You would bring up a 2nd container with the new code, map the traffic to this container, and once you are sure it is good, trash the old container. If there is

You would bring up a 2nd container with the new code, map the traffic to this container, and once you are sure it is good, trash the old container. If there is a problem with the new code, just point the traffic back to the working container and kill the new container.