Always worked on projects where the docker-compose.yml already existed? Or your smart classmates made one for you? Daunted by the black magic that is Docker?

So was I. And if I can learn how to write one, so can you! (Did I miss a career in sales?)

Things you’ll need to have

• On a windows machine, like me, you need to have Docker Desktop installed.
• A project in your favourite IDE (I use IntelliJ IDEA).
• Patience

Things you’ll need to know

• Assuming you already know what Docker is and how to use it.
• Basic knowledge of YAML syntax We’ll figure that out as we go.

Anatomy

• services: = the containers you want to run.
• web: = name of the service.
• image: = which container image to use (here: Nginx).
• ports: = maps host:container → visit http://localhost:8080.
• docker compose up = runs the containers.
• docker compose down = stops and removes the containers.

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The bare minimum

Here’s the smallest working docker-compose.yml you can write:

version: "3.9"

services:
  web:
    image: nginx:latest
    ports:
      - "8080:80"

Now run: docker compose up and go to http://localhost:8080 in your browser. You should see the Nginx welcome page.

And BOOM — just like that, you did it.

Yes, you can now do black magic too.