Building Microservices with Go

Good practice for creating Dockerfiles

Taking all of this into account, we need to remember how the union file system works in Docker and how we can leverage it to create small and compact images. Every time we issue a command in the Dockerfile, Docker will create a new layer. When we mutate this command, the layer must be completely recreated and potentially all the following layers too, which can dramatically slow down your build. It is therefore recommended a good practice that you should attempt to group your commands as tightly as possible to reduce the possibility of this occurring.

Quite often, you will see Dockerfiles which instead of having a separate RUN command for every command we would like to execute, we chain these using standard ...