Which of the following commands would allow this to happen?

A Linux administrator is providing a new Nginx image from the registry to local cache.

Which of the following commands would allow this to happen?
A . docker pull nginx
B . docker attach nginx
C . docker commit nginx
D . docker import nginx

View Answer

Answer: A

Explanation:

The command that would allow this to happen is docker pull nginx. Docker is a software platform that allows the administrator to create, run, and manage containers on Linux systems. Containers are isolated and lightweight environments that can run applications and services without affecting the host system. Docker uses images to create containers, which are files that contain the code, libraries, dependencies, and configuration of the applications and services. Docker uses a registry to store and distribute images, which is a service that hosts and serves images. Docker Hub is the default public registry that provides a large number of official and community images. Nginx is a popular web server and reverse proxy that can run as a container. The command docker pull nginx will download the latest version of the Nginx image from the Docker Hub registry to the local cache, which is the storage location for the images on the host system. This will allow the administrator to provide a new Nginx image from the registry to the local cache. This is the correct command to use to accomplish the task. The other options are incorrect because they either do not download an image from the registry (docker attach nginx or docker commit nginx) or do not exist (docker import nginx).

References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 19: Managing Cloud and Virtualization Technologies, page 571.