Why Dockerfiles automate image creation - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the Dockerfile command to specify the base image.

Docker

FROM [1]

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

Aubuntu:latest

BRUN apt-get update

CCOPY . /app

DCMD ["bash"]

Attempts:

3 left

💡 Hint

Common Mistakes

Using RUN or COPY instead of FROM to specify the base image.

The FROM command sets the base image for the Docker image. Here, ubuntu:latest is a common base.

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'

ACMD ["python"]

BRUN apt-get install

C/app

D.

Attempts:

3 left

💡 Hint

Common Mistakes

Using commands like RUN or CMD instead of a path for COPY.

The COPY command copies files from the current directory . into the image's /app folder.

3fill in blank

hard

Fix the error in the Dockerfile command to run a shell command.

Docker

[1] apt-get update

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

ARUN

BCMD

CCOPY

Dapt-get

Attempts:

3 left

💡 Hint

Common Mistakes

Using COPY or CMD instead of RUN for shell commands.

The RUN command executes shell commands during image build. Here, it runs apt-get update.

4fill in blank

hard

Fill both blanks to set the working directory and default command.

Docker

WORKDIR [1]
CMD [2]

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

A/app

B["python", "app.py"]

C["bash"]

D/usr/src

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up WORKDIR and CMD values.

WORKDIR sets the folder where commands run. CMD sets the default command to run when the container starts.

5fill in blank

hard

Fill all three blanks to create a dictionary of environment variables in a Dockerfile.

Docker

ENV [1]=[2] [3]

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

AAPP_ENV

Bproduction

CDEBUG=false

DPATH

Attempts:

3 left

💡 Hint

Common Mistakes

Using invalid syntax or missing equal signs in ENV.

The ENV command sets environment variables inside the image. Here, APP_ENV=production and DEBUG=false are set.