mirror of
https://github.com/ceph/ceph-csi.git
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393 lines
12 KiB
Go
393 lines
12 KiB
Go
/*
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Copyright 2017 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package main
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import (
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"encoding/json"
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"flag"
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"fmt"
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"io/ioutil"
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"net/http"
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"strings"
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"github.com/golang/glog"
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"k8s.io/api/admission/v1beta1"
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corev1 "k8s.io/api/core/v1"
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apiextensionsv1beta1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
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metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
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"k8s.io/apimachinery/pkg/runtime"
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// TODO: try this library to see if it generates correct json patch
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// https://github.com/mattbaird/jsonpatch
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)
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const (
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patch1 string = `[
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{ "op": "add", "path": "/data/mutation-stage-1", "value": "yes" }
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]`
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patch2 string = `[
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{ "op": "add", "path": "/data/mutation-stage-2", "value": "yes" }
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]`
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addInitContainerPatch string = `[
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{"op":"add","path":"/spec/initContainers","value":[{"image":"webhook-added-image","name":"webhook-added-init-container","resources":{}}]}
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]`
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)
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// Config contains the server (the webhook) cert and key.
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type Config struct {
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CertFile string
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KeyFile string
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}
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func (c *Config) addFlags() {
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flag.StringVar(&c.CertFile, "tls-cert-file", c.CertFile, ""+
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"File containing the default x509 Certificate for HTTPS. (CA cert, if any, concatenated "+
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"after server cert).")
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flag.StringVar(&c.KeyFile, "tls-private-key-file", c.KeyFile, ""+
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"File containing the default x509 private key matching --tls-cert-file.")
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}
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func toAdmissionResponse(err error) *v1beta1.AdmissionResponse {
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return &v1beta1.AdmissionResponse{
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Result: &metav1.Status{
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Message: err.Error(),
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},
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}
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}
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// Deny all requests made to this function.
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func alwaysDeny(ar v1beta1.AdmissionReview) *v1beta1.AdmissionResponse {
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glog.V(2).Info("calling always-deny")
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reviewResponse := v1beta1.AdmissionResponse{}
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reviewResponse.Allowed = false
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reviewResponse.Result = &metav1.Status{Message: "this webhook denies all requests"}
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return &reviewResponse
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}
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// only allow pods to pull images from specific registry.
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func admitPods(ar v1beta1.AdmissionReview) *v1beta1.AdmissionResponse {
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glog.V(2).Info("admitting pods")
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podResource := metav1.GroupVersionResource{Group: "", Version: "v1", Resource: "pods"}
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if ar.Request.Resource != podResource {
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err := fmt.Errorf("expect resource to be %s", podResource)
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glog.Error(err)
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return toAdmissionResponse(err)
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}
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raw := ar.Request.Object.Raw
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pod := corev1.Pod{}
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deserializer := codecs.UniversalDeserializer()
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if _, _, err := deserializer.Decode(raw, nil, &pod); err != nil {
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glog.Error(err)
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return toAdmissionResponse(err)
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}
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reviewResponse := v1beta1.AdmissionResponse{}
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reviewResponse.Allowed = true
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var msg string
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if v, ok := pod.Labels["webhook-e2e-test"]; ok {
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if v == "webhook-disallow" {
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reviewResponse.Allowed = false
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msg = msg + "the pod contains unwanted label; "
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}
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if v == "wait-forever" {
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reviewResponse.Allowed = false
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msg = msg + "the pod response should not be sent; "
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<-make(chan int) // Sleep forever - no one sends to this channel
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}
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}
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for _, container := range pod.Spec.Containers {
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if strings.Contains(container.Name, "webhook-disallow") {
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reviewResponse.Allowed = false
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msg = msg + "the pod contains unwanted container name; "
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}
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}
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if !reviewResponse.Allowed {
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reviewResponse.Result = &metav1.Status{Message: strings.TrimSpace(msg)}
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}
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return &reviewResponse
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}
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func mutatePods(ar v1beta1.AdmissionReview) *v1beta1.AdmissionResponse {
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glog.V(2).Info("mutating pods")
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podResource := metav1.GroupVersionResource{Group: "", Version: "v1", Resource: "pods"}
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if ar.Request.Resource != podResource {
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glog.Errorf("expect resource to be %s", podResource)
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return nil
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}
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raw := ar.Request.Object.Raw
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pod := corev1.Pod{}
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deserializer := codecs.UniversalDeserializer()
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if _, _, err := deserializer.Decode(raw, nil, &pod); err != nil {
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glog.Error(err)
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return toAdmissionResponse(err)
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}
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reviewResponse := v1beta1.AdmissionResponse{}
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reviewResponse.Allowed = true
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if pod.Name == "webhook-to-be-mutated" {
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reviewResponse.Patch = []byte(addInitContainerPatch)
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pt := v1beta1.PatchTypeJSONPatch
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reviewResponse.PatchType = &pt
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}
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return &reviewResponse
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}
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// deny configmaps with specific key-value pair.
