EX188 Practice Exam 2 — 20 Questions

Question 1

A container named 'metrics' has been running for several hours, and an engineer needs to inspect its current resource consumption (CPU, memory, and network I/O usage). Which Podman command provides a live-updating stream of resource usage statistics for running containers?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

podman stats metrics. The 'podman stats' command displays a live stream of resource usage statistics for specified containers.

Answer

podman inspect metrics

Answer

podman top metrics

Answer

podman system df metrics

Question 2

An administrator wants to run a container with a custom health check command that disables health checking entirely for a container that inherited one from its base image. Which flag achieves this?

Accepted Answer

--health-cmd=none. Setting --health-cmd=none disables the health check inherited from the base image.

Answer

--health-enabled=false

Answer

--disable-health

Answer

--no-healthcheck

Question 3

An administrator is troubleshooting process execution and live configuration updates on a running container. Which TWO commands allow interacting with processes or updating resource limits on the fly? (Choose TWO)

Accepted Answer

podman update. podman top shows container processes, and podman update modifies container resources live.

Answer

podman exec-top

Answer

podman adjust

Answer

podman modify

Question 4

You are troubleshooting a build where a RUN instruction fails because it cannot reach a remote URL to download a file. The local network uses an HTTP proxy. How should you pass the proxy settings to the build command without hardcoding them into the image?

Accepted Answer

podman build --build-arg HTTP_PROXY=http://proxy.example.com:8080 .. Build arguments can be passed via --build-arg to provide proxy settings dynamically.

Answer

podman build --proxy http://proxy.example.com:8080 .

Answer

podman build --env HTTP_PROXY=http://proxy.example.com:8080 .

Answer

podman build --set-proxy http://proxy.example.com:8080 .

Question 5

An auditor notices that a container image runs its main application process as the 'root' user by default. Which Containerfile instruction can be added to ensure the container runs as a non-privileged user named 'appuser'?

Accepted Answer

RUN useradd -u 1000 appuser && chown -R appuser /app
USER appuser. Using USER appuser ensures that subsequent commands and the runtime process execute under that user account.

Answer

EXEC appuser

Answer

PRIVILEGE drop appuser

Answer

SECURITY --user=appuser

Question 6

An administrator needs to check the disk space consumption of all containers, images, and volumes managed by Podman. Which command should be run?

Accepted Answer

podman system df. podman system df shows disk usage by Podman objects.

Answer

podman storage show

Answer

podman disk usage

Answer

podman inspect --disk

Question 7

An administrator is configuring container health checks and wants to review health status or force immediate actions. Which TWO of the following statements or commands are accurate regarding Podman health checks? (Choose TWO)

Accepted Answer

podman inspect --format='{{json .State.Health.Status}}' can be used to check container health status.. podman inspect with health format templates can retrieve health status, and health checks can be defined at run time using --health-cmd.

Answer

Container health statuses are automatically logged to /var/log/podman-health.log on the host.

Answer

podman stop automatically triggers a health check before shutting down.

Answer

podman health-check status is a valid built-in standalone top-level command.

Question 8

An administrator needs to view logs or attach to a running container to troubleshoot an issue. Which TWO commands can be used to interact with container output streams? (Choose TWO)

Accepted Answer

podman attach. podman logs retrieves logged output, and podman attach connects to container input/output streams.

Answer

podman stream

Answer

podman view-logs

Answer

podman output

Question 9

An administrator needs to clean up stopped containers and unused data to reclaim disk space. Which TWO commands can be used to remove containers? (Choose TWO)

Accepted Answer

podman rm. podman rm removes specified containers, and podman container prune removes all stopped containers.

Answer

podman image prune

Answer

podman rmi

Answer

podman system clean

Question 10

An administrator wants to modify container settings or state. Which TWO of the following commands are valid Podman subcommands for container management? (Choose TWO)

Accepted Answer

podman restart. podman rename and podman restart are valid subcommands.

Answer

podman reconfigure

Answer

podman alter

Answer

podman modify

Question 11

A container named app_server is running and consuming excessive CPU. An administrator needs to gracefully stop this container with a 30-second timeout before forcing termination. Which command accomplishes this?

Accepted Answer

podman stop --time 30 app_server. The podman stop command stops one or more running containers and accepts a -t or --time option to specify the seconds to wait before killing the container.

