XK0-005 Scripting, Containers, and Automation — Timed 25 Questions

Question 1

A Linux administrator wants to ensure a bash script stops execution immediately if any command fails. Which line should be added to the script?

Accepted Answer

set -e. The 'set -e' command causes the script to exit immediately when a command returns a non-zero exit status.

Answer

set -x

Answer

set -u

Answer

set -o pipefail

Question 2

A developer is writing a Dockerfile. The application requires a configuration file that should be copied from the build context and the container should expose port 8080. Which combination of Dockerfile instructions is correct?

Accepted Answer

COPY config.txt /app/ and EXPOSE 8080. COPY adds files from the build context, and EXPOSE documents the port. Other instructions serve different purposes.

Answer

ADD config.txt /app/ and WORKDIR 8080

Answer

ADD config.txt /app/ and RUN expose 8080

Answer

COPY config.txt /app/ and CMD 8080

Question 3

An administrator is writing a bash script that loops through all .log files in /var/log and prints the file name if the file is larger than 100 kilobytes. Which loop correctly implements this?

Accepted Answer

find /var/log -name '*.log' -size +100k -exec echo {} \;. The find command with -size filters files larger than 100k, and -exec with {} runs the command for each file. The other options have syntax errors or incorrect logic.

Answer

ls -l /var/log/*.log | awk '$5>100 {print $NF}'

Answer

for f in /var/log/*.log; do if [ -s $f -a $(stat -c%s $f) -gt 100 ]; then echo $f; fi; done

Answer

for f in /var/log/*.log; do if [ $f -gt 100k ]; then echo $f; fi; done

Question 4

A team uses Ansible for configuration management. They want to ensure a service is running on all managed nodes. Which Ansible module should be used in the playbook?

Accepted Answer

service. The service module manages services (start, stop, restart, etc.). The other modules are for different purposes.

Answer

systemd

Answer

command

Answer

shell

Question 5

A Docker container is running in the background. Which command allows the administrator to execute an interactive bash shell inside the running container named 'webapp'?

Accepted Answer

docker exec -it webapp bash. docker exec -it runs an interactive command in a running container. The other commands are for different purposes.

Answer

docker start -i webapp

Answer

docker run -it webapp bash

Answer

docker attach webapp

Question 6

In a bash script, a developer needs to parse command-line options such as -f filename and -v (verbose). Which built-in command is best suited for this task?

Accepted Answer

getopts. getopts is a bash built-in for parsing command-line options. It handles short options and requires option arguments.

Answer

getopt

Answer

case

Answer

shift

Question 7

An administrator is troubleshooting a Kubernetes deployment that is not receiving traffic. The deployment has one replica and the pod is running. The service is of type ClusterIP. Which command would help verify that the service endpoints are correctly associated with the pod?

Accepted Answer

kubectl get endpoints. kubectl describe service shows the endpoints and selector labels. The other commands show different information.

Answer

kubectl describe pod

Answer

kubectl get pods -o wide

Answer

kubectl get svc

Question 8

A DevOps engineer wants to run a Docker container with a bind mount to make a host directory /data available at /mnt/data inside the container. Which command is correct?

Accepted Answer

docker run --mount type=bind,source=/data,target=/mnt/data ubuntu. Option C is correct because the `--mount` flag with `type=bind` explicitly creates a bind mount, mapping the host directory `/data` to the container path `/mnt/data`. This syntax is more explicit and less error-prone than the older `-v` flag, especially when dealing with bind mounts on directories that do not exist yet or when additional mount options are needed.

Answer

docker run -v /data:/mnt/data:bind ubuntu

Answer

docker run -v /data:/mnt/data ubuntu

Answer

docker run --mount type=volume,source=/data,target=/mnt/data ubuntu

Question 9

In bash, what is the difference between single quotes and double quotes?

Accepted Answer

Single quotes prevent variable expansion, double quotes allow it.. Single quotes preserve the literal value of each character, while double quotes allow variable expansion and command substitution.

Answer

Both allow variable expansion, but double quotes also allow globbing.

Answer

Single quotes allow variable expansion, double quotes do not.

Answer

There is no difference; they are interchangeable.

Question 10

An administrator needs to create a Docker image from a Dockerfile located in the current directory and tag it as 'myapp:v1'. Which command should be used?

Accepted Answer

docker build -t myapp:v1 .. docker build with -t tag creates the image. The period indicates the build context.

Answer

docker create -t myapp:v1 .

Answer

docker commit myapp:v1 .

