strategy.go

Documentation: k8s.io/kubernetes/pkg/registry/discovery/endpointslice

     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 endpointslice
    18  
    19  import (
    20  	"context"
    21  	"fmt"
    22  
    23  	corev1 "k8s.io/api/core/v1"
    24  	discoveryv1beta1 "k8s.io/api/discovery/v1beta1"
    25  	apiequality "k8s.io/apimachinery/pkg/api/equality"
    26  	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    27  	"k8s.io/apimachinery/pkg/runtime"
    28  	"k8s.io/apimachinery/pkg/runtime/schema"
    29  	"k8s.io/apimachinery/pkg/util/sets"
    30  	"k8s.io/apimachinery/pkg/util/validation/field"
    31  	genericapirequest "k8s.io/apiserver/pkg/endpoints/request"
    32  	"k8s.io/apiserver/pkg/storage/names"
    33  	utilfeature "k8s.io/apiserver/pkg/util/feature"
    34  	"k8s.io/kubernetes/pkg/api/legacyscheme"
    35  	apivalidation "k8s.io/kubernetes/pkg/apis/core/validation"
    36  	"k8s.io/kubernetes/pkg/apis/discovery"
    37  	"k8s.io/kubernetes/pkg/apis/discovery/validation"
    38  	"k8s.io/kubernetes/pkg/features"
    39  )
    40  
    41  // endpointSliceStrategy implements verification logic for Replication.
    42  type endpointSliceStrategy struct {
    43  	runtime.ObjectTyper
    44  	names.NameGenerator
    45  }
    46  
    47  // Strategy is the default logic that applies when creating and updating Replication EndpointSlice objects.
    48  var Strategy = endpointSliceStrategy{legacyscheme.Scheme, names.SimpleNameGenerator}
    49  
    50  // NamespaceScoped returns true because all EndpointSlices need to be within a namespace.
    51  func (endpointSliceStrategy) NamespaceScoped() bool {
    52  	return true
    53  }
    54  
    55  // PrepareForCreate clears the status of an EndpointSlice before creation.
    56  func (endpointSliceStrategy) PrepareForCreate(ctx context.Context, obj runtime.Object) {
    57  	endpointSlice := obj.(*discovery.EndpointSlice)
    58  	endpointSlice.Generation = 1
    59  
    60  	dropDisabledFieldsOnCreate(endpointSlice)
    61  	dropTopologyOnV1(ctx, nil, endpointSlice)
    62  }
    63  
    64  // PrepareForUpdate clears fields that are not allowed to be set by end users on update.
    65  func (endpointSliceStrategy) PrepareForUpdate(ctx context.Context, obj, old runtime.Object) {
    66  	newEPS := obj.(*discovery.EndpointSlice)
    67  	oldEPS := old.(*discovery.EndpointSlice)
    68  
    69  	// Increment generation if anything other than meta changed
    70  	// This needs to be changed if a status attribute is added to EndpointSlice
    71  	ogNewMeta := newEPS.ObjectMeta
    72  	ogOldMeta := oldEPS.ObjectMeta
    73  	newEPS.ObjectMeta = metav1.ObjectMeta{}
    74  	oldEPS.ObjectMeta = metav1.ObjectMeta{}
    75  
    76  	if !apiequality.Semantic.DeepEqual(newEPS, oldEPS) || !apiequality.Semantic.DeepEqual(ogNewMeta.Labels, ogOldMeta.Labels) {
    77  		ogNewMeta.Generation = ogOldMeta.Generation + 1
    78  	}
    79  
    80  	newEPS.ObjectMeta = ogNewMeta
    81  	oldEPS.ObjectMeta = ogOldMeta
    82  
    83  	dropDisabledFieldsOnUpdate(oldEPS, newEPS)
    84  	dropTopologyOnV1(ctx, oldEPS, newEPS)
    85  }
    86  
    87  // Validate validates a new EndpointSlice.
    88  func (endpointSliceStrategy) Validate(ctx context.Context, obj runtime.Object) field.ErrorList {
    89  	endpointSlice := obj.(*discovery.EndpointSlice)
    90  	err := validation.ValidateEndpointSliceCreate(endpointSlice)
    91  	return err
    92  }
    93  
    94  // WarningsOnCreate returns warnings for the creation of the given object.
    95  func (endpointSliceStrategy) WarningsOnCreate(ctx context.Context, obj runtime.Object) []string {
    96  	eps := obj.(*discovery.EndpointSlice)
    97  	if eps == nil {
    98  		return nil
    99  	}
   100  	var warnings []string
   101  	warnings = append(warnings, warnOnDeprecatedAddressType(eps.AddressType)...)
   102  	return warnings
   103  }
   104  
   105  // Canonicalize normalizes the object after validation.
   106  func (endpointSliceStrategy) Canonicalize(obj runtime.Object) {
   107  }
   108  
   109  // AllowCreateOnUpdate is false for EndpointSlice; this means POST is needed to create one.
   110  func (endpointSliceStrategy) AllowCreateOnUpdate() bool {
   111  	return false
   112  }
   113  
   114  // ValidateUpdate is the default update validation for an end user.
