Why build optimization matters in Docker - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the Dockerfile command to set the base image.

Docker

FROM [1]

Drag options to blanks, or click blank then click option'

Aubuntu:20.04

BCOPY . /app

CRUN apt-get update

DEXPOSE 80

Attempts:

3 left

💡 Hint

Common Mistakes

Using commands like COPY or RUN instead of a base image after FROM.

The FROM command sets the base image for the Docker build. Here, ubuntu:20.04 is a valid base image.

2fill in blank

medium

Complete the Dockerfile command to copy files into the image.

Docker

COPY [1] /app

Drag options to blanks, or click blank then click option'

ARUN apt-get install -y curl

B.

C/app

DEXPOSE 8080

Attempts:

3 left

💡 Hint

Common Mistakes

Using commands like RUN or EXPOSE instead of a path.

The COPY command copies files from the current directory (represented by .) into the image's /app directory.

3fill in blank

hard

Fix the error in the Dockerfile command to run a package update.

Docker

RUN apt-get [1] update

Drag options to blanks, or click blank then click option'

Ainstall

Bupgrade

Cremove

Dupdate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'install' or 'upgrade' instead of 'update' in this context.

The correct command to update package lists is apt-get update. Using install or upgrade here is incorrect.

4fill in blank

hard

Fill both blanks to optimize the Dockerfile by combining commands.

Docker

RUN apt-get [1] && apt-get [2] -y curl

Drag options to blanks, or click blank then click option'

Aupdate

Binstall

Cremove

Dupgrade

Attempts:

3 left

💡 Hint

Common Mistakes

Reversing the order or using 'remove' or 'upgrade' incorrectly.

Combining apt-get update and apt-get install -y curl in one RUN command reduces image layers and speeds up builds.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that filters packages to install.

Docker

packages = {pkg: version for pkg, version in all_packages.items() if pkg [1] ['curl', [2], [3]]}

Drag options to blanks, or click blank then click option'

Ain

B'wget'

C'git'

Dnot in

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'not in' or forgetting quotes around package names.

This comprehension keeps only packages named 'curl', 'wget', or 'git' by checking if pkg is in the list.