/
controller_reconcile.go
551 lines (473 loc) · 18.6 KB
/
controller_reconcile.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
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
/*
Copyright 2022 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 validatingadmissionpolicy
import (
"context"
"fmt"
"sync"
"time"
v1 "k8s.io/api/admissionregistration/v1"
"k8s.io/api/admissionregistration/v1beta1"
corev1 "k8s.io/api/core/v1"
apiequality "k8s.io/apimachinery/pkg/api/equality"
"k8s.io/apimachinery/pkg/api/meta"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
"k8s.io/apimachinery/pkg/util/sets"
celmetrics "k8s.io/apiserver/pkg/admission/cel"
"k8s.io/apiserver/pkg/admission/plugin/cel"
"k8s.io/apiserver/pkg/admission/plugin/validatingadmissionpolicy/internal/generic"
"k8s.io/apiserver/pkg/admission/plugin/webhook/matchconditions"
"k8s.io/apiserver/pkg/cel/environment"
"k8s.io/client-go/dynamic"
"k8s.io/client-go/dynamic/dynamicinformer"
"k8s.io/client-go/informers"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/cache"
)
type policyController struct {
once sync.Once
context context.Context
dynamicClient dynamic.Interface
informerFactory informers.SharedInformerFactory
restMapper meta.RESTMapper
policyDefinitionsController generic.Controller[*v1beta1.ValidatingAdmissionPolicy]
policyBindingController generic.Controller[*v1beta1.ValidatingAdmissionPolicyBinding]
// Provided to the policy's Compile function as an injected dependency to
// assist with compiling its expressions to CEL
// pass nil to create filter compiler in demand
filterCompiler cel.FilterCompiler
matcher Matcher
newValidator
client kubernetes.Interface
// Lock which protects
// All Below fields
// All above fields should be assumed constant
mutex sync.RWMutex
cachedPolicies []policyData
// controller and metadata
paramsCRDControllers map[v1beta1.ParamKind]*paramInfo
// Index for each definition namespace/name, contains all binding
// namespace/names known to exist for that definition
definitionInfo map[namespacedName]*definitionInfo
// Index for each bindings namespace/name. Contains compiled templates
// for the binding depending on the policy/param combination.
bindingInfos map[namespacedName]*bindingInfo
// Map from namespace/name of a definition to a set of namespace/name
// of bindings which depend on it.
// All keys must have at least one dependent binding
// All binding names MUST exist as a key bindingInfos
definitionsToBindings map[namespacedName]sets.Set[namespacedName]
}
type newValidator func(validationFilter cel.Filter, celMatcher matchconditions.Matcher, auditAnnotationFilter, messageFilter cel.Filter, failurePolicy *v1.FailurePolicyType) Validator
func newPolicyController(
restMapper meta.RESTMapper,
client kubernetes.Interface,
dynamicClient dynamic.Interface,
informerFactory informers.SharedInformerFactory,
filterCompiler cel.FilterCompiler,
matcher Matcher,
policiesInformer generic.Informer[*v1beta1.ValidatingAdmissionPolicy],
bindingsInformer generic.Informer[*v1beta1.ValidatingAdmissionPolicyBinding],
) *policyController {
res := &policyController{}
*res = policyController{
filterCompiler: filterCompiler,
definitionInfo: make(map[namespacedName]*definitionInfo),
bindingInfos: make(map[namespacedName]*bindingInfo),
paramsCRDControllers: make(map[v1beta1.ParamKind]*paramInfo),
definitionsToBindings: make(map[namespacedName]sets.Set[namespacedName]),
matcher: matcher,
newValidator: NewValidator,
policyDefinitionsController: generic.NewController(
policiesInformer,
res.reconcilePolicyDefinition,
generic.ControllerOptions{
Workers: 1,
Name: "cel-policy-definitions",
},
),
policyBindingController: generic.NewController(
bindingsInformer,
res.reconcilePolicyBinding,
generic.ControllerOptions{
Workers: 1,
Name: "cel-policy-bindings",
},
),
restMapper: restMapper,
dynamicClient: dynamicClient,
informerFactory: informerFactory,
client: client,
}
return res
}
func (c *policyController) Run(ctx context.Context) {
// Only support being run once
c.once.Do(func() {
c.context = ctx
wg := sync.WaitGroup{}
wg.Add(1)
go func() {
defer wg.Done()
c.policyDefinitionsController.Run(ctx)
}()
wg.Add(1)
go func() {
defer wg.Done()
c.policyBindingController.Run(ctx)
}()
<-ctx.Done()
wg.Wait()
})
}
func (c *policyController) HasSynced() bool {
return c.policyDefinitionsController.HasSynced() && c.policyBindingController.HasSynced()
}
func (c *policyController) reconcilePolicyDefinition(namespace, name string, definition *v1beta1.ValidatingAdmissionPolicy) error {
c.mutex.Lock()
defer c.mutex.Unlock()
err := c.reconcilePolicyDefinitionSpec(namespace, name, definition)
return err
}
func (c *policyController) reconcilePolicyDefinitionSpec(namespace, name string, definition *v1beta1.ValidatingAdmissionPolicy) error {
c.cachedPolicies = nil // invalidate cachedPolicies
// Namespace for policydefinition is empty.
