// Returns the old RCs targetted by the given Deployment.
func GetOldRCs(deployment extensions.Deployment, c client.Interface) ([]*api.ReplicationController, error) {
namespace := deployment.ObjectMeta.Namespace
// 1. Find all pods whose labels match deployment.Spec.Selector
podList, err := c.Pods(namespace).List(labels.SelectorFromSet(deployment.Spec.Selector), fields.Everything())
if err != nil {
return nil, fmt.Errorf("error listing pods: %v", err)
}
// 2. Find the corresponding RCs for pods in podList.
// TODO: Right now we list all RCs and then filter. We should add an API for this.
oldRCs := map[string]api.ReplicationController{}
rcList, err := c.ReplicationControllers(namespace).List(labels.Everything())
if err != nil {
return nil, fmt.Errorf("error listing replication controllers: %v", err)
}
for _, pod := range podList.Items {
podLabelsSelector := labels.Set(pod.ObjectMeta.Labels)
for _, rc := range rcList.Items {
rcLabelsSelector := labels.SelectorFromSet(rc.Spec.Selector)
if rcLabelsSelector.Matches(podLabelsSelector) {
// Filter out RC that has the same pod template spec as the deployment - that is the new RC.
if api.Semantic.DeepEqual(rc.Spec.Template, GetNewRCTemplate(deployment)) {
continue
}
oldRCs[rc.ObjectMeta.Name] = rc
}
}
}
requiredRCs := []*api.ReplicationController{}
for _, value := range oldRCs {
requiredRCs = append(requiredRCs, &value)
}
return requiredRCs, nil
}
// Returns an RC that matches the intent of the given deployment.
// Returns nil if the new RC doesnt exist yet.
func GetNewRC(deployment extensions.Deployment, c client.Interface) (*api.ReplicationController, error) {
namespace := deployment.ObjectMeta.Namespace
rcList, err := c.ReplicationControllers(namespace).List(labels.Everything())
if err != nil {
return nil, fmt.Errorf("error listing replication controllers: %v", err)
}
newRCTemplate := GetNewRCTemplate(deployment)
for _, rc := range rcList.Items {
if api.Semantic.DeepEqual(rc.Spec.Template, newRCTemplate) {
// This is the new RC.
return &rc, nil
}
}
// new RC does not exist.
return nil, nil
}