Multistage Docker Builds

[JoshLoecker]

The use of multistage builds can greatly reduce the size of the final docker image. See below.

DockerHub Page to Multistage Builds

One of the most challenging things about building images is keeping the image size down. Each instruction in the Dockerfile adds a layer to the image, and you need to remember to clean up any artifacts you don’t need before moving on to the next layer. To write a really efficient Dockerfile, you have traditionally needed to employ shell tricks and other logic to keep the layers as small as possible and to ensure that each layer has the artifacts it needs from the previous layer and nothing else.

It was actually very common to have one Dockerfile to use for development (which contained everything needed to build your application), and a slimmed-down one to use for production, which only contained your application and exactly what was needed to run it. This has been referred to as the “builder pattern”. Maintaining two Dockerfiles is not ideal.

Additional Links
How to Optimize Docker Images using Dive
How do I 'copy' installed R-packages from the 1ste stage to 2nd stage using multistage building on a R-base image?