How to: How do I rollback a Deployment?
If you apply a change to a Deployment with the `--record` flag then Kubernetes stores the previous Deployment in its history. The `kubectl rollout history deployment
` command will show prior Deployments. The last Deployment can be restored with the `kubectl rollout undo deployment
` command. In progress Deployments can also be paused and resumed. 

When a new version of a Deployment is applied, a new ReplicaSet object is created which is slowly scaled up while the old ReplicaSet is scaled down. You can look at each ReplicaSet that has been rolled out with `kubectl get replicaset`. Each ReplicaSet is named with the format
-
, so you can also do `kubectl describe replicaset
`.

Learn more: http://kubernetes.io/docs/user-guide/kubectl/kubectl_rollout/