func (p *provision) Admit(a admission.Attributes) (err error) {
defaultVersion, kind, err := api.RESTMapper.VersionAndKindForResource(a.GetResource())
if err != nil {
return admission.NewForbidden(a, err)
}
mapping, err := api.RESTMapper.RESTMapping(kind, defaultVersion)
if err != nil {
return admission.NewForbidden(a, err)
}
if mapping.Scope.Name() != meta.RESTScopeNameNamespace {
return nil
}
namespace := &api.Namespace{
ObjectMeta: api.ObjectMeta{
Name: a.GetNamespace(),
Namespace: "",
},
Status: api.NamespaceStatus{},
}
_, exists, err := p.store.Get(namespace)
if err != nil {
return admission.NewForbidden(a, err)
}
if exists {
return nil
}
_, err = p.client.Namespaces().Create(namespace)
if err != nil && !errors.IsAlreadyExists(err) {
return admission.NewForbidden(a, err)
}
return nil
}
func (l *lifecycle) Admit(a admission.Attributes) (err error) {
// prevent deletion of immortal namespaces
if a.GetOperation() == admission.Delete && a.GetKind() == "Namespace" && l.immortalNamespaces.Has(a.GetName()) {
return errors.NewForbidden(a.GetKind(), a.GetName(), fmt.Errorf("namespace can never be deleted"))
}
defaultVersion, kind, err := api.RESTMapper.VersionAndKindForResource(a.GetResource())
if err != nil {
return errors.NewInternalError(err)
}
mapping, err := api.RESTMapper.RESTMapping(kind, defaultVersion)
if err != nil {
return errors.NewInternalError(err)
}
if mapping.Scope.Name() != meta.RESTScopeNameNamespace {
return nil
}
namespaceObj, exists, err := l.store.Get(&api.Namespace{
ObjectMeta: api.ObjectMeta{
Name: a.GetNamespace(),
Namespace: "",
},
})
if err != nil {
return errors.NewInternalError(err)
}
// refuse to operate on non-existent namespaces
if !exists {
// in case of latency in our caches, make a call direct to storage to verify that it truly exists or not
namespaceObj, err = l.client.Namespaces().Get(a.GetNamespace())
if err != nil {
if errors.IsNotFound(err) {
return err
}
return errors.NewInternalError(err)
}
}
// ensure that we're not trying to create objects in terminating namespaces
if a.GetOperation() == admission.Create {
namespace := namespaceObj.(*api.Namespace)
if namespace.Status.Phase != api.NamespaceTerminating {
return nil
}
// TODO: This should probably not be a 403
return admission.NewForbidden(a, fmt.Errorf("Unable to create new content in namespace %s because it is being terminated.", a.GetNamespace()))
}
return nil
}
func (ir initialResources) Admit(a admission.Attributes) (err error) {
// Ignore all calls to subresources or resources other than pods.
if a.GetSubresource() != "" || a.GetResource() != string(api.ResourcePods) {
return nil
}
pod, ok := a.GetObject().(*api.Pod)
if !ok {
return apierrors.NewBadRequest("Resource was marked with kind Pod but was unable to be converted")
}
ir.estimateAndFillResourcesIfNotSet(pod)
return nil
}
// Admit admits resources into cluster that do not violate any defined LimitRange in the namespace
func (l *limitRanger) Admit(a admission.Attributes) (err error) {
// Ignore all calls to subresources
if a.GetSubresource() != "" {
return nil
}
obj := a.GetObject()
resource := a.GetResource()
name := "Unknown"
if obj != nil {
name, _ = meta.NewAccessor().Name(obj)
if len(name) == 0 {
name, _ = meta.NewAccessor().GenerateName(obj)
}
}
key := &api.LimitRange{
ObjectMeta: api.ObjectMeta{
Namespace: a.GetNamespace(),
Name: "",
},
}
items, err := l.indexer.Index("namespace", key)
if err != nil {
return admission.NewForbidden(a, fmt.Errorf("Unable to %s %s at this time because there was an error enforcing limit ranges", a.GetOperation(), resource))
}
if len(items) == 0 {
return nil
}
// ensure it meets each prescribed min/max
for i := range items {
limitRange := items[i].(*api.LimitRange)
err = l.limitFunc(limitRange, a.GetResource(), a.GetObject())
if err != nil {
return admission.NewForbidden(a, err)
}
}
return nil
}
func (e *exists) Admit(a admission.Attributes) (err error) {
defaultVersion, kind, err := api.RESTMapper.VersionAndKindForResource(a.GetResource())
if err != nil {
return errors.NewInternalError(err)
}
mapping, err := api.RESTMapper.RESTMapping(kind, defaultVersion)
if err != nil {
return errors.NewInternalError(err)
}
if mapping.Scope.Name() != meta.RESTScopeNameNamespace {
return nil
}
namespace := &api.Namespace{
ObjectMeta: api.ObjectMeta{
Name: a.GetNamespace(),
Namespace: "",
},
Status: api.NamespaceStatus{},
}
