// Update performs a rolling update of a collection of pods.
// 'name' points to a replication controller.
// 'client' is used for updating pods.
// 'updatePeriod' is the time between pod updates.
func Update(name string, client client.Interface, updatePeriod time.Duration) error {
controller, err := client.GetReplicationController(name)
if err != nil {
return err
}
s := labels.Set(controller.DesiredState.ReplicaSelector).AsSelector()
podList, err := client.ListPods(s)
if err != nil {
return err
}
expected := len(podList.Items)
if expected == 0 {
return nil
}
for _, pod := range podList.Items {
// We delete the pod here, the controller will recreate it. This will result in pulling
// a new Docker image. This isn't a full "update" but it's what we support for now.
err = client.DeletePod(pod.ID)
if err != nil {
return err
}
time.Sleep(updatePeriod)
}
return wait.Poll(time.Second*5, time.Second*300, func() (bool, error) {
podList, err := client.ListPods(s)
if err != nil {
return false, err
}
return len(podList.Items) == expected, nil
})
}