Get a docker endpoint, either from the string passed in, or $DOCKER_HOST environment variables.

RunApiServer starts an API server in a go routine.

RunControllerManager starts a controller.

RunKubelet is responsible for setting up and running a kubelet.

RunScheduler starts up a scheduler in it's own goroutine.

SimpleRunKubelet is a simple way to start a Kubelet talking to dockerEndpoint, using an etcdClient.