XK0-005 Scripting, Containers and Automation Practice Test 6 — 15 Questions

Question 1

A system administrator wants to deploy a containerized application on a Linux server with minimal overhead and without a daemon. Which container runtime should be used?

Accepted Answer

Podman. Podman is the correct choice because it is a daemonless container engine that runs containers directly under the user's process space, using a fork-exec model rather than a background daemon. This aligns with the requirement for minimal overhead and no daemon, as Podman does not require a persistent service to manage containers.

Answer

containerd

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LXC

Answer

Docker

Question 2

A DevOps team uses Git for version control of Ansible playbooks. They notice that a recent commit introduced errors in the playbook. Which Git command sequence should they use to temporarily revert to a previous commit while preserving the faulty commit in history?

Accepted Answer

git revert HEAD. The `git revert HEAD` command creates a new commit that undoes the changes introduced by the most recent commit, effectively reverting the playbook to its previous state while preserving the faulty commit in the project history. This is the correct approach for a team using shared repositories because it maintains a linear, non-destructive history that can be safely pushed to a remote without force-pushing.

Answer

git checkout HEAD~1

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git reset --hard HEAD~1

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git branch -d faulty-branch

Question 3

A junior administrator is writing a bash script that should exit immediately if any command in a pipeline fails. Which command should be added at the beginning of the script?

Accepted Answer

set -o pipefail. Option D is correct because `set -o pipefail` ensures that if any command in a pipeline fails (returns a non-zero exit status), the entire pipeline is considered to have failed, and with `set -e` (which is often used alongside it), the script will exit immediately. This is specifically required by the question: 'exit immediately if any command in a pipeline fails.' Without `pipefail`, only the exit status of the last command in the pipeline is considered, so earlier failures would be ignored.

Answer

set -u

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shopt -s extglob

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set -e

Question 4

An administrator needs to run a container using a specific user ID to match host file permissions. Which Docker option should be used when running the container?

Accepted Answer

-u 1001. The `-u` (or `--user`) option in Docker allows you to run the container process with a specific user ID (UID) instead of the default root (UID 0). By specifying `-u 1001`, the container's main process will run as UID 1001, which can be matched to a host user's UID to ensure proper file ownership and permissions when accessing mounted volumes. This is essential for avoiding permission denied errors when the container writes files to a bind-mounted host directory.

Answer

-e USER=1001

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-v /host:/container

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--name mycontainer

Question 5

Which THREE of the following are valid ways to define environment variables in a Docker container? (Choose three.)

Accepted Answer

Passing with docker run -e VAR=value. Option A is correct because the `docker run -e VAR=value` syntax directly sets an environment variable inside the container at runtime. This overrides any ENV instruction in the Dockerfile for that specific run, giving the operator flexibility without modifying the image.

Answer

Using the ARG instruction in Dockerfile

Question 6

A Linux engineer needs to ensure a bash script runs with strict error handling. Which TWO of the following should be included? (Choose two.)

Accepted Answer

set -o pipefail. Option A, 'set -o pipefail', is correct because it ensures that if any command in a pipeline fails (returns a non-zero exit status), the entire pipeline's exit status reflects that failure. Without it, only the last command's exit status is considered, which can mask errors in earlier pipeline stages. Option C, 'set -e', is correct because it causes the script to exit immediately upon any command returning a non-zero exit status, preventing silent failures from propagating.

Answer

set -n

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set -x

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shopt -s histappend

Question 7

Which TWO of the following are characteristics of containers compared to virtual machines? (Choose two.)

Accepted Answer

Containers require less overhead than VMs.. Option D is correct because containers share the host OS kernel and do not require a full guest OS per instance, resulting in significantly lower resource overhead (CPU, memory, and storage) compared to virtual machines. Option E is correct because containers are lightweight processes that can start in seconds, whereas VMs require booting an entire operating system, which typically takes minutes.

Answer

Containers run their own kernel.

Answer

Each container has its own operating system.

Answer

Containers use hypervisor for isolation.

Question 8

A junior administrator writes a bash script to check disk usage and send an email alert. The script runs manually but does not execute from cron. Which of the following is the most likely cause?

Accepted Answer

Absolute path not specified in crontab. When a script runs manually from the command line but fails from cron, the most common cause is that cron does not inherit the user's PATH environment. Without an absolute path to the script in the crontab entry, cron cannot locate the script. Option D directly addresses this: specifying the full path (e.g., /home/user/script.sh) ensures cron can find and execute it.

