k8s.io/apiserver@v0.31.1/pkg/admission/testing/helpers.go (about)

     1  /*
     2  Copyright 2019 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 testing
    18  
    19  import (
    20  	"context"
    21  	"reflect"
    22  	"testing"
    23  
    24  	"github.com/google/go-cmp/cmp"
    25  	apiequality "k8s.io/apimachinery/pkg/api/equality"
    26  	"k8s.io/apimachinery/pkg/runtime"
    27  	"k8s.io/apiserver/pkg/admission"
    28  )
    29  
    30  // WithReinvocationTesting wraps a mutating admission handler and reinvokes it each time Admit is
    31  // called. It checks the admission output object and reports a test error if the admission handler
    32  // performs non-idempotent mutatations to the object.
    33  func WithReinvocationTesting(t *testing.T, admission admission.MutationInterface) admission.MutationInterface {
    34  	return &reinvoker{t, admission}
    35  }
    36  
    37  type reinvoker struct {
    38  	t         *testing.T
    39  	admission admission.MutationInterface
    40  }
    41  
    42  // Admit reinvokes the admission handler and reports a test error if the admission handler performs
    43  // non-idempotent mutatations to the admission object.
    44  func (r *reinvoker) Admit(ctx context.Context, a admission.Attributes, o admission.ObjectInterfaces) error {
    45  	r.t.Helper()
    46  	outputs := []runtime.Object{}
    47  	for i := 0; i < 2; i++ {
    48  		err := r.admission.Admit(ctx, a, o)
    49  		if err != nil {
    50  			return err
    51  		}
    52  		if a.GetObject() != nil {
    53  			// keep a copy of the output for subsequent idempotency checking
    54  			outputs = append(outputs, a.GetObject().DeepCopyObject())
    55  			// replace a.GetObject() with a copy of itself to make sure admission is safe to reinvoke with a round-tripped copy (no pointer comparisons are done)
    56  			if deepCopyInto, ok := reflect.TypeOf(a.GetObject()).MethodByName("DeepCopyInto"); ok {
    57  				deepCopyInto.Func.Call([]reflect.Value{
    58  					reflect.ValueOf(a.GetObject().DeepCopyObject()),
    59  					reflect.ValueOf(a.GetObject()),
    60  				})
    61  			}
    62  		}
    63  	}
    64  	for i := 1; i < len(outputs); i++ {
    65  		if !apiequality.Semantic.DeepEqual(outputs[0], outputs[i]) {
    66  			r.t.Errorf("expected mutating admission plugin to be idempontent, but got different results on reinvocation, diff:\n%s", cmp.Diff(outputs[0], outputs[i]))
    67  		}
    68  	}
    69  	return nil
    70  }
    71  
    72  // Handles will return true if any of the admission andler handlers handle the given operation.
    73  func (r *reinvoker) Handles(operation admission.Operation) bool {
    74  	r.t.Helper()
    75  	return r.admission.Handles(operation)
    76  }