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func admitConfigMaps(ar v1beta1.AdmissionReview) *v1beta1.AdmissionResponse {
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glog.V(2).Info("admitting configmaps")
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configMapResource := metav1.GroupVersionResource{Group: "", Version: "v1", Resource: "configmaps"}
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if ar.Request.Resource != configMapResource {
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glog.Errorf("expect resource to be %s", configMapResource)
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return nil
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}
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raw := ar.Request.Object.Raw
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configmap := corev1.ConfigMap{}
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deserializer := codecs.UniversalDeserializer()
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if _, _, err := deserializer.Decode(raw, nil, &configmap); err != nil {
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glog.Error(err)
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return toAdmissionResponse(err)
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}
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reviewResponse := v1beta1.AdmissionResponse{}
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reviewResponse.Allowed = true
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for k, v := range configmap.Data {
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if k == "webhook-e2e-test" && v == "webhook-disallow" {
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reviewResponse.Allowed = false
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reviewResponse.Result = &metav1.Status{
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Reason: "the configmap contains unwanted key and value",
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}
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}
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}
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return &reviewResponse
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}
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func mutateConfigmaps(ar v1beta1.AdmissionReview) *v1beta1.AdmissionResponse {
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glog.V(2).Info("mutating configmaps")
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configMapResource := metav1.GroupVersionResource{Group: "", Version: "v1", Resource: "configmaps"}
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if ar.Request.Resource != configMapResource {
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glog.Errorf("expect resource to be %s", configMapResource)
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return nil
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}
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raw := ar.Request.Object.Raw
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configmap := corev1.ConfigMap{}
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deserializer := codecs.UniversalDeserializer()
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if _, _, err := deserializer.Decode(raw, nil, &configmap); err != nil {
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glog.Error(err)
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return toAdmissionResponse(err)
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}
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reviewResponse := v1beta1.AdmissionResponse{}
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reviewResponse.Allowed = true
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if configmap.Data["mutation-start"] == "yes" {
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reviewResponse.Patch = []byte(patch1)
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}
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if configmap.Data["mutation-stage-1"] == "yes" {
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reviewResponse.Patch = []byte(patch2)
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}
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pt := v1beta1.PatchTypeJSONPatch
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reviewResponse.PatchType = &pt
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return &reviewResponse
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}
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func mutateCustomResource(ar v1beta1.AdmissionReview) *v1beta1.AdmissionResponse {
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glog.V(2).Info("mutating custom resource")
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cr := struct {
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metav1.ObjectMeta
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Data map[string]string
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}{}
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raw := ar.Request.Object.Raw
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err := json.Unmarshal(raw, &cr)
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if err != nil {
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glog.Error(err)
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return toAdmissionResponse(err)
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}
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reviewResponse := v1beta1.AdmissionResponse{}
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reviewResponse.Allowed = true
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if cr.Data["mutation-start"] == "yes" {
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reviewResponse.Patch = []byte(patch1)
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}
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if cr.Data["mutation-stage-1"] == "yes" {
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reviewResponse.Patch = []byte(patch2)
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}
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pt := v1beta1.PatchTypeJSONPatch
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reviewResponse.PatchType = &pt
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return &reviewResponse
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}
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func admitCustomResource(ar v1beta1.AdmissionReview) *v1beta1.AdmissionResponse {
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glog.V(2).Info("admitting custom resource")
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cr := struct {
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metav1.ObjectMeta
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Data map[string]string
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}{}
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raw := ar.Request.Object.Raw
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err := json.Unmarshal(raw, &cr)
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if err != nil {
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glog.Error(err)
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return toAdmissionResponse(err)
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}
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reviewResponse := v1beta1.AdmissionResponse{}
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reviewResponse.Allowed = true
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for k, v := range cr.Data {
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if k == "webhook-e2e-test" && v == "webhook-disallow" {
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reviewResponse.Allowed = false
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reviewResponse.Result = &metav1.Status{
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Reason: "the custom resource contains unwanted data",
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}
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}
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}
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return &reviewResponse
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}
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// Deny all crds with the label "webhook-e2e-test":"webhook-disallow"
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// This function expects all CRDs submitted to it to be apiextensions.k8s.io/v1beta1
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// TODO: When apiextensions.k8s.io/v1 is added we will need to update this function.
