Exposing ports to host in Docker - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the command to expose port 80 of the container to port 8080 on the host.

Docker

docker run -p [1]:80 nginx

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

A3000

B8080

C443

D80

Attempts:

3 left

💡 Hint

Common Mistakes

Using the container port as the host port.

Swapping the ports in the mapping.

The -p option maps a host port to a container port. Here, port 8080 on the host is mapped to port 80 inside the container.

2fill in blank

medium

Complete the command to expose port 5432 of the container to the same port on the host.

Docker

docker run -p [1]:5432 postgres

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

A3306

B8080

C5432

D5000

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different host port without reason.

Confusing container port with host port.

Mapping port 5432 on the host to port 5432 in the container allows direct access to the database service.

3fill in blank

hard

Fix the error in the command to expose port 5000 of the container to port 5000 on the host.

Docker

docker run -p 5000:[1] myapp

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

A5000

B443

C80

D8080

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping host and container ports.

Using a default port not matching the app.

The container port must match the port your app listens on, here 5000.

4fill in blank

hard

Fill both blanks to expose port 3000 of the container to port 4000 on the host and run the container in detached mode.

Docker

docker run [1] -p [2]:3000 myapp

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

A-d

B-it

C4000

D-rm

Attempts:

3 left

💡 Hint

Common Mistakes

Using interactive mode instead of detached.

Swapping host and container ports.

-d runs the container detached (in background). The port mapping 4000:3000 exposes container port 3000 on host port 4000.

5fill in blank

hard

Fill all three blanks to expose port 22 of the container to port 2222 on the host, name the container 'ssh-server', and run it in detached mode.

Docker

docker run [1] --name [2] -p [3]:22 sshd

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

A-d

Bssh-server

C2222

D-it

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to name the container.

Using wrong port mapping order.

Using interactive mode instead of detached.

-d runs the container detached, --name ssh-server names the container, and -p 2222:22 maps host port 2222 to container port 22.