PodSecurity: sysctls: cleanup

Add documentation and unit tests for messages
This commit is contained in:
Jordan Liggitt 2021-07-08 00:44:10 -04:00
parent e178695c25
commit 19c8ab297c
2 changed files with 80 additions and 2 deletions

View File

@ -25,6 +25,26 @@ import (
"k8s.io/pod-security-admission/api"
)
/*
Sysctls can disable security mechanisms or affect all containers on a host,
and should be disallowed except for an allowed "safe" subset.
A sysctl is considered safe if it is namespaced in the container or the Pod,
and it is isolated from other Pods or processes on the same Node.
**Restricted Fields:**
spec.securityContext.sysctls[*].name
**Allowed Values:**
'kernel.shm_rmid_forced'
'net.ipv4.ip_local_port_range'
'net.ipv4.tcp_syncookies'
'net.ipv4.ping_group_range'
'net.ipv4.ip_unprivileged_port_start'
*/
func init() {
addCheck(CheckSysctls)
}
@ -38,7 +58,7 @@ func CheckSysctls() Check {
Versions: []VersionedCheck{
{
MinimumVersion: api.MajorMinorVersion(1, 0),
CheckPod: checkSysctls_1_0,
CheckPod: sysctls_1_0,
},
},
}
@ -54,7 +74,7 @@ var (
)
)
func checkSysctls_1_0(podMetadata *metav1.ObjectMeta, podSpec *corev1.PodSpec) CheckResult {
func sysctls_1_0(podMetadata *metav1.ObjectMeta, podSpec *corev1.PodSpec) CheckResult {
var forbiddenSysctls []string
if podSpec.SecurityContext != nil {

View File

@ -0,0 +1,58 @@
/*
Copyright 2021 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 policy
import (
"testing"
corev1 "k8s.io/api/core/v1"
)
func TestSysctls(t *testing.T) {
tests := []struct {
name string
pod *corev1.Pod
expectReason string
expectDetail string
}{
{
name: "forbidden sysctls",
pod: &corev1.Pod{Spec: corev1.PodSpec{
SecurityContext: &corev1.PodSecurityContext{
Sysctls: []corev1.Sysctl{{Name: "a"}, {Name: "b"}},
},
}},
expectReason: `forbidden sysctls`,
expectDetail: `a, b`,
},
}
for _, tc := range tests {
t.Run(tc.name, func(t *testing.T) {
result := sysctls_1_0(&tc.pod.ObjectMeta, &tc.pod.Spec)
if result.Allowed {
t.Fatal("expected disallowed")
}
if e, a := tc.expectReason, result.ForbiddenReason; e != a {
t.Errorf("expected\n%s\ngot\n%s", e, a)
}
if e, a := tc.expectDetail, result.ForbiddenDetail; e != a {
t.Errorf("expected\n%s\ngot\n%s", e, a)
}
})
}
}