k8s.io/kubernetes@v1.31.0-alpha.0.0.20240520171757-56147500dadc/pkg/controlplane/apiserver/apis.go (about)

     1  /*
     2  Copyright 2023 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 apiserver
    18  
    19  import (
    20  	"fmt"
    21  
    22  	"k8s.io/apiserver/pkg/registry/generic"
    23  	genericapiserver "k8s.io/apiserver/pkg/server"
    24  	serverstorage "k8s.io/apiserver/pkg/server/storage"
    25  	"k8s.io/klog/v2"
    26  )
    27  
    28  // RESTStorageProvider is a factory type for REST storage.
    29  type RESTStorageProvider interface {
    30  	GroupName() string
    31  	NewRESTStorage(apiResourceConfigSource serverstorage.APIResourceConfigSource, restOptionsGetter generic.RESTOptionsGetter) (genericapiserver.APIGroupInfo, error)
    32  }
    33  
    34  // InstallAPIs will install the APIs for the restStorageProviders if they are enabled.
    35  func (s *Server) InstallAPIs(restStorageProviders ...RESTStorageProvider) error {
    36  	nonLegacy := []*genericapiserver.APIGroupInfo{}
    37  
    38  	// used later in the loop to filter the served resource by those that have expired.
    39  	resourceExpirationEvaluator, err := genericapiserver.NewResourceExpirationEvaluator(*s.GenericAPIServer.Version)
    40  	if err != nil {
    41  		return err
    42  	}
    43  
    44  	for _, restStorageBuilder := range restStorageProviders {
    45  		groupName := restStorageBuilder.GroupName()
    46  		apiGroupInfo, err := restStorageBuilder.NewRESTStorage(s.APIResourceConfigSource, s.RESTOptionsGetter)
    47  		if err != nil {
    48  			return fmt.Errorf("problem initializing API group %q: %w", groupName, err)
    49  		}
    50  		if len(apiGroupInfo.VersionedResourcesStorageMap) == 0 {
    51  			// If we have no storage for any resource configured, this API group is effectively disabled.
    52  			// This can happen when an entire API group, version, or development-stage (alpha, beta, GA) is disabled.
    53  			klog.Infof("API group %q is not enabled, skipping.", groupName)
    54  			continue
    55  		}
    56  
    57  		// Remove resources that serving kinds that are removed.
    58  		// We do this here so that we don't accidentally serve versions without resources or openapi information that for kinds we don't serve.
    59  		// This is a spot above the construction of individual storage handlers so that no sig accidentally forgets to check.
    60  		resourceExpirationEvaluator.RemoveDeletedKinds(groupName, apiGroupInfo.Scheme, apiGroupInfo.VersionedResourcesStorageMap)
    61  		if len(apiGroupInfo.VersionedResourcesStorageMap) == 0 {
    62  			klog.V(1).Infof("Removing API group %v because it is time to stop serving it because it has no versions per APILifecycle.", groupName)
    63  			continue
    64  		}
    65  
    66  		klog.V(1).Infof("Enabling API group %q.", groupName)
    67  
    68  		if postHookProvider, ok := restStorageBuilder.(genericapiserver.PostStartHookProvider); ok {
    69  			name, hook, err := postHookProvider.PostStartHook()
    70  			if err != nil {
    71  				return fmt.Errorf("error building PostStartHook: %w", err)
    72  			}
    73  			s.GenericAPIServer.AddPostStartHookOrDie(name, hook)
    74  		}
    75  
    76  		if len(groupName) == 0 {
    77  			// the legacy group for core APIs is special that it is installed into /api via this special install method.
    78  			if err := s.GenericAPIServer.InstallLegacyAPIGroup(genericapiserver.DefaultLegacyAPIPrefix, &apiGroupInfo); err != nil {
    79  				return fmt.Errorf("error in registering legacy API: %w", err)
    80  			}
    81  		} else {
    82  			// everything else goes to /apis
    83  			nonLegacy = append(nonLegacy, &apiGroupInfo)
    84  		}
    85  	}
    86  
    87  	if err := s.GenericAPIServer.InstallAPIGroups(nonLegacy...); err != nil {
    88  		return fmt.Errorf("error in registering group versions: %w", err)
    89  	}
    90  	return nil
    91  }