Which of the following commands should the administrator run to ensure both versions are available?

A Linux administrator needs to ensure that Java 7 and Java 8 are both locally available for developers to use when deploying containers. Currently only Java 8 is available.

Which of the following commands should the administrator run to ensure both versions are available?
A . docker image load java:7
B . docker image pull java:7
C . docker image import java:7
D . docker image build java:7

View Answer

Answer: B

Explanation:

The command that the administrator should run to ensure that both Java 7 and Java 8 are locally available for developers to use when deploying containers is docker image pull java:7. This command will use the docker image pull subcommand to download the java:7 image from Docker Hub, which is the default registry for Docker images. The java:7 image contains Java 7 installed on a Debian-based Linux system. The administrator can also specify a different registry by using the syntax registry/repository:tag.

The other options are not correct commands for ensuring that both Java 7 and Java 8 are locally available for developers to use when deploying containers. The docker image load java:7 command will load an image from a tar archive or STDIN, not from a registry. The docker image import java:7 command will create a new filesystem image from the contents of a tarball, not from a registry. The docker image build java:7 command will build an image from a Dockerfile, not from a registry.

Reference: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 18: Automating Tasks; docker image pull | Docker Docs