[tra3]

I want to discuss your last point. With Docker, you are free to either modify the image or the running container. An image is a "template" for a container and in the scenario you describe, the ideal solution is to create a new image because it can be potentially running on multiple nodes. However, nothing prevents you from accessing the container (no SSH required) and modifying the container in place. Although I do believe it is discouraged.

Thanks for the SmartOS reference, it looks very interesting.