How to create a preemptable docker container?
I'm not aware of any straightforward way to do that, without also running a different container to act as a middleware of sorts. You might want to look at one of the "Serverless" platforms. If your use case will fit that model, many of the docker/swarm/kubernetes serverless tools do what you're asking, but again, you're running other container(s) to manage it. I'd suggest starting with a glance at the OpenFAAS docs to see if it'll work for you.