_, exists, err := e.store.Get(namespace)
if err != nil {
return errors.NewInternalError(err)
}
if exists {
return nil
}
// in case of latency in our caches, make a call direct to storage to verify that it truly exists or not
_, err = e.client.Namespaces().Get(a.GetNamespace())
if err != nil {
if errors.IsNotFound(err) {
return err
}
return errors.NewInternalError(err)
}
return nil
}
// Admit will deny any SecurityContext that defines options that were not previously available in the api.Container
// struct (Capabilities and Privileged)
func (p *plugin) Admit(a admission.Attributes) (err error) {
if a.GetResource() != string(api.ResourcePods) {
return nil
}
pod, ok := a.GetObject().(*api.Pod)
if !ok {
return apierrors.NewBadRequest("Resource was marked with kind Pod but was unable to be converted")
}
for _, v := range pod.Spec.Containers {
if v.SecurityContext != nil {
if v.SecurityContext.SELinuxOptions != nil {
return apierrors.NewForbidden(a.GetResource(), pod.Name, fmt.Errorf("SecurityContext.SELinuxOptions is forbidden"))
}
if v.SecurityContext.RunAsUser != nil {
return apierrors.NewForbidden(a.GetResource(), pod.Name, fmt.Errorf("SecurityContext.RunAsUser is forbidden"))
}
}
}
return nil
}
func (q *quota) Admit(a admission.Attributes) (err error) {
if a.GetSubresource() != "" {
return nil
}
if a.GetOperation() == "DELETE" {
return nil
}
key := &api.ResourceQuota{
ObjectMeta: api.ObjectMeta{
Namespace: a.GetNamespace(),
Name: "",
},
}
// concurrent operations that modify quota tracked resources can cause a conflict when incrementing usage
// as a result, we will attempt to increment quota usage per request up to numRetries limit
// we fuzz each retry with an interval period to attempt to improve end-user experience during concurrent operations
numRetries := 10
interval := time.Duration(rand.Int63n(90)+int64(10)) * time.Millisecond
items, err := q.indexer.Index("namespace", key)
if err != nil {
return admission.NewForbidden(a, fmt.Errorf("unable to %s %s at this time because there was an error enforcing quota", a.GetOperation(), a.GetResource()))
}
if len(items) == 0 {
return nil
}
for i := range items {
quota := items[i].(*api.ResourceQuota)
for retry := 1; retry <= numRetries; retry++ {
// we cannot modify the value directly in the cache, so we copy
status := &api.ResourceQuotaStatus{
Hard: api.ResourceList{},
Used: api.ResourceList{},
}
for k, v := range quota.Status.Hard {
status.Hard[k] = *v.Copy()
}
for k, v := range quota.Status.Used {
status.Used[k] = *v.Copy()
}
dirty, err := IncrementUsage(a, status, q.client)
if err != nil {
return admission.NewForbidden(a, err)
}
if dirty {
// construct a usage record
usage := api.ResourceQuota{
ObjectMeta: api.ObjectMeta{
Name: quota.Name,
Namespace: quota.Namespace,
ResourceVersion: quota.ResourceVersion,
Labels: quota.Labels,
Annotations: quota.Annotations},
}
usage.Status = *status
_, err = q.client.ResourceQuotas(usage.Namespace).UpdateStatus(&usage)
if err == nil {
break
}
// we have concurrent requests to update quota, so look to retry if needed
if retry == numRetries {
return admission.NewForbidden(a, fmt.Errorf("unable to %s %s at this time because there are too many concurrent requests to increment quota", a.GetOperation(), a.GetResource()))
}
time.Sleep(interval)
// manually get the latest quota
quota, err = q.client.ResourceQuotas(usage.Namespace).Get(quota.Name)
if err != nil {
return admission.NewForbidden(a, err)
}
}
}
}
return nil
}
// IncrementUsage updates the supplied ResourceQuotaStatus object based on the incoming operation
// Return true if the usage must be recorded prior to admitting the new resource
// Return an error if the operation should not pass admission control
func IncrementUsage(a admission.Attributes, status *api.ResourceQuotaStatus, client client.Interface) (bool, error) {
var errs []error
dirty := true
set := map[api.ResourceName]bool{}
for k := range status.Hard {
set[k] = true
}
obj := a.GetObject()
// handle max counts for each kind of resource (pods, services, replicationControllers, etc.)
if a.GetOperation() == admission.Create {
resourceName := resourceToResourceName[a.GetResource()]
hard, hardFound := status.Hard[resourceName]
if hardFound {
used, usedFound := status.Used[resourceName]
if !usedFound {
return false, fmt.Errorf("quota usage stats are not yet known, unable to admit resource until an accurate count is completed.")
