// FillPodSecurityPolicySubjectReviewStatus fills PodSecurityPolicySubjectReviewStatus assigning SecurityContectConstraint to the PodSpec
func FillPodSecurityPolicySubjectReviewStatus(s *securityapi.PodSecurityPolicySubjectReviewStatus, provider kscc.SecurityContextConstraintsProvider, spec kapi.PodSpec, constraint *kapi.SecurityContextConstraints) (bool, error) {
pod := &kapi.Pod{
Spec: spec,
}
if errs := oscc.AssignSecurityContext(provider, pod, field.NewPath(fmt.Sprintf("provider %s: ", provider.GetSCCName()))); len(errs) > 0 {
glog.Errorf("unable to assign SecurityContextConstraints provider: %v", errs)
s.Reason = "CantAssignSecurityContextConstraintProvider"
return false, fmt.Errorf("unable to assign SecurityContextConstraints provider: %v", errs.ToAggregate())
}
ref, err := kapi.GetReference(constraint)
if err != nil {
s.Reason = "CantObtainReference"
return false, fmt.Errorf("unable to get SecurityContextConstraints reference: %v", err)
}
s.AllowedBy = ref
if len(spec.ServiceAccountName) > 0 {
s.Template.Spec = pod.Spec
}
return true, nil
}
// Admit determines if the pod should be admitted based on the requested security context
// and the available SCCs.
//
// 1. Find SCCs for the user.
// 2. Find SCCs for the SA. If there is an error retrieving SA SCCs it is not fatal.
// 3. Remove duplicates between the user/SA SCCs.
// 4. Create the providers, includes setting pre-allocated values if necessary.
// 5. Try to generate and validate an SCC with providers. If we find one then admit the pod
// with the validated SCC. If we don't find any reject the pod and give all errors from the
// failed attempts.
// On updates, the BeforeUpdate of the pod strategy only zeroes out the status. That means that
// any change that claims the pod is no longer privileged will be removed. That should hold until
// we get a true old/new set of objects in.
func (c *constraint) Admit(a kadmission.Attributes) error {
if a.GetResource().GroupResource() != kapi.Resource("pods") {
return nil
}
if len(a.GetSubresource()) != 0 {
return nil
}
pod, ok := a.GetObject().(*kapi.Pod)
// if we can't convert then we don't handle this object so just return
if !ok {
return nil
}
// get all constraints that are usable by the user
glog.V(4).Infof("getting security context constraints for pod %s (generate: %s) in namespace %s with user info %v", pod.Name, pod.GenerateName, a.GetNamespace(), a.GetUserInfo())
sccMatcher := oscc.NewDefaultSCCMatcher(c.sccLister)
matchedConstraints, err := sccMatcher.FindApplicableSCCs(a.GetUserInfo())
if err != nil {
return kadmission.NewForbidden(a, err)
}
// get all constraints that are usable by the SA
if len(pod.Spec.ServiceAccountName) > 0 {
userInfo := serviceaccount.UserInfo(a.GetNamespace(), pod.Spec.ServiceAccountName, "")
glog.V(4).Infof("getting security context constraints for pod %s (generate: %s) with service account info %v", pod.Name, pod.GenerateName, userInfo)
saConstraints, err := sccMatcher.FindApplicableSCCs(userInfo)
if err != nil {
return kadmission.NewForbidden(a, err)
}
matchedConstraints = append(matchedConstraints, saConstraints...)
}
// remove duplicate constraints and sort
matchedConstraints = oscc.DeduplicateSecurityContextConstraints(matchedConstraints)
sort.Sort(oscc.ByPriority(matchedConstraints))
providers, errs := oscc.CreateProvidersFromConstraints(a.GetNamespace(), matchedConstraints, c.client)
logProviders(pod, providers, errs)
if len(providers) == 0 {
return kadmission.NewForbidden(a, fmt.Errorf("no providers available to validate pod request"))
}
// all containers in a single pod must validate under a single provider or we will reject the request
validationErrs := field.ErrorList{}
for _, provider := range providers {
if errs := oscc.AssignSecurityContext(provider, pod, field.NewPath(fmt.Sprintf("provider %s: ", provider.GetSCCName()))); len(errs) > 0 {
validationErrs = append(validationErrs, errs...)
continue
}
// the entire pod validated, annotate and accept the pod
glog.V(4).Infof("pod %s (generate: %s) validated against provider %s", pod.Name, pod.GenerateName, provider.GetSCCName())
if pod.ObjectMeta.Annotations == nil {
pod.ObjectMeta.Annotations = map[string]string{}
}
pod.ObjectMeta.Annotations[allocator.ValidatedSCCAnnotation] = provider.GetSCCName()
return nil
}
// we didn't validate against any security context constraint provider, reject the pod and give the errors for each attempt
glog.V(4).Infof("unable to validate pod %s (generate: %s) against any security context constraint: %v", pod.Name, pod.GenerateName, validationErrs)
return kadmission.NewForbidden(a, fmt.Errorf("unable to validate against any security context constraint: %v", validationErrs))
}