & disallow ii": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "disallowReason",
ClientConfig: ccfgSVC("disallowReason"),
Rules: matchEverythingRules,
}},
},
errorContains: "you shall not pass",
},
"match & disallow & but allowed because namespaceSelector exempt the namespace": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "disallow",
ClientConfig: ccfgSVC("disallow"),
Rules: newMatchEverythingRules(),
NamespaceSelector: &metav1.LabelSelector{
MatchExpressions: []metav1.LabelSelectorRequirement{{
Key: "runlevel",
Values: []string{"1"},
Operator: metav1.LabelSelectorOpIn,
}},
},
}},
},
expectAllow: true,
},
"match & disallow & but allowed because namespaceSelector exempt the namespace ii": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "disallow",
ClientConfig: ccfgSVC("disallow"),
Rules: newMatchEverythingRules(),
NamespaceSelector: &metav1.LabelSelector{
MatchExpressions: []metav1.LabelSelectorRequirement{{
Key: "runlevel",
Values: []string{"0"},
Operator: metav1.LabelSelectorOpNotIn,
}},
},
}},
},
expectAllow: true,
},
"match & fail (but allow because fail open)": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "internalErr A",
ClientConfig: ccfgSVC("internalErr"),
Rules: matchEverythingRules,
FailurePolicy: &policyIgnore,
}, {
Name: "internalErr B",
ClientConfig: ccfgSVC("internalErr"),
Rules: matchEverythingRules,
FailurePolicy: &policyIgnore,
}, {
Name: "internalErr C",
ClientConfig: ccfgSVC("internalErr"),
Rules: matchEverythingRules,
FailurePolicy: &policyIgnore,
}},
},
expectAllow: true,
},
"match & fail (but disallow because fail closed on nil)": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "internalErr A",
ClientConfig: ccfgSVC("internalErr"),
Rules: matchEverythingRules,
}, {
Name: "internalErr B",
ClientConfig: ccfgSVC("internalErr"),
Rules: matchEverythingRules,
}, {
Name: "internalErr C",
ClientConfig: ccfgSVC("internalErr"),
Rules: matchEverythingRules,
}},
},
expectAllow: false,
},
"match & fail (but fail because fail closed)": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "internalErr A",
ClientConfig: ccfgSVC("internalErr"),
Rules: matchEverythingRules,
FailurePolicy: &policyFail,
}, {
Name: "internalErr B",
ClientConfig: ccfgSVC("internalErr"),
Rules: matchEverythingRules,
FailurePolicy: &policyFail,
}, {
Name: "internalErr C",
ClientConfig: ccfgSVC("internalErr"),
Rules: matchEverythingRules,
FailurePolicy: &policyFail,
}},
},
expectAllow: false,
},
"match & allow (url)": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "allow",
ClientConfig: ccfgURL("allow"),
Rules: matchEverythingRules,
}},
},
expectAllow: true,
},
"match & disallow (url)": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "disallow",
ClientConfig: ccfgURL("disallow"),
Rules: matchEverythingRules,
}},
},
errorContains: "without explanation",
},
"absent response and fail open": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "nilResponse",
ClientConfig: ccfgURL("nilResponse"),
FailurePolicy: &policyIgnore,
Rules: matchEverythingRules,
}},
},
expectAllow: true,
},
"absent response and fail closed": {
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "nilResponse",
ClientConfig: ccfgURL("nilResponse"),
FailurePolicy: &policyFail,
Rules: matchEverythingRules,
}},
},
errorContains: "Webhook response was absent",
},
// No need to test everything with the url case, since only the
// connection is different.
