-
Notifications
You must be signed in to change notification settings - Fork 59
/
validator.go
317 lines (279 loc) · 11 KB
/
validator.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
// Package podsecurityadmissionconfigurationtemplate is used for validating podsecurityadmissionconfigurationtemplate admission requests.
package podsecurityadmissionconfigurationtemplate
import (
"fmt"
"net/http"
"strings"
"time"
mgmtv3 "github.com/rancher/rancher/pkg/apis/management.cattle.io/v3"
provv1 "github.com/rancher/rancher/pkg/apis/provisioning.cattle.io/v1"
"github.com/rancher/webhook/pkg/admission"
v3 "github.com/rancher/webhook/pkg/generated/controllers/management.cattle.io/v3"
v1 "github.com/rancher/webhook/pkg/generated/controllers/provisioning.cattle.io/v1"
objectsv3 "github.com/rancher/webhook/pkg/generated/objects/management.cattle.io/v3"
admissionv1 "k8s.io/api/admission/v1"
admissionregistrationv1 "k8s.io/api/admissionregistration/v1"
machinery "k8s.io/apimachinery/pkg/api/validation"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/apimachinery/pkg/util/sets"
"k8s.io/apimachinery/pkg/util/validation/field"
"k8s.io/pod-security-admission/api"
"k8s.io/utils/trace"
)
var gvr = schema.GroupVersionResource{
Group: "management.cattle.io",
Version: "v3",
Resource: "podsecurityadmissionconfigurationtemplates",
}
// Validator validates the PodSecurityAdmissionConfigurationTemplate admission request.
type Validator struct {
admitter admitter
}
const (
byPodSecurityAdmissionConfigurationName = "podSecurityAdmissionConfigurationName"
rancherPrivilegedPSACTName = "rancher-privileged"
rancherRestrictedPSACTName = "rancher-restricted"
)
// NewValidator returns a validator for PodSecurityAdmissionConfigurationTemplates.
func NewValidator(managementCache v3.ClusterCache, provisioningCache v1.ClusterCache) *Validator {
adm := admitter{
ManagementClusterCache: managementCache,
provisioningClusterCache: provisioningCache,
}
adm.ManagementClusterCache.AddIndexer(byPodSecurityAdmissionConfigurationName, byPodSecurityAdmissionConfigurationTemplateV3)
adm.provisioningClusterCache.AddIndexer(byPodSecurityAdmissionConfigurationName, byPodSecurityAdmissionConfigurationTemplateV1)
return &Validator{
admitter: adm,
}
}
// ValidatingWebhook returns the ValidatingWebhook used for this CRD.
func (v *Validator) ValidatingWebhook(clientConfig admissionregistrationv1.WebhookClientConfig) []admissionregistrationv1.ValidatingWebhook {
valWebhook := admission.NewDefaultValidatingWebhook(v, clientConfig, admissionregistrationv1.AllScopes, v.Operations())
valWebhook.FailurePolicy = admission.Ptr(admissionregistrationv1.Ignore)
return []admissionregistrationv1.ValidatingWebhook{*valWebhook}
}
func byPodSecurityAdmissionConfigurationTemplateV1(obj *provv1.Cluster) ([]string, error) {
if obj.Spec.DefaultPodSecurityAdmissionConfigurationTemplateName == "" {
return nil, nil
}
return []string{obj.Spec.DefaultPodSecurityAdmissionConfigurationTemplateName}, nil
}
func byPodSecurityAdmissionConfigurationTemplateV3(obj *mgmtv3.Cluster) ([]string, error) {
if obj.Spec.DefaultPodSecurityAdmissionConfigurationTemplateName == "" {
return nil, nil
}
return []string{obj.Spec.DefaultPodSecurityAdmissionConfigurationTemplateName}, nil
}
// GVR returns the GroupVersionKind for this CRD.
func (v *Validator) GVR() schema.GroupVersionResource {
return gvr
}
// Operations returns list of operations handled by this validator.
