World D0: Start Here

Placement test

You will learn: which Docker lessons you can skip, because you know them already.

Checked with Docker Engine 29 on 31 Oct 2026

The problem

Maybe you know some Docker already. Why sit through lessons you don’t need? Warm-up first: what does a container carry?

Watch

Tap each point on the timeline.

Here is how it works. Not sure about a question? Tap “I don’t know yet”. Tap each step first.

Try it

Every right answer ticks a lesson you may skip.

Answer what you can. Skip what you don't know. No pressure.

Question 1 of 18

You type docker run nginx:1.30-alpine. The image is not on your laptop. What happens?

Check

A lesson got a tick. Can you still open it?

Try it

Last D0 recap. Which crash course explains each real error?

Drag a card into a box. Or tap the card, then tap the box.

You did it!

You can now skip what you know and jump straight to what is new.

Go deeper (optional)

Where the story breaks. A container is not sealed like a lunchbox: it shares the laptop’s kernel. A port is not a real hatch, just a number software listens on. And YAML can nest far deeper than any tiffin carrier.

Real rep: next, the boss. Set up your real kitchen.