validatingwebhook.go

Documentation: sigs.k8s.io/controller-runtime/examples/builtins

     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 main
    18  
    19  import (
    20  	"context"
    21  	"fmt"
    22  
    23  	corev1 "k8s.io/api/core/v1"
    24  	"k8s.io/apimachinery/pkg/runtime"
    25  
    26  	logf "sigs.k8s.io/controller-runtime/pkg/log"
    27  	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
    28  )
    29  
    30  // +kubebuilder:webhook:path=/validate--v1-pod,mutating=false,failurePolicy=fail,groups="",resources=pods,verbs=create;update,versions=v1,name=vpod.kb.io
    31  
    32  // podValidator validates Pods
    33  type podValidator struct{}
    34  
    35  // validate admits a pod if a specific annotation exists.
    36  func (v *podValidator) validate(ctx context.Context, obj runtime.Object) (admission.Warnings, error) {
    37  	log := logf.FromContext(ctx)
    38  	pod, ok := obj.(*corev1.Pod)
    39  	if !ok {
    40  		return nil, fmt.Errorf("expected a Pod but got a %T", obj)
    41  	}
    42  
    43  	log.Info("Validating Pod")
    44  	key := "example-mutating-admission-webhook"
    45  	anno, found := pod.Annotations[key]
    46  	if !found {
    47  		return nil, fmt.Errorf("missing annotation %s", key)
    48  	}
    49  	if anno != "foo" {
    50  		return nil, fmt.Errorf("annotation %s did not have value %q", key, "foo")
    51  	}
    52  
    53  	return nil, nil
    54  }
    55  
    56  func (v *podValidator) ValidateCreate(ctx context.Context, obj runtime.Object) (admission.Warnings, error) {
    57  	return v.validate(ctx, obj)
    58  }
    59  
    60  func (v *podValidator) ValidateUpdate(ctx context.Context, oldObj, newObj runtime.Object) (admission.Warnings, error) {
    61  	return v.validate(ctx, newObj)
    62  }
    63  
    64  func (v *podValidator) ValidateDelete(ctx context.Context, obj runtime.Object) (admission.Warnings, error) {
    65  	return v.validate(ctx, obj)
    66  }
    67
View as plain text