We will continue using ChartMuseum throughout the rest of the book, and I will leave it to you to decide whether Monocular is useful or a waste of computing resources.
We could have set up a container registry, but we didn't. There are too many tools in the market ranging from free solutions like Docker Registry (https://docs.docker.com/registry/) all the way until enterprise products like Docker Trusted Registry (https://docs.docker.com/ee/dtr/) and JFrog' Artifactory (https://www.jfrog.com/confluence/display/RTF/Docker+Registry). The problem is that Docker Registry (free version) is very insecure.
It provides only a very basic authentication. Still, the price is right (it's free). On the other hand, you might opt for one of the commercial solutions and leverage the additional features they provide. Never the less, I felt that for our use-case it is...