nn := getNamespaceName(namespace, name)
info, ok := c.definitionInfo[nn]
if !ok {
info = &definitionInfo{}
c.definitionInfo[nn] = info
// TODO(DangerOnTheRanger): add support for "warn" being a valid enforcementAction
celmetrics.Metrics.ObserveDefinition(context.TODO(), "active", "deny")
}
// Skip reconcile if the spec of the definition is unchanged and had a
// successful previous sync
if info.configurationError == nil && info.lastReconciledValue != nil && definition != nil &&
apiequality.Semantic.DeepEqual(info.lastReconciledValue.Spec, definition.Spec) {
return nil
}
var paramSource *v1beta1.ParamKind
if definition != nil {
paramSource = definition.Spec.ParamKind
}
// If param source has changed, remove definition as dependent of old params
// If there are no more dependents of old param, stop and clean up controller
if info.lastReconciledValue != nil && info.lastReconciledValue.Spec.ParamKind != nil {
oldParamSource := *info.lastReconciledValue.Spec.ParamKind
// If we are:
// - switching from having a param to not having a param (includes deletion)
// - or from having a param to a different one
// we remove dependency on the controller.
if paramSource == nil || *paramSource != oldParamSource {
if oldParamInfo, ok := c.paramsCRDControllers[oldParamSource]; ok {
oldParamInfo.dependentDefinitions.Delete(nn)
if len(oldParamInfo.dependentDefinitions) == 0 {
oldParamInfo.stop()
delete(c.paramsCRDControllers, oldParamSource)
}
}
}
}
// Reset all previously compiled evaluators in case something relevant in
// definition has changed.
for key := range c.definitionsToBindings[nn] {
bindingInfo := c.bindingInfos[key]
bindingInfo.validator = nil
c.bindingInfos[key] = bindingInfo
}
if definition == nil {
delete(c.definitionInfo, nn)
return nil
}
// Update definition info
info.lastReconciledValue = definition
info.configurationError = nil
if paramSource == nil {
// Skip setting up controller for empty param type
return nil
}
// find GVR for params
// Parse param source into a GVK
paramSourceGV, err := schema.ParseGroupVersion(paramSource.APIVersion)
if err != nil {
// Failed to resolve. Return error so we retry again (rate limited)
// Save a record of this definition with an evaluator that unconditionally
info.configurationError = fmt.Errorf("failed to parse apiVersion of paramKind '%v' with error: %w", paramSource.String(), err)
// Return nil, since this error cannot be resolved by waiting more time
return nil
}
paramsGVR, err := c.restMapper.RESTMapping(schema.GroupKind{
Group: paramSourceGV.Group,
Kind: paramSource.Kind,
}, paramSourceGV.Version)
if err != nil {
// Failed to resolve. Return error so we retry again (rate limited)
// Save a record of this definition with an evaluator that unconditionally
//
info.configurationError = fmt.Errorf("failed to find resource referenced by paramKind: '%v'", paramSourceGV.WithKind(paramSource.Kind))
return info.configurationError
}
paramInfo := c.ensureParamInfo(paramSource, paramsGVR)
paramInfo.dependentDefinitions.Insert(nn)
return nil
}
// Ensures that there is an informer started for the given GVK to be used as a
// param
func (c *policyController) ensureParamInfo(paramSource *v1beta1.ParamKind, mapping *meta.RESTMapping) *paramInfo {
if info, ok := c.paramsCRDControllers[*paramSource]; ok {
return info
}
// We are not watching this param. Start an informer for it.
instanceContext, instanceCancel := context.WithCancel(c.context)
var informer cache.SharedIndexInformer
// Try to see if our provided informer factory has an informer for this type.
// We assume the informer is already started, and starts all types associated
// with it.
if genericInformer, err := c.informerFactory.ForResource(mapping.Resource); err == nil {
informer = genericInformer.Informer()
// Ensure the informer is started
// Use policyController's context rather than the instance context.
// PolicyController context is expected to last until app shutdown
// This is due to behavior of informerFactory which would cause the
// informer to stop running once the context is cancelled, and
// never started again.
c.informerFactory.Start(c.context.Done())
} else {
// Dynamic JSON informer fallback.
