A systems administrator wants to upgrade /bin/ someapp to a new version, but the administrator does not know the package name. Which of the following will
show the RPM package name that provides that binary file?
Correct Answer:
A
The rpm command is used to manage RPM packages on Linux systems. The -qf option queries the package name that provides a given file. Therefore, the command rpm -qf /bin/someapp will show the RPM package name that provides the binary file /bin/someapp. The statements B, C, and D are incorrect because they do not query the package name, but rather verify, remove, or install a package. References: [How to Use RPM Command in Linux with Examples]
A cloud engineer needs to remove all dangling images and delete all the images that do not have an associated container. Which of the following commands will help to accomplish this task?
Correct Answer:
A
The command docker images prune -a will help to remove all dangling images and delete all the images that do not have an associated container.
The docker command is a tool for managing Docker containers and images.
The images subcommand operates on images. The prune option removes unused images.
The -a option removes all images, not just dangling ones. A dangling image is an image that is not tagged and is not referenced by any container. This command will accomplish the task of cleaning up the unused images. The other options are incorrect because they either do not exist (docker push images -a or docker images rmi --all) or do not remove images (docker rmi -a images only removes images that match the name or ID of “images”). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 19: Managing Cloud and Virtualization Technologies, page 567.
A systems administrator created a web server for the company and is required to add a tag for the API so end users can connect. Which of the following would the administrator do to complete this requirement?
Correct Answer:
C
The command hostnamectl set-hostname Comptia-WebNode -H root@192.168.2.14 sets the hostname of the web server to Comptia-WebNode and connects to the server using the SSH protocol and the root user. This is the correct way to complete the requirement. The other options are incorrect because they either display the current hostname status (hostnamectl status), set an invalid hostname (hostnamectl set- hostname "$(perl -le "print" "A" x 86)"), or set a transient hostname that is not persistent (hostnamectl set-hostname Comptia-WebNode --transient). References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 9: Managing System Components, page 291.
A Linux administrator has been tasked with installing the most recent versions of packages on a RPM-based OS. Which of the following commands will accomplish this task?
Correct Answer:
D
The dnf update command will accomplish the task of installing the most recent versions of packages on a RPM-based OS. This command will check for available updates from the enabled repositories and apply them to the system. The apt-get upgrade command is used to install updates on a Debian-based OS, not a RPM-based OS. The rpm -a command is invalid, as -a is not a valid option for rpm. The yum updateinfo command will display information about available updates, but it will not install them. The yum check- update command will check for available updates, but it will not install them. References: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 19: Managing Packages and Software, page 559.
A systems administrator is configuring a Linux system so the network traffic from the internal network 172.17.0.0/16 going out through the eth0 interface would appear as if it was sent directly from this interface. Which of the following commands will accomplish this task?
Correct Answer:
A
This command will use the iptables tool to append a rule to the POSTROUTING chain of the nat table, which will match any packet with a source address of 172.17.0.0/16 and an output interface of eth0, and apply the MASQUERADE target to it. This means that the packet will have its source address changed to the address of the eth0 interface, effectively hiding the internal network behind a NAT12.
References: 1: Iptables NAT and Masquerade rules - what do they do? 2: Routing from docker containers using a different physical network interface and default gateway
