Support docker swarm

[sargreal]

Docker swarm is an alternative/ more scalable container orchestration than docker-compose. It should also be supported with corresponding utilities.

It is currently only possible to stop containers. Possible additions for docker swarm or also in general are:

• execute job in container (for example set maintenance mode or execute backup utility in the container)
• scale service

Passcodes are currently stored in environment variables. It should also be possible to use _FILE environment variables

[sargreal]

Support for docker swarm now includes:

• utility to get task of service
• enable file_env variables for passwords and targets

Scaling and directly executing is not included because of unusefulness with cli options

[dreadedhamish]

Is there documentation for this? Does "utility to get task of service" overcome the issue of not being able to stop and start containers using VOLUMERIZE_CONTAINERS because swarm adds a hash to the container name which is unpredictable?