CMD instruction for default command in Docker - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the Dockerfile to set the default command to run nginx.

Docker

CMD ["[1]"]

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

Abash

Bnode

Cnginx

Dpython

Attempts:

3 left

💡 Hint

Common Mistakes

Using shell form without brackets

Choosing a command not installed in the image

The CMD instruction sets the default command to run when the container starts. Here, nginx is the default command.

2fill in blank

medium

Complete the Dockerfile to set the default command to run python app.py using exec form.

Docker

CMD ["python", "[1]"]

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

Aapp.py

Brun.py

Cmain.py

Dserver.py

Attempts:

3 left

💡 Hint

Common Mistakes

Using shell form instead of exec form

Misspelling the Python file name

The CMD uses exec form with python as the command and app.py as the argument to run the application.

3fill in blank

hard

Fix the error in this Dockerfile line to correctly set the default command to bash.

Docker

CMD [1]

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

A[bash]

Bbash

C"bash"

D["bash"]

Attempts:

3 left

💡 Hint

Common Mistakes

Using shell form without brackets

Missing quotes around the command

The CMD instruction in exec form requires the command and arguments inside brackets and quotes, like ["bash"].

4fill in blank

hard

Fill both blanks to set the default command to run node server.js in exec form.

Docker

CMD ["[1]", "[2]"]

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

Anode

Bserver.js

Capp.js

Dnpm

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the command and file name

Using npm instead of node

The CMD instruction uses exec form with node as the command and server.js as the argument.

5fill in blank

hard

Fill all four blanks to set the default command to run python3 -m http.server 8000 in exec form.

Docker

CMD ["[1]", "[2]", "[3]", "[4]"]

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

Apython3

B-m

Chttp.server

D8000

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the http.server module argument

Using python instead of python3

The CMD instruction in exec form requires each part as a separate argument: ["python3", "-m", "http.server", "8000"].