Registry mirroring concept in Docker - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the command to pull an image from a mirrored registry.

Docker

docker pull [1]/library/nginx:latest

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

Alocalhost

Bdocker.io

Cmirror.example.com

Dregistry.local

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'docker.io' pulls from the default registry, not the mirror.

Using 'localhost' assumes the mirror is local, which may not be true.

The mirror registry URL replaces the default Docker Hub URL to pull images from the mirror.

2fill in blank

medium

Complete the configuration file snippet to set up a registry mirror in Docker daemon.

Docker

{
  "registry-mirrors": ["[1]"]
}

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

Ahttp://registry.local

Bhttps://mirror.example.com

Chttps://docker.io

Dhttp://localhost:5000

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the protocol causes Docker to ignore the mirror.

Using the default registry URL does not set up mirroring.

The Docker daemon configuration requires the mirror URL with protocol to enable registry mirroring.

3fill in blank

hard

Fix the error in the command to start a local registry mirror container.

Docker

docker run -d -p 5000:5000 --name registry-mirror [1]

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Aregistry:2

Bregistry-mirror:latest

Cmirror-registry:1

Ddocker/registry

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent or incorrect image names causes container start failure.

Using unofficial images may not provide the registry functionality.

The official Docker registry image is 'registry:2'. Using this image starts a registry container suitable for mirroring.

4fill in blank

hard

Fill both blanks to configure Docker daemon to use a mirror and disable the default registry.

Docker

{
  "registry-mirrors": ["[1]"],
  "insecure-registries": ["[2]"]
}

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

Ahttps://mirror.example.com

Bmirror.example.com

Cdocker.io

Dlocalhost:5000

Attempts:

3 left

💡 Hint

Common Mistakes

Using the same format for both settings causes configuration errors.

Omitting the port in 'insecure-registries' when needed causes connection failures.

The 'registry-mirrors' setting requires the full URL with protocol, while 'insecure-registries' uses the host and port without protocol.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that filters images from the mirror with size greater than 100MB.

Docker

filtered_images = {img: size [1] size for img, size in images.items() if size [2] [3]

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

A*

B>

C100 * 1024 * 1024

D**

Attempts:

3 left

💡 Hint

Common Mistakes

Using '**' instead of '*' causes exponentiation, not multiplication.

Using '<' instead of '>' changes the filter logic.

Using raw 100 instead of bytes causes incorrect filtering.

The comprehension multiplies size by itself (size * size) and filters sizes greater than 100MB (100 * 1024 * 1024 bytes).