Answer

podman kill --signal SIGTERM --timeout 30 app_server

Answer

podman halt -s 30 app_server

Answer

podman terminate --grace-period=30 app_server

Question 12

How does Podman's rootless build architecture handle volume mounts or privileged operations specified within a RUN instruction in a Containerfile?

Accepted Answer

Rootless builds execute within user namespaces, mapping root inside the container to an unprivileged user on the host, restricting certain host-level operations.. Rootless Podman utilizes user namespaces and often relies on tools like buildah or fuse-overlayfs to perform builds without root privileges on the host.

Answer

Rootless builds cannot execute RUN instructions that install RPM packages using dnf.

Answer

Rootless builds automatically elevate privileges via sudo when a RUN instruction requires root access.

Answer

Rootless builds require the buildah daemon to be running as root in systemd.

Question 13

Which instruction documents the network ports on which a container listens at runtime?

Accepted Answer

EXPOSE. EXPOSE functions as a type of documentation between the person who builds the image and the person who runs the container.

Answer

LISTEN

Answer

PORT

Answer

OPEN

Question 14

An administrator needs to run a container named 'web01' using Podman in the background using the image registry.access.redhat.com/ubi8/httpd-24:latest. Which command correctly starts this container in detached mode and maps port 8080 on the host to port 80 in the container?

Accepted Answer

podman run -d --name web01 -p 8080:80 registry.access.redhat.com/ubi8/httpd-24:latest. The correct command uses 'podman run -d' for detached mode, '--name web01' to set the name, '-p 8080:80' for port mapping, and the correct image reference.

Answer

podman start -d --name web01 -p 8080:80 registry.access.redhat.com/ubi8/httpd-24:latest

Answer

podman container create -d --name web01 -p 8080:80 registry.access.redhat.com/ubi8/httpd-24:latest

Answer

podman run -b --name web01 -p 80:8080 registry.access.redhat.com/ubi8/httpd-24:latest

Question 15

You want to build an image that has a build-time argument named 'VERSION'. How do you declare this variable inside the Containerfile so it can be used during the build steps?

Accepted Answer

ARG VERSION. The ARG instruction defines a variable that users can pass at build-time with podman build --build-arg =.

Answer

DEFINE VERSION

Answer

ENV VERSION=1.0

Answer

VAR VERSION

Question 16

You are writing a Containerfile and need to ensure that the default command executed when the container starts can be easily overridden by passing arguments on the podman run command line. Which instruction should you use?

Accepted Answer

CMD. CMD provides default arguments for an entrypoint or a default command, which is easily overridden by command-line arguments.

Answer

RUN

Answer

EXEC

Answer

ENTRYPOINT

Question 17

A developer needs to optimize image size by removing build caches and temporary package manager cache files within the same RUN instruction. Why must this be done in a single RUN instruction?

Accepted Answer

Because file deletions in separate layers do not reduce the final image size due to the layered filesystem.. Docker/Podman image layers are read-only snapshots. Deleting a file in a later layer only hides it; it does not remove it from previous layers.

Answer

Because package managers lock the database across different layers.

Answer

Because the container build engine will fail if cache cleanup happens in a separate layer.

Answer

To ensure environment variables persist between installation and cleanup.

Question 18

An administrator needs to list all containers, including both running and stopped ones, on the system. Which command should be used?

Accepted Answer

podman ps -a. podman ps lists containers, and the -a or --all flag includes stopped containers.

Answer

podman status --all

Answer

podman list --all

Answer

podman containers show

Question 19

An administrator is troubleshooting a misbehaving container and needs to examine its output logs and event history. Which TWO commands are appropriate for this task? (Choose TWO)

Accepted Answer

podman logs. podman logs retrieves container stdout/stderr, and podman events streams system-wide container events.

Answer

podman inspect-logs

Answer

podman history

Answer

podman trace

Question 20

An administrator wants to generate a systemd unit file for an existing Podman container named 'app_server' so that it can be managed as a system service. Which command should be used to generate this unit file and write it directly to the user systemd directory?

Accepted Answer

podman generate systemd --new --files --name app_server. The 'podman generate systemd' command is used to create systemd unit files, and the '--new' flag ensures the unit file creates a new container on start rather than relying on an existing stopped container.

Answer

podman export systemd app_server > /etc/systemd/system/app_server.service

Answer

podman service generate --container app_server --output ~/.config/systemd/user/

Answer

podman systemd create --name app_server > ~/.config/systemd/user/container-app_server.service