Answer

docker image create myapp:v1 .

Question 11

In a bash script, a variable is set as follows: myvar='Hello World'. Which of the following correctly prints the first 5 characters of the variable?

Accepted Answer

echo ${myvar:0:5}. Parameter expansion ${myvar:0:5} extracts a substring starting at position 0 of length 5. The other options are incorrect syntax.

Answer

echo ${myvar#?????}

Answer

echo ${myvar:0-5}

Answer

echo ${myvar:5}

Question 12

A Podman user wants to run a container that automatically removes itself after it stops, runs in detached mode, and maps host port 80 to container port 8080. Which command is correct?

Accepted Answer

podman run --rm -d -p 80:8080 nginx. The correct command is `podman run --rm -d -p 80:8080 nginx`. Option A incorrectly maps port 8080 on the host to port 80 in the container (should be host:container). Option C uses an invalid flag `--remove`; the correct flag is `--rm`. Options B and D are identical commands, both using the correct flags. Therefore, if B is correct, D should also be correct; the discrepancy is likely a typo in the question.

Answer

podman run -rm -d -p 8080:80 nginx

Answer

podman run --remove -d -p 80:8080 nginx

Answer

podman run --rm -d -p 80:8080 nginx

Question 13

A system administrator is writing a bash script that must check if a file exists and is readable before processing. Which TWO test expressions can be used in an if statement? (Select TWO.)

Accepted Answer

[ -e /path/to/file ]. The -e test checks existence, and -r checks readability. Other options are for different attributes.

Answer

[ -f /path/to/file ]

Answer

[ -x /path/to/file ]

Answer

[ -s /path/to/file ]

Question 14

A Kubernetes administrator is creating a deployment YAML manifest. Which THREE fields are required in a Deployment spec? (Select THREE.)

Accepted Answer

apiVersion. A Deployment requires apiVersion, kind, and metadata. The other fields are part of the spec but not top-level required fields.

Answer

replicas

Answer

spec

Question 15

An Ansible playbook is being written to manage web servers. Which TWO modules can be used to ensure a package is installed? (Select TWO.)

Accepted Answer

apt. The apt module is for Debian-based systems, and yum is for Red Hat-based systems. Both manage packages.

Answer

copy

Answer

service

Answer

template

Question 16

A Linux administrator writes a Bash script and includes the line `#!/bin/bash` at the top. What is the purpose of this line?

Accepted Answer

It specifies the interpreter to execute the script.. The shebang line tells the system which interpreter to use to execute the script. In this case, it specifies the Bash shell.

Answer

It sets the script to run in the background.

Answer

It enables debugging mode.

Answer

It defines a variable for the script.

Question 17

A developer is writing a Bash script that needs to test whether a file exists and is readable. Which of the following conditionals correctly performs this check?

Accepted Answer

if [[ -f $file && -r $file ]]; then. The -f test checks for a regular file, and -r checks if it is readable. Both must be true, so they are combined with &&.

Answer

if test -f $file || test -r $file; then

Answer

if [ -f $file -a -r $file ]; then

Answer

if [ -f $file -o -r $file ]; then

Question 18

A Linux administrator is troubleshooting a Bash script that unexpectedly terminates when a command fails. The script uses `#!/bin/bash`. Which of the following commands, if placed at the beginning of the script, would cause it to exit on any command failure?

Accepted Answer

set -e. The `set -e` option makes the shell exit immediately if a command exits with a non-zero status.

Answer

set -u

Answer

trap 'exit 1' ERR

Answer

set -o pipefail

Question 19

A user wants to run a Docker container in detached mode, remove it automatically after it stops, and map host port 8080 to container port 80. Which command accomplishes this?

Accepted Answer

docker run -d --rm -p 8080:80 image. docker run --rm -d -p 8080:80 image runs in detached mode (-d), auto-removes (--rm), and maps port 8080 to 80.

Answer

docker run -it --rm -p 80:8080 image

Answer

docker create --rm -p 8080:80 image

Answer

docker start -d -p 8080:80 image

Question 20

A DevOps engineer is writing a Dockerfile. The application requires environment variables to be set at runtime from a file. Which Dockerfile instruction should be used to achieve this?

Accepted Answer

ENV. The ENV instruction sets environment variables in the Dockerfile, but for runtime from a file, the --env-file option is used with docker run. However, within the Dockerfile, ENV is the instruction to set environment variables.

Answer

CMD export

Answer

ARG

Answer

RUN export