}
for name, tt := range table {
if !strings.Contains(name, "no match") {
continue
}
t.Run(name, func(t *testing.T) {
wh.hookSource = &tt.hookSource
err = wh.Admit(admission.NewAttributesRecord(&object, &oldObject, kind, namespace, name, resource, subResource, operation, &userInfo))
if tt.expectAllow != (err == nil) {
t.Errorf("expected allowed=%v, but got err=%v", tt.expectAllow, err)
}
// ErrWebhookRejected is not an error for our purposes
if tt.errorContains != "" {
if err == nil || !strings.Contains(err.Error(), tt.errorContains) {
t.Errorf(" expected an error saying %q, but got %v", tt.errorContains, err)
}
}
if _, isStatusErr := err.(*apierrors.StatusError); err != nil && !isStatusErr {
t.Errorf("%s: expected a StatusError, got %T", name, err)
}
})
}
}
// TestAdmitCachedClient tests that GenericAdmissionWebhook#Admit should cache restClient
func TestAdmitCachedClient(t *testing.T) {
scheme := runtime.NewScheme()
v1alpha1.AddToScheme(scheme)
corev1.AddToScheme(scheme)
testServer := newTestServer(t)
testServer.StartTLS()
defer testServer.Close()
serverURL, err := url.ParseRequestURI(testServer.URL)
if err != nil {
t.Fatalf("this should never happen? %v", err)
}
wh, err := NewGenericAdmissionWebhook(nil)
if err != nil {
t.Fatal(err)
}
cm, err := config.NewClientManager()
if err != nil {
t.Fatalf("cannot create client manager: %v", err)
}
cm.SetServiceResolver(fakeServiceResolver{base: *serverURL})
wh.clientManager = cm
wh.SetScheme(scheme)
namespace := "webhook-test"
wh.namespaceMatcher.NamespaceLister = fakeNamespaceLister{map[string]*corev1.Namespace{
namespace: {
ObjectMeta: metav1.ObjectMeta{
Labels: map[string]string{
"runlevel": "0",
},
},
},
},
}
// Set up a test object for the call
kind := corev1.SchemeGroupVersion.WithKind("Pod")
name := "my-pod"
object := corev1.Pod{
ObjectMeta: metav1.ObjectMeta{
Labels: map[string]string{
"pod.name": name,
},
Name: name,
Namespace: namespace,
},
TypeMeta: metav1.TypeMeta{
APIVersion: "v1",
Kind: "Pod",
},
}
oldObject := corev1.Pod{
ObjectMeta: metav1.ObjectMeta{Name: name, Namespace: namespace},
}
operation := admission.Update
resource := corev1.Resource("pods").WithVersion("v1")
subResource := ""
userInfo := user.DefaultInfo{
Name: "webhook-test",
UID: "webhook-test",
}
ccfgURL := urlConfigGenerator{serverURL}.ccfgURL
type test struct {
name string
hookSource fakeHookSource
expectAllow bool
expectCache bool
}
policyIgnore := registrationv1alpha1.Ignore
cases := []test{
{
name: "cache 1",
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "cache1",
ClientConfig: ccfgSVC("allow"),
Rules: newMatchEverythingRules(),
FailurePolicy: &policyIgnore,
}},
},
expectAllow: true,
expectCache: true,
},
{
name: "cache 2",
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "cache2",
ClientConfig: ccfgSVC("internalErr"),
Rules: newMatchEverythingRules(),
FailurePolicy: &policyIgnore,
}},
},
expectAllow: true,
expectCache: true,
},
{
name: "cache 3",
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "cache3",
ClientConfig: ccfgSVC("allow"),
Rules: newMatchEverythingRules(),
FailurePolicy: &policyIgnore,
}},
},
expectAllow: true,
expectCache: false,
},
{
name: "cache 4",
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "cache4",
ClientConfig: ccfgURL("allow"),
Rules: newMatchEverythingRules(),
FailurePolicy: &policyIgnore,
}},
},
expectAllow: true,
expectCache: true,
},
{
name: "cache 5",
hookSource: fakeHookSource{
hooks: []registrationv1alpha1.Webhook{{
Name: "cache5",
