Chapter 1

1. b and c: We can run more than one process per container, but it is not recommended because Docker Engine will only manage the main container process. We will need to manage additional logic between processes to start and stop everything at once. It is not easy and you can leave "zombie" processes in your hosts. Microservices are based on minimal functionality for each application component, which fits with containers very well.
2. b: Control groups, or cgroups, will manage the host resources provided to each container, but it is very important to understand that, by default, containers will run with unlimited resources.
3. a and b: Containers will run as root unless the source image has a non-root user definition or we specify a non-root user upon container creation. User namespaces allow us to use the root inside containers, although a real user outside the container can have a non-root ID. This is useful when processes require UID 0 to work.
4. d. All of the above sentences...