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func admitCRD(ar v1beta1.AdmissionReview) *v1beta1.AdmissionResponse {
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glog.V(2).Info("admitting crd")
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crdResource := metav1.GroupVersionResource{Group: "apiextensions.k8s.io", Version: "v1beta1", Resource: "customresourcedefinitions"}
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if ar.Request.Resource != crdResource {
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err := fmt.Errorf("expect resource to be %s", crdResource)
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glog.Error(err)
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return toAdmissionResponse(err)
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}
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raw := ar.Request.Object.Raw
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crd := apiextensionsv1beta1.CustomResourceDefinition{}
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deserializer := codecs.UniversalDeserializer()
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if _, _, err := deserializer.Decode(raw, nil, &crd); err != nil {
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glog.Error(err)
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return toAdmissionResponse(err)
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}
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reviewResponse := v1beta1.AdmissionResponse{}
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reviewResponse.Allowed = true
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if v, ok := crd.Labels["webhook-e2e-test"]; ok {
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if v == "webhook-disallow" {
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reviewResponse.Allowed = false
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reviewResponse.Result = &metav1.Status{Message: "the crd contains unwanted label"}
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}
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}
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return &reviewResponse
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}
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type admitFunc func(v1beta1.AdmissionReview) *v1beta1.AdmissionResponse
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func serve(w http.ResponseWriter, r *http.Request, admit admitFunc) {
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var body []byte
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if r.Body != nil {
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if data, err := ioutil.ReadAll(r.Body); err == nil {
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body = data
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}
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}
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// verify the content type is accurate
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contentType := r.Header.Get("Content-Type")
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if contentType != "application/json" {
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glog.Errorf("contentType=%s, expect application/json", contentType)
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return
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}
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glog.V(2).Info(fmt.Sprintf("handling request: %v", body))
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var reviewResponse *v1beta1.AdmissionResponse
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ar := v1beta1.AdmissionReview{}
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deserializer := codecs.UniversalDeserializer()
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if _, _, err := deserializer.Decode(body, nil, &ar); err != nil {
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glog.Error(err)
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reviewResponse = toAdmissionResponse(err)
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} else {
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reviewResponse = admit(ar)
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}
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glog.V(2).Info(fmt.Sprintf("sending response: %v", reviewResponse))
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response := v1beta1.AdmissionReview{}
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if reviewResponse != nil {
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response.Response = reviewResponse
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response.Response.UID = ar.Request.UID
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}
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// reset the Object and OldObject, they are not needed in a response.
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ar.Request.Object = runtime.RawExtension{}
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ar.Request.OldObject = runtime.RawExtension{}
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resp, err := json.Marshal(response)
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if err != nil {
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glog.Error(err)
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}
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if _, err := w.Write(resp); err != nil {
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glog.Error(err)
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}
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}
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func serveAlwaysDeny(w http.ResponseWriter, r *http.Request) {
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serve(w, r, alwaysDeny)
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}
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func servePods(w http.ResponseWriter, r *http.Request) {
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serve(w, r, admitPods)
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}
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func serveMutatePods(w http.ResponseWriter, r *http.Request) {
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serve(w, r, mutatePods)
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}
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func serveConfigmaps(w http.ResponseWriter, r *http.Request) {
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serve(w, r, admitConfigMaps)
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}
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func serveMutateConfigmaps(w http.ResponseWriter, r *http.Request) {
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serve(w, r, mutateConfigmaps)
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}
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func serveCustomResource(w http.ResponseWriter, r *http.Request) {
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serve(w, r, admitCustomResource)
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}
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func serveMutateCustomResource(w http.ResponseWriter, r *http.Request) {
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serve(w, r, mutateCustomResource)
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}
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func serveCRD(w http.ResponseWriter, r *http.Request) {
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serve(w, r, admitCRD)
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}
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func main() {
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var config Config
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config.addFlags()
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flag.Parse()
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http.HandleFunc("/always-deny", serveAlwaysDeny)
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http.HandleFunc("/pods", servePods)
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http.HandleFunc("/mutating-pods", serveMutatePods)
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http.HandleFunc("/configmaps", serveConfigmaps)
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http.HandleFunc("/mutating-configmaps", serveMutateConfigmaps)
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http.HandleFunc("/custom-resource", serveCustomResource)
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http.HandleFunc("/mutating-custom-resource", serveMutateCustomResource)
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http.HandleFunc("/crd", serveCRD)
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clientset := getClient()
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server := &http.Server{
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Addr: ":443",
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TLSConfig: configTLS(config, clientset),
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}
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server.ListenAndServeTLS("", "")
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}
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