EX188 Networking And Compose — 20 Questions

Question 1

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

Accepted Answer

podman-compose down. The `podman-compose down` command is the standard way to stop and remove all resources defined in a Compose file, including containers, networks, and (with the `-v` flag) volumes. It mirrors the behavior of `docker-compose down`, providing a clean teardown of the entire application stack. This command ensures that no orphaned resources remain, which is critical for maintaining a clean environment.

Answer

podman-compose rm --all

Answer

podman-compose destroy

Answer

podman-compose stop --purge

Question 2

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 3

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. In `podman inspect` output, the container's IP address is found under `NetworkSettings.IPAddress`. This field contains the IPv4 address assigned to the container on its network. For IPv6, it would be under `NetworkSettings.GlobalIPv6Address`.

Answer

HostConfig.PortBindings.IP

Answer

Config.Network.IP

Answer

State.Networking.Address

Question 4

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. `depends_on` is the Compose directive that declares a startup dependency between services, ensuring the dependent service is started after its dependency. In Podman Compose and Docker Compose, this is the standard way to express ordering in a compose file.

Answer

requires

Answer

wait_for

Answer

links_to

Question 5

Which TWO commands or flags can be used to publish a container port to the host in Podman? (Choose two.)

Accepted Answer

-p. Both -p and --publish are valid flags for publishing ports in Podman.

Answer

--port

Answer

--expose

Question 6

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 7

When configuring a custom CNI network in Podman using 'podman network create', which TWO parameters can be explicitly defined via command-line flags during creation? (Choose two.)

Accepted Answer

--mtu. --subnet and --gateway can be specified during network creation.

Answer

--dns-server

Answer

--vlan-id

Question 8

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 9

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 10

When generating Kubernetes YAML using 'podman generate kubernetes', which TWO object types can be targeted or generated by the command? (Choose two.)

Accepted Answer

Deployment. Option A (Deployment) is correct because 'podman generate kube' (the Kubernetes YAML generator) can produce a Deployment object when the --type=deployment flag is used, wrapping the pod spec in a Deployment for replica management. Option C (Pod) is correct because the default output of 'podman generate kube' is a Pod object, which is the fundamental unit generated from a container or pod. Options B (DaemonSet), D (StatefulSet), and E (Ingress) are incorrect because the command does not support generating these object types; only Pod and Deployment are valid targets.

Answer

DaemonSet

Answer

StatefulSet

Answer

Ingress

Question 11

Which THREE subcommands are valid under 'podman-compose' (or 'podman compose') for managing container lifecycles and application stacks? (Choose three.)

Accepted Answer

logs. Option B, 'logs', is valid because podman-compose implements the Compose 'logs' subcommand to aggregate and display stdout/stderr from the containers in a stack, mirroring docker-compose logs. Option D, 'up', is correct because 'up' is the core Compose subcommand that creates and starts all services, networks, and volumes defined in the compose file, and podman-compose supports it. Option E, 'down', is correct because 'down' stops and removes the containers, networks, and (with -v) volumes created by 'up', and podman-compose provides this teardown subcommand. Option A, 'compile', is not a Compose lifecycle subcommand (it belongs to tools like podman-compose's internal build or other build systems), and Option C, 'deploy', is a Docker Swarm/stack-oriented subcommand not implemented as a standard podman-compose lifecycle command.

Answer

compile

Answer

deploy

Question 12

Which THREE methods or directives can be used to pass environment variables into containers via Podman Compose? (Choose three.)

Accepted Answer

env_file. Option B (env_file) is correct because Podman Compose supports the env_file directive, which reads variables from a file and injects them into the container's environment at runtime. Option D (Shell variable interpolation, e.g., ${VAR}) is correct because Compose files are processed with variable substitution, so values from the host shell or a .env file can be interpolated into the YAML and then passed as container environment variables. Option E (environment) is correct because the environment key in a Compose service definition explicitly sets environment variables inside the container, either as a list or key-value mapping. The unmarked options do not belong: sysctl_env and container_env are not valid Podman Compose directives, so they cannot be used to pass environment variables into containers.

Answer

sysctl_env

Answer

container_env

Question 13

Which TWO networking configurations are mandatory or automatically handled when creating a user-defined bridge network in Podman? (Choose two.)

Accepted Answer

Automatic IPsec tunneling. A bridge interface is created on the host, and IPAM allocates a subnet.

Question 14

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 15

Which THREE actions occur when a container is executed with the --network none flag? (Choose three)

Accepted Answer

No default gateway is configured in the container's routing table.. Option A is correct because with --network none Docker creates no external network path, so no default gateway route is installed in the container's routing table. Option D is correct because the container's network namespace is created with only the loopback interface (lo), which is brought up, and no veth pair or other interfaces are attached. Option E is correct because port publishing (-p) requires a network interface and NAT rules on a bridge or host network; with no network namespace connectivity, Docker cannot set up the port mapping and the flag has no effect or fails. Option B is wrong because sharing the host's physical NIC is the behavior of --network host, not --network none. Option C is wrong because assignment of a private IP on the default bridge happens with the default bridge network, whereas --network none provides no IP address at all.

Answer

The container automatically shares the host's physical network card.

Answer

The container is assigned a private IP address on the default bridge.

Question 16

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 combined with `--network mynet` is the correct way to assign a static IP to a container on a custom CNI network in Podman. The syntax `podman run --network mynet --ip 192.168.100.50 -d myimage` attaches the container to the named network and requests the specified IP from the network's IPAM range. The IP must fall within the subnet defined when the network was created.

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 17

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. The correct syntax for binding a published container port to a specific host IP is `-p HOST_IP:HOST_PORT:CONTAINER_PORT`. Option D, `-p 127.0.0.1:80:8080`, maps container port 8080 to host port 80, but only on the loopback interface 127.0.0.1, which is exactly what the question requires. This restricts external access so only processes on the host itself can reach the service.

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 18

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 19

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

Accepted Answer

--network none. The `--network none` option in Podman creates a container with a completely isolated network namespace that contains only the loopback interface (lo). No veth pair, no bridge attachment, and no external connectivity is configured, so the container cannot send or receive any network traffic beyond itself. This is the canonical way to run a container with zero network exposure for security-sensitive workloads.

Answer

--network isolated

Answer

--network closed

Answer

--network disabled

Question 20

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 <name>' returns detailed JSON configuration for the specified network, including subnet, gateway, driver, IPAM options, and connected containers. This is the correct command to inspect a custom Podman network's configuration details.

Answer

podman inspect --network appnet

Answer

podman network show appnet

Answer

podman network status appnet