func (a *gcPermissionsEnforcement) Admit(attributes admission.Attributes) (err error) {
// if we aren't changing owner references, then the edit is always allowed
if !isChangingOwnerReference(attributes.GetObject(), attributes.GetOldObject()) {
return nil
}
deleteAttributes := authorizer.AttributesRecord{
User: attributes.GetUserInfo(),
Verb: "delete",
Namespace: attributes.GetNamespace(),
APIGroup: attributes.GetResource().Group,
APIVersion: attributes.GetResource().Version,
Resource: attributes.GetResource().Resource,
Subresource: attributes.GetSubresource(),
Name: attributes.GetName(),
ResourceRequest: true,
Path: "",
}
allowed, reason, err := a.authorizer.Authorize(deleteAttributes)
if allowed {
return nil
}
return admission.NewForbidden(attributes, fmt.Errorf("cannot set an ownerRef on a resource you can't delete: %v, %v", reason, err))
}
// Admit determines if the pod should be admitted based on the requested security context
// and the available PSPs.
//
// 1. Find available PSPs.
// 2. Create the providers, includes setting pre-allocated values if necessary.
// 3. Try to generate and validate a PSP with providers. If we find one then admit the pod
// with the validated PSP. If we don't find any reject the pod and give all errors from the
// failed attempts.
func (c *podSecurityPolicyPlugin) Admit(a admission.Attributes) error {
if a.GetResource().GroupResource() != api.Resource("pods") {
return nil
}
if len(a.GetSubresource()) != 0 {
return nil
}
pod, ok := a.GetObject().(*api.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 pod security policies for pod %s (generate: %s)", pod.Name, pod.GenerateName)
var saInfo user.Info
if len(pod.Spec.ServiceAccountName) > 0 {
saInfo = serviceaccount.UserInfo(a.GetNamespace(), pod.Spec.ServiceAccountName, "")
}
matchedPolicies, err := c.pspMatcher(c.store, a.GetUserInfo(), saInfo, c.authz)
if err != nil {
return admission.NewForbidden(a, err)
}
// if we have no policies and want to succeed then return. Otherwise we'll end up with no
// providers and fail with "unable to validate against any pod security policy" below.
if len(matchedPolicies) == 0 && !c.failOnNoPolicies {
return nil
}
providers, errs := c.createProvidersFromPolicies(matchedPolicies, pod.Namespace)
logProviders(pod, providers, errs)
if len(providers) == 0 {
return admission.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 := assignSecurityContext(provider, pod, field.NewPath(fmt.Sprintf("provider %s: ", provider.GetPSPName()))); 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.GetPSPName())
if pod.ObjectMeta.Annotations == nil {
pod.ObjectMeta.Annotations = map[string]string{}
}
pod.ObjectMeta.Annotations[psputil.ValidatedPSPAnnotation] = provider.GetPSPName()
return nil
}
// we didn't validate against any provider, reject the pod and give the errors for each attempt
glog.V(4).Infof("unable to validate pod %s (generate: %s) against any pod security policy: %v", pod.Name, pod.GenerateName, validationErrs)
return admission.NewForbidden(a, fmt.Errorf("unable to validate against any pod security policy: %v", validationErrs))
}