-
Notifications
You must be signed in to change notification settings - Fork 100
/
reference.go
417 lines (360 loc) · 13.1 KB
/
reference.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
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
/*
Copyright 2019 The Crossplane 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 reference contains utilities for working with cross-resource
// references.
package reference
import (
"context"
"strconv"
kerrors "k8s.io/apimachinery/pkg/api/errors"
"k8s.io/apimachinery/pkg/types"
"sigs.k8s.io/controller-runtime/pkg/client"
xpv1 "github.com/crossplane/crossplane-runtime/apis/common/v1"
"github.com/crossplane/crossplane-runtime/pkg/errors"
"github.com/crossplane/crossplane-runtime/pkg/meta"
"github.com/crossplane/crossplane-runtime/pkg/resource"
)
// Error strings.
const (
errGetManaged = "cannot get referenced resource"
errListManaged = "cannot list resources that match selector"
errNoMatches = "no resources matched selector"
errNoValue = "referenced field was empty (referenced resource may not yet be ready)"
)
// NOTE(negz): There are many equivalents of FromPtrValue and ToPtrValue
// throughout the Crossplane codebase. We duplicate them here to reduce the
// number of packages our API types have to import to support references.
// FromPtrValue adapts a string pointer field for use as a CurrentValue.
func FromPtrValue(v *string) string {
if v == nil {
return ""
}
return *v
}
// FromFloatPtrValue adapts a float pointer field for use as a CurrentValue.
func FromFloatPtrValue(v *float64) string {
if v == nil {
return ""
}
return strconv.FormatFloat(*v, 'f', 0, 64)
}
// FromIntPtrValue adapts an int pointer field for use as a CurrentValue.
func FromIntPtrValue(v *int64) string {
if v == nil {
return ""
}
return strconv.FormatInt(*v, 10)
}
// ToPtrValue adapts a ResolvedValue for use as a string pointer field.
func ToPtrValue(v string) *string {
if v == "" {
return nil
}
return &v
}
// ToFloatPtrValue adapts a ResolvedValue for use as a float64 pointer field.
func ToFloatPtrValue(v string) *float64 {
if v == "" {
return nil
}
vParsed, err := strconv.ParseFloat(v, 64)
if err != nil {
return nil
}
return &vParsed
}
// ToIntPtrValue adapts a ResolvedValue for use as an int pointer field.
func ToIntPtrValue(v string) *int64 {
if v == "" {
return nil
}
vParsed, err := strconv.ParseInt(v, 10, 64)
if err != nil {
return nil
}
return &vParsed
}
// FromPtrValues adapts a slice of string pointer fields for use as CurrentValues.
// NOTE: Do not use this utility function unless you have to.
// Using pointer slices does not adhere to our current API practices.
// The current use case is where generated code creates reference-able fields in a provider which are
// string pointers and need to be resolved as part of `ResolveMultiple`.
func FromPtrValues(v []*string) []string {
res := make([]string, len(v))
for i := range len(v) {
res[i] = FromPtrValue(v[i])
}
return res
}
// FromFloatPtrValues adapts a slice of float64 pointer fields for use as CurrentValues.
func FromFloatPtrValues(v []*float64) []string {
res := make([]string, len(v))
for i := range len(v) {
res[i] = FromFloatPtrValue(v[i])
}
return res
}
// FromIntPtrValues adapts a slice of int64 pointer fields for use as CurrentValues.
func FromIntPtrValues(v []*int64) []string {
res := make([]string, len(v))
for i := range len(v) {
res[i] = FromIntPtrValue(v[i])
}
return res
}
// ToPtrValues adapts ResolvedValues for use as a slice of string pointer fields.
// NOTE: Do not use this utility function unless you have to.
// Using pointer slices does not adhere to our current API practices.
// The current use case is where generated code creates reference-able fields in a provider which are
// string pointers and need to be resolved as part of `ResolveMultiple`.
func ToPtrValues(v []string) []*string {
res := make([]*string, len(v))
for i := range len(v) {
res[i] = ToPtrValue(v[i])
}
return res
}
// ToFloatPtrValues adapts ResolvedValues for use as a slice of float64 pointer fields.
func ToFloatPtrValues(v []string) []*float64 {
res := make([]*float64, len(v))
for i := range len(v) {
res[i] = ToFloatPtrValue(v[i])
}
return res
}
// ToIntPtrValues adapts ResolvedValues for use as a slice of int64 pointer fields.