// Cannot use shared dynamic informer since it would be impossible
// to clean CRD informers properly with multiple dependents
// (cannot start ahead of time, and cannot track dependencies via stopCh)
informer = dynamicinformer.NewFilteredDynamicInformer(
c.dynamicClient,
mapping.Resource,
corev1.NamespaceAll,
// Use same interval as is used for k8s typed sharedInformerFactory
// https://github.com/kubernetes/kubernetes/blob/7e0923899fed622efbc8679cca6b000d43633e38/cmd/kube-apiserver/app/server.go#L430
10*time.Minute,
cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc},
nil,
).Informer()
go informer.Run(instanceContext.Done())
}
controller := generic.NewController(
generic.NewInformer[runtime.Object](informer),
c.reconcileParams,
generic.ControllerOptions{
Workers: 1,
Name: paramSource.String() + "-controller",
},
)
ret := ¶mInfo{
controller: controller,
stop: instanceCancel,
scope: mapping.Scope,
dependentDefinitions: sets.New[namespacedName](),
}
c.paramsCRDControllers[*paramSource] = ret
go controller.Run(instanceContext)
return ret
}
func (c *policyController) reconcilePolicyBinding(namespace, name string, binding *v1beta1.ValidatingAdmissionPolicyBinding) error {
c.mutex.Lock()
defer c.mutex.Unlock()
c.cachedPolicies = nil // invalidate cachedPolicies
// Namespace for PolicyBinding is empty. In the future a namespaced binding
// may be added
// https://github.com/kubernetes/enhancements/blob/bf5c3c81ea2081d60c1dc7c832faa98479e06209/keps/sig-api-machinery/3488-cel-admission-control/README.md?plain=1#L1042
nn := getNamespaceName(namespace, name)
info, ok := c.bindingInfos[nn]
if !ok {
info = &bindingInfo{}
c.bindingInfos[nn] = info
}
// Skip if the spec of the binding is unchanged.
if info.lastReconciledValue != nil && binding != nil &&
apiequality.Semantic.DeepEqual(info.lastReconciledValue.Spec, binding.Spec) {
return nil
}
var oldNamespacedDefinitionName namespacedName
if info.lastReconciledValue != nil {
// All validating policies are cluster-scoped so have empty namespace
oldNamespacedDefinitionName = getNamespaceName("", info.lastReconciledValue.Spec.PolicyName)
}
var namespacedDefinitionName namespacedName
if binding != nil {
// All validating policies are cluster-scoped so have empty namespace
namespacedDefinitionName = getNamespaceName("", binding.Spec.PolicyName)
}
// Remove record of binding from old definition if the referred policy
// has changed
if oldNamespacedDefinitionName != namespacedDefinitionName {
if dependentBindings, ok := c.definitionsToBindings[oldNamespacedDefinitionName]; ok {
dependentBindings.Delete(nn)
// if there are no more dependent bindings, remove knowledge of the
// definition altogether
if len(dependentBindings) == 0 {
delete(c.definitionsToBindings, oldNamespacedDefinitionName)
}
}
}
if binding == nil {
delete(c.bindingInfos, nn)
return nil
}
// Add record of binding to new definition
if dependentBindings, ok := c.definitionsToBindings[namespacedDefinitionName]; ok {
dependentBindings.Insert(nn)
} else {
c.definitionsToBindings[namespacedDefinitionName] = sets.New(nn)
}
// Remove compiled template for old binding
info.validator = nil
info.lastReconciledValue = binding
return nil
}
func (c *policyController) reconcileParams(namespace, name string, params runtime.Object) error {
// Do nothing.
// When we add informational type checking we will need to compile in the
// reconcile loops instead of lazily so we can add compiler errors / type
// checker errors to the status of the resources.
