Creating a minimal image using a scratch base image

In the previous recipe, we custom-created a base image without any parent image. However, that image is bloated with all the binaries and libraries that are shipped with the Ubuntu 18.04 distribution. Typically, to run an application, we don't need the majority of the binaries and libraries we have bundled in the image. Besides, it leaves a large image footprint, and thus becomes a portability problem. To overcome this issue, you can diligently hand-pick the binaries and libraries that will constitute your image and then bundle the Docker image. Alternatively, you can build using Docker's reserved image, called a scratch image. This scratch image is explicitly an empty image, and it does not add any additional layer to your image. Furthermore, unlike the previous recipe, you can automate image creation using a Dockerfile...