func ToIntPtrValues(v []string) []*int64 {
res := make([]*int64, len(v))
for i := range len(v) {
res[i] = ToIntPtrValue(v[i])
}
return res
}
// To indicates the kind of managed resource a reference is to.
type To struct {
Managed resource.Managed
List resource.ManagedList
}
// An ExtractValueFn specifies how to extract a value from the resolved managed
// resource.
type ExtractValueFn func(resource.Managed) string
// ExternalName extracts the resolved managed resource's external name from its
// external name annotation.
func ExternalName() ExtractValueFn {
return func(mg resource.Managed) string {
return meta.GetExternalName(mg)
}
}
// A ResolutionRequest requests that a reference to a particular kind of
// managed resource be resolved.
type ResolutionRequest struct {
CurrentValue string
Reference *xpv1.Reference
Selector *xpv1.Selector
To To
Extract ExtractValueFn
}
// IsNoOp returns true if the supplied ResolutionRequest cannot or should not be
// processed.
func (rr *ResolutionRequest) IsNoOp() bool {
isAlways := false
if rr.Selector != nil {
if rr.Selector.Policy.IsResolvePolicyAlways() {
rr.Reference = nil
isAlways = true
}
} else if rr.Reference != nil {
if rr.Reference.Policy.IsResolvePolicyAlways() {
isAlways = true
}
}
// We don't resolve values that are already set (if reference resolution policy
// is not set to Always); we effectively cache resolved values. The CR author
// can invalidate the cache and trigger a new resolution by explicitly clearing
// the resolved value.
if rr.CurrentValue != "" && !isAlways {
return true
}
// We can't resolve anything if neither a reference nor a selector were
// provided.
return rr.Reference == nil && rr.Selector == nil
}
// A ResolutionResponse returns the result of a reference resolution. The
// returned values are always safe to set if resolution was successful.
type ResolutionResponse struct {
ResolvedValue string
ResolvedReference *xpv1.Reference
}
// Validate this ResolutionResponse.
func (rr ResolutionResponse) Validate() error {
if rr.ResolvedValue == "" {
return errors.New(errNoValue)
}
return nil
}
// A MultiResolutionRequest requests that several references to a particular
// kind of managed resource be resolved.
type MultiResolutionRequest struct {
CurrentValues []string
References []xpv1.Reference
Selector *xpv1.Selector
To To
Extract ExtractValueFn
}
// IsNoOp returns true if the supplied MultiResolutionRequest cannot or should
// not be processed.
func (rr *MultiResolutionRequest) IsNoOp() bool {
isAlways := false
if rr.Selector != nil {
if rr.Selector.Policy.IsResolvePolicyAlways() {
rr.References = nil
isAlways = true
}
} else {
for _, r := range rr.References {
if r.Policy.IsResolvePolicyAlways() {
isAlways = true
break
}
}
}
// We don't resolve values that are already set (if reference resolution policy
// is not set to Always); we effectively cache resolved values. The CR author
// can invalidate the cache and trigger a new resolution by explicitly clearing
// the resolved values. This is a little unintuitive for the APIMultiResolver
// but mimics the UX of the APIResolver and simplifies the overall mental model.
if len(rr.CurrentValues) > 0 && !isAlways {
return true
}
// We can't resolve anything if neither a reference nor a selector were
// provided.
return len(rr.References) == 0 && rr.Selector == nil
}
// A MultiResolutionResponse returns the result of several reference
// resolutions. The returned values are always safe to set if resolution was
// successful.
type MultiResolutionResponse struct {
ResolvedValues []string
ResolvedReferences []xpv1.Reference
}
// Validate this MultiResolutionResponse.
func (rr MultiResolutionResponse) Validate() error {
if len(rr.ResolvedValues) == 0 {
return errors.New(errNoMatches)
}
for i, v := range rr.ResolvedValues {
if v == "" {
return getResolutionError(rr.ResolvedReferences[i].Policy, errors.New(errNoValue))
}
}
return nil
}
// An APIResolver selects and resolves references to managed resources in the
// Kubernetes API server.
type APIResolver struct {
client client.Reader
from resource.Managed
}
// NewAPIResolver returns a Resolver that selects and resolves references from
// the supplied managed resource to other managed resources in the Kubernetes
// API server.
func NewAPIResolver(c client.Reader, from resource.Managed) *APIResolver {
return &APIResolver{client: c, from: from}
}
// Resolve the supplied ResolutionRequest. The returned ResolutionResponse
// always contains valid values unless an error was returned.
