// UpdateRSWithRetries updates a RS with given applyUpdate function. Note that RS not found error is ignored.
// The returned bool value can be used to tell if the RS is actually updated.
func UpdateRSWithRetries(rsClient unversionedextensions.ReplicaSetInterface, rsLister *cache.StoreToReplicaSetLister, namespace, name string, applyUpdate updateRSFunc) (*extensions.ReplicaSet, error) {
var rs *extensions.ReplicaSet
retryErr := retry.RetryOnConflict(retry.DefaultBackoff, func() error {
var err error
rs, err = rsLister.ReplicaSets(namespace).Get(name)
if err != nil {
return err
}
obj, deepCopyErr := api.Scheme.DeepCopy(rs)
if deepCopyErr != nil {
return deepCopyErr
}
rs = obj.(*extensions.ReplicaSet)
// Apply the update, then attempt to push it to the apiserver.
if applyErr := applyUpdate(rs); applyErr != nil {
return applyErr
}
rs, err = rsClient.Update(rs)
return err
})
// Ignore the precondition violated error, but the RS isn't updated.
if retryErr == errorsutil.ErrPreconditionViolated {
glog.V(4).Infof("Replica set %s/%s precondition doesn't hold, skip updating it.", namespace, name)
retryErr = nil
}
return rs, retryErr
}
// updateReplicaSetStatus attempts to update the Status.Replicas of the given ReplicaSet, with a single GET/PUT retry.
func updateReplicaSetStatus(c unversionedextensions.ReplicaSetInterface, rs extensions.ReplicaSet, newStatus extensions.ReplicaSetStatus) (updateErr error) {
// This is the steady state. It happens when the ReplicaSet doesn't have any expectations, since
// we do a periodic relist every 30s. If the generations differ but the replicas are
// the same, a caller might've resized to the same replica count.
if rs.Status.Replicas == newStatus.Replicas &&
rs.Status.FullyLabeledReplicas == newStatus.FullyLabeledReplicas &&
rs.Status.ReadyReplicas == newStatus.ReadyReplicas &&
rs.Status.AvailableReplicas == newStatus.AvailableReplicas &&
rs.Generation == rs.Status.ObservedGeneration &&
reflect.DeepEqual(rs.Status.Conditions, newStatus.Conditions) {
return nil
}
// deep copy to avoid mutation now.
// TODO this method need some work. Retry on conflict probably, though I suspect this is stomping status to something it probably shouldn't
copyObj, err := api.Scheme.DeepCopy(&rs)
if err != nil {
return err
}
rs = *copyObj.(*extensions.ReplicaSet)
// Save the generation number we acted on, otherwise we might wrongfully indicate
// that we've seen a spec update when we retry.
// TODO: This can clobber an update if we allow multiple agents to write to the
// same status.
newStatus.ObservedGeneration = rs.Generation
var getErr error
for i, rs := 0, &rs; ; i++ {
glog.V(4).Infof(fmt.Sprintf("Updating replica count for ReplicaSet: %s/%s, ", rs.Namespace, rs.Name) +
fmt.Sprintf("replicas %d->%d (need %d), ", rs.Status.Replicas, newStatus.Replicas, *(rs.Spec.Replicas)) +
fmt.Sprintf("fullyLabeledReplicas %d->%d, ", rs.Status.FullyLabeledReplicas, newStatus.FullyLabeledReplicas) +
fmt.Sprintf("readyReplicas %d->%d, ", rs.Status.ReadyReplicas, newStatus.ReadyReplicas) +
fmt.Sprintf("availableReplicas %d->%d, ", rs.Status.AvailableReplicas, newStatus.AvailableReplicas) +
fmt.Sprintf("sequence No: %v->%v", rs.Status.ObservedGeneration, newStatus.ObservedGeneration))
rs.Status = newStatus
_, updateErr = c.UpdateStatus(rs)
if updateErr == nil || i >= statusUpdateRetries {
return updateErr
}
// Update the ReplicaSet with the latest resource version for the next poll
if rs, getErr = c.Get(rs.Name, metav1.GetOptions{}); getErr != nil {
// If the GET fails we can't trust status.Replicas anymore. This error
// is bound to be more interesting than the update failure.
return getErr
}
}
}