/
installer.go
282 lines (242 loc) · 10.1 KB
/
installer.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
/*
Copyright 2017 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package installer
import (
"fmt"
gpath "path"
"reflect"
"strings"
"time"
"github.com/emicklei/go-restful/v3"
"k8s.io/apimachinery/pkg/conversion"
"k8s.io/apimachinery/pkg/runtime/schema"
utilerrors "k8s.io/apimachinery/pkg/util/errors"
"k8s.io/apiserver/pkg/endpoints"
"k8s.io/apiserver/pkg/endpoints/discovery"
"k8s.io/apiserver/pkg/endpoints/handlers"
"k8s.io/apiserver/pkg/endpoints/handlers/negotiation"
"k8s.io/apiserver/pkg/registry/rest"
cm_handlers "sigs.k8s.io/custom-metrics-apiserver/pkg/apiserver/endpoints/handlers"
cm_rest "sigs.k8s.io/custom-metrics-apiserver/pkg/apiserver/registry/rest"
)
// NB: the contents of this file should mostly be a subset of the functionality
// in "k8s.io/apiserver/pkg/endpoints". It would be nice to eventual figure out
// a way to not have to recreate/copy a bunch of the structure from the normal API
// installer, so that this trivially tracks changes to the main installer.
// MetricsAPIGroupVersion is similar to "k8s.io/apiserver/pkg/endpoints".APIGroupVersion,
// except that it installs the metrics REST handlers, which use wildcard resources
// and subresources.
//
// This basically only serves the limitted use case required by the metrics API server --
// the only verb accepted is GET (and perhaps WATCH in the future).
type MetricsAPIGroupVersion struct {
DynamicStorage rest.Storage
*endpoints.APIGroupVersion
ResourceLister discovery.APIResourceLister
Handlers apiHandlers
}
type apiHandlers interface {
registerResourceHandlers(a *MetricsAPIInstaller, ws *restful.WebService) error
}
// InstallDynamicREST registers the dynamic REST handlers into a restful Container.
// It is expected that the provided path root prefix will serve all operations. Root MUST
// NOT end in a slash. It should mirror InstallREST in the plain APIGroupVersion.
func (g *MetricsAPIGroupVersion) InstallREST(container *restful.Container) error {
installer := g.newDynamicInstaller()
ws := installer.NewWebService()
registrationErrors := installer.Install(ws)
lister := g.ResourceLister
if lister == nil {
return fmt.Errorf("must provide a dynamic lister for dynamic API groups")
}
versionDiscoveryHandler := discovery.NewAPIVersionHandler(g.Serializer, g.GroupVersion, lister)
versionDiscoveryHandler.AddToWebService(ws)
container.Add(ws)
return utilerrors.NewAggregate(registrationErrors)
}
// newDynamicInstaller is a helper to create the installer. It mirrors
// newInstaller in APIGroupVersion.
func (g *MetricsAPIGroupVersion) newDynamicInstaller() *MetricsAPIInstaller {
prefix := gpath.Join(g.Root, g.GroupVersion.Group, g.GroupVersion.Version)
installer := &MetricsAPIInstaller{
group: g,
prefix: prefix,
minRequestTimeout: g.MinRequestTimeout,
handlers: g.Handlers,
}
return installer
}
// MetricsAPIInstaller is a specialized API installer for the metrics API.
// It is intended to be fully compliant with the Kubernetes API server conventions,
// but serves wildcard resource/subresource routes instead of hard-coded resources
// and subresources.
type MetricsAPIInstaller struct {
group *MetricsAPIGroupVersion
prefix string // Path prefix where API resources are to be registered.
minRequestTimeout time.Duration
handlers apiHandlers
// TODO: do we want to embed a normal API installer here so we can serve normal
// endpoints side by side with dynamic ones (from the same API group)?
}
// Install installs handlers for External Metrics API resources.
func (a *MetricsAPIInstaller) Install(ws *restful.WebService) (errors []error) {
errors = make([]error, 0)
err := a.handlers.registerResourceHandlers(a, ws)
if err != nil {
errors = append(errors, fmt.Errorf("error in registering custom metrics resource: %v", err))
}
return errors
}
// NewWebService creates a new restful webservice with the api installer's prefix and version.
func (a *MetricsAPIInstaller) NewWebService() *restful.WebService {
ws := new(restful.WebService)
ws.Path(a.prefix)
// a.prefix contains "prefix/group/version"
ws.Doc("API at " + a.prefix)
// Backwards compatibility, we accepted objects with empty content-type at V1.