func (r *APIResolver) Resolve(ctx context.Context, req ResolutionRequest) (ResolutionResponse, error) {
// Return early if from is being deleted, or the request is a no-op.
if meta.WasDeleted(r.from) || req.IsNoOp() {
return ResolutionResponse{ResolvedValue: req.CurrentValue, ResolvedReference: req.Reference}, nil
}
// The reference is already set - resolve it.
if req.Reference != nil {
if err := r.client.Get(ctx, types.NamespacedName{Name: req.Reference.Name}, req.To.Managed); err != nil {
if kerrors.IsNotFound(err) {
return ResolutionResponse{}, getResolutionError(req.Reference.Policy, errors.Wrap(err, errGetManaged))
}
return ResolutionResponse{}, errors.Wrap(err, errGetManaged)
}
rsp := ResolutionResponse{ResolvedValue: req.Extract(req.To.Managed), ResolvedReference: req.Reference}
return rsp, getResolutionError(req.Reference.Policy, rsp.Validate())
}
// The reference was not set, but a selector was. Select a reference.
if err := r.client.List(ctx, req.To.List, client.MatchingLabels(req.Selector.MatchLabels)); err != nil {
return ResolutionResponse{}, errors.Wrap(err, errListManaged)
}
for _, to := range req.To.List.GetItems() {
if ControllersMustMatch(req.Selector) && !meta.HaveSameController(r.from, to) {
continue
}
rsp := ResolutionResponse{ResolvedValue: req.Extract(to), ResolvedReference: &xpv1.Reference{Name: to.GetName()}}
return rsp, getResolutionError(req.Selector.Policy, rsp.Validate())
}
// We couldn't resolve anything.
return ResolutionResponse{}, getResolutionError(req.Selector.Policy, errors.New(errNoMatches))
}
// ResolveMultiple resolves the supplied MultiResolutionRequest. The returned
// MultiResolutionResponse always contains valid values unless an error was
// returned.
func (r *APIResolver) ResolveMultiple(ctx context.Context, req MultiResolutionRequest) (MultiResolutionResponse, error) { //nolint: gocyclo // Only at 11.
// Return early if from is being deleted, or the request is a no-op.
if meta.WasDeleted(r.from) || req.IsNoOp() {
return MultiResolutionResponse{ResolvedValues: req.CurrentValues, ResolvedReferences: req.References}, nil
}
// The references are already set - resolve them.
if len(req.References) > 0 {
vals := make([]string, len(req.References))
for i := range req.References {
if err := r.client.Get(ctx, types.NamespacedName{Name: req.References[i].Name}, req.To.Managed); err != nil {
if kerrors.IsNotFound(err) {
return MultiResolutionResponse{}, getResolutionError(req.References[i].Policy, errors.Wrap(err, errGetManaged))
}
return MultiResolutionResponse{}, errors.Wrap(err, errGetManaged)
}
vals[i] = req.Extract(req.To.Managed)
}
rsp := MultiResolutionResponse{ResolvedValues: vals, ResolvedReferences: req.References}
return rsp, rsp.Validate()
}
// No references were set, but a selector was. Select and resolve references.
if err := r.client.List(ctx, req.To.List, client.MatchingLabels(req.Selector.MatchLabels)); err != nil {
return MultiResolutionResponse{}, errors.Wrap(err, errListManaged)
}
items := req.To.List.GetItems()
refs := make([]xpv1.Reference, 0, len(items))
vals := make([]string, 0, len(items))
for _, to := range req.To.List.GetItems() {
if ControllersMustMatch(req.Selector) && !meta.HaveSameController(r.from, to) {
continue
}
vals = append(vals, req.Extract(to))
refs = append(refs, xpv1.Reference{Name: to.GetName()})
}
rsp := MultiResolutionResponse{ResolvedValues: vals, ResolvedReferences: refs}
return rsp, getResolutionError(req.Selector.Policy, rsp.Validate())
}
func getResolutionError(p *xpv1.Policy, err error) error {
if !p.IsResolutionPolicyOptional() {
return err
}
return nil
}
// ControllersMustMatch returns true if the supplied Selector requires that a
// reference be to a managed resource whose controller reference matches the
// referencing resource.
func ControllersMustMatch(s *xpv1.Selector) bool {
if s == nil {
return false
}
return s.MatchControllerRef != nil && *s.MatchControllerRef
}