Matthias Andreas Benkard | 832a54e | 2019-01-29 09:27:38 +0100 | [diff] [blame^] | 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 | "sync" |
| 22 | |
| 23 | restful "github.com/emicklei/go-restful" |
| 24 | |
| 25 | metav1 "k8s.io/apimachinery/pkg/apis/meta/v1" |
| 26 | "k8s.io/apimachinery/pkg/runtime" |
| 27 | "k8s.io/apimachinery/pkg/runtime/schema" |
| 28 | utilnet "k8s.io/apimachinery/pkg/util/net" |
| 29 | "k8s.io/apiserver/pkg/endpoints/handlers/negotiation" |
| 30 | "k8s.io/apiserver/pkg/endpoints/handlers/responsewriters" |
| 31 | ) |
| 32 | |
| 33 | // GroupManager is an interface that allows dynamic mutation of the existing webservice to handle |
| 34 | // API groups being added or removed. |
| 35 | type GroupManager interface { |
| 36 | AddGroup(apiGroup metav1.APIGroup) |
| 37 | RemoveGroup(groupName string) |
| 38 | |
| 39 | WebService() *restful.WebService |
| 40 | } |
| 41 | |
| 42 | // rootAPIsHandler creates a webservice serving api group discovery. |
| 43 | // The list of APIGroups may change while the server is running because additional resources |
| 44 | // are registered or removed. It is not safe to cache the values. |
| 45 | type rootAPIsHandler struct { |
| 46 | // addresses is used to build cluster IPs for discovery. |
| 47 | addresses Addresses |
| 48 | |
| 49 | serializer runtime.NegotiatedSerializer |
| 50 | |
| 51 | // Map storing information about all groups to be exposed in discovery response. |
| 52 | // The map is from name to the group. |
| 53 | lock sync.RWMutex |
| 54 | apiGroups map[string]metav1.APIGroup |
| 55 | // apiGroupNames preserves insertion order |
| 56 | apiGroupNames []string |
| 57 | } |
| 58 | |
| 59 | func NewRootAPIsHandler(addresses Addresses, serializer runtime.NegotiatedSerializer) *rootAPIsHandler { |
| 60 | // Because in release 1.1, /apis returns response with empty APIVersion, we |
| 61 | // use stripVersionNegotiatedSerializer to keep the response backwards |
| 62 | // compatible. |
| 63 | serializer = stripVersionNegotiatedSerializer{serializer} |
| 64 | |
| 65 | return &rootAPIsHandler{ |
| 66 | addresses: addresses, |
| 67 | serializer: serializer, |
| 68 | apiGroups: map[string]metav1.APIGroup{}, |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | func (s *rootAPIsHandler) AddGroup(apiGroup metav1.APIGroup) { |
| 73 | s.lock.Lock() |
| 74 | defer s.lock.Unlock() |
| 75 | |
| 76 | _, alreadyExists := s.apiGroups[apiGroup.Name] |
| 77 | |
| 78 | s.apiGroups[apiGroup.Name] = apiGroup |
| 79 | if !alreadyExists { |
| 80 | s.apiGroupNames = append(s.apiGroupNames, apiGroup.Name) |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | func (s *rootAPIsHandler) RemoveGroup(groupName string) { |
| 85 | s.lock.Lock() |
| 86 | defer s.lock.Unlock() |
| 87 | |
| 88 | delete(s.apiGroups, groupName) |
| 89 | for i := range s.apiGroupNames { |
| 90 | if s.apiGroupNames[i] == groupName { |
| 91 | s.apiGroupNames = append(s.apiGroupNames[:i], s.apiGroupNames[i+1:]...) |
| 92 | break |
| 93 | } |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | func (s *rootAPIsHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) { |
| 98 | s.lock.RLock() |
| 99 | defer s.lock.RUnlock() |
| 100 | |
| 101 | orderedGroups := []metav1.APIGroup{} |
| 102 | for _, groupName := range s.apiGroupNames { |
| 103 | orderedGroups = append(orderedGroups, s.apiGroups[groupName]) |
| 104 | } |
| 105 | |
| 106 | clientIP := utilnet.GetClientIP(req) |
| 107 | serverCIDR := s.addresses.ServerAddressByClientCIDRs(clientIP) |
| 108 | groups := make([]metav1.APIGroup, len(orderedGroups)) |
| 109 | for i := range orderedGroups { |
| 110 | groups[i] = orderedGroups[i] |
| 111 | groups[i].ServerAddressByClientCIDRs = serverCIDR |
| 112 | } |
| 113 | |
| 114 | responsewriters.WriteObjectNegotiated(s.serializer, schema.GroupVersion{}, resp, req, http.StatusOK, &metav1.APIGroupList{Groups: groups}) |
| 115 | } |
| 116 | |
| 117 | func (s *rootAPIsHandler) restfulHandle(req *restful.Request, resp *restful.Response) { |
| 118 | s.ServeHTTP(resp.ResponseWriter, req.Request) |
| 119 | } |
| 120 | |
| 121 | // WebService returns a webservice serving api group discovery. |
| 122 | // Note: during the server runtime apiGroups might change. |
| 123 | func (s *rootAPIsHandler) WebService() *restful.WebService { |
| 124 | mediaTypes, _ := negotiation.MediaTypesForSerializer(s.serializer) |
| 125 | ws := new(restful.WebService) |
| 126 | ws.Path(APIGroupPrefix) |
| 127 | ws.Doc("get available API versions") |
| 128 | ws.Route(ws.GET("/").To(s.restfulHandle). |
| 129 | Doc("get available API versions"). |
| 130 | Operation("getAPIVersions"). |
| 131 | Produces(mediaTypes...). |
| 132 | Consumes(mediaTypes...). |
| 133 | Writes(metav1.APIGroupList{})) |
| 134 | return ws |
| 135 | } |