// If we stop using go-restful, we can default empty content-type to application/json on an
// endpoint by endpoint basis
ws.Consumes("*/*")
mediaTypes, streamMediaTypes := negotiation.MediaTypesForSerializer(a.group.Serializer)
ws.Produces(append(mediaTypes, streamMediaTypes...)...)
ws.ApiVersion(a.group.GroupVersion.String())
return ws
}
// This magic incantation returns *ptrToObject for an arbitrary pointer
func indirectArbitraryPointer(ptrToObject interface{}) interface{} {
return reflect.Indirect(reflect.ValueOf(ptrToObject)).Interface()
}
// getResourceKind returns the external group version kind registered for the given storage object.
func (a *MetricsAPIInstaller) getResourceKind(storage rest.Storage) (schema.GroupVersionKind, error) {
object := storage.New()
fqKinds, _, err := a.group.Typer.ObjectKinds(object)
if err != nil {
return schema.GroupVersionKind{}, err
}
// a given go type can have multiple potential fully qualified kinds. Find the one that corresponds with the group
// we're trying to register here
fqKindToRegister := schema.GroupVersionKind{}
for _, fqKind := range fqKinds {
if fqKind.Group == a.group.GroupVersion.Group {
fqKindToRegister = a.group.GroupVersion.WithKind(fqKind.Kind)
break
}
// TODO: keep rid of extensions api group dependency here
// This keeps it doing what it was doing before, but it doesn't feel right.
if fqKind.Group == "extensions" && fqKind.Kind == "ThirdPartyResourceData" {
fqKindToRegister = a.group.GroupVersion.WithKind(fqKind.Kind)
}
}
if fqKindToRegister.Empty() {
return schema.GroupVersionKind{}, fmt.Errorf("unable to locate fully qualified kind for %v: found %v when registering for %v", reflect.TypeOf(object), fqKinds, a.group.GroupVersion)
}
return fqKindToRegister, nil
}
func addParams(route *restful.RouteBuilder, params []*restful.Parameter) {
for _, param := range params {
route.Param(param)
}
}
// addObjectParams converts a runtime.Object into a set of go-restful Param() definitions on the route.
// The object must be a pointer to a struct; only fields at the top level of the struct that are not
// themselves interfaces or structs are used; only fields with a json tag that is non empty (the standard
// Go JSON behavior for omitting a field) become query parameters. The name of the query parameter is
// the JSON field name. If a description struct tag is set on the field, that description is used on the
// query parameter. In essence, it converts a standard JSON top level object into a query param schema.
func addObjectParams(ws *restful.WebService, route *restful.RouteBuilder, obj interface{}) error {
sv, err := conversion.EnforcePtr(obj)
if err != nil {
return err
}
st := sv.Type()
if st.Kind() == reflect.Struct {
for i := 0; i < st.NumField(); i++ {
name := st.Field(i).Name
sf, ok := st.FieldByName(name)
if !ok {
continue
}
switch sf.Type.Kind() {
case reflect.Interface, reflect.Struct:
case reflect.Ptr:
// TODO: This is a hack to let metav1.Time through. This needs to be fixed in a more generic way eventually. bug #36191
if (sf.Type.Elem().Kind() == reflect.Interface || sf.Type.Elem().Kind() == reflect.Struct) && strings.TrimPrefix(sf.Type.String(), "*") != "metav1.Time" {
continue
}
fallthrough
default:
jsonTag := sf.Tag.Get("json")
if len(jsonTag) == 0 {
continue
}
jsonName := strings.SplitN(jsonTag, ",", 2)[0]
if len(jsonName) == 0 {
continue
}
var desc string
if docable, ok := obj.(documentable); ok {
desc = docable.SwaggerDoc()[jsonName]
}
if route.ParameterNamed(jsonName) == nil {
route.Param(ws.QueryParameter(jsonName, desc).DataType(typeToJSON(sf.Type.String())))
}
}
}
}
return nil
}
// TODO: this is incomplete, expand as needed.
// Convert the name of a golang type to the name of a JSON type
func typeToJSON(typeName string) string {
switch typeName {
case "bool", "*bool":
return "boolean"
case "uint8", "*uint8", "int", "*int", "int32", "*int32", "int64", "*int64", "uint32", "*uint32", "uint64", "*uint64":
return "integer"
case "float64", "*float64", "float32", "*float32":
return "number"
case "metav1.Time", "*metav1.Time":
return "string"
case "byte", "*byte":
return "string"
case "v1.DeletionPropagation", "*v1.DeletionPropagation", "v1.ResourceVersionMatch":
return "string"
// TODO: Fix these when go-restful supports a way to specify an array query param:
// https://github.com/emicklei/go-restful/issues/225
case "[]string", "[]*string":
return "string"
case "[]int32", "[]*int32":
return "integer"
default:
return typeName
}
}
// An interface to see if an object supports swagger documentation as a method
type documentable interface {
SwaggerDoc() map[string]string
}
// MetricsNaming is similar to handlers.ContextBasedNaming, except that it handles
// polymorphism over subresources.
type MetricsNaming struct {
handlers.ContextBasedNaming
}
func restfulListResource(r rest.Lister, rw rest.Watcher, scope handlers.RequestScope, forceWatch bool, minRequestTimeout time.Duration) restful.RouteFunction {
return func(req *restful.Request, res *restful.Response) {
handlers.ListResource(r, rw, &scope, forceWatch, minRequestTimeout)(res.ResponseWriter, req.Request)
}
}
func restfulListResourceWithOptions(r cm_rest.ListerWithOptions, scope handlers.RequestScope) restful.RouteFunction {
return func(req *restful.Request, res *restful.Response) {
cm_handlers.ListResourceWithOptions(r, scope)(res.ResponseWriter, req.Request)
}
}