6: Images
In this chapter we’ll dive deep into Docker images. The aim of the game is to give you a solid understanding of what Docker images are, how to perform basic operations, and how they work under-the-hood.
We’ll see how to build new images with our own applications inside of them in a later chapter.
We’ll split this chapter into the usual three parts:
- The TLDR
- The deep dive
- The commands
Docker images - The TLDR
A Docker image is a unit of packaging that contains everything required for an application to run. This includes; application code, application dependencies, and OS constructs. If you have an application’s Docker image, the only other thing you need to run that application is a computer running Docker.
If you’re a former VM admin, you can think of Docker images as similar to VM templates. A VM template is like a stopped VM — a Docker image is like a stopped container. If you’re a developer you can think of...