configmap.go

Documentation: k8s.io/kubernetes/test/images/agnhost/webhook

     1  /*
     2  Copyright 2018 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package webhook
    18  
    19  import (
    20  	v1 "k8s.io/api/admission/v1"
    21  	corev1 "k8s.io/api/core/v1"
    22  	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    23  	"k8s.io/klog/v2"
    24  )
    25  
    26  const (
    27  	configMapPatch1 string = `[
    28           { "op": "add", "path": "/data/mutation-stage-1", "value": "yes" }
    29       ]`
    30  	configMapPatch2 string = `[
    31           { "op": "add", "path": "/data/mutation-stage-2", "value": "yes" }
    32       ]`
    33  )
    34  
    35  // deny configmaps with specific key-value pair.
    36  func admitConfigMaps(ar v1.AdmissionReview) *v1.AdmissionResponse {
    37  	klog.V(2).Info("admitting configmaps")
    38  	configMapResource := metav1.GroupVersionResource{Group: "", Version: "v1", Resource: "configmaps"}
    39  	if ar.Request.Resource != configMapResource {
    40  		klog.Errorf("expect resource to be %s", configMapResource)
    41  		return nil
    42  	}
    43  
    44  	var raw []byte
    45  	if ar.Request.Operation == v1.Delete {
    46  		raw = ar.Request.OldObject.Raw
    47  	} else {
    48  		raw = ar.Request.Object.Raw
    49  	}
    50  	configmap := corev1.ConfigMap{}
    51  	deserializer := codecs.UniversalDeserializer()
    52  	if _, _, err := deserializer.Decode(raw, nil, &configmap); err != nil {
    53  		klog.Error(err)
    54  		return toV1AdmissionResponse(err)
    55  	}
    56  	reviewResponse := v1.AdmissionResponse{}
    57  	reviewResponse.Allowed = true
    58  	for k, v := range configmap.Data {
    59  		if k == "webhook-e2e-test" && v == "webhook-disallow" &&
    60  			(ar.Request.Operation == v1.Create || ar.Request.Operation == v1.Update) {
    61  			reviewResponse.Allowed = false
    62  			reviewResponse.Result = &metav1.Status{
    63  				Reason: "the configmap contains unwanted key and value",
    64  			}
    65  		}
    66  		if k == "webhook-e2e-test" && v == "webhook-nondeletable" && ar.Request.Operation == v1.Delete {
    67  			reviewResponse.Allowed = false
    68  			reviewResponse.Result = &metav1.Status{
    69  				Reason: "the configmap cannot be deleted because it contains unwanted key and value",
    70  			}
    71  		}
    72  	}
    73  	return &reviewResponse
    74  }
    75  
    76  func mutateConfigmaps(ar v1.AdmissionReview) *v1.AdmissionResponse {
    77  	klog.V(2).Info("mutating configmaps")
    78  	configMapResource := metav1.GroupVersionResource{Group: "", Version: "v1", Resource: "configmaps"}
    79  	if ar.Request.Resource != configMapResource {
    80  		klog.Errorf("expect resource to be %s", configMapResource)
    81  		return nil
    82  	}
    83  
    84  	raw := ar.Request.Object.Raw
    85  	configmap := corev1.ConfigMap{}
    86  	deserializer := codecs.UniversalDeserializer()
    87  	if _, _, err := deserializer.Decode(raw, nil, &configmap); err != nil {
    88  		klog.Error(err)
    89  		return toV1AdmissionResponse(err)
    90  	}
    91  	reviewResponse := v1.AdmissionResponse{}
    92  	reviewResponse.Allowed = true
    93  	if configmap.Data["mutation-start"] == "yes" {
    94  		reviewResponse.Patch = []byte(configMapPatch1)
    95  	}
    96  	if configmap.Data["mutation-stage-1"] == "yes" {
    97  		reviewResponse.Patch = []byte(configMapPatch2)
    98  	}
    99  
   100  	if len(reviewResponse.Patch) != 0 {
   101  		pt := v1.PatchTypeJSONPatch
   102  		reviewResponse.PatchType = &pt
   103  	}
   104  
   105  	return &reviewResponse
   106  }
   107
View as plain text