I’m having trouble getting my head wrapped around this…
If I have a Docker Engine running in Ubuntu and then I build a Dockerfile with something like this:
RUN yum -y update && yum -y install
What exactly is going to happen here? Is it going to build a centos layer(s) that essentially contains diffs between the centos base and Ubuntu where the Engine is running? And then another layer(s) for the Apache package install?
Even though this works, would this be frowned upon…or not really since the objective is a Docker image should run in any Docker engine, regardless of the base Linux OS?