func (v *Validator) Operations() []admissionregistrationv1.OperationType {
return []admissionregistrationv1.OperationType{admissionregistrationv1.Update, admissionregistrationv1.Create, admissionregistrationv1.Delete}
}
// Admitters returns the admitter objects used to validate podsecurityadmissionconfigurationtemplate.
func (v *Validator) Admitters() []admission.Admitter {
return []admission.Admitter{&v.admitter}
}
type admitter struct {
ManagementClusterCache v3.ClusterCache
provisioningClusterCache v1.ClusterCache
}
// Admit handles the webhook admission request sent to this webhook.
func (a *admitter) Admit(req *admission.Request) (*admissionv1.AdmissionResponse, error) {
listTrace := trace.New("PodSecurityAdmissionConfigurationTemplate Admit", trace.Field{Key: "user", Value: req.UserInfo.Username})
defer listTrace.LogIfLong(2 * time.Second)
resp := &admissionv1.AdmissionResponse{}
oldTemplate, newTemplate, err := objectsv3.PodSecurityAdmissionConfigurationTemplateOldAndNewFromRequest(&req.AdmissionRequest)
if err != nil {
return resp, fmt.Errorf("failed to parse PodSecurityAdmissionConfigurationTemplate object from request:%w", err)
}
switch req.Operation {
case admissionv1.Create, admissionv1.Update:
err = a.validateConfiguration(newTemplate)
if err != nil {
resp.Result = &metav1.Status{
Status: "Failure",
Message: err.Error(),
Reason: metav1.StatusReasonBadRequest,
Code: http.StatusUnprocessableEntity,
}
resp.Allowed = false
break
}
resp.Allowed = true
case admissionv1.Delete:
// do not allow the default 'restricted' and 'privileged' templates from being deleted
if oldTemplate.Name == rancherPrivilegedPSACTName || oldTemplate.Name == rancherRestrictedPSACTName {
resp.Result = &metav1.Status{
Status: "Failure",
Message: fmt.Sprintf("Cannot delete built-in template '%s'", oldTemplate.Name),
Reason: metav1.StatusReasonForbidden,
Code: http.StatusForbidden,
}
resp.Allowed = false
break
}
clustersUsingTemplate, clusterType, err := a.handleDeletion(oldTemplate)
if err != nil {
// error encountered with indexer
resp.Result = &metav1.Status{
Status: "Failure",
Message: err.Error(),
Reason: metav1.StatusReasonInternalError,
Code: http.StatusInternalServerError,
}
resp.Allowed = false
break
}
if clustersUsingTemplate > 0 {
// template in use, cannot be deleted
message := fmt.Sprintf("Cannot delete template '%s' as it is being used by %d %s clusters", oldTemplate.Name, clustersUsingTemplate, clusterType)
if clustersUsingTemplate == 1 {
message = fmt.Sprintf("Cannot delete template '%s' as it is being used by a %s cluster", oldTemplate.Name, clusterType)
}
resp.Result = &metav1.Status{
Status: "Failure",
Message: message,
Reason: metav1.StatusReasonBadRequest,
Code: http.StatusBadRequest,
}
resp.Allowed = false
break
}
resp.Allowed = true
default:
resp.Allowed = true
}
return resp, nil
}
func (a *admitter) handleDeletion(oldTemplate *mgmtv3.PodSecurityAdmissionConfigurationTemplate) (clustersUsingTemplate int, clusterType string, err error) {
// we can't allow templates to be deleted if they are being used by active clusters. Depending on the distro,
// the template reference could be stored on the v1.Cluster or v3.Cluster.
