// 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
})
}
// DeleteController deletes a replication controller named 'name', requires that the controller
// already be stopped
func DeleteController(name string, client client.Interface) error {
controller, err := client.GetReplicationController(name)
if err != nil {
return err
}
if controller.DesiredState.Replicas != 0 {
return fmt.Errorf("controller has non-zero replicas (%d), please stop it first", controller.DesiredState.Replicas)
}
return client.DeleteReplicationController(name)
}
// ResizeController resizes a controller named 'name' by setting replicas to 'replicas'
func ResizeController(name string, replicas int, client client.Interface) error {
controller, err := client.GetReplicationController(name)
if err != nil {
return err
}
controller.DesiredState.Replicas = replicas
controllerOut, err := client.UpdateReplicationController(controller)
if err != nil {
return err
}
data, err := yaml.Marshal(controllerOut)
if err != nil {
return err
}
fmt.Print(string(data))
return nil
}