Module · DevOps Engineer

Docker

Build, run, inspect and debug containers.

6 topics7 interactive tasks

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TOPIC 01

Containers & Images

Images, layers, running containers and inspecting what they do.

What you'll practice

Deploy the Application as a Container — challenge · intermediate

A command you'll meet

docker images

Open any task below to get the full step-by-step walkthrough — every command is explained, and the lab validator checks what you actually built.

Hands-On Tasks in This Topic (1)

intermediate

Challenge

Deploy the Application as a Container

A simple HTTP application image (app:latest) is already pulled on this machine. Deploy it as a container so it is reachable on port 8080. The walkthrough shows the exact commands and what every flag does.

Environment: docker:24Launch Lab ⚡

TOPIC 02

Building Images

Dockerfiles, build contexts and tagging.

What you'll practice

Build Your Own Image — guided · beginner

A command you'll meet

mkdir ~/build

Open any task below to get the full step-by-step walkthrough — every command is explained, and the lab validator checks what you actually built.

Hands-On Tasks in This Topic (1)

beginner

Guided Task

Build Your Own Image

Instead of consuming images, make one. Write a Dockerfile, build it with a tag and run a container from your own image.

Environment: docker:24Launch Lab ⚡

TOPIC 03

Logs & Inspection

Containers are black boxes until you read their output.

What you'll practice

Capture Container Output — practice · beginner

A command you'll meet

docker run -d app:latest

Open any task below to get the full step-by-step walkthrough — every command is explained, and the lab validator checks what you actually built.

Hands-On Tasks in This Topic (1)

beginner

Practice Task

Capture Container Output

Run the app, capture its logs into a file with shell redirection and verify the port it listens on. Reading container output is the first step of debugging any container.

Environment: docker:24Launch Lab ⚡

TOPIC 04

Cleanup & Lifecycle

Stop, remove and keep the machine tidy.

What you'll practice

Clean Up Containers and Images — practice · beginner

A command you'll meet

docker ps

Open any task below to get the full step-by-step walkthrough — every command is explained, and the lab validator checks what you actually built.

Hands-On Tasks in This Topic (1)

beginner

Practice Task

Clean Up Containers and Images

Leftover containers and images eat disk on every real machine. Stop the running app, remove its container, then remove the image itself — and prove it's gone.

Environment: docker:24Launch Lab ⚡

TOPIC 05

Port Conflicts

What happens when two containers want the same host port, and how to remap safely.

What you'll practice

Untangle a Port Conflict — scenario · intermediate

A command you'll meet

docker run -d -p 8082:80 app:latest

Open any task below to get the full step-by-step walkthrough — every command is explained, and the lab validator checks what you actually built.

Hands-On Tasks in This Topic (1)

intermediate

Scenario

Untangle a Port Conflict

Staging needs its own copy of the app, but production already owns host port 8080 — and publishing a second container onto a busy host port fails with 'port is already allocated'. Prove who owns 8080, find a genuinely free port and give staging its own front door.

Environment: docker:24Launch Lab ⚡

TOPIC 06

Image Hardening

Smaller images, fewer privileges, fewer things for an attacker to hold on to.

What you'll practice

Run the Container as a Non-Root User — challenge · advanced
Build a Multi-Stage Image — challenge · advanced

A command you'll meet

docker build -t app:secure ~/app

Every line you leave out of an image is a line an attacker cannot use. Open the task below for the full walkthrough.

Hands-On Tasks in This Topic (2)

advanced

Challenge

Run the Container as a Non-Root User

Containers are often root on the host's behalf, which turns any bug into a host bug. Build an image that creates an unprivileged user and switches to it before the app starts.

Environment: docker:24Launch Lab ⚡

advanced

Challenge

Build a Multi-Stage Image

Build tools do not belong in a runtime image. Use two stages - one to compile, one to ship - so the final image only carries what the application needs to run.

Environment: docker:24Launch Lab ⚡