Chapter02

Question 1

What is a container image ?

Answer 1

A container image is a binary package that encapsulates all of the files necessary to run a program inside of an OS container.

Question 2

Container images are typically combined with…

Answer 2

A container configuration file, which provides instructions of how to set up the container environment and execute the application entry point.
The container configuration often includes information on how to set up networking, namespace isolation, resource constraints (cgroups), and what syscall restrictions should be placed on a running container instance. The container root filesystem and configuration file are typically bundled using the Docker image format.

Question 3

Which categories containers can be grouped ?

Answer 3

• System containers

- Application containers

Question 4

What are system containers ?

Answer 4

Systems containers seek to mimic virtual machines and often run a full boot process. They often include a set of system services typically found in VM, such as ssh, cron and syslog.

Question 5

What are application containers ?

Answer 5

Application containers commonly run a single program. While running a single program per container might seem like an unnecessary constraint, it provides the perfect level of granularity for composing scalable applications and is a design philosophy that is leveraged heavily by Pods.