Defining services in Docker - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a service named 'web' using the nginx image.

Docker

services:
  web:
    image: [1]

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

Anginx

Bmysql

Credis

Dubuntu

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a database image like mysql instead of a web server image.

Using an OS image like ubuntu which doesn't run a web server by default.

The image field specifies which Docker image the service uses. Here, 'nginx' is the correct image for a web server.

2fill in blank

medium

Complete the code to expose port 80 on the 'web' service.

Docker

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

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

A8080

B443

C80

D3306

Attempts:

3 left

💡 Hint

Common Mistakes

Using port 8080 on the host without knowing if it is intended.

Using port 443 which is for HTTPS, not HTTP.

The ports mapping format is host_port:container_port. To expose port 80 on the host to port 80 in the container, use '80:80'.

3fill in blank

hard

Fix the error in the service definition by completing the restart policy.

Docker

services:
  web:
    image: nginx
    restart: [1]

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

Aalways

Bnever

Csometimes

Don-failure

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'sometimes' which is not a valid restart policy.

Using 'never' which disables restart.

The restart policy 'always' ensures the container restarts automatically if it stops.

4fill in blank

hard

Fill both blanks to define environment variables for the 'db' service.

Docker

services:
  db:
    image: mysql
    environment:
      - [1]=root
      - [2]=password123

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

AMYSQL_USER

BMYSQL_ROOT_PASSWORD

CMYSQL_PASSWORD

DMYSQL_DATABASE

Attempts:

3 left

💡 Hint

Common Mistakes

Using MYSQL_ROOT_PASSWORD for a non-root user password.

Confusing MYSQL_DATABASE with user credentials.

Environment variables for MySQL include MYSQL_USER for the username and MYSQL_PASSWORD for the user's password.

5fill in blank

hard

Fill all three blanks to define a volume mount for the 'web' service.

Docker

services:
  web:
    image: nginx
    volumes:
      - [1]:[2]:[3]

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

A./html

B/usr/share/nginx/html

Cro

Drw

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'rw' instead of 'ro' when read-only is intended.

Swapping host and container paths.

The volume mount syntax is host_path:container_path:mode. Here, ./html is the folder on the host, /usr/share/nginx/html is the container folder, and ro means read-only.