mgmtClusters, err := a.ManagementClusterCache.GetByIndex(byPodSecurityAdmissionConfigurationName, oldTemplate.Name)
if err != nil {
return 0, "management", fmt.Errorf("error encountered within management cluster indexer: %w", err)
} else if len(mgmtClusters) > 0 {
return len(mgmtClusters), "management", nil
}
provClusters, err := a.provisioningClusterCache.GetByIndex(byPodSecurityAdmissionConfigurationName, oldTemplate.Name)
if err != nil {
return 0, "provisioning", fmt.Errorf("error encountered within provisioning cluster indexer: %w", err)
} else if len(provClusters) > 0 {
return len(provClusters), "provisioning", nil
}
return 0, "", nil
}
func (a *admitter) validateConfiguration(configurationTemplate *mgmtv3.PodSecurityAdmissionConfigurationTemplate) error {
defaults := configurationTemplate.Configuration.Defaults
// validate any provided defaults
if err := validateLevel(field.NewPath("defaults", "enforce"), defaults.Enforce).ToAggregate(); err != nil {
return err
}
if err := validateVersion(field.NewPath("defaults", "enforce-version"), defaults.EnforceVersion).ToAggregate(); err != nil {
return err
}
if err := validateLevel(field.NewPath("defaults", "warn"), defaults.Warn).ToAggregate(); err != nil {
return err
}
if err := validateVersion(field.NewPath("defaults", "warn-version"), defaults.WarnVersion).ToAggregate(); err != nil {
return err
}
if err := validateLevel(field.NewPath("defaults", "audit"), defaults.Audit).ToAggregate(); err != nil {
return err
}
if err := validateVersion(field.NewPath("defaults", "audit-version"), defaults.AuditVersion).ToAggregate(); err != nil {
return err
}
// validate exemptions
if err := validateUsernames(configurationTemplate).ToAggregate(); err != nil {
return err
}
if err := validateRuntimeClasses(configurationTemplate).ToAggregate(); err != nil {
return err
}
return validateNamespaces(configurationTemplate).ToAggregate()
}
func validateLevel(p *field.Path, value string) field.ErrorList {
if value == "" {
return nil
}
errs := field.ErrorList{}
_, err := api.ParseLevel(value)
if err != nil {
errs = append(errs, field.Invalid(p, value, err.Error()))
}
return errs
}
func validateVersion(p *field.Path, value string) field.ErrorList {
if value == "" {
return nil
}
errs := field.ErrorList{}
_, err := api.ParseVersion(value)
if err != nil {
errs = append(errs, field.Invalid(p, value, err.Error()))
}
return errs
}
func validateNamespaces(template *mgmtv3.PodSecurityAdmissionConfigurationTemplate) field.ErrorList {
errs := field.ErrorList{}
validSet := sets.NewString()
configuration := template.Configuration
for i, ns := range configuration.Exemptions.Namespaces {
err := machinery.ValidateNamespaceName(ns, false)
if len(err) > 0 {
path := field.NewPath("exemptions", "namespaces").Index(i)
errs = append(errs, field.Invalid(path, ns, strings.Join(err, ", ")))
continue
}
if validSet.Has(ns) {
path := field.NewPath("exemptions", "namespaces").Index(i)
errs = append(errs, field.Duplicate(path, ns))
continue
}
validSet.Insert(ns)
}
return errs
}
func validateRuntimeClasses(template *mgmtv3.PodSecurityAdmissionConfigurationTemplate) field.ErrorList {
errs := field.ErrorList{}
validSet := sets.NewString()
configuration := template.Configuration
for i, rc := range configuration.Exemptions.RuntimeClasses {
err := machinery.NameIsDNSSubdomain(rc, false)
if len(err) > 0 {
path := field.NewPath("exemptions", "runtimeClasses").Index(i)
errs = append(errs, field.Invalid(path, rc, strings.Join(err, ", ")))
continue
}
if validSet.Has(rc) {
path := field.NewPath("exemptions", "runtimeClasses").Index(i)
errs = append(errs, field.Duplicate(path, rc))
continue
}
validSet.Insert(rc)
}
return errs
}
func validateUsernames(template *mgmtv3.PodSecurityAdmissionConfigurationTemplate) field.ErrorList {
errs := field.ErrorList{}
validSet := sets.NewString()
configuration := template.Configuration
for i, uname := range configuration.Exemptions.Usernames {
if uname == "" {
path := field.NewPath("exemptions", "usernames").Index(i)
errs = append(errs, field.Invalid(path, uname, "username must not be empty"))
continue
}
if validSet.Has(uname) {
path := field.NewPath("exemptions", "usernames").Index(i)
errs = append(errs, field.Duplicate(path, uname))
continue
}
validSet.Insert(uname)
}
return errs
}