Learning the basics of Docker

We learned about Docker concepts in Chapter 1, Journey to the Spring World. Now, it is time to test our knowledge and put it into practice. In the first part of this chapter, we will start MongoDB and Postgres instances to serve as a database for our application. We will configure connection settings in the application.

In the last part of this chapter, we will introduce the Maven plugin which provides an easy way to create Docker images via pom.xml with a couple of configurations on file. Finally, we will run our application in a Docker container. 

Preparing  MongoDB

Let's create our MongoDB container. We will use the official image provided by the Docker Hub.

First, we need to pull the image:

docker pull mongo:3.4.10

Then, we will see the Docker Engine downloading the image contents.

To create an isolation from our containers, we will create a separated network for our application and database. The network should use the bridge driver to allow the container communications...