The workflow for creating automated Docker builds from Git

Building local containers is a nice thing to do, but what about its wide distribution? We can use the Docker Hub service to store and distribute our containers (or its alternative Quay.io); however, uploading each and every container and version manually will soon be a problem. Consider you need to rebuild dozens of containers in an emergency, because of the existence of another OpenSSL security bug; nobody would want to be the one to upload them one by one, especially with the bad uplink at work. And as we're working with our Docker code using branches and tags, it will be awesome to see the same behavior reflected automatically on the remote Docker registry. This includes two of the Docker Hub (or Quay.io) features: automatically build Docker images upon changes and serve them to the world. We'll do exactly this in this section: create an automated build and distribution pipeline from our code to GitHub to the Docker...