   115  func (endpointSliceStrategy) ValidateUpdate(ctx context.Context, new, old runtime.Object) field.ErrorList {
   116  	newEPS := new.(*discovery.EndpointSlice)
   117  	oldEPS := old.(*discovery.EndpointSlice)
   118  	return validation.ValidateEndpointSliceUpdate(newEPS, oldEPS)
   119  }
   120  
   121  // WarningsOnUpdate returns warnings for the given update.
   122  func (endpointSliceStrategy) WarningsOnUpdate(ctx context.Context, obj, old runtime.Object) []string {
   123  	return nil
   124  }
   125  
   126  // AllowUnconditionalUpdate is the default update policy for EndpointSlice objects.
   127  func (endpointSliceStrategy) AllowUnconditionalUpdate() bool {
   128  	return true
   129  }
   130  
   131  // dropDisabledConditionsOnCreate will drop any fields that are disabled.
   132  func dropDisabledFieldsOnCreate(endpointSlice *discovery.EndpointSlice) {
   133  	dropHints := !utilfeature.DefaultFeatureGate.Enabled(features.TopologyAwareHints)
   134  
   135  	if dropHints {
   136  		for i := range endpointSlice.Endpoints {
   137  			if dropHints {
   138  				endpointSlice.Endpoints[i].Hints = nil
   139  			}
   140  		}
   141  	}
   142  }
   143  
   144  // dropDisabledFieldsOnUpdate will drop any disable fields that have not already
   145  // been set on the EndpointSlice.
   146  func dropDisabledFieldsOnUpdate(oldEPS, newEPS *discovery.EndpointSlice) {
   147  	dropHints := !utilfeature.DefaultFeatureGate.Enabled(features.TopologyAwareHints)
   148  	if dropHints {
   149  		for _, ep := range oldEPS.Endpoints {
   150  			if ep.Hints != nil {
   151  				dropHints = false
   152  				break
   153  			}
   154  		}
   155  	}
   156  
   157  	if dropHints {
   158  		for i := range newEPS.Endpoints {
   159  			if dropHints {
   160  				newEPS.Endpoints[i].Hints = nil
   161  			}
   162  		}
   163  	}
   164  }
   165  
   166  // dropTopologyOnV1 on V1 request wipes the DeprecatedTopology field  and copies
   167  // the NodeName value into DeprecatedTopology
   168  func dropTopologyOnV1(ctx context.Context, oldEPS, newEPS *discovery.EndpointSlice) {
   169  	if info, ok := genericapirequest.RequestInfoFrom(ctx); ok {
   170  		requestGV := schema.GroupVersion{Group: info.APIGroup, Version: info.APIVersion}
   171  		if requestGV == discoveryv1beta1.SchemeGroupVersion {
   172  			return
   173  		}
   174  
   175  		// do not drop topology if endpoints have not been changed
   176  		if oldEPS != nil && apiequality.Semantic.DeepEqual(oldEPS.Endpoints, newEPS.Endpoints) {
   177  			return
   178  		}
   179  
   180  		// Only node names that exist in previous version of the EndpointSlice
   181  		// deprecatedTopology fields may be retained in new version of the
   182  		// EndpointSlice.
   183  		prevNodeNames := getDeprecatedTopologyNodeNames(oldEPS)
   184  
   185  		for i := range newEPS.Endpoints {
   186  			ep := &newEPS.Endpoints[i]
   187  
   188  			newTopologyNodeName, ok := ep.DeprecatedTopology[corev1.LabelHostname]
   189  			if ep.NodeName == nil && ok && prevNodeNames.Has(newTopologyNodeName) && len(apivalidation.ValidateNodeName(newTopologyNodeName, false)) == 0 {
   190  				// Copy the label previously used to store the node name into the nodeName field,
   191  				// in order to make partial updates preserve previous node info
   192  				ep.NodeName = &newTopologyNodeName
   193  			}
   194  			// Drop writes to this field via the v1 API as documented
   195  			ep.DeprecatedTopology = nil
   196  		}
   197  	}
   198  }
   199  
   200  // getDeprecatedTopologyNodeNames returns a set of node names present in
   201  // deprecatedTopology fields within the provided EndpointSlice.
   202  func getDeprecatedTopologyNodeNames(eps *discovery.EndpointSlice) sets.String {
   203  	if eps == nil {
   204  		return nil
   205  	}
   206  	var names sets.String
   207  	for _, ep := range eps.Endpoints {
   208  		if nodeName, ok := ep.DeprecatedTopology[corev1.LabelHostname]; ok && len(nodeName) > 0 {
   209  			if names == nil {
   210  				names = sets.NewString()
   211  			}
   212  			names.Insert(nodeName)
   213  		}
   214  	}
   215  	return names
   216  }
   217  
   218  // warnOnDeprecatedAddressType returns a warning for endpointslices with FQDN AddressType
   219  func warnOnDeprecatedAddressType(addressType discovery.AddressType) []string {
   220  	if addressType == discovery.AddressTypeFQDN {
   221  		return []string{fmt.Sprintf("%s: FQDN endpoints are deprecated", field.NewPath("spec").Child("addressType"))}
   222  	}
   223  	return nil
   224  }
   225
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