Containerizing and locally testing each application component

A best practice is to build Docker images using something called Dockerfiles. Dockerfile is a text file containing commands to build a Docker image layer by layer, starting with a base image. Our goal for the section will be to create two separate Dockerfiles. One Dockerfile is for the application and the other Dockerfile is for the database. Please note, Dockerfile default naming has no file extension by convention. So, be careful of text editors appending your Dockerfile with a .txt extension. If you are not familiar with Dockerfiles, please take minute to read this: https://docs.docker.com/engine/reference/builder/.