ceph-csi/vendor/k8s.io/pod-security-admission/policy/check_runAsNonRoot.go

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/*
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 (
"fmt"
"strings"
corev1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/pod-security-admission/api"
)
/*
Containers must be required to run as non-root users.
**Restricted Fields:**
spec.securityContext.runAsNonRoot
spec.containers[*].securityContext.runAsNonRoot
spec.initContainers[*].securityContext.runAsNonRoot
**Allowed Values:**
true
undefined/null at container-level if pod-level is set to true
*/
func init() {
addCheck(CheckRunAsNonRoot)
}
// CheckRunAsNonRoot returns a restricted level check
// that requires runAsNonRoot=true in 1.0+
func CheckRunAsNonRoot() Check {
return Check{
ID: "runAsNonRoot",
Level: api.LevelRestricted,
Versions: []VersionedCheck{
{
MinimumVersion: api.MajorMinorVersion(1, 0),
CheckPod: runAsNonRoot_1_0,
},
},
}
}
func runAsNonRoot_1_0(podMetadata *metav1.ObjectMeta, podSpec *corev1.PodSpec) CheckResult {
// See KEP-127: https://github.com/kubernetes/enhancements/blob/308ba8d/keps/sig-node/127-user-namespaces/README.md?plain=1#L411-L447
if relaxPolicyForUserNamespacePod(podSpec) {
return CheckResult{Allowed: true}
}
// things that explicitly set runAsNonRoot=false
var badSetters []string
podRunAsNonRoot := false
if podSpec.SecurityContext != nil && podSpec.SecurityContext.RunAsNonRoot != nil {
if !*podSpec.SecurityContext.RunAsNonRoot {
badSetters = append(badSetters, "pod")
} else {
podRunAsNonRoot = true
}
}
// containers that explicitly set runAsNonRoot=false
var explicitlyBadContainers []string
// containers that didn't set runAsNonRoot and aren't caught by a pod-level runAsNonRoot=true
var implicitlyBadContainers []string
visitContainers(podSpec, func(container *corev1.Container) {
if container.SecurityContext != nil && container.SecurityContext.RunAsNonRoot != nil {
// container explicitly set runAsNonRoot
if !*container.SecurityContext.RunAsNonRoot {
// container explicitly set runAsNonRoot to a bad value
explicitlyBadContainers = append(explicitlyBadContainers, container.Name)
}
} else {
// container did not explicitly set runAsNonRoot
if !podRunAsNonRoot {
// no pod-level runAsNonRoot=true, so this container implicitly has a bad value
implicitlyBadContainers = append(implicitlyBadContainers, container.Name)
}
}
})
if len(explicitlyBadContainers) > 0 {
badSetters = append(
badSetters,
fmt.Sprintf(
"%s %s",
pluralize("container", "containers", len(explicitlyBadContainers)),
joinQuote(explicitlyBadContainers),
),
)
}
// pod or containers explicitly set runAsNonRoot=false
if len(badSetters) > 0 {
return CheckResult{
Allowed: false,
ForbiddenReason: "runAsNonRoot != true",
ForbiddenDetail: fmt.Sprintf("%s must not set securityContext.runAsNonRoot=false", strings.Join(badSetters, " and ")),
}
}
// pod didn't set runAsNonRoot and not all containers opted into runAsNonRoot
if len(implicitlyBadContainers) > 0 {
return CheckResult{
Allowed: false,
ForbiddenReason: "runAsNonRoot != true",
ForbiddenDetail: fmt.Sprintf(
"pod or %s %s must set securityContext.runAsNonRoot=true",
pluralize("container", "containers", len(implicitlyBadContainers)),
joinQuote(implicitlyBadContainers),
),
}
}
return CheckResult{Allowed: true}
}