EX188 Practice Test 2 — 30 Questions

Question 1

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?

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

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 2

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 3

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 4

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 5

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 6

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 7

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 8

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 9

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 10

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

Question 11

An administrator needs to configure system-wide registry search shortcuts so that developers can run 'podman pull rhel9' and Podman automatically expands it to 'registry.access.redhat.com/rhel9'. Which configuration file and parameter accomplish this?

Accepted Answer

/etc/containers/registries.conf using the unqualified-search-registries parameter. Unqualified search registries are configured in /etc/containers/registries.conf using the unqualified-search-registries array parameter.

Answer

/etc/sysconfig/podman using the SEARCH_REGISTRIES variable

Answer

/etc/containers/registries.d/default.yaml using the search-domains parameter

Answer

~/.config/containers/auth.json using the default-registry key

Question 12

An administrator needs to pause all processes inside a running container named db_master without stopping it. Which command accomplishes this?

Accepted Answer

podman pause db_master. podman pause suspends all processes in the specified container.

Answer

podman suspend db_master

Answer

podman freeze db_master

Answer

podman hold db_master

Question 13

You are optimizing a Containerfile using multi-stage builds to minimize image size. What is the key advantage of a multi-stage build in Podman?

Accepted Answer

It allows you to copy only finalized artifacts from a heavy build stage into a minimal production stage.. Multi-stage builds allow you to use multiple FROM instructions in a single Containerfile. Each FROM instruction starts a new stage with a different base, and you can copy artifacts from previous stages into the final stage, leaving behind build tools, compilers, and SDKs.

Answer

It automatically converts Dockerfiles into systemd service units.

Answer

It enables building container images concurrently across multiple remote container registries.

Answer

It eliminates the need for caching layers during the podman build process.

Question 14

When creating multi-architecture container images using podman build, how can you ensure that architecture-specific binaries are correctly handled when using instructions like COPY?

Accepted Answer

By running podman build separately for each architecture and combining them with podman manifest.. Podman supports building for multiple architectures using buildah/podman features, where TARGETPLATFORM, TARGETOS, and TARGETARCH build args are automatically available.

Answer

By setting the ARCH environment variable in the base image.

Answer

By manually editing the Containerfile to include architecture-specific IF/ELSE statements.

Question 15

A security team requires that all container processes run with a specific SELinux type instead of the default container_t. How can an administrator specify a custom SELinux type when launching a container with 'podman run'?

Accepted Answer

--security-opt label=type:custom_t. The '--security-opt' flag can be used to set custom SELinux labels (e.g., label=type:custom_t).

Answer

--selinux-type custom_t

Answer

--cap-add SELINUX

Answer

--env SELINUX_TYPE=custom_t

Question 16

Which TWO commands display information about container images present in local Podman storage? (Choose two.)

Accepted Answer

podman image inspect. 'podman images' and 'podman image inspect' display local image information.

Answer

podman container list

Answer

podman ps

Answer

podman volume ls

Question 17

An administrator needs to run a container that requires access to the host's network stack directly, bypassing network isolation. Which flag should be passed to 'podman run'?

Accepted Answer

--network host. Passing '--net=host' or '--network=host' disables network namespace isolation.

Answer

--share network

Answer

--privileged

Answer

--net bridge

Question 18

An administrator wants to immediately stop and remove a running container named temp_test in a single command. Which command should be used?

Accepted Answer

podman rm -f temp_test. The --rm flag with run automatically removes containers upon exit, but to remove an existing running container immediately, podman rm with -f can be used.

Answer

podman kill --remove temp_test

Answer

podman delete --force temp_test

Answer

podman stop --rm temp_test

Question 19

An administrator wants to view real-time container lifecycle events across the entire Podman system, such as container creation, starting, and stopping. Which command should be executed?

Accepted Answer

podman events. The podman events command monitors container events in real time.

Answer

podman monitor --stream

Answer

podman logs --follow --events

Answer

podman system trace

Question 20

An administrator needs to update the CPU shares (cpu-shares) of a running container named compute_job on the fly without stopping it. Which command should be used?

Accepted Answer

podman update --cpu-shares 512 compute_job. podman update modifies container configuration resources on a running container.

Answer

podman config compute_job cpu-shares=512

Answer

podman modify --cpu-shares 512 compute_job

Answer

podman set --shares=512 compute_job