ClientConfig: ccfgURL("allow"),
Rules: newMatchEverythingRules(),
FailurePolicy: &policyIgnore,
}},
},
expectAllow: true,
expectCache: false,
},
}
for _, testcase := range cases {
t.Run(testcase.name, func(t *testing.T) {
wh.hookSource = &testcase.hookSource
authInfoResolverCount := new(int32)
r := newFakeAuthenticationInfoResolver(authInfoResolverCount)
wh.clientManager.SetAuthenticationInfoResolver(r)
if err = wh.clientManager.Validate(); err != nil {
t.Fatal(err)
}
err = wh.Admit(admission.NewAttributesRecord(&object, &oldObject, kind, namespace, testcase.name, resource, subResource, operation, &userInfo))
if testcase.expectAllow != (err == nil) {
t.Errorf("expected allowed=%v, but got err=%v", testcase.expectAllow, err)
}
if testcase.expectCache && *authInfoResolverCount != 1 {
t.Errorf("expected cacheclient, but got none")
}
if !testcase.expectCache && *authInfoResolverCount != 0 {
t.Errorf("expected not cacheclient, but got cache")
}
})
}
}
func newTestServer(t *testing.T) *httptest.Server {
// Create the test webhook server
sCert, err := tls.X509KeyPair(testdata.ServerCert, testdata.ServerKey)
if err != nil {
t.Fatal(err)
}
rootCAs := x509.NewCertPool()
rootCAs.AppendCertsFromPEM(testdata.CACert)
testServer := httptest.NewUnstartedServer(http.HandlerFunc(webhookHandler))
testServer.TLS = &tls.Config{
Certificates: []tls.Certificate{sCert},
ClientCAs: rootCAs,
ClientAuth: tls.RequireAndVerifyClientCert,
}
return testServer
}
func webhookHandler(w http.ResponseWriter, r *http.Request) {
fmt.Printf("got req: %v\n", r.URL.Path)
switch r.URL.Path {
case "/internalErr":
http.Error(w, "webhook internal server error", http.StatusInternalServerError)
return
case "/invalidReq":
w.WriteHeader(http.StatusSwitchingProtocols)
w.Write([]byte("webhook invalid request"))
return
case "/invalidResp":
w.Header().Set("Content-Type", "application/json")
w.Write([]byte("webhook invalid response"))
case "/disallow":
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(&v1alpha1.AdmissionReview{
Response: &v1alpha1.AdmissionResponse{
Allowed: false,
},
})
case "/disallowReason":
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(&v1alpha1.AdmissionReview{
Response: &v1alpha1.AdmissionResponse{
Allowed: false,
Result: &metav1.Status{
Message: "you shall not pass",
},
},
})
case "/allow":
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(&v1alpha1.AdmissionReview{
Response: &v1alpha1.AdmissionResponse{
Allowed: true,
},
})
case "/nilResposne":
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(&v1alpha1.AdmissionReview{})
default:
http.NotFound(w, r)
}
}
func newFakeAuthenticationInfoResolver(count *int32) *fakeAuthenticationInfoResolver {
return &fakeAuthenticationInfoResolver{
restConfig: &rest.Config{
TLSClientConfig: rest.TLSClientConfig{
CAData: testdata.CACert,
CertData: testdata.ClientCert,
KeyData: testdata.ClientKey,
},
},
cachedCount: count,
}
}
type fakeAuthenticationInfoResolver struct {
restConfig *rest.Config
cachedCount *int32
}
func (c *fakeAuthenticationInfoResolver) ClientConfigFor(server string) (*rest.Config, error) {
atomic.AddInt32(c.cachedCount, 1)
return c.restConfig, nil
}
func newMatchEverythingRules() []registrationv1alpha1.RuleWithOperations {
return []registrationv1alpha1.RuleWithOperations{{
Operations: []registrationv1alpha1.OperationType{registrationv1alpha1.OperationAll},
Rule: registrationv1alpha1.Rule{
APIGroups: []string{"*"},
APIVersions: []string{"*"},
Resources: []string{"*/*"},
},
}}
}