EX188 Practice Test 19 — 15 Questions

Question 1

How do you disconnect a running container from a custom network named 'mynet'?

Accepted Answer

podman network disconnect mynet mycontainer. 'podman network disconnect' removes a container from a specified network.

Answer

podman container disconnect mynet mycontainer

Answer

podman network remove mynet mycontainer

Answer

podman network detach mynet mycontainer

Question 2

You need to configure a container so that its port 8080 maps to port 80 on the host's loopback interface only (127.0.0.1). Which syntax is correct?

Accepted Answer

podman run -p 127.0.0.1:80:8080 myapp. Specifying the IP address in the port mapping string restricts binding to that specific interface, preventing external network access to the forwarded port.

Answer

podman run --net 127.0.0.1:80:8080 myapp

Answer

podman run -p 80:8080/127.0.0.1 myapp

Answer

podman run --publish 8080:80/lo myapp

Question 3

An administrator needs to configure a custom search domain for short-name image pulls across all users on a RHEL 9 system. Which configuration file must be edited?

Accepted Answer

/etc/containers/registries.conf. System-wide registry configurations, including unqualified-search-registries, are defined in /etc/containers/registries.conf.

Answer

/etc/containers/storage.conf

Answer

/etc/containers/policy.json

Answer

/etc/containers/registries.d/

Question 4

Which command starts services defined in a Podman Compose file in detached mode?

Accepted Answer

podman-compose up -d. 'podman-compose up -d' or 'podman compose up -d' starts all containers in background/detached mode.

Answer

podman-compose background

Answer

podman-compose start --detach

Answer

podman-compose run -d

Question 5

You are writing a Podman Compose file and want to ensure a service depends on another service being fully started before it initializes. Which directive should you use?

Accepted Answer

depends_on. The 'depends_on' directive controls startup order of services in compose files.

Answer

requires

Answer

wait_for

Answer

links_to

Question 6

An administrator needs to configure a local container registry mirror that redirects all requests for 'registry.redhat.io' to an internal caching proxy 'mirror.corp.local'. Which section of /etc/containers/registries.conf must be modified?

Accepted Answer

[[registry]] with prefix and location/mirrors parameters. Mirrors are configured under the [[registry]] table in registries.conf.

Answer

[registries.search]
mirrors = [...]

Answer

[mirror "registry.redhat.io"]

Answer

[cache.registry]
proxy = [...]

Question 7

Two containers running on the same custom user-defined bridge network need to communicate using container names as hostnames. What is required for this to work natively in Podman?

Accepted Answer

Nothing extra; user-defined bridge networks include built-in DNS resolution.. User-defined networks in Podman leverage CNI and netavark/aardvark-dns to provide automatic container name resolution out of the box.

Answer

You must use the default 'podman' bridge network.

Answer

You must edit /etc/hosts inside the containers manually.

Answer

You must manually link containers using the --link flag.

Question 8

Which environment file option can be used in a Podman Compose file to automatically load environment variables for service configuration?

Accepted Answer

env_file. The 'env_file' directive allows passing a .env file into containers or using them for interpolation.

Answer

environment_source

Answer

variables_file

Answer

load_env

Question 9

Which THREE configuration keys are valid within a service definition block in a Podman Compose file for managing container networking and ports? (Choose three.)

Accepted Answer

ports. 'ports', 'expose', and 'networks' are valid compose keys.

Answer

interfaces

Answer

firewall

Question 10

In a Podman Compose file, how do you define a custom network and connect a service to it?

Accepted Answer

Define networks at the root level and reference them under each service configuration.. Compose files require a top-level 'networks:' section and service-level 'networks:' declarations.

Answer

Use the 'links:' directive inside the service block exclusively.

Answer

Add a 'network_mode' string directly pointing to an external shell script.

Answer

Configure networking exclusively via command-line environment variables.

Question 11

An administrator needs to connect an already running container named 'web1' to an existing user-defined network named 'backend-net' without restarting the container. Which command accomplishes this?

Accepted Answer

podman network connect backend-net web1. The 'podman network connect' command attaches a running container to an additional network interface.

Answer

podman network attach backend-net web1

Answer

podman container modify --network backend-net web1

Answer

podman network join --container web1 backend-net

Question 12

You want to remove a custom Podman network named 'testnet', but it currently has active containers attached to it. What happens?

Accepted Answer

The deletion fails until all connected containers are stopped and disconnected.. Podman prevents network deletion while active endpoints/containers are connected to ensure integrity.

Answer

The network is removed, and the containers lose their network interface silently.

Answer

The containers are automatically disconnected and moved to the default bridge network.

Answer

The containers are automatically terminated and the network is removed.

Question 13

Which TWO scenarios correctly describe when an administrator should use the ':z' SELinux mount option instead of ':Z'? (Choose two.)

Accepted Answer

When content generated on the host needs to be safely read and written by multiple container instances using a shared label.. The ':z' option is used when volume content needs to be shared read-write among multiple containers simultaneously.

Answer

When disabling SELinux checks entirely for the volume.

Answer

When absolute isolation is required so that no other container can ever read the volume.

Answer

When mounting a host directory as strictly read-only.

Question 14

An engineer needs to inspect the low-level configuration details, mount points, and driver options of a named volume named 'app_vol'. Which command provides this information in JSON format?

Accepted Answer

podman volume inspect app_vol. 'podman volume inspect' retrieves detailed configuration and metadata for specified volumes.

Answer

podman volume show app_vol

Answer

podman volume status app_vol

Answer

podman inspect volume app_vol

Question 15

An administrator wants to create a named volume using a specific volume driver instead of the default local driver. Which flag should be used with 'podman volume create'?

Accepted Answer

podman volume create --driver nfs my_vol. The --driver (or -d) flag specifies the volume driver to use for managing the volume.

Answer

podman volume create --storage-driver nfs my_vol

Answer

podman volume create --plugin nfs my_vol

Answer

podman volume create -t nfs my_vol