Exam essentials

This chapter doesn’t map directly to an exam domain. However, the following exam topics were mentioned and will be covered in more detail later in the book.

Container runtimes

A server that runs containers is called a container host. They use a low-level tool called a container runtime to start and stop containers. Docker is the best-known container runtime and was the first container runtime supported by Kubernetes. However, it is being replaced in Kubernetes by a lighter-weight version called containerd (pronounced “container dee”). Many other container runtimes exist and some of them work differently. Some offer better performance at the expense of security, whereas others offer better security at the expense of size and performance. You’ll learn more later in the book.

Container security

All containers running on a single host share the host’s OS kernel. This makes them small, portable, and fast to start. However, if the...