Comment by jmholla

If the author is here, I think there's a typo in this. In section 1.4, you start working from the scratch layer, but the content continues to refer to alpine as the base layer.

    FROM scratch
    
    COPY ./hello /root/
    
    ENTRYPOINT ["./hello"]

> Here, our image contains 2 layers. The first layer comes from the base image, the alpine official docker image i.e. the root filesystem with all the standard shell tools that come along with an alpine distribution. Almost every instruction inside a Containerfile generates another layer. So in the Containerfile above, the COPY instruction creates the second layer which includes filesystem changes to the layer before it. The change here is “adding” a new file—the hello binary—to the existing filesystem i.e. the alpine root filesystem.