This exam closes the "Discover Docker and run a container" module of the Docker course. You arrive on a host where Docker is installed but nothing works as it should, and you must get it running again on your own, with no hints, using what the lessons of the module taught you. It teaches you nothing new, it checks what you have learned. Allow about 30 minutes on a virtual machine running Docker Engine 29.9.2.
What you will learn
- Say what the exam provides, what it expects and what it grades you on.
- Spot the lessons to review before you start.
- Read your result to decide whether to move on to the next module or to consolidate.
Prerequisites
The four lessons of the "Discover Docker and run a container" module must be finished, up to the last one, Run a Docker container and choose what it runs. The exam assumes that you know how to check the state of the engine, run, name and remove a container, configure it through an environment variable and say what its arguments replace.
Use the lab environment you used for the previous lessons. The exam asks you to build nothing: the image is provided.
What does the exam ask of you?
The statement describes the state of the machine to hand back: the engine running, and durably so, your account talking to it without going through sudo, a service started from the provided image with the requested configuration, another container kept exactly as it is, and a small prediction file written before running the command concerned. These requirements are not all met by the same action.
Nobody tells you where to look. Checking the starting state is therefore part of the exam, just as much as fixing it. This page does not describe the scenario, so that the exam stays a measurement. You will read it in the lab statement, and only there.
How is it graded?
The lab does not look at the commands you typed. It reads back the state of the system at the moment you hand in your work: the state of the engine, the groups of your account, the containers present, the response of the service and the content of your prediction file. One of the checks even recreates a container itself, without starting it, to compare your prediction with what the engine retains. Two different paths that end in the same state get the same grade.
Five checks of equal weight share the grade, and you must reach 75 points to pass. The grade is the number of checks passed divided by five, multiplied by a scale of 100 points minus the cost of the hints you asked for.
A critical requirement comes on top of the threshold: the container to keep must stay present, stay stopped and keep its logs readable. Removing it, restarting it or losing its logs fails the exam, even with everything else in place, because no total makes up for a destroyed piece.
With no hint, four checks passed out of five give 80 points and clear the threshold, provided the critical requirement is met. Each hint lowers the maximum you can reach:
| Hints requested | Scale | Checks to pass |
|---|---|---|
| None | 100 | 4 out of 5 (80 points) |
| The first | 90 | 5 out of 5 (4 out of 5 give 72) |
| The first two | 75 | 5 out of 5 |
| Three or more | 55 at most | Threshold not reachable |
Which rules apply?
This exam measures, it does not guide you. Three rules follow from that.
- The lab offers four hints, from the vaguest to the most explicit, and each one costs you points, from 10 for the first to 25 for the last. With two hints, you must pass all five checks; beyond two, the threshold is no longer reachable. An exam passed without a hint is therefore passed in full.
- You may consult the lessons of the course and the official Docker documentation, as you would at work.
- The statement explains nothing again, because the lessons of the module have already taught what you need to know.
If you are stuck, read before you act. A message or a state often tells you where you stand. An action that cannot be undone is decided after reading the statement to the end.
Which lessons should you review before starting?
The statement does not say which actions it asks for, and this list does not try to point them out either. It gathers, in the order of the course, the lessons of the module that teach an action useful here. Start by rereading those where your last labs were difficult.
- Images, containers and registries: the anatomy
- Install Docker Engine 29 and prove it works
- Run a Docker container and choose what it runs
Take the exam
The lab prepares the machine, gives you the statement, then grades the state in which you leave it. Start it when you have about 30 minutes ahead of you, so that you can work in one go.
After the exam
If you pass the threshold with the critical requirement met, you can bring a Docker host back into working order, run a configured service and keep what you are asked to keep, on your own, on the points measured. You can move on to the next module. A result under the threshold does not mean that you failed to learn. It shows where the gap is.
The messages of the checks describe the symptom observed, not the action to take. It is up to you to link each failed check to a lesson in the list above, to reread it, then to redo the action yourself. Do not try to memorize an answer.
Key points
- The exam is a measurement. Nothing is explained again, hints cost points and the grade covers the final state of the system.
- You need 75 points to pass, and the container to keep must stay present, stopped and readable: otherwise the exam is refused whatever the total.
- A service that runs now and a service that will come back at the next boot are two different facts.
- What looks like an obstacle is not always to be removed: read the statement before cleaning up.
- To close a gap, reread the matching lesson, then redo the action.