How to control multiple docker hosts?

Question

Docker

Good afternoon!
There is a task to lease application. Each client has their own copy.
As a solution - docker or rkt containers. There are several servers in different parts of the world. The application is issued strictly one client - one copy. The container is started, stopped and reloaded at the request of the client by the client through the web muzzle.
1. Question: how best to organize this business? How to control many docker hosts from one server?
I tried docker-machine, it seems to be enough, because it configures docker hosts itself and makes it possible to work with remote docker daemons via an API with certificates. But docker-machine looks like a developer tool, not a tool to control different docker servers.
2. And a bunch of questions. The application works with a database file. It reads it at the start, writes at the end. It must somehow be driven into the container before launching and taken away at the end of the container. The file must be taken from a certain storage and put into the same storage, and preferably with backups. To do this, I wrote a bash script that seems to work and even manages to zip this database file. But is there any solution that allows you to mount some kind of storage from a remote source into a container, which then automatically flies back to the same remote source and also so that there is versioning?