Why Docker Compose simplifies multi-container apps - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start all services defined in a Docker Compose file.

Docker

docker-compose [1]

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

Abuild

Brun

Cup

Dstop

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'build' instead of 'up' will only build images but not start containers.

Using 'stop' will stop running containers, not start them.

The docker-compose up command starts all the services defined in the docker-compose.yml file, making it easy to run multi-container apps with one command.

2fill in blank

medium

Complete the code to define a service named 'web' in a Docker Compose YAML file.

Docker

services:
  web:
    image: nginx
    ports:
      - "80:[1]"

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

A80

B8080

C443

D3000

Attempts:

3 left

💡 Hint

Common Mistakes

Using 8080 or 3000 as container port will not work with default nginx.

Using 443 is for HTTPS, not default HTTP.

Port mapping 80:80 means the host's port 80 maps to the container's port 80, which is the default HTTP port for nginx.

3fill in blank

hard

Fix the error in the Docker Compose command to rebuild images before starting containers.

Docker

docker-compose [1] --build

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

Arun

Bup

Cstart

Dbuild

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'start' ignores the --build flag.

Using 'build' only builds images but does not start containers.

The docker-compose up --build command rebuilds images before starting containers, which is useful after changing Dockerfiles.

4fill in blank

hard

Fill both blanks to define a volume named 'db-data' and mount it to '/var/lib/mysql' in the 'db' service.

Docker

services:
  db:
    image: mysql
    volumes:
      - [1]:[2]

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

Adb-data

B/var/lib/mysql

C/data

Dmysql-data

Attempts:

3 left

💡 Hint

Common Mistakes

Using '/data' instead of '/var/lib/mysql' will not persist MySQL data correctly.

Using 'mysql-data' instead of 'db-data' changes the volume name.

Volumes are named storage areas. Here, 'db-data' is the volume name, and '/var/lib/mysql' is the path inside the container where MySQL stores data.

5fill in blank

hard

Fill all three blanks to define a network named 'app-net', attach 'web' and 'db' services to it in Docker Compose.

Docker

networks:
  [1]:

services:
  web:
    image: nginx
    networks:
      - [2]

  db:
    image: mysql
    networks:
      - [3]

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

Aapp-net

Bdefault

Dbackend-net

Attempts:

3 left

💡 Hint

Common Mistakes

Using different network names breaks service communication.

Using 'default' network name when a custom network is defined.

Defining a network 'app-net' and attaching both 'web' and 'db' services to it allows them to communicate easily.