Docker GUI is the easiest way to get off the ground.

You can find instructions to install docker on Installing Docker

At the end of the installation, you need to make sure you’re able to run the following command -

docker run hello-world

Docker let’s you do a lot of things.

It let’s you containerise your applications.

It let’s you run other people’s code + packages in your machine.

It let’s you run common software packages inside a container (For eg - Mongo, Postgres etc)

    Window/Mac Machine
     ____________________________________________________
    |                                                    |
    |                                                    |
    |       Container               Container            |
    |       ______________        ______________         |
    |      |              |      |              |        |
    |      |   MongoDB    |      |  Postgres    |        |
    |      |              |      |              |        |
    |      |    27017     |      |    5432      |        |
    |      |______________|      |______________|        |
    |                                                    |
    |____________________________________________________|

Let’s say you wan’t to run MongoDB locally Docker MongoDB

docker run mongo

You will notice you can’t open it in MongoDB Compass

The reason is that you haven’t added a port mapping

# docker run -p <local_port>:<container_port> mongo
docker run -p 27017:27017 mongo

The -d flag will run the container in the background

This will allow you to run the container and continue using the terminal for other commands.

docker run -d -p 27017:27017 mongo

This will show you all the containers you are running.

docker ps

Will stop the container that you are running

docker kill <container_id>

The connection string for this mongo would be

mongodb://localhost:27017

The connection string for this postgres would be

postgresql://postgres:mysecretpassword@localhost:5432/postgres