As you will remember from Chapter 1, Introduction to Docker, the Dockerfile is kind of a recipe to build an image. It's a plain text file containing instructions which are executed by Docker in the order they are placed. Each Dockerfile has a base image that the Docker engine will use to build upon. A resulting image will be a specific state of a file system: a read-only, frozen immutable snapshot of a live container, composed of layers representing changes in the filesystem at various points in time.
The image creation flow in Docker is pretty straightforward and consists basically of two steps:
- First, you prepare a text file named Dockerfile, which contains a series of instructions on how to build the image. The set of instructions ...