Answer

Script not marked executable

Answer

Incorrect file permissions on cron job

Answer

Missing shebang line

Question 9

A script uses 'set -e' and then calls a function that returns a non-zero exit status. The script exits unexpectedly. Which of the following should be added to the function to prevent the script from exiting?

Accepted Answer

set +e inside the function. The `set -e` directive causes the shell to exit immediately if any command returns a non-zero exit status. When a function called from such a script returns a non-zero status, the script exits. Adding `set +e` inside the function disables this behavior for the function's scope, allowing the function to handle errors internally without terminating the entire script.

Answer

return 0 after the command

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exit 0

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trap '' ERR

Question 10

A DevOps engineer is creating a Podman container that needs to communicate with a host service listening on a Unix socket at /run/host-service.sock. Which of the following mount options will make the socket available inside the container?

Accepted Answer

--volume /run/host-service.sock:/run/host-service.sock. Option C is correct because `--volume` in Podman (and Docker) can bind-mount a single file, such as a Unix socket, from the host into the container. This makes `/run/host-service.sock` available at the same path inside the container, allowing the containerized process to communicate with the host service over the socket.

Answer

--device /run/host-service.sock:/run/host-service.sock

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--bind /run/host-service.sock:/run/host-service.sock

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--mount type=bind,source=/run/host-service.sock,target=/run/host-service.sock

Question 11

An administrator wants to ensure that a web service starts after the database service has fully initialized. Which TWO methods can be used to achieve this ordering dependency in systemd?

Accepted Answer

Add Requires=db.service in the [Unit] section. Option A is correct because `Requires=db.service` in the `[Unit]` section declares a strong dependency: if `db.service` fails to start, `web.service` will not be started. Option B is correct because `After=db.service` in the `[Unit]` section of `web.service` ensures that `web.service` starts only after `db.service` has reached the 'active' state, enforcing the required ordering. Together, these two directives guarantee both dependency and sequencing.

Answer

Add BindsTo=db.service in the [Unit] section

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Add Wants=db.service in the [Unit] section

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Add PartOf=db.service in the [Unit] section

Question 12

A team uses Ansible for configuration management. A playbook fails with the error 'ERROR! Syntax Error while loading YAML script'. Which of the following is the most likely cause?

Accepted Answer

Incorrect indentation in the YAML file. The error 'Syntax Error while loading YAML script' indicates that Ansible's YAML parser encountered a structural problem in the playbook file. The most common cause in YAML is incorrect indentation, because YAML relies on consistent spacing (typically 2 spaces per level) to define the hierarchy of tasks, plays, and variables. A missing SSH key would produce a connection or authentication error, not a YAML syntax error.

Answer

Missing SSH key

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Invalid module name

Answer

Playbook not executable

Question 13

A storage administrator needs to automate the expansion of an LVM volume group when free space drops below 10%. The script must add a new physical volume from a spare disk. Which of the following commands should be used in the script to add the new disk to the volume group?

Accepted Answer

pvcreate /dev/sdb1 && vgextend vg01 /dev/sdb1. Option A is correct because it first uses `pvcreate` to initialize the spare disk partition `/dev/sdb1` as a physical volume, which is a prerequisite for adding it to an LVM volume group. Then `vgextend vg01 /dev/sdb1` adds that initialized physical volume to the existing volume group `vg01`, expanding its total capacity. This two-step process ensures the disk is properly prepared for LVM management before being incorporated into the volume group.

Answer

vgcreate vg01 /dev/sdb

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vgextend vg01 /dev/sdb1

Answer

lvresize -L +100G vg01

Question 14

A script receives a JSON object where keys are user IDs. Which command extracts the 'status' of user id '123'?

Accepted Answer

echo "$json" | jq '.["123"].status'. Option D is correct because the JSON object uses user IDs as keys, so `.["123"]` directly accesses the object property for user ID '123', and `.status` extracts the 'status' field from that nested object. The `jq` syntax `.["key"]` is the standard way to access a property by a string key in a JSON object.

Answer

echo "$json" | jq '.status'

Answer

echo "$json" | jq '. | select(.id=="123") | .status'

Answer

echo "$json" | jq '.[] | select(.id=="123") | .status'

Question 15

A security-conscious administrator runs containers with Podman. Which THREE methods ensure that a container runs with the least privilege required?

Accepted Answer

--user 1000. Option B is correct because using `--user 1000` runs the container process with a non-root user (UID 1000), which reduces the attack surface by preventing root-level access inside the container. This is a fundamental least-privilege practice, as containers default to running as root unless explicitly changed.

Answer

--privileged

Answer

--read-only=true