}
if used.Value() >= hard.Value() {
errs = append(errs, fmt.Errorf("limited to %s %s", hard.String(), resourceName))
dirty = false
} else {
status.Used[resourceName] = *resource.NewQuantity(used.Value()+int64(1), resource.DecimalSI)
}
}
}
if a.GetResource() == "pods" {
for _, resourceName := range []api.ResourceName{api.ResourceMemory, api.ResourceCPU} {
// ignore tracking the resource if it's not in the quota document
if !set[resourceName] {
continue
}
hard, hardFound := status.Hard[resourceName]
if !hardFound {
continue
}
// if we do not yet know how much of the current resource is used, we cannot accept any request
used, usedFound := status.Used[resourceName]
if !usedFound {
return false, fmt.Errorf("unable to admit pod until quota usage stats are calculated.")
}
// the amount of resource being requested, or an error if it does not make a request that is tracked
pod := obj.(*api.Pod)
delta, err := resourcequotacontroller.PodRequests(pod, resourceName)
if err != nil {
return false, fmt.Errorf("must make a non-zero request for %s since it is tracked by quota.", resourceName)
}
// if this operation is an update, we need to find the delta usage from the previous state
if a.GetOperation() == admission.Update {
oldPod, err := client.Pods(a.GetNamespace()).Get(pod.Name)
if err != nil {
return false, err
}
// if the previous version of the resource made a resource request, we need to subtract the old request
// from the current to get the actual resource request delta. if the previous version of the pod
// made no request on the resource, then we get an err value. we ignore the err value, and delta
// will just be equal to the total resource request on the pod since there is nothing to subtract.
oldRequest, err := resourcequotacontroller.PodRequests(oldPod, resourceName)
if err == nil {
err = delta.Sub(*oldRequest)
if err != nil {
return false, err
}
}
}
newUsage := used.Copy()
newUsage.Add(*delta)
// make the most precise comparison possible
newUsageValue := newUsage.Value()
hardUsageValue := hard.Value()
if newUsageValue <= resource.MaxMilliValue && hardUsageValue <= resource.MaxMilliValue {
newUsageValue = newUsage.MilliValue()
hardUsageValue = hard.MilliValue()
}
if newUsageValue > hardUsageValue {
errs = append(errs, fmt.Errorf("unable to admit pod without exceeding quota for resource %s: limited to %s but require %s to succeed.", resourceName, hard.String(), newUsage.String()))
dirty = false
} else {
status.Used[resourceName] = *newUsage
}
}
}
return dirty, errors.NewAggregate(errs)
}
func (s *serviceAccount) Admit(a admission.Attributes) (err error) {
if a.GetResource() != string(api.ResourcePods) {
return nil
}
obj := a.GetObject()
if obj == nil {
return nil
}
pod, ok := obj.(*api.Pod)
if !ok {
return nil
}
// Don't modify the spec of mirror pods.
// That makes the kubelet very angry and confused, and it immediately deletes the pod (because the spec doesn't match)
// That said, don't allow mirror pods to reference ServiceAccounts or SecretVolumeSources either
if _, isMirrorPod := pod.Annotations[kubelet.ConfigMirrorAnnotationKey]; isMirrorPod {
if len(pod.Spec.ServiceAccountName) != 0 {
return admission.NewForbidden(a, fmt.Errorf("A mirror pod may not reference service accounts"))
}
for _, volume := range pod.Spec.Volumes {
if volume.VolumeSource.Secret != nil {
return admission.NewForbidden(a, fmt.Errorf("A mirror pod may not reference secrets"))
}
}
return nil
}
// Set the default service account if needed
if len(pod.Spec.ServiceAccountName) == 0 {
pod.Spec.ServiceAccountName = DefaultServiceAccountName
}
// Ensure the referenced service account exists
serviceAccount, err := s.getServiceAccount(a.GetNamespace(), pod.Spec.ServiceAccountName)
if err != nil {
return admission.NewForbidden(a, fmt.Errorf("Error looking up service account %s/%s: %v", a.GetNamespace(), pod.Spec.ServiceAccountName, err))
}
if serviceAccount == nil {
// TODO: convert to a ServerTimeout error (or other error that sends a Retry-After header)
return admission.NewForbidden(a, fmt.Errorf("service account %s/%s was not found, retry after the service account is created", a.GetNamespace(), pod.Spec.ServiceAccountName))
}
if s.LimitSecretReferences {
if err := s.limitSecretReferences(serviceAccount, pod); err != nil {
return admission.NewForbidden(a, err)
}
}
if s.MountServiceAccountToken {
if err := s.mountServiceAccountToken(serviceAccount, pod); err != nil {
return admission.NewForbidden(a, err)
}
}
if len(pod.Spec.ImagePullSecrets) == 0 {
pod.Spec.ImagePullSecrets = make([]api.LocalObjectReference, len(serviceAccount.ImagePullSecrets))
copy(pod.Spec.ImagePullSecrets, serviceAccount.ImagePullSecrets)
}
return nil
}