Why understanding lifecycle matters in Docker - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the command to start a Docker container in detached mode.

Docker

docker run -d [1] nginx

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

A--rm

B-it

C-p 80:80

D-v /data:/data

Attempts:

3 left

💡 Hint

Common Mistakes

Using -it starts an interactive terminal, not detached mode.

Forgetting to map ports means the service won't be reachable.

The -p 80:80 option maps port 80 of the container to port 80 on the host, allowing web traffic. This is important when starting a web server container like nginx.

2fill in blank

medium

Complete the command to list all Docker containers, including stopped ones.

Docker

docker ps [1]

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

A-q

B--filter

C-l

D-a

Attempts:

3 left

💡 Hint

Common Mistakes

Using -q only shows container IDs.

Using -l shows only the last created container.

The -a option shows all containers, including those that are stopped. Without it, only running containers are listed.

3fill in blank

hard

Fix the error in the command to remove a stopped container named 'webapp'.

Docker

docker [1] webapp

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

Astop

Brm

Crun

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using stop only stops the container but does not remove it.

Using run tries to start a new container.

The rm command removes a container. You must stop it first if it is running. Here, the container is stopped, so docker rm webapp deletes it.

4fill in blank

hard

Fill both blanks to create a Dockerfile line that copies files and sets the working directory.

Docker

COPY [1] /app/
WORKDIR [2]

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

A.

B/app

C/usr/src/app

Dsrc

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong source path for COPY causes missing files.

Setting WORKDIR to a different folder than copied files causes confusion.

The COPY . /app/ copies all files from the current folder to /app in the container. Then WORKDIR /app sets the working directory inside the container to /app.

5fill in blank

hard

Fill all three blanks to write a Docker command that builds an image named 'myapp' from the current directory.

Docker

docker build [1] -t [2] [3]

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

A--no-cache

Bmyapp

C.

D-f Dockerfile

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the build context '.' causes errors.

Forgetting to tag the image results in an untagged image.

The -f Dockerfile option specifies the Dockerfile to use. The -t myapp tags the image with the name 'myapp'. The . tells Docker to use the current directory as the build context.