State Preservation

Having a system without a state is impossible. Even though there is a tendency to develop stateless applications, we still need to deal with the state. There are databases and other stateful third-party applications. No matter what we do, we need to make sure that the state is preserved no matter what happens to containers, Pods, or even whole nodes.

Most of the time, stateful applications store their state on disk. That leaves us with a problem. If a container crashes, kubelet will restart it. The problem is that it will create a new container based on the same image. All data accumulated inside a container that ...