EX188 Networking And Compose — Timed 20 Questions

Question 1

You are using Podman Compose and need to generate Kubernetes YAML manifests from your compose file. Which command achieves this?

Accepted Answer

podman-compose -f compose.yaml k8s. 'podman compose -f compose.yml generate' or 'podman-compose' equivalents can output Kubernetes YAML depending on the exact tooling, but podman-compose / podman compose supports translation flags or subcommands. Specifically, podman-compose provides a way to output K8s resources.

Answer

podman compose convert --kubernetes

Answer

podman-compose export --format kubernetes

Answer

podman generate kubernetes --compose compose.yaml

Question 2

Which THREE networking modes are natively supported out-of-the-box by Podman container execution? (Choose three.)

Accepted Answer

bridge. Podman natively supports bridge, host, and none network modes.

Answer

macvlan

Answer

overlay

Question 3

Which TWO options are valid when specifying protocol restrictions on a port mapping in Podman (e.g., -p)? (Choose two.)

Accepted Answer

udp. Both tcp and udp can be specified as protocols in port mappings.

Question 4

Which TWO states or details does 'podman network inspect' provide about a network? (Choose two.)

Accepted Answer

Subnet configuration. Inspect provides JSON output detailing driver, subnet, and connected containers.

Answer

Host CPU utilization

Answer

Kernel version

Answer

Container disk usage

Question 5

A developer writes a Podman Compose file and needs to generate corresponding Kubernetes YAML manifests to prepare for an OpenShift deployment. Which Podman Compose command performs this generation?

Accepted Answer

podman generate kube. Podman Compose supports the 'podman-compose generate' or generating output via Kubernetes integration tools, but specifically, podman play/generate or podman-compose options like converting to K8s can be managed. Wait, podman-compose doesn't natively have a direct 'generate' subcommand in all versions, but Podman itself provides 'podman generate kube'. Let's look at standard Podman K8s generation: 'podman generate kube' creates Kubernetes YAML from a pod or container.

Answer

podman kube create --compose

Answer

podman-compose to-kube

Answer

podman-compose export --kubernetes

Question 6

An administrator creates a custom CNI network using 'podman network create mynet' and wants to assign a static IP address to a container upon creation. Which option achieves this?

Accepted Answer

podman run --network mynet --ip 192.168.100.50 -d myimage. The --ip flag is used with 'podman run' on a user-defined bridge network to allocate a specific static IP address to the container interface.

Answer

podman run --network mynet:192.168.100.50 -d myimage

Answer

podman network connect --ip 192.168.100.50 mynet container_id

Answer

podman run --net-static-ip 192.168.100.50 -d myimage

Question 7

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 8

A container needs to be created that shares the host's network stack entirely, bypassing any NAT or virtual interface overhead. Which Podman flag achieves this?

Accepted Answer

--network host. Using --network host disables network isolation and places the container directly on the host's network namespace.

Answer

--share-net

Answer

--publish host

Answer

--net bridge

Question 9

Which Podman network mode completely isolates a container from any network communication, removing all interfaces except the loopback?

Accepted Answer

--network none. The 'none' network driver disables all external and internal networking for the container.

Answer

--network isolated

Answer

--network closed

Answer

--network disabled

Question 10

You need to inspect the configuration details, including subnet, gateway, and driver, of a custom Podman network named 'appnet'. Which command should you run?

Accepted Answer

podman network inspect appnet. 'podman network inspect' displays detailed low-level network configurations in JSON format.

Answer

podman inspect --network appnet

Answer

podman network show appnet

Answer

podman network status appnet

Question 11

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 12

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 13

How do you list all available Podman networks on your system?

Accepted Answer

podman network ls. 'podman network ls' lists all configured container networks.

Answer

podman network list

Answer

podman network status

Answer

podman network show

Question 14

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 15

How do you stop and remove containers, networks, and volumes created by a Podman Compose file?

Accepted Answer

podman-compose down. 'podman-compose down' tears down the entire application stack defined in the compose file.

Answer

podman-compose rm --all

Answer

podman-compose destroy

Answer

podman-compose stop --purge

Question 16

You need to configure a container port mapping in Podman Compose so that host port 80 forwards to container port 8080. Which YAML syntax is correct under the service definition?

Accepted Answer

ports:
  - "80:8080". The 'ports' directive uses strings or lists in 'HOST:CONTAINER' format.

Answer

publish:
  - 80->8080

Answer

expose:
  - "80:8080"

Answer

ports:
  container: 8080
  host: 80

Question 17

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 18

When inspecting the networking of a container using 'podman inspect', where is the IP address of the container located in the output JSON structure?

Accepted Answer

NetworkSettings.IPAddress. The NetworkSettings.IPAddress field contains the IPv4 address assigned to the container on its default network.

Answer

HostConfig.PortBindings.IP

Answer

Config.Network.IP

Answer

State.Networking.Address

Question 19

You wish to connect an already running container to an existing custom Podman network named 'mynet'. Which command should you use?

Accepted Answer

podman network connect mynet mycontainer. 'podman network connect' attaches a running or stopped container to a specified network.

Answer

podman network attach mynet mycontainer

Answer

podman container network-add mynet mycontainer

Answer

podman network join mynet mycontainer

Question 20

Which flag allows you to publish a container port to a random ephemeral port on the host interface?

Accepted Answer

-P. Using -P or --publish-all publishes all exposed ports to random high-numbered ports on the host.

Answer

-p random

Answer

-p 0:8080

Answer

--port dynamic