// updateRcWithRetries retries updating the given rc on conflict with the following steps:
// 1. Get latest resource
// 2. applyUpdate
// 3. Update the resource
func updateRcWithRetries(c client.Interface, namespace string, rc *api.ReplicationController, applyUpdate updateRcFunc) (*api.ReplicationController, error) {
// Deep copy the rc in case we failed on Get during retry loop
obj, err := api.Scheme.Copy(rc)
if err != nil {
return nil, fmt.Errorf("failed to deep copy rc before updating it: %v", err)
}
oldRc := obj.(*api.ReplicationController)
err = client.RetryOnConflict(client.DefaultBackoff, func() (e error) {
// Apply the update, then attempt to push it to the apiserver.
applyUpdate(rc)
if rc, e = c.ReplicationControllers(namespace).Update(rc); e == nil {
// rc contains the latest controller post update
return
}
updateErr := e
// Update the controller with the latest resource version, if the update failed we
// can't trust rc so use oldRc.Name.
if rc, e = c.ReplicationControllers(namespace).Get(oldRc.Name); e != nil {
// The Get failed: Value in rc cannot be trusted.
rc = oldRc
}
// Only return the error from update
return updateErr
})
// If the error is non-nil the returned controller cannot be trusted, if it is nil, the returned
// controller contains the applied update.
return rc, err
}
func GetServerVersion(w io.Writer, kubeClient client.Interface) {
serverVersion, err := kubeClient.Discovery().ServerVersion()
if err != nil {
fmt.Printf("Couldn't read server version from server: %v\n", err)
os.Exit(1)
}
fmt.Fprintf(w, "Server Version: %#v\n", *serverVersion)
}
func CreateNewControllerFromCurrentController(c client.Interface, codec runtime.Codec, cfg *NewControllerConfig) (*api.ReplicationController, error) {
containerIndex := 0
// load the old RC into the "new" RC
newRc, err := c.ReplicationControllers(cfg.Namespace).Get(cfg.OldName)
if err != nil {
return nil, err
}
if len(cfg.Container) != 0 {
containerFound := false
for i, c := range newRc.Spec.Template.Spec.Containers {
if c.Name == cfg.Container {
containerIndex = i
containerFound = true
break
}
}
if !containerFound {
return nil, fmt.Errorf("container %s not found in pod", cfg.Container)
}
}
if len(newRc.Spec.Template.Spec.Containers) > 1 && len(cfg.Container) == 0 {
return nil, goerrors.New("Must specify container to update when updating a multi-container pod")
}
if len(newRc.Spec.Template.Spec.Containers) == 0 {
return nil, goerrors.New(fmt.Sprintf("Pod has no containers! (%v)", newRc))
}
newRc.Spec.Template.Spec.Containers[containerIndex].Image = cfg.Image
if len(cfg.PullPolicy) != 0 {
newRc.Spec.Template.Spec.Containers[containerIndex].ImagePullPolicy = cfg.PullPolicy
}
newHash, err := api.HashObject(newRc, codec)
if err != nil {
return nil, err
}
if len(cfg.NewName) == 0 {
cfg.NewName = fmt.Sprintf("%s-%s", newRc.Name, newHash)
}
newRc.Name = cfg.NewName
newRc.Spec.Selector[cfg.DeploymentKey] = newHash
newRc.Spec.Template.Labels[cfg.DeploymentKey] = newHash
// Clear resource version after hashing so that identical updates get different hashes.
newRc.ResourceVersion = ""
return newRc, nil
}
// updatePodWithRetries retries updating the given pod on conflict with the following steps:
// 1. Get latest resource
// 2. applyUpdate
// 3. Update the resource
func updatePodWithRetries(c client.Interface, namespace string, pod *api.Pod, applyUpdate updatePodFunc) (*api.Pod, error) {
// Deep copy the pod in case we failed on Get during retry loop
obj, err := api.Scheme.Copy(pod)
if err != nil {
return nil, fmt.Errorf("failed to deep copy pod before updating it: %v", err)
}
oldPod := obj.(*api.Pod)
err = client.RetryOnConflict(client.DefaultBackoff, func() (e error) {
// Apply the update, then attempt to push it to the apiserver.
applyUpdate(pod)
if pod, e = c.Pods(namespace).Update(pod); e == nil {
return
}
updateErr := e
if pod, e = c.Pods(namespace).Get(oldPod.Name); e != nil {
pod = oldPod
}
// Only return the error from update
return updateErr
})
// If the error is non-nil the returned pod cannot be trusted, if it is nil, the returned
// controller contains the applied update.
return pod, err
}
func AddDeploymentKeyToReplicationController(oldRc *api.ReplicationController, client client.Interface, deploymentKey, deploymentValue, namespace string, out io.Writer) (*api.ReplicationController, error) {
var err error
// First, update the template label. This ensures that any newly created pods will have the new label
applyUpdate := func(rc *api.ReplicationController) {
if rc.Spec.Template.Labels == nil {
rc.Spec.Template.Labels = map[string]string{}
}
rc.Spec.Template.Labels[deploymentKey] = deploymentValue
}
if oldRc, err = updateRcWithRetries(client, namespace, oldRc, applyUpdate); err != nil {
return nil, err
}
// Update all pods managed by the rc to have the new hash label, so they are correctly adopted
// TODO: extract the code from the label command and re-use it here.
selector := labels.SelectorFromSet(oldRc.Spec.Selector)
options := api.ListOptions{LabelSelector: selector}
podList, err := client.Pods(namespace).List(options)
if err != nil {
return nil, err
}
for ix := range podList.Items {
pod := &podList.Items[ix]
applyUpdate := func(p *api.Pod) {
if p.Labels == nil {
p.Labels = map[string]string{
deploymentKey: deploymentValue,
}
} else {
p.Labels[deploymentKey] = deploymentValue
}
}
if pod, err = updatePodWithRetries(client, namespace, pod, applyUpdate); err != nil {
return nil, err
}
}
if oldRc.Spec.Selector == nil {
oldRc.Spec.Selector = map[string]string{}
}
// Copy the old selector, so that we can scrub out any orphaned pods
selectorCopy := map[string]string{}
for k, v := range oldRc.Spec.Selector {
selectorCopy[k] = v
}
applyUpdate = func(rc *api.ReplicationController) {
rc.Spec.Selector[deploymentKey] = deploymentValue
}
// Update the selector of the rc so it manages all the pods we updated above
if oldRc, err = updateRcWithRetries(client, namespace, oldRc, applyUpdate); err != nil {
return nil, err
}
// Clean up any orphaned pods that don't have the new label, this can happen if the rc manager
// doesn't see the update to its pod template and creates a new pod with the old labels after
// we've finished re-adopting existing pods to the rc.
selector = labels.SelectorFromSet(selectorCopy)
options = api.ListOptions{LabelSelector: selector}
podList, err = client.Pods(namespace).List(options)
for ix := range podList.Items {
pod := &podList.Items[ix]
if value, found := pod.Labels[deploymentKey]; !found || value != deploymentValue {
if err := client.Pods(namespace).Delete(pod.Name, nil); err != nil {
return nil, err
}
}
}
return oldRc, nil
}