Understanding containers

So, to kick off this chapter, let’s provide a quick overview of what a container is and why they are all the rage. In this chapter, I don’t want to get into the specifics of the inner workings of containers, but in short, you can think of them as very lightweight and portable virtual machines or machine images but only in the sense of starting multiple instances of an application. From an inner-workings standpoint, containers more closely resemble a single server with multiple processes running. A typical virtual machine with all the OS components can easily be a couple of gigabytes – and in the case of Windows images, upward of 10, 20, 30, or more gigabytes. A container’s size can usually be measured in megabytes. Most containers share the resources of their host OS and only contain the libraries they need to run their application. Another notable benefit is how quickly they can launch. When you boot a full computer image, you usually...