return nil
}
// Fetches the latest set of policy data or recalculates it if it has changed
// since it was last fetched
func (c *policyController) latestPolicyData() []policyData {
existing := func() []policyData {
c.mutex.RLock()
defer c.mutex.RUnlock()
return c.cachedPolicies
}()
if existing != nil {
return existing
}
c.mutex.Lock()
defer c.mutex.Unlock()
var res []policyData
for definitionNN, definitionInfo := range c.definitionInfo {
var bindingInfos []bindingInfo
for bindingNN := range c.definitionsToBindings[definitionNN] {
bindingInfo := c.bindingInfos[bindingNN]
if bindingInfo.validator == nil && definitionInfo.configurationError == nil {
hasParam := false
if definitionInfo.lastReconciledValue.Spec.ParamKind != nil {
hasParam = true
}
optionalVars := cel.OptionalVariableDeclarations{HasParams: hasParam, HasAuthorizer: true}
expressionOptionalVars := cel.OptionalVariableDeclarations{HasParams: hasParam, HasAuthorizer: false}
failurePolicy := convertv1beta1FailurePolicyTypeTov1FailurePolicyType(definitionInfo.lastReconciledValue.Spec.FailurePolicy)
var matcher matchconditions.Matcher = nil
matchConditions := definitionInfo.lastReconciledValue.Spec.MatchConditions
filterCompiler := c.filterCompiler
if filterCompiler == nil {
compositedCompiler, err := cel.NewCompositedCompiler(environment.MustBaseEnvSet(environment.DefaultCompatibilityVersion()))
if err == nil {
filterCompiler = compositedCompiler
compositedCompiler.CompileAndStoreVariables(convertv1beta1Variables(definitionInfo.lastReconciledValue.Spec.Variables), optionalVars, environment.StoredExpressions)
} else {
utilruntime.HandleError(err)
}
}
if len(matchConditions) > 0 {
matchExpressionAccessors := make([]cel.ExpressionAccessor, len(matchConditions))
for i := range matchConditions {
matchExpressionAccessors[i] = (*matchconditions.MatchCondition)(&matchConditions[i])
}
matcher = matchconditions.NewMatcher(filterCompiler.Compile(matchExpressionAccessors, optionalVars, environment.StoredExpressions), failurePolicy, "policy", "validate", definitionInfo.lastReconciledValue.Name)
}
bindingInfo.validator = c.newValidator(
filterCompiler.Compile(convertv1beta1Validations(definitionInfo.lastReconciledValue.Spec.Validations), optionalVars, environment.StoredExpressions),
matcher,
filterCompiler.Compile(convertv1beta1AuditAnnotations(definitionInfo.lastReconciledValue.Spec.AuditAnnotations), optionalVars, environment.StoredExpressions),
filterCompiler.Compile(convertv1beta1MessageExpressions(definitionInfo.lastReconciledValue.Spec.Validations), expressionOptionalVars, environment.StoredExpressions),
failurePolicy,
)
}
bindingInfos = append(bindingInfos, *bindingInfo)
}
var pInfo paramInfo
if paramKind := definitionInfo.lastReconciledValue.Spec.ParamKind; paramKind != nil {
if info, ok := c.paramsCRDControllers[*paramKind]; ok {
pInfo = *info
}
}
res = append(res, policyData{
definitionInfo: *definitionInfo,
paramInfo: pInfo,
bindings: bindingInfos,
})
}
c.cachedPolicies = res
return res
}
func convertv1beta1FailurePolicyTypeTov1FailurePolicyType(policyType *v1beta1.FailurePolicyType) *v1.FailurePolicyType {
if policyType == nil {
return nil
}
var v1FailPolicy v1.FailurePolicyType
if *policyType == v1beta1.Fail {
v1FailPolicy = v1.Fail
} else if *policyType == v1beta1.Ignore {
v1FailPolicy = v1.Ignore
}
return &v1FailPolicy
}
func convertv1beta1Validations(inputValidations []v1beta1.Validation) []cel.ExpressionAccessor {
celExpressionAccessor := make([]cel.ExpressionAccessor, len(inputValidations))
for i, validation := range inputValidations {
validation := ValidationCondition{
Expression: validation.Expression,
Message: validation.Message,
Reason: validation.Reason,
}
celExpressionAccessor[i] = &validation
}
return celExpressionAccessor
}
func convertv1beta1MessageExpressions(inputValidations []v1beta1.Validation) []cel.ExpressionAccessor {
celExpressionAccessor := make([]cel.ExpressionAccessor, len(inputValidations))
for i, validation := range inputValidations {
if validation.MessageExpression != "" {
condition := MessageExpressionCondition{
MessageExpression: validation.MessageExpression,
}
celExpressionAccessor[i] = &condition
}
}
return celExpressionAccessor
}
func convertv1beta1AuditAnnotations(inputValidations []v1beta1.AuditAnnotation) []cel.ExpressionAccessor {
celExpressionAccessor := make([]cel.ExpressionAccessor, len(inputValidations))
for i, validation := range inputValidations {
validation := AuditAnnotationCondition{
Key: validation.Key,
ValueExpression: validation.ValueExpression,
}
celExpressionAccessor[i] = &validation
}
return celExpressionAccessor
}
func convertv1beta1Variables(variables []v1beta1.Variable) []cel.NamedExpressionAccessor {
namedExpressions := make([]cel.NamedExpressionAccessor, len(variables))
for i, variable := range variables {
namedExpressions[i] = &Variable{Name: variable.Name, Expression: variable.Expression}
}
return namedExpressions
}
func getNamespaceName(namespace, name string) namespacedName {
return namespacedName{
namespace: namespace,
name: name,
}
}