Defined start sequence of containers
https://forums.rancher.com/t/start-order-of-stack-containers/3106/9


  We do not support depends_on, and neither does Docker in Swarm mode.
  It is not a real solution to the problem anyway and leaves you with
  unhandled pointy-edge cases when failures occur and containers are
  being replaced. Your services should know how to either wait for their
  dependencies or exit and be rescheduled to retry.


I agree with this comment. Services should always be able to start. Imagine that one service goes down then another service will not work anymore.