k8s.io/apiserver@v0.31.1/pkg/endpoints/discovery/version.go (about)

     1  /*
     2  Copyright 2017 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 discovery
    18  
    19  import (
    20  	"net/http"
    21  
    22  	restful "github.com/emicklei/go-restful/v3"
    23  
    24  	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    25  	"k8s.io/apimachinery/pkg/runtime"
    26  	"k8s.io/apimachinery/pkg/runtime/schema"
    27  	"k8s.io/apiserver/pkg/endpoints/handlers/negotiation"
    28  	"k8s.io/apiserver/pkg/endpoints/handlers/responsewriters"
    29  )
    30  
    31  type APIResourceLister interface {
    32  	ListAPIResources() []metav1.APIResource
    33  }
    34  
    35  type APIResourceListerFunc func() []metav1.APIResource
    36  
    37  func (f APIResourceListerFunc) ListAPIResources() []metav1.APIResource {
    38  	return f()
    39  }
    40  
    41  // APIVersionHandler creates a webservice serving the supported resources for the version
    42  // E.g., such a web service will be registered at /apis/extensions/v1beta1.
    43  type APIVersionHandler struct {
    44  	serializer runtime.NegotiatedSerializer
    45  
    46  	groupVersion      schema.GroupVersion
    47  	apiResourceLister APIResourceLister
    48  }
    49  
    50  func NewAPIVersionHandler(serializer runtime.NegotiatedSerializer, groupVersion schema.GroupVersion, apiResourceLister APIResourceLister) *APIVersionHandler {
    51  	if keepUnversioned(groupVersion.Group) {
    52  		// Because in release 1.1, /apis/extensions returns response with empty
    53  		// APIVersion, we use stripVersionNegotiatedSerializer to keep the
    54  		// response backwards compatible.
    55  		serializer = stripVersionNegotiatedSerializer{serializer}
    56  	}
    57  
    58  	return &APIVersionHandler{
    59  		serializer:        serializer,
    60  		groupVersion:      groupVersion,
    61  		apiResourceLister: apiResourceLister,
    62  	}
    63  }
    64  
    65  func (s *APIVersionHandler) AddToWebService(ws *restful.WebService) {
    66  	mediaTypes, _ := negotiation.MediaTypesForSerializer(s.serializer)
    67  	ws.Route(ws.GET("/").To(s.handle).
    68  		Doc("get available resources").
    69  		Operation("getAPIResources").
    70  		Produces(mediaTypes...).
    71  		Consumes(mediaTypes...).
    72  		Writes(metav1.APIResourceList{}))
    73  }
    74  
    75  // handle returns a handler which will return the api.VersionAndVersion of the group.
    76  func (s *APIVersionHandler) handle(req *restful.Request, resp *restful.Response) {
    77  	s.ServeHTTP(resp.ResponseWriter, req.Request)
    78  }
    79  
    80  func (s *APIVersionHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
    81  	responsewriters.WriteObjectNegotiated(s.serializer, negotiation.DefaultEndpointRestrictions, schema.GroupVersion{}, w, req, http.StatusOK,
    82  		&metav1.APIResourceList{GroupVersion: s.groupVersion.String(), APIResources: s.apiResourceLister.ListAPIResources()}, false)
    83  }