EXPOSE instruction for ports in Docker - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the Dockerfile line to expose port 80.

Docker

EXPOSE [1]

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

A22

B443

C80

D8080

Attempts:

3 left

💡 Hint

Common Mistakes

Using port 22 which is for SSH, not HTTP.

Confusing port 443 which is for HTTPS.

The EXPOSE instruction tells Docker which port the container listens on at runtime. Port 80 is the default HTTP port.

2fill in blank

medium

Complete the Dockerfile line to expose port 5432 for a PostgreSQL database.

Docker

EXPOSE [1]

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

A5432

B3306

C6379

D27017

Attempts:

3 left

💡 Hint

Common Mistakes

Using port 3306 which is for MySQL.

Using port 6379 which is for Redis.

Port 5432 is the default port for PostgreSQL database connections.

3fill in blank

hard

Fix the error in the Dockerfile line to expose port 5000 (remove the wrong character).

Docker

EXPOSE [1]

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

A5000/

B5000

C5000/tcp

Dtcp/5000

Attempts:

3 left

💡 Hint

Common Mistakes

Adding a slash after the port number.

Including protocol in the wrong format.

The EXPOSE instruction should have only the port number without extra characters. '5000/' is invalid syntax.

4fill in blank

hard

Fill both blanks to expose HTTP and HTTPS ports in the Dockerfile.

Docker

EXPOSE [1] [2]

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

A80

B22

C443

D8080

Attempts:

3 left

💡 Hint

Common Mistakes

Using port 22 which is for SSH.

Confusing port 8080 with standard HTTP port.

Port 80 is for HTTP and port 443 is for HTTPS. Both are commonly exposed for web servers.

5fill in blank

hard

Fill all three blanks to expose ports for HTTP, PostgreSQL, and Redis.

Docker

EXPOSE [1] [2] [3]

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

A80

B5432

C6379

D22

Attempts:

3 left

💡 Hint

Common Mistakes

Including port 22 which is for SSH and not relevant here.

Mixing up database ports.

Port 80 is for HTTP, 5432 for PostgreSQL, and 6379 for Redis. These are standard ports to expose for these services.