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.

Let's create a docker network:

docker network create cms-application

The command output should be an ID of a created network. Your ID will probably be different compared to mine:

To check if the network was created successfully, the docker network ls command can help us.

We will start our MongoDB. The network should be cms-application, but we will map the database port to a host port. For debugging purposes, we will connect a client to a running database, but please don't do this in a non-development environment.

To start, type the following command:

docker run -d --name mongodb --net cms-application -p 27017:27017 mongo:3.4.10

The output will be a hash which represents the ID of the container.

The parameter instructions are:

• -d: This instructs Docker to run the container in a background mode
• --name: The container name; it will be a kind of hostname in our network
• --net: The network where the container will be attached
• -p: The host port and container port, which will be mapped to a container on a host interface

Now, we have a pretty standard MongoDB instance running on our machines, and we can start to add a persistence in our CMS application. We will do that soon.