This a very quick walkthrough of spinning up a mongodb server inside a docker container and connecting with it through the mongodb compass gui.

Why would you wanna do this?

• You wanna get rid of MongoDB Atlas

• You want a FREE solution

• You want autonomy over how to manage and deploy your server

Pre-requisites:

• Basic understanding of how to run a docker image

• Basic understanding of what MongoDB is.

For when you just need to spin up a quick MongoDB server don't want to spin up a MongoDB Atlas instance (Ugh, sign up, login, spin up a server and wait for it to get ready. It's a hassle)

Docker allows to quickly spin up a server ad-hoc without needing to sign up on any service and pay for any service. All you need is to have docker installed on your machine and internet connection (to download the mongodb image from the doker registry).

How to run docker inside a container

Once you have both, here's how you set it up. Firstly, open up the terminal and type the following command

docker run --name mongodbcontainer -p 27017:27017 -e MONGO_INITDB_ROOT_USERNAME=mongodbrootusername -e MONGO_INITDB_ROOT_PASSWORD=mongodbrootpassword -d mongo

In the above command,
1. "-p" denotes port. Left side denotes the port on YOUR COMPUTER and right side denotes port to listen to INSIDE DOCKER CONTAINER

2. "-e" denotes environment variables

3. "-d" denotes daemon mode, ie the process will run in the background and not take up your terminal

4. "--name" denotes the name that you can assign to the container

Connect MongoDB inside container to your app

Once you've run this command, it will spin up a mongodb server inside a docker container. To connect to that container from a (for example, nodejs) app, here's the connection string you must enter.

mongodb://mongodbrootusername:mongodbrootpassword@localhost:27017/?retryWrites=true&w=majority

And that's that. You are now conneted to an instance of MongoDB running inside a container on your machine.