Docker - Images - multichoice questions

Question 1

How many layers is the image sonatype/nexus3:3.41.0 composed by?

Question 2

Given the bellow directory structure for a Go app:

.
|-- app.Dockerfile
|-- cmd
|   |-- client
|   |   |-- main.go
|   |   |-- request.go
|   |   |-- ui.go
|   |-- server
|       |-- main.go
|       |-- translate.go
|-- go.mod
|-- go.sum

The app should be built with a Dockerfile named app.Dockerfile (instead the default name of Dockerfile). Which command can build the app?

docker build -t myapp .
docker build -t myapp -f app.Dockerfile .
docker build -f app.Dockerfile .
docker build -t myapp -f app.Dockerfile ./server

Question 3

Given a linux machine with OS architecture of arm/v5. What happens when running the following command:

docker run nginx:1.24.0

The command fails since this architecture is not supported by the nginx:1.24.0 image.
The running succeed since this architecture is supported by the nginx:1.24.0 image and docker automatically selects the image that matches your OS and architecture.
The running fails. Although this architecture is supported by the nginx:1.24.0 image, you should tell docker this type of OS and architecture.
The running succeed since your OS architecture is not matter. The container can be run everywhere.

Question 4

In the terminal, you are current working directory is /home/user/app and you want to build a Docker image for your application located in /home/user/app/src directory. The Dockerfile is also located in /home/user/app/src.

Which of the following command(s) will build the app?

docker build -t myapp .
docker build -t myapp ../
docker build -t myapp src/
docker build -t myapp /home/user/app/src

Question 5

What is wrong in the bellow Dockerfile:

FROM python:3.10.15
WORKDIR /test
COPY ../tutorials .
RUN pip install -r requirements.txt

CMD ["python3", "app.py"]

The workdir should be /app.
The base image python:3.10.15 doesn't exist.
Docker doesn't allow copying files from outside the build context (../)
The CMD should be CMD "python app.py".

Question 6

What happens when you run a Docker image that was packed with a Linux kernel different from the kernel of the host machine (the machine the container is running on)?

System calls will fail frequently.
The docker daemon will not let you run the image.
Images don't contain a kernel — all containers running on a host machine share access to the host's kernel.
The image will run smoothly as the docker daemon deals with kernels compatibility.

Question 7

You are told that the python docker image consists of 8 layers. You build a new image according to the following dockerfile:

FROM python
WORKDIR /test

How many layers your image will consist by?

8 layer since WORKDIR /test doesn't add new layer.
9 layer since WORKDIR /test adds 1 new layer.
10 layer since WORKDIR /test adds new 2 layers.
You can't know the number of layers.

Question 8

In a Dockerfile, suppose you have the following line: COPY app/ /usr/src/app/. Assume the owner and group of app directory on your host machine is elvis, which its UID (user id) is 1000 and GID (group id) is 1000.

What will be the UID and GID of the files in the /usr/src/app directory in the resulting Docker image?

0.
1000.
Files in an imag"e doesn't have UID and GID.
None of the above.

Question 9

Your Flask app is expecting an environment variable called FLASK_APP. How can you define this variable in the build time, within your Dockerfile?

By the instruction ENV FLASK_APP=app.py.
By the instruction ENV FLASK_APP app.py.
By the instruction ARG FLASK_APP=app.py.
By the instruction RUN FLASK_APP=app.py.

Question 10

Given an image called curl-tool built using the below Dockerfile

FROM ubuntu
LABEL description="Containerized `curl` tool image"

RUN apt update && apt install curl -y

ENTRYPOINT ["curl"]
CMD ["google.com"]

Which of the following docker run commands will be running successfully?

docker run curl-tool
docker run curl-tool github.com
docker run -it curl-tool /bin/bash
docker run curl-tool ls