> I can't believe the number of people I've seen running practically whole operating systems inside a container. What's wrong with this? I mean, technically,

> I can't believe the number of people I've seen running practically whole operating systems inside a container. What's wrong with this? I mean, technically, all containers are all about running the entire userland of an operating system; it just happens that we usually use very small values of "operating system" when we do this. If you run a proper init system inside the container, you don't have to deal with the issues that come from having orphaned processes inside containers. And this ends up being a far more meaningful way of encapsulating components that are tightly linked into a single high-level unit. The only reason that this is an antipattern with Docker is that the Docker runtime doesn't properly handle a lot of things like signal handling or process monitoring for non-init processes, which means you have to reinvent the wheel if you want to have multiple applications running reliably in a container. But that's a limitation of Docker specifically (and one that will hopefully be solved), rather than a fundamental premise of containers in general.