-
Notifications
You must be signed in to change notification settings - Fork 1
/
rbac.go
224 lines (189 loc) · 7.73 KB
/
rbac.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
/*
Copyright 2016 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 rbac implements the authorizer.Authorizer interface using roles base access control.
package rbac
import (
"bytes"
"fmt"
"github.com/golang/glog"
rbacv1 "k8s.io/api/rbac/v1"
"k8s.io/apimachinery/pkg/labels"
utilerrors "k8s.io/apimachinery/pkg/util/errors"
"k8s.io/apiserver/pkg/authentication/user"
"k8s.io/apiserver/pkg/authorization/authorizer"
rbaclisters "k8s.io/client-go/listers/rbac/v1"
rbacv1helpers "k8s.io/kubernetes/pkg/apis/rbac/v1"
rbacregistryvalidation "k8s.io/kubernetes/pkg/registry/rbac/validation"
)
type RequestToRuleMapper interface {
// RulesFor returns all known PolicyRules and any errors that happened while locating those rules.
// Any rule returned is still valid, since rules are deny by default. If you can pass with the rules
// supplied, you do not have to fail the request. If you cannot, you should indicate the error along
// with your denial.
RulesFor(subject user.Info, namespace string) ([]rbacv1.PolicyRule, error)
// VisitRulesFor invokes visitor() with each rule that applies to a given user in a given namespace,
// and each error encountered resolving those rules. Rule may be nil if err is non-nil.
// If visitor() returns false, visiting is short-circuited.
VisitRulesFor(user user.Info, namespace string, visitor func(source fmt.Stringer, rule *rbacv1.PolicyRule, err error) bool)
}
type RBACAuthorizer struct {
authorizationRuleResolver RequestToRuleMapper
}
// authorizingVisitor short-circuits once allowed, and collects any resolution errors encountered
type authorizingVisitor struct {
requestAttributes authorizer.Attributes
allowed bool
reason string
errors []error
}
func (v *authorizingVisitor) visit(source fmt.Stringer, rule *rbacv1.PolicyRule, err error) bool {
if rule != nil && RuleAllows(v.requestAttributes, rule) {
v.allowed = true
v.reason = fmt.Sprintf("RBAC: allowed by %s", source.String())
return false
}
if err != nil {
v.errors = append(v.errors, err)
}
return true
}
func (r *RBACAuthorizer) Authorize(requestAttributes authorizer.Attributes) (authorizer.Decision, string, error) {
ruleCheckingVisitor := &authorizingVisitor{requestAttributes: requestAttributes}
r.authorizationRuleResolver.VisitRulesFor(requestAttributes.GetUser(), requestAttributes.GetNamespace(), ruleCheckingVisitor.visit)
if ruleCheckingVisitor.allowed {
return authorizer.DecisionAllow, ruleCheckingVisitor.reason, nil
}
// Build a detailed log of the denial.
// Make the whole block conditional so we don't do a lot of string-building we won't use.
if glog.V(5) {
var operation string
if requestAttributes.IsResourceRequest() {
b := &bytes.Buffer{}
b.WriteString(`"`)
b.WriteString(requestAttributes.GetVerb())
b.WriteString(`" resource "`)
b.WriteString(requestAttributes.GetResource())
if len(requestAttributes.GetAPIGroup()) > 0 {
b.WriteString(`.`)
b.WriteString(requestAttributes.GetAPIGroup())
}
if len(requestAttributes.GetSubresource()) > 0 {
b.WriteString(`/`)
b.WriteString(requestAttributes.GetSubresource())
}
b.WriteString(`"`)
if len(requestAttributes.GetName()) > 0 {
b.WriteString(` named "`)
b.WriteString(requestAttributes.GetName())
b.WriteString(`"`)
}
operation = b.String()
} else {
operation = fmt.Sprintf("%q nonResourceURL %q", requestAttributes.GetVerb(), requestAttributes.GetPath())
}
var scope string
if ns := requestAttributes.GetNamespace(); len(ns) > 0 {
scope = fmt.Sprintf("in namespace %q", ns)
} else {
scope = "cluster-wide"
}
glog.Infof("RBAC DENY: user %q groups %q cannot %s %s", requestAttributes.GetUser().GetName(), requestAttributes.GetUser().GetGroups(), operation, scope)
}
reason := ""
if len(ruleCheckingVisitor.errors) > 0 {
reason = fmt.Sprintf("RBAC: %v", utilerrors.NewAggregate(ruleCheckingVisitor.errors))
}
return authorizer.DecisionNoOpinion, reason, nil
}
func (r *RBACAuthorizer) RulesFor(user user.Info, namespace string) ([]authorizer.ResourceRuleInfo, []authorizer.NonResourceRuleInfo, bool, error) {
var (
resourceRules []authorizer.ResourceRuleInfo
nonResourceRules []authorizer.NonResourceRuleInfo
)
policyRules, err := r.authorizationRuleResolver.RulesFor(user, namespace)
for _, policyRule := range policyRules {
if len(policyRule.Resources) > 0 {
r := authorizer.DefaultResourceRuleInfo{
Verbs: policyRule.Verbs,
APIGroups: policyRule.APIGroups,
Resources: policyRule.Resources,
ResourceNames: policyRule.ResourceNames,
}
var resourceRule authorizer.ResourceRuleInfo = &r
resourceRules = append(resourceRules, resourceRule)
}
if len(policyRule.NonResourceURLs) > 0 {
r := authorizer.DefaultNonResourceRuleInfo{
Verbs: policyRule.Verbs,
NonResourceURLs: policyRule.NonResourceURLs,
}
var nonResourceRule authorizer.NonResourceRuleInfo = &r
nonResourceRules = append(nonResourceRules, nonResourceRule)
}
}
return resourceRules, nonResourceRules, false, err
}
func New(roles rbacregistryvalidation.RoleGetter, roleBindings rbacregistryvalidation.RoleBindingLister, clusterRoles rbacregistryvalidation.ClusterRoleGetter, clusterRoleBindings rbacregistryvalidation.ClusterRoleBindingLister) *RBACAuthorizer {
authorizer := &RBACAuthorizer{
authorizationRuleResolver: rbacregistryvalidation.NewDefaultRuleResolver(
roles, roleBindings, clusterRoles, clusterRoleBindings,
),
}
return authorizer
}
func RulesAllow(requestAttributes authorizer.Attributes, rules ...rbacv1.PolicyRule) bool {
for i := range rules {
if RuleAllows(requestAttributes, &rules[i]) {
return true
}
}
return false
}
func RuleAllows(requestAttributes authorizer.Attributes, rule *rbacv1.PolicyRule) bool {
if requestAttributes.IsResourceRequest() {
combinedResource := requestAttributes.GetResource()
if len(requestAttributes.GetSubresource()) > 0 {
combinedResource = requestAttributes.GetResource() + "/" + requestAttributes.GetSubresource()
}
return rbacv1helpers.VerbMatches(rule, requestAttributes.GetVerb()) &&
rbacv1helpers.APIGroupMatches(rule, requestAttributes.GetAPIGroup()) &&
rbacv1helpers.ResourceMatches(rule, combinedResource, requestAttributes.GetSubresource()) &&
rbacv1helpers.ResourceNameMatches(rule, requestAttributes.GetName())
}
return rbacv1helpers.VerbMatches(rule, requestAttributes.GetVerb()) &&
rbacv1helpers.NonResourceURLMatches(rule, requestAttributes.GetPath())
}
type RoleGetter struct {
Lister rbaclisters.RoleLister
}
func (g *RoleGetter) GetRole(namespace, name string) (*rbacv1.Role, error) {
return g.Lister.Roles(namespace).Get(name)
}
type RoleBindingLister struct {
Lister rbaclisters.RoleBindingLister
}
func (l *RoleBindingLister) ListRoleBindings(namespace string) ([]*rbacv1.RoleBinding, error) {
return l.Lister.RoleBindings(namespace).List(labels.Everything())
}
type ClusterRoleGetter struct {
Lister rbaclisters.ClusterRoleLister
}
func (g *ClusterRoleGetter) GetClusterRole(name string) (*rbacv1.ClusterRole, error) {
return g.Lister.Get(name)
}
type ClusterRoleBindingLister struct {
Lister rbaclisters.ClusterRoleBindingLister
}
func (l *ClusterRoleBindingLister) ListClusterRoleBindings() ([]*rbacv1.ClusterRoleBinding, error) {
return l.